Photographing apparatus with image-blur suppression mechanism

The present application claims the priority benefit of Japanese Patent Application 2005-305840 filed on Oct. 20, 2005, the contents of which are incorporated herein by reference.

1. Field of the Invention

The present invention relates to a photographing apparatus which obtains a subject image by forming the subject image on a photographing element used for producing image data, especially to a photographing apparatus with an image-blur suppression mechanism to take a subject image with image blurring suppressed or compensated by moving the photographing element to follow the subject image moved by a camera shake.

2. Description of Related Art

Heretofore, as disclosed in Japan Patent Laid-Open No. 2004-274242, there is known a photographing apparatus, for example a digital camera, which is provided with an image-blur suppression mechanism. The photographing apparatus includes a CCD as a photographing element, a holding tube mounted to a main body of the photographing apparatus for housing a lens barrel at a photographing optical axis, a mount stage which is disposed at one end of the holding tube for mounting the CCD thereon, and a computation device disposed in the main body.

The mount stage is held at a guide stage, which is fixed in the main body with respect to the photographing optical axis, in such a way that the mount stage is movable on the guide stage by a magnetic force from a permanent magnet and a coil opposing to the permanent magnet along an XY plane which is perpendicular to the photographing optical axis as Z axis.

The computation device, which is connected to the CCD electrically, determines inclinations of the main body at X and Y axial directions and controls the CCD to follow a displacement of the subject image caused by a camera shake through varying an electric voltage applied to the coil based on the inclination determination result. The computation device performs an image formation process and an image display process etc. based on image signals output from the CCD.

For the above mentioned digital camera with an image-blur suppression mechanism, since the computation device is disposed in the main body, there occurs a variation on a relative distance between the CCD and the computation device when the image-blur suppression is performed by moving the CCD along the XY plane, thus there has been proposed a flexible base plate to connect the CCD and the computation device therewith.

However, since the movement of the CCD for the image-blur suppression is a minute position adjustment performed by the magnetic force from the permanent magnet and the coil opposing to the permanent magnet, a deformation force resulted from a bending deformation of the flexible base plate corresponding to the variation on the relative distance between the CCD and the computation device may become a hindrance to the proper movement of the CCD, thus there arises a problem that the image-blur suppression may not be performed properly.

The present invention has been accomplished in view of the aforementioned problems and it is, therefore, an object of the present invention to provide a photographing apparatus with an image-blur suppression mechanism which performs image blurring suppression properly when a computation device disposed in a main body of the photographing apparatus and a photographing element to be movable along an XY plane are electrically connected.

To accomplish the objective described above, there is provided a photographing apparatus according to the present invention comprising an image-blur suppression mechanism which moves a photographing element on a photographing plane of which a subject image is formed in an XY plane which is parallel to the photographing plane to follow a displacement of the subject image caused by the camera shake based on a target value obtained by setting an intersection point of Z axis which is a photographing optical axis and the photographing plane which is perpendicular to Z axis as a zero point to calculate a displacement amount of the subject image which is caused by the camera shake detected on a main body from the zero point as the target value; a computation device which is provided in the main body to process signals from the photographing element and drive the image-blur suppression mechanism; and a flexible base plate which is disposed in the main body with one end connected to the photographing element and the other end fixed relative to the photographing optical axis for connecting the computation device, wherein the flexible base plate includes a connection extension section which is extended to connect the one end to the other end and has a first extension part which is extended along the XY plane starting from the one end, a second extension part which is connected to the first extension part extending toward the subject viewing from the photographing element, a third extension part which is connected to the second extension part extending parallel to the XY plane, and a fourth extension part which is connected to the third extension part extending in a direction away from the subject viewing from the photographing element; the connection extension section is folded through a plastic deformation to form a folding line between the first and second extension parts, the second and third extension parts, the third and fourth extension parts, and the fourth extension part and the other end, respectively; and an intersection line between a plane containing the second extension part and the XY plane and an intersection line between a plane containing the fourth extension part and the XY plane are intersected with XY axes, respectively.

FIG. 1 is a front view of a digital camera according to the present invention;

FIG. 2 is a rear view of the digital camera according to the present invention;

FIG. 3 is a top view of the digital camera according to the present invention;

FIG. 4 is a circuit block view schematically showing an inner system configuration of the digital camera according to the present invention;

FIG. 5 is a flow chart schematically explaining a general operation of the digital camera according to the present invention;

FIG. 6 is a view showing a principle of an image-blur suppression of the digital camera according to the present invention, wherein FIG. 6A shows an inclination of the digital camera and FIG. 6B is an enlarged partial view showing a relationship between a photographing plane of a CCD and a photographing lens of the digital camera according to the present invention;

FIG. 7 is a front view showing a holding tube for housing a lens barrel of the digital camera according to the present invention;

FIG. 8 is a vertical section view of the holding tube in FIG. 7 ;

FIG. 9 is a rear view of the holding tube in FIG. 7 , wherein FIG. 9A is a view showing that a flexible base plate is not mounted and FIG. 9B is a view showing that the flexible base plate is mounted;

FIG. 10 is an exploded perspective view of a CCD stage of the digital camera according to the present invention;

FIG. 11 is an enlarged partial section view of the holding tube in FIG. 9B sectioned along an II-II line;

FIG. 12 is an explanatory view showing a zero point retention mechanism according to the present invention, wherein FIG. 12A is a perspective view showing a connection relationship among the CCD stage, a stepping motor and a conversion mechanism and FIG. 12B is an enlarged partial view of the conversion mechanism;

FIG. 13 is a schematic diagram showing a cam groove of a rotation transmitting gear, wherein FIG. 13A is a bottom view of the rotation transmitting gear, FIG. 13B is a section view of the rotation transmitting gear in FIG. 13A sectioned along a circular dotted and dashed line V; FIG. 13C is a view showing a state when a cam pin slides along an inclination surface of the cam groove to push up the rotation transmitting gear toward a base member, FIG. 13D is a view showing a state when the cam pin is contacted to a apex flat part of the cam groove to push up the rotation transmitting gear to a utmost high position, and FIG. 13E is a view showing a state when the cam pin is contacted to a valley flat part of the cam groove to push down the rotation transmitting gear to a utmost low position;

FIG. 14 is an explanatory view showing a fitted state between a holding pin and a recess portion, wherein FIG. 14A is an enlarged partial section view showing a close fitted state between the holding pin and the recess portion and FIG. 14B is an enlarged partial section view showing a separating state between the holding pin and the recess portion;

FIG. 15 is a view of the flexible base plate before superimposed;

FIG. 16 is a view showing a connection state of the flexible base plate before superimposed to the CCD stage;

FIG. 17 is a view showing a superimposed stage of a connection extension section of the flexible base plate;

FIG. 18 is a perspective view schematically showing a disposition relationship between the CCD stage and the flexible base plate, wherein FIG. 18A , FIG. 18B and FIG. 18C are views viewing from different angles;

FIG. 19 is a circuit block view of the zero point retention mechanism according to the present invention;

FIG. 20 is a flow chart showing an example of a control procedure of the zero point retention mechanism;

FIG. 21 is a circuit block view showing an example of a detection circuit of an image-blur suppression mechanism;

FIG. 22 is a circuit block view showing an example of a control circuit of the image-blur suppression mechanism;

FIG. 23 is a flow chart showing an example of a setting procedure of variation compensation according to the present invention;

FIG. 24 is a flow chart showing an example of a control procedure of the image-blur suppression mechanism;

FIG. 25 is a circuit block view showing a variant example of a feedback circuit;

FIG. 26 is a flow chart showing a suppression procedure of the image-blur suppression mechanism of the digital camera according to the present invention;

FIG. 27 is a timing chart showing an example of the suppression procedure of the image-blur suppression mechanism when a release switch is half and fully pressed in a two-stage press procedure according to the present invention;

FIG. 28 is a timing chart showing an example of a release procedure of the image-blur suppression mechanism according to the present invention; and

FIG. 29 is a timing chart showing an example of the suppression procedure of the image-blur suppression mechanism when the release switch is fully pressed at a burst according to the present invention.

