Electrical device, control method, and program

This application is a U.S. national stage application of PCT/JP2011/051253 filed on Jan. 24, 2011, and is based on Japanese Patent Application No. 2010-183088 filed on Aug. 18, 2010, the disclosure of which is incorporated herein by reference.

The present invention relates to an electrical device, such as a hand-held remote controller, a control method, and a program.

A household electrical appliance such as an air conditioner or a television is provided with a remote controller, as an accessory, for remotely operating the household electrical appliance. A remote controller generally includes a liquid crystal display (LCD) and a backlight to display a temperature and humidity if the remote controller is for an air conditioner, for example.

In a conventional remote controller, if the temperature and humidity are always displayed, the battery power is wasted and the frequency of battery replacement and charge increases, increasing the work burden on the user.

Given that, a remote controller with a vibration sensor is disclosed (see, for example, Patent Literature 1). In this remote controller, once the vibration sensor detects a vibration caused by a user holding the remote controller in his/her hand, the LCD display is turned on, and then once a predetermined amount of time has passed after the user completes his/her operation, the LCD display is turned off. This reduces power consumed by the remote controller. Since the LCD display is turned on immediately after the vibration sensor detects that a user is holding the remote controller in his/her hand, operability is not impaired.

Meanwhile, a mobile terminal device that can differentiate the vibration caused by a user's running and walking and a dropping of the mobile terminal device is disclosed (see, for example, Patent Literature 2).

Patent Literature

Patent Literature 1: Unexamined Japanese Patent Application Kokai Publication No. H10-304480

Patent Literature 2: Unexamined Japanese Patent Application Kokai Publication No. 2007-101406

However, in the remote controller disclosed in Patent Literature 1, the vibration sensor may falsely detect, for example, an impact that occurs when the remote controller hits against a floor or the like caused by an operation of the user. This false detection turns on the LCD display, which wastes power.

In the mobile terminal device disclosed in Patent Literature 2, dropping of the mobile terminal device and a vibration caused by a user's walking and running can be differentiated, but it is difficult to differentiate the vibration that occurs when a user holds the mobile terminal device in his/her hand and the vibration caused by the impact of dropping the mobile terminal device.

The present invention was made in view of the above circumstances and has an objective of providing an electrical device that can further reduce power consumption, a control method, and a program.

In order to achieve the above objective, the present invention provides an electrical device that a user uses in his/her hand. In this electrical device, an acceleration sensor detects an acceleration, a timer measures elapsed time, a calculator calculates an index value regarding movement of the electrical device on the basis of an acceleration detected by the acceleration sensor, a determiner determines whether the user is holding the electrical device in his/her hand on the basis of the change of an index value that is obtained from the index value calculated by the calculator and an amount of time measured by the timer, and an operation controller cancels the sleep state of the electrical device if the determiner determines that the user is holding the electrical device in his/her hand.

According to the present invention, if it is determined that the user is holding the electrical device in his/her hand on the basis of change of an index value regarding movement of the electrical device obtained from an acceleration detected by the acceleration sensor, or the like, the sleep state of the electrical device is canceled. This prevents the sleep state of the electrical device from being canceled for movement of the electrical device that occurs due to a different factor, such as a collision, thereby further reducing power consumption.

FIG. 1 is a block diagram illustrating a configuration of a remote controller according to an embodiment of the present invention;

FIG. 2 is a graph illustrating one example of jerk over time when a user lifts a remote controller;

FIG. 3 is a graph illustrating one example of jerk over time when a remote controller hits against a floor;

FIG. 4 is a graph illustrating one example of jerk over time when a minute vibration is applied to a remote controller;

FIG. 5 is a graph illustrating one example of jerk over time where a minute vibration is applied to a remote controller;

FIG. 6 is a flow chart of an entire processing of a controller of a remote controller;

FIG. 7 is a flow chart of an operation processing subroutine;

FIG. 8 is a flow chart of a standby processing subroutine;

FIG. 9 is a flow chart of a factor determination processing subroutine; and

FIG. 10 is a block diagram illustrating another configuration of the remote controller in FIG. 1 .

An embodiment of the present invention will be described in detail with reference to drawings.

(Configuration of Remote Controller)

FIG. 1 illustrates a configuration of a remote controller 1 according to an embodiment of the present invention. This remote controller 1 is an electrical device that a user generally uses in his/her hand. As illustrated in FIG. 1 , the remote controller 1 includes an operating portion 2 , an acceleration sensor 3 , a transmitter 4 , a display 5 , a timer 6 , a memory 7 and a controller 10 .

