JP2014222837A - Image reading device and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image reading device that can suppress the backlash of a scanning unit and reduce the size of the device, and an image forming apparatus.SOLUTION: One drive wire 141 is folded multiple times around first to fourth pulleys 142a to 142d in a housing to form a plurality of wire parts laid over from one end to the other end in the sub scanning direction; the drive wire 141 is disposed so that the first wire part 141a on one end side in the main scanning direction, and the third wire part 141c on the other end side move in the same direction; and the first wire part 141a is fixed to one end in the main scanning direction of a scanning unit 40, and the third wire part 141c is fixed to the other end of the scanning unit 40.

Description

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

  2. Description of the Related Art Conventionally, there has been known an image forming apparatus including an image reading device that irradiates light on a document, images the document with an image sensor based on reflected light from the document, and reads an image of the document (for example, patent References 1, 2).

FIG. 15 is a schematic configuration diagram of the image reading apparatus described in Patent Document 1, FIG. 15A is a plan view, and FIG. 15B is a front view.
In the image forming apparatus described in Patent Document 1, as shown in FIG. 15A, a first drive wire 203a is provided at one end of the frame 213 in the main scanning direction (vertical direction in the figure). A second drive wire 203b different from the first drive wire 203a is provided at the other end of the frame 213 in the main scanning direction (vertical direction in the figure). One end of the first carriage 201 and the second carriage 202 is fixed to the first drive wire 203a, and the other end of the first carriage 201 and the second carriage 202 is fixed to the second drive wire 203b. . One end of each drive wire 203a, 203b is fixed to the left side wall of the frame 213 in the figure. As shown in FIG. 15B, the drive wires 203a and 203b are sequentially wound around the pulley 204b and the first idler pulley 204a of the second carriage 202 from the side wall of the frame 213. Next, it is wound around the drive pulley 205 several times, and further wound around the second idler pulley 204c and the pulley 204a of the second carriage, and the other end is fixed in the frame body 213 via the spring 207. Yes.

  In the image reading apparatus described in Patent Document 1, both ends of the main scanning direction (FIG. 15A) are arranged so that the carriages 201 and 202 do not tilt in the sub-scanning direction (left-right direction in FIG. 15A) when moving. It is necessary to drive the drive wires 203a and 203b provided in the vertical direction at the same timing and at the same speed. Therefore, in Patent Document 1, the drive shaft 206 that receives the driving force from the drive motor 210 is provided from one end to the other end of the frame 213 in the main scanning direction, and the drive pulley 205 is fixed near both ends of the drive shaft 206. . Thereby, each drive wire 203a, 203b can be driven at the same timing and the same speed.

FIG. 16 is a schematic configuration diagram of an image reading apparatus described in Patent Document 2.
The image reading apparatus described in Patent Document 2 uses a single endless drive wire 303 to drive a carriage 301 that is a scanning unit. Specifically, the drive wire 303 is wound around the drive pulley 304 arranged at one end (left side in the figure) in the sub-scanning direction (left and right direction in the figure) which is the scanning direction of the carriage 301. The drive wire 303 wound around the drive pulley 304 is wound around the first folding pulley 305 disposed at the other end (right side in the drawing) in the sub-scanning direction and folded back. Next, the direction of the drive wire 303 is changed in the main scanning direction (vertical direction in the figure) by a first idler pulley 306 disposed at one end (left side in the figure) in the sub-scanning direction. The drive wire 303 whose direction is changed by the first idler pulley 306 is changed again in the sub-scanning direction by the second idler pulley 307. Next, after being wound around the second folding pulley 308 disposed at the other end in the sub-scanning direction (right side in the figure), the direction is changed in the main scanning direction by the tension pulley 309, and the driving pulley 304 is turned. It is rolled up.

  A portion of the frame that is spanned between the one end and the other end in the sub-scanning direction as the moving direction spanning portion of the drive wire 303 is, in order from the top in the figure, the first wire portion 303a, the second wire portion 303b, Assuming that the third wire portion 303c and the fourth wire portion 303d are used, the carriage 301 is fixed to the second wire portion 303b and the fourth wire portion 303d.

  When the drive motor 310 is driven to rotate the drive pulley 304, the second and fourth wire portions 303b and 303d move from the left side to the right side in the drawing, and the first and third wire portions 303a and 303c are shown in the drawing. Move from right to left. Since the carriage 301 is fixed to the second and fourth wire portions 303b and 303d, the first carriage 301 is pulled by the second and fourth wire portions 303b and 303d and moves from the left side to the right side in the drawing. As a result, the carriage 301 moves along the document surface.

  The second wire portion 303b fixed to one side across the center of the carriage 301 in the main scanning direction (broken line A in the figure) and the fourth wire portion 303d fixed to the other side are the same drive wire. . Therefore, if the drive pulley 304 is rotated, the second wire portion 303b and the fourth wire portion 303d move at the same timing and the same speed. Therefore, one side and the other side of the carriage 301 can be pulled at the same timing and at the same speed, and the carriage 301 does not tilt in the sub-scanning direction.