Hereinafter, a digital camera as a photographing apparatus with an image-blur suppression mechanism according to the present invention will be described in detail with reference to the drawings. Herein, the image-blur suppression mechanism is a mechanism used to suppress or compensate image blurring which occurs when the digital camera loses its stability which is usually caused by for example a camera shake.

1. General Configuration of the Digital Camera

FIG. 1 , FIG. 2 and FIG. 3 show a front view, a rear view and a top view respectively of the digital camera (hereinafter, referred to as the camera) according to the present invention and FIG. 4 is a circuit block view schematically showing an inner system configuration of the digital camera.

A top surface of a main body of the camera is provided with a release switch (release shutter) SW 1 and a mode dial SW 2 as shown in FIG. 1 and a sub liquid crystal display (abbreviated as sub LCD) 1 as shown in FIG. 3 .

As shown in FIG. 1 , a front surface of the main body of the camera is provided with a lens barrel unit 7 including a photographing lens, an optical finder 4 , a strobe light unit 3 , a ranging unit 5 , a remote control light-receiving unit 6 and a lid of SD card/battery room 2 .

As shown in FIG. 2 , a back surface of the camera DCa is provided with a power switch SW 13 , an LCD monitor 10 , an AF LED 8 , a strobe LED 9 , the optical finder 4 , a wide-angle zoom switch SW 3 , a telescopic zoom switch SW 4 , a self-timer set/reset switch SW 5 , a menu switch SW 6 , an upward/strobe switch SW 7 , a rightward switch SW 8 , a display switch SW 9 , a downward/macro switch SW 10 , a leftward/image confirmation switch SW 11 , an OK switch SW 12 and an image-blur suppression switch SW 14 .

Since functions or actions of the above mentioned members are well known in the art, descriptions of them are omitted, thus an inner system configuration of the camera will be described in the following.

2. Inner System Configuration of the Camera

As shown in FIG. 4 , numeral 104 represents a digital still camera processor (hereinafter referred to as a processor).

The processor 104 comprises a A/D converter 10411 , a CCD 1 signal processing block 1041 , a CCD 2 signal processing block 1042 , a CPU block 1043 , a local SRAM 1044 , a USB block 1045 , a serial block 1046 , a JPEG CODEC block 1047 which performs JPEG compression and decompression of an image data, a RESIZE block 1048 which scales up or down the image data through interpolation, a TV signal display block 1049 which converts the image data into a video signal so as to display the image on an external display device such a liquid crystal display or TV etc., and a memory card controller block 10410 . These blocks are connected with each other by a bus line.

An outside of the processor 104 is provided with a SDRAM 103 which stores RAW-RGB data, YUV data and JPEG data of the image and the SDRAM is connected to the processor 104 via a memory controller (not shown) and a bus line.

The outside of the processor 104 is further provided with a RAM 107 , an embedded memory 120 which stores a photographed image data even if an external memory card is not loaded and a ROM 108 which stores a controlling program, and these are also connected to the processor 104 via a bus line.

The controlling program is loaded to a main memory (not shown) of the processor 104 when the power switch SW 13 is set ON. The processor 104 performs an action control on each unit according to the controlling program and stores a control data and a parameter etc. temporarily in the RAM 107 .

The lens barrel unit 7 comprises a lens barrel which includes a zoom optical system 71 having a zoom lens 71 a , a focus optical system 72 having a focus lens 72 a , an aperture stop unit 73 having an aperture stop 73 a and a mechanical shutter optical system 74 having a mechanical shutter 74 a.

The zoom optical system 71 , the focus optical system 72 , the aperture stop unit 73 and the mechanical shutter optical system 74 are driven by a zoom motor 71 b , a focus motor 72 b , an aperture stop motor 73 b and a mechanical shutter motor 74 b , respectively.

These motors are driven by a motor driver 75 which is controlled by the CPU block 1043 of the processor 104 .

A subject image is formed on the CCD 101 through each lens system of the lens barrel unit 7 . The CCD 101 converts the subject image into an image signal, and outputs the image signal to an F/F-IC 102 . The F/E-IC 102 includes a CDS 1021 which performs a correlated double sampling to eliminate image noise, an AGC 1022 which performs automatic gain control and an A/D converting unit 1023 which converts an analogue image signal to the digital one.

That is to say, the F/F-IC 102 performs a predefined processing on the image signal and converts it from the analogue signal to the digital signal, then outputs the digital signal to the CCD 1 signal processing block 1041 of the processor 104 .

These signal processing operations are performed via a TG 1024 according to a vertically synchronized signal VD and a horizontally synchronized signal HD outputted from the CCD 1 signal processing block 1041 of processor 104 . The TG 1024 generates a driving timing signal based on the vertically synchronized signal VD and the horizontally synchronized signal HD.

The CPU block 1043 of the processor 104 is configured to control a sound recording circuit 1151 which performs a sound recording operation. A sound is converted to a sound recording signal by a microphone 1153 and amplified by a microphone amplifier 1152 . The sound recording circuit 1151 records the amplified signal according to a command.

The CPU block 1043 also controls operations of a sound reproduction circuit 1161 . The sound reproduction circuit 1161 is configured to output sound signals stored in a proper memory according to a command to an audio amplifier 1162 and reproduce the sound signals from a speaker 1163 .

Furthermore, the CPU block 1043 controls a strobe light circuit 114 for making the strobe light unit 3 emit lights. In addition, the CPU block 1043 also controls the ranging unit 5 .

The CPU block 1043 is connected to a sub-CPU 109 of the processor 104 and the sub CPU 109 controls displaying on the sub LCD 1 via a CCD driver 111 . The sub CPU 109 is further connected with the AF LED 8 , the strobe LED 9 , the remote-control light-receiving unit 6 , an operation key unit having the operation switches SW 1 to SW 14 , and a buzzer 113 .

The USB block 1045 is connected to a USB connector 122 , and the serial block 1046 is connected to a RS-232C connector 1232 through a serial driver circuit 1231 . The TV signal display block 1049 is connected to the LCD monitor 10 via an LCD driver 117 and to a video jack 119 for connecting the camera to an external display device such as TV and the like via a video amplifier 118 which converts the TV signal output from the TV signal display block 1049 to a signal of an impedance 75 Ω. The memory card controller block 10410 is connected to a contact point between a memory card throttle 121 and a memory card.

The LCD driver 117 functions not only to drive the LCD monitor 10 but also to convert the TV signal output from the TV signal display block 1049 to a signal to be displayed on the LCD monitor 10 . The LCD monitor 10 is used to monitor the subject state before photographing, confirm a photographed image and display a photographed image stored in the memory card or the embedded memory 120 .

The main body of the camera is disposed with a holding tube (to be described hereinafter) which constitutes a part of the lens barrel unit 7 . The holding tube is provided with a CCD stage 1251 movable along an XY plane. The CCD 101 is mounted at the CCD stage 1251 which is included in the image-blur suppression mechanism, a detailed mechanical configuration of which will be described hereinafter.

The CCD stage 1251 is driven by an actuator 1255 which is hence controlled by a driver 1254 including coil drives MD 1 and MD 2 . The driver 1254 is connected to an analogue-digital converter circuit IC 1 which is then connected to the ROM 108 and receives the control data from the ROM 108 .

The holding tube is provided with a zero point retention mechanism 1263 to retain the CCD stage 1251 at the zero point when the image-blur suppression switch SW 14 and the power switch SW 13 are off. The zero point retention mechanism 1263 is controlled by an actuator, such as a stepping motor STM 1 driven by a driver 1261 to which the control data from the ROM 108 is output.

The CCD stage 1251 is attached with a position detecting element 1252 , which outputs a detected result to an amplifier 1253 to be amplified and output to the A/D converter 10411 . A gyro sensor 1241 is disposed in the main body of the camera to detect rotations along the X and Y axial directions, and a detected result from the gyro sensor 1241 is output to the A/D converter 10411 via a low-pass filter and amplifier 1242 .

