JP2010063003A - Image reading apparatus and image forming apparatus - Google Patents

Abstract

By disposing a second reading unit below a document tray, it is possible to reduce a curved portion of a main conveyance path, to realize downsizing of the apparatus and high-speed reading processing, and addition and deletion of functions. To make it easy to do.
A scanner unit 70 is disposed below a main conveyance path 3 including a U-shaped curved portion 3A. In the space between the document tray 1 and the paper discharge tray 2 below the downstream end of the document tray 1, the CIS 20 as the second reading unit is disposed. The scanner unit 70 reads an image of the first surface of the document being conveyed in the main conveyance path 3A from the outside of the curved portion 3A. The CIS 20 reads an image of the second surface of the document being conveyed in the main conveyance path 3A at a position downstream of the curved portion 3A. There is no need to secure a space for placing the second reading means inside the curved portion 3A, and there is no problem in reducing the curvature of the curved portion 3A.
[Selection] Figure 2

Description

  The present invention relates to an image reading apparatus that reads images on both front and back sides of a sheet-like document placed in a stacked state, and an image forming apparatus including the image reading apparatus.

  2. Description of the Related Art As an image reading apparatus that reads an image of an original, there is an apparatus that can transport sheet-like originals placed in a stacked state one by one and read images on both sides of the original. This type of image reading apparatus is used not only by being connected to a network including a personal computer and a printer, but also mounted in an image forming apparatus such as a copying machine, a facsimile machine, or a multifunction machine.

  As a method for reading images on both sides of a document with an image reading apparatus, there are a document reversal reading method and a double-sided simultaneous reading method. In the original reversal reading method, a single reading unit is used, and after the reading unit reads an image on the first side of the original, the original with the front and back sides reversed is conveyed again to the reading unit, and the second side of the original is read. Read the image. In the double-sided simultaneous reading method, two reading units are used, and images on both the front and back sides of the document are read by each of the two reading units while the document is conveyed in one direction in the document conveyance path.

  As a conventional image reading apparatus, there is one that can selectively execute a document reversal reading method and a double-sided simultaneous reading method (see, for example, Patent Document 1). In this image reading apparatus, a main conveyance path including a U-shaped curved portion is formed between the document tray and the discharge tray, and the reading means is arranged from the branch position between the reading means and the discharge tray. A reverse conveyance path is formed between the upstream merging position. The first reading unit of the reduction optical system suitable for high-quality reading processing is arranged outside the curved part, and the second reading unit (CIS) of the same-magnification optical system suitable for miniaturization is arranged inside the curved part. is doing.

When outputting monochrome read data, the first reading unit reads the image on the first side of the document being conveyed in the main conveyance path in one direction, and the second reading unit reads the image on the second side. When outputting color reading data, after reading the image on the first side of the document being conveyed in the main conveyance path with the first reading means, the document is reversed on the front and back surfaces in the reverse conveyance path, and the main conveyance is performed. Returning to the path, the image on the second side of the document is read by the first reading means.
JP 2004-15299 A

  However, since the conventional image reading apparatus described in Patent Document 1 has the second reading unit disposed inside the range surrounded by the U-shaped curved portion in the main conveyance path and the reverse conveyance path, The curvature of the curved portion cannot be reduced. For this reason, not only the request for downsizing of the apparatus cannot be satisfied, but also when the image of the document is read by the document reversal reading method, it is possible to increase the conveyance time and meet the request for a high-speed reading process. Can not. Moreover, it is difficult to attach and detach the second transport means, and it is difficult to add or delete functions.

  The object of the present invention is to dispose the second reading means below the document tray so that the curved portion of the main transport path can be reduced, and the apparatus can be reduced in size and read processing speed can be increased. An object of the present invention is to provide an original reading apparatus and an image forming apparatus that can be easily added or deleted.

  The image reading apparatus of the present invention includes a document tray, a paper discharge tray, a main conveyance path, a first reading unit, and a second reading unit. The document tray stores documents before image reading processing. The paper discharge tray is disposed below the document tray with a space between the document tray and stores the document after the image reading process. The main conveyance path is formed between the document tray and the document discharge tray, includes a U-shaped curved portion, and passes below the end of the document tray on the main conveyance path side on the downstream side of the curved portion. The first reading unit reads an image on the first surface of the document being conveyed in the conveyance path from the outside of the bending portion. The second reading unit reads an image on the second surface of the document being conveyed below the end on the main conveyance path side in the document tray.

