JP2011211477A - Image reader, image reading method, and image reading program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image reader, an image reading method, and an image reading program wherein double feed can be detected reliably.SOLUTION: The sheet length is determined (S2). When the sheet length is determined, the width of an image is determined (S8). A decision is made whether the width of an image thus determined is wider than or equal to the sheet width or not (S9), and when a decision is made that the width of an image is not wider than or equal to the sheet width (S9:No), image data of the coordinate position X is erased (S11). When the image data is erased, a generated image from which a projecting part is deleted is generated. A decision is then made whether the length of the generated image is longer than the sheet length or not (S14). When a decision is made that the length of the generated image is longer than the sheet length (S14:Yes), "occurrence of double feed" is displayed (S15).

Description

  The present invention relates to an image reading apparatus, an image reading method, and an image reading program for reading an image of a conveyed sheet.

  2. Description of the Related Art Conventionally, various reading apparatuses having means for detecting double feeding in a state where sheets to be read are conveyed while being overlapped have been proposed. As an example, a reading device disclosed in Patent Document 1 is known.

  The reading device disclosed in Patent Document 1 includes a sheet length detection unit, a conveyance length detection unit, a double feed detection unit, and a control unit. The sheet length detection unit detects the length of the sheet to be read. The conveyance length detection unit detects a conveyance length that is the length in the conveyance direction of a sheet including attached paper such as sticky notes and paper pieces attached to the sheet. The double feed detection unit detects double feed of sheets when the sheets are conveyed while being overlapped.

  The control unit is configured such that the conveyance length of the sheet detected by the conveyance length detection unit is longer than the sheet length detected by the sheet length detection unit, and the length obtained by subtracting the difference between the conveyance length and the sheet length from the sheet length. Is determined to be double feed on the sheet when it is substantially equal to the double feed length detected by the double feed detection unit. Therefore, when the sheets are conveyed while being overlapped as shown in FIG. 10, the sheet conveyance length La is longer than the sheet length Lb, and the difference between the sheet conveyance length La and the sheet length Lb is determined from the sheet length Lb. It is determined that the subtracted length Lc = Lb− (La−Lb) = 2Lb−La is approximately equal to the double feed length Lc1 detected by the double feed detection unit. Therefore, it is determined that double feeding has occurred in the sheet.

JP 2008-13345 A

  However, the reading device disclosed in Patent Document 1 reliably detects double feeding when there is attached paper such as a sticky note that extends over a portion where two sheets overlap and a portion where only one sheet overlaps. Can not. This point will be described in detail with reference to FIG.

  Consider a case where there is an attached paper AS that extends over a portion DR in which two sheets overlap and a portion SR in which only one sheet is present as shown in FIG. In this case, the double feed detection unit detects the length between the one end SE of the sheet SH and the one end AE of the attached paper AS as the double feed length Lc2. Therefore, the true double feed length Lc = 2Lb−La is not determined to be substantially equal to the double feed length Lc2 detected by the double feed detection unit. Therefore, it is not determined that double feeding has occurred in the sheet, and there is a problem that reliable detection of double feeding cannot be performed.

  Also, the reading device disclosed in Patent Document 1 cannot reliably detect double feeding when, for example, as shown in FIG. 12, two sheets SH overlap each other and the attached paper AS protrudes from the sheet SH. . That is, since the transport length is not the length La but the length Le shown in FIG. 12, the length Lc determined by the relational expression Lc = 2Lb−La is equal to the double feed length detected by the double feed detection unit. It is not judged to be approximately equal. Therefore, there is a problem that it is impossible to reliably detect double feeding.

  SUMMARY An advantage of some aspects of the invention is to provide an image reading apparatus, an image reading method, and an image reading program capable of reliably detecting double feeding. is there.

  In order to achieve the above object, the present invention according to claim 1 is an image reading apparatus that reads an image of a sheet to be conveyed including a sheet and an attached sheet attached to the sheet, the image reading apparatus in a conveying direction of the sheet. A first acquisition unit that acquires a sheet length that is a length; an image reading unit that reads a transported image that is an image of the transported paper; and an image of the sheet among the transported images that are read by the image reading unit A recognition unit that recognizes a pop-up image that is a partial image of the attached paper that pops out from the sheet image in the transport direction, and the recognition unit among the transport images read by the image reading unit. Further, by deleting the pop-up image, an image processing unit that generates a generated image, a first determining unit that determines an image length that is a length of the generated image in the transport direction, and the first determining unit Determined said A first determination unit that determines whether an image length is greater than the sheet length acquired by the first acquisition unit, and the first determination unit determines that the image length is greater than the sheet length. When the determination is made, it is determined that a double feed, which is a state in which the sheets are overlapped and conveyed, has occurred.

  According to a second aspect of the present invention, in the first aspect of the present invention, a conveyance width that is a length in a direction intersecting the conveyance direction of the conveyed paper at each position of the conveyed paper in the conveyance direction is set. A second acquisition unit to acquire; a third acquisition unit to acquire a sheet width which is a length in a direction intersecting the transport direction of the sheet; and the transport width at each position of the transported paper is less than the sheet width And a second determination unit that determines whether the conveyance width is less than the sheet width by the second determination unit at each position of the transported paper. A part of the transported image of the transported paper that has been transferred is recognized as a part of the pop-up image of the attached paper that protrudes in the transport direction from the sheet, and the image processing unit is read by the image reading unit. Among the conveyed images, the recognition Accordingly, the is characterized in deleting the protruding image recognized in each position of the conveyed sheet.

  According to a third aspect of the present invention, in the second aspect of the invention, the second acquisition unit determines the conveyance width by determining the conveyance width from the conveyance image read by the image reading unit. It is characterized by acquiring.

