JP2017118269A - Reading device and detection method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reading device which properly detects an original size regardless of an original color.SOLUTION: A predetermined position of a cover of a reading device is processed so that, when a light source irradiates a light to the predetermined position of the cover at a first irradiation angle and a second irradiation angle, a light amount of a reflection light received by a light reception part is different at each of the first irradiation angle and the second irradiation angle. On the basis of first reading data acquired by being irradiated the light at the first irradiation angle, and second reading data acquired by being irradiated at the second irradiation angle, the size of an original is detected.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a reading apparatus and a detection method for optically reading a document image.

  In general, an image reading apparatus used for a copying machine, an image scanner, or the like irradiates light toward a document that passes through or is placed on a contact glass as a document table, and receives reflected light. Scan the image on the original. The contact glass is made of transparent glass and is provided on the upper surface of the apparatus main body. Inside the apparatus main body below the contact glass, there are provided a light source for irradiating light toward the original, an image sensor for photoelectrically converting reflected light and taking it in as image data, and the like.

  The image reading apparatus has a function of automatically measuring the size of the document placed on the contact glass. As a method of measuring the document size, a method of measuring the document size by using a plurality of sensors arranged at a position corresponding to the document size, or a line sensor that performs a scanning operation for reading a document image is used. There is a way to measure. Japanese Patent Application Laid-Open No. 2004-228561 describes an image reading apparatus that receives reflected light emitted from a light source toward a document with a line sensor and determines the document size based on the output of the line sensor.

  A line sensor used for reading a document image captures reflected light from the document surface as white pixels. Therefore, in order to identify the edge of the document, it is necessary to image the periphery of the document as pixels other than white, for example, black pixels. The automatic measurement of the document size using the line sensor is executed, for example, before closing a document presser (platen cover or the like) provided to be openable and closable with respect to the contact glass.

  In the case of the image reading apparatus described in Patent Document 1, light is irradiated by a light irradiation unit (light source) having a length substantially the same as one side of the contact glass in order to determine the document size. When a document having a size shorter than one side of the contact glass is placed on the contact glass, there is a high possibility that light leaks from a region outside the document to the user side. As a result, the user may feel dazzled and feel uncomfortable, which may reduce work efficiency.

  In Patent Document 2, a specular sheet having a concave groove formed on a pressure plate is used so that read data of a portion without a document becomes black when the pressure plate is closed, and a document size is detected from a color difference from the document. A configuration that does not make the user feel glare due to the configuration is described.

JP-A-11-75025 JP-A-8-201933

  However, in Patent Document 2, when the original is black or the end of the original is black, there is no color difference between the original and non-original parts, and accurate original size detection is performed. I can't.

  An object of the present invention is to solve such conventional problems. In view of the above-described points, an object of the present invention is to provide a reading apparatus and a detection method that appropriately detect a document size in a state where a pressure plate is closed regardless of a document color.

  In order to solve the above-described problem, the reading apparatus according to the present invention switches the irradiation angle of the light to the reading object to the first irradiation angle and the second irradiation angle that is symmetric to the first irradiation angle. A light source capable of irradiating the object to be read; and a light receiving unit for receiving reflected light from the object to be read; a reading means for acquiring a document image placed on the document table; and covering the document table When the light source irradiates light at a predetermined position of the cover at the first irradiation angle and the second irradiation angle, the light receiving unit is configured for each of the first irradiation angle and the second irradiation angle. The first irradiation acquired by the reading unit in a state where the cover on which the predetermined portion is processed and the document on the document table are covered with the cover so that the amount of reflected light received is different. Obtained by irradiating light from the light source at an angle Detecting means for detecting the size of the document based on first read data and second read data acquired by irradiating light from the light source at the second irradiation angle. And

  According to the present invention, it is possible to appropriately detect the document size with the pressure plate closed, regardless of the document color.

1 is a diagram illustrating a schematic configuration of an image reading apparatus. It is a block diagram which shows the control structure of a reading unit. 1 is a perspective view of an image reading device. It is a figure for demonstrating the state of a read image. It is the figure which looked at the platen glass from the upper side. 6 is a flowchart illustrating document size detection processing. It is the figure which looked at the platen glass from the upper side. 6 is a flowchart illustrating document size detection processing.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The following embodiments do not limit the present invention according to the claims, and all combinations of features described in the embodiments are not necessarily essential to the solution means of the present invention. . The same constituent elements are denoted by the same reference numerals, and the description thereof is omitted.