  In this configuration, the second reading means for reading the image on the second side of the document at the time of simultaneous duplex reading is arranged below the end on the main transport path side in the document tray. Since it is not necessary to provide a space for arranging the second reading means inside the curved portion of the main conveyance path, it does not hinder the reduction of the curvature of the curved portion. A space is provided below the document tray with the paper discharge tray, and the second reading unit is attached to and detached from the lower side of the main tray in the document tray without interfering with other components. .

  This configuration can also be applied to an image reading apparatus that includes a reverse conveyance path as well as a main conveyance path. The reverse conveyance path is between a branch position formed between the arrangement position of the first reading means and the arrangement position of the second reading means in the main conveyance path and a joining position formed on the upstream side of the first reading means. Then, the document with the front and rear ends reversed is conveyed. It is not necessary to provide a space for arranging the second reading means inside the range surrounded by the curved portion of the main conveyance path and the reverse conveyance path, and for performing both-sided simultaneous reading and document reverse reading alternatively. The conveyance path can be made small, and the apparatus can be downsized and the reading process can be speeded up.

  The second reading unit is preferably disposed integrally on the bottom surface of the document tray. By replacing the document tray, it is possible to easily add and delete the double-sided simultaneous reading function using the second reading unit.

  A shading correction plate for correcting the shading of the second reading unit and a discharge member for discharging the document to the discharge tray at a position facing the second reading unit across the main conveyance path, and the document to the discharge tray It is preferable that the guide member to be guided is detachably provided integrally. Necessary members can be easily attached and detached according to the presence or absence of the second reading means.

  The second reading unit preferably uses an equal magnification optical system sensor. It is possible to reduce the size of the entire apparatus by reducing the space of the second reading means below the end on the main transport path side in the document tray.

  It is preferable that a cooling fan for exhausting air on the second reading means side to a space between the document tray and the discharge tray is provided on the bottom surface of the document tray. By discharging the heat generated by the second reading unit to the space between the document tray and the paper discharge tray, the second reading unit can be efficiently cooled.

  According to the present invention, by arranging the second reading means below the document tray, the curved portion of the main conveyance path can be reduced, the apparatus can be downsized and the reading process can be speeded up, and the function can be improved. Addition and deletion can be easily performed.

  An image forming apparatus including an image reading apparatus according to an embodiment of the present invention will be described below with reference to the drawings.

  FIG. 1 is a schematic front sectional view of an image forming apparatus provided with the image reading apparatus of the present invention. The image forming apparatus 100 forms a multicolor or single color image on a predetermined sheet (recording medium) based on image data read from a document. For this reason, the image forming apparatus 100 has an image reading device 120 mounted on the top of the main body, and includes an image forming unit 110 and a paper feeding unit 130 therein.

  The image reading device 120 includes a scanner unit 70, a document table 71, and an automatic document feeder 72. Details of the image reading device 120 will be described later.

  The image forming unit 110 includes an intermediate transfer belt unit 40, image forming stations 30A to 30D, a secondary transfer unit 50, an exposure unit 60, and a fixing unit 70. In the intermediate transfer belt unit 40, an intermediate transfer belt 41, which is an endless belt, is rotatably stretched by a driving roller 42, a driven roller 43, and the like.

  The image forming stations 30 </ b> A to 30 </ b> D perform electrophotographic image formation using developers of black, cyan, magenta, and yellow, respectively. For example, in the image forming station 30A, a charging device 32A, a developing device 33A, and a primary transfer device 34A are arranged around the photosensitive drum 31A. The image forming stations 30B3 to 30D are configured in the same manner as the image forming station 30A.

  The exposure unit 60 includes a semiconductor laser (not shown), a polygon mirror 61, an fθ lens 62, a mirror 63, and the like. The exposure unit 60 drives the semiconductor laser based on the image data of each color of black, cyan, magenta, and yellow read by the image reading device 120, and distributes the laser light of each color to the image forming stations 30B3 to 30D. The exposure unit 60 may use a light source other than a semiconductor laser such as an LED array driven based on image data.

