JP4898714B2 - Image reading apparatus and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image reader and image forming apparatus capable of preventing a supporting member, that supports slit glass, from being deformed by heat emitted by a light source. <P>SOLUTION: There are provided a screw 142 for fixing one end portion of a frame 132 in a longer direction on a main body 21 so as not to move the one end portion in the longer direction and a shorter direction of the frame 132; a shoulder screw 141 and a screw hole 132a for fixing another end portion of the frame 132 in the longer direction on the main body 21 so as to move the other end portion in the longer direction of the frame 132. A width of the screw hole 132a in the shorter direction of the frame 132 is formed approximately equal to an outer diameter of the shoulder screw 141, and a width of the screw hole 132a in the longer direction of the frame 132 is formed larger than the outer diameter of the shoulder screw 141. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to an image reading apparatus and an image forming apparatus. For example, the present invention relates to an image reading apparatus such as a scanner apparatus, and an image forming apparatus such as a copying machine and a facsimile apparatus equipped with the image reading apparatus.

  Conventionally, as this type of image reading apparatus and image forming apparatus, a slit glass that comes into contact with a document, a light source that illuminates the document, and an image sensor that receives reflected light from the document are received by the image sensor. A device that converts light into an electrical signal is known (for example, see Patent Document 1).

  FIG. 15 is a perspective view of a slit glass of a conventional image reading apparatus. As shown in FIG. 15, in the conventional image reading apparatus, the slit glass 221 is supported by a metal support member 223, and both longitudinal ends of the support member 223 are fixed to the housing 226 by screws 224 and 225. It has become. In addition, the light source 202 illuminates the document conveyed so as to be in contact with the upper surface of the slit glass 221 at a fixed position.

Further, in recent image reading apparatuses, it is required to increase the light quantity of the light source 202 in order to satisfy the demands for higher reading speed and higher image quality.
JP 2007-67881 A

  However, in such a conventional image reading apparatus and image forming apparatus, when the light source 202 is turned off or at a normal temperature immediately after the light source 202 is turned on, as shown in FIG. Although the straight line state is maintained, when the slit glass 221 and the support member 223 become high temperature due to heat generated by the light source 202, the support member 223 is convex upward due to expansion as shown in FIG. Since the slit glass 221 is lifted by the deformation, the reading position of the original is shifted or the path length of the reading optical system is extended. As shown in FIG. 16C, the support member 223 is protruded downward due to expansion. There is a problem that the support member 223 comes into contact with the light source 202 or a carriage (not shown) that supports the light source 202 by deforming into the shape.

  The present invention has been made to solve such a problem, and provides an image reading apparatus and an image forming apparatus capable of preventing a support member supporting a slit glass from being deformed by heat generated by a light source. It is.

  An image reading apparatus according to the present invention includes a slit glass that contacts an original, a support member that supports the slit glass, a light source that illuminates the original through the slit glass, and a reading unit that reads reflected light from the original. In the image reading apparatus provided, a first fixing means for fixing one end portion in the longitudinal direction of the support member to the housing so that the one end portion does not move in the longitudinal direction and the short direction of the support member; and And a second fixing means for fixing the other end in the longitudinal direction to the housing so that the other end can move in the longitudinal direction of the support member.

  With this configuration, one end portion in the longitudinal direction of the support member that supports the slit glass is fixed to the housing by the first fixing means so that the one end portion does not move in the longitudinal direction and the short direction of the support member. The other end in the longitudinal direction is fixed to the housing by the second fixing means so that the other end can move in the longitudinal direction of the support member, so that the temperature of the support member rises due to the heat generated by the light source, and the thermal expansion occurs. At this time, since the other end portion in the longitudinal direction of the support member can move in the longitudinal direction, the support member is not curved and has a convex shape. Therefore, it is possible to prevent the support member that supports the slit glass from being deformed by the heat generated by the light source. In addition, since the support member is not curved and has a convex shape, it is possible to prevent the support member from coming into contact with other peripheral members and the position of the slit glass from shifting.

  In the image reading apparatus according to the present invention, the second fixing unit is provided in a stepped screw that is screwed into the housing and the support member, and the width of the support member in the short direction is the stepped. The stepped screw insertion hole is formed to be substantially equal to the outer diameter of the screw and the width of the support member in the longitudinal direction is larger than the outer diameter of the stepped screw. .

  With this configuration, since the width of the insertion hole of the stepped screw in the longitudinal direction of the support member is formed larger than the outer diameter of the stepped screw, the support member can be supported even if it is expanded in the longitudinal direction by the heat of the light source. The other end in the longitudinal direction of the member can move, and the width of the insertion hole of the stepped screw in the short direction of the support member is formed to be substantially equal to the outer diameter of the stepped screw. Since the position in the direction can be kept constant, the position of the support member can be kept constant, and the support member can be prevented from being deformed by the heat generated by the light source.

  The image reading apparatus according to the present invention is characterized in that the support member is made of metal.

  With this configuration, since the support member is made of metal, expansion and plastic deformation due to heat can be reduced as compared with the case where the support member is made of resin or the like.

  Further, the image reading apparatus according to the present invention is characterized in that the support member is divided in one side or both ends in the longitudinal direction of the support member in the lateral direction of the support member.

  With this configuration, it is possible to prevent the support member from being deformed due to a temperature difference between the side close to the light source and the side far from the light source among the divided support members.

  Further, the image reading apparatus according to the present invention is characterized in that the second fixing means is arranged on the side of the divided support member close to the light source.

  With this configuration, expansion of the support member due to heat from the light source is on the side close to the light source among the divided support members, but the other longitudinal end of the support member on the side close to the light source is moved by the second fixing means. Therefore, it is possible to prevent the support member from being deformed.

  An image forming apparatus according to the present invention includes the image reading apparatus described above.

  With this configuration, the support member that supports the slit glass can be prevented from being deformed by the heat generated by the light source.