[First Embodiment]
FIG. 1 is a diagram illustrating a schematic configuration of an image reading apparatus. An image reading apparatus 100 shown in FIG. 1 includes a scanner unit 1 and an ADF unit 6. The ADF unit 6 is an original document feeder that is connected at the end of the scanner unit 1 and configured to be openable and closable. The user opens the ADF unit 6 to place the document 5 on the document table glass 2, and the scanner unit 1 reads the document placed on the document table. The ADF unit 6 is provided with a document tray 7 (ADF paper feed tray). When a plurality of documents are placed on the document tray 7, the ADF unit 6 feeds the documents one by one inside, and the scanner unit 1 continuously reads the images of the documents. The scanner unit 1 irradiates light on a document using a reading unit 10 (reading unit) configured by a reading method such as a CCD or CIS, and receives reflected light from the document. Image data (read data) is generated by the scanner unit 1 generating a read signal by photoelectric conversion of reflected light.

  The reading unit 10 includes light sources 11 a and 11 b such as LEDs corresponding to each color, an optical lens 13, and an image sensor 12 as a light receiving unit, and a document table on the side opposite to the document 5 placement side. It is configured to be in close contact with the glass 2. The ADF unit 6 is provided with a white region original pressing plate 9 (hereinafter referred to as a pressure plate 9) at a position facing the reading region on the platen glass 2. Light from the light sources 11 a and 11 b of the reading unit 10 is reflected by the image sensor 12 after being reflected by the document 5 and the pressure plate 9 on the background of the document 5. The document 5 and the pressure plate 9 are objects to be read by the scanner unit 1.

  The light sources 11 a and 11 b illuminate the document at each predetermined irradiation angle with respect to the document table glass 2. The optical lens 13 is a lens array in which a plurality of Selfoc lenses (registered trademark) are arranged in an array. The image sensor 12 is composed of a plurality of photoelectric conversion elements and the like arranged in a line in a predetermined direction, and images the light guided by the optical lens 13. The arrangement direction of the plurality of photoelectric conversion elements corresponds to the main scanning direction that intersects the moving direction (sub-scanning direction) of the reading unit 10 indicated by an arrow in the drawing. Since the reading unit 10 is positioned on the lower surface of the reading glass 3, it is possible to read the surface of the document that is sequentially fed from the ADF unit 6 on one surface of the reading glass 3.

  In the present embodiment, it is assumed that the image sensor 12 is a CMOS sensor. The image data of the document read and generated by the image sensor 12 is stored in a storage unit such as a memory. A reading unit 10 configured as shown in FIG. 1 is mounted on a driving belt (not shown), and the driving force of a scanner motor such as a stepping motor or a DC motor is transmitted to the guide rail through the driving belt. Along the sub-scanning direction.

  The scanner unit 1 reads an image of the document 5 by electrically scanning the reading unit 10 in the main scanning direction while moving the reading unit 10 in the sub-scanning direction. Further, at the time of image reading, the reading unit 10 irradiates light to the white reference plate 4 provided at the end of the platen glass 2 and acquires a reference signal for performing shading correction from the reflected light.

  The ADF unit 6 feeds a plurality of documents placed on the document tray 7 with the surface facing upward from the uppermost document to the inside of the ADF unit 6 by a pickup roller. Inside the ADF unit 6, the sheet is conveyed to a reading position on the upper surface of the reading glass 3 via a registration roller and a conveying roller (not shown). Documents that have passed through the reading position are sequentially discharged onto the sheet discharge tray 8 with the document surface facing downward via the conveyance roller and the sheet discharge roller.

  FIG. 2 is a block diagram showing a control configuration of the reading unit 10. An electrical signal (read signal) output from each chip of the image sensor 12 is converted into digital data (image data) in an AFE (analog front end) 14. For example, the AFE 14 performs signal processing suitable for the order in which image processing is performed later, such as changing the order of A / D conversion by a multiplexer corresponding to each chip.