  According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, a detection unit that detects the number of sheets of the transported paper at each position of the transported paper is provided, and is detected by the detection unit. Among the number of the conveyed papers at each position, the number of the paper parts corresponding to the generated image generated by the image processing unit at each position in the conveyance direction is two or more. A third determination unit that determines whether or not the image length is equal to or less than the sheet length by the first determination unit, and the conveyance of the generated image by the third determination unit When it is determined that the number of sheets at each position in the direction is two or more, it is determined that the double feeding has occurred.

  In order to achieve the above object, the present invention according to claim 5 is an image reading apparatus including an image reading unit that reads a transported image that is an image of a transported paper including a sheet and attached paper attached to the sheet. A first acquisition step of acquiring a sheet length that is a length in the transport direction of the sheet, and among the transport images of the transported paper read by the image reading unit A recognition step of recognizing a pop-up image that is a part of the attached paper popping out in the transport direction from a sheet image that is an image of the sheet, and among the transport images read by the image reading unit, An image processing step for generating a generated image by deleting the pop-up image recognized in the recognition step, and a first determination for determining an image length that is a length of the generated image in the transport direction. And a first determination for determining whether or not the image length determined in the first determination step is greater than a sheet length that is a length in the transport direction of the sheet acquired in the first acquisition step. And when the first determination step determines that the image length is larger than the sheet length, it is determined that a double feed, which is a state where the sheets are overlapped and conveyed, has occurred. It is a feature.

  In order to achieve the above object, the present invention according to claim 6 is an image reading apparatus including an image reading unit that reads a transported image that is an image of a transported paper including a sheet and an attached paper attached to the sheet. A first acquisition step of acquiring a sheet length that is a length in the transport direction of the sheet, and among the transport images of the transported paper read by the image reading unit A recognition step of recognizing a pop-up image that is an image of the attached paper that pops out in the transport direction from a sheet image that is an image of the sheet, and a recognition step among the transport images read by the image reading unit. An image processing step for generating a generated image by deleting the recognized pop-out image, and a first decision for determining an image length that is a length of the generated image in the transport direction. And a first determination for determining whether or not the image length determined in the first determination step is greater than a sheet length that is a length in the transport direction of the sheet acquired in the first acquisition step. And when it is determined by the first determination step that the image length is greater than the sheet length, it is determined that a double feed, which is a state in which the sheets are overlapped and conveyed, The step is realized by a computer.

  According to the image reading apparatus of the first aspect, the generated image is generated by deleting the pop-up image of the attached paper recognized by the recognition unit from the transport image. The transport image is an image of transported paper including the sheet and attached paper attached to the sheet. The pop-up image is an image that is recognized by the recognition unit as an image of attached paper that pops out in the transport direction from the sheet image that is the image of the sheet among the transport images of the transported paper. According to the image reading apparatus of claim 1, when it is determined that the image length that is the length in the conveyance direction of the generated image is larger than the sheet length that is the length in the conveyance direction of the sheet, double feeding occurs. It is determined that Therefore, it is possible to reliably detect double feeding.

  The effect produced by the image reading apparatus according to claim 1 will be described in detail with reference to FIG. FIG. 12 is a diagram illustrating a state in which two sheets with attached sheets are conveyed while being overlapped. In FIG. 12, the transport direction is defined as the X-axis direction, the direction intersecting the transport direction is defined as the Y-axis direction, and the direction intersecting the surface (consolidated) SF of the transported paper FS is defined as the Z-axis direction. The length of the paper in the X-axis direction is expressed as “length” or “long”, and the length of the paper in the Y-axis direction is expressed as “width”. The positive direction side of the Z axis is denoted as “upper”. The Z-axis negative direction side is expressed as “down”. Hereinafter, these definitions are common to other drawings.

  In FIG. 12, the transport length is the length Le in the transport direction of the transported paper FS including the sheet SH and the attached paper AS, that is, the X-axis direction. In the case shown in FIG. 12, the length Le is the length of the portion DR where two sheets SH overlap, the length of the portion SR where only one sheet SH is present, and the edge of the sheet SH of the attached paper AS in the X-axis direction. It is the sum total of the length of the part PJ jumping out. The sheet length is the length Lb of the sheet SH in the X-axis direction in FIG. The pop-out image is a partial image of the attached paper AS indicated by the length Ld in the X-axis direction in FIG. In FIG. 12, the image length is a length La obtained by subtracting the length Ld of the pop-up image from the transport length Le.

  When the second determination unit determines that the image length La is greater than the sheet length Lb, it is determined that a double feed, which is a state in which the sheets SH are overlapped and conveyed, has occurred. Accordingly, the portion of the attached paper AS that protrudes from the sheet SH is not included in each length that is a determination criterion for double feeding. Further, as shown in FIG. 12, even when there is an attached sheet AS that extends over a portion DR where two sheets overlap and a portion SR where only one sheet exists, the image length La is determined as the sheet length. It is determined by whether or not it is larger than the length Lb. Accordingly, as shown in FIG. 12, even if the attached sheet AS extending over the part DR and the part SR exists, it is determined that the sheet SH is overlapped only when the sheet SH is overlapped. As described above, according to the image reading apparatus of the first aspect, it is possible to reliably detect double feeding. According to the image reading apparatus of the first aspect, the generated image is deleted by deleting the pop-up image of the attached paper recognized by the recognition unit from the transported image of the transported paper read by the image reading unit. Is provided. That is, the image processing unit deletes the image of the portion of the attached paper that protrudes from the sheet from the image of the transported paper. Therefore, after the image of the part that interferes with the determination of double feeding is deleted by the image processing unit, the determination of double feeding is performed. Therefore, it is possible to reliably detect double feeding.