The operating portion 2 is operated by the user and the user enters an operation input and then the operating portion 2 outputs an operation input signal corresponding to the entered operation input to the controller 10 .

The acceleration sensor 3 detects an acceleration that occurs in the remote controller 1 . The detected acceleration is output to the controller 10 . The acceleration sensor 3 is preferably disposed at a predetermined distance (the farthest, if possible) from a gripper (not illustrated) of a housing that is gripped by the user's hand. Since the swing of the remote controller 1 is greater at a portion that is farther from the user's hand, the acceleration sensor 3 can detect a greater acceleration. The greater an acceleration detected by the acceleration sensor 3 becomes, the higher the calculation accuracy of the jerk J becomes, which will be described later.

The transmitter 4 transmits the operation signal (for example, an infrared signal) that corresponds to the operation input from the user and is output from the controller 10 externally. This signal is received by an appliance to be operated by the user, and the appliance operates according to the received signal.

The display 5 is a display provided with an LCD and a backlight. The display 5 displays information to be shown to the user under the control of the controller 10 .

The timer 6 measures time under the control of the controller 10 .

The memory 7 stores information displayed on the display 5 under the control of the controller 10 .

The controller 10 integrally controls the above components of the remote controller 1 . The controller 10 includes a central processing unit (CPU) and a memory (both are not illustrated). By the CPU's execution of a program stored in the memory, functions of the following components composing the controller 10 are implemented.

The controller 10 includes an operation control means 11 , a calculation means 12 , a factor determination means 13 and a sleep control means 14 .

The operation control means 11 outputs an operation signal corresponding to an operation input signal entered from the operating portion 2 to the transmitter 4 . The transmitter 4 transmits the operation signal externally.

The calculation means 12 calculates a rate of change of the acceleration (jerk J) that occurs in the remote controller 1 , as an index value regarding movement of the remote controller 1 , on the basis of the acceleration detected by the acceleration sensor 3 .

A jerk J can be found from the difference between an acceleration detected by the acceleration sensor 3 and an acceleration detected by the acceleration sensor 3 at the previous sampling time, for example. In this embodiment, a jerk J is represented by an absolute value. That is because the same sign is used for threshold values that will be described later. If the threshold values are defined as positive and negative values, the jerk J does not need to be transformed to an absolute value.

The factor determination means 13 specifies a factor to change a jerk J on the basis of change of the jerk J that is obtained from the jerk J detected by the calculation means 12 and an amount of time measured by the timer 6 . Factors to change the jerk J include a lifting of the remote controller 1 by the user, a collision of the remote controller 1 by being dropped, and a minute vibration (for example, vibration caused by a human's walking) of the remote controller 1 .

Where a factor to change a jerk J is a lifting of the remote controller 1 by the user, the jerk J generally increases at the moment of lifting the remote controller 1 , and increases again at the moment when movement of the remote controller 1 stops after the lifting (an acceleration greatly decreases). The amount of time between the lifting and the stoppage of movement of the remote controller 1 is about 100 milliseconds even if the remote controller 1 is quickly moved.

Similarly, when the remote controller 1 is placed on a desk or falls onto the floor, a great acceleration occurs in the remote controller 1 . For example, when the remote controller 1 is placed on a desk, an acceleration of about 10 to 20 G (1G=9.8 m/s 2 ) occurs. When the remote controller 1 falls onto the floor, an acceleration of no less than several thousand G may occur. However, the amount of time of collision is for an instant, and the amount of time during which the jerk J greatly changes is shorter than the amount of time of lifting of the remote controller 1 .

The factor determination means 13 determines whether the factor to change the jerk J is a lifting of the remote by the user, on the basis of such characteristics as the change of the jerk J. For this determination, as threshold values of the jerk J, two threshold values Th 1 and Th 2 are used as a first threshold value and a second threshold value, respectively.

The threshold value Th 1 is a threshold value for detecting a jerk J at two timings: a moment when the remote controller 1 is lifted and a moment when movement of the remote controller 1 is stopped. If the jerk J exceeds the threshold value Th 1 , the remote controller 1 is moving due to some factor.

The threshold value Th 2 is a threshold value for detecting a jerk J that occurs when the remote controller 1 hits against something. The threshold value Th 2 is greater than the threshold value Th 1 .