  The control unit 20 receives the data output from the AFE 14. The control unit 20 includes a light source control unit 13 that controls lighting of the light sources 11a and 11b. The light source control unit 13 determines the light amounts of the light sources 11 a and 11 b based on the luminance data acquired by reading the white reference plate 4. The light source control unit 13 controls the current value and supply time of the drive current supplied to the light sources 11a and 11b based on the determined light amount.

  The open / close detection unit 15 is, for example, a trigger switch configured in a hinge mechanism at the end of the scanner unit 1 that supports the open / close operation of the ADF unit 6 to which the pressure plate 9 is attached, and corresponds to the open / close angle of the ADF unit 6. Outputs signals such as ON / OFF. The control unit 20 determines the open / close state of the pressure plate 9 based on the output signal from the open / close detection unit 15. The sub-scanning direction size detection unit 16 is an optical sensor for detecting the size of the document in the sub-scanning direction, which will be described later with reference to FIG. The document size determination calculation unit 19 is based on the output data from the AFE 14, the output signal from the open / close detection unit 15, and the detection signal from the sub-scanning direction size detection unit 16, and the document size placed on the document table glass 2. Determine. The scanning drive unit 17 includes the above-described scanner motor and driving belt, and the scanning control unit 18 controls the scanning driving unit 17 to move the reading unit 10 in the sub-scanning direction.

  The image reading apparatus 100 illustrated in FIG. 1 may be connected to, for example, a recording apparatus (printer) that records an image on a recording medium. In that case, for example, the image reading apparatus 100 is mounted on a recording apparatus.

  FIG. 2B illustrates a block configuration of a control system when the image reading apparatus 100 is connected to the recording apparatus 213 and configured as an image forming apparatus 200 in which a scan function, a print function, a copy function, and the like are integrated. FIG. Such an image forming apparatus 200 includes an image reading apparatus 100, a recording apparatus 213, an image reading apparatus 100, and a controller unit 214 that comprehensively controls the recording apparatus 213.

  The controller unit 214 includes a CPU 201, ROM 202, RAM 203, HDD 204, external interface (IF) 207, scanner IF 205, and printer IF 206. The CPU 201 executes the functions of the image forming apparatus 200 by, for example, reading a program stored in the ROM 202 into the RAM 203 and executing it. For example, when a copy function execution instruction is received from the user, the CPU 201 instructs the image reading apparatus 100 to perform a reading operation via the scanner IF 205 and instructs the recording apparatus 213 to perform a recording operation via the printer IF 206. When the CPU 211 of the image reading apparatus 100 receives an instruction from the CPU 201 of the controller unit 214 via the IF 208, the CPU 211 performs overall control of the image reading apparatus 100 and executes a document reading operation. The external IF 207 can communicate with an external device via a network such as a LAN, and receives a scan job from an external host computer, for example.

  The control unit 20 of the image reading apparatus 100 includes a CPU 211 that communicates with the CPU 201 of the controller unit 214 and controls the image reading apparatus 100 in addition to the blocks shown in FIG. The control unit 20 includes a ROM 209 and a RAM 210, which are general-purpose ROMs and RAMs. The operation of the present embodiment is realized, for example, by the CPU 211 reading a program stored in the ROM 209 into the RAM 210 and executing it. The operation unit 212 of the image reading apparatus 100 includes a display showing device information, job processing status, and the like, a key for receiving an instruction operation from a user, and the like.

  The recording device 213 has a configuration corresponding to various recording methods such as an ink jet recording method and an electrophotographic method, and records an image on a recording medium. For example, the recording device 213 may perform a recording operation based on image data received from the outside by the external IF 207 or may perform a recording operation based on image data acquired by the reading operation of the image reading device 100.

  Although not shown in FIG. 2B, the controller unit 214 includes various functions of the image forming apparatus 200 such as an image processing unit for converting image data to be recorded into recording data that can be recorded by the recording device 213. The processing configuration necessary to execute is appropriately included.