  For example, in the image forming station 30A, the peripheral surface of the photosensitive drum 31A is uniformly charged by the charger 32A, and then exposed with laser light based on black image data distributed from the exposure unit 60. As a result, an electrostatic latent image based on the black image data is formed on the peripheral surface of the photosensitive drum 31A. Next, black developer is supplied from the developing device 33A to the peripheral surface of the photosensitive drum 31A, and the electrostatic latent image is visualized as a black toner image. The toner image formed on the peripheral surface of the photosensitive drum 31A is transferred to the surface of the intermediate transfer belt 41 by the primary transfer unit 34A.

  At the time of color image formation, the image forming stations 30B to 30D perform the same processing as the image forming station 30A for each color of cyan, magenta, and yellow. Black, cyan, magenta, and yellow toner images are superimposed on the surface of the intermediate transfer belt 40.

  The paper feed unit 130 includes a paper feed cassette 81, a manual feed tray 82, a paper main transport path 83, and a paper sub transport path 84. The paper feed cassette 81 stores a plurality of sheets of sizes and types that are relatively frequently used. On the manual feed tray 82, sheets of a size and type that are relatively infrequently used are placed.

  The paper main transport path 83 is formed between the paper feed cassette 81 and the manual feed tray 82, between the intermediate transfer belt 40 and the secondary transfer unit 50, and between the fixing unit 70 and the paper discharge unit 90. . The secondary transfer unit 50 transfers the toner image carried on the surface of the intermediate transfer belt onto a sheet. The fixing unit 70 heats and pressurizes the paper on which the toner image is transferred, and fixes the toner image on the paper.

  The sheet sub-transport path 84 is formed between the position where the fixing unit 70 passes in the sheet main transport path 83 and the position where the paper discharge roller 91 is disposed and the upstream side where the secondary transfer unit 50 is disposed. . When forming an image on both sides of the sheet, the sheet sub-transport path 84 is configured to transfer the sheet on which the front and rear ends are reversed by the sheet discharge roller 91 after the image is formed on the first side and passes through the fixing unit 70. 40 and the secondary transfer unit 50.

  FIG. 2 is a schematic front sectional view of an image reading apparatus which is an example of an embodiment of the present invention. The image reading device 120 includes a scanner unit 70, a document table 71, and an automatic document feeder 72, and reads images on both the front and back sides of the document by either the document reversal reading method or the double-sided simultaneous reading method.

  The scanner unit 70 is a first reading unit according to the present invention. As an example, the scanner unit 70 is a reduction optical system sensor including a light source 70A, mirrors 70B to 70D, a CCD 70E, and a lens 70F, and can read an image with high accuracy. The document table 71 is made of hard plate glass, and is attached to the upper surface of the main body of the image forming apparatus 100.

  When the scanner unit 70 reads an image of a document placed on the document table 71, the scanner unit 70 moves the light source 70A and the mirrors 70B to 70D in the horizontal direction, and guides the image on the lower surface of the document to the CCD 70E via the lens 70F. At this time, the light source 70A and the mirror 70B move at a half speed with respect to the mirrors 70C and 70D, and the optical path length from the image surface of the document to the CCD 70E is kept constant.

  The automatic document feeder 72 is rotatably supported on the back side of the upper surface of the main body of the image forming apparatus 100. When an operator manually places a document on the document table 71, the automatic document feeder 72 is rotated to open and close the upper surface of the document table 71.

  The automatic document feeder 72 includes a document tray 1 for storing documents before image reading, and a paper discharge tray 2 for storing documents after image reading. The paper discharge tray 2 is arranged below the document tray 1 with a predetermined space between the bottom surface of the document tray 1.

  Inside the automatic document feeder 72, there is a main conveyance path 3 including a substantially U-shaped curved portion 3A between the document tray 1 and the paper discharge tray 2 via a position facing the sub-original table 71A. Is formed.

  A branch position 3B is formed in the main transport path 3 between the position where the sub-original table 71A is disposed and the paper discharge tray 2. The main tray 1 and the sub-original table 71A are located in the main transport path 3. A merging position 3C is formed with the position where the A reverse conveyance path 8 is formed between the branch position 3B and the merge position 3C. A switching claw 9 is swingably disposed at the branch position 3B. The switching claw 9 selects either the direction from the arrangement position of the sub platen 71A in the main conveyance path 3 toward the arrangement position of the conveyance roller 7D or the direction from the arrangement position of the conveyance roller 7D to the sub conveyance path 8. Open.