  ADVANTAGE OF THE INVENTION According to this invention, the image reading apparatus and image forming apparatus which can prevent that the supporting member which supports slit glass deform | transforms with the heat which a light source emits can be provided.

  Embodiments of the present invention will be described below with reference to the drawings.

(First embodiment)
FIG. 1 is a schematic configuration diagram of an image reading apparatus and an image forming apparatus according to a first embodiment of the present invention. FIG. 2 is a schematic configuration diagram of the ADF of the image reading apparatus and the image forming apparatus according to the first embodiment of the present invention. FIG. 3 is a block diagram of the drive system of the image reading apparatus and the image forming apparatus according to the first embodiment of the present invention. Note that the image forming apparatus can be applied to an image forming apparatus such as a copier equipped with an image reading apparatus such as a scanner apparatus, a facsimile apparatus, a multi-functional apparatus having a copying function and a facsimile function, and the like. In this embodiment, a copying machine will be described as an example.

  First, the configuration will be described.

  As shown in FIGS. 1 and 2, a contact glass 22 is provided on the upper surface of a main body 21 that is a casing of the copying machine 20, and the upper surface of the main body 21 adjacent to the contact glass 22 is larger than the contact glass 22. A small area slit glass 131 is provided. The slit glass 131 may be referred to as a sheet-through DF contact glass or simply referred to as a contact glass.

  Further, an ADF 23 as an automatic paper transport device is provided on the upper portion of the main body 21. The ADF 23 can be opened and closed so as to open and close the contact glass 22 via a hinge mechanism (not shown). Here, the contact glass 22 is for reading a document placed on the contact glass 22 and stopped. On the other hand, the slit glass 131 is for reading a document conveyed by the ADF 23.

  The ADF 23 separates and feeds originals one by one from the original table 24 on which the original bundle P made up of stacked originals is placed with the original surface facing upward, and the original bundle P placed on the original table 24. The sheet feeding unit 25 to be aligned, the fed document is abutted and aligned to correct the skew, the registration unit 26 to draw out and transport the aligned document, and the conveyed document to be reversed to A turn unit 27 that conveys the surface toward the slit glass 131, a first reading conveyance unit 28 that reads a surface image of a document by a reading unit (not shown) provided below the contact glass 22; A second reading / conveying unit 29 for reading the back side image of the document after completion, a paper discharge unit 30 for discharging the document whose front and back sides have been read out of the ADF 23, and a stack for holding the document after the reading is completed. Tsu and a click portion 31.

  Further, as shown in FIG. 3, the ADF 23 is a series of operations of the ADF 23 and a pickup motor 101 that performs various driving operations including a conveyance operation, a paper feed motor 102, a reading motor 103, a paper discharge motor 104, and a bottom plate raising motor 105. And a controller 100 for controlling the above.

  Document length detection sensors 32 and 33 for detecting the length of the document are provided on the table surface of the document table 24. The document length detection sensors 32 and 33 may be a reflection type sensor or a single document. It is composed of an actuator type sensor that can be detected, etc., and detects the length of the document in the conveyance direction and outputs a detection signal to the controller 100. Therefore, the document length sensors 32 and 33 are arranged on the table surface of the document table 24 so that at least whether the document size is vertical or horizontal can be determined.

  A movable table 34 is provided at the front end of the document table 24 (downstream in the document transport direction). The movable table 34 is moved up and down by a bottom plate raising motor 105 as indicated by arrows ab.

  The document table 24 is provided with a side guide (not shown), and the side guide positions the document bundle P in the width direction (direction perpendicular to the document transport direction).

  A set filler 35 and a document set sensor 36 are provided in the vicinity of the movable table 34. The set filler 35 moves from the position indicated by the broken line to the position indicated by the solid line when the document bundle P is placed on the document table 24, and the document set sensor 36 changes from the state in which the set filler 35 is detected to the undetected state. When it changes, a signal is output to the controller 100. When this signal is output from the controller 100 to the main body control unit 111 of the main body 21 via the I / F 107, the main body 21 shifts to a standby state for reading a document.

  Further, when the controller 100 determines that the document bundle P is placed on the document table 24 based on the detection signal from the document set sensor 36, the controller 100 raises the bottom plate raising motor 105 to raise the top surface of the document bundle P. Is brought into contact with the pickup roller 37.

  The pickup roller 37 is transmitted with a driving force from the pickup motor 101 via a cam mechanism (not shown), and is in contact with the upper surface of the original bundle P as indicated by arrows cd by the pickup motor 101 and the cam mechanism. It moves up and down between the positions to be saved.

  A table raising sensor 38 is provided above the movable table 34. When the movable table 34 rises in the direction of the arrow c and the pickup roller 37 rises, the table raising sensor 38 detects the upper limit that can be raised by detecting the position of the pickup roller 37.

  When the print key of the operation unit 108 provided on the main body 21 side is pressed and a document feed signal is transmitted from the main body control unit 111 to the controller 100 via the I / F 107, the pickup roller 37 feeds the paper. The motor 102 is rotationally driven by normal rotation, and feeds several (ideally one) originals on the original table 24.

  The fed document is conveyed to a separation sheet feeding unit including a sheet feeding belt 39 and a reverse roller 40 provided on the downstream side of the pickup roller 37.

  The paper feed belt 39 is driven to rotate in the paper feed direction (clockwise) by the forward rotation of the paper feed motor 102. The reverse roller 40 is driven to rotate in the direction opposite to the paper feed direction (clockwise) when the paper feed motor 102 is driven forward by the action of a built-in torque limiter (not shown). For this reason, even when the pickup roller 37 picks up several originals, the uppermost original and the original below are separated, and only the uppermost original is fed.

  Specifically, the reverse roller 40 is in contact with the paper feeding belt 39 at a preset pressure, and is in direct contact with the paper feeding belt 39 or in a state of being in contact with one original. When the paper feed belt 39 rotates counterclockwise and the document enters between the paper feed belt 39 and the reverse roller 40 by two or more sheets, the follower force is larger than the torque limiter set torque. It becomes lower and rotates in the clockwise direction, which is the original driving direction, and pushes back an excess document to prevent double feeding. The original separated by the action of the paper feed belt 39 and the reverse roller 40 is conveyed by the paper feed belt 39.

