Image reading apparatus and document feeding method in image reading apparatus

1. Field of the Invention

This invention relates to an image reading apparatus which reads a document automatically fed onto document glass and a method for feeding documents in the image reading apparatus.

2. Description of the Related Art

With an image reading scanner, a digital copying machine or the like provided with an automatic document feeding device, a special document, small in size and great in thickness, such as a business card, cannot be fed by an automatic document feeding device which is for feeding sheets of paper of ordinary paper size. To cope with this, conventionally, an operator must manually set business cards on document glass to read or copy the business cards or a separate scanner dedicated to reading business cards must be used to read business cards.

However, in the former case, it is a time-consuming job to arrange business cards on document glass, and this significantly impairs efficiency. If a scanner dedicated to reading business cards is used as in the latter case, reading accuracy is markedly degraded because such scanners are very low in reading speed and resolution, and further it is required to ensure a space for the dedicated scanner.

Therefore, image reading apparatuses have been demanded to be capable of feeding documents, even if they are special documents, small in size and great in thickness, with ease and efficiency, and reading the images of documents with high resolutions.

An object of the present invention is to make it possible to read special documents, such as business cards, at high speed and with high resolutions and ease, using an image reading apparatus provided with an automatic document feeding device, and to enhance the efficiency of reading special documents and the accuracy of read images.

A further object of the present invention is to make effective use of part of the automatic document feeding device of an image reading apparatus, and thereby save dedicated space which would be otherwise required for reading special documents, such as business cards.

According to the present invention, an image reading apparatus comprising a reading means which reads the images of documents fed into an image reading area, a first document feeding means which feeds a first document into the first image reading area of the reading means, and a second document feeding means which is detachably mounted on the first document feeding means and feeds a second document into the second image reading area of the reading means is provided.

Further, according to the present invention, an image reading apparatus comprising a reading device which reads the images of documents fed into an image reading area, a first document feeding device which feeds a first document into the first image reading area of the reading device, and a second document feeding unit which is detachably mounted on the first document feeding device and feeds a second document into the second image reading area of the reading device is provided.

Further, according to the present invention, a method for feeding documents in the image reading apparatus which method comprises feeding a first document from a first side into the first image reading area of the reading device, and feeding a second document from the side opposite the first side of the reading device into the second image reading area of the reading device is provided.

FIG. 1 is an illustration schematically showing the configuration of a scanner embodying the present invention;

FIG. 2 is a schematic perspective view illustrating an automatic document feeding device embodying the present invention;

FIG. 3 is an exploded perspective view of a document feeding unit as mounted to the first document feeding device of the automatic document feeding device embodying the present invention;

FIG. 4 is an illustration schematically showing the configuration of the automatic document feeding device embodying the present invention;

FIG. 5 is an illustration schematically showing the configuration of the document feeding unit embodying the present invention;

FIG. 6 is an exploded perspective view schematically showing the drive system of the document feeding unit embodying the present invention;

FIG. 7 is a flowchart illustrating part of business card document reading operation by the document feeding unit embodying the present invention;

FIG. 8 is a flowchart illustrating part subsequent to FIG. 7 of business card document reading operation by the document feeding unit embodying the present invention; and

FIG. 9 is a schematic illustration showing feeding of business cards by a document feeding unit, an example of modification to the present invention.

Referring to the attached drawings, preferred embodiments of the present invention are described below in details. FIG. 1 schematically illustrates the configuration of a scanner 10 which is an image reading apparatus embodying the present invention and is mounted with a CCD sensor 11 . Document glass 12 made of a transparent glass plate and a reading window 13 made of a glass plate for reading documents fed by an automatic document feeding device 28 described below are formed above the CCD sensor 11 .

Image reflected light from a document placed on the document glass 12 or a document passed on the reading window 13 is projected into the CCD sensor 11 by an optical system 8 comprising a lamp 17 , first through third mirrors 18 , 20 , and 21 , and a lens 23 wherein light is gathered onto a reflector 14 . The reflector 14 , the lamp 17 and the first mirror 18 are mounted on a first carriage 24 , and the second and third mirrors 20 and 21 are mounted on a second carriage 26 . The first carriage 24 and the second carriage 26 are driven by a drive pulley (not shown) controlled by a control board 30 and reciprocatory moved along rails not shown.