In this embodiment, in order to determine the factors that change a jerk J of the remote controller 1 , a time threshold value as a first period (Time 1 ), a time threshold value as a second period (Time 2 ), and a time threshold value as a third period (Time 3 ) are used.

The time threshold value Time 1 is a threshold value regarding an amount of time between the moment when the user lifts the remote controller 1 and the moment when movement of the remote controller 1 is stopped after the lifting. If the jerk J first exceeds the threshold value Th 1 , then decreases to less than the threshold value Th 1 and remains without exceeding the threshold value Th 1 again while the amount of time after the jerk J first exceeds the threshold value Th 1 exceeds the time threshold value T 1 , the factor determination means 13 determines that the factor that changes the jerk J is not a lifting of the remote controller 1 by the user. In this embodiment the time threshold value Time 1 is three seconds, but the time threshold value Time 1 is not limited to three seconds.

The time threshold value Time 2 is a threshold value for differentiating a change of jerk J due to a lifting by the user and a change of jerk J due to a collision. The time threshold value Time 2 is shorter than the time threshold value Time 1 . The time threshold value Time 2 is decided on the basis of an amount of time of change of a jerk J that occurs when the remote controller 1 hits against something. In this embodiment, the time threshold value Time 2 is 50 milliseconds, but the time threshold value Time 2 is not limited to 50 milliseconds.

The time threshold value Time 3 is a threshold value for differentiating a change of the jerk J due to stoppage of movement of the remote controller 1 after a lifting and a change of the jerk J due to a collision. The time threshold value Time 3 is decided on the basis of the amount of time of change of the jerk J that occurs when the remote controller 1 hits against something. In this embodiment the time threshold value Time 3 is 50 milliseconds, but the time threshold value Time 3 is not limited to 50 milliseconds.

Next, a method to determine a factor to change a jerk J using the above threshold values will be described in detail.

FIG. 2 illustrates one example of change of a jerk J with time when the user lifts the remote controller 1 . As illustrated in FIG. 2 , the jerk J increases at two timings: the moment when the user lifts the remote controller 1 and the moment when movement of the remote controller 1 is stopped after the lifting.

The factor determination means 13 specifies the factor to change the jerk J in such a way that change of the jerk J by a lifting of the remote controller 1 is divided into four phases, Phase 1 to Phase 4 as illustrated in FIG. 2 and processed.

(Phase 1 )

The phase until the jerk J exceeds the threshold value Th 1 is Phase 1 . In Phase 1 , the factor determination means 13 monitors whether the jerk J exceeds the threshold value Th 1 . In FIG. 2 , at a time point t 1 (a first time point), the jerk J exceeds the threshold value Th 1 . At this time point t 1 , the factor determination means 13 proceeds from Phase 1 to Phase 2 .

(Phase 2 )

In Phase 2 , the factor determination means 13 starts to measure an amount of time. A measured amount of time is called T. The factor determination means 13 further monitors whether the jerk J exceeds the threshold value Th 2 and whether the jerk J decreases to less than the threshold value Th 1 . In FIG. 2 , the jerk J decreases less than the threshold value Th 1 at a time point t 2 . At the time point t 2 , the factor determination means 13 proceeds from Phase 2 to Phase 3 .

(Phase 3 )

In Phase 3 , the factor determination means 13 determines whether the jerk J exceeds the threshold value Th 1 again. In FIG. 2 , at a time point t 3 (a second time point), the jerk J exceeds the threshold value Th 1 again; and at the time point t 3 the measured amount of time T exceeds the time threshold value Time 2 . In such a case, the factor determination means 13 proceeds from Phase 3 to Phase 4 .

(Phase 4 )

In Phase 4 , the factor determination means 13 determines whether the jerk J exceeds the threshold value Th 2 within the time threshold value Time 3 . In FIG. 2 , after proceeding to Phase 4 at the time point t 3 , the time threshold value Time 3 has passed without the jerk J exceeding the threshold value Th 2 . In such a case, the factor determination means 13 determines that change of the jerk J is caused by a lifting of the remote controller 1 by the user.

(Collision Movement)

FIG. 3 illustrates one example of change of a jerk J with time when the remote controller 1 hits against a floor. As illustrated in FIG. 3 , when the remote controller 1 hits against a floor, a great jerk J occurs. Once the jerk J exceeds the threshold value Th 1 , the factor determination means 13 proceeds from Phase 1 to Phase 2 . In Phase 2 , if the jerk J exceeds the threshold value Th 2 , the factor determination means 13 determines that the factor that changes the jerk J is that the remote controller 1 has hit against something.

