JP6041792B2 - Sheet detection apparatus, image processing apparatus, and sheet detection method - Google Patents

Description

  The present invention relates to a technique for detecting a front end and a rear end of a sheet such as a document or printing paper conveyed in an image processing apparatus of an image forming apparatus or an image reading apparatus.

  In an image processing apparatus such as a multifunction machine or a copying machine, a sensor for detecting the presence or absence of a sheet such as a document to be read or printing paper is generally mounted (see Patent Document 1). Further, the size of the sheet in the conveyance direction is detected by applying the detection of the sheet by such a sensor. That is, when the front end and the rear end in the sheet conveyance direction pass through the detection area of the sensor, the front end and the rear end are detected using the change in the output signal of the sensor, and based on the detection timing thereof. The sheet size is detected.

Japanese Patent Laid-Open No. 11-202687

  In the conventional image processing apparatus, such detection of the front end and the rear end in the conveyance direction of the sheet is performed by a single sensor. However, in such a form, when a sheet with a binding hole in which a binding hole is formed on one side, such as a binder paper (loose leaf paper), is used as a printing paper, the trailing end in the sheet conveyance direction is erroneously detected, As a result, there is a problem that erroneous detection of the sheet size occurs.

  That is, even when the binding hole forming portion passes through the detection area of the single sensor, the sheet non-detection signal is output from the sensor in the same manner as when the trailing end of the conveyance direction passes through the detection area of the sensor. Is output. Therefore, the sheet non-detection signal is erroneously detected as the rear end in the transport direction, not the rear end in the transport direction of the sheet. As a result, the sheet size is calculated based on the erroneously detected detection timing of the trailing end of the conveyance direction, thereby causing an erroneous detection of the sheet size.

  The present invention has been made in view of such problems, and a purpose thereof is a sheet detection apparatus, an image processing apparatus, and a sheet that can appropriately detect the trailing end of a sheet with a binding hole to be conveyed. It is to provide a detection method.

  A sheet detection apparatus according to one aspect of the present invention includes first signal output means, second signal output means, and detection processing means. The first signal output means is relatively on a first scanning line parallel to the predetermined conveyance direction with respect to one side portion of both sides in a direction orthogonal to the conveyance direction of the conveyed sheet. The signal corresponding to the scanning is output by scanning. The second signal output means outputs a signal corresponding to the scanning by relatively scanning the second scanning line parallel to the predetermined first scanning line with respect to the sheet. The detection processing unit detects a trailing end of the sheet in the conveyance direction based on signals output from the first signal output unit and the second signal output unit.

  An image processing apparatus according to another aspect of the present invention includes the sheet detection apparatus.

  A sheet detection method according to another aspect of the present invention includes a first step, a second step, and a third step. The first step scans relatively on a first scanning line parallel to the predetermined conveyance direction with respect to one side portion of both sides of the conveyed sheet in a direction orthogonal to the conveyance direction. As a result, a signal corresponding to the scanning is output. The second step relatively scans a second scanning line parallel to the predetermined first scanning line with respect to the sheet, and outputs a signal corresponding to the scanning. In the third step, the trailing end of the sheet in the conveyance direction is detected based on the signals output in the first step and the second step, respectively.

  According to the present invention, it is possible to appropriately detect the rear end in the conveyance direction of the sheet with a binding hole to be conveyed.

1 is a schematic diagram showing an internal configuration of an embodiment of an image processing apparatus according to the present invention. 1 is a block diagram illustrating an example of an electrical configuration of an image processing apparatus. The figure which shows the relationship between the binding hole when the sheet | seat with a binding hole is conveyed, and the detection area (1st, 2nd scanning line) of a 1st and 2nd sheet sensor part. The figure which shows the output signal of a 1st and 2nd sheet | seat sensor part. Explanatory drawing of the size adjustment process of an image. The flowchart which shows the detection process of the sheet | seat with a binding hole by a control part.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, embodiment described below is only an example which actualized this invention, and does not limit the technical scope of this invention.