  In the image reading apparatus described in Patent Document 1, as described above, in order to drive the drive wires 203a and 203b at the same timing and at the same speed, from one end to the other end of the frame 213 in the main scanning direction. An extending drive shaft 206 needs to be provided. In addition, it is necessary to wind the drive wire a plurality of times, and it is necessary to arrange two drive pulleys 205 having a larger diameter than other pulleys.

  On the other hand, in the image reading apparatus described in Patent Literature 2, one drive wire pulls one side and the other side across the center in the main scanning direction of the carriage 301 so that it has a larger diameter than the other pulleys. One drive pulley can be used. Further, it is not necessary to extend the drive shaft from one end to the other end of the frame 213 in the main scanning direction. Therefore, the size of the apparatus can be reduced as compared with the image reading apparatus described in Patent Document 1.

  However, in the image reading apparatus described in Patent Document 2, the carriage 301 may move while rattling. This is because, in the image forming apparatus described in Patent Document 2, the drive wire 303 pulls the center side of the carriage in the main scanning direction as shown in FIG. More specifically, the closer the pulling portion of the carriage 301 by the drive wire 303 is to the central portion in the main scanning direction, the closer the carriage rotates in the vertical direction (a direction perpendicular to both the sub-scanning direction and the main scanning direction). It becomes easy to turn. When the carriage 301 is moved, for example, there is a difference between the sliding resistance between the guide rail that guides one end of the carriage 301 and the carriage 301, and the sliding resistance between the guide rail that guides the other end of the carriage 301 and the carriage 301. Sometimes. As described above, when a difference occurs in the sliding resistance, a force that rotates in the vertical direction when the carriage 301 moves is generated. Therefore, in the configuration in which the central portion of the carriage 301 in the main scanning direction is pulled by the drive wire as in the image reading device described in Patent Document 2, if a difference in sliding resistance occurs as described above, the carriage There is a possibility that 301 may rotate and move while rattling. As described above, when the carriage 301 moves with rattling, the read image is deteriorated. For this reason, it is preferable to pull the both ends of a carriage with a drive wire as much as possible.

  Therefore, in the image reading apparatus described in Patent Document 2, it is conceivable that one end and the other end of the carriage 301 in the main scanning direction are fixed to the driving wire, and both ends of the carriage 301 in the main scanning direction are pulled by the driving wire. However, in the image reading apparatus described in Patent Document 2, the moving directions of the first wire portion 303a on one end side in the main scanning direction and the fourth wire portion 303d on the other end side in the main scanning direction are different from each other. Therefore, when one end and the other end of the carriage in the main scanning direction are fixed to the drive wire, the first wire portion 303a or the fourth wire portion 303d is disposed outside the end portion of the carriage 301 in the main scanning direction. Become. As a result, there arises a problem that the image reading apparatus is increased in size in the main scanning direction.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an image reading apparatus and an image forming apparatus that can suppress backlash during movement of a scanning unit and can be downsized. That is.

  In order to achieve the above object, the invention of claim 1 includes a scanning unit that includes at least illumination means for irradiating light on a document surface, and is supported by the housing so as to be movable along the document surface. A single linear member is bent back multiple times by a plurality of pulleys to form a plurality of moving direction extending portions that extend from one end to the other end of the scanning unit in the casing, and the moving direction extending portion An image reading device comprising: a plurality of moving direction transfer portions that move in the same direction, fixed to the scanning unit, and moving means that moves the scanning unit along the document surface via the linear member. In the apparatus, in the arrangement direction of the extending portions of the linear members, the linear direction is such that the moving direction extending portion on one end side is the same as the moving direction of the moving direction extending portion on the other end side. The member is arranged and the above An end-side moving direction extending portion is fixed to one end of the linear unit extending portions of the scanning unit in the arrangement direction, and the other end-side moving direction extending portion is fixed to the linear member of the scanning unit. It is characterized by being fixed to the other end in the arrangement direction of the spanning portion.

  According to the present invention, it is possible to suppress rattling during movement of the scanning unit and to reduce the size of the apparatus.