The through-read-type automatic document feeding device 28 which automatically feeds documents is installed on the document glass 12 . The automatic document feeding device 28 comprises a first document feeding device 30 which feeds ordinary documents G 1 of ordinary paper size, A 4 , B 4 or the like, as first document, onto the reading window 13 , and a document feeding unit 31 which is detachably mounted at the end of the document receiving tray 41 of the first document feeding device and feeds only business cards G 2 as second document.

The first document feeding device 30 is provided with a pick-up roller 33 which takes out documents G 1 on a document placement tray 32 , a separating roller 36 which is in slidable contact with a separating member 34 , first and second conveying rollers 37 and 38 which clamp documents G 1 between them and convey them, and an aligning roller 40 , and feeds ordinary documents G 1 onto the reading window 13 formed in the first reading area. Further, the first document feeding device 30 is provided with a guide 42 and an ejecting roller 43 which guide an ordinary document G 1 read through the reading window 13 toward the document receiving tray 41 using the first conveying roller 37 . Items marked with numbers of 44 a - 44 c are ribs which align ordinary documents G 1 , read and ejected onto the document receiving tray 41 , on a size-by-size basis.

The document feeding unit 31 is detachably mounted at the end of the document receiving tray 41 of the first document feeding device 30 on the side opposite the first conveying roller 37 side, by fitting the elastic projection 31 a on the document feeding unit 31 into the fitting hole 41 b formed in the notch 41 a in the document receiving tray 41 . For the reason, the document placement tray 32 is rotatable on a fulcrum 30 a so as not to interfere with the document feeding unit 31 .

Then the document feeding unit 31 is described in details. The document feeding unit 31 is provided with an insertion tray 46 dedicated to business cards on which business cards G 2 are to be placed, a paper supply sensor 46 a which detects any business card G 2 on the insertion tray 46 dedicated to business cards, a pair of upper and lowerpaper supply rollers 47 a and 47 b which feed business cards G 2 on the insertion tray 46 dedicated to business cards into the business card reading area [A] as the second reading area on the document glass 12 , a conveying roller 48 which conveys business cards G 2 in the business card reading area [A], a scooping Mylar sheet 52 which scoops up business cards G 2 and guides them toward a document receiving tray 50 , a pair of upper and lower ejecting rollers 51 a and 51 b which eject business cards G 2 onto the document receiving tray 50 , and an ejection sensor 50 a which detects business cards G 2 conveyed by the conveying roller 48 .

The item marked with “ 55 ” is a pulse motor which drives the conveying roller 48 through a gear wheel a 53 and a gear wheel b 54 . The driving force from the pulse motor 55 is transmitted from a first pulley 57 to a second pulley 58 through a first timing belt 56 to drive the upper-paper supply roller 47 a , and from a third pulley 61 to a fourth pulley 62 through a second timing belt 60 to drive the upper ejecting roller 51 a.

Then the principle of operation is described in case ordinary documents G 1 are fed onto the reading window 13 using the first document feeding device 30 and the documents are read, the documents G 1 are placed on the document placement tray 32 , and thereafter, a print key not shown is turned on to start reading operation. At this time the document feeding unit 31 may be left mounted on the document receiving tray 41 . In ordinary cases, however, the document feeding unit 31 is dismounted so as not to interfere with ejection of ordinary documents G 1 .

When reading operation is started, the pick-up roller 33 is rotated to take ordinary documents G 1 out of the document placement tray 32 , and only the uppermost ordinary document G 1 is conveyed toward the first and second conveying rollers 37 and 38 by the separating member 34 and the separating roller 36 . Then the ordinary document G 1 is conveyed by the first and second conveying rollers 37 and 38 , and has its front end aligned by the aligning roller 40 . In this state the ordinary document is fed onto the reading window 13 . At this time the first and second carriages 24 and 26 are stopped in the position shown by a dotted line in FIG. 1 so as to read an image through the reading window 13 located in the first reading area.

