JP6119961B2 - Reading apparatus and image forming apparatus - Google Patents

Description

  The present invention relates to an image reading apparatus and an image forming apparatus.

  A copier, a copier, a facsimile machine, or a multifunction machine having two or more functions is a flat head scanner that moves an image sensor while fixing an original on a document table, or an automatic document that is fixed with an image sensor. The image reading apparatus includes an ADF scanner that is moved by a feeding device (hereinafter referred to as ADF). Some models have both functions of a flat head scanner and an ADF scanner.

  Some image reading apparatuses having both of these functions share one reading unit for both a flat head scanner and an ADF scanner. In other words, a single reading unit is provided between the original window dedicated to flow reading and the original platen for the flat head scanner adjacent to the original window so as to be able to move in a submerged manner. Yes. The underwater movement is an operation in which a traveling body (traveling body) on which an image sensor is mounted climbs over a glass support frame between a flow reading document window and a document table.

  By the way, the image reading apparatus is classified into a reduction optical system and an equal magnification optical system according to an imaging method. The reduction optical system reduces an image of a document with a reduction lens, and reads this with a reduction sensor configured by a CCD (Charge Coupled Device) or the like. In the 1 × optical system, a 1 × magnification sensor composed of a CCD, a CIS (Contact Image Sensor) or the like is arranged close to the document surface, and an image is directly read from the document surface by the 1 × magnification sensor.

  The reduction optical system has a deeper depth of focus than the equal-magnification optical system and is advantageous for floating a document. Therefore, the reduction optical system can cope with image reading of books and three-dimensional objects. A multifunction machine (MFP) or a high-end machine equipped with a digital scanner often has a reading device of this reduction optical system. However, the reduction optical system is disadvantageous for downsizing the apparatus because the optical path length is long. Further, since the reflected light from the document is folded back by a plurality of mirrors and guided to the image pickup device, there is a disadvantage that the reading unit is increased in size and weight, and power consumption is large for driving the reading unit.

  On the other hand, the 1 × optical system is advantageous for reducing the size and thickness of the device and saving energy because the optical path length is short. However, since the focal depth is as shallow as about 0.2 mm, a large image abnormality occurs when the focal length changes even a little. There is a drawback that occurs. For this reason, it is necessary to obtain the reading information of the original from the reading unit by moving the reading unit in the sub-scanning direction while keeping the distance (focal length) between the original surface and the reading unit constant.

  For example, Patent Document 1 (Japanese Patent Laid-Open No. 10-186535) and Patent Document 2 (Japanese Patent Laid-Open No. 2007-36426) disclose an image reading apparatus equipped with such a contact image sensor (CIS) of an equal magnification optical system. It is disclosed. FIG. 12A conceptually shows the traveling body (running body) described in Patent Document 1. FIG. In the figure, reference numeral 110 denotes an original platen made of transparent plate glass disposed on the upper part of the image reading apparatus.

  A guide rod 113 is horizontally disposed below the document table 110 in the sub-scanning direction, and a bearing 112a of the traveling body 112 is attached to the guide rod 113 so as to be movable in the longitudinal direction. The traveling body 112 is reciprocated by driving means (not shown) using a timing belt, a wire, or the like.

  A reading unit 114 is mounted on the traveling body 112. The reading unit 114 is attached to be swingable in the vertical direction around a fulcrum pin 112f disposed at one end of the traveling body 112 in the moving direction.

  The reading unit 114 is urged upward, that is, toward the document table 110 by a compression spring 108 disposed between the reading unit 114 and the traveling body 112. On the upper side of the reading unit 114, an interval regulating portion 112g that is slidably in contact with the lower surface of the document table 110 is disposed on the side opposite to the fulcrum pin 112f. The spacing regulating portions 112g are disposed at least in pairs in the longitudinal direction of the reading unit 114, that is, at both ends in the main scanning direction, and abut against the lower surface of the document table 110 to thereby contact the contact type image sensor (CIS) 115 of the reading unit 114. The distance C from the document table 110 is kept constant.