1 is a schematic configuration diagram of an entire copying machine according to an embodiment. The perspective view which shows an image reading apparatus. The schematic block diagram which shows an integrated scanning unit. The schematic block diagram which shows a moving mechanism. The schematic block diagram of the 1st modification of a moving mechanism. Schematic configuration diagram of drive pulley The schematic block diagram of the 2nd modification of a moving mechanism. The schematic block diagram of the 3rd modification of a moving mechanism. FIG. 9 is an overall configuration diagram of a copier that is provided with an image reading apparatus provided with a moving mechanism according to a third modification. The schematic block diagram which shows a tension maintenance mechanism. (A) is a figure explaining the case where the fixing location of the fixing member with the integrated scanning unit is other than the plane projection position in the main scanning direction of the center of gravity of the integrated scanning unit. FIG. 6B is a diagram for explaining a case where the fixing position of the fixing member with the integrated scanning unit is set as a plane projection position in the main scanning direction of the center of gravity of the integrated scanning unit. FIG. 4 is a diagram in which a fixing portion of the fixing member with the integrated scanning unit is at a plane projection position in the main scanning direction of the center of gravity of the integrated scanning unit, and the drive wire passes through the fixing portion. The figure which shows the structure which urges | biases an integrated scanning unit to a rail with the tension | tensile_strength of a drive wire. The figure which shows the structure which separated the wire fixing member which fixes a drive wire to an integrated scanning unit, and the tension maintenance mechanism, respectively. Schematic which shows the conventional image reading apparatus. Schematic of other conventional image reading apparatus.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
First, a basic configuration example of the copying machine 1 as an image forming apparatus according to the present embodiment will be described.
FIG. 1 is a cross-sectional view showing the internal configuration of the copying machine 1 according to the present embodiment. The copying machine 1 of FIG. 1 includes an image reading device 17 and an image forming unit 11. The copying machine 1 includes yellow (hereinafter referred to as Y), cyan (hereinafter referred to as C), magenta (hereinafter referred to as M), and black. This is a color image forming apparatus that forms one image from four-color toner (hereinafter referred to as BK).
The image forming unit 11 includes an image forming unit 12 that forms a toner image on a recording medium, a fixing device 13 that fixes the toner image on the recording medium formed by the image forming unit 12 to the recording medium, and an image forming unit 12. And a recording medium conveying device 14 for feeding the recording medium.

  The copying machine 1 includes an image reading device 17 that reads a document image, and an automatic document transport device 18 (referred to as ADF) having a pressure plate function as an opening / closing member that transports the document. The automatic document feeder 18 is mounted on the image reading device 17 through a hinge mechanism (not shown) so as to be freely opened and closed.

  The automatic document feeder 18 is separated from a document placing table 20 on which a document bundle can be placed, a contact position where the document bundle placed on the document placing table 20 is brought into contact with the upper surface of the document bundle, and a document bundle. And a pickup roller 21 that moves between the separated positions. Further, a document conveying means comprising a sheet feeding belt 22, a reverse roller 23, and a conveying roller pair 24 that separates the documents one by one from the bundle of documents sent out by the pickup roller 21 and conveys them toward the slit glass 36 that is a reading position. 25. Further, a document discharge unit 29 including a conveyance roller pair 27 and a discharge roller pair 28 for discharging a document, which has been read at the reading position, to the document discharge table 26 is provided.

  The paper discharge roller pair 28 includes a drive roller 28a, a driven roller 28b and a driven roller 28c that are in sliding contact with the drive roller 28a, and a switching claw 30 is provided in the vicinity of the paper discharge roller pair 28. The switching claw 30 moves between the first switching position and the second switching position. When the switching claw 30 is switched to the first switching position, the driving roller 28a and the driven roller 28b The document is discharged to the document discharge table 26. When the switching claw 30 is switched to the second switching position, the document is conveyed to the switchback passage 31 by the driving roller 28a and the driven roller 28c.

  The switchback passage 31 is provided with a pair of switchback rollers 32 that can rotate forward and backward. The document conveyed to the switchback path 31 is conveyed in the right direction in FIG. 1 by the switchback roller pair 32, and then the switchback roller pair 32 is driven in reverse so that the conveyance roller pair passes through the reconveying path. It is conveyed to 24. For this reason, the document is reversed and conveyed to the reading position.

  As is known per se, the image reading device 17 includes a housing 17a that houses the optical system 34, and a contact glass 35 and a slit glass 36 that are fixedly disposed on the top of the housing 17a. In the image reading device 17, a document including a closed document or a book is placed on the contact glass 35, and the document is read by pressing the document by the automatic document feeder 18. be able to. A document automatically conveyed by the automatic document conveying device 18 is read at the reading position of the slit glass 36.

  The image forming unit 12 includes a first image carrier 45Y, a second image carrier 45C, a third image carrier 45M, and a fourth image carrier 45BK made of a drum-shaped photoconductor. An intermediate transfer belt 46 composed of an endless belt wound around a plurality of support rollers is disposed opposite to the first to fourth image carriers 45Y to 45BK. The first to fourth image carriers 45Y to 45BK are respectively rotated in the clockwise direction in FIG. 1, and the intermediate transfer belt 46 is rotated in the direction of arrow A in FIG. At this time, the first image carrier 45Y is charged to a predetermined polarity by the charging roller 47.

  The optical writing unit 48 emits a laser beam L that is optically modulated based on the image signal corresponding to the result of reading the document. By irradiating the charged surface of the first image carrier 45Y with the laser beam L, an electrostatic latent image is formed on the first image carrier 45Y. This electrostatic latent image can be converted into a yellow toner image by the developing device 49. Visualized.