(Minute Vibration 1 )

FIG. 4 illustrates one example of change of a jerk J with time when a minute vibration is applied to the remote controller 1 . When a minute vibration is applied to the remote controller 1 , a vibration occurs with a small jerk J and a short vibration time. In FIG. 4 , since the jerk J does not exceed the threshold value Th 1 , Phase 1 does not proceed to Phase 2 .

(Minute Vibration 2 )

FIG. 5 illustrates another example of a jerk J with time when a minute vibration is applied to the remote controller 1 . In this example, since the jerk J exceeds the threshold value Th 1 , the factor determination means 13 proceeds from Phase 1 to Phase 2 . Next, since the jerk J decreases to less than the threshold value Th 1 , the factor determination means 13 proceeds from Phase 2 to Phase 3 . In Phase 3 , since the time threshold value Time 1 has passed while the jerk J remains less than the threshold value Th 1 , the factor determination means 13 determines that the factor that changes the jerk J is a minute vibration.

Returning to FIG. 1 , the sleep control means 14 sets or cancels the sleep state of the remote controller 1 . The sleep control means 14 cancels the sleep state of the remote controller 1 if the factor determination means 13 determines that the user is holding the remote controller 1 in his/her hand. More specifically, the sleep control means 14 controls ON/OFF of the display of the display 5 , for example. If display of the display 5 is turned off, that is, in the sleep state, power consumption can be reduced.

Once a predetermined period has passed after the user stops the operation of the remote controller 1 , the sleep control means 14 turns off the LCD composing the display 5 of the remote controller 1 , and if it is determined that the remote controller 1 is lifted, the sleep control means 14 turns on the LCD. The sleep control means 14 may turn on or off the backlight composing the display 5 .

Next, operation of the remote controller 1 according to this embodiment will be described.

FIG. 6 illustrates a flow chart of the entire processing of the remote controller 1 . As illustrated in FIG. 6 , after power activation, the controller 10 performs an operation processing subroutine to receive the operation from the user (Step S 1 ). After that, the controller 10 performs a standby processing subroutine (Step S 2 ). Then, the controller 10 repeats Steps S 1 and S 2 .

FIG. 7 illustrates a flow chart of an operation processing subroutine. As illustrated in FIG. 7 , the controller 10 first determines whether the user has performed an operation (Step S 11 ). Here, an operation by the user includes a press of an input button or a voice input.

If the user enters an operation input (Step S 11 ; Yes), the operation control means 11 performs remote control processing corresponding to the operation input (Step S 12 ). For example, where an appliance to be operated by the user is an air conditioner, when the user presses a power button, the remote controller 1 transmits a power-on signal to the air conditioner, thereby turning on the air conditioner. After remote control processing, the controller 10 returns processing to Step S 11 .

Meanwhile, if there is no operation input from the user (Step S 11 ; No), the controller 10 determines whether a predetermined amount of time (for example, 30 seconds) has passed after the last operation by the user (Step S 13 ). For example, if no user operation is performed after power activation, the amount of time to be determined is the amount of time after the power activation. If a predetermined amount of time has not passed yet (Step S 13 ; No), the controller 10 returns processing to Step S 11 .

If a predetermined amount of time has passed after the last operation by the user (Step S 13 ; Yes), it is determined that a user operation has been completed, and the sleep control means 14 sets the display 5 to be in the sleep state (display is OFF) (Step S 14 ). Here, the sleep control means 14 stores information displayed on the display 5 in the memory 7 . After Step S 14 , the controller 10 terminates the operation processing subroutine.

FIG. 8 illustrates a flow chart of a stand-by processing subroutine S 2 . As illustrated in FIG. 8 , the calculation means 12 first starts to calculate a jerk J (Step S 21 ). After that, the calculation means 12 calculates the jerk J on the basis of an acceleration to be output from the acceleration sensor 3 at regular intervals.

Subsequently, the factor determination means 13 performs a factor determination processing subroutine to determine the factor that changes the jerk J (Step S 22 ). This factor determination processing subroutine will be described later.