  The reading unit 114 is connected to a relay board on the apparatus main body side via a flexible flat cable (FFC) 120. The FFC 120 is elastic, and an end bent in a U shape is fixed to the lower surface of the traveling body 112 and is connected to the reading unit 114 by another short FFC 121 from the fixed end. And it is comprised so that the U-shaped bending part of FFC120 may move as the traveling body 112 moves.

  As shown in FIG. 12A, when the traveling body moves to the end position in the sub-scanning direction so as to extend the FFC the most (the position immediately below the flow-reading document window), the bent portion of the FFC 120 comes closest to the traveling body 112. If it does so, while the curvature radius of the bending part of FFC120 will become the minimum, the strong elastic repulsive force will act on the direction which pushes up traveling body 112.

  Therefore, the conventional traveling body 112 supports the reading unit 114 so as to be rotatable about the fulcrum pin 112f as described above, and even if the traveling body 112 is pushed up at the end of the FFC 120, the influence of the pushing force is not affected. By escaping with the fulcrum pin 112f, a tilt error does not occur in the reading unit 114.

  However, even if the tilting error of the reading unit 114 can be prevented, for example, if the dimensional accuracy in the height direction of the support portion 112h that supports the reading unit 114 varies, the reading unit 114 is spaced as shown in FIG. 12B. The optical axis of the CIS 115 of the reading unit 114 is tilted with the restricting portion 112g as a fulcrum. If it does so, the focal distance of CIS115 will also become longer than an original distance, and will cause an image abnormality.

  The cause of such a phenomenon is not limited to variations in dimensional accuracy of the support portion 112h. The dimensional accuracy of each part from the guide rod 113 to the fulcrum pin 112f is all affected. Such image abnormality due to variations in dimensional accuracy can be solved by increasing the dimensional accuracy and assembly accuracy of each component, but the cost of the apparatus becomes high.

  Therefore, an object of the present invention is to prevent the posture of the reading unit and the distance from the document table from being affected even if the dimensional accuracy and assembly accuracy of the parts of the traveling body that supports the reading unit vary. .

  In order to solve the above-described problems, the present invention provides a traveling body having a reading unit extending in the main scanning direction along a lower surface of a document table on which a document is placed, and connecting a flexible cable to a receiving port of the traveling body. The reading unit is arranged so as to be movable in a sub-scanning direction perpendicular to the main scanning direction, and the reading unit receives a light source that irradiates the original, and reflected light from the original by the light source and receives this as an electric signal. An image reading unit having a same-magnification optical system that converts the image into an optical system, and an interval regulating unit that is in contact with the lower surface of the document table at both end positions in the main scanning direction and regulates the interval between the reading unit and the document table. In the apparatus, the traveling body urges the reading unit toward the document table by an urging unit, and can move the reading unit up and down and has a tilting shaft extending in a longitudinal direction of the reading unit as a center. When And the interval restricting portion is constituted by at least a pair spaced apart in the sub-scanning direction, and an urging force by the urging means is applied between the pair of interval restricting portions. The image reading apparatus.

  According to the present invention, the reading unit is urged toward the document table by the urging means, and the reading unit can be moved up and down, and can be tilted about the tilting shaft extending in the longitudinal direction of the reading unit. In addition, since the interval restricting portion is composed of at least a pair spaced apart in the sub-scanning direction and the urging force by the urging means is applied between the pair of interval restricting portions, the dimensions of the parts of the traveling body that supports the reading unit Even if the accuracy and assembly accuracy vary, it is possible to prevent the posture of the reading unit and the distance from the document table from being affected. Therefore, since it is not necessary to increase the dimensional accuracy of the parts, the cost of the apparatus can be reduced.