3. General Operations of the Camera

The processor 104 determines whether the mode dial SW 2 is set to a photographing mode or a replay mode (Step S 1 in FIG. 5 ). If the mode dial SW 2 is set to the photographing mode, the camera will be started in the photographing mode. While if the mode dial SW 2 is set to the replay mode, the camera will be started in the replay mode.

Also as shown in FIG. 4 , the processor 104 controls the motor driver 75 to move the lens barrel of the lens barrel unit 7 to a proper photographing position. Furthermore, the processor 104 controls to apply the power to each circuit of the CCD 101 , F/E-IC 102 and LCD monitor 10 etc for a ready operation to start a finder mode.

In the finder mode, incoming lights to the CCD 101 through each lens system are photo-electrically converted into RGB analog signals and transmitted to the F/E-IC 102 including the CDS circuit 1021 , the AGC 1022 and the A/D converter 1023 . The A/D converter 1023 converts the analog signals to digital signals, and the digital signals are converted to YUV signals by a YUV converter disposed in a digital signal processor IC (the SDRAM 103 ) and written into a frame memory by the memory controller not shown.

The YUV signals are retrieved by the memory controller, and sent to a TV (not shown) or the LCD monitor 10 through the TV signal display block 1049 for a display of the photographed image. This processing is performed at an interval of 1/30seconds, thus the display of the photographed image in the finder mode will be renewed at every 1/30seconds. In other words, a monitoring processing is performed here (Step S 2 in FIG. 5 ). Next, whether or not the mode dial SW 2 has been switched is determined (Step S 3 in FIG. 5 ). If the mode dial SW 2 remains in the photographing mode, a photographing processing is performed through operations of the release switch SW 1 (Step S 4 in FIG. 5 ).

In the replay mode, the processor 104 controls the photographed image to be displayed on the LCD monitor 10 (Step S 5 in FIG. 5 ). Next, whether or not the mode dial SW 2 has been switched is determined by the processor 104 (Step S 6 in FIG. 5 ). If the mode dial SW 2 has been switched over to a different mode, the process moves to S 1 , while if the mode dial SW 2 remains in the replay mode, the process repeats from S 5 .

Thus, the processor 104 and the F/E-IC 102 function as a computation device to process signals from the CCD 101 . The computation device functions to drive the image-blur suppression mechanism when the image-blur suppression is performed, which will be described hereinafter.

4. Principal of the Image-blur Suppression

FIG. 6 shows a principal of the image-blur suppression. FIG. 6A shows a state of the digital camera without the camera shake depicted in solid lines and a state of the digital camera inclined by the camera shake depicted in dot lines. FIG. 6B is an enlarged partial view showing a relationship between a photographing plane of the CCD 101 and the photographing lens of the camera main body.

When there is no camera shake to the camera, the photographing plane of the CCD 101 is position at a position P 1 , in other words, a central position, and the subject image is projected at the zero point O. In the present embodiment, the camera is presumed to be inclined by the camera shake at an angle of θ (θx, θy). Accordingly, the photographing plane is moved to a position P 2 and the subject image is projected at a position O′. Thus, the image-blur suppression mechanism functions to move the photographing plane in parallel a dx along X axial direction and a dy along Y axial direction such that the photographing plane are positioned at P 1 and the subject image are projected again at the zero point O.

5. Mechanical Configuration of the Image-blur Suppression Mechanism

In FIG. 7 to FIG. 9 , numeral 10 represents the holding tube having a boxy shape, an inner part of which is a space for holding the lens barrel therein. The holding tube 10 is disposed in the main body at a defined position in relation to a photographing optical axis. A rear surface of the holding tube 10 is attached with a base member 11 which is a plate of a roughly rectangular shape in whole. A helicoid 12 is formed at an inner peripheral wall of the holding tube for extending or collapsing the lens barrel. The holding tube 10 has at least two corners cutout to form one corner portion 10 a as an attaching portion for the stepping motor STM 1 and the other corner portion 10 b as a folding space for a flexible base plate 20 which will be described hereinafter.

The CCD stage 1251 is provided at the base member 11 . The CCD stage 1251 includes substantially an X direction stage 13 of an annular frame shape, a Y direction stage 14 of a rectangular shape and a mount stage 15 , as shown in the exploded view in FIG. 10 .

The X direction stage 13 is fixed at the base member 11 . In the X direction stage 13 , there are provided a pair of guide shafts 13 a and 13 b extending along X axial direction, and four permanent magnets 16 a to 16 d of a cubic shape. The guide shafts 13 a and 13 b are disposed with a separation distance along Y axial direction. The four permanent magnets 16 a to 16 d are provided in the XY plane in pair with one pair of the permanent magnets 16 a and 16 b disposed in parallel with each other with a separation distance along Y axial direction and the other pair of the permanent magnets 16 c and 16 d disposed in parallel with each other with a separation distance along X axial direction.

In the present embodiment, the pair of the guide shafts 13 a and 13 b are configured to pass through the pair of the permanent magnets 16 a and 16 b but not limited to the configuration; it is also preferable to dispose the pair of the permanent magnets 16 a and 16 b in parallel with the pair of the guide shafts 13 a and 13 b.

In the Y direction stage 14 , there are provided a pair of guide shafts 14 a and 14 b extending along Y axial direction, two pairs of groove portions 17 a and 17 a ′, 17 b and 17 b ′. The guide shafts 14 a and 14 b are disposed with a separation distance along Y axial direction. The two pairs of groove portions 17 a and 17 a ′, 17 b and 17 b ′ which are formed with a separation distance along Y axial direction opposing to each other along X axial direction with a separation distance are supported by the pair of guide shafts 13 a and 13 b respectively. As a result, the Y direction stage 14 is movable along X axial direction.

The mount stage 15 includes a pair of coil attaching plates 15 a and 15 b extending out to X axial direction and a pair of coil attaching plates 15 c and 15 d extending out to Y axial direction. The CCD 101 is fixed at the center of the mount stage 15 . In the mount stage 15 , there are also provided at the same side with the photographing plane of the CCD 101 with two pairs of groove portions (numerals omitted) which are formed with a separation distance along X axial direction opposing to each other along Y axial direction with a separation distance are supported by the pair of guide shafts 14 a and 14 b respectively. As a result, the mount stage 15 is movable along X and Y axial directions in whole.

A protection plate 19 is attached on a surface opposing to the photographing plane of the CCD 101 . A recess portion 19 a of a tapered shape is formed in the center of the protection plate 19 , whose functions will be described hereinafter.

Coiled bodies COL 1 and COL 1 ′ which are flat and convoluted are attached on the pair of coil attaching plates 15 a and 15 b , respectively. The coiled bodies COL 1 and COL 1 ′ are connected in series. Similarly, coiled bodies COL 2 and COL 2 ′ which are flat and convoluted are attached on the pair of coil attaching plates 15 c and 15 d , respectively. The coiled bodies COL 2 and COL 2 ′ are also connected in series.

The coiled bodies COL 1 and COL 1 ′ are confronted by the permanent magnets 16 c and 16 d , respectively and the coiled bodies COL 2 and COL 2 ′ are confronted by the permanent magnets 16 a and 16 b , respectively. The pair of coiled bodies COL 1 and COL 1 ′, the pair of COL 2 and COL 2 ′ function to move the CCD 101 along X axial direction and Y axial direction, respectively.

As shown in FIG. 9 , an adsorption bar 35 is disposed in the respective of the coiled bodies COL 1 and COL 1 ′ so as to intersect the respective of the coiled bodies COL 1 and COL 1 ′ along X axial direction.

In the present embodiment, a hall element is used in the position detecting element 1252 . At one of the coil attaching plates 15 a and 15 b , for example, the coil attaching plate 15 b is provided with a hall element 1252 a . Similarly, a hall element 1252 b is provided at one of the coil attaching plates 15 c and 15 d , for example, the coil attaching plate 15 d.

The CCD 101 is connected to the F/E IC 102 electrically via the flexible base plate 20 as shown in FIG. 11 . The hall elements 1252 a and 1252 b are connected electrically to the amplifier 1253 which is an operational amplifier via the flexible base plate 20 and each of the coiled bodies COL 1 , COL 1 ′, COL 2 and COL 2 ′ is connected electrically to the driver 1254 which is a coil driver.