  When a transfer voltage is applied to the primary transfer roller 50, the toner image formed on the first image carrier 45Y is primarily transferred onto the intermediate transfer belt 46 that rotates in the direction of arrow A in FIG. . The transfer residual toner adhering to the first image carrier 45Y after the toner image transfer is removed by the cleaning device 52. In the copying machine 1 of the present embodiment, the first image carrier 45Y, the charging roller 47 disposed around the first image carrier 45Y, the developing device 49, and the cleaning device 52 constitute an integral process cartridge. Yes.

  The developing device 49 has a developing container 53 containing powdered toner, and the electrostatic latent image is visualized by the toner. Further, when the toner amount in the developing container 53 decreases, the toner is supplied to the developing container 53 from the toner bottle 54Y.

  On the other hand, the cleaning device 52 includes a cleaning container 55 that receives the toner removed from the first image carrier 45Y. The toner in the cleaning container 55 is transported to a waste toner container (not shown) by the toner transport device. Is done. As described above, the developing container 53, the toner bottle 54Y, the cleaning container 55, and the waste toner container contain toner.

  In the same manner as described above, a cyan toner image, a magenta toner image, and a black toner image are formed on the second image carrier 45C, the third image carrier 45M, and the fourth image carrier 45BK, respectively. These toner images are primarily transferred onto the intermediate transfer belt 46 onto which the yellow toner image has been transferred in sequence.

  When the toner amount in the developing container of the developing device for forming the toner image on the second image carrier 45C, the third image carrier 45M, and the fourth image carrier 45BK decreases, the toner bottles 54C, 54M, From 54BK, toner is supplied to each developer container.

  In this manner, the superimposed toner image transferred onto the intermediate transfer belt 46 is secondarily transferred onto the recording medium by the action of the secondary transfer roller 56, and the transfer residual toner attached on the intermediate transfer belt 46 after the transfer. Is removed by the belt cleaning device 52. The cleaning container 55 of the cleaning device 52 also stores toner, and the toner is conveyed to a waste toner container (not shown).

  The recording medium transport device 14 is disposed below the intermediate transfer belt 46, and the recording medium transport device 14 includes a paper feed cassette 57 that stores a recording medium S made of recording paper or the like, and a top recording medium S. A sheet feeding roller 58 and a registration roller pair 59 are in contact with each other. The uppermost recording medium S is sent out in the direction of arrow B in FIG. The sent recording medium S is fed between the intermediate transfer belt 46 and the secondary transfer roller 56 disposed opposite to the intermediate transfer belt 46 at a predetermined timing by the rotation of the registration roller pair 59.

  When the recording medium S passes between the intermediate transfer belt 46 and the secondary transfer roller 56, a transfer voltage is applied to the secondary transfer roller 56, so that the superimposed toner image on the intermediate transfer belt 46 is recorded on the recording medium. Secondary transfer. In this way, a toner image is formed on the recording medium S by the image forming means 12.

  Then, the recording medium S on which the toner image is formed passes through the fixing device 13, and at this time, the toner image on the recording medium S formed by the image forming unit 12 is fixed to the recording medium S. The recording medium S on which the image is fixed by the fixing device 13 is discharged into the discharge space 61 by the discharge roller pair 60.

The paper discharge space 61 is formed between the image forming unit 11 and the image reading device 17. In the present embodiment, the in-body discharge type copier 1 in which the space between the image forming unit 11 and the image reading device 17 on the downstream side in the discharge direction of the recording medium S by the discharge roller pair 60 is opened.
Further, a switching lever 62 is provided on the upstream side of the discharge roller pair 60. When the copying on the front surface of the recording medium is completed, the switching lever 62 is used when copying on the back surface of the recording medium S. It can be switched to the reversing passage 63 side.

  That is, when the rear end of the recording medium S is sandwiched between the paper discharge roller pair 60, the paper discharge roller pair 60 is driven in reverse, and the switching lever 62 is switched to a position communicating with the reverse passage 63. It is conveyed toward the reversing passage 63.

  A reversing roller pair 64 is provided in the reversing path 63, and the recording medium conveyed through the reversing path 63 by the reversing roller pair 64 is conveyed to the secondary transfer roller 56 side. On the other hand, a reflective guide plate 65 is provided on the slit glass 36, and the reflective guide plate 65 reflects light from the light source unit 401 described later.

  Further, a guide member 71 is provided between the contact glass 35 and the slit glass 36 so that the guide member 71 scoops up the document that has passed through the slit glass 36 and guides it toward the conveying roller pair 27. It has become.

  FIG. 2 is a perspective view showing the image reading device 17. Although not shown in the figure for convenience, an automatic document feeder 18 is mounted on the image reading device 17 and is supported by a hinge so as to be swingable. The upper surface of 17 can be opened and closed. On the upper surface of the image reading device 17, a contact glass 35 and a slit glass 36 are provided as transparent members.