1 is a schematic view of an image forming apparatus equipped with an image reading apparatus according to an embodiment of the present invention. 1 is a perspective view of a housing of an image reading apparatus according to an embodiment of the present invention. 1 is an exploded perspective view of a housing of an image reading apparatus according to an embodiment of the present invention. 1 is a schematic cross-sectional view of an image reading apparatus according to an embodiment of the present invention. 1 is a perspective view of an image reading apparatus according to an embodiment of the present invention. FIG. 5 is a cross-sectional view taken along line VV in FIG. 4. 1 is a perspective view of a traveling body of an image reading apparatus according to an embodiment of the present invention. It is a perspective view of the edge part of the traveling body of the image reading apparatus which concerns on embodiment of this invention. 1 is a perspective view of a traveling body in a state where a reading unit of an image reading apparatus according to an embodiment of the present invention is removed. It is the perspective view seen from another direction of the run with the reading unit of the image reading device concerning the embodiment of the present invention removed. FIG. 7 is a cross-sectional view taken along line IX-IX in FIG. 6 of the traveling body of the image reading apparatus according to the embodiment of the present invention. It is an expansion perspective view of the edge part (X part) of the traveling body of FIG. 1 is a schematic cross-sectional view of a traveling body of an image reading apparatus according to a first embodiment according to an embodiment of the present invention. It is a schematic sectional drawing of the traveling body of the image reading apparatus which concerns on 2nd Embodiment which concerns on embodiment of this invention. It is a schematic sectional drawing of the traveling body of the image reading apparatus which concerns on 3rd Embodiment of this invention. It is a schematic sectional drawing of the traveling body of the conventional image reading apparatus. It is a schematic sectional drawing of the traveling body which shows the state in which the reading unit inclines when the dimensional accuracy of components in the conventional image reading apparatus varies.

  Hereinafter, an image forming apparatus equipped with an image reading apparatus according to an embodiment of the present invention will be described with reference to the accompanying drawings. In the following description, parts / members in each drawing having the same function and shape are denoted by the same reference numerals, and once described, the same description is omitted as appropriate.

  The image reading apparatus according to the embodiment of the present invention may be applied to an image scanner. Examples of the image forming apparatus include a copying machine having an image scanner, a facsimile machine, and a multifunction machine having a copying machine and a facsimile function. Can be applied to. The image forming apparatus can also have a function of transmitting an image read by an image transmission / reception apparatus (not shown) to a terminal such as a user's personal computer through communication means such as a LAN.

(Image forming device)
As shown in FIG. 1, the image forming apparatus 100 includes an image forming unit 101, a paper supply device 40, and an image reading unit 104. The image reading unit 104 includes an image reading device 102 fixed on the image forming unit 101, and an ADF (Auto Document Feeder) 103 as a document conveying device supported by the image reading device 102.

  The paper supply device 40 has two paper feed cassettes 42 arranged in multiple stages in the paper bank 41, a feed roller 43 that feeds paper as a recording medium from the paper feed cassette 42, and separates and feeds the fed paper. A separation roller 45 supplied to the path 44 is included. In addition, the image forming apparatus 100 includes a plurality of transport rollers 46 that transport the paper to the paper feed path 37. The paper in the paper feed cassette 42 is fed to the paper feed path 37 in the image forming apparatus 100.

  The image forming unit 101 includes an optical writing device 2, a transfer unit 24 having four process units 3K, 3Y, 3M, and 3C for forming toner images of K, Y, M, and C colors, an intermediate transfer belt 25, and paper A transport unit 28, a timing roller pair 33, a fixing device 34, a paper discharge roller pair 35, a switchback device 36, a paper feed path 37, and the like are provided.

  Then, a light source such as a laser diode or LED (not shown) disposed in the optical writing device 2 is driven, and laser is directed toward the photosensitive members 4K, 4Y, 4M, and 4C of the process units 3K, 3Y, 3M, and 3C. Irradiate light L.

  By irradiation with the laser light L, an electrostatic latent image is formed on the surface of the drum-shaped photoconductors 4K, 4Y, 4M, and 4C, and the electrostatic latent image is developed into a toner image through a predetermined development process. Is done. Subscripts of K, Y, M, and C after the symbol indicate that the specifications are for black, yellow, magenta, and cyan.

  In the image forming apparatus 100 having the above-described configuration, the toner images formed on the surfaces of the photoconductors 4K, 4Y, 4M, and 4C are sequentially superimposed on the intermediate transfer belt 25 that moves endlessly in the clockwise direction in FIG. Is done.