When the ordinary documents G 1 are conveyed by the first and second conveying rollers 37 and 38 and passed on the reading window 13 one by one, in the optical system the lamp 17 is turned on, and the ordinary documents G 1 are irradiated with light through the reading window 13 . Light from the lamp 17 , reflected from the ordinary document G 1 , is projected into the CCD sensor 11 through the first through third mirrors 18 , 20 , and 21 and the lens 23 , and the image of the ordinary document G 1 is formed there. Thus the ordinary documents G 1 are read one by one, and the image information of the ordinary documents G 1 is stored in a storage device not shown. Thereafter, the ordinary documents G 1 passed on the reading window 13 are guided toward the ejecting roller 43 by the guide 42 , and ejected onto the document receiving tray 41 by the ejecting roller 43 , thus the image reading operation being completed.

In case an ordinary document G 1 is manually fed by an operator, the automatic document feeding device 28 is opened, and the ordinary document G 1 is placed on the document glass 12 . Thereafter, the print key is turned on to start reading operation. Then the lamp 17 is turned on, and the first second carriages 24 and 26 in their home positions are scanned in the direction of the arrow s. While this is being done, light from the lamp 17 reflected from the ordinary document G 1 is projected into the CCD sensor 11 through the first through third mirrors 13 , 20 , and 21 and the lens 23 , and the image of the document G 1 is formed there. Thus the ordinary documents G 1 are read one by one, and the image information of the ordinary documents G 1 is stored in a storage device not shown.

Then cases where business cards G 2 are fed into the business card reading area [A] using the document feeding unit 31 and read there are described below referring to the flowcharts in FIG. 7 and FIG. 8 . To read business cards G 2 , first, the projection 31 a on the document feeding unit 31 is fit into the fitting hole 41 b in the document receiving tray 41 to mount the document feeding unit 31 on the document receiving tray 41 .

Then, business cards G 2 are set on the insertion tray 46 dedicated to business cards in Step 100 , and thereafter, the print key not shown is turned on to start operation of reading the business cards G 2 in Step 101 . The operation proceeds to Step 102 , and comparison is made to judge whether the paper supply sensor 46 a is turned on or not. If there is no business card G 2 set on the insertion tray 46 dedicated to business cards and the paper supply sensor 46 a is not turned on in Step 102 , an error indication is given on a display panel not shown. When the paper supply sensor 46 a is found on in Step 102 , the operation proceeds to Step 103 .

In Step 103 , the first and second carriages 24 and 26 in their home positions are slid to the position indicated by a solid line in FIG. 1 in the direction of the arrow s so that image reading may be performed in the business card reading area [A], and then the operation proceeds to Step 104 . In Step 104 , the pulse motor 55 is turned on, and then the operation proceeds to Step 106 . In Step 106 the pulses of the pulse motor 55 are counted until a certain count is reached, and then operation of reading the business cards G 2 is started.

That is, the conveying roller 48 is rotated in the direction of the arrow t through the gear wheel a 53 and the gear wheel b 54 , and further, the upper paper supply roller 47 a is rotated in the direction of the arrow u and the upper ejecting roller 51 a is rotated in the direction of the arrow v to feed business cards G 2 toward the conveying roller 48 by the paper supply rollers 47 a and 47 b . Then the business cards G 2 are conveyed by the conveying roller 48 and passed through the business card reading area [A] one-by one.

While this is being done, in the optical system the lamp 17 is turned on, and the business card G 2 is irradiated with light in the business card reading area [A]. Light from the lamp 17 reflected from the business card G 2 is projected into the CCD sensor 11 through the first through third mirrors 18 , 20 , and 21 and the lens 23 , and the image of the business card G 2 is formed there. The business cards G 2 are read one by one, and the image information of the business cards G 2 is stored in the storage device not shown. Thereafter, the business cards G 2 passed through the business card reading area [A] are guided toward the ejecting rollers 51 a and 51 b by the scooping Mylar sheet 52 , and ejected onto the document receiving tray 50 by the ejecting rollers 51 a and 51 b.