  An abutting roller 41 is provided on the downstream side of the paper feeding belt 39. The abutting roller 41 includes a driving roller 41a and a driven roller 41b, and is driven to rotate by the paper feed motor 102.

  The abutting roller 41 corrects the skew of the original separated by the action of the paper feed belt 39 and the reverse roller 40, and conveys the skew-corrected original further downstream. .

  That is, since the paper feed motor 102 is stopped when the document is fed, the abutting roller 41 is also stopped, and the leading end of the separated document is provided on the upstream side of the abutting roller 41. After being detected by the abutting sensor 42, it is abutted against the abutting roller 41.

  When the abutting sensor 42 detects the leading edge of the document and outputs a signal to the controller 100, the controller 100 drives the paper feeding motor 102 by a predetermined distance from the detection of the abutting sensor 42 to feed the paper feeding belt. No. 39 is moved around so that the document is pressed against the abutting roller 41 with a predetermined amount of bending.

  In addition, the controller 100 rotates the pickup motor 101 before the paper feed motor 102 stops, so that the pickup roller 37 is retracted from the upper surface of the document bundle P. At this time, the document is fed only by the conveying force of the paper feed belt 39, so that the leading edge of the document enters the nip between the driving roller 41a of the abutting roller 41 and the driven roller 41b, and the skew of the document is corrected.

  The controller 100 is configured to drive the paper feed motor 102 in the reverse direction after correcting the skew. At this time, the abutting roller 41 is rotationally driven by the paper feed motor 102, and the separated document is conveyed to the intermediate roller 43. The intermediate roller 43 includes a driving roller 43 a and a driven roller 43 b and is driven by the paper feed motor 102.

  When the paper feed motor 102 is driven in reverse, the driving force of the paper feed motor 102 is transmitted to the butting roller 41 and the intermediate roller 43 but not to the pickup roller 37 and the paper feed belt 39. It has become.

  A document width sensor 44 is provided on the downstream side of the abutting roller 41. A plurality of document width sensors 44 are provided from the front side to the back side in FIG. 2, and detects a conveyed document and outputs a signal to the controller 100. The controller 100 detects the size of the document in the width direction (direction perpendicular to the transport direction) based on a signal from the document width sensor 44.

  The length of the document in the conveyance direction is detected by the controller 100 based on a detection signal from the document abutting sensor 42. That is, the abutting sensor 42 detects the leading edge of the document and turns on, and then the controller 100 generates a pulse signal of the paper feed motor 102 when the abutting sensor 42 detects the trailing edge of the document and turns off. By counting, the length of the document is detected.

  A reading entrance roller 45 is provided on the downstream side of the intermediate roller 43. The reading entrance roller 45 includes a driving roller 45 a and a driven roller 45 b and is driven by the reading motor 103.

  A white background plate 47 having a substantially U-shaped cross section is provided on the upper surface of the slit glass 131 so as to guide the conveyed document.

  A reading exit roller 48 is provided on the downstream side of the background plate 47. The reading exit roller 48 includes a driving roller 48a and a driven roller 48b.

  A second reading roller 49 is provided downstream of the reading exit roller 48. The second reading roller 49 is composed of a driving roller. A reading exit roller 50 is provided on the downstream side of the second reading roller 49. The reading exit roller 50 includes a driving roller 50a and a driven roller 50b. The reading entrance roller 45, the reading exit roller 48, the second reading roller 49, and the reading exit roller 50 are driven by a reading motor 103.

  An image sensor 51 such as a CCD or CIS is provided above the second reading roller 49. The image sensor 51 reads the other side of the document.

  An inlet sensor 46 is provided on the downstream side of the intermediate roller 43. The entrance sensor 46 outputs a signal to the controller 100 when the leading edge of the document is detected.

  When a signal is input from the entrance sensor 46, the controller 100 sets the document conveyance speed to be the same as the reading conveyance speed before the leading edge of the document enters the nip between the driving roller 45a and the driven roller 45b of the reading inlet roller 45. Therefore, simultaneously with the start of deceleration of the paper feed motor 102, the reading motor 103 is driven to rotate forward to connect the intermediate roller 43 to the driving system on the reading motor 103 side, and the reading inlet roller 45 and the reading outlet roller 48. The second reading roller 49 is driven.

  Further, when the original is conveyed from the registration unit 26 to the turn unit 27 by driving the abutting roller 41 and the intermediate roller 43, the conveyance speed at the registration unit 26 is higher than the conveyance speed at the first reading conveyance unit 28. By setting to, the processing time for feeding the document to the slit glass 131 is shortened, and the distance between the documents is shortened.

  A registration sensor 71 is provided on the downstream side of the reading entrance roller 45. The registration sensor 71 detects the leading edge of the document and outputs a signal to the controller 100.

  When a signal is input from the registration sensor 71, the controller 100 decelerates the paper feed motor 102 over a predetermined conveyance distance, temporarily stops the document in front of the slit glass 131, and sets the I / F 107. A registration stop signal is transmitted to the main body control unit 111 via the control unit 111. When the controller 100 receives a reading start signal from the main body control unit 111, the controller 100 increases the reading motor 103 so that the leading edge of the document whose registration is stopped rises to a predetermined conveyance speed before reaching the slit glass 131. The document is conveyed at high speed by the intermediate roller 43 and the reading entrance roller 45.

  When the controller 100 receives a reading start signal before the leading edge of the document reaches the registration sensor 71, the registration non-stop reading operation is performed. In the registration non-stop reading operation, the registration stop is not performed and the reading conveyance speed is increased. Reading is performed while being maintained.

  Further, a gate signal indicating an effective image area in the sub-scanning direction on the surface of the document is output to the main body control unit 111 at the timing when the leading edge of the document calculated by the pulse count of the reading motor 103 reaches the slit glass 131. It has become. The gate signal is continuously output until the trailing edge of the document passes through the slit glass 131.