  FIG. 3 is a perspective view of the image reading apparatus 100 and shows a state in which the platen 9 is opened and the document 5 is placed on the document table glass 2. FIG. 4 is a diagram for explaining the state of the read image in each case of the presence / absence of the document at the document size detection position in the present embodiment. In the present embodiment, as shown in FIG. 4, a groove (in a predetermined position of the pressure plate 9, which is vertically perforated on the upstream side in the sub-scanning direction and gently formed on the downstream side in the main scanning direction ( A document detection groove) 401 is formed. As shown in FIG. 4, the document detection grooves are formed to have different wall surface angles in the moving direction of the reading unit 10.

  As shown in the upper part of FIG. 4A, only the light source 11a upstream in the sub-scanning direction is turned on by the reading unit 10 having the light sources 11a and 11b on both sides in the sub-scanning direction centering on the reflected light incident part. Scan the document detection groove. As a result, the shadow of the document detection groove is read as an image, as shown in the lower part of FIG. On the other hand, as shown in the upper part of FIG. 4B, when only the light source 11b on the downstream side of the sub-scanning is turned on and the document detection groove is scanned in the reverse direction of FIG. 4A, the lower part of FIG. As shown, the image is read as an image without a shadow of the document detection groove.

  When the document 5 is placed on the document table glass 2, as shown in the middle part of FIG. 4A and the middle part of FIG. cover. As a result, as shown in the lower part of FIG. 4A and the lower part of FIG. 4B, the image of the document 5 is read.

  In the present embodiment, when the reading unit 10 moves in the direction shown in FIG. 4A, the light source 11a is turned on and the light source 11b is turned off. When the reading unit 10 moves in the direction shown in FIG. 4B, the light source 11a is turned off and the light source 11b is turned on. As shown in FIGS. 4A and 4B, the light source of the reading unit 10 is not limited to the configuration of FIGS. 4A and 4B as long as the irradiation angle of the light source can be switched.

  FIG. 5 is a view of the platen glass 2 of the image reading apparatus 100 as viewed from above. As shown in FIG. 5, each size document is placed so that the corner of the document abuts the reference point at the upper left corner. The document detection position in FIG. 5 is a position at which the main scanning size of all standard-size documents can be read, and the platen 9 has a document detection groove corresponding to the document detection position.

  The sub-scanning direction size detection units 16b and 16c correspond to the sub-scanning direction size detection unit 16 in FIG. 2 and are sensors for detecting the size of the document in the sub-scanning direction. The sub-scanning direction size detection unit 16b is installed at a position that becomes a boundary in the sub-scanning direction when an A4 size document and a B5R size document are placed. The sub-scanning direction size detector 16c is installed at a position that becomes a boundary in the sub-scanning direction when a B5R size document and an A4R size document are placed. The sub-scanning direction size detection units 16b and 16c are installed as a reflective optical sensor of CCD or CMOS type, for example, at the bottom of the image reading apparatus 100. For example, when the sub-scanning direction size detection unit 16 b does not detect reflected light, the size of the document 5 in the sub-scanning direction is determined as the sub-scanning direction size 501. Further, when the sub-scanning direction size detection unit 16b detects the reflected light and the sub-scanning direction size detection unit 16c does not detect the reflected light, the size of the document 5 in the sub-scanning direction is determined as the sub-scanning direction size 502. Is done. The size of the document 5 is specified based on the size determination result in the main scanning direction at the document detection position and the size determination result in the sub scanning direction by the sub scanning direction size detection units 16b and 16c.

  In FIG. 5, only the sub-scanning direction size detection units 16b and 16c are shown, and a position serving as a boundary in the sub-scanning direction when a document of A4R size and B4 size is placed, a document of B4 size and A3 size. It is not arranged at a position that becomes a boundary in the sub-scanning direction when placed. This is because, for example, when reflected light is detected by both the sub-scanning direction size detectors 16b and 16c, the document size corresponds to A4R, B4, or A3. This is because the determination can be made based on the size in the main scanning direction. However, the sensor is arranged at a position that becomes a boundary in the sub-scanning direction when an A4R size document and a B4 size document are placed, and at a position that becomes a boundary in the sub-scanning direction when a B4 size document and an A3 size document are placed. Thus, the size in the sub-scanning direction may be detected.