FIG. 4 is a schematic configuration diagram showing the integrated scanning unit 40.
As shown in FIG. 4, in the frame 407 of the integrated scanning unit 40, a light source unit 401 is stored as a light irradiating means including a light source such as a xenon lamp and an inverter circuit board that controls lighting of the light source. . Also stored are five reflecting mirrors 402a, 402b, 402c, 402d, and 402e that refract the reflected light from the document as the imaging object, and an imaging lens unit 403 that condenses the reflected light from these reflecting mirrors. Yes. In addition, an image sensor 405 serving as an imaging unit that photoelectrically converts the light collected by the imaging lens unit 403, and a drive that drives the image sensor 405 and outputs an image signal based on an electrical signal output from the image sensor 405. A circuit board 406 and the like are also stored.

  The imaging lens unit 403 includes a first group lens 403a disposed on the reflection mirror 402e side and a second group lens 403b disposed on the image sensor 405 side. The first group lens 403a is a lens having a positive power, and the second group lens 403b is a lens having a negative power. In the present embodiment, the first group lens 403a is composed of a single lens, but is composed of a plurality of (for example, 2 to 4) lenses including one or more lenses having positive power. Also good. By forming the imaging lens unit 403 with a first group lens 403a having a positive power and a second group lens 403b having a negative power, chromatic aberration is corrected and an image with a high resolution is applied to the image sensor 405. An image can be formed. Further, the focal length can be shortened, and the integrated scanning unit 40 can be made compact. Furthermore, the so-called back focus, which is the distance from the second group lens 403b to the image sensor 405, can be shortened, and the integrated scanning unit 40 can be made compact.

  The first group lens 403a and the second group lens 403b are held by a lens base 409. The drive circuit board 406 on which the image sensor 405 is mounted is attached to the lens receiving base 409 via the fixed bracket 410. As the image sensor 405, a charge-coupled device (CCD) or a complementary metal oxide semiconductor (CMOS) can be used.

Next, the moving mechanism 140 that moves the integrated scanning unit 40, which is a characteristic part of the present embodiment, in the sub-scanning direction will be described.
4A and 4B are schematic configuration diagrams showing the moving mechanism 140. FIG. 4A is a plan view, FIG. 4B is a side view, and FIG. 4C is a front view.
As shown in FIG. 4, in the moving mechanism 140, pulleys 142a, 142b, 142c, 142d are arranged at the four corners of the bottom surface of the housing 17a. Each pulley is disposed in the housing 17a so that the rotation axis thereof is in a direction perpendicular to the bottom surface of the housing 17a. An endless drive wire 141 is wound around these pulleys 142a to 142d. Specifically, as shown in FIG. 4A, the drive wire 141 wound around the first pulley 142a disposed on the lower left side in the figure is connected to the second pulley disposed on the lower right side in the figure. 142b is folded toward the third pulley 142c disposed at the upper left in the drawing. Next, the drive wire 141 is folded back toward the fourth pulley 142d disposed at the upper right in the drawing by the third pulley 142c, and then folded back toward the first pulley 142a by the fourth pulley 142d.

  One of the first to fourth pulleys 142a to 142d is a driving pulley that is driven to rotate by receiving a driving force from a driving motor (not shown). In this embodiment, the drive wire is moved endlessly by the frictional force between the drive pulley and the drive wire.

  As shown in FIG. 4A, the region of the drive wire 141 spanned between the first pulley 142a and the second pulley 142b is hung on the first wire portion 141a, the second pulley 142b, and the third pulley 142c. The transferred area is defined as a second wire portion 141b. Further, a region of the drive wire 141 spanned between the third pulley 142c and the fourth pulley 142d is a third wire portion 141c, and a region spanned between the fourth pulley 142d and the first pulley 142a is a fourth wire portion. 141d. As described above, when the drive wire 141 is defined, in the present embodiment, the drive wire 141 is disposed so that the second wire portion 141b and the fourth wire portion 141d intersect each other. Thus, by arranging the drive wire 141, as shown in FIG. 4A, four wire portions 141a spanned between one end and the other end in the sub-scanning direction (left-right direction in the figure). The moving direction of the outermost first wire part 141a and the third wire part 141c can be the same direction in the ~ 141d part.

  One end (lower side in the drawing) of the main scanning direction (vertical direction in the drawing) of the bottom surface of the integrated scanning unit 40 is fixed to the first wire portion 141a of the drive wire 141. Further, the other end (lower side in the figure) of the main scanning direction (vertical direction in the figure) of the bottom surface of the integrated scanning unit 40 is fixed to the third wire part 141c moving in the same direction as the first wire part 141a.

  The third wire portion 141c of the drive wire 141 is provided with a tension spring 108 for applying a predetermined tension to the drive wire 141. The tension spring 108 is disposed at a position facing the integrated scanning unit 40. When the tension spring 108 is disposed at a position other than this position, the tension spring 108 hits the pulleys 142d and 142c during the movement of the integrated scanning unit 40. If the pulleys 142d and 142c are arranged so that the tension spring 108 does not collide with the pulleys 142d and 142c, the image reading device 17 is increased in size in the sub-scanning direction. Therefore, the tension spring 108 is disposed at a position facing the integrated scanning unit 40. Accordingly, the pulleys 142d and 142c can be disposed close to the moving range of the integrated scanning unit 40, and the image reading apparatus can be prevented from being enlarged in the sub-scanning direction. The tension spring 108 may be provided on the second wire portion 141b or the fourth wire portion 141d, and the tension spring 108 may be provided in consideration of maintenance and the like.