  In the case of single-sided document reading, the document that has passed through the slit glass 131 is conveyed to the paper discharge unit 30 via the second reading conveyance unit 29. At this time, when the paper discharge sensor 74 detects the leading edge of the document, the paper discharge roller 73 is rotated counterclockwise by the normal rotation drive of the paper discharge motor 104.

  In addition, the controller 100 detects the leading edge of the document by the paper discharge sensor 74 and then counts the pulses of the paper discharge motor 104, so that the trailing edge of the document comes out from the nip between the drive roller 73a of the paper discharge roller 73 and the driven roller 73b. Immediately before, the driving speed of the paper discharge motor 104 is reduced to prevent the discharged original from jumping out of the stack portion 31.

  On the other hand, in the case of double-sided original reading, the controller 100 counts the pulses of the reading motor 103 after the leading edge of the original is detected by the paper discharge sensor 74 and the original calculated by the pulse count of the reading motor 103. The gate signal indicating the effective image area in the sub-scanning direction on the surface of the document is output to the image sensor 51 at the timing when the leading edge of the document reaches the slit glass 131. The gate signal is continuously output until the trailing edge of the document passes through the image sensor 51.

  The second reading roller 49 is white. This is because the second reading roller 49 is used as a reference white portion for acquiring shading data in the image sensor 51. A second reading roller 49 is provided below the image sensor 51. This is to suppress the floating of the original when the image sensor 51 reads.

  As shown in FIG. 2, the main body 21 of the copying machine 20 includes a cylindrical light source 77 formed of a xenon lamp or a halogen lamp, reflection mirrors 78a to 78c, a condensing lens 79, and an image sensor 80 such as a CCD. A reading unit 81 is provided, and image information read by the reading unit 81 is applied to the photosensitive drum 83 by the writing unit 82. The light source 77 includes a reflector 77a for improving the illuminance distribution on the document surface. The light source 77 is not limited to a xenon lamp or a halogen lamp, and a fluorescent lamp can also be used. The reading unit 81, the slit glass 131, and the frame 132 constitute an image reading apparatus according to the present invention.

  FIG. 4 is a configuration diagram of the image reading apparatus and the image forming unit of the image forming apparatus according to the first embodiment of the present invention.

  As shown in FIG. 4, around the photosensitive drum 83, a charging device 84 that forms an image forming unit together with the photosensitive drum 83, a writing unit 82 including a laser diode and the like, a potential sensor 85, A developing device 86, a transfer belt 87, a cleaning device 88, and a static eliminating device 89 including an LED (Light Emitting Diode) are provided. The charging device 84 controls the corona discharge with a positive charge by using a grid in the dark so as to charge the surface of the photosensitive drum 83 to a constant potential.

  The writing unit 82 irradiates a laser diode containing image information onto the photosensitive drum 83 charged to a constant potential, thereby removing negative charges on the photosensitive drum 83 and forming an electrostatic latent image. It is like that. The potential sensor 85 measures the potential on the photosensitive drum 83 and corrects it by process control.

  The developing device 86 forms a visible image by attaching a negatively charged toner to the electrically removed portion on the photosensitive drum 83. The transfer belt 87 is applied with a positive bias, and transfers a negatively charged visible image onto a recording paper (recording medium) for conveyance.

  The cleaning device 88 includes a cleaning blade 88a, and the toner remaining on the photosensitive drum 83 is scraped off by the cleaning blade 88a. The static eliminator 89 removes the residual charge on the photosensitive drum 83 by turning on the LED, and prepares to form a new image on the next recording sheet.

  The recording paper on which the toner image is formed by a series of these operations is conveyed to the fixing device 90, where the toner image is fixed on the recording paper by heat and pressure.

  As shown in FIG. 1, storage cassettes 91 to 95 in which recording papers S1 to S5 of different sizes are stored are provided in the main body 21. The recording sheets stored in the storage cassettes 91 to 95 are fed by the calling rollers 91a to 95a, and then slidably contact the sheet feeding rollers 91b to 95b and the sheet feeding rollers 91b to 95b that are rotated in the transport direction. Are separated by reverse rollers 91c to 95c, which are then rotated, and conveyed to a pair of registration rollers 98 via relay roller pairs 96 and 97, and are timed by the pair of registration rollers 98 so that the photosensitive drum 83 and the transfer belt 87 are It is conveyed to the conveyance path between.

  FIG. 5 is a configuration diagram of the image reading apparatus and the reading unit of the image forming apparatus according to the first embodiment of the present invention. FIG. 6 is an enlarged view of the image reading apparatus and the reading unit of the image forming apparatus according to the first embodiment of the present invention.

  As shown in FIGS. 5 and 6, the light source 77 and the reflection mirror 78 a are mounted on the first carriage 121, and the reflection mirrors 78 b and 78 c are mounted on the second carriage 122. The second carriage 122 is fixed to the drive wire 123.

  The drive wire 123 is supported by the driven pulleys 124 a and 124 b, one end of which is fixed to the main body 21, and the other end is fixed to the main body 21 via the tension spring 125.

  A part of the drive wire 123 is wound around a drive pulley 126, and this drive pulley 126 is connected to the motor shaft of the drive motor 128 via a drive transmission belt 127.

  When the book document is placed on the contact glass 22, the controller 100 drives the drive motor 128 and moves the drive wire 123 around the driven pulleys 124 a and 124 b via the drive transmission belt 127 and the drive pulley 126. Thus, the first carriage 121 and the second carriage 122 are moved in parallel with the contact glass 22 along a rail (not shown), and the light source 77 and the reflection mirrors 78a, 78b, and 78c are moved below the contact glass 22. It is set to read mode. Here, the book document is a book document that is opened.

  In the first reading mode, the first carriage 121 and the second carriage 122 move further to the right from the home position indicated by the solid line in FIG. 6 through the position indicated by the broken line, and return to the home position after the reading is completed. It is supposed to be. The first carriage 121 and the second carriage 122 move rightward along the document at a speed of 2: 1. That is, the second carriage 122 moves at a speed half that of the first carriage 121.