  FIG. 6 is a flowchart showing document size detection processing in the present embodiment. Each process of FIG. 6 is implement | achieved when CPU211 of the image reading apparatus 100 reads the program memorize | stored in ROM209 to RAM210, and performs it, for example. In step S <b> 601, the CPU 211 determines whether the pressure plate 9 is opened or closed by the open / close detection unit 15. If it is determined that the pressure plate 9 is open, the process proceeds to S602. If it is determined that the pressure plate 9 is closed, the process proceeds to S611.

  In step S <b> 602, the CPU 211 causes the scanning drive unit 17 to move the reading unit 10 to the document detection position illustrated in FIG. 5. In step S <b> 603, the CPU 211 determines whether the pressure plate 9 is opened or closed by the open / close detection unit 15. If it is determined that the pressure plate 9 is in a closed state, the process proceeds to S604. If it is determined that the pressure plate 9 is in an opened state, the process proceeds to S613. The case where the process proceeds to S604 is a case where the pressure plate 9 is closed by the user.

  In step S604, the CPU 211 turns on the light source 11a on the upstream side in the sub-scanning direction. In step S605, the CPU 211 scans the original detection groove formed near the original detection position of the pressure plate 9 as shown in the upper and middle stages of FIG. To do. At that time, as shown in the lower part of FIG. 4A, the portion where the document 5 is not placed is read as an image of the shadow of the document detection groove, and the portion where the document 5 is placed is the document. 5 is read.

  Thereafter, in step S606, the CPU 211 turns off the light source 11a and turns on the light source 11b. In step S607, the CPU 211 scans the document detection groove as shown in the upper and middle stages of FIG. At that time, as shown in the lower part of FIG. 4B, the portion where the document 5 is not placed is read as an image without the shadow of the document detection groove unlike the case where the light source 11a is turned on. The place where 5 is placed is read as an image of the document 5. After S607, in S608, the CPU 211 turns off the light source 11b.

  As shown in the lower part of FIG. 4 (a) and the lower part of FIG. 4 (b), in the image read in step S605 and the image read in step S607, there is a shadow of the original detection groove at a place where the original document 5 is not placed. A difference occurs as an image without a shadow. On the other hand, the portion where the document 5 is placed becomes an image of the document 5 in both cases, and no difference occurs. In step S <b> 609, the CPU 211 uses the document size determination calculation unit 19 to identify the boundary between the position where the difference has occurred due to the presence or absence of the shadow of the document detection groove and the position where the difference has not occurred as the end of the document in the main scanning direction. The size of the document 5 in the main scanning direction is determined. Thereafter, in S610, the CPU 211 returns the reading unit 10 to the home position by the scanning drive unit 17, and ends the processing of FIG. After the processing in FIG. 6 is completed, the CPU 211 determines from the size in the main scanning direction of the document 5 determined in S609 and the size in the sub scanning direction specified from the detection signals of the sub scanning direction size detection units 16b and 16c. Identify the document size. The CPU 211 stores the specified document size information in a storage area such as the RAM 210.

  Reference is again made to S601. If it is determined in S601 that the pressure plate 9 is in a closed state, in S611, the CPU 211 determines whether or not the user has pressed the copy button of the operation unit 212. Here, if it is determined that the copy button has not been pressed, the processing from S601 is repeated. On the other hand, if it is determined that the copy button has been pressed, the process proceeds to S612.

  In step S612, the CPU 211 determines whether the size information of the document 5 is stored in a storage area such as a RAM. Here, if it is determined that the size information of the document 5 is stored, the processing in FIG. 6 is terminated and the copying operation is performed. If it is determined in S612 that the size information of the document 5 is not stored, the process proceeds to S604, and the document size detection process after S604 is performed. For example, the size information of the document 5 stored in S609 is deleted after a predetermined time has elapsed, and the user opens the pressure plate 9, places the document 5, closes the pressure plate 9, and waits for a predetermined time. When the copy button is pressed after the elapse of time, the process proceeds to S604 as a result of the determination in S612.