  First, a schematic configuration of the image processing apparatus 1 according to the embodiment of the present invention will be described. The image processing apparatus 1 is a multifunction machine having an image reading function, a facsimile function, an image forming function, and the like. As shown in FIGS. 1 and 2, the image processing apparatus 1 includes an image reading unit 2, a document cover 3, an automatic document feeder (hereinafter referred to as ADF) 4, an image forming unit 5, and an operation display unit. 6 (see FIG. 2), a paper feed cassette 7, a communication interface (I / F) unit 8 (see FIG. 2), and a control unit 9 (see FIG. 2) for controlling them. Note that the image processing apparatus 1 that is a multifunction peripheral is illustrated and described as an example of the image processing apparatus according to the present invention. However, the present invention is not limited to this, and for example, a printer, a facsimile apparatus, a copier, or a scanner apparatus may be used. This corresponds to the image processing apparatus according to the invention.

  The image reading unit 2 executes image reading processing for reading image data from a document. As shown in FIG. 1, the image reading unit 2 includes a contact glass 10, a reading unit 11, mirrors 12 and 13, an optical lens 14, a CCD (Charge Coupled Device) 15, and the like.

  The reading unit 11 includes an LED light source 16 and a mirror 17 and is configured to be movable in the sub-scanning direction 18 (left and right direction in FIG. 1) by a moving mechanism (not shown) using a driving motor such as a stepping motor. Yes. When the reading unit 11 is moved in the sub-scanning direction 18 by the drive motor, light emitted from the LED light source 16 toward the contact glass 10 provided on the upper surface of the image reading unit 2 is moved in the sub-scanning direction 18. Scanned.

  The mirror 17 reflects the reflected light reflected by the back surface of the document or the document cover 3 toward the mirror 12 when light is emitted from the LED light source 16. The light reflected by the mirror 17 is guided to the optical lens 14 by the mirrors 12 and 13. The optical lens 14 collects incident light and makes it incident on the CCD 15.

  The CCD 15 is a photoelectric conversion element that converts received light into an electrical signal (voltage) corresponding to the amount of light (intensity of luminance) and outputs it to the control unit 9. In the control unit 9, image data of the document is generated by performing image processing on the electrical signal from the CCD 15. In the present embodiment, an example in which the CCD 15 is used as an imaging device will be described. However, a contact image sensor (CIS: Contact Image Sensor) having a focal length shorter than that of the CCD 15 is used instead of the reading mechanism using the CCD 15. It is also possible to apply a reading mechanism.

  The image reading unit 2 is provided with a document cover 3 so as to be rotatable. When the document cover 3 is rotated, the contact glass 10 on the upper surface of the image reading unit 2 is opened and closed. The rotation support portion of the document cover 3 is provided with a cover open detection sensor (not shown) such as a limit switch. When the user opens the document cover 3 so as to read an image of the document, the cover is opened. The detection sensor is activated and the detection signal (cover open detection signal) is output to the control unit 9.

  Here, the reading of the document image by the image reading unit 2 is performed in the following procedure. First, the document is placed on the contact glass 10, and then the document cover 3 is closed. Thereafter, when an image reading instruction is input from the operation display unit 6, one line of light is sequentially emitted from the LED light source 16 while moving the reading unit 11 to the right in the sub-scanning direction 18. Then, reflected light from the back of the document or document cover 3 is guided to the CCD 15 via the mirrors 17, 12, 13 and the optical lens 14, and light amount data corresponding to the amount of light received by the CCD 15 is sequentially output to the control unit 9. Is done. When the light amount data in the entire area irradiated with light is obtained, the control unit 9 processes the light amount data to generate document image data from the light amount data. This image data is image data constituting a rectangular image.

  A document cover 3 is provided with an ADF 4. The ADF 4 sequentially conveys one or more originals set on the original setting unit 19 by a plurality of conveyance rollers so that the automatic original reading position determined on the contact glass 10 passes rightward in the sub-scanning direction 18. Move the document. When the document is moved by the ADF 4, the reading unit 11 is disposed below the automatic document reading position, and the image of the moving document is read by the reading unit 11 at this position. The document setting unit 19 is provided with a mechanical sheet sensor (not shown) capable of outputting a contact signal. When a document is set on the document setting unit 19, the sheet sensor is activated and detected. A signal (document detection signal) is output to the control unit 9.