  By this primary transfer, a four-color superimposed color toner image is formed on the intermediate transfer belt 25. The paper supplied from the paper supply device 40 is sent to the secondary transfer nip formed between the paper transport unit 28 and the intermediate transfer belt 25 by the timing roller pair 33 at a predetermined timing, and the intermediate transfer belt. The color toner image on the image 25 is secondarily transferred onto the paper at once.

  The sheet that has passed through the secondary transfer nip is separated from the intermediate transfer belt 25 and conveyed to the fixing device 34. The sheet conveyed to the fixing device 34 is fixed to the full color image by pressure or heating in the fixing device 34, then sent from the fixing device 34 to the paper discharge roller pair 35, and then discharged outside the apparatus. . The image forming unit 101 is not limited to the configuration shown in FIG. 1, and may be a configuration such as an inkjet recording method.

(Image reading device)
As shown in FIGS. 2A and 2B, the image reading device 102 disposed on the image forming unit 101 includes a scanner frame portion 102a as a housing that forms the side surface and the lower surface of the image reading device 102, and the scanner frame. A scanner cover portion 102b attached to the upper opening of the portion 102a.

  The scanner cover portion 102b of the image reading apparatus 102 constitutes the upper surface of the image reading apparatus 102, and includes an original table 110 made of a plate glass on which an original is placed, and a flow reading window 111 made of a belt-like plate glass through which the original passes when the ADF is used. .

  Inside the scanner frame portion 102a of the image reading apparatus 102, a traveling body 112 extending in the main scanning direction, and a guide rod 113 as a guide member for guiding the traveling body 112 in the sub scanning direction orthogonal to the main scanning direction. Is provided. Then, an original is placed on the original platen 110 of the scanner cover section 102b, and the original is read by moving the traveling body 112 in the sub-scanning direction (arrow direction) by the driving unit immediately below the original platen 110.

  The driving means for driving the traveling body 112 can be constituted by a wire (not shown) fixed to the traveling body 112, a plurality of driven pulleys and driving pulleys around which the wire is wound, a motor for rotating the driving pulley, and the like. Such driving means are well known and are not shown in the figure.

  As shown in FIGS. 2B and 3, a guide rod 113 positioned below the document table 110 is disposed in the horizontal direction (sub-scanning direction) in the vicinity of the center inside the scanner frame portion 102 a of the image reading apparatus 102. Yes. A traveling body 112 connected to the FFC 120 is movably attached to the guide rod 113. A glass support frame 109 is disposed between the document table 110 and the flow reading window 111.

  FIG. 4 is a view seen from above through the document table 110 of the image reading apparatus 102. The traveling body 112 is movable from the left-side flow reading position serving as the standby position to the right-side maximum scanning position.

  5 is a cross-sectional view taken along line VV in FIG. The left side is a flow reading position I which is a standby position of the traveling body 112, and the right side is a maximum scanning position II. FIG. 6 is a view of the traveling body 112 as viewed obliquely from above, and shows a state where the bearing 112a of the traveling body 112 is covered with the guide rod 113 from above. The bearing 112a has a gate shape whose lower side is open in its cross-sectional shape, and a guide rod 113 is slidably inserted inside the bearing 112a.

  As shown in FIG. 7, two FFCs 120 and 121 are connected to one end of the traveling body 112. The ends of the FFCs 120 and 121 are fixed to the traveling body 112 by brackets 112b and 112c of the traveling body 112. One FFC 120 is connected to the main body side relay board 105 of the image reading apparatus 102 as shown in FIG. 3, and image information obtained by the reading unit is transmitted to the main body side by the FFC 112. The other FFC 121 is a short cable that connects the traveling body 112 and the reading unit 114 that can move up and down, and the end of the FFC 121 is connected to the FFC 120.

  As shown in FIGS. 7, 8A, and 8B, support plates 112d that rise upward are formed at both ends of the traveling body 112. As shown in FIG. A narrow rectangular cutout hole 112e extending in the vertical direction is formed in the support plate 112d. In this rectangular cutout hole 112e, a short protrusion 114a as a tilting shaft that protrudes in the horizontal direction from both ends of the reading unit 114 can move up and down with an appropriate gap inside the cutout hole 112e. And it is inserted so that rotation around the horizontal axis line of the projection part 114a is possible. The reading unit 114 includes a base on which a contact image sensor (CIS) 115 of an equal-magnification optical system as reading means is incorporated, a light source using LEDs, a housing in which a substrate and a light source are incorporated, and the like. The CIS 115 includes a lens array in which a plurality of cylindrical lenses are arranged in the main scanning direction, and a light receiving element such as a CCD disposed at an end of the lens array. As shown in FIGS. It is disposed at a position relatively close to the position 114a. Then, the original is irradiated with the light source, the reflected light is received by a light receiving element such as a CCD, and this is converted into an electric signal.