  According to the image reading apparatus of the second aspect, the transported paper whose transport width is determined to be less than the sheet width is recognized as a part of the attached paper that protrudes from both ends in the transport direction of the sheet. Therefore, it is possible to reliably detect double feeding.

  The effect of the image reading apparatus according to claim 2 will be described in detail with reference to FIG. In FIG. 12, the transport width is a width at each position in the transport direction of the transported paper FS, that is, an X coordinate position. Accordingly, the conveyance width of the portion where the X coordinate position shown in FIG. 12 is X1 is the width Lf of the attached paper AS. The conveyance width of the portion where the X coordinate position shown in FIG. 12 is X2 is the width Lg of the sheet SH. The sheet width is the width Lg of the sheet SH in FIG.

  An image of each portion of the transported paper FS that is determined to be less than the sheet width is recognized as an image of the attached paper AS that protrudes from both ends EG of the sheet SH in the transport direction. Accordingly, in FIG. 12, the image of the attached paper AS at the portion indicated by the length Ld is recognized as the image of the attached paper AS that protrudes from both ends EG. Of the transport image of the transported paper FS, the pop-up image of the attached paper AS recognized at each position in the X-axis direction is deleted. Accordingly, in FIG. 12, the image of the attached paper AS corresponding to the length Ld is deleted from the transported image of the transported paper FS. Therefore, after the image of the part that hinders the determination of double feeding is surely deleted by the image processing unit, the determination of double feeding is performed. Therefore, it is possible to reliably detect double feeding.

  According to the image reading apparatus of the third aspect, the conveyance width is determined from the conveyance image by the second acquisition unit. The transported paper determined that the determined transport width is less than the sheet width is recognized as a part of the attached paper protruding from both ends of the sheet transport direction. Therefore, it is possible to reliably detect double feeding.

  According to the image reading apparatus of claim 4, it is determined that the image length is equal to or less than the sheet length, and it is determined that the number of transported sheets at each position in the transport direction of the transported paper is two or more. In this case, it is determined that double feeding has occurred. Therefore, even when two or more sheets are conveyed in a completely overlapped state, it is possible to detect double feeding. Therefore, it is possible to reliably detect double feeding.

  The effect produced by the image reading apparatus according to claim 4 will be described in detail with reference to FIGS. 13 and 14. FIG. FIG. 13 is a diagram illustrating a state in which two sheets SH are conveyed while being completely overlapped. FIG. 14 is a side view of the sheet SH shown in FIG. 13 when viewed from the Y-axis direction. In FIG. 13, the image length is a length La obtained by subtracting the length Ld from the transport length Le. In FIG. 13, the sheet length is a length Lb in the conveyance direction of the sheet SH. As shown in FIG. 13, when two sheets SH are completely overlapped and conveyed, length La = length Lb, that is, the image length is equal to the sheet length. Therefore, it is determined that the image length is equal to or less than the sheet length. As shown in FIG. 14, the number of transported paper FS is detected at each position in the transport direction of the transported paper FS. Accordingly, the number of transported sheets FS in the portion where the X coordinate position shown in FIG. 14 is X1 is detected as approximately one. The number of portions in which the X coordinate shown in FIG. 14 is X2 is detected as two.

  It is determined whether or not the number of transported sheets FS at all positions in the transport direction of the generated image generated by the image processing unit, that is, the X-axis direction is two or more. The generated image is an image generated by deleting the pop-up image of the attached paper AS recognized by the recognition unit from the transported image of the transported paper FS read by the image reading unit. Accordingly, all positions in the X-axis direction of the generated image are all positions in the X-axis direction within the range indicated by the length La in FIG. Therefore, as shown in FIG. 14, when two sheets SH are completely overlapped and conveyed, the number of sheets is substantially equal to two at all positions in the X-axis direction. Accordingly, the number of sheets at all positions in the X-axis direction is determined to be two or more. From the above, as shown in FIG. 14, when two sheets are completely overlapped and conveyed, it is determined that the image length is equal to or less than the sheet length, and the number of sheets at all positions is determined to be two or more. Is done. Therefore, it is determined that double feeding has occurred. Therefore, even when two sheets are completely overlapped and conveyed, it is possible to reliably detect double feeding.

  According to the image reading method according to claim 5 and the image reading program according to claim 6, the generated image is generated by deleting the pop-up image of the attached paper recognized by the recognition step from the transport image. Is done. When it is determined that the image length that is the length of the generated image in the conveyance direction is larger than the sheet length that is the length of the sheet in the conveyance direction, it is determined that double feeding has occurred. Therefore, it is possible to reliably detect double feeding.

1 is a perspective view of an image reading apparatus 1 according to an embodiment of the present invention. FIG. 2 is an explanatory diagram for explaining the inside of the image reading apparatus 1. FIG. 6 is an explanatory diagram for explaining a relationship between the number of transported paper FS and a signal sg detected by a detection unit. FIG. 6 is an explanatory diagram for explaining a relationship between the number of transported paper FS and a signal sg detected by a detection unit. 2 is a functional block diagram illustrating an electrical configuration of the image reading apparatus 1. FIG. FIG. 6 is a diagram illustrating an example of sheet width and sheet length data of various sheets SH stored in a sheet data storage unit 72 of the image reading apparatus 1. FIG. 6 is an explanatory diagram for explaining a process for determining a width wf of a transported paper FS by a width determination unit 75 of the image reading apparatus 1. It is explanatory drawing for demonstrating the production | generation process of the production | generation image GI by the image process part 78 of the said image reading apparatus 1. FIG. 4 is a flowchart showing operation control of the image reading apparatus 1. It is explanatory drawing for demonstrating the case where the sheet | seat SH is conveyed overlapping. FIG. 10 is an explanatory diagram for explaining a case where there is an attached paper AS that extends over a portion DR in which two sheets SH overlap each other and a portion SR in which only one sheet SH is present. FIG. 6 is an explanatory diagram for explaining a case where there is an attachment sheet AS that extends over a portion DR in which two sheets SH overlap each other and a portion SR in which only one sheet SH is present, and a case in which there is an attachment sheet AS that protrudes from the sheet SH. . It is a figure which shows the state in which the 2 sheet | seat SH has overlapped completely and is conveyed. FIG. 14 is a side view when the sheet SH illustrated in FIG. 13 is viewed from the Y-axis direction.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