  In the second reading mode in which the document conveyed by the ADF 23 is read on the slit glass 131, the controller 100 moves the first carriage 121 and the second carriage 122 as shown by a solid line in FIG. The light source 77 and the reflection mirrors 78a, 78b, 78c are fixed below the slit glass 131 so as to read the original.

  A white reference plate 75 as a white reference member is provided on the upper surface of the end portion of the contact glass 22 adjacent to the slit glass 131. The white reference plate 75 is used for obtaining white level reference data when the reading unit 81 reads a document and correcting characteristic unevenness (shading correction) of the reading unit 81.

  The controller 100 drives the drive mechanism 109 to move the reading unit 81 from the reading position of the slit glass 131 toward the white reference plate 75 to read the white reference plate 75, and then reads the document at the reading position of the slit glass 131. These images are read, and the read image data is transferred to the main body control unit 111.

  The main body control unit 111 includes a CPU, a ROM, a RAM, and the like. Before reading a document conveyed to the slit glass 131 by the ADF 23, the main body control unit 111 reads the white reference plate 75 to correct characteristic unevenness (shading) of the reading unit 81. Correction).

  Here, the shading correction refers to reading the white reference plate 75 prior to reading a document, obtaining white level reference data as white data for shading correction of each pixel, and shading correction based on the obtained white reference data. Data is generated, correction processing is performed on image data of a document read using the correction data, and the image data is normalized.

  FIG. 7 is a perspective view of the slit glass of the image reading apparatus and the image forming apparatus according to the first embodiment of the present invention. FIG. 8 is an enlarged view of an end portion of the slit glass of the image reading apparatus and the image forming apparatus according to the first embodiment of the present invention.

  As shown in FIGS. 7 and 8, the slit glass 131 is supported by a metal frame 132. Specifically, the slit glass 131 is placed on an upper part of a metal frame 132 having an opening slightly smaller than the area of the slit glass 131 so as to cover the opening. Illumination of the original by the light source 77 and reading of reflected light from the original are performed through the slit glass 131. One end of the frame 132 in the longitudinal direction is fixed to the upper surface of the main body 21 by screws 142. Further, the other end portion in the longitudinal direction of the frame 132 is fixed to the upper surface of the main body 21 by a stepped screw 141 so that the other end portion in the longitudinal direction can move in the longitudinal direction. The peripheral edge of the slit glass 131 is covered from above by a holding member (not shown) made of resin or the like.

  The screw hole 132a of the frame 132 inserted through the stepped screw 141 has a width in the short direction of the frame 132 substantially equal to the outer diameter of the stepped screw 141, and the width in the longitudinal direction of the frame 132 is outside the stepped screw 141. It is formed in an oval shape larger than the diameter.

  For this reason, the end of the frame 132 on the side where the stepped screw 141 is inserted can move in the longitudinal direction of the frame 132 in accordance with the expansion and contraction of the frame 132.

  The shape of the screw hole 132a has a short axis substantially the same diameter as the stepped screw 141 in the short direction of the frame 132 and a long axis larger than the outer diameter of the stepped screw 141 in the longitudinal direction of the frame 132. It may have an elliptical shape. Further, the shape of the screw hole 132a has a short side substantially the same diameter as the stepped screw 141 in the short direction of the frame 132, and a long side larger than the outer diameter of the stepped screw 141 in the longitudinal direction of the frame 132. It may be a rectangular shape. That is, the shape of the screw hole 132a is such that the width in the short direction of the frame 132 is substantially equal to the outer diameter of the stepped screw 141 and the width in the longitudinal direction of the frame 132 is larger than the outer diameter of the stepped screw 141. For example, shapes other than those described above may be used.

  FIG. 9 is a sectional view of the slit glass of the image reading apparatus and the image forming apparatus according to the first embodiment of the present invention.

  As shown in FIG. 9, the frame 132 expands when it becomes high temperature due to heat from the light source 77 than when it is low temperature. For this reason, the end of the frame 132 on the side where the stepped screw 141 is inserted moves to the left side of FIG. 9 when the temperature of the frame 132 increases and expands, and when the temperature of the frame 132 decreases and contracts, Move to the right side of Therefore, a force that deforms the frame 132 upward or downward into a convex shape is not generated, and the frame 132 always maintains a linear shape.

  Next, the operation will be described.

  First, when the document bundle P is placed on the document table 24, the controller 100 changes the state in which the document set sensor 36 detects the set filler 35 to the non-detected state. The top surface of the bundle P is brought into contact with the pickup roller 37.

  Next, when the print key of the operation unit 108 is pressed, a document feed signal is transmitted from the main body control unit 111 to the controller 100 via the I / F 107. The controller 100 drives the paper feed motor 102 to rotate forward, thereby rotating the paper feed belt 39 in the clockwise direction and rotating the reverse roller 40 in the clockwise direction. For this reason, the uppermost original is separated from the original bundle P.

  Next, when the abutting sensor 42 detects the leading edge of the document before the registration sensor 71 receives the reading start signal, the controller 100 drives the paper feeding motor 102 by a predetermined distance to feed paper. A state in which the leading edge of the document is abutted against the abutting roller 41 by rotating the belt 39 and transporting the document by a predetermined distance, and the document is pressed with a predetermined amount of bending. To correct the skew of the original.

  Next, the controller 100 stops driving the paper feed motor 102, stops driving the pickup motor 101, rotates the pickup motor 101 again, and retracts the pickup roller 37 from the upper surface of the document bundle P.

  Next, the controller 100 drives the paper feed motor 102 in the reverse direction. At this time, the pickup roller 37 and the paper feed belt 39 are stopped, the abutting roller 41 and the intermediate roller 43 are driven, and the document is conveyed toward the slit glass 131.