As shown at an enlarged view in FIG. 11 and FIG. 12 , the zero point retention mechanism 1263 includes the stepping motor STM 1 , whose mechanical configuration will be described in detail at first, leaving descriptions on driving and controlling of the stepping motor STM 1 hereinafter.

As shown in FIG. 7 and FIG. 11 , the stepping motor STM 1 is disposed at the corner portion 10 a of the holding tube 10 . An output shaft 20 ′ of the stepping motor STM 1 is provided with an output gear 21 . The corner portion 10 a is provided with a conversion mechanism 22 which converts a rotational movement to a linear movement.

The conversion mechanism 22 includes a rotation transferring gear 23 , a spring bearing member 27 , a reciprocating shaft 24 , a coil biasing spring 25 and a spring retention plate 26 . The corner portion 10 a of the holding tube 10 is provided with a pair of supporting portions 28 and 29 with a separation distance along Z axial direction. In the present embodiment, the supporting portion 28 is configured as a motor attaching plate. The reciprocating shaft 24 is supported by crossing the motor attaching plate 29 and the supporting portion 29 . The rotation transferring gear 23 is disposed to be rotationally supported by the reciprocating shaft 24 and meshed with the output gear 21 between the pair of supporting portions 28 and 29 .

One end portion of the reciprocating shaft 24 penetrates the supporting portion 29 , confronting a back surface of the base member 11 . The coil biasing spring 25 is provided between the spring bearing member 27 and the supporting portion 29 to bias the reciprocating shaft 24 toward the supporting portion 28 . The reciprocating shaft 24 includes a ramp portion 24 a engaging with a shaft hole at an end portion of the rotation transferring gear 23 .

As shown in FIGS. 13A to 13E , there is formed a cam groove 31 at the end portion of the rotation transferring gear 23 , extending around the rotation transferring gear 23 . The cam groove 31 includes a flat valley floor 31 a , a flat peak 31 b , an inclination surface 31 c inclining continuously from the flat valley floor 31 up to the flat peak 31 b and a sharp wall 31 d formed between the flat valley floor 31 and the flat peak 31 b as a contacting wall for a cam pin 32 to be described hereinafter.

There is fixed at the supporting portion 28 the cam pin 32 , a top end of which contacts the cam groove 31 in such a way that it is sidable along the cam groove 31 . A rotation length of the flat valley floor 31 a from the sharp wall 31 d to an inclination starting point 31 e of the inclination surface 31 c is configured to be equivalent to 2 pulses of a rotation control signal of the stepping motor STM 1 .

A rotation length of the inclination surface 31 c from the inclination starting point 31 e of the inclination surface 31 c passing through the flat peak 31 b to an inclination ending point 31 f of the inclination surface 31 c is configured to be equivalent to 30 pulses of the rotation control signal of the stepping motor STM 1 .

A rotation length of the flat peak 31 b from the inclination ending point 31 f to the sharp wall 31 d is configured to be equivalent to 3 pulses of the rotation control signal of the stepping motor STM 1 . The 35 pulses of the rotation control signal of the stepping motor STM 1 correspond to one rotation round of the rotation transferring gear 23 which makes the reciprocating shaft 24 complete one reciprocation along Z axial direction.

As shown in FIG. 9 , the back surface of the base member 11 is provided with the spring retention plate 26 elongated toward the center of the CCD 101 which is configured to have a rear end portion 26 a fixed at one end of the reciprocating shaft 24 , a free end portion 26 b fixed by a taper-shaped retention pin 33 , and a protruding guide axis 26 c formed therebetween.

Position determining projections 11 a and 11 b , a coil attaching projection 11 c and an engaging projection 11 d are formed at the base member 11 . A recoiled portion 34 a of a torsion spring 34 is attached to the coil attaching projection 11 c , while one end portion 34 b of the torsion spring 34 is engaged with the engaging projection 11 d and the other end portion 34 c of the torsion spring 34 is engaged with the guide axis 26 c . A guide hole (not shown) to guide the guide axis 26 c is formed at the base member 11 .

While retaining a contact with the position determining projection 11 a , the spring retention plate 26 is made reciprocated by the torsion spring 34 for leaving from or approaching to the base member 11 along Z axial direction in accordance with the reciprocation of the reciprocating shaft 24 . The guide axis 26 c functions to stabilize the reciprocating movement of the spring retention plate 26 .

The retention pin 33 fulfills its function to retain mechanically the mount stage 15 at the zero point position by fitting itself to the recess portion 19 a . As shown in an enlarged view in FIG. 14A , a state in which a peripheral wall 33 a of the retention pin 33 is closely fitted to the recess portion 19 a of the protection plate 19 corresponds to a holding standby position of the cam pin 32 which is also the zero point position of the mount stage 15 . While another state in which the peripheral wall 33 a of the retention pin 33 is separated in the max distance to the recess portion 19 a of the protection plate 19 corresponds to a releasing standby position of the cam pin 32 as shown in an enlarged view in FIG. 14B .

6. Folding of the Flexible Base Plate

The flexible base plate 20 (Hereinafter referred to as a print base plate) includes a CCD connection section 201 , a coil connection section 202 , a position detecting element connection section 203 , a block circuit connection section 204 and a connection extension section 205 .

As shown in FIG. 15 , the CCD connection section 201 includes a connection pattern portion 201 a corresponding to connection pins of the CCD 101 and a penetrated hole 201 b corresponding to the recess portion 19 a of the protection plate 19 .

The coil connection section 202 is provided with a connection pattern portion for electrically connecting to each coil body of COL 1 , COL 1 ′, COL 2 and COL 2 ′ (which are not shown in FIGS. and hereinafter referred to as each coil body COL); and the position detecting element connection section 203 is also provided with a connection pattern portion for electrically connecting to the position detecting element 1252 . Thus, in the present embodiment, one end of the CCD connection section 201 which is connected by the photographing element CCD 101 functions as a photographing element connection section.

The block circuit connection section 204 includes a connection pattern portion 204 a for electrically connecting to the F/E IC 102 , the operational amplifier 1253 and the coil driver 1254 . As a result, a system block circuit may connect to the CCD connection section 201 , the coil connection section 202 and the position detecting element connection section 203 electrically via the connection extension section 205 . Thus, in the present embodiment, the other end of the block connection section 204 which is connected to the computation device, that is, the processor 104 and the F/E IC 102 , functions as an computation connection section.

In the present embodiment, the connection extension section 205 is configured to branch into a first connection extension portion 206 and a second connection extension portion 207 , both of which may overlap with each other if either of them is folded along a linear line a and another linear line b. The second connection extension portion 207 has a same configuration as that of the first connection extension portion 206 if two surfaces of the second connection extension portion 207 are reversed, thus, a description concerning the configuration of the second connection extension portion 207 will be omitted.

As shown in FIG. 16 , the first connection extension portion 206 includes a first linear part 208 , a first curving part 209 , a second linear part 210 , a second curving part 211 and a third linear part 212 with a same width.

When disposed, the first linear part 208 extends from the CCD connection section 201 disposed on the rear surface of the CCD 101 in a direction of an inclined angle of 45 degrees with respect to X and Y axes toward the corner portion 10 b . The first curving part 209 has in general a circular sector shape with a central angle of roughly 45 degrees and connects the first linear part 208 and the second linear part 210 therebetween. The second linear part 210 extends along X axial direction. The second curving part 211 has in general a circular sector shape with a central angle of roughly 90 degrees and connects the second linear part 210 and the third linear part 212 therebetween. The third linear part 212 is configured to have a length equal to that of the second linear part 210 and extend along a direction perpendicular to the second linear part 210 , in other words, along Y axial direction.

7. Fixation of the Flexible Base Plate

As shown in FIG. 16 , the print base plate 20 is fixed at the CCD stage 1251 from the protection plate 19 side by matching the connection pattern portion 201 a of the CCD connection section 201 with the connection pins of the CCD 101 and the penetrated hole 201 b with the recess portion 19 a , respectively.