  In the main conveyance path 3, a pickup roller 4, a feeding roller 5, a separating roller 6, conveyance roller pairs 7A to 7D, and a discharge roller pair 10 are rotatably arranged. The pickup roller 4 contacts the uppermost surface of the document placed on the document tray 1 while rotating clockwise in the drawing. The feeding roller 5 and the separating roller 6 rotate in the clockwise direction in the drawing to guide only the topmost document into the main conveyance path 3. The conveyance roller pairs 7 </ b> A to 7 </ b> C convey the document guided into the main conveyance path 3 toward the sheet discharge tray 2. The pair of transport rollers 7D and the pair of paper discharge rollers 10 are driven to rotate in both forward and reverse directions. The originals are discharged to the paper discharge tray 2 during normal rotation, and the originals are placed in the sub-transport path 8 with the front and rear ends reversed during reverse rotation. Lead.

  A contact-type image sensor (hereinafter referred to as CIS) 20 that is a 1 × magnification optical system sensor is located on the upper side and a shading correction plate 25 is located on the lower side across the conveyance roller 7D and the discharge roller pair 10 in the main conveyance path 3. Each is arranged on the side. The CIS 20 is the second reading means of the present invention, and includes a light source 21, a rod-shaped lens 22, and a reading element 23, and can read an image at high speed.

  As an example, the CIS 20 is detachably mounted on the bottom surface of the end of the document tray 1 on the main conveyance path 3 side. The CIS 20 may be disposed below the end of the document tray 1 on the main conveyance path 3 side, and is not necessarily attached to the bottom surface of the document tray 1 in a detachable manner.

  On the bottom surface of the document tray 1, a cooling fan 11 is disposed on the downstream side of the CIS 20 in the document discharge direction from the main semi-lie path 3 to the discharge tray 2. The cooling fan 11 can discharge the heat generated in the CIS 20 to the space between the document tray 1 and the paper discharge tray 2 to effectively cool the CIS 20.

  The second reading means of the present invention is not limited to the CIS, and any sensor can be used on the condition that it can be arranged below the end of the document tray 1 on the main conveyance path 3 side.

  The shading correction plate 25 is fixed to the upper surface of the support base 27. The support table 27 is supported by the conveyance guide 24 via a spring 26. The spring 26 urges the support base 27 upward. The conveyance guide 24 constitutes a part of the main conveyance path 3. The conveyance guide 24 is a guide member of the present invention, and is detachably attached to the end of the discharge tray 2 on the main conveyance path 3 side integrally with the shading correction plate 25, the spring 26, and the support base 27. .

  The scanner unit 70 positions the light source 70A and the mirror 70B to face the sub-original platen 71A when reading an image only from the surface of the original (the upper surface of the original placed on the original tray 1) conveyed by the automatic original conveying device 72. The image of the document passing over the light source 70A is guided to the CCD 70E.

  Since the CIS 20 is disposed downstream of the curved portion in the main transport path 3 and below the end of the document tray 1 on the main transport path 3 side, the CIS 20 is disposed inside the curved portion 3A of the main transport path 3. It is not necessary to provide a space for arranging It is not hindered to reduce the curvature of the curved portion 3A, and the automatic document feeder 72 can be downsized.

  FIGS. 3A to 3F are cross-sectional views illustrating a document conveyance state in the reading process of the double-sided simultaneous reading method in the image reading apparatus 120. During the reading process of the double-sided simultaneous reading method, the image reading device 120 transfers the document once in the automatic document transport device 72 from the document tray 1 to the discharge tray 2 via the main transport path 3. Read images from both front and back sides.

  When a plurality of documents 200 are placed on the document tray 1 of the automatic document feeder 72, and the image forming apparatus 100 is instructed to copy the images on both sides of the document onto a sheet as a monochrome image, the image forming apparatus 100 A double-sided simultaneous reading start command is transmitted to the image reading device 120.

  Even when the image forming apparatus 120 is instructed to transmit the images on both sides of the document as monochrome image data to an apparatus such as a PC or a facsimile apparatus, the image forming apparatus 100 starts the double-sided simultaneous reading to the image reading apparatus 120. Send a command.