  As shown in FIG. 1, the image forming unit 5 is based on image data read by the image reading unit 2 or a print job input from an information processing apparatus such as an external personal computer through a communication I / F unit 8. An electrophotographic image forming means for executing image forming processing (printing processing). Specifically, the image forming unit 5 includes a photosensitive drum 20, a charging unit 21, a developing unit 22, a toner container 23, a transfer roller 24, a charge removing unit 25, a fixing roller 26, a pressure roller 27, and the like. In this embodiment, the electrophotographic image forming unit 5 will be described as an example. However, the image forming unit 5 is not limited to the electrophotographic type, and may be an ink jet recording type or other than that. The recording method or the printing method may be used.

  In the image forming unit 5, image forming processing for the printing paper supplied from the paper feeding cassette 7 is performed according to the following procedure. First, when a print job including a print instruction is input through the communication I / F unit 8, the photosensitive drum 20 is uniformly charged to a predetermined potential by the charging unit 21. Next, light based on image data included in the print job is irradiated onto the surface of the photosensitive drum 20 by a laser scanner unit (LSU not shown). As a result, an electrostatic latent image is formed on the surface of the photosensitive drum 20. The electrostatic latent image on the photosensitive drum 20 is developed (visualized) as a toner image by the developing unit 22. The developing unit 22 is supplied with toner (developer) from the toner container 23. Subsequently, the toner image formed on the photosensitive drum 20 is transferred onto the printing paper by the transfer roller 24. Thereafter, the toner image transferred to the printing paper is heated and fused by the fixing roller 26 when the printing paper passes between the fixing roller 26 and the pressure roller 27 and is discharged. The electric potential of the photosensitive drum 20 is neutralized by the neutralization unit 25.

  As shown in FIG. 2, the communication I / F unit 8 is an interface that executes data communication with an external apparatus connected to the image processing apparatus 1 via a communication network such as the Internet or a LAN. The storage unit 28 includes a nonvolatile memory such as a hard disk drive (HDD).

  The operation display unit 6 includes a display unit 29 and an operation unit 30. The display unit 29 is configured by, for example, a color liquid crystal display, and displays various types of information to the user who operates the operation display unit 6. The operation unit 30 includes various push button keys disposed adjacent to the display unit 29, a touch panel sensor disposed on the display screen of the display unit 29, and the like, and various instructions are input by the user of the image processing apparatus 1. The When the user performs an operation on the operation display unit 6 in order to execute an image reading operation or an image forming operation, the operation signal is output from the operation display unit 6 to the control unit 9.

  The sheet detection unit 31 includes a first sheet sensor unit 32 and a second sheet sensor unit 33. The first sheet sensor unit 32 includes a reflective optical sensor 321 having a light emitter made of, for example, a light emitting diode and a light receiver made of, for example, a phototransistor. When a sheet is present in the detection region of the optical sensor 321, the light output from the light emitter is reflected by the sheet, and the reflected light is received by the light receiver. The light receiver outputs a signal corresponding to the amount of received light. The second sheet sensor unit 33 includes a reflective optical sensor 331 having the same configuration as the optical sensor 321.

  In the present embodiment, the optical sensors 321 and 331 of the first sheet sensor unit 32 and the second sheet sensor unit 33 are at a predetermined position slightly downstream from the position where the sheet is fed from the sheet feeding cassette 7 as shown in FIG. is set up.

  Then, the first sheet sensor unit 32 irradiates one point with detection light. The irradiation point of the detection light by the first sheet sensor unit 32 is a longitudinal direction (binding hole) of a sheet (hereinafter, referred to as a binding holed sheet) in which a plurality of binding holes H1 are formed on one side such as a binder sheet (loose leaf sheet). When the sheet is set face up so that (the arrangement direction of H1) coincides with the sheet conveyance direction, the position in the main scanning direction is a position that substantially coincides with the center position of the binding hole H1. The second sheet sensor unit 33 irradiates one point with detection light. The irradiation point of the detection light by the second sheet sensor unit 33 is an axis in which the sheet with binding holes extends in the conveyance direction so that the longitudinal direction of the sheets with binding holes (alignment direction of the binding holes H1) coincides with the conveyance direction of the sheets. Is set so that the position in the main scanning direction substantially coincides with the center position of the binding hole H1.