[Appearance of image reader]
FIG. 1 is a perspective view showing an appearance of the image reading apparatus 1 of the present embodiment. As illustrated in FIG. 1, the image reading apparatus 1 includes a paper feed tray 2, a reading unit 3, a paper discharge tray 4, a setting unit 5, and a display unit 6. The image reading apparatus 1 according to the present embodiment is a sheet feed scanner that reads a plurality of sheets placed on a sheet feeding tray 2 by a user while being conveyed in a reading unit 3.

  The sheet feeding tray 2 has guides 2A and 2B as shown in FIG. The guides 2A and 2B are movable in the direction of the guide width WG shown in FIG. The guides 2A and 2B are pushed or widened by the user, and the sheet is placed between the guides 2A and 2B of the paper feed tray 2 by the user. Each of the guide 2A and the guide 2B includes a transmission-side width sensor 21A and a reception-side width sensor 21B. The transmission-side width sensor 21A is configured by an infrared LED that emits radiation with a spread. The receiving side width sensor 21B is configured by a photodiode. The guide width WG between the guide 2A and the guide 2B is set equal to the width of the sheet PP by the user, so that the guide width WG becomes equal to the width of the sheet PP. Infrared light is supplied from the width sensor 21A on the transmission side to the width sensor 21B on the reception side. A voltage having a magnitude inversely proportional to the guide width WG between the guide 2A and the guide 2B, that is, the width of the sheet PP is generated in the width sensor 21B on the receiving side.

  The reading unit 3 includes a transport mechanism and a reading mechanism inside. The reading unit 3 pulls the sheet placed on the paper feed tray 2 inside. The reading unit 3 conveys the drawn sheet from the paper feed tray 2 toward the paper discharge tray 4. The reading unit 3 reads an image of the conveyed sheet.

  The paper discharge tray 4 receives the sheet conveyed by the reading unit 3. The setting unit 5 has a power switch and various setting buttons. The display unit 6 is configured by a liquid crystal display. The display unit 6 can display an image read by the reading unit 3.

[Internal structure of image reading apparatus]
FIG. 2 is an explanatory diagram for explaining the internal structure of the image reading apparatus 1. As shown in FIG. 2, the image reading apparatus 1 includes a pickup roller 32, a separation pad 33, a detection unit 34, a feed roller 35, an image reading unit 36, a conveyance path 37, a discharge roller 38, and a control. Part 7.

  The pickup roller 32 pulls a plurality of sheets PP placed on the paper feed tray 2 into the image reading apparatus 1 by frictional force. The separation pad 33 separates the plurality of sheets PP into several sheets by frictional force. It is desirable that the plurality of sheets PP be separated into one sheet PP by a separation mechanism such as the separation pad 33. However, even in the presence of a separation mechanism such as the separation pad 33, there may be a case where several sheets PP are conveyed while being overlapped. Hereinafter, several sheets PP separated by the separation pad 33 are referred to as transported paper. The transported paper includes a sheet and attached paper attached to the sheet. That is, the transported paper transported in the reading unit 3 is composed of only one sheet, a sheet in which a plurality of sheets are overlapped, and an attached sheet attached to the sheet. There are cases of sheets.

  The detection unit 34 detects the number of sheets to be transported. The detection unit 34 is configured by an ultrasonic sensor. The detection unit 34 includes a transmission side sensor 34A and a reception side sensor 34B. The detection of the number of sheets by the detection unit 34 will be described in detail with reference to FIG. FIG. 3 is an explanatory diagram for explaining the detection of the number of sheets by the detection unit 34. FIG. 3A is a diagram illustrating the top surface of the transported paper FS. FIG. 3B is a diagram illustrating a side surface of the transported paper FS. FIG. 3C is a diagram illustrating an ultrasonic signal sg received by the receiving sensor 34B. Ultrasonic waves are sequentially supplied from the Z-axis direction to the transported paper FS by the transmission side sensor 34A. Since the transported paper FS is transported in the X-axis direction, ultrasonic waves are sequentially supplied from the Z-axis direction to the transported paper FS along the detection line DL shown in FIG. The ultrasonic waves supplied to the transported paper FS by the transmission side sensor 34A are attenuated mainly in accordance with the number of transported paper FS as shown in FIG. The receiving sensor 34B receives a signal sg proportional to the intensity of the attenuated ultrasonic wave. As shown in FIG. 3A, when two sheets SH are transported in an overlapping manner, the number of transported sheets FS in the overlapping portion DR is as follows. Is equivalent to 2 sheets. Therefore, when double feeding occurs as shown in FIGS. 3A and 3B, the ultrasonic wave supplied to the transported paper FS by the transmission side sensor 34A is transported as a single sheet SH. As compared with the case of FIG. 3, it is greatly attenuated as shown in FIG. The detection unit 34 in the present embodiment is an example of the detection unit of the present invention.

  As shown in (A) of FIG. 3, when the attached paper AS is attached to the sheet SH, as shown in (B) of FIG. 3, the ultrasonic wave is in a region where the attached paper AS is attached. It attenuates as shown in FIG. Therefore, as shown in FIGS. 4A and 4B, when the transported paper FS is one sheet SH and the attached paper AS, as shown in FIG. Ultrasound is detected. Therefore, as shown in FIG. 4, attenuated ultrasonic waves are detected even when no double feed occurs. Therefore, simply detecting the attenuated ultrasonic wave and determining the double feed may cause the sheet SH to be erroneously determined as the double feed when the attached sheet AS is attached.