Next, the factor determination means 13 determines whether the factor that changes the jerk J, which was subjected to the factor determination processing subroutine, is a lifting by the user (Step S 23 ). If it is determined that the factor that changes the jerk J is not a lifting by the user (Step S 23 ; No), the factor determination means 13 returns processing to Step S 22 . After that, until it is determined that the factor that changes the jerk J is a lifting by the user (Step S 23 ; Yes), Steps S 22 and S 23 will be repeated.

Meanwhile, if it is determined that the factor that changes the jerk J is a lifting by the user (Step S 23 ; Yes), the sleep control means 14 cancels the sleep state of the display 5 and turns on display of the display 5 (Step S 24 ). The sleep control means 14 reads out information stored in the memory 7 and causes the display 5 to display the information. Information to be displayed on the display 5 may be different information, and immediately after power activation, an image of default setting may be displayed. Then, calculation of the jerk J by the calculation means 12 is terminated.

The user may operate the remote controller 1 without lifting the remote controller 1 . For example, the user may press a button of the remote controller 1 without touching the housing of the remote controller 1 . In this case, it is desirable that the controller 10 can perform remote controller processing of Step S 12 by interrupting the processing even if the display 5 is in the sleep state.

FIG. 9 illustrates a flow chart of a factor determination processing subroutine to determine a factor to change a jerk J. This subroutine is divided into four phases from Phases 1 to 4 , as described above.

As illustrated in FIG. 9 , in Phase 1 , the factor determination means 13 waits until the jerk J exceeds the threshold value Th 1 (Step S 31 ; No).

Once the jerk J exceeds the threshold value Th 1 (Step S 31 ; Yes), the factor determination means 13 proceeds to Phase 2 . In Phase 2 , the factor determination means 13 starts to measure time after the jerk J exceeds the threshold value Th 1 (Step S 32 ). That is, at this point, measured time T=0.

Next, the factor determination means 13 determines whether the jerk J further increases to exceed the threshold value Th 2 (Step S 33 ).

If the jerk J exceeds the threshold value Th 2 (Step S 33 ; Yes), the factor determination means 13 determines that the remote controller has hit against something (Step S 35 ). After Step S 35 , the factor determination means 13 terminates the factor determination processing subroutine.

Meanwhile, if the jerk J does not exceed the threshold value Th 2 (Step S 33 ; No), the factor determination means 13 determines whether the jerk J decreases to less than the threshold value Th 1 again (Step S 34 ). If the jerk J does not decrease to less than the threshold value Th 1 (Step S 34 ; No), the factor determination means 13 returns to Step S 33 . In this way, until the jerk J exceeds the threshold value Th 2 (Step S 33 ; Yes) or decreases to less than the threshold value Th 1 (Step S 34 ; Yes), Steps S 33 and S 34 will be repeated.

If the jerk J decreases to less than the threshold value Th 1 (Step S 34 ; Yes), the factor determination means 13 proceeds to Phase 3 . In Phase 3 , the factor determination means 13 determines whether the jerk J exceeds the threshold value Th 1 again (Step S 36 ). If the jerk J does not exceed the threshold value Th 1 (Step S 36 ; No), the factor determination means 13 determines whether the time threshold value Time 1 has passed (Step S 37 ). If the time threshold value Time 1 has not passed (Step S 37 ; No), the factor determination means 13 returns processing to Step S 36 .

If the time threshold value Time 1 has passed (Step S 37 ; Yes), the factor determination means 13 determines that the factor that changes the jerk J is a minute vibration that is not caused by a lifting by the user (Step S 38 ) and terminates factor determination processing subroutine.

If the jerk J exceeds the threshold value Th 1 (Step S 36 ; Yes), the factor determination means 13 determines whether the measured amount of time T exceeds the time threshold value Time 2 (Step S 39 ). If the measured amount of time T does not exceed the time threshold value Time 2 (Step S 39 ; No), the factor determination means 13 returns processing to Step S 33 .

Meanwhile, if the measured amount of time T exceeds the time threshold value Time 2 (Step S 39 ; Yes), the factor determination means 13 sets the point at which the jerk J exceeds the threshold value Th 1 (the second time point) to be T=0 (Step S 40 ). After that, the factor determination means 13 determines whether the jerk J exceeds the threshold value Th 2 (Step S 41 ). If it is determined that the jerk J exceeds the threshold value Th 2 (Step S 41 ; Yes), the factor determination means 13 determines that the factor that changes the jerk J is caused by a collision (Step S 35 ) and terminates factor determination processing subroutine.