  Upon receiving the double-sided simultaneous reading start command, the image reading device 120 starts to rotate the rollers 4, 5, 6 and the roller pairs 7A to 7D, 10 of the automatic document feeder 72 as shown in FIG. The pickup roller 4 is brought into contact with the uppermost surface of the document 200. As a result, as shown in FIG. 3B, the uppermost sheet 201 of the plurality of documents 200 placed on the document tray 1 passes between the feeding roller 5 and the separating roller 6 and is mainly conveyed. Guided into the road 3.

  As shown in FIG. 3C, the image reading device 120 starts reading an image on the first surface of the original 201 by the scanner unit 70 at the timing when the leading edge of the paper 201 reaches the arrangement position of the sub original table 71A. . As shown in FIG. 3D, the automatic document feeder 72 swings the switching claw 9 upward to open the direction from the position where the sub document table 71A is disposed toward the paper discharge tray 2. As shown in FIG. 3E, the document 201 is conveyed from the branch position 3B toward the arrangement position of the conveyance roller pair 7D and the discharge roller pair 10.

  The pickup roller 4 stops rotating at any timing from when the leading edge of the document 201 reaches the conveying roller pair 7 </ b> A until the trailing edge of the document 201 passes through the pickup roller 4. The pickup roller 4 resumes rotation at a timing when a predetermined time has elapsed since the trailing edge of the document 201 has passed through the pickup roller 4, and a predetermined sheet interval is provided between the pickup roller 4 and the first document 201. The second original 202 is guided into the main conveyance path 3.

  The image reading device 120 starts reading an image on the second surface of the document 201 by the CIS 20 at a timing when the leading end of the document 201 reaches the arrangement position of the CIS 20. As shown in FIG. 3F, the document 201 is read by the CIS 20 while the original 201 is being conveyed toward the paper discharge tray 2 by the rotation of the conveyance roller pair 7D and the paper discharge roller pair 10. . During this time, reading of the image on the first surface of the original 202 by the scanner unit 70 is started at the timing when the leading edge of the original 202 reaches the sub-original table 71A.

  As described above, during simultaneous reading on both sides, the scanner unit 70 reads an image on the first side of the document while the document is being transported from the document tray 1 to the paper discharge tray 2 via the main transport path 3, and is read by the CIS 20. The image on the second side of the document is read.

  The image reading device 120 matches the reading accuracy of the scanner unit 70 with the reading accuracy of the CIS 20 during the reading process of the double-sided simultaneous reading method that reads the images on both sides of the document as monochrome image data, and sets the document conveying speed of the automatic document conveying device 72. It is determined based on the reading speed of CIS20. The images on the front and back surfaces of the document are read with the same reading accuracy, the quality of the image reproduced on the paper can be kept constant, and the reading process can be performed at a relatively high speed. Even when scanning images on both sides of a document as color image data, if it is not necessary to maintain a high quality of the image reproduced on the paper, the duplex scanning method should be performed at high speed. May be.

  FIGS. 4A to 4I are cross-sectional views showing the state of conveyance of a document during a reading process in the document reversal reading method in the image reading device 120. FIG. The image reading device 120 reverses and conveys the front and back surfaces of the document in the automatic document conveying device 72 during the reading process of the document reversal reading method, and does not perform the reading by the CIS 20, and only the scanner unit 70 reads the image from both the front and back surfaces. Read.

  When a plurality of documents 200 are placed on the document tray 1 of the automatic document feeder 72 and the image forming apparatus 100 is instructed to copy the images on both sides of the document as a color image on a sheet, the image forming apparatus 100 A document reverse reading start command is transmitted to the image reading device 120.

  Even when the image forming apparatus 120 is instructed to transmit the images on both sides of the document as color image data to an apparatus such as a PC or a facsimile apparatus, the image forming apparatus 100 starts the reverse reading of the document to the image reading apparatus 120. Send a command.

  When the image reading device 120 receives the document reverse reading start command, as shown in FIG. 4A, the rotation of the rollers 4, 5, 6 and the roller pairs 7A-7D, 10 of the automatic document feeder 72 is started. The pickup roller 4 is brought into contact with the uppermost surface of the document 200. As a result, as shown in FIG. 4B, the uppermost sheet 201 of the plurality of documents 200 placed on the document tray 1 passes between the feeding roller 5 and the separating roller 6 and is mainly conveyed. Guided into the road 3.