  As shown in FIGS. 4B and 4C, the integrated scanning unit 40 is mounted on rails 41 provided at both ends of the casing 17a in the main scanning direction. Specifically, support portions 40b provided so as to protrude from the side surfaces are provided on both side surfaces of the integrated scanning unit 40 in the main scanning direction. Two resin shoes 40a as members for reducing friction with the rail 41 are provided on the lower surface of the support portion 40b with a predetermined interval in the sub-scanning direction. The resin shoe 40a is formed of a slidable synthetic resin such as POM, nylon, PPS, or PEEK. These resin shoes 40a move while contacting the rail 41.

  When any one of the first to fourth pulleys 142a to 142d is rotationally driven and the drive wire is moved endlessly, the integrated scanning unit 40 is pulled by the first wire portion 141a and the third wire portion 141c of the drive wire. The As a result, the integrated scanning unit 40 moves on the rail 41 and reads the image of the document S on the contact glass 35.

  The integrated scanning unit 40 moves while sliding on rails provided at both ends in the main scanning direction. At this time, if the sliding resistance between the rail on the one end side and the integrated scanning unit is different from the sliding resistance between the rail on the other end side and the integrated scanning unit, the integrated scanning unit 40 will move rattlingly. become. Such rattling is more likely to occur as the portion pulled by the drive wire is closer to the center in the main scanning direction. Therefore, in order to suppress such backlash at the time of movement, it is preferable to pull both ends of the integrated scanning unit in the main scanning direction as much as possible with the drive wires 141.

  In the present embodiment, the outermost of the four wire portions 141a to 141d that crosses the drive wire 141 at one location and spans between one end and the other end in the sub-scanning direction (left-right direction in the figure). The moving directions of the first wire portion 141a and the third wire portion 141c are the same. Accordingly, the outermost first wire portion 141 a and third wire portion 141 c can be fixed to the integrated scanning unit 40 and used as a wire portion that pulls the integrated scanning unit 40. Further, even if the first wire portion 141a is fixed to one end of the integrated scanning unit 40 and the third wire portion 141c is fixed to the other end of the integrated scanning unit, there is no wire portion outside this. Therefore, the length of the image reading device 17 in the main scanning direction can be made substantially the length of the integrated scanning unit in the main scanning direction, and the size of the device can be reduced. In addition, since both ends of the integrated scanning unit 40 can be pulled with a wire, the integrated scanning unit can be moved smoothly without rattling.

  Further, both ends of the integrated scanning unit 40 can be pulled by a single drive wire. Thus, the first wire portion 141a and the third wire portion 141c fixed to the integrated scanning unit 40 can pull the integrated scanning unit 40 at the same timing and the same speed. Thereby, it is possible to prevent the integrated scanning unit from skewing when the integrated scanning unit is moved.

  Further, as described above, each pulley is disposed in the housing 17a so that the rotation axis thereof is in a direction perpendicular to the bottom surface of the housing 17a. Thereby, the position accuracy of the height direction of the 1st wire part 141a and the 3rd wire part 141c can be taken out easily. However, in this case, the drive wires rub against each other at the intersection of the second wire portion 141b and the fourth wire portion 141d. Therefore, the first pulley 142a and the fourth pulley 142d may be provided to be inclined with respect to the bottom surface of the housing 17a, and the fourth wire portion 141d may be separated from the second wire portion 141b in the vertical direction.

  In the above description, one drive wire 141 is arranged endlessly. For example, one end of the drive wire 141 is fixed to the first pulley 142a and the other end is fixed to the fourth pulley 142d. Also good. In the case of such a configuration, the first pulley 142a and the fourth pulley 142d are unwound and can be taken up. When the scanning unit 40 is in the standby position, the drive wire 141 is wound around the first pulley 142a a plurality of times. When the scanning unit 40 is moved from the standby position, the drive wire 141 is wound up by the fourth pulley 142d, and the drive wire 141 is wound up by the first pulley 142a. Accordingly, the scanning unit 40 can be moved from the standby position by being pulled by the first wire portion 141a and the third wire portion 141c. When the scanning unit reaches the end opposite to the standby position. The drive wire 141 is wound up by the first pulley 142a, and the drive wire 141 is wound up by the fourth pulley 142d. Accordingly, the scanning unit can be moved toward the standby position while being pulled by the drive wire.

  In the above description, the drive wire is endlessly moved by the frictional force between the drive pulley and the drive wire. However, the drive wire may be moved by winding it at the same time as winding the drive wire.