  When it is determined in S603 that the pressure plate 9 is in the opened state, in S613, the CPU 211 determines whether or not the user has pressed the copy button of the operation unit 212. If it is determined that the copy button has not been pressed, the processing from S603 is repeated. On the other hand, if it is determined that the copy button is pressed, the document size is read while the pressure plate 9 remains open. Therefore, in S614, the CPU 211 determines that the document size is not determined. Is displayed on the operation unit 212 as a warning. After the process of S614, the process proceeds to S610, and then the process of FIG. When the process proceeds from S614 to S610, the size of the document 5 is not specified after the process of S610.

[Second Embodiment]
Next, a difference between the second embodiment and the first embodiment will be described.

  FIG. 7 is a view of the platen glass 2 of the image reading apparatus 100 as viewed from above. As shown in FIG. 7, each size document is placed so that the corner of the document abuts the reference point at the upper left corner. Unlike the case shown in FIG. 5, the platen 9 is also provided with document detection grooves at the document detection positions A, B, and C.

  As in the first embodiment, the document detection position A is a position where the main scanning size of all standard-size documents can be read. The document detection position B corresponds to a position that becomes a boundary in the sub-scanning direction when an A4 size document and a B5R size document are placed. The document detection position C corresponds to a position that becomes a boundary in the sub-scanning direction when a B5R size document and an A4R size document are placed. In this embodiment, the presence / absence of a document is determined by scanning the document presence / absence determination positions B and C closer to the reference point than the end of the B5R size document in the main scanning direction at the document detection positions B and C. Determine.

  In FIG. 7, only the document detection positions B and C are shown, and the B4 size and A3 size originals are placed at the boundary position in the sub-scanning direction when the A4R size and B4 size originals are placed. It is not configured at a position that becomes a boundary in the sub-scanning direction. For example, when it is determined that there is a document at both the document presence / absence determination positions B and C, the document size corresponds to A4R, B4, and A3. This is because the determination can be made based on the size in the main scanning direction. However, the document detection groove is formed at a position that becomes a boundary in the sub-scanning direction when an A4R size document and a B4 size document are placed, and at a position that becomes a boundary in the sub-scanning direction when a B4 size document and an A3 size document are placed. It may be configured so that the size in the sub-scanning direction can be detected.

  8A and 8B are flowcharts showing the document size detection process in the present embodiment. 8A and 8B is realized by the CPU 211 of the image reading apparatus 100 reading out a program stored in the ROM 209 to the RAM 210 and executing it, for example. In step S <b> 801, the CPU 211 determines whether the pressure plate 9 is opened or closed by the open / close detection unit 15. If it is determined that the pressure plate 9 is open, the process proceeds to S802. If it is determined that the pressure plate 9 is closed, the process proceeds to S812.

  In step S <b> 802, the CPU 211 causes the scanning drive unit 17 to move the reading unit 10 to the document detection position A illustrated in FIG. 7. In step S <b> 803, the CPU 211 determines whether the pressure plate 9 is opened or closed by the open / close detection unit 15. If it is determined that the pressure plate 9 is in the closed state, the process proceeds to S804. If it is determined that the pressure plate 9 is in the opened state, the process proceeds to S817. The case where the process proceeds to S804 is a case where the pressure plate 9 is closed by the user. In step S804, the CPU 211 performs document size detection processing.

  The document size detection process in S804 will be described with reference to the flowchart shown in FIG. In step S821, the CPU 211 turns on the light source 11a on the upstream side in the sub-scanning direction. In step S822, the CPU 211 scans a document detection groove configured in the main scanning direction near the document detection position of the pressure plate 9. At that time, as shown in the lower part of FIG. 4A, the portion where the document 5 is not placed is read as an image of the shadow of the document detection groove, and the portion where the document 5 is placed is the document. 5 is read.

  Thereafter, in step S823, the CPU 211 turns off the light source 11a and turns on the light source 11b. In step S824, the CPU 211 scans the document detection groove formed in the main scanning direction near the document detection position of the pressure plate 9. At that time, as shown in the lower part of FIG. 4B, the portion where the document 5 is not placed is read as an image without the shadow of the document detection groove unlike the case where the light source 11a is turned on. The place where 5 is placed is read as an image of the document 5. Thereafter, in S825, the CPU 211 turns off the light source 11b. After S825, the process of FIG. 8A is terminated, and the process returns to the process of FIG.