A FPC auxiliary plate 213 is fixed at the print base plate 20 . The FPC auxiliary plate 213 is configured to match in shape with a part of the CCD connection section 201 , the first linear part 208 and the first curving part 209 of the first connection extension portion 206 , and to include a first edge portion 213 a along the linear line a, a second edge portion 213 b along a boundary line of the first curving part 209 and the second linear part 210 , and a third edge portion 213 c along a linear line d.

As shown in FIG. 17 , the second connection extension portion 207 is folded and overlapped over the first connection extension portion 206 so as to sandwich the FPC auxiliary plate 213 therebetween, using the linear line a and the linear line b as folding lines.

Using a linear line c as a folding line, the position detecting element connection section 203 is folded and overlapped over the CCD connection section 201 , and connected to the position detecting element 1252 electrically.

Using the linear line d as a folding line, the coil connection section 202 is folded and overlapped over the CCD connection section 201 , and connected to the each coil body COL electrically. According to this procedure, the print base plate 20 is fixed at the CCD stage 1251 and positioned at the XY plane on the base member 11 , as shown in FIG. 17 .

As shown in FIG. 9B , FIG. 11 , FIG. 18A and FIG. 18B , the second linear part 210 is folded close to a right angle through plastic deformation along a linear line e at the corner portion 10 b of the holding tube 10 so as to extend along an YZ plane.

Furthermore, the second curving part 211 is folded close to a right angle through plastic deformation along a linear line f so that the second curving part 211 extends along the holding tube 10 other than the second linear part 210 in an XY plane displaced from the base member 11 to the lens barrel side along Z axial direction.

The third linear part 212 is folded close to a right angle through plastic deformation along a linear line g at the corner portion 10 b of the holding tube 10 so as to extend along an XZ plane.

The block connection section 204 is folded close to a right angle through plastic deformation along a linear line h so as to extend along an XY plane outside the holding tube 10 . Through a back-folding portion 214 extending along the XZ plane which is formed by folding along the linear line h, the block circuit connection section 204 is fixed at the base member 11 (Referring to FIG. 7 and FIG. 9B ). Thus, the block circuit connection section 204 is fixed in the main body relative to the photographing optical axis.

Thus, the first linear part 208 and the first curving part 209 constitute a first extension section extending along the XY plane; the second linear part 210 constitutes a second extension section extending toward the subject viewing from the photographing element CCD 101 ; the second curving part 211 constitutes a third extension section extending along the XY plane; and the third linear part 212 constitutes a fourth extension section extending in a direction away from the subject viewing from the photographing element CCD 101 .

When the image-blur suppression is performed, the mount stage 15 is moved along the XY plane on the base member 11 . As a result, there rises on the print base plate 20 a variation on a relative distance between the mount stage connection side fixed to the mount stage 15 and the block circuit connection side fixed to the base member 11 . In order to prevent a deformation force resulted from the variation on the relative distance therebetween, the print base plate 20 is configured to have the second linear part 210 in the YZ plane, the third linear part 212 in the XZ plane, both of which are positioned perpendicular to each other.

Since the print base plate 20 deforms easily along its thickness direction, a deformation force resulted from the bending deformation of the second linear part 210 along X axial direction and a deformation force resulted from the bending deformation of the third linear part 212 along Y axial direction may be absorbed, as a result, the deformation force resulted from the variation on the relative distance in the XY plane may be absorbed.

Furthermore, when a deformation force which is resulted from a movement of the mount stage 15 is applied to the folding portion, that is the linear line e, between the mount stage connection side and the second linear part 210 , it becomes a distortional stress to make the second linear part 210 deforming to bend into a shape like a letter C toward one direction. Since the second curving part 211 is configured to be present in a XY plane enclosed by the second linear part 210 , the third linear part 212 and the holding tube 10 , thus the distortional stress may be alleviated to reduce its repulsive force, hence the deformation force resulted from the movement of the mount stage 15 may be effectively absorbed.

A same thing will happen to the third linear part 212 which absorbs a deformation force along Y axial direction.

As a result, the print base plate 20 will not hinder the mount stage 15 from moving along the XY plane when the image-blur suppression is performed.

Since the print base plate 20 is folded at the corner portion 10 b of the holding tube 10 along Z axial direction, it is possible to utilize a peripheral space of the lens barrel which has a circular configuration in general, that is the corner portion 10 b of the holding tube 10 , and thus to prevent the camera from growing bigger in size.

Since the print base plate 20 is provided with the connection extension section 205 branched into the first connection extension portion 206 and the second connection extension portion 207 which may be folded and overlapped, it is possible to increase an electrical transmission path without increasing a width of the connection extension section 205 and it is also possible to hold the print base plate 20 in a limited space of the corner portion 10 b of the holding tube 10 . Therefore, it is not necessary to provide the second connection extension portion 207 if electrical transmission paths are limited.

Since the print base plate 20 is fixed with the FPC auxiliary plate 213 , there will be no bending deformations occurred on the print base plate 20 from the CCD connection section 201 through the first linear part 208 up to the first curving part 209 , and the deformation force resulted from the movement of the mount stage 15 may be transferred to act on the third linear part 212 , therefore, it is certain for the deformation force to be absorbed effectively.

8. Zero Point Retention Control Circuit of the Image-blur Suppression Mechanism

The stepping motor STM 1 is controlled by the zero point retention control circuit shown in FIG. 19 through a two-phase configuration. Each of terminals of a first coil STMC′ is connected to a motor driver MD 3 which is a part of the driver 1261 through output lines 40 a and 40 a ′, respectively. Each of terminals of a second coil STMC″ is connected to the motor driver MD 3 through output lines 40 b and 40 b ′, respectively. Resistance R 18 and R 19 for limiting a currency are inter-positioned in the output lines 40 a and 40 b , respectively. A condenser C 7 and a condenser C 8 are inter-positioned between the output lines 40 a and 40 a ′, 40 b and 40 b ′, respectively.

The motor driver MD 3 not only receives retention control signals ports IN 1 and IN 2 of the processor 104 but also receives enable signals from a port ENA of the processor 104 , and based on the received signals, the motor driver MD 3 performs a power control to the stepping motor STM 1 .

A flow chart is shown in FIG. 20 to explain an operation of the zero point retention control circuit including a three-step processing operation: a reset processing, a release processing and a retention processing.

In step S 1 , after the power switch SW 13 of the digital camera is set on, the reset processing is performed at first controlled by the processor 104 to drive the stepping motor STM 1 to rotate 2 pulses in a counter clockwise direction at a slow speed of 200 pps (pulse per second), then drive it to rotate 33 pulses in the counter clockwise direction at a fast speed of 1000 pps and finally drive it to rotate 2 pulses in a clockwise direction at a slow speed of 200 pps.

The cam pin 32 may contact physically the sharp wall 31 d of the cam groove 31 if the stepping motor STM 1 is rotated 35 pulses in the counter clockwise direction wherever the cam pin 32 is in the rotation direction of the cam groove 31 .

After the stepping motor STM 1 is rotated 2 pulses in the clockwise direction from the contact position, the cam pin 32 is set at the inclination starting position 31 e of the cam groove 31 (Referring to FIG. 13E ), which corresponds to the state that CCD 101 is retained at the zero point O. The zero point O is also the central point of a movable range of the mount stage 15 . About 53 milliseconds are needed from setting the power on to finishing the reset.

In the present embodiment, the image-blur suppression mechanism is configured to perform the image-blur suppression after the image-blur suppression switch SW 14 is set on and discharge the image-blur suppression after the image-blur suppression switch SW 14 is turned off or after the photographing is finished.

In step S 2 , after the image-blur suppression switch SW 14 is set on, the release processing is performed controlled by the processor 104 to drive the stepping motor STM 1 to rotate 2 pulses in the clockwise direction at a slow speed of 200 pps and 28 pulses in the clockwise direction at a fast speed of 1000 pps, and then the power to the stepping motor STM 1 is shut down after maintained for 5 milliseconds.