  Therefore, as shown in FIG. 3, the optical sensor 321 of the first sheet sensor unit 32, when the sheet is conveyed in the conveying direction A1 with the front side facing, detects light in a straight line parallel to the conveying direction A1. The sheet is irradiated. The linear area irradiated with the detection light is referred to as a first scanning line W1 (hatched area in FIG. 3). The first scanning line W1 is a line that substantially coincides with a straight line that connects the centers of the binding holes H1 when the binding hole-attached sheet is set in the sheet feeding cassette 7 in a face-up state. That is, in the present embodiment, when the sheet with the binding holes is set in the sheet feeding cassette 7 in the face-up state, the optical sensor 321 is arranged so that the first scanning line W1 by the optical sensor 321 coincides with the straight line. It is positioned.

  Further, the optical sensor 331 of the second sheet sensor unit 33, when the sheet with a binding hole is conveyed in the conveyance direction A1 with the axis extending in the conveyance direction rotated about the rotation axis and turned upside down, the conveyance direction A1. The detection light is applied to the sheet in a straight line parallel to the sheet. The linear region irradiated with the detection light is referred to as a second scanning line W2 (hatched region in FIG. 3). The second scanning line W2 is the center of the binding hole H1 when the sheet with the binding hole is set in the sheet feeding cassette 7 in a state where the sheet is rotated upside down about the axis extending in the conveyance direction and turned upside down. It is a line that roughly matches the straight line connecting That is, in the present embodiment, when the sheet with a binding hole is set in the paper feed cassette 7 in an inverted state, the optical sensor 331 is set so that the second scanning line W2 by the optical sensor 331 coincides with the straight line. Is positioned.

  As described above, in the present embodiment, the optical sensor 321 of the first sheet sensor unit 32 and the optical sensor 331 of the second sheet sensor unit 33 scan both sides in the direction orthogonal to the sheet conveyance direction A1. Therefore, when the sheet to be conveyed is a sheet with a binding hole, either the detection region of the first sheet sensor unit 32 or the second sheet sensor unit 33 is used regardless of whether the binding hole sheet is face up or face down. The binding hole H1 passes through the detection area.

  The first sheet sensor unit 32 includes an amplifier and a comparator (both not shown). The amplifier amplifies the light reception signal output from the light receiver of the optical sensor 321 with a predetermined amplification factor. The comparator compares the output signal of the amplifier with a predetermined threshold value, and outputs a signal indicating the comparison result. That is, the output signal of the comparator becomes HIGH when the output signal of the amplifier is larger than the threshold value, and becomes LOW when the output signal of the amplifier is smaller than the threshold value. An output signal indicating these comparison results is output to the control unit 9.

  Similar to the first sheet sensor unit 32, the second sheet sensor unit 33 also includes an amplifier and a comparator (both not shown). Since the functions of the amplifier and the comparator are the same as those of the amplifier and comparator of the first sheet sensor unit 32, description thereof is omitted.

  As will be described later, the control section 9 (sheet detection processing section 91 and sheet size detection processing section 92 described later) outputs the output signals output from the comparators of the first sheet sensor section 32 and the second sheet sensor section 33. Is used to detect the front and rear ends of the sheet in the conveying direction, and the sheet size. HIGH of the output signal corresponds to a sheet detection signal, and LOW of the output signal corresponds to a sheet non-detection signal. The first sheet sensor unit 32 corresponds to a first signal output unit, and the second sheet sensor unit 33 corresponds to a second signal output unit.

  The control unit 9 includes a CPU, a ROM, and a RAM. The CPU is a processor that executes various arithmetic processes. The ROM is a non-volatile storage unit in which information such as a control program for causing the CPU to execute various processes is stored in advance. The RAM is a volatile storage unit used as a temporary storage memory (working area) for various processes executed by the CPU. The control unit 9 controls the operation of each unit by the CPU executing a program stored in the ROM.