  There is a difference between the image read in S822 and the image read in S824 as an image with and without a shadow in the document detection groove at a position where the document 5 is not placed. On the other hand, the portion where the document 5 is placed becomes an image of the document 5 and no difference occurs. In step S <b> 805, the CPU 211 uses the document size determination calculation unit 19 to identify the boundary between the position where the difference has occurred due to the presence or absence of the shadow of the document detection groove and the position where no difference has occurred as the end of the document 5 in the main scanning direction. Then, the size of the document 5 in the main scanning direction is determined.

  Next, in S807, the CPU 211 moves the reading unit 10 to the document detection position B shown in FIG. 7 by the scanning drive unit 17, and performs document size detection processing in S807. In S807, the process of FIG. 8A described above is performed.

  In step S <b> 808, the CPU 211 determines the presence / absence of a document at the document presence / absence determination position B based on the document detection result in step S <b> 807. The CPU 211 determines the document presence / absence determination position when there is a difference between the image read in step S822 performed for the document presence / absence determination position B and the image read in step S824 as a shadowed and unshadowed image in the document detection groove. In B, it is determined that there is no document. On the other hand, if there is no difference between the images of the document 5, it is determined that there is a document at the document presence / absence determination position B.

  If it is determined in S808 that there is no original, in S809, the CPU 211 determines the size of the original 5 in the sub-scanning direction as the sub-scanning direction size 701 in FIG. In S810, the CPU 211 identifies the size of the document 5 from the size of the document 5 in the main scanning direction determined in S805 and the size of the document 5 in the sub-scanning direction determined in S809. The CPU 211 stores the specified document size information in a storage area such as the RAM 210. In step S811, the CPU 211 returns the reading unit 10 to the home position by the scan driving unit 17, and then ends the processing in FIG.

  If it is determined that there is a document in S808, in S814, the CPU 211 moves the reading unit 10 to the document detection position C shown in FIG. 7 by the scanning drive unit 17, and performs document size detection processing in S815. In S815, the process of FIG. 8A described above is performed.

  In step S816, the CPU 211 determines the presence / absence of a document at the document presence / absence determination position C based on the document detection result in step S815. The CPU 211 determines the presence / absence of the document when there is a difference between the image read in S822 performed at the document presence / absence determination position C and the image read in S824 as a shadowed and unshadowed image of the document detection groove. It is determined that there is no document at position C. On the other hand, when there is no difference between the images of the document 5, it is determined that there is a document at the document presence / absence determination position C.

  If it is determined in S816 that there is no document, the CPU 211 determines the size of the document 5 in the sub-scanning direction as the sub-scanning direction size 702 in FIG. In S810, the CPU 211 identifies the size of the document 5 from the size of the document 5 in the main scanning direction determined in S805 and the size of the document 5 in the sub-scanning direction determined in S816. In step S811, the CPU 211 returns the reading unit 10 to the home position by the scan driving unit 17, and then ends the processing in FIG.

  On the other hand, when it is determined that there is a document in S816, the size of the document 5 is any one of A4R, B4, and A3. In S810, the CPU 211 determines the size of the document 5 from the size in the main scanning direction determined in S805. Identify the size. The CPU 211 stores the specified document size information in a storage area such as the RAM 210.

  Again, refer to S801. If it is determined in S801 that the pressure plate 9 is in a closed state, in S812, the CPU 211 determines whether or not the user has pressed the copy button of the operation unit 212. If it is determined that the copy button has not been pressed, the processing from S801 is repeated. On the other hand, if it is determined that the copy button has been pressed, the process advances to step S813.

  In step S813, the CPU 211 determines whether the size information of the document 5 is stored in a storage area such as a RAM. Here, when it is determined that the size information of the document 5 is stored, the processing of FIG. 8 is ended and a copy operation is performed. If it is determined in S813 that the size information of the document 5 is not stored, the process proceeds to S804, and the document size detection process after S804 is performed. For example, the size information of the original 5 stored in S810 is deleted after a predetermined time has elapsed, and the user opens the pressure plate 9, places the original 5, closes the pressure plate 9, and waits for a predetermined time. When the copy button is pressed after the elapse of time, the process proceeds to S804 as a result of the determination in S813.