  Next, when the leading edge of the document is detected by the entrance sensor 46, the controller 100 determines that the first document is separated and fed, and supplies the document in order to equalize the document conveyance speed and the reading conveyance speed. The paper motor 102 is driven at a reduced speed, and the leading edge of the document is abutted against the reading entrance roller 45 so that the document is pressed against the reading entrance roller 45 with a predetermined amount of bending. At the same time, the registration stop signal is transmitted to the main body control unit 111 via the I / F 107 with the position of the leading edge of the original at this time as the registration stop position.

  Next, when receiving a reading start signal, the controller 100 drives the reading motor 103 to rotate the reading entrance roller 45 and conveys the document toward the slit glass 131.

  Next, the controller 100 indicates the effective image area on the first surface in the sub-scanning direction to the main body control unit 111 at the timing when the leading edge of the document detected by the pulse count of the reading motor 103 reaches above the slit glass 131. Send a gate signal. The gate signal is continuously transmitted until the trailing edge of the document passes through the slit glass 131. In this way, one side of the document is read by the reading unit 81 provided below the slit glass 131.

  Prior to reading the first document, the controller 100 drives the first carriage 121 and the second carriage 122 by the driving mechanism 109 so that the light source 77 and the reflection mirrors 78a to 78c are indicated by broken lines in FIG. To the lower side of the white reference plate 75, the light source 77 is turned on to irradiate the white reference plate 75 with light from the light source 77, and the reflected light from the white reference plate 75 is condensed via the reflection mirrors 78a to 78c. After the light is condensed by the lens 79, it is read by the image sensor 80 to obtain white reference data for shading correction. Thereafter, the controller 100 drives the first carriage 121 and the second carriage 122 to move the light source 77 and the reflection mirrors 78a to 78c to the lower side of the slit glass 131 as indicated by solid lines in FIG. The original is read.

  Next, the controller 100 starts the feeding of the subsequent document placed on the document table 24 by reversing the sheet feeding motor 102. At this time, when the leading edge of the document is detected by the butting sensor 42, the controller 100 conveys the document by a predetermined distance.

  Next, when the leading edge of the document passes through the abutting roller 41, the controller 100 drives the paper feed motor 102 to rotate forward to stop the rotation of the abutting roller 41 and the intermediate roller 43. At this time, the intermediate roller 43 Is driven at substantially the same linear speed as a reading conveyance system roller such as the reading entrance roller 45 by the driving of the reading motor 103. At this time, the leading edge of the subsequent document is abutted against the abutting roller 41 to correct the skew.

  Here, in the case of single-sided document reading, the document that has passed through the first reading and conveying unit 28 is conveyed to the paper discharge unit 30 through the second reading and conveying unit 29. When the leading edge of the paper is detected, the paper discharge motor 104 is driven to rotate forward to rotate the paper discharge roller 73 counterclockwise.

  In addition, the controller 100 counts the pulses of the paper discharge motor 104 after the paper discharge sensor 74 detects the leading edge of the original, so that the rear end of the original is the driving roller 73a of the paper discharge roller 73 and the driven roller 73b. Immediately before leaving the nip, the drive speed of the paper discharge motor 104 is reduced so that the original discharged to the stack unit 31 does not jump out.

  In the second reading mode, when the document conveyed by the reading unit 81 is continuously read, the light source 77 is continuously turned on in order to keep the illuminance of the light source 77 constant. When the light source 77 is continuously turned on, the frame 132 is heated to expand due to the heat of the light source 77, but the end of the frame 132 on the side where the stepped screw 141 is inserted is the expansion of the frame 132. Since the frame 132 can move in the longitudinal direction according to the contraction, a force that deforms the frame 132 upward or downward into a convex shape is not generated, and the frame 132 always maintains a linear shape. .

  As described above, the image reading apparatus according to the present embodiment includes the screw 142 that fixes one end portion of the frame 132 in the longitudinal direction to the main body 21 so that the one end portion does not move in the longitudinal direction and the short direction of the frame 132. The slit glass 131 is supported since the other end portion in the longitudinal direction of the frame 132 is provided with the stepped screw 141 and the screw hole 132a for fixing the other end portion to the main body 21 so that the other end portion can move in the longitudinal direction of the frame 132. One end of the frame 132 in the longitudinal direction is fixed to the main body 21 by a screw 142 so that the one end does not move in the longitudinal direction and the short direction of the frame 132, and the other end in the longitudinal direction of the frame 132 is fixed to the stepped screw 141. And the screw hole 132 a are fixed to the housing so that the other end can move in the longitudinal direction of the frame 132. When the temperature of the 2 rises to thermal expansion, the other longitudinal end of the frame 132 because it can move longitudinally, never frame 132 is convex curved. Therefore, the frame 132 that supports the slit glass 131 can be prevented from being deformed by the heat generated by the light source 77. In addition, since the frame 132 is not curved and has a convex shape, the frame 132 is in contact with other members such as the first carriage 121 and the second carriage 122 in the vicinity, and the position of the slit glass 131 is shifted. Can be prevented.

  Further, the image reading apparatus according to the present embodiment is provided with a stepped screw 141 screwed into the main body 21 and the frame 132, and the width of the frame 132 in the short direction is substantially equal to the outer diameter of the stepped screw 141. Since the other end in the longitudinal direction of the frame 132 is fixed to the main body 21 by the screw hole 132a formed and having a width in the longitudinal direction of the frame 132 larger than the outer diameter of the stepped screw 141, the frame 132 is fixed. Since the width of the screw hole 132a in the longitudinal direction is larger than the outer diameter of the stepped screw 141, the other end in the longitudinal direction of the frame 132 even if the frame 132 expands in the longitudinal direction due to the heat of the light source 77 Since the width of the screw hole 132a in the short direction of the frame 132 is formed substantially equal to the outer diameter of the stepped screw 141, It is possible to maintain the lateral direction of the position of the frame 132 to be constant. Therefore, the position of the frame 132 can be kept constant, and the frame 132 can be prevented from being deformed by the heat generated by the light source 77.