  The image reading device 120 starts reading the image on the first surface of the original 201 by the scanner unit 70 at the timing when the leading edge of the paper 201 reaches the position of the sub-original table 71A. As shown in FIG. 4C, the automatic document feeder 72 swings the switching claw 9 upward to open the direction from the position where the auxiliary document table 71A is disposed toward the paper discharge tray 2. The document 201 is conveyed from the branch position 3B toward the arrangement position of the conveyance roller pair 7D and the discharge roller pair 10.

  As shown in FIG. 4D, when the rear end of the document 201 passes through the branch position 3B, the automatic document feeder 72 swings the switching claw 9 downward and moves from the branch position 3B to the reverse conveyance path 8. The direction is released, and the conveyance roller pair 7D and the discharge roller pair 10 are reversed. As a result, as shown in FIG. 4E, the original 201 is guided into the reverse conveyance path 8 with its front and rear ends reversed.

  The original 201 passes through the reverse conveyance path 3A and is guided into the main conveyance path 3 with the front and back surfaces reversed from the merge position 3C. The image reading device 120 starts reading the image on the second surface of the original 201 by the scanner unit 70 at the timing when the leading edge of the paper 201 reaches the arrangement position of the sub-original table 71A.

  As shown in FIG. 4 (F), the automatic document feeder 72 swings the switching claw 9 upward before the leading edge of the document reaches the branch position 3B, and discharges paper from the position where the sub-document table 71A is disposed. The direction toward the tray 2 is open. Further, the automatic document feeder 72 rotates the pair of conveyance rollers 7D and the pair of paper discharge rollers 10 in the normal direction at the timing when the rear end of the document 201 passes the branch position 3B. Thus, the front end of the document 201 is conveyed from the branch position 3B toward the paper discharge tray 2.

  As shown in FIG. 4G, when the rear end of the document 201 passes through the branch position 3B, the automatic document feeder 72 swings the switching claw 9 downward and moves from the branch position 3B to the reverse conveyance path 8. The direction is released, and the conveyance roller pair 7D and the discharge roller pair 10 are reversed. As a result, as shown in FIG. 4H, the document 201 is guided into the reverse conveyance path 8 with the front and rear ends reversed again, and is guided into the main conveyance path 3 via the merge position 3C. The original 201 passes through the arrangement position of the sub-original table 71A with the front and back surfaces reversed again, but the image reading device 120 does not read the image by the scanner unit 70.

  The automatic document feeder 72 swings the switching claw 9 upward at the timing when the rear end of the document 201 passes through the branch position 3B, and opens the direction from the placement position of the auxiliary document table 71A toward the sheet discharge tray 2. is doing. In addition, the automatic document feeder 72 rotates the pair of conveyance rollers 7D and the pair of paper discharge rollers 10 in the normal direction at the timing when the rear end of the document 201 passes the branch position 3B. As a result, as shown in FIG. 4I, the document 201 is conveyed from the branch position 3B toward the paper discharge tray 2, and is discharged to the paper discharge tray 2 with the second surface facing upward. A plurality of double-sided originals stacked and stored on the original tray 1 are stacked and stored on the discharge tray 2 without changing the page order.

  As described above, at the time of document reversal reading, the document is passed twice through the position of the sub document table 71A, and the images on the first and second surfaces of the document are read by the scanner unit 70 at each passage.

  The image reading device 120 determines the document conveying speed of the automatic document conveying device 72 based on the reading speed at the time of the high-precision reading process by the scanner unit 70 at the time of document reversal reading that reads the images on both sides of the document as color image data. . The front and back images of the original are read with the same reading accuracy, and the quality of the image reproduced on the paper can be kept constant, and high-quality reading processing can be performed. Even when images on both sides of a document are read as monochrome image data, if it is necessary to maintain a high quality of the image reproduced on the paper, the reading process may be performed by the document reversal method. .

  FIG. 5 is a schematic front sectional view showing a use state of the image forming apparatus. As described with reference to FIG. 2, the CIS 20 is detachably mounted on the bottom surface of the document tray 1 together with the cooling fan 11. The conveyance guide 24 is detachably attached to the upstream end portion of the paper discharge tray 2 in the original paper discharge direction integrally with the shading correction plate 25, the spring 26, and the support base 27.