  If it is determined in S803 that the pressure plate 9 is in the opened state, in S817, the CPU 211 determines whether or not the user has pressed the copy button of the operation unit 212. If it is determined that the copy button has not been pressed, the processing from S803 is repeated. On the other hand, if it is determined that the copy button is pressed, the document size is read while the pressure plate 9 is kept open. In S818, the CPU 211 determines that the document size is not determined. Is displayed on the operation unit 212 as a warning. After the process of S818, the process proceeds to S811, and then the process of FIG.

  As described above, according to each embodiment, it is possible to accurately detect the document size without causing the user to feel glare and not depending on the color of the document.

  The document detection position shown in FIGS. 5 and 7 is not a document detection groove as described above, but has a groove shape as long as the light source 11a and the light source 11b are processed so as to make a difference in the image read by the reading unit 10. It is not necessary.

  Further, according to the embodiment described above, it is possible to detect the document size in the sub-scanning direction by providing the document detection grooves at the document presence / absence determination positions B and C in the sub-scanning direction as shown in FIG. A configuration in which one line is processed in the sub-scanning direction so that a difference between images read by the reading unit 10 between the light source 11a and the light source 11b may be used. For example, the document detection groove described in FIG. 4 may be provided continuously in the sub-scanning direction.

  1 Scanner unit: 6 ADF unit: 10 Reading unit: 11a, 11b Light source: 100 Image reading device: 211 CPU: 209 ROM: 210 RAM

Claims (7)

A light source capable of irradiating the reading object by switching the irradiation angle of the light to the reading object between a first irradiation angle and a second irradiation angle which is symmetric to the first irradiation angle; and from the reading object A light receiving unit that receives the reflected light of
Covering the document table, and when the light source irradiates light at a predetermined position of the cover at the first irradiation angle and the second irradiation angle, the first irradiation angle and the second irradiation angle, respectively. A cover in which the predetermined portion is processed so that the amount of reflected light received by the light receiving unit is different,
First reading data acquired by irradiating light from the light source at the first irradiation angle, acquired by the reading means in a state where the document on the document table is covered with the cover, and the second Detecting means for detecting the size of the document based on second read data obtained by irradiating light from the light source at an irradiation angle of
A reading apparatus comprising:   The reading apparatus according to claim 1, wherein the predetermined portion is a groove formed so as to straddle a plurality of size areas of the document. The reading unit is a line sensor, and the light receiving unit includes a plurality of image sensors arranged in a line,
The groove is a groove formed in the arrangement direction.
The reading apparatus according to claim 2. The light source irradiates light at the first irradiation angle and the second irradiation angle that are arranged symmetrically in a direction intersecting the arrangement direction with the light receiving unit as a center. A second light source,
The reading means irradiates light from the first light source to the predetermined portion while moving in the first moving direction to acquire the first read data, and the second opposite to the first moving direction. The second reading data is obtained by irradiating the predetermined portion with light from the second light source while moving in the moving direction of
The detecting means detects the size of the document based on the presence or absence of a shadow of the groove in the first read data and the second read data;
The reading device according to claim 1, wherein the reading device is a reading device. The reading unit turns off the second light source when moving in the first movement direction, and turns off the first light source when moving in the second movement direction;
The reading apparatus according to claim 4.   The reading apparatus according to claim 1, wherein the predetermined portion is configured to have different wall surface angles in the moving direction of the reading unit. A light source capable of irradiating the reading object by switching the irradiation angle of the light to the reading object between a first irradiation angle and a second irradiation angle which is symmetric to the first irradiation angle; and from the reading object A light receiving unit that receives the reflected light of
Covering the document table, and when the light source irradiates light at a predetermined position of the cover at the first irradiation angle and the second irradiation angle, the first irradiation angle and the second irradiation angle, respectively. A detection method that is executed in a reading device including a cover in which the predetermined portion is processed so that the amount of reflected light received by the light receiving unit is different,
First reading data acquired by irradiating light from the light source at the first irradiation angle, acquired by the reading means in a state where the document on the document table is covered with the cover, and the second A detection step of detecting the size of the document based on the second read data acquired by irradiating light from the light source at an irradiation angle of
A detection method characterized by comprising:

Images