The cam pin 32 is positioned at the inclination ending position 31 f of the cam groove 31 by the release processing (Referring to FIG. 13D ). About 43 milliseconds are needed to move the cam pin 32 from the inclination starting position 32 e to the inclination ending position 32 f . In other words, it takes about 43 milliseconds to move the cam pin 32 from the holding standby position to the releasing standby position at which the image-blur suppression is performed.

In step S 3 , after the image-blur suppression switch SW 14 is set off or the photographing is performed, the retention processing is performed by the processor 104 to drive the stepping motor STM 1 to rotate 2 pulses in the clockwise direction at a slow speed of 200 pps (pulse per second) and 3 pulses in the clockwise direction at a fast speed of 1000 pps. As a result, the cam pin 32 contacts the flat valley floor 31 a by passing the flat peak 31 b of the cam groove 31 and falling down to the flat valley floor 31 a . Then the power to the stepping motor STM 1 is shut down after maintained for 5 milliseconds.

The cam pin 32 is positioned at the inclination starting position 31 e of the cam groove 31 and the CCD 101 is retained at the central position by the retention processing. When the power is kept on, once after the reset processing is performed, there are performed the release processing and retention processing. It takes about 18 milliseconds to move the cam pin 32 from the releasing standby position to the retention standby position.

According to the image-blur suppression mechanism, the CCD 101 is retained forcibly at the central position of the mount stage 15 by the retention pin 33 formed at the spring retention plate 26 , it is expected to decrease a power consumption of the image-blur suppression mechanism even if it is in operation since there is no need to continue supplying a power in order to retain the CCD 101 at the zero point position of the mount stage 15 .

9. Configuration of a Detection Circuit of the Image-blur Suppression Mechanism

As shown in FIG. 21 , the detection circuit of the image-blur suppression mechanism includes an X axial direction rotation detecting section to detect a rotation of X axial direction, and a Y axial direction rotation detecting section to detect a rotation of Y axial direction.

The X axial direction rotation detecting section includes for example a piezoelectric vibration gyro-sensor S 1 B of which a first terminal is earthed via a condenser C 13 , a second terminal is connected to a plus terminal of an operational amplifier OP 3 via a condenser C 10 provided at a position in a connection line 42 , a third terminal is connected to a minus terminal of the operational amplifier OP 3 via a resistance R 23 provided at a position in a connection line 43 , and a fourth terminal is connected to the connection line 43 via a condenser 11 while being earthed.

The plus terminal of the operational amplifier OP 3 is connected to the connection line 43 via a resistance R 20 . The resistance R 20 and a series body consisting of the resistance R 20 and an alternative switch ASW 1 are connected in parallel with each other between the connection lines 42 and 43 .

An output terminal of the OP 3 is connected to the minus terminal of the OP 3 via a condenser C 12 . A resistance R 22 is provided in parallel with the condenser C 12 . The condenser C 10 and the resistance R 20 make up a high-pass filter HPF 1 and the condenser C 12 and the resistance R 22 constitute a low-pass filter LPF 1 . The operational amplifier OP 3 amplifies an output from the piezoelectric vibration gyro-sensor S 1 B and output it from the output terminal of the OP 3 as an X axial direction rotation detecting signal OUT 1 .

The Y axial direction rotation detecting section includes for example a piezoelectric vibration gyro-sensor S 2 A of which a first terminal is earthed via a condenser C 17 , a second terminal is connected to a plus terminal of an operational amplifier OP 4 via a condenser C 17 provided at a position in a connection line 44 , a third terminal is connected to a minus terminal of the operational amplifier OP 4 via a resistance R 26 provided at a position in a connection line 45 , and a fourth terminal is connected to the connection line 45 via a condenser 15 while being earthed.

The plus terminal of the operational amplifier OP 4 is connected to the connection line 45 via a resistance R 24 . The resistance R 20 and a series body consisting of the resistance R 20 and an alternative switch ASW 2 are connected in parallel with each other between the connection lines 44 and 45 .

An output terminal of the OP 4 is connected to the minus terminal of the OP 4 via a condenser C 16 . A resistance R 27 is provided in parallel with the condenser C 16 . The condenser C 14 and the resistance R 24 make up a high-pass filter HPF 2 and the condenser C 16 and the resistance R 27 constitute a low-pass filter LPF 2 . The operational amplifier OP 4 amplifies an output from the piezoelectric vibration gyro-sensor S 2 A and output it from the output terminal of the OP 4 as a Y axial direction rotation detecting signal OUT 2 .

An alternative switch controlling signal SWC 1 is output to the alternative switches ASW 1 and ASW 2 via a signal line 46 . The alternative switches ASW 1 and ASW 2 have a function to speed charge the condensers C 11 and C 15 in order to speed up response speeds of the high-pass filters HPF 1 and HPF 2 , respectively. The processor 104 outputs the alternative switch controlling signal SWC 1 to the alternative switches ASW 1 and ASW 2 at a given time after the power is set on to initialize the alternative switches ASW 1 and ASW 2 . The detecting signals OUT 1 and OUT 2 from the respective gyro-sensors S 1 B and S 2 A are retrieved by the A/D converter 10411 every T seconds. Thus, θ yaw (t) and θ pitch (t) may be obtained from equations in the follows:

θ yaw( t )=Σω yaw( i )× T

θ pitch( t )=Σω pitch( i )× T

wherein

θ yaw (t): angular variation in YAW direction;

θ pitch (t): angular variation in PITCH direction;

ω yaw (t): instant angular velocity in YAW direction; and

ω pitch (t): instant angular velocity in PITCH direction.

A focus length f is determined from a zoom point zp and a focus point fp. Thus, D yaw (t), D pitch (t), θ yaw (t) and θ pitch (t) meet equations listed in the follows:

D yaw( t )= f ×tan (θ yaw ( t ))  (i)

D pitch( t )= f ×tan (θ pitch ( t ))  (ii)

wherein

D yaw (t): displacement amount of an image along X axial direction corresponding to rotation in YAW direction; and

D pitch (t): displacement amount of an image along Y axial direction corresponding to a rotation in PITCH direction.

In other words, D yaw (t) and D pitch (t) correspond to a displacement amount of the CCD 101 which should be moved along Y axial direction.

When there are rotation displacements along YAW and PITCH directions occurred from the camera shake, a target position of the CCD 101 is calculated according to equations (i) and (ii), and the mount stage 15 is driven to move so that a difference between a real position of the CCD 101 along the X and Y axial directions detected by the position detecting element 1252 and the target position of the CCD 101 becomes zero. This control is performed every T seconds.

Furthermore, when the detected outputs from the gyro-sensors S 1 B and S 2 A are of a value of zero, the mount stage 15 is controlled so that the CCD 101 is translated so as to follow a translation displacement Xd of the camera main body.

10. Control Circuit of the Image-blur Suppression Mechanism

As shown in FIG. 22 , the control circuit of the image-blur suppression mechanism includes a feedback circuit 50 and a position-voltage setting circuit 51 .

Hall elements H 1 and H 2 constitute a part of the position-voltage setting circuit 51 . A predefined voltage Vh 1 − is applied to the hall element H 1 ( 1252 a ). One terminal of the hall element H 1 is connected to a minus terminal of an operational amplifier OP 1 via a resistance R 2 and the other terminal is connected to a plus terminal of the operational amplifier OP 1 via a resistance R 3 .

An output terminal of the operational amplifier OP 1 is connected to an input port L 1 of the processor 104 via a resistance R 5 and to the minus terminal of itself via a resistance R 1 . In addition, a connection point of the resistance R 5 and the output port L 1 is earthed via a condenser C 1 .

A predefined voltage Vh 2 − is applied to the hall element H 2 ( 1252 b ). One terminal of the hall element H 2 is connected to a minus terminal of an operational amplifier OP 2 via a resistance R 7 and the other terminal is connected to a plus terminal of the operational amplifier OP 2 via a resistance R 3 .

An output terminal of the operational amplifier OP 2 is connected to an input port L 2 of the processor 104 via a resistance R 9 and to the minus terminal of itself via a resistance R 6 . In addition, a connection point of the resistance R 9 and the output port L 2 is earthed via a condenser C 2 .