  The feed roller 35 is driven by a motor (not shown) to transport the transported paper FS. The transported paper FS is transported in the transport path 37.

  The image reading unit 36 includes a pair of contact image sensors (Contact Image Sensor, hereinafter referred to as “CIS”) 36 </ b> A and 36 </ b> B that face each other across the conveyance path 37. The image reading unit 36 reads images on the front and back surfaces of the transported paper FS. In the present embodiment, among the images on the front and back surfaces of the transported paper FS, the image on the front surface of the transported paper FS is used for image processing and the like described below. The CIS 36A in the present embodiment is an example of the image reading unit of the present invention.

  The discharge roller 38 supplies the sheet PP conveyed in the conveyance path 37 to the paper discharge tray 4. The sheet PP supplied to the paper discharge tray 4 by the discharge roller 38 is stacked on the paper discharge tray 4.

  The control unit 7 includes a computer having a CPU, ROM, flash ROM, RAM, and the like.

[Electrical configuration of image reading apparatus]
The electrical configuration of the image reading apparatus 1 will be described with reference to FIG. FIG. 5 is a diagram illustrating an electrical configuration of the image reading apparatus 1. In FIG. 5, the control unit 7 is divided into a plurality of functional blocks for convenience of explanation. However, it is actually configured by a computer having a CPU, ROM, flash ROM, RAM, and the like.

  As illustrated in FIG. 5, the control unit 7 includes a sheet width determination unit 71, a sheet data storage unit 72, a sheet length determination unit 73, a data storage unit 74, a width determination unit 75, and a width determination unit 76. A recognition unit 77, an image processing unit 78, a length determination unit 79, a length determination unit 80, and a number determination unit 81.

  The sheet width determining unit 71 determines the sheet width of the sheet SH. Specifically, a voltage value inversely proportional to the distance between the guide 2A and the guide 2B is received from the width sensor 21B. The distance between the guide 2A and the guide 2B is substantially equal to the width of the sheet PP. Further, since the sheet PP is at least one sheet SH placed on the sheet feeding tray 2, the width of the sheet PP is substantially equal to the sheet width of the sheet SH. Therefore, the voltage value received from the width sensor 21B is inversely proportional to the sheet width of the sheet SH. The sheet width determining unit 71 receives the voltage value to determine the sheet width of the sheet SH. In this embodiment, “determining” means obtaining a specific numerical value based on the obtained data, and determining a specific numerical value from a judgment criterion such as a table based on the obtained data. Including both.

  The sheet data storage unit 72 stores data related to the sheet length and width of various sheets SH. FIG. 6 is an explanatory diagram for explaining the sheet width and sheet length data of various sheets SH stored in the sheet data storage unit 72. The sheet width and sheet length of the various sheets SH are stored in association with each other by the sheet data storage unit 72 as shown in FIG. The data of the sheet width and the sheet length of the various sheets SH shown in FIG. 6 is hereinafter referred to as “table”.

  The sheet length determination unit 73 determines the sheet length of the sheet SH. Specifically, the sheet length of the sheet SH based on the sheet width of the sheet SH determined by the sheet width determination unit 71 and the sheet width and sheet length data of the various sheets SH stored in the sheet data storage unit 72. To decide. The width sensors 21A and 21B, the sheet width determination unit 71, the sheet data storage unit 72, and the sheet length determination unit 73 in the present embodiment are examples of the first acquisition unit of the present invention. The width sensors 21A and 21B and the sheet width determination unit 71 in the present embodiment are an example of the third acquisition unit of the present invention.

  The data storage unit 74 stores the image data of the transported paper FS read by the image reading unit 36. Specifically, the data storage unit 74 stores the number of transported paper FS at each X coordinate position detected by the detection unit 34 and the image data of the transported paper FS at each X coordinate position in association with each other.

  The width determination unit 75 determines the width wf of the transported paper FS at the X coordinate position of the transported paper FS from the image of the transported paper FS. Specifically, the width wf of the transported paper FS is determined from the image data of the transported paper FS stored in the data storage unit 74 as shown in FIG. The width wf of the transported paper FS is determined for each X coordinate position of the transported paper FS as shown in FIG. Accordingly, as shown in FIG. 7B, the width wf of the transported paper FS is determined as the width Lf at the coordinate position X1. At the coordinate position X2, the width wf of the transported paper FS is determined as the width Lg. The image reading unit 36, the data storage unit 74, and the width determination unit 75 in the present embodiment are an example of a second acquisition unit of the present invention.

  The width determination unit 76 compares the width wf at each X coordinate position of the transported paper FS determined by the width determination unit 75 with the sheet width Lg of the sheet SH illustrated in FIG. 7 determined by the sheet width determination unit 71. To do. By this comparison, the width determination unit 76 determines whether or not the width wf at each X coordinate position is less than the sheet width Lg of the sheet SH. The width determination unit 76 in the present embodiment is an example of a second determination unit of the present invention.

  The recognition unit 77 recognizes a part of the image of the attached paper AS that protrudes in the transport direction from the image of the sheet SH among the images of the transported paper FS read by the image reading unit 36. In the present embodiment, the partial image of the attached paper AS is an image of the protruding portion PJ, which is a partial image of the attached paper AS shown in FIG. The protruding portion PJ is a portion where the attached paper AS protrudes from the edge of the sheet SH in the conveyance direction. The recognizing unit 77 recognizes the image portion of the transported paper FS, in which the width wf is determined to be less than the sheet width Lg of the sheet SH, as the image of the protruding portion PJ at each X coordinate position. To do. As shown in FIG. 7B, the width wf of the range from the X coordinate position XA to the X coordinate position XB is equal to the width Lg. The width wf of the range from the X coordinate position XB to the X coordinate position XC is equal to the width Lf. As shown in FIG. 7, the width Lg> the width Lf. Therefore, in this case, the recognition unit 77 recognizes an image in the range from the X coordinate position XB to the X coordinate position XC as an image of the protruding portion PJ. The recognition unit 77 in the present embodiment is an example of the recognition unit of the present invention.