  As shown in FIGS. 8A, 8B, and 9, a pair of coil springs 116 as first urging means are vertically arranged on the traveling body 112 near both ends, and a second attachment is provided near the center. One coil spring 117 as a biasing means is arranged vertically. As shown in FIG. 9, the pair of coil springs 116 is disposed so as to be positioned directly below the protrusion 114 a of the reading unit 114 when the traveling body 112 is viewed from the end direction. Further, one coil spring 117 near the center is arranged on the side opposite to the receiving port 122 of the FFC 120.

  When the reading unit 114 is mounted on the traveling body 112, the upper ends of the coil springs 116 and 117 come into contact with the lower surface of the reading unit 114 and urge the reading unit 114 upward, that is, toward the lower surface of the document table 110. It is configured as follows. In a state where the reading unit 114 is assembled to the traveling body 112, the protrusions 114 a at both ends of the reading unit 114 are applied to the upper edge of the notch hole 112 e of the support plate 112 d of the traveling body 112 by the urging force of the coil springs 116 and 117. Abut.

  As a result, the reading unit 114 can be moved up and down in the direction of arrow A in FIG. 9, and can be tilted in the direction of arrow B around the protrusion 114a. Note that a pair of shaft portions 125 are vertically formed on the upper surfaces of both end portions of the traveling body 112 and at positions adjacent to the inside of the support plate 112d. The pair of shaft portions 125 are inserted into a guide hole formed on the lower surface of the reading unit 114 with a gap therebetween to guide the vertical movement of the reading unit 114.

  As shown in FIG. 10, a pair of left and right spacing regulating portions 114b and 114c are formed on the outer surface and the inner side in the main scanning direction on the upper surface of both ends of the reading unit 114, respectively. That is, a total of four interval restricting portions 114b and 114c are formed only at one end portion of the reading unit 114.

  These distance regulating portions 114b and 114c may be at least a pair separated in the sub-scanning direction. Therefore, only one of the outer space regulating portion 114b or the inner space regulating portion 114c may be provided. Then, as will be described later with reference to FIGS. 11A to 11C, the urging force of the coil spring 116 acts between the pair of interval regulating portions 114b (114c). Desirably, the urging force of the coil spring 116 acts just at the center of the pair of interval regulating portions 114b (114c). Thereby, the posture of the reading unit 114 is stabilized.

  Each of the interval restricting portions 114b and 114c has a triangular shape in which the center is the highest and both sides thereof are inclined downwardly in a straight line toward the sub-scanning direction. The interval regulating portions 114b arranged on the outer side in the main scanning direction are relatively narrow, and the interval regulating portions 114c formed on the inside are relatively wide.

  The height of the central top portion of each of the space regulating portions 114b and 114c is made uniform. Then, the tops of the total eight space regulating portions 114b and 114c at both ends of the reading unit 114 are slidably brought into contact with the lower surface of the document table 110 with a predetermined pressure by the biasing force of the coil springs 116 and 117 described above. As a result, the interval between the reading unit 114 and the document table 110 is restricted to a fixed interval.

  If the urging forces of the coil springs 116 and 117 are too strong, the frictional force between the space regulating portions 114b and 114c and the lower surface of the document table 110 increases, and an excessive load is applied to the drive system of the traveling body 112. On the other hand, if the force of the coil springs 116 and 117 is too weak, a gap is generated between the space restricting portions 114b and 114c and the lower surface of the document table 110, and an image abnormality is likely to occur. In particular, when the traveling body 112 moves through the glass support frame from the flow-reading document window 111 toward the document table 110, the gap is easily generated between the lower surface of the document table 110.