An output port L 3 of the processor 104 is connected to a D/A converter circuit IC 2 included in the position-voltage setting circuit 51 and output ports L 4 and L 6 are connected to both the D/A converter circuit IC 1 and the D/A converter circuit IC 2 . An output port L 5 is connected to the D/A converter circuit IC 1 .

Two output lines 61 and 62 are connected to the D/A converter circuit IC 2 among which the output line 61 is connected to the plus terminal of the operational amplifier OP 1 through a resistance R 4 and the other line 62 is connected to the plus terminal of the operational amplifier OP 2 through a resistance R 10 .

A chip selector signal DI from the output port L 3 , a clock signal SCLK from the output port L 4 and a compensation digital data DIN from the output port L 6 are input to the D/A converter circuit IC 2 which has a function to convert the compensation digital data from digital to analogue.

The D/A converter circuit IC 1 is configured as a part of the feedback circuit 50 . A common line 63 and two output lines 64 and 65 are connected to the D/A converter circuit IC 1 . The common line 63 is connected to the coil drives MD 1 and MD 2 . The output line 64 is connected to an input terminal L 7 of the coil drive MD 1 through a resistance R 14 and the output line 65 is connected to an input terminal L 8 of the coil drive MD 2 through a resistance R 15 .

A connection point of the resistance R 14 and the input terminal L 7 is connected to an earth terminal ER 1 of the coil drive MD 1 through a condenser C 3 and a connection point of the resistance R 15 and the input terminal L 8 is connected to an earth terminal ER 2 of the coil drive MD 2 through a condenser C 4 . The common line 63 is connected to a power Vcc through series resistances R 12 and R 11 , and is earthed through a resistance R 13 at a connection point between the common line 63 and the resistance R 12 .

A control signal CONT 1 from the processor 104 is input to both the coil drives MD 1 and MD 2 . Output terminals of the coil drive MD 1 are connected with a series body including a resistance R 16 and a series coil body COL 1 ″ having the coil bodies COLL and COL 1 ′ in series, in parallel to the series body a condenser C 5 is connected.

Similarly, output terminals of the coil drive MD 2 are connected with a series body including a resistance R 17 and a series coil body COL 2 ″ having the coil bodies COL 2 and COL 2 ′ in series, in parallel to the series body a condenser C 6 is connected.

The series coil bodies COL 1 ″ and COL 2 ″ are configured to drive the mount stage 15 along X axial direction and Y axial direction, respectively.

Predefined voltages Vh 1 − and Vh 2 + are applied to the hall elements H 1 and H 2 , respectively. When the detected outputs from the gyro-sensors S 1 B and S 2 A are of a value of zero and when the CCD 101 is in the central position (zero point) of the movable range, detected output voltages for the hall elements H 1 and H 2 are configured to be Vh 1 and Vh 2 , respectively, and analogue output voltages for the input ports L 1 and L 2 of the processor 104 to be V 1 ADin and V 2 ADin, respectively. The output voltages V 1 ADin and V 2 ADin are practically measured.

The practically measured output voltages V 1 ADin and V 2 ADin vary in relation to assembly errors concerning such as mechanical positions between the permanent magnets 16 a to 16 d and the hall elements H 1 and H 2 , and attached positions between the hall elements H 1 and H 2 with respect to the mount stage 15 and the series bodies COL 1 ″ and COL 2 ″. In addition, the hall elements H 1 and H 2 vary characteristically themselves.

Therefore, if some kind of compensation is not performed, detected values of the hall elements H 1 and H 2 with respect to the zero point would be different in each camera, and this may bring to a problem that it is impossible to carry out an accurate image-blur suppression.

Thus, compensation voltages Vr 1 ′ and Vr 2 ′, which are input to operational amplifiers OP 1 and OP 2 respectively from the D/A converter IC 2 , are set to compensate variations on the output voltages V 1 ADin and V 2 ADin, which are practically measured when the series bodies COL 1 ″ and COL 2 ″ are not powered to control the CCD 101 positioned at the zero point, so that they have set standard voltage values.

In order to set a roughly center value, for example 1.7 volts, of an operational voltage range for the operational amplifiers OP 1 and OP 2 as the set standard voltage value, the processor 104 performs computations described in the follows.

In the present embodiment, the resistances are set but not limited to meet the following conditions for convenience: R 2 =R 3 =R 7 =R 8 , R 1 =R 4 =R 6 =RIO.

If R 2 =R 3 =R 7 =R 8 , R 1 =R 4 =R 6 =R 10 , then V 1 ADin and V 2 ADin meet equations:

V 1 AD in=R1 /R 2×(( Vh 1+)−( Vh 1−))+ Vr 1′

V 2 AD in=R1 /R 2×(( Vh 2+)−( Vh 2−))+ Vr 2′

The processor 104 acquires the compensation voltages Vr 1 ′ and Vr 2 ′ by performing a computation based on the above mentioned equations. As a result, the detected values of the hall elements H 1 and H 2 with respect to the zero point may vary in relation to assembly errors concerning such as mechanical positions between the permanent magnets 16 a to 16 d and the hall elements H 1 and H 2 , and attached positions between the hall elements H 1 and H 2 with respect to the mount stage 15 and the series bodies COL 1 ″ and COL 2 ″ but constantly.

The processor 104 , together with the D/A converter circuit IC 2 , constitute a part of the compensation circuit which outputs a compensation value in order to set the detected values of the hall elements H 1 and H 2 as the set standard voltage values no matter how the detected values may vary. In addition, the processor 104 functions as a computation device to obtain compensation values by performing a computation on the set standard voltage values.

As shown in a flow chart including steps S 1 to S 3 in FIG. 23 , an initial setting for the image-blur suppression control is performed at a final stage in a camera assembly factory before factory shipment.

The actual control is shown in FIG. 24 . The processor 104 retrieves a controlling target value which is computed from the detecting output signals OUT 1 and OUT 2 from the detection circuit of the image-blur suppression mechanism (Step S 11 ), then retrieves the real output voltages V 1 ADin and V 2 ADin corresponding to actual positions obtained from the hall elements H 1 and H 2 , respectively (Step S 12 ), and a difference value is computed by the processor 104 between the above two (Step S 13 ).

Based on the difference value, the processor 104 outputs the control data to the D/A converter circuit IC 1 which outputs control voltages Vdac 1 and Vdac 2 (Step S 14 ). The control voltages Vdac 1 and Vdac 2 are input to the coil drives MD 1 and MD 2 which output driving voltages Vout 1 and Vout 2 to the series coil bodies COL 1 ″ and COL 2 ″, respectively.

The driving voltages Vout 1 and Vout 2 are determined according to the following equations:

V out1=( Vdac 1 −Vr )× K

V out2=( Vdac 2 −Vr )× K

wherein, Vr is a division voltage and K is a ratio constant based on the division voltage Vr.

The CCD 101 is attracted or repelled by the permanent magnets of 16 a to 16 d and the series coil bodies COL 1 ″ and COL 2 ″ to move in a direction determined by that whether the driving voltages Vout 1 and Vout 2 are of positive or negative voltages. The detecting values of the hall elements H 1 and H 2 vary accordingly. Though the real output voltages V 1 ADin and V 2 ADin may vary according to the variations of the detecting values of the hall elements H 1 and H 2 , they are fed back to the processor 104 , thus it is possible to make the CCD 101 follow a target position instantly even though the control target value based on the detecting output voltages from the detection circuit of the image-blur suppression varies (Step S 15 ). The control is finished when the photographing has been performed (Step S 16 ).

A variant example of the feedback circuit 50 is shown in FIG. 25 . In this variant example, the processor 104 controls a coil driver MD 4 according to a PWM control to perform the power control to the series coil bodies COL 1 ″ and COL 2 ″.

In other words, pulse voltages Vin 1 and Vin 2 are input to the coil driver MD 4 together with a positive direction signal CON 1 and a negative direction signal CON 2 . The voltages applied to the series coil bodies COL 1 ″ and COL 2 ″ are proportional to a lasting time duration of high level pulse signals of the pulse voltages Vin 1 and Vin 2 .