Meanwhile, if it is determined that the jerk J does not exceed the threshold value Th 2 (Step S 41 ; No), the factor determination means 13 determines whether the measured amount of time T from the second time point exceeds the time threshold value Time 3 (Step S 42 ). If the measured amount of time T does not exceed the time threshold value Time 3 (Step S 42 ; No), the factor determination means 13 returns processing to Step S 41 .

Meanwhile, if it is determined that the measured amount of time T exceeds the time threshold value Time 3 (Step S 42 ; Yes), the factor determination means 13 determines that the factor that changes the jerk J is a lifting of the remote controller 1 by the user (Step S 43 ) and terminates factor determination processing subroutine.

The above factor determination processing subroutine is summarized as below.

If the jerk J exceeds the threshold value Th 1 at the time point t 1 and then decreases to less than the threshold value Th 1 and remains without exceeding the threshold value Th 1 again while the amount of time from the time point t 1 exceeds the time threshold value Time 1 (Step S 37 ; Yes), the factor determination means 13 determines that the user is not holding the remote controller 1 in his/her hand (Step S 38 ).

Further, if, after the time point t 1 , the jerk J exceeds the threshold value Th 2 without decreasing to less than the threshold value Th 1 or the jerk J exceeds the threshold value Th 2 by the time threshold value Time 2 has passed (Step S 33 ; Yes), the factor determination means 13 determines that the user is not holding the remote controller 1 in his/her hand (Step S 35 ).

Further, if the jerk J exceeds the threshold value Th 1 at the time point t 1 , then decreases to less than the threshold value Th 1 and exceeds the threshold value Th 1 again while the amount of time from the time point t 1 to the point of exceeding the threshold value Th 1 again exceeds the time threshold value Time 2 (Step S 39 ; Yes) but the jerk J exceeds the threshold value Th 2 by the time threshold value Time 3 has passed since the time point t 3 (Step S 41 ; Yes), the factor determination means 13 determines that the user is not holding the remote controller 1 in his/her hand (Step S 35 ).

That is, if the jerk J exceeds the threshold value Th 1 at the time point t 1 , then decreases to less than the threshold value Th 1 and exceeds the threshold value Th 1 again and the amount of time from the time point t 1 to the point of exceeding the threshold value Th 1 again is within the time threshold value Time 1 and beyond the time threshold value Time 2 (Step S 39 ; Yes), and if the jerk J does not exceed the threshold value Th 2 until the time threshold value Time 3 has passed from the time point t 3 (Step S 42 ; Yes), the factor determination means 13 determines that the user is holding the remote controller 1 in his/her hand (Step S 43 ).

The factor determination means 13 may always determine that the user is not holding the remote controller 1 in his/her hand if the jerk J exceeds the threshold value Th 2 .

As described in detail above, in this embodiment, if it is determined that the user is holding the remote controller 1 in his/her hand on the basis of a change of the jerk J regarding movement of the remote controller 1 that is obtained from an acceleration detected by the acceleration sensor 3 , the sleep state of the display 5 is cancelled. This prevents the sleep state from being cancelled for movement of the remote controller 1 caused by a different factor such as a collision, thereby further reducing power consumption.

The remote controller 1 of an air conditioner is usually placed on a desk or the like, and when the air conditioner is used, the user generally operates the remote controller 1 in his/her hand. In this embodiment, while the remote controller 1 is not being operated, display of the display 5 is off, and when it is determined that the user is holding the remote controller 1 in his/her hand, display of the display 5 is turned on. This allows for the same operability as that of continuous display of the remote controller 1 and also can reduce power consumption. As a result, the frequency of replacement and charge of the battery of the battery-driven remote controller 1 can be reduced.

In this embodiment, a lifting of the remote controller 1 has been described. In a case where the remote controller 1 is pulled down from above, since change of the jerk J is almost the same as that of the lifting, the same effect can be obtained.

In this embodiment, the jerk J is used as an index value regarding movement of the remote controller 1 . This enables the lifting of the remote controller 1 by the user to be determined with a high degree of accuracy, regardless of the posture of the remote controller 1 , that is, an orientation of gravity.

In this embodiment, during operation of the remote controller 1 (while the user is operating the remote controller 1 ), calculation of the jerk J and determination of the factor that changes the jerk J are not performed. This further reduces power consumption that would be required to calculate the jerk J and determine the factor that changes the jerk J. The sleep control means 14 may stop operation of the acceleration sensor 3 and/or timer 6 if the electrical device is not in the sleep state.