  As illustrated in FIG. 8, the image processing unit 78 generates the image by deleting the image of the protruding portion PJ recognized by the recognition unit 77 from the image of the transported paper FS read by the image reading unit 36. An image GI is generated. Specifically, the image data of the protruding portion PJ is erased from the image data of the transported paper FS stored in the data storage unit 74. The image processing unit 78 deletes the image of the protruding portion PJ recognized by the recognition unit 77 at each X coordinate position of the transported paper FS from the image of the transported paper FS. The data of the generated image GI is stored in the data storage unit 74 in association with the data of the number of transported sheets FS at each X coordinate position. The image processing unit 78 in the present embodiment is an example of the image processing unit of the present invention.

  The length determination unit 79 determines the length La in the transport direction of the generated image GI. Specifically, the length La in the transport direction of the generated image GI is determined from the data of the generated image GI stored in the data storage unit 74. The length determination unit 79 in the present embodiment is an example of a first determination unit of the present invention.

  The length determination unit 80 compares the length La determined by the length determination unit 79 with the sheet length Lb determined by the sheet length determination unit 73. By this comparison, the length determination unit 80 determines whether or not the length La is larger than the length Lb. The length determination unit 80 in the present embodiment is an example of a first determination unit of the present invention.

  The number determination unit 81 determines whether or not the number of portions corresponding to the generated image GI of the transported paper FS at each X coordinate position is two or more. Specifically, the data storage unit 74 reads the number of portions corresponding to the generated image GI at each X coordinate position stored in association with the data of the generated image GI at each X coordinate position. It is determined whether the number of portions corresponding to the generated image GI at each read X coordinate position is two or more. By this determination, it is determined whether or not the number of portions corresponding to the generated image GI at each X coordinate position is two or more. The number determination unit 81 in the present embodiment is an example of a third determination unit of the present invention.

  The setting unit 5 supplies various setting signals to the control unit 7. The setting unit 5 has a power switch. When a power ON command is supplied from the power switch of the setting unit 5 to the control unit 7, the operation control of the image reading apparatus 1 starts. When a power-off command is supplied from the power switch of the setting unit 5 to the control unit 7, the operation control of the image reading apparatus 1 is finished.

  The display unit 6 receives various display data from the control unit 7. The various display data includes image data stored in the data storage unit 74 and determination result data from the control unit 7.

[Image reader operation control]
Hereinafter, the operation control of the image reading apparatus 1 will be described with reference to FIG. FIG. 9 is a flowchart showing operation control of the image reading apparatus 1. A series of operation control is executed by the CPU constituting the control unit 7.

  In the process illustrated in FIG. 9, first, an operation start command is supplied from the setting unit 5 to the control unit 7. When the operation start command is supplied, the operation of the image reading apparatus 1 is started. When the operation of the image reading apparatus 1 is started, the sheet width determination unit 71 determines the sheet width of the sheet SH from the guide width WG. (Step S1, hereinafter referred to as S1). When the sheet width of the sheet SH is determined, the sheet length of the sheet SH is determined by the sheet length determination unit 73 from the sheet width of the sheet SH and the table shown in FIG. 6 (S2). When the sheet length of the sheet SH is determined, the sheet PP is drawn into the reading unit 3 and the conveyance of the sheet PP is started (S3).

  When the conveyance of the sheet PP is started, it is determined whether the leading end of the transported paper FS is detected by the detection unit 34 (S4). Specifically, when the ultrasonic wave attenuated by the detection unit 34 is detected, it is determined that the leading edge of the transported paper FS has been detected.

  When it is determined that the leading edge of the transported paper FS is detected (S4: Yes), the image reading unit 36 starts reading an image (S5). If it is determined that the leading edge of the transported paper FS has not been detected (S4: No), the process returns to S4 to determine whether the leading edge of the transported paper FS has been detected. During image reading after S5, detection processing by the detection unit 34 is always performed in parallel. After S5, when the image is read by the image reading unit 36, the read image data is stored in the data storage unit 74. The ultrasonic signal sg detected by the detection unit 34 as shown in FIG. 4C is associated with the image data read by the image reading unit 36 and stored in the data storage unit 74.

  When the image reading is started, it is determined whether the trailing edge of the transported paper FS has been detected (S6). Specifically, it is determined whether the output sg of the detection unit 34 is equal to or greater than a predetermined value, that is, it is determined that there is no ultrasonic attenuation. If it is determined that the trailing edge of the transported paper FS has been detected (S6: Yes), image reading is stopped (S7). If it is determined that the trailing edge of the transported paper FS has not been detected (S6: No), the process returns to S6 to determine whether the trailing edge of the transported paper FS has been detected.

  When the image reading is stopped, the width determining unit 75 determines the width of the image of the transported paper FS at the coordinate position X (S8). In the first S8, the coordinate position X is the coordinate position XC in the case of the transported paper FS shown in FIG. As will be shown later, the coordinate position X is changed from the coordinate position XC to the coordinate position XA. Note that the coordinate position XA is the coordinate position XA of the trailing edge of the transported paper FS detected in S6. The coordinate position XC is the coordinate position XC of the leading edge of the transported paper FS detected in S4. When it is determined that the trailing edge of the transported paper FS is detected (S6: Yes), the coordinate position XA is stored in the data storage unit 74 in association with the image data. When it is determined that the leading edge of the transported paper FS is detected (S4: Yes), the coordinate position XC is associated with the image data and stored in the data storage unit 74.