  Therefore, the CIS 20, the cooling fan 11, the conveyance guide 24, the shading correction plate 25, the spring 26, and the support base 27 can be easily attached to the image reading device 120 and can be removed from the image reading device 120 relatively easily.

  For this reason, when it is no longer necessary to read images from the front and back sides of the original, or when it is necessary to read images from the front and back sides of the original, It is possible to easily delete and add the duplex reading function.

  The CIS 20 may be integrally provided on the bottom surface of the document tray 1. By changing the document tray 1, it is possible to cope with a change in the function of the image reading apparatus 120.

  A space is provided below the document tray 1 and the paper discharge tray 2. Therefore, the CIS 20, the cooling fan 11, the conveyance guide 24, the shading correction plate 25, the spring 26, and the support base 27 can be easily attached to and detached from the downstream end of the document tray 1 without interfering with other components. It can be carried out.

  Further, since the shading correction plate 25, the spring 26, and the support base 27 are integrated with the transport guide 24, the attaching / detaching operation can be performed more easily. However, a part or all of the transport guide 24, the shading correction plate 25, the spring 26, and the support 27 may be individually attached and detached, and the CIS 20 and the cooling fan 11 are integrated with the transport guide 24. You can also

  It should be noted that the present invention can be similarly implemented even in an automatic document feeder 72 in which the reverse conveyance path 8 is not formed and the image reading process from both the front and back sides of the document is performed only by the double-sided simultaneous reading method. it can.

  The description of the above-described embodiment is an example in all respects and is not restrictive. The scope of the present invention is shown not by the above embodiments but by the claims. Furthermore, the scope of the present invention is intended to include all modifications within the meaning and scope equivalent to the scope of the claims.

1 is a schematic front sectional view of an image forming apparatus including an image reading apparatus according to the present invention. 1 is a schematic front sectional view of an image reading apparatus which is an example of an embodiment of the present invention. FIGS. 4A to 4F are cross-sectional views illustrating a document conveyance state in the reading process of the double-sided simultaneous reading method in the image reading apparatus 120. FIG. FIGS. 7A to 7I are cross-sectional views illustrating a document conveyance state during a reading process using the document reversal reading method in the image reading apparatus 120. FIG. It is a schematic front sectional view showing another use state of the image forming apparatus.

Explanation of symbols

1-document tray 2-discharge tray 3-main transport path 8-reverse transport path 20-CIS (second reading means)
70-scanner unit (first reading means)
72-automatic document feeder 100-image forming apparatus 120-image reading apparatus

Claims (7)

A document tray for storing documents before image reading processing;
A paper discharge tray disposed below the document tray with a space between the document tray and storing the document after image reading processing;
A main conveyance path including a U-shaped curved portion between the document tray and the document discharge tray, and passes downstream of the curved portion and below the end of the document tray on the main conveyance path side. A main transport path to
First reading means for reading an image of the first surface of the document being conveyed in the main conveyance path from the outside of the curved portion;
An image reading apparatus provided with a second reading unit configured to read an image on a second surface of the document being conveyed below an end of the document tray on the main conveyance path side;   Between the branch position formed between the arrangement position of the first reading means and the arrangement position of the second reading means in the main conveyance path to the merge position formed on the upstream side of the first reading means. The image reading apparatus according to claim 1, wherein a reversal conveyance path for conveying a document with the front and rear ends reversed is formed.   The image reading apparatus according to claim 1, wherein the second reading unit is integrally disposed on a bottom surface of the document tray.   A shading correction plate for correcting shading of the second reading unit at a position facing the second reading unit across the main transport path, and a discharge member for discharging the document to the discharge tray, The image reading apparatus according to claim 3, wherein the image reading apparatus is detachably provided integrally with a guide member that guides to a paper discharge tray.   The image reading apparatus according to claim 1, wherein the second reading unit is an equal magnification optical system sensor.   6. A document reading apparatus according to claim 3, wherein a cooling fan is provided on the bottom surface of the document tray to exhaust air on the second reading means side to a space between the document tray and the paper discharge tray. .   An image forming apparatus comprising: the image reading apparatus according to claim 1; and an image forming unit that forms an image on a recording medium based on image data read from a document by the image reading apparatus.

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