At least one of the threshold values Th 1 and Th 2 and time threshold values Time 1 and Time 2 and Time 3 may be adjustable. In this case, the adjustment is preferably performed according to the shape, weight and use of the remote controller 1 . This permits more accurately the detection that the user is holding the remote controller 1 in his/her hand.

Intervals between calculations of a jerk J may be adjustable. For example, where the controller 10 has a learning function, if a jerk is not detected for a long time, intervals between calculations of the jerk J may be longer. This can curb useless detection of a jerk J, further reducing power consumption.

In this embodiment, a lifting of the remote controller 1 is determined using the rate of the jerk J and the amount of time of change, but the frequency of the jerk J can be used. In this case, for example, the factor determination means 13 is subjected to a waveform of the jerk J to Fourier transformation to obtain a frequency characteristic. Further, the factor determination means 13 determines the lifting of the remote controller on the basis of the difference in frequency between the lifting and the collision of the remote controller 1 . For example, the factor determination means 13 determines that the remote controller 1 is lifted by the user if both frequencies at the moment when the jerk J exceeds the threshold value Th 1 twice are lower than the frequency threshold value Fth.

That is, the factor determination means 13 may determine that the user is not holding the remote controller 1 in his/her hand if the frequency component of the jerk J 3 during the time threshold value Time 2 from the time point t 1 and during the time threshold value Time 3 from the time point t 3 includes a component higher than the frequency threshold value Fth. By using the frequency component of the jerk J in this way, the same effect as that of the above embodiment can be obtained.

Although a jerk J is used as an index value for determining a lifting of the remote controller 1 , an acceleration can be used as an index value. In this case, a gravity acceleration is stored, the calculation means 12 calculates the acceleration by subtracting the gravity acceleration from the acceleration detected by the acceleration sensor 3 , and using the calculated acceleration as an index value to perform determination. This allows for the same effect as the above embodiment in determination with the use of an acceleration.

FIG. 10 illustrates another configuration of the remote controller 1 . As illustrated in FIG. 10 , this remote controller 1 further includes a communicator 8 instead of the memory 7 .

The communicator 8 communicates with an external device to receive information under the control of the sleep control means 14 when the sleep state of the remote controller 1 is cancelled. The sleep control means 14 causes the display 5 to display information the communicator 8 received from the external device when it is detected that the user is holding the remote controller 1 in his/her hand. In this way, information on operation can be obtained between the time when the user is holding the remote controller 1 in his/her hand and the time when the user starts to operate the remote controller 1 , and the information is on the display 5 when the user actually operates the remoter controller 1 .

The sleep control means 14 may cause a component, such as the operating portion 2 , transmitter 4 and communicator 8 , except the display 5 , to be in the sleep state.

The controller 10 may detect a failure of the acceleration sensor 3 . For example, if the acceleration sensor 3 has failed, then output acceleration may not change. The controller 10 determines that the acceleration sensor 3 has failed if the acceleration output from the acceleration sensor 3 does not change when the remote controller 1 is being operated, for example. In this way, a failure of the acceleration sensor 3 can be promptly detected, and thus a failure of the remote controller 1 can be addressed immediately.

In this embodiment, the case where the remote controller 1 is used has been described. However, the present invention can be applied to a case other than where the remote controller 1 is used. The present invention can be applied to any electrical device as long as the electrical device requires a display function when the user is operating the electrical device and does not require a display function when the user is not operating the electrical device. Such a device could include, for example an electronic calculator or a mobile phone.

A program to be executed in the above embodiment may be stored and distributed in a computer-readable recording medium such as a flexible disk, a compact disk read-only memory (CD-ROM), a digital versatile disk (DVD) and a magneto-optical disk (MO), and by installing the program, a system to perform the above processing may be configured.

Alternatively, a program may be stored in a disk device or the like in a predetermined server device on a communication network such as the Internet, and be downloaded, for example, by superimposing the program on carrier waves.

Where the above functions are implemented by being shared by an operating system (OS) or where the above functions are implemented by cooperation of OS and an application, only that part other than OS may be stored and distributed in a medium or be downloaded.

The present invention is not limited by the above embodiment and drawings. It should be appreciated that the embodiment and drawings can be modified without departing from the principle of the present invention.

The present invention is suitable for an electrical device, such as a remote controller, that a user uses in his/her hand.