  Further, in the image reading apparatus according to the present embodiment, since the frame 132 is made of metal, expansion and plastic deformation due to heat can be reduced as compared with the case where the frame 132 is made of resin or the like.

In addition, since the image forming apparatus according to the present embodiment includes the image reading device having the above-described configuration, the frame 132 that supports the slit glass 131 can be prevented from being deformed by the heat generated by the light source 77. .
(Second Embodiment)
FIG. 10 is an enlarged view of an end portion of the slit glass of the image reading apparatus and the image forming apparatus according to the second embodiment of the present invention. In addition, the same code | symbol is attached | subjected to the structure similar to 1st Embodiment, and description is abbreviate | omitted.

  As shown in FIG. 10, an engagement protrusion 132 c is provided at one end of the frame 132 of the slit glass 131, and an engagement hole 21 a is formed on the upper surface of the main body 21 to engage the engagement protrusion 132 c. Note that the other end of the frame 132 is fixed to the upper surface of the main body 21 by screws 142 as in the first embodiment. That is, in the present embodiment, an engagement protrusion 132c and an engagement hole 21a are provided in place of the stepped screw 141 and the screw hole 132a in the first embodiment.

  The engaging hole 21a of the main body 21 with which the engaging protrusion 132c is engaged has a width in the short direction of the frame 132 substantially equal to the width of the engaging protrusion 132c, and the width in the longitudinal direction of the frame 132 is larger than the thickness of the frame 132. Is also formed in a large oval shape.

  For this reason, the end of the frame 132 on the side where the stepped screw 141 is inserted can move in the longitudinal direction of the frame 132 in accordance with the expansion and contraction of the frame 132.

As described above, the image reading apparatus according to the present embodiment includes the screw 142 that fixes one end portion of the frame 132 in the longitudinal direction to the main body 21 so that the one end portion does not move in the longitudinal direction and the short direction of the frame 132. Since the other end portion in the longitudinal direction of the frame 132 is provided with the engagement protrusion 132c and the engagement hole 21a for fixing the other end portion to the main body 21 so that the other end portion can move in the longitudinal direction of the frame 132, Therefore, when the temperature of the frame 132 rises and the thermal expansion occurs, the other end portion in the longitudinal direction of the frame 132 can move in the longitudinal direction, so that the frame 132 is not curved and has a convex shape. Therefore, the frame 132 that supports the slit glass 131 can be prevented from being deformed by the heat generated by the light source 77. In addition, since the frame 132 is not curved and has a convex shape, the frame 132 is in contact with other members such as the first carriage 121 and the second carriage 122 in the vicinity, and the position of the slit glass 131 is shifted. Can be prevented.
(Third embodiment)
FIG. 11 is a top view of the slit glass of the image reading apparatus and the image forming apparatus according to the third embodiment of the present invention. FIG. 12 is an enlarged view of an end portion of the slit glass of the image reading apparatus and the image forming apparatus according to the third embodiment of the present invention. In addition, the same code | symbol is attached | subjected to the structure similar to 1st Embodiment and 2nd Embodiment, and description is abbreviate | omitted.

  As shown in FIGS. 11 and 12, in the present embodiment, one end of the frame 132 in the longitudinal direction (the right end in FIG. 11) is fixed to the main body 21 with a screw 142, and the other end in the longitudinal direction of the frame 132 ( In the left end portion of FIG. 11, a cut 132e is formed so that the frame 132 is divided in the lateral direction. Further, the side closer to the light source 77 than the notch 132 e of the frame 132 is screwed to the upper surface of the main body 21 with a stepped screw 141. Further, the side far from the light source 77 with respect to the notch 132e of the frame 132 is fixed to the upper surface of the main body 21 with screws 142.

  The screw hole 132a of the frame 132 inserted through the stepped screw 141 has a width in the short direction of the frame 132 substantially equal to the outer diameter of the stepped screw 141, and the width in the longitudinal direction of the frame 132 is outside the stepped screw 141. It is formed in an oval shape larger than the diameter.

  For this reason, the end of the frame 132 on the side where the stepped screw 141 is inserted can move in the longitudinal direction of the frame 132 in accordance with the expansion and contraction of the frame 132.

  That is, in the first embodiment, in the first embodiment, the notch 132e is formed at the other longitudinal end of the frame 132 so that the frame 132 is divided in the short direction, and the light source is more light than the notch 132e of the frame 132. The side closer to 77 is screwed to the upper surface of the main body 21 with a stepped screw 141, and the side farther from the light source 77 than the notch 132 e of the frame 132 is fixed to the upper surface of the main body 21 with screws 142.

  The side close to the light source 77 of the frame 132 receives heat from the light source 77 and expands at a high temperature, and the side far from the light source 77 remains at a low temperature and thus hardly expands. The end is divided in the short direction, and only one end on the side close to the light source 77 of the frame 132 can move in the longitudinal direction.

  FIG. 13 is a top view illustrating another example of the slit glass of the image reading apparatus and the image forming apparatus according to the third embodiment of the present invention.

  As shown in FIG. 13, notches 132e and 132f may be formed at both ends in the longitudinal direction of the frame 132 so that the frame 132 is divided in the lateral direction.

  FIG. 14 is an enlarged view showing another example of the end portion of the slit glass of the image reading apparatus and the image forming apparatus according to the third embodiment of the present invention.

  As shown in FIG. 14, an engagement protrusion 132 c is formed at one end of the frame 132, an engagement hole 21 a for engaging the engagement protrusion 132 c is formed on the upper surface of the main body 21, and the other end of the frame 132 is You may comprise so that it may fix to the upper surface of the main body 21 with the screw | thread 142. FIG.

  As described above, in the image reading apparatus according to the present embodiment, the frame 132 is divided in the short direction of the frame 132 at one or both ends in the longitudinal direction of the frame. It is possible to prevent the frame 132 from being deformed by a temperature difference between the side closer to the light source 77 and the side farther from the light source 77.