  The control unit 9 includes a sheet detection processing unit 91, a sheet size detection processing unit 92, a binding hole size detection processing unit 93, and an image processing unit 94 as shown in FIG. The sheet detection processing unit 91 corresponds to a first detection processing unit, the sheet size detection processing unit 92 corresponds to a second detection processing unit, the binding hole size detection unit 92 corresponds to a third detection processing unit, The image processing unit 38 corresponds to an image processing unit. The processing units 91 to 94 and the sheet detection unit 31 constitute a sheet detection apparatus.

  The sheet detection processing unit 91 includes a front end in the transport direction and a rear end in the transport direction in the transport direction based on signals output from the sheet detection unit 31 (the first sheet sensor unit 32 and the second sheet sensor unit 33). Is detected.

  Specifically, the sheet detection processing unit 91 determines that a sheet exists in the detection area when the output signals of the first sheet sensor unit 32 and the second sheet sensor unit 33 are HIGH. When the output signals of the first sheet sensor unit 32 and the second sheet sensor unit 33 are LOW, the sheet detection processing unit 91 determines that no sheet exists in the detection area.

  When the output signals of the first sheet sensor unit 32 and the second sheet sensor unit 33 both change from the LOW state to the HIGH state, the sheet detection processing unit 91 determines the sheet conveyance direction. It is determined that the front end has been detected.

The determination of the output signal are both HIGH state of the first sheet sensor 32 and the second sheet sensor unit 33, when the respective output signal transitions both to the state of LOW, and detects the conveying direction trailing end of the sheet To do. In the case of a normal sheet, the front end and the rear end in the sheet conveyance direction are detected by this method.

  When a sheet with a binding hole is conveyed face-up in the arrangement direction of the plurality of binding holes H1 from the sheet feeding cassette 7, the binding hole H1 serves as a detection area (hatching area in FIG. 3) of the first sheet sensor unit 32. pass.

  At this time, as shown in FIG. 4, while the sheet passes through the detection area, the first sheet sensor unit 32 outputs an output signal Q1. The output signal Q1 is a periodic signal in which HIGH and LOW are switched alternately according to the arrangement mode of the binding holes H1. That is, during the period when the binding hole H1 portion passes through the detection area of the first sheet sensor unit 32, the output signal Q1 of the first sheet sensor unit 32 is LOW, and the portion between the adjacent binding holes H1 passes. During this period, the output signal Q2 is HIGH. On the other hand, while the sheet passes through the detection area, the first sheet sensor unit 32 outputs an output signal Q2. This output signal Q2 is always HIGH while the sheet passes through the detection area.

  In this way, when the output signal Q2 of the second sheet sensor unit 33 is HIGH, the sheet detection processing unit 91 relates to whether the output signal Q1 of the first sheet sensor unit 32 is HIGH or LOW. No determination is made that the front end and the rear end in the transport direction of the sheet have been detected.

  That is, as shown by the arrow X1 in FIG. 4, the output signal Q2 of the second sheet sensor unit 33 is HIGH from the state where both the output signals of the first and second sheet sensor units 32 and 33 are HIGH. In addition, it is assumed that the output signal Q1 of the first sheet sensor unit 32 has transitioned to a LOW state. At this time, the sheet detection processing unit 91 does not determine that the trailing edge in the sheet conveyance direction has been detected.

  In addition, as indicated by an arrow X2 in FIG. 4, the first and first output signals Q2 from the second sheet sensor unit 33 become HIGH and the output signal Q1 from the first sheet sensor unit 32 becomes LOW. It is assumed that the output signals Q1 and Q1 of the two sheet sensor units 32 and 33 are both changed to a high state. At this time, the sheet detection processing unit 91 does not determine that the front end in the sheet conveyance direction has been detected. In addition, the dotted line in FIG. 4 shows the detection signal outside a sheet | seat.

  The detection of the front end and the rear end in the transport direction of the sheet in the state of being turned upside down with the axis extending in the transport direction as the rotation axis is performed by the output signals Q1 and Q2 output from the first and second sheet sensor units 31 and 32. Q1 is the reverse of the above case. In this case, when the output signal Q1 of the first sheet sensor unit 32 is HIGH, the sheet detection processing unit 91 determines whether the output signal Q2 of the second sheet sensor unit 33 is HIGH or LOW. It is not determined that the rear end in the transport direction is detected.