11. Photographing Detail when the Image-blur Suppression Mechanism is on

As shown in FIG. 26 , when the image-blur suppression switch SW 14 is set on in step S 1 , the gyro sensors S 1 A and S 2 A are powered on (Step S 2 ). After the release switch SW 1 is half pressed, an auto focus operation is initialized in step S 3 . Simultaneously, a forcible mechanical fixation of the mount stage 15 is released and a retention control of the CCD 101 at the zero point is initialized when the series coil bodies COL 1 ″ and COL 2 ″ are powered on in step S 4 .

Then a monitor processing is initialized to monitor the camera shake in step S 5 . In step S 6 , the processor 104 determines whether the half press of the release switch SW 1 is ongoing. The procedure returns back to step S 3 if the half press of the release switch SW 1 is released. If the half press of the release switch SW 1 is ongoing, the processor 104 determines whether the release switch SW 1 is fully pressed in step S 7 . If the release switch SW 1 is not fully pressed, the procedure returns back to step S 6 .

After the release switch SW 1 is fully pressed, the image-blur suppression mechanism controls the CCD 101 to follow a movement of the subject image in step S 8 and an exposure is performed in step S 9 . When the exposure is finished in step S 10 , the CCD 101 is stopped to follow the subject image and the mount stage 15 is returned back to the zero point position according to the power control on the series coil bodies COL 1 ″ and COL 2 ″ in step S 11 . Whether the mount stage 15 is returned back to the zero point position is determined in step S 12 and the mount stage 15 is fixed at the zero point position forcibly after it is determined to have returned back to the zero point position in step S 13 .

There are two modes for the operation timing of the release switch SW 1 .

FIG. 27 is a timing chart of a compensation procedure for the image-blur suppression mechanism when the release switch SW 1 is half and fully pressed in a two-stage press procedure.

Herein the two-stage press procedure refers to a discontinuous release operation between an operation when the release switch SW 1 is half pressed and an operation when the release switch SW 1 is fully pressed. For example, a photographing operation in which a chance is taken to press fully the release switch SW 1 for an exposure while the release switch SW 1 is being half pressed.

When the release switch SW 1 is half pressed, the digital camera starts a focus operation. In this state, the zero point retention mechanism 1263 still keep the mount stage 15 fixed at the zero point position and the series coil bodies COL 1 ″ and COL 2 ″ are not powered on. The subject image is displayed on the LCD monitor 10 in this state.

As soon as the focus operation is finished, the processor 104 starts to power the stepping motor STM 1 of the zero point retention mechanism 1263 and accordingly the forcible mechanical fixation of the mount stage 15 is released. At the same time, the series coil bodies COL 1 ″ and COL 2 ″ are powered on. And thus the image-blur suppression is performed when the release switch SW 1 is half pressed (Release 1 ). After the release switch SW 1 is fully pressed (Release 2 ), the mount stage 15 is returned once back to the central position according the power control on the series coil bodies COL 1 ″ and COL 2 ″, the LCD monitor 10 is powered off after some time.

The mount stage 15 is controlled to follow the movements of the subject image resulted from the camera shake while the image is being exposed. As soon as the image exposure is finished the mount stage 15 is returned back to the central position according to the power control on the series coil bodies COL 1 ″ and COL 2 ″, and then the processor 104 begins to power the stepping motor STM 1 of the zero point retention mechanism 1263 and accordingly the mount stage 15 is mechanically and forcibly fixed. After that, the power applied to the series coil bodies COL 1 ″ and COL 2 ″ is stopped.

Since the image-blur suppression is performed in release 1 , thus even though there is a camera shake to the camera, it is possible for a user to view the subject image without image blurring on the LCD monitor 10 .

The subject image may be constructed in the release 2 with a deviation to that in the release 1 when the mount stage 15 is returned once to the central position in the release 2 ; since it is possible to confirm the subject image just before photographed when the mount stage 15 is returned once to the central position in the release 2 according to the present embodiment, thus, it is possible to conform the subject image construction before the subject image is photographed or exposed.

As shown in FIG. 28 , in a case when the release switch SW 1 is half pressed and then released without being fully pressed, simultaneous to the half press of the release switch SW 1 , the focus operation is initialized.

As soon as the focus operation is finished, the processor 104 starts to power the stepping motor STM 1 of the zero point retention mechanism 1263 and accordingly the forcible mechanical fixation of the mount stage 15 is released. At the same time, the series coil bodies COL 1 ″ and COL 2 ″ are powered on, thus the image-blur suppression is performed when the release switch SW 1 is half pressed (Release 1 ).

When the release switch SW 1 is released while it's being half pressed, the mount stage 15 is returned to the central position according to the power control on the series coil bodies COL 1 ″ and COL 2 ″, and then the processor 104 starts to power the stepping motor STM 1 of the zero point retention mechanism 1263 and accordingly the mount stage 15 is mechanically and forcibly fixed. After that, the power applied to the series coil bodies COL 1 ″ and COL 2 ″ is stopped.

FIG. 29 is a timing chart explaining the compensation procedure of the image-blur suppression mechanism when the release switch is fully pressed at a burst.

Herein the full press at a burst refers to a continuous release operation between an operation when the release switch SW 1 is half pressed (Release 1 ) and an operation when the release switch SW 1 is fully pressed (Release 2 ). For example, a photographing operation in which a chance is taken to press fully a release switch for an exposure while the release switch is being half pressed. For example, a photographing operation in which the release switch SW 1 is pressed fully for an exposure right after it is half pressed.

When the release switch SW 1 is half pressed, the focus operation of the digital camera is initialized and the LCD monitor 10 is set to a state for displaying the subject image. And when the release switch SW 1 is pressed fully right after it is half pressed, the LCD monitor 10 is powered off at the same time.

After the focus operation is finished, the processor 104 starts to power the stepping motor STM 1 of the zero point retention mechanism 1263 and accordingly the forcible mechanical fixation of the mount stage 15 is released. At the same time, the series coil bodies COL 1 ″ and COL 2 ″ are powered on, and the mount stage 15 is returned to the central position according to the power control on the series coil bodies COL 1 ″ and COL 2 ″. Accordingly, the image-blur suppression is performed.

In other words, the mount stage 15 is controlled to follow the movements of the subject image resulted from the camera shake while the central position maintenance of the mount stage 15 is being performed according to the power control on the series coil bodies COL 1 ″ and COL 2 ″ and the exposure on the subject image is being initialized. As soon as the exposure on the subject image is finished, the mount stage 15 is returned back to the central position according to the power control on the series coil bodies COL 1 ″ and COL 2 ″, and then the processor 104 starts to power the stepping motor STM 1 of the zero point retention mechanism 1263 and accordingly the mount stage 15 is mechanically and forcibly fixed. After that, the power applied to the series coil bodies COL 1 ″ and COL 2 ″ is stopped.

In the case when the release switch SW 1 is fully pressed at a burst, there is no need to confirm the subject image construction in the release 2 since it is presumed that it has been done in the release 1 , and in addition it is considered that there is no need to confirm the subject image construction even after the mount stage 15 is returned back to the central position once in the release 2 , thus, it is expected to simplify the image-blur suppression procedure.

Furthermore, since the LCD monitor 10 is powered off in the focus operation, it is possible to avoid unnecessary battery consumption.

In addition, as shown in FIG. 9A , when the mount stage 15 is forcibly pressed to the zero point position mechanically, it is possible to prevent the mount stage 15 from guttering along Z axial direction since the adsorption bar 35 is maintained to the permanent magnets 16 b and 16 d through adsorption force. Furthermore, even though the mount stage 15 is not at the zero point position, it may still be maintained the permanent magnets 16 b and 16 d through adsorption force, thus, the gutter of the mount stage 15 along Z axial direction may also be prevented.

Although the present invention has been explained in relation to its preferred embodiments and drawings but not limited, it is to be understood that other possible modifications and variations made without departing from the spirit and scope of the invention will be comprised in the present invention. Therefore, the appended claims encompass all such changes and modifications as falling within the true spirit and scope of this invention.