  As will be described later with reference to FIGS. 11A to 11C, in the embodiment of the present invention, the pair of coil springs 116 are arranged in accordance with the position of the protrusion 114 a that is the rotation center of the reading unit 114. . For this reason, the force of the coil spring 116 effectively acts on the reading unit 114. Therefore, even if the force of the coil spring 116 is weakened to some extent, there is no possibility that a gap will be generated between the space restricting portions 114 b and 114 c of the reading unit 114 and the lower surface of the document table 110. Thereby, driving force reduction and image abnormality prevention can be aimed at. Further, the tilt error of the reading unit 114 is effectively suppressed by the coil spring 117 as the second urging means. Therefore, the focal length of the CIS 115 can be kept constant.

FIG. 11A conceptually shows the first embodiment of the present invention.
Here, if the U-shaped bent portion of the FFC 120 connected to the traveling body 112 has a large radius of curvature, the length of the FFC 120 becomes longer and the cost increases, and the sub-scanning direction also increases in size. On the other hand, when the U-shaped bent portion has a small radius of curvature, the force of elastic repulsion in the direction in which the bending is released becomes stronger. In the conventional reading apparatus, the elastic repulsive force may cause the reading unit 114 to tilt and cause the focal length to be out of order.

  Therefore, in the embodiment of the present invention, the central portion of the reading unit 114 is urged toward the lower surface of the document table 110 by the first coil spring 116 as the first urging means, and the side opposite to the receiving port 122 is The second coil spring 117 as a biasing means is biased toward the lower surface of the document table 110. With this configuration, the elastic repulsive force of the FFC 120 acting on the traveling body 112 is released by the protrusion 114a that is the rotation fulcrum of the reading unit 114, and the tilt of the reading unit 114 is further tilted by the first coil spring 116 and the second coil spring 117. Can be suppressed. It is desirable that the urging force of the first coil spring 116 is applied in a direction that intersects with an extension line of the protrusion 114 a that is a tilting axis of the reading unit 114.

  Therefore, according to the present invention, it is possible to shorten the FFC 120 and reduce the size of the apparatus by changing the U-shaped bent portion with a small radius of curvature without changing the focal length. The position of the second coil spring 117 in the main scanning direction only needs to be between the first coil springs 116 at both ends, and does not have to be exactly the center of the reading unit 114 in the main scanning direction.

  FIG. 11B conceptually shows the second embodiment of the present invention. In the second embodiment, a third coil spring 118 as a third urging means is added to the receiving port 122 side. The third coil spring 118 can be disposed at a position symmetrical to the second coil spring 117 on the opposite side, with the first coil spring 116 at the center as a boundary.

  When the traveling body 112 moves to the right in FIG. 11B and the radius of curvature of the U-shaped bent portion of the FFC 120 increases, the force acting on the traveling body 112 from the FFC 120 is the direction in which the bending of the U-shaped bent portion is released (document A force may be generated not only in the direction toward the table 110) but also in the reverse direction (downward). Therefore, the third coil spring 118 is provided as described above to prevent the reading unit 114 from tilting due to the disturbance force from the FFC 120 and to stabilize the focal length.

  FIG. 11C conceptually shows the third embodiment of the present invention. In the third embodiment, only one fourth coil spring 119 as the fourth urging means is arranged in the short direction of the traveling body 112. Compared with FIG. 11A and FIG. 11B, the number of coil springs is reduced, and stabilization of the focal length can be achieved at low cost. The number of the fourth coil springs 119 disposed in the longitudinal direction of the traveling body 112 is arbitrary. For example, a pair of coil springs 119 can be provided at both ends of the traveling body 112, or another coil spring 119 can be added near the center of the traveling body 112 in the main scanning direction in addition to the pair of coil springs 119. .

  The coil spring 119 is arranged to be decentered by a predetermined distance X in the horizontal direction (sub-scanning direction) on the side opposite to the receiving port 122 side from the protrusion 114a that is the rotation center of the reading unit 114. The eccentric distance X is preferably set so that the rotational moment of the reading unit 114 around the protrusion 114 a is balanced with the rotational moment due to the elastic repulsive force of the FFC 120 via the FFC 121.