  As described above, the sheet detection processing unit 91 starts from the state in which both the output signals Q1 and Q2 of the first sheet sensor unit 32 and the second sheet sensor unit 33 are HIGH. Only when both the output signals Q1 and Q2 of the two-sheet sensor unit 33 are changed to a LOW state, it is determined that the trailing edge of the sheet conveyance direction has been detected. Further, the sheet detection processing unit 91 starts from the state in which both the output signals Q1 and Q2 of the first sheet sensor unit 32 and the second sheet sensor unit 33 are LOW, and thus the first sheet sensor unit 32 and the second sheet sensor. Only when both the output signals Q1 and Q2 of the unit 33 are changed to a state of being HIGH, it is determined that the front end of the sheet conveyance direction has been detected.

  The sheet size detection processing unit 92 determines the size (length) in the sheet conveyance direction based on the time from the detection timing of the front end of the sheet conveyance direction to the detection timing of the rear end of the conveyance direction and the conveyance speed of the sheet. L1 is detected. For example, when the time difference between the front end detection timing and the rear end detection timing is T1 (s) and the sheet conveyance speed is V1 (cm / s), the sheet size detection processing unit 92 performs the sheet conveyance direction. The size (length) L1 is calculated as L1 = V1 × T1.

  When the periodic signal is output from one sheet sensor between the detection timing of the front end in the conveyance direction of the sheet and the detection timing of the rear end in the conveyance direction, the binding hole size detection processing unit 93 The size (diameter) of the binding hole is detected based on the LOW output time included in the cycle and the sheet conveyance speed.

  For example, if the output time of LOW included in one cycle is T2 (s) and the sheet conveyance speed is V1 (cm / s), the binding hole size detection processing unit 93 sets the binding hole size L2 to L2 = V1. Calculated as xT2.

  As shown in FIG. 5B, the image processing unit 94 sets a print prohibition region R1 including the binding hole position on the sheet in the binding hole H1 detected by the binding hole size detection processing unit 93. Set based on size and position. For example, the image processing unit 94 prints an area from the scanning line of the sheet sensor in which the binding hole H1 is detected to a position that is separated inward in the main scanning direction by a length determined according to the size of the binding hole H1. It is set as the prohibited area R1.

  Then, the image processing unit 94 sets the region excluding the print prohibition region R1 as the print target region R2, and as shown in FIG. 5C, for example, an image read by the image reading unit 2 (image G1 in FIG. 5). ) Is generated as an image to be printed on the image forming unit 5.

  Next, a detection process of a sheet with a binding hole by the control unit 9 will be described. FIG. 6 is a flowchart of this detection process. This sheet detection process is executed, for example, when an instruction to copy an image of a document is input by the user. 6, steps S1, S2,... Represent processing procedure (step) numbers. Here, it is assumed that the sheet is set face up.

  As shown in FIG. 6, the sheet detection processing unit 91 determines whether the output signals Q1 and Q2 of the first sheet sensor unit 32 and the second sheet sensor unit 33 have both transitioned from the LOW state to the HIGH signal state. Is determined (step S1). If it is determined that the sheet has not changed (NO in step S1), the sheet detection processing unit 91 stands by. On the other hand, if the sheet detection processing unit 91 determines that the transition has occurred (YES in step S1), it determines that the front end of the sheet in the conveyance direction has been detected (the front end has passed the detection area) (step S2).

  Next, the sheet detection processing unit 91 determines whether or not the output signal Q1 of the first sheet sensor unit 32 has been switched from HIGH to LOW (step S3). As a result, when the sheet detection processing unit 91 determines that the sheet has been switched (YES in step S3), the sheet detection processing unit 91 starts timing by a timer (not shown) (step S4), and the output signals of the first and second sheet sensor units 32 and 33 It is determined whether both Q1 and Q2 are in a HIGH state (step S5). If the sheet detection processing unit 91 determines that both are not in the HIGH state (NO in step S5), it waits. On the other hand, when the sheet detection processing unit 91 determines that both are in the HIGH state (YES in step S5), the timing is stopped (step S6), and the output signal Q1 of the first and second sheet sensor units 32 and 33 is stopped. , Q2 are both determined to be in the LOW state (step S7). On the other hand, when the sheet detection processing unit 91 determines in step S3 that the sheet has not been switched (NO in step S3), the process of step S7 is skipped and the process of step S7 is executed. In this case, the detection process is for a normal sheet having no binding holes.