When the paper supply sensor 46 a detects the passage of a business card G 2 in Step 107 while this is being done, the operation proceeds to Step 108 . If the passage of a business card G 2 is not detected for a specified period of time in Step 107 , that is judged as a paper jam, and an error indication is given on the display panel. In Step 108 , after the passage of a business card G 2 by the paper supply sensor 46 a , the pulses of the pulse motor 55 are counted until a certain count is reached. Then the first and second carriages 24 and 26 are returned from the business card reading area [A] to their home positions to prepare for the completion of reading operation, and the operation proceeds to Step 110 .

In Step 110 comparison is made to judge whether the front end of the business card G 2 has reached the ejection sensor 50 a or not. If the front end of the business card G 2 has not reached, an error indication is given on the display panel. When it is found that the front end of the business card G 2 has reached the ejection sensor 50 a , the operation proceeds to Step 112 .

In Step 112 the pulse motor 55 is run, and then the operation proceeds to Step 113 . In Step 113 comparison is made to judge whether the tail end of the business card G 2 has passed by the ejection sensor 50 a or not. If the tail end of the business card G 2 has not passed, an error indication is given on the display panel. If it is judged that the tail end of the business card G 2 has passed by the ejection sensor 50 a , the operation proceeds to Step 114 , in which the pulse motor 55 is stopped, and the operation of reading the business card G 2 is completed. After the completion of business card G 2 reading operation, the document feeding unit 31 is removed from the document receiving tray 41 .

According to this constitution, business cards G 2 can be easily read without damage to the business cards G 2 by detachably mounting the document feeding unit 31 dedicated to business cards G 2 at the end of the document receiving tray 41 in the first document feeding device 30 , feeding the business cards G 2 into the business card reading area [A] of the CCD sensor 11 by means of the document feeding unit 31 , and then reading images there. With this constitution, it is unnecessary for an operator to place business cards G 2 on the document glass as in conventional cases or to use a reading device dedicated to reading of business cards G 2 . Further, the first document feeding device 30 conveys ordinary documents G 1 only on the conveying roller 37 side of the document receiving tray 41 , and the document feeding unit 31 uses the side of the document receiving tray 41 which has no influence on the conveyance of ordinary documents G 1 . Therefore, there is not a possibility that thee conveyance of ordinary documents G 1 is interfered with.

As a result, business cards G 2 can be read with ease using a high-speed scanner 10 , and higher document resolutions are obtained. Furthermore, part of the document receiving tray 41 of the first document feeding device 30 can be effectively utilized without interfering with ordinary document G 1 discharging operation, and space for installation can be saved.

It is to be understood that the present invention is not limited to the above-mentioned embodiments and changes and variations may be made without departing from the sprint or scope of the following claims. For example, the construction and the like of the first document feeding device are optional as long as first documents of ordinary size and the like can be fed and ejected on its one side, and those which automatically flips over documents with print on both their sides and feeds them may be adopted. As for the document feeding unit, those which are provided with a document separating mechanism at their paper supply unit and continuously feed second documents, such as business cards, may be used as well as those which feed documents one by one, and second documents may be post cards and the like.

Further, like an example of modification illustrated in FIG. 9, a lens 70 may be placed in a position opposite the conveying roller 48 on the document feeding unit 31 in the above-mentioned embodiments so that business cards G 2 may be provided to the business card reading area [A] on the document glass 12 through the lens 70 . Thus the curve of the path in which business cards G 2 are fed by the document feeding unit 31 can be made more gentle, and deformation in business cards G 2 which may occur when they are passed through the document feeding unit 31 can be further reduced.

In addition there is not any restriction on methods for processing image data acquired by means of the image reading apparatus, and such image data may be treated in any way. Image data may be managed as sets of data by storing it in fixed sizes or the like, or stored data may drawn and used over a network, or image data may be converted into text data or numerical data for the purpose of data cataloging.

As described above in details, according to the present invention, business cards and the like can be easily read with higher resolutions using a through-read-type image reading apparatus by detachably mounting the document feeding unit for feeding only specific documents, such as business cards, on the first document feeding device on the side opposite the document supply side, and feeding specific documents which cannot be fed by the first document feeding device without interfering with document supplying operation by the first document feeding device. Further, it is unnecessary to ensure space specially for the installation of a document feeding unit, and space for installation can be saved.