  In other words, the elastic repulsive force of the FFC 120 is usually in a direction of urging the traveling body 112 upward on the receiving port 122 side, that is, on the document table 110 side. The upward biasing force is biased by at least one biasing means (fourth coil spring 119) so as to balance the rotational moment acting on the reading unit 114 via the FFC 121 with the right and left in the short direction of the reading unit 114. As a result, the reading unit 114 can be stably urged to the document table 110. It is desirable that the coil spring 119 is disposed at an inner position of the left and right spacing regulating portions 114b and 114c. Further, it is desirable to arrange the coil spring 119 on the extension line of the CIS 115.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the technical idea described in the claims. For example, in the above-described embodiment, the interval restricting portion is formed as a triangular protrusion having an obtuse tip, but the interval restricting portion can be configured by a flat surface, a roller, or the like. Further, the urging means is not limited to the coil spring, and an urging means using any elastic member or magnetic force can be used. Moreover, although FFC was illustrated as a flexible cable, flexible arbitrary cables other than FFC can be used.

2: Optical writing devices 3K, 3Y, 3M, 3C: Process units 4K, 4Y, 4M, 4C: Photoconductor 24: Transfer unit 25: Intermediate transfer belt 28: Paper transport unit 33: Timing roller pair 34: Fixing device 35 : Paper discharge roller pair 40: Paper supply device 45: Separation roller 46: Conveyance roller 100: Image forming device 101: Image forming unit 102: Image reading device 102 a: Scanner frame unit 102 b: Scanner cover unit 104: Image reading unit 110: Document platen 111: Document window 112: Traveling body 112d: Support plate 112e: Notch hole 113: Guide rod 114: Reading unit 114a: Projection part 114b, 114c :: Spacing restriction part 116: Coil spring (first biasing means)
117: Coil spring (second urging means)
118: Coil spring (third biasing means)
119 coil spring 120, 121: FFC
122: Entrance

Japanese Patent Laid-Open No. 10-186535 JP 2007-36426 A

Claims (6)

A sub-scan that is perpendicular to the main scanning direction in a state in which a traveling body having a reading unit extending in the main scanning direction along the lower surface of the document table on which the original is placed has a flexible cable connected to a receiving port of the traveling body. The reading unit is movably arranged in a direction, and the reading unit includes a light source that irradiates the document, and a reading unit of an equal-magnification optical system that receives light reflected from the document by the light source and converts the light into an electric signal. An image reading apparatus having an interval restricting portion that restricts an interval between the reading unit and the document table in contact with the lower surface of the document table at both end positions in the main scanning direction.
The traveling body urges the reading unit toward the document table by urging means, and can move the reading unit up and down and can tilt about a tilting shaft extending in the longitudinal direction of the reading unit. To support
The interval restricting portion is composed of at least a pair spaced in the sub-scanning direction with the tilting shaft in between, and an elastic repulsive force is applied by the flexible cable toward one of the pair of interval restricting portions in the sub-scanning direction. And an urging force by the urging means is applied toward the other side in the sub-scanning direction . The urging unit includes a first urging unit that applies a urging force in a direction intersecting the tilting axis of the reading unit, and an opposite side of the receiving port of the flexible cable across the tilting axis . The image reading apparatus according to claim 1, further comprising a second urging unit that applies an urging force toward the other in the sub-scanning direction . In addition to the first urging means and the second urging means, the urging means applies a urging force toward one interval regulating portion in the sub-scanning direction on the receiving side of the flexible cable. The image reading apparatus according to claim 2, further comprising an urging unit. The biasing means is a fourth biasing means that is disposed only on the side opposite to the receiving port from the tilting shaft of the reading unit and applies a biasing force toward the other interval regulating portion in the sub-scanning direction. The image reading apparatus according to claim 1, wherein:   The reading unit of the equal-magnification optical system of the reading unit includes a lens array composed of a plurality of cylindrical lenses arranged in the main scanning direction, and a light receiving element disposed at an end of the lens array. The image reading apparatus according to claim 1, wherein the image reading apparatus is an image reading apparatus.   An image forming apparatus comprising the image reading apparatus according to claim 1.