  In step S7, the sheet detection processing unit 91 determines whether or not the output signals Q1 and Q2 of the first and second sheet sensor units 32 and 33 have both transitioned to the LOW state. If the sheet detection processing unit 91 determines that there is no transition (NO in step S7), the process returns to step S3. On the other hand, if the sheet detection processing unit 91 determines that both have transitioned to the LOW state (YES in step S7), it determines that the trailing edge in the sheet conveyance direction has been detected (the trailing edge has passed the detection region) ( Step S8).

  Then, the sheet size detection processing unit 92 determines whether the sheet with the binding holes is based on the time from the detection timing of the front end in the conveyance direction of the sheet with binding holes to the detection timing of the rear end in the conveyance direction and the conveyance speed of the sheets. A size (length) L1 in the transport direction is detected. (Step S9). In this case, as the time from the detection timing at the front end in the conveyance direction of the sheet to the detection timing at the rear end in the conveyance direction, the time measured by a separate timer between steps S2 to S8 is used. Further, the binding hole size detection processing unit 93 performs the periodic change output from the first sheet sensor unit 32 between the detection timing of the front end in the conveyance direction of the sheet with binding holes and the detection timing of the rear end in the conveyance direction. The size (diameter) of the binding hole is detected based on the output time of LOW included in one cycle of the output signal Q1 to be performed and the conveyance speed of the sheet with the binding hole (step S10). The time measured by the timer during steps S4 to S6 is used as the time of one cycle.

  The image processing unit 94 sets the print prohibition region R1 including the position of the binding hole on the sheet with the binding hole based on the size and position of the binding hole H1 detected by the binding hole size detection processing unit 93. Set (step S11). Then, the image processing unit 94 sets the region excluding the print prohibition region R1 as the print target region R2, and for example, the image read by the image reading unit 2 (the image G1 in FIG. 5) has the size of the print target region R2. An image reduced as a whole so as to fit is generated as an image to be printed by the image forming unit 5 (step S12).

  As described above, in the image processing apparatus 1 according to the present embodiment, the conveyance direction predetermined with respect to one side portion of both side portions in the direction orthogonal to the conveyance direction in the sheet with binding holes to be conveyed. The first sheet sensor unit 32 outputs a signal corresponding to the scanning by relatively scanning the first scanning line L1 parallel to the first scanning line L1. Further, the image processing apparatus 1 responds to the scanning by relatively scanning the second scanning line L2 parallel to the first scanning line L1 predetermined with respect to the sheet with the binding holes. The second sheet sensor unit 33 is provided for outputting the received signal. The image processing apparatus 1 includes a sheet detection processing unit 91 that detects a trailing end of a sheet with a binding hole based on signals output from the first sheet sensor unit 32 and the second sheet sensor unit 33. Is provided.

  Specifically, the sheet detection processing unit 91 is output from the other sheet sensor when the output signal of one of the first sheet sensor unit 32 and the second sheet sensor unit 33 is HIGH. It is not determined that the trailing end in the conveyance direction of the sheet with a binding hole is detected regardless of the HIGH / LOW of the output signal Q.

  Accordingly, it is possible to avoid erroneously detecting the binding hole H1 and the trailing end of the binding hole-attached sheet in the conveyance direction. As a result, it is possible to prevent erroneous detection of the sheet size.

  Further, in the image processing apparatus 1 according to the present embodiment, the second side portion on the other side opposite to the first scanning line L1 among the both side portions in the direction orthogonal to the conveyance direction of the binding hole sheet. The second sheet sensor unit 33 is caused to scan the scanning line L2. Therefore, even when the sheet with a binding hole is rotated about an axis parallel to the conveyance direction and turned upside down, the rear end in the conveyance direction of the sheet with the binding hole can be accurately detected. However, in the present invention, the second scanning line L2 is not limited to the other side opposite to the first scanning line L1.

