JP2010062712A - Image reading apparatus and image forming apparatus - Google Patents

Abstract

An object of the present invention is to simplify document jam processing and maintenance of a reading means, and to prevent a reduction in strength of the apparatus.
A document tray 1 in which a CIS 20 is detachably mounted on a bottom surface of an end portion on a main transport path 3 side is used as a fulcrum by an end portion on the main transport path 3 side by shaft bodies 211 and 212 and concave portions 221 and 222. The automatic document feeder 72 was rotatably supported. By rotating the document tray 1 upward, the bottom surface of the document tray 1 on which the CIS 20 is mounted is exposed to the outside, and the CIS 20 itself and the position of the CIS 20 in the main transport path 3 can be accessed from the outside. Become. There is no need to form an opening / closing portion on the bottom surface of the automatic document feeder 72.
[Selection] Figure 2

Description

  The present invention relates to an image reading apparatus that reads an image 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 an image reading device that reads images on both sides of a document, both sides of the document are read by the two reading means while the document is transported in one direction in the document transport path. There is an apparatus (for example, refer to Patent Document 1).

  A conveyance path including a U-shaped curved portion is formed between the document tray and the paper discharge tray, and a first reading unit facing the first surface of the document being conveyed is disposed outside the curved portion and curved. A second reading unit is disposed opposite to the second surface of the document being conveyed on the downstream side. The conveyance path and the second reading unit are provided in an automatic document conveyance device including a document tray and a paper discharge tray. The automatic document feeder is rotatable on the upper surface of the first reading means with the back side as a hinge.

In consideration of convenience during jamming of the document in the vicinity of the position of the second reading unit in the transport path and maintenance of the second reading unit, the sheet is transported at the bottom surface of the automatic document feeder and the position of the second reading unit. The conveyance guide constituting the path is freely opened and closed.
JP 2006-74608 A

  However, in the conventional image reading device described in Patent Document 1, the bottom surface of the automatic document feeder and the bottom of the automatic document feeder are maintained during jamming of the document in the vicinity of the position of the second reading unit in the conveyance path and during the maintenance of the second reading unit. The conveyance guide must be opened and closed, which complicates the work. In addition, since it is necessary to open and close the bottom surface and the conveyance guide of the automatic document feeder, the strength of the automatic document feeder is reduced.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a document that can simplify the jam processing of the document and the maintenance of the reading unit by detachably mounting the reading unit on the bottom surface of the document tray, and can prevent a reduction in the strength of the apparatus. An object of the present invention is to provide a reading device and an image forming apparatus.

  The image reading apparatus of the present invention includes a document tray, a paper discharge tray, a conveyance path, a reading unit, and a support member. The document tray stores a document before image reading processing at the upper part of the apparatus main body. 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 conveyance path is formed to include a U-shaped curved portion between the document tray and the document discharge tray inside the apparatus main body, and the end of the document tray on the conveyance path side downstream from the curved portion. Go down. The reading unit is detachably mounted on the bottom surface of the end of the document tray on the conveyance path side, and reads an image of the document being conveyed. The support member rotatably supports the document tray on the apparatus body with the end on the conveyance path side as a fulcrum.

  In this configuration, a document tray in which a reading unit is detachably mounted on the bottom surface of the end portion on the conveyance path side is rotatably supported by the apparatus main body with the end portion on the conveyance path side serving as a fulcrum. Therefore, by rotating the document tray, the bottom surface on which the reading unit is mounted is exposed to the outside, and the reading unit itself and the arrangement position of the reading unit in the conveyance path can be accessed from the outside.

  In this configuration, it is preferable that the document tray is detachably supported by the support member with respect to the apparatus main body. The document tray replacement operation is facilitated, and it is possible to cope with a function change according to the presence or absence of the reading unit.

  Further, it is preferable that a conveyance guide is provided which forms a part of the conveyance path upstream from the paper discharge tray and is detachably mounted integrally with the reading unit on the bottom surface of the conveyance path side end.

  Further, the back side of the document tray is provided with an engaging portion that engages the back side end of the transport guide from the front side to the back side of the document tray, and the front side of the document tray is connected to the transport guide from the front side to the back side. It is preferable to provide an engaging tool that is engaged toward the front. The conveyance guide can be easily attached to and detached from the document tray from the front side.

  According to the present invention, by attaching the reading unit to the bottom surface of the document tray in a detachable manner, it is possible to simplify the document jam processing and the maintenance of the reading unit, and it is possible to prevent a reduction in the strength of the apparatus.

  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.

  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 corresponds to the apparatus main body of the present invention, and 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. The main conveyance path 3 is a conveyance path of the present invention.

  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 a reading unit 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.

  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 conveyance 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 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 detachably attached to an end portion of the paper 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.

  During simultaneous reading on both sides, the image reading device 120 reads an image on the first surface of the document by the scanner unit 70 while the document is being transported from the document tray 1 to the paper discharge tray 2 via the main transport path 3. To read the image on the second side of the document.

  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.

  At the time of reverse reading of the original, the image reading device 120 reverses the front and rear ends of the original on which the image on the first surface has been read by the scanner unit 70 by the reverse rotation of the conveying roller pair 7D and the discharge roller pair 10 to the reverse conveying path 8. Lead to. As a result, one original is passed twice through the placement position of the sub-original table 71A with the front and back sides reversed, and the images on the first and second sides of the original 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. 3 is a plan view of the document tray. A first shaft body 211 is formed on the rear side of the document tray 1 on the main conveyance path 3 side so as to extend in the back direction, and a second recess 222 is formed on the front side. A first recess 221 is formed on the back side of the upper part of the automatic document feeder 72, and a second shaft body 212 is detachably attached to the front side.