  Further, in the image reading apparatus according to the present embodiment, the stepped screw 141 and the screw hole 132a as the second fixing means, or the engaging protrusion 132c and the engaging hole 21a as the second fixing means are divided. Since the frame 132 is arranged on the side close to the light source 77, it is the side near the light source 77 among the divided frames 132 that expands due to heat from the light source 77. Since the other longitudinal end of 132 can move, the frame 132 can be prevented from being deformed.

  As described above, the image reading apparatus and the image forming apparatus according to the present invention have an effect that the support member that supports the slit glass can be prevented from being deformed by the heat generated by the light source, such as a scanner apparatus. The present invention is useful as an image reading apparatus, an image reading apparatus such as a copying machine, a facsimile machine or the like equipped with the image reading apparatus.

1 is a schematic configuration diagram of an image reading apparatus and an image forming apparatus according to a first embodiment of the present invention. 1 is a schematic configuration diagram of an ADF of an image reading apparatus and an image forming apparatus according to a first embodiment of the present invention. 1 is a block diagram of a drive system of an image reading apparatus and an image forming apparatus according to a first embodiment of the present invention. 1 is a configuration diagram of an image forming unit of an image reading apparatus and an image forming apparatus according to a first embodiment of the present invention. 1 is a configuration diagram of an image reading apparatus and a reading unit of an image forming apparatus according to a first embodiment of the present invention. 1 is an enlarged view of an image reading apparatus and a reading unit of an image forming apparatus according to a first embodiment of the present invention. 1 is a perspective view of a slit glass of an image reading apparatus and an image forming apparatus according to a first embodiment of the present invention. 1 is an enlarged view of an end portion of a slit glass of an image reading apparatus and an image forming apparatus according to a first embodiment of the present invention. 1 is a cross-sectional view of a slit glass of an image reading apparatus and an image forming apparatus according to a first embodiment of the present invention. It is an enlarged view of the edge part of the slit glass of the image reading apparatus and image forming apparatus which concern on the 2nd Embodiment of this invention. It is a top view of the slit glass of the image reading apparatus and image forming apparatus which concern on the 3rd Embodiment of this invention. It is an enlarged view of the edge part of the slit glass of the image reading apparatus and image forming apparatus which concern on the 3rd Embodiment of this invention. It is a top view which shows the other example of the slit glass of the image reading apparatus which concerns on the 3rd Embodiment of this invention, and an image forming apparatus. It is an enlarged view which shows the other example of the edge part of the slit glass of the image reader which concerns on the 3rd Embodiment of this invention, and an image forming apparatus. It is a perspective view of the slit glass of the conventional image reading apparatus. (A) is sectional drawing of the slit glass at the time of the normal temperature of the conventional image reading apparatus, (b), (c) is sectional drawing of the slit glass at the time of the high temperature of the conventional image reading apparatus.

Explanation of symbols

20 Copying machine (image forming device)
21 Body (Housing)
23 Slit glass 77 Light source 81 Reading unit (reading means, image reading device)
131 Slit glass 132 Frame 132a Screw hole (second fixing means)
141 Stepped screw (second fixing means)
142 screw (first fixing means)

Claims (5)

A slit glass in contact with the document;
A support member for supporting the slit glass;
A light source that illuminates the document through the slit glass;
In an image reading apparatus comprising reading means for reading reflected light from the original,
First fixing means for fixing one end of the support member in the longitudinal direction to the housing so that the one end does not move in the longitudinal direction and the short direction of the support member;
A second fixing means for fixing the other end in the longitudinal direction of the support member to the housing so that the other end can move in the longitudinal direction of the support member ;
The support member is divided in the lateral direction of the support member at the other end in the longitudinal direction of the support member;
One divided in the short direction at the other end in the longitudinal direction of the support member is fixed by the second fixing means,
The other divided in the short direction at the other end in the longitudinal direction of the support member is fixed by the first fixing means,
One end of the supporting member in the longitudinal direction is fixed by the first fixing means . A slit glass in contact with the document;
A support member for supporting the slit glass;
A light source that illuminates the document through the slit glass;
In an image reading apparatus comprising reading means for reading reflected light from the original,
First fixing means for fixing one end of the support member in the longitudinal direction to the housing so that the one end does not move in the longitudinal direction and the short direction of the support member;
A second fixing means for fixing the other end in the longitudinal direction of the support member to the housing so that the other end can move in the longitudinal direction of the support member;
The support member is divided in the short direction of the support member at the other end and the one end in the longitudinal direction of the support member,
One divided in the short direction at the other end in the longitudinal direction of the support member is fixed by the second fixing means,
The other divided in the short direction at the other end in the longitudinal direction of the support member is fixed by the first fixing means,
An image reading apparatus according to claim 1, wherein one and the other of the support member divided in the longitudinal direction at one end in the longitudinal direction are fixed by the first fixing means . A slit glass in contact with the document;
A support member for supporting the slit glass;
A light source that illuminates the document through the slit glass;
In an image reading apparatus comprising reading means for reading reflected light from the original,
First fixing means for fixing one end of the support member in the longitudinal direction to the housing so that the one end does not move in the longitudinal direction and the short direction of the support member;
A second fixing means for fixing the other end in the longitudinal direction of the support member to the housing so that the other end can move in the longitudinal direction of the support member;
The support member is divided in a short direction of the support member;
Of the one divided in the short direction of the support member, the other end in the longitudinal direction is fixed by the second fixing means,
One end of the longitudinal direction of the one divided in the short direction of the support member is fixed by the first fixing means,
Of the other divided in the short direction of the support member, the other end in the longitudinal direction is fixed by the first fixing means,
An image reading apparatus, wherein one end portion in the longitudinal direction of the other of the support members divided in the short direction is fixed by the first fixing means . The second fixing means includes an oval engagement hole formed in the housing and having a long diameter in the longitudinal direction of the support member, and an engagement protrusion formed in the support member and engaged with the engagement hole. the image reading apparatus according to any one of claims 1 to 3, characterized in that composed. An image forming apparatus comprising the image reading apparatus according to claim 1 .

Images