  In addition, when a sheet non-detection signal is periodically output from one of the first and second sheet sensor units 32 and 33 between the detection of the front end in the conveyance direction of the sheet with the binding hole and the detection of the rear end, Based on the output time in one cycle of the sheet non-detection signal, the size of the binding hole H1 is detected. Then, a print prohibition area based on the binding hole H1 is set in the sheet with binding holes, and an image whose size is adjusted with an area excluding the print prohibition area as a print target area is generated as an image to be printed by the printing unit. .

  As a result, even when the print sheet is a sheet with a binding hole, it is possible to appropriately print an image of the read document in a region excluding the binding hole portion without reducing the visibility of the image.

  In the embodiment, the reflection type optical sensor is used as the optical sensors 321 and 331. However, the present invention is not limited to this, and a transmission type optical sensor or a proximity sensor using magnetism may be used.

DESCRIPTION OF SYMBOLS 1 Image processing apparatus 5 Image formation part (printing means)
32 1st sheet sensor part (1st signal output means)
33 Second sheet sensor unit (second signal output means)
91 Sheet detection processing unit (first detection processing means)
92 Size detection processing unit (second detection processing means)
93 Binding hole size detection processing unit (third detection processing means)
94 Image processing unit (image processing means)

Claims (7)

The scanning is performed by relatively scanning the first scanning line parallel to the predetermined conveyance direction with respect to one side portion of both sides of the conveyed sheet in the direction orthogonal to the conveyance direction. First signal output means for outputting a corresponding signal;
A second signal output means for outputting a signal corresponding to the scanning by relatively scanning a second scanning line parallel to the first scanning line that is predetermined with respect to the sheet;
First detection processing means for detecting a trailing end of the sheet in the conveyance direction based on signals output from the first signal output means and the second signal output means;
Equipped with a,
The first detection processing means includes
A sheet non-detection signal from each of the first signal output means and the second signal output means from a first detection state in which a sheet detection signal is output from at least one of the first signal output means and the second signal output means. A sheet detection device that detects the trailing edge of the sheet in the conveyance direction based on switching to the second detection state in which is output . The sheet detection apparatus according to claim 1, wherein the first detection processing unit further detects a front end of the sheet in the conveyance direction based on switching from the second detection state to the first detection state . The first, based on the transport direction front end and the conveying direction trailing end is detected by the detection processing means, the sheet according to claim 2 in which the second further comprises detection processing means for detecting a size of the sheet in the transport direction Detection device. Any the second scanning line, of claims 1 to 3 and the first scan line of the both sides of the direction which is the scanning line in the other side of the opposite perpendicular to the conveying direction of the sheet The sheet detection apparatus according to claim 1.   An image processing apparatus comprising the sheet detection apparatus according to claim 1. The sheet detection apparatus according to claim 2 or 3,
Printing means for printing on the sheet;
The sheet non-detection signal is periodically from either of said first signal output means and the second signal output means during a period from the detection timing of the conveying direction front end of the sheet to the detection timing of the conveying direction trailing end Is output, the binding hole is determined to be formed in the sheet, and the size of the binding hole is detected based on the output time in one cycle of the sheet non-detection signal and the sheet conveyance speed. 3 detection processing means;
An image obtained by setting a print prohibition area based on the binding hole detected by the third detection processing unit on the sheet and adjusting the size of an area excluding the print prohibition area as a print target area as an image to be printed by the printing unit. Image processing means for generating
Images processing device Ru comprising a. The scanning is performed by relatively scanning the first scanning line parallel to the predetermined conveyance direction with respect to one side portion of both sides of the conveyed sheet in the direction orthogonal to the conveyance direction. A first step of outputting a corresponding signal;
A second step of outputting a signal corresponding to the scanning by relatively scanning the second scanning line parallel to the predetermined first scanning line with respect to the sheet;
A third step of detecting a trailing end of the sheet in the conveyance direction based on signals output in the first step and the second step,
Equipped with a,
The third step includes
Second detection in which a sheet non-detection signal is output in each of the first step and the second step from a first detection state in which a sheet detection signal is output in at least one of the first step and the second step. A sheet detection method for detecting a trailing end of the sheet in the conveyance direction based on switching to a state .

Images