FIG. 5 is a diagram showing a moving mechanism 140 provided with a drive pulley that moves the drive wire by winding and unwinding the drive wire. FIG. 5A is a plan view, and FIG. 5B is a side view.
As shown in FIG. 5, the drive pulley 143 is provided between the second pulley 142b and the third pulley 143c. A timing pulley 144a is provided coaxially with the drive pulley 143. A timing belt 144 is stretched between the timing pulley 144a and a drive shaft 145a of a drive motor 145 provided outside the housing 17a. Yes.

FIG. 6 is a schematic configuration diagram of the drive pulley 143. 6A is a cross-sectional view of the drive pulley 143, and FIG. 6B shows the integrated scanning unit 40 positioned at one end in the sub-scanning direction of the housing 17a (the left end in FIG. 5). It is a figure which shows the drive pulley 143 at the time. FIG. 6C shows the drive pulley 143 when the integrated scanning unit 40 is located at the other end in the sub-scanning direction of the housing 17a (the right end in FIG. 5).
As shown in FIG. 6A, a part of the drive wire 141 is fixed to the drive pulley 143 by a fastening member 143a. The drive wire 141 is wound around the drive pulley 143 at least by the same distance as the moving distance of the integrated scanning unit 40 from the fixed position with the drive pulley 143.

  When the drive motor 145 is driven from the state shown in FIG. 6B to drive the drive pulley 143 to rotate, the drive wire 141 closer to the second pulley 142b than the drive pulley 143 is wound around the drive pulley 143. At the same time, the wire 141 wound around the drive pulley 143 is unwound toward the third pulley 142c. As a result, the drive wire 141 moves endlessly, and the integrated scanning unit 40 is pulled by the first and third wire portions 141a and 141c and moves from one end side to the other end side in the sub-scanning direction of the housing 17a. . When the integrated scanning unit 40 moves to the other end side in the sub-scanning direction of the housing 17a, the drive motor 145 stops and the drive pulley 143 enters the state shown in FIG. When the drive motor 145 is rotated in the reverse direction from the state shown in FIG. 6C, the drive wire 141 on the third pulley 142c side is wound around the drive pulley 143, and at the same time, the wire 141 wound around the drive pulley 143 is It is unwound toward the second pulley 142b. Accordingly, the integrated scanning unit 40 moves from the other end in the sub-scanning direction of the housing 17a toward one end.

  As described above, by using the drive pulley 143 that moves the drive wire 141 by fixing a part of the drive wire 141 and winding the drive wire 141 at the same time, the following advantages can be obtained. That is, when a drive pulley that moves the drive wire 141 by frictional force with the drive wire 141 is used, the drive wire 141 may slide with respect to the drive pulley, and the moving speed of the integrated scanning unit 40 may vary. is there. On the other hand, the above-described slip does not occur by using the drive pulley 143 that moves the drive wire 141 by winding the drive wire 141 at the same time as winding. Thereby, the integrated scanning unit can be stably moved, and a good read image can be obtained.

  As shown in FIGS. 6B and 6C, the unwinding and winding positions of the driving pulley 143 change in the vertical direction as the driving pulley 143 rotates. When one of the pulleys 142a to 142d arranged at the four corners of the housing 17a is used as the drive pulley 143 shown in FIG. 6, the first wire portion 141a or the third wire portion 141c to which the integrated scanning unit 40 is fixed is provided. As the integrated scanning unit 40 moves, it moves up and down. As a result, the integrated scanning unit 40 cannot be stably moved, and the read image may be deteriorated. Therefore, when the drive pulley 143 shown in FIG. 6 is used as the drive pulley 143, it is provided separately from the pulleys arranged at the four corners of the casing 17a. Further, it is provided between the spanning region between the second pulley 142b and the third pulley 142c or the spanning region between the fourth pulley 142d and the first pulley 142a. Thereby, it is possible to prevent the first wire portion 141a and the third wire portion 141c to which the integrated scanning unit 40 is fixed from moving up and down when the integrated scanning unit 40 moves. Thereby, the integrated scanning unit can be moved stably, and a good read image can be obtained.

  Depending on the apparatus, a sensor or a control board may be disposed on the bottom surface of the image reading apparatus 17. In that case, in the configuration shown in FIG. 6, an electric element or a sensor on the control board may hit the fourth wire portion 141d. In such a case, for example, as shown in FIG. 7, a pulley 142e is appropriately added so that the drive wire 141 does not hit the electric element or sensor of the control board arranged on the bottom surface of the image reading device 17. Just place it.

  Further, as shown in FIG. 8, the drive pulley 143 may be directly attached to the drive shaft of the drive motor 145. In this case, the length in the vertical direction of the portion where the drive motor 145 of the housing 17a is provided is longer than the other portions. In this case, as shown in FIG. 9, the drive pulley 143 is disposed so as to be positioned above the paper discharge unit of the image forming unit 11. The image reading device support portion above the paper discharge portion of the image forming unit 11 is provided with a recess for fitting a portion protruding downward by the drive motor 145 of the image reading device 17. A portion protruding downward by the drive motor 145 of the image reading device 17 is fitted into the recess, and the image reading device 17 is supported by the image forming unit 11. As a result, as shown in FIG. 9, it is possible to prevent the in-body discharge space 61 of the copying machine 1 from being narrowed by a portion protruding downward by the drive motor 145 of the image reading device 17. As a result, the portion protruding downward by the drive motor 145 of the image reading device 17 does not get in the way when the recording paper discharged to the paper discharge space 61 is taken out.