  The shaft 211 is engaged with the recess 221 from the front side toward the back side. The shaft body 211 is rotatable around the shaft while being engaged with the recess 211 that is a hole having a circular cross section. The shaft body 212 engages with the recess 222 from the front side toward the back side. The recess 222, which is a hole having a circular cross section, is rotatable about the shaft of the shaft body 212 in a state where the shaft body 212 is engaged. The shaft bodies 211 and 212 and the recesses 221 and 222 constitute a support member of the present invention.

  Therefore, the document tray 1 is rotatably supported on the upper portion of the automatic document feeder 1 with the end on the main transport path 3 side as a fulcrum.

  FIG. 4 is a front view of the image reading apparatus in a state where the document tray is rotated. In the automatic document feeder 72 of the image reading device 120, when the document tray 1 is rotated upward with the end on the main conveyance path 3 side as a fulcrum, the bottom surface of the document tray 1 is exposed to the outside, and the main tray 1 The CIS 20 mounted on the bottom surface of the end on the conveyance path 3 side can be easily accessed.

  In addition, the upper conveyance guide 29 constituting the main conveyance path 3 at the position where the CIS 20 is arranged also rotates upward together with the document tray 1 and is separated from the lower conveyance guide 24. For this reason, it is possible to easily perform the jam processing of the document stopped at the position where the CIS 20 is arranged.

  By simply rotating the document tray 1, it is possible to perform jam processing at the position where the CIS 20 is disposed and maintenance of the CIS 20, thereby improving workability. Further, considering the workability at the time of jam processing at the position where the CIS 20 is arranged or during maintenance of the CIS 20, it is not necessary to form an opening / closing portion on the bottom surface side of the automatic document feeder 72, and the strength of the automatic document feeder 72 is increased. Can be ensured and contribute to miniaturization.

  FIG. 5 is a perspective view seen from the bottom side of the document tray. Fixing plates 231 and 232 are attached to the rear side and the front side at the end of the document tray 1 on the main transport path 3 side, respectively. Two fixing holes 241 are formed in the fixing plate 231, and two insertion holes 242 and one through hole 243 are formed in the fixing plate 232.

  Two locking pieces 251 are formed on the back surface of the conveyance guide 29 to which the CIS 20 is attached, and two protrusions 252 and one screw hole 253 are formed on the front surface. The locking piece 251 extends to the back side, and engages with the engagement hole 241 from the front side toward the back side. The protrusion 252 extends to the front side, and is fitted into the fitting hole 242 from the back side toward the front side.

  While the locking piece 251 is engaged with the engagement hole 241, the screw hole 253 is opposed to the through hole 243 in a state where the protrusion 252 is inserted into the insertion hole 242. The conveyance guide 29 is fixed to the document tray 1 by screwing a fixing screw 254 that penetrates the through hole 243 from the front side toward the back side into the screw hole 253.

  Accordingly, the upper conveyance guide 29 together with the CIS 20 can be attached to and detached from the bottom surface of the document tray 1 from the front side by attaching and detaching the fixing screw 254, and maintenance including replacement work of the CIS 20 can be easily performed.

  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 lower conveyance guide 24 is detachably attached to the upstream end of the sheet discharge tray 2 in the document 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 document, or when it is necessary to read images from the front and back sides of the original document, The reading function can be easily deleted and added.

  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. 3 is a plan view of a document tray. FIG. FIG. 3 is a front view of the image reading apparatus in a state where a document tray is rotated. FIG. 6 is a perspective view of the document tray viewed from the bottom side.

Explanation of symbols

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

Claims (7)

A document tray for storing documents before image reading processing at the top of the apparatus body;
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 conveyance path formed with a U-shaped curved portion between the document tray and the document discharge tray in the apparatus main body, and conveyed on the document tray downstream of the curved portion. A transport path that passes under the end of the roadside,
A reading unit that is detachably mounted on the bottom surface of the end of the document tray on the conveyance path side and reads an image of the document being conveyed;
An image reading apparatus comprising: a support member that rotatably supports the document tray on the apparatus main body with an end on the conveyance path side as a fulcrum.   The image reading apparatus according to claim 1, wherein the support member detachably supports the document tray with respect to the apparatus main body. The support member is disposed on the first and second end sides in the direction orthogonal to the document conveyance direction from the document tray to the conveyance path, with the axial direction parallel to the orthogonal direction. The first and second shaft bodies, and the first and second recesses into which the first and second shaft bodies are fitted in the orthogonal directions, respectively.
The image reading apparatus according to claim 1, wherein the first shaft body and the second recess are formed in the document tray, and the second shaft body and the first recess are formed in the apparatus main body. .   A transport guide that forms a part of the transport path upstream from the paper discharge tray, and further includes a transport guide that is detachably attached to the bottom surface of the end on the transport path side integrally with the reading unit; The image reading apparatus according to claim 1, further comprising: The document tray is provided with an engagement portion on the back side where the back side end of the conveyance guide engages from the front side to the back side of the document tray,
The image reading apparatus according to claim 4, further comprising an engagement tool that engages the front side of the document tray with the conveyance guide from the front side to the back side.   The image reading apparatus according to claim 1, wherein the reading unit is an equal magnification optical system sensor.   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.

Images