  When the image width is determined, the width determination unit 76 determines whether or not the determined image width is equal to or greater than the sheet width (S9). That is, as shown in FIG. 7, it is determined whether or not the determined width wf is equal to or greater than the sheet width Lg.

  If it is determined that the image width is equal to or greater than the sheet width Lg (S9: Yes), it is determined whether or not the current coordinate position X is the last coordinate position X (S10). That is, in the case of the transported paper FS shown in FIG. 7, it is determined whether or not the current coordinate position X is the coordinate position XA. The coordinate position XA is acquired from the data storage unit 74. If it is determined that the image width is not equal to or greater than the sheet width (S9: No), the image processing unit 78 deletes the image data at the coordinate position X from the data storage unit 74 (S11). When the image data at the coordinate position X is deleted, the process proceeds to S10. If it is determined in S10 that the current coordinate position X is not the last coordinate position X (S10: No), the coordinate position X is changed to the next coordinate position X (S13). That is, the coordinate position X is changed from the current coordinate position X to the next coordinate position X in the negative X-axis direction.

  When the coordinate position X is changed to the next coordinate position X, the process returns to S8. When the process returns to S8, the width of the image is determined. If it is determined that the current coordinate position X is the last coordinate position X (S10: Yes), the process proceeds to S12. By the processes of S8, S9, S10, S11, and S13, it is determined whether or not the width of the image of the transported paper FS is equal to or larger than the sheet width at each X coordinate position. Through the processes of S8, S9, S10, S11, and S13, the image of the pop-out portion PJ is deleted, and the generated image GI is generated. When the process proceeds to S12, the length in the X-axis direction of the generated image GI generated by the processes of S8, S9, S10, S11, and S13, that is, the image length is determined by the length determination unit 79 (S12). When the image length is determined, the process proceeds to S14.

  When the process proceeds to S14, the length determination unit 80 determines whether the length of the generated image GI in the X-axis direction is larger than the sheet length (S14). If it is determined that the length of the generated image GI in the X-axis direction is greater than the sheet length (S14: Yes), “multiple feed occurrence” is displayed on the display unit 6 (S15). If it is determined that the length of the generated image GI in the X-axis direction is equal to or shorter than the sheet length (S14: No), the number determination unit 81 determines whether the number of generated images GI at each X coordinate position is two or more. Is determined (S16). If it is determined that the number of generated images GI at each X coordinate position is two or more (S16: Yes), “multiple feed occurrence” is displayed on the display unit 6 (S15). By displaying the determination result on the display unit 6, the user can know whether or not the sheets PP are separated one by one in the image reading apparatus 1 and normally conveyed.

  If “multiple feed occurrence” is displayed in S15, it is determined whether or not a stop command is supplied to the control unit 7 from the power switch of the setting unit 5 (S17). In S16, if it is determined that the number of the generated image GI at each X coordinate position is not two or more (S16: No), has a stop command been supplied from the power switch of the setting unit 5 to the control unit 7? It is determined whether or not (S17). If it is determined that the stop command is not supplied (S17: No), the process returns to S1. If it is determined that a stop command has been supplied (S19: Yes), all the processes shown in FIG. 9 are completed.

(Modification)
In the present embodiment, the recognition unit 77 jumps out a portion of the image of the transported paper FS that has been determined by the width determination unit 76 that the width wf is less than the sheet width Lg of the sheet SH at each X coordinate position. It was recognized as a PJ image. However, the present invention is not limited to this, and may be recognized as follows, for example. That is, first, the corner of the image of the conveyed paper is detected. The width between two corners in the Y-axis direction is determined. It is determined whether or not the determined width is the width of the sheet. This determination process may be determined based on, for example, whether or not the determined width is a width within a predetermined range including a pre-stored sheet width. An image having the same width as the width between two corners determined not to be the width of the sheet is recognized as an image of the protruding portion PJ. For example, you may recognize as follows. That is, first, in the Y-axis direction, the width between two ends extending along the transport direction of the transported paper from the end positioned on the outermost side of the read image is determined. It is determined whether or not the determined width is the width of the sheet. An image between two end portions determined not to be the width of the sheet is recognized as an image of the protruding portion PJ.

  In the present embodiment, the sheet length of the sheet SH is acquired by being determined based on the sheet width of the sheet SH and the table shown in FIG. However, the present invention is not limited to this. For example, the setting unit may include a paper type button, and the sheet length of the sheet may be acquired by pressing the paper type button by the user. Further, for example, the image reading apparatus may include a detection unit such as an ultrasonic sensor for detecting a sheet length, and the detection unit may acquire the sheet length before the image is read. Further, for example, the image reading apparatus 1 may include various interfaces, and the sheet length of the sheet may be acquired from a PC or a network via the interface.

  In the present embodiment, the sheet width of the sheet SH is acquired by detecting the guide width. However, the present invention is not limited to this. For example, the setting unit may include a paper type button, and the sheet width may be acquired by pressing the paper type button by the user. Further, for example, the image reading apparatus 1 may include various interfaces, and the sheet width may be acquired from a PC or a network via the interfaces.

  In the present embodiment, the detection unit 34 is configured by an ultrasonic sensor. However, the present invention is not limited to this. For example, an optical sensor composed of a light emitting element and a light receiving element, a displacement detection sensor that contacts both surfaces of the transported paper and is displaced according to the number of transported papers, and the like may be used.

  In the present embodiment, the image reading apparatus 1 is a sheet feed scanner. However, the image reading apparatus 1 is not limited to this, and may be, for example, a multifunction machine including an automatic document conveyance reading mechanism. In this case, the image reading apparatus includes an image forming unit for printing the read image other than the reading unit. For example, the image reading apparatus may be a FAX. In this case, the image reading apparatus includes a transmission unit that transmits the read image to another FAX or the like.

  In the present embodiment, the length determination unit 79 determines the conveyance length from the image. However, the length is not limited to this, and for example, the conveyance length is determined from a sensor that detects the presence or absence of paper and the feed amount of the conveyance motor. It may be determined.

  In the present embodiment, when the control unit 7 determines that double feeding has occurred, the display unit 6 displays “double feeding”. However, the present invention is not limited to this. For example, the image reading apparatus may include a notification unit including a buzzer or the like, and notification to the user may be made by voice or the like indicating that double feed has occurred. In this case, the notification unit may be controlled based on the double feed determination result of the control unit. For example, the image reading apparatus includes a detection unit and a separation unit on the downstream side of the image reading unit. When it is determined that double feeding has occurred, the sheets are further reliably separated one by one. As described above, a frictional force may be applied to the sheet. In this case, the separation unit may be controlled based on the double feed determination result of the control unit.

DESCRIPTION OF SYMBOLS 1 Image reading apparatus 21A, 21B Width sensor 34A, 34B Detection part 36A, 36B Image reading part 71 Sheet width determination part 73 Sheet length determination part 75 Width determination part 76 Width determination part 77 Recognition part 78 Image processing part 79 Length determination part 80 Length judgment part 81 Number judgment part

Claims (6)

An image reading device that reads an image of a sheet to be transported including a sheet and an attached sheet attached to the sheet,
A first acquisition unit that acquires a sheet length that is a length in the conveyance direction of the sheet;
An image reading unit that reads a transport image that is an image of the transported paper;
A recognizing unit for recognizing a projected image that is a partial image of the attached paper that is projected in the conveying direction from a sheet image that is an image of the sheet among the conveyed images read by the image reading unit;
An image processing unit that generates a generated image by deleting the pop-up image recognized by the recognition unit from the transport image read by the image reading unit;
A first determining unit that determines an image length that is a length of the generated image in the transport direction;
A first determination unit that determines whether the image length determined by the first determination unit is greater than the sheet length acquired by the first acquisition unit;
When the first determination unit determines that the image length is longer than the sheet length, the image reading apparatus determines that a double feed, which is a state where the sheets are overlapped and conveyed, has occurred. . A second acquisition unit that acquires a conveyance width that is a length in a direction intersecting the conveyance direction of the conveyed paper at each position of the conveyed paper in the conveyance direction;
A third acquisition unit that acquires a sheet width that is a length in a direction intersecting the conveyance direction of the sheet;
A second determination unit that determines whether or not the transport width at each position of the transported paper is less than the sheet width;
The recognizing unit extracts, from the sheet, a part of the transport image of the transported paper that is determined by the second determination unit to be less than the sheet width at each position of the transported paper. Recognizing as part of the pop-up image of the attached paper popping out in the transport direction,
The image processing unit deletes the pop-up image recognized at each position of the transported paper by the recognition unit from among the transported images read by the image reading unit. The image reading apparatus according to 1.   The image reading apparatus according to claim 2, wherein the second acquisition unit acquires the transport width by determining the transport width from the transport image read by the image reading unit. A detection unit that detects the number of sheets to be conveyed at each position of the sheet to be conveyed;
Of the number of sheets at each position of the transported paper detected by the detection unit, the number of sheets at each position in the transport direction of the portion of the transported paper corresponding to the generated image generated by the image processing unit. A third determination unit that determines whether or not there are two or more sheets,
The first determination unit determines that the image length is equal to or less than the sheet length, and the third determination unit determines that the number of the generated images at each position in the transport direction is two or more. The image reading apparatus according to claim 1, wherein it is determined that the double feeding has occurred. An image reading method used in an image reading apparatus including an image reading unit that reads a transported image that is an image of a transported paper including a sheet and attached paper attached to the sheet,
A first acquisition step of acquiring a sheet length that is a length of the sheet in the transport direction;
Recognizing a projected image that is an image of a part of the attached paper that protrudes in the transport direction from a sheet image that is an image of the sheet among the transported images of the transported paper read by the image reading unit. Steps,
An image processing step of generating a generated image by deleting the pop-up image recognized by the recognition step from the transport image read by the image reading unit;
A first determination step of determining an image length that is a length in the transport direction of the generated image;
A first determination step of determining whether or not the image length determined in the first determination step is greater than a sheet length that is a length in the transport direction of the sheet acquired in the first acquisition step; With
An image reading method, wherein when the image length is determined to be larger than the sheet length in the first determination step, it is determined that a double feed, which is a state where the sheets are conveyed while being overlapped, has occurred. . An image reading program used in an image reading apparatus including an image reading unit that reads a transport image that is an image of a transported paper including a sheet and an attached paper attached to the sheet,
A first acquisition step of acquiring a sheet length that is a length of the sheet in the transport direction;
A recognition step of recognizing a pop-up image that is an image of the attached paper that pops out in the transport direction from a sheet image that is an image of the sheet among the transport images of the transported paper read by the image reading unit;
An image processing step of generating a generated image by deleting the pop-up image recognized by the recognition step from the transport image read by the image reading unit;
A first determination step of determining an image length that is a length in the transport direction of the generated image;
A first determination step of determining whether or not the image length determined in the first determination step is greater than a sheet length that is a length in the transport direction of the sheet acquired in the first acquisition step; When the first determination step determines that the image length is greater than the sheet length, it is determined that a double feed that is a state in which the sheets are overlapped and conveyed has occurred,
An image reading program characterized in that these steps are realized by a computer.