  In the present embodiment, as shown in FIGS. 4 and 5, the third wire portion 141c is provided with a tension spring 108 that applies a prescribed tension to the drive wire 141. When the integrated scanning unit 40 is moved from the standby position, the inertial force of the integrated scanning unit 40 acts on the tension spring 108 to extend the tension spring. As a result, the tension of the drive wire 141 is lowered, the drive wire 141 is loosened, and the start of movement of the integrated scanning unit 40 is delayed. As a result, the position of the image copied on the recording paper in the sub-scanning direction may be deviated from the original image. Further, when the integrated scanning unit 40 starts to move, the inertial force decreases at a stretch, and the tension spring 108 vibrates. As a result, the tension of the drive wire 141 varies, and the moving speed of the integrated scanning unit 40 is not stable. As a result, the image copied on the recording paper is deteriorated.

Therefore, in this embodiment, a tension maintaining mechanism that maintains the tension of the drive wire 141 constant may be provided.
FIG. 10 is a schematic configuration diagram showing the tension maintaining mechanism 120.
The tension maintaining mechanism 120 includes a fixing member 121 for fixing one end of the tension spring 108 and the drive wire 141 to the integrated scanning unit 40. The tension maintaining mechanism 120 includes a tension maintaining member 123 that maintains the tension of the drive wire 141 at a specified value.

  The fixing member 121 is fixed to the integrated scanning unit 40 by a fixing screw 122. One end of the tension spring 108 is hooked on the spring hooking portion 121 a of the fixing member 121, and the other end is hooked on the spring hooking portion 123 a of the tension maintaining member 123. The fixing member 121 has a wire fixing portion 121b, and one end of the drive wire 141 is fixed to the wire fixing portion 121b.

  Although not shown, the tension maintaining member 123 has a wire fixing portion to which the other end of the drive wire 141 is fixed. The tension maintaining member 123 is attached to the fixing member 121 via a tension fixing screw 124 so as to be slidable in the direction of arrow C in the figure. Specifically, a through hole 123b (a through hole on the back side is not shown) through which the tension fixing screw 124 passes is provided on the front and back side surfaces of the tension maintaining member 123 in the drawing. These through holes 123b are elongated holes extending in the direction of arrow C in the figure. The tension fixing screw 124 is screwed into a screw hole (not shown) provided in the fixing member 121.

  The tension fixing screw 124 is tightened in a state where the tension of the drive wire 141 is a predetermined value by the urging force of the tension spring 108. Thereby, the tension maintaining member 123 is clamped and fixed by the tension fixing screw 124 and the fixing member 121 so as not to move in the direction of arrow C in the figure. In this manner, the tension of the drive wire 141 can be fixed to a predetermined tension simply by tightening the tension fixing screw 124. Accordingly, the tension maintaining member 123 can be easily fixed as compared with the case where the tension maintaining member 123 is fixed in a state where the tension maintaining member 123 is pulled by hand and the driving wire 141 has a predetermined tension. .

  By fixing the tension maintaining member 123 to the integrated scanning unit 40 via the fixing member 121, the following advantages can be obtained. That is, when the drive wire 141 is driven, it is transmitted to the integrated scanning unit 40 via the tension maintaining member 123, and the driving force is not transmitted to the tension spring 108. Therefore, the inertial force of the integrated scanning unit 40 acts on the tension maintaining member 123 and does not act on the tension spring 108. As described above, since the inertia force is not applied to the tension spring 108 by the tension maintaining member 123, the tension spring 108 does not extend due to the inertia force of the integrated scanning unit 40. As a result, the tension of the drive wire 141 is not lowered by the inertial force of the integrated scanning unit 40, and the drive wire 141 is not loosened. As a result, the driving force is satisfactorily transmitted to the integrated scanning unit 40, and it is possible to prevent the movement start of the integrated scanning unit 40 from being delayed by the inertial force of the integrated scanning unit 40. As a result, it is possible to prevent the position of the image copied on the recording paper in the sub-scanning direction from deviating from the original image. Further, since the tension spring 108 does not vibrate due to the inertial force of the integrated scanning unit 40, the tension of the drive wire 141 does not fluctuate. Accordingly, the moving speed of the integrated scanning unit 40 is stabilized, and a document image can be read satisfactorily. Thus, in this embodiment, even if the inertial force of the integrated scanning unit 40 is applied to the drive wire 141, the tension of the drive wire 141 can be maintained at a constant tension without fluctuation.

  Further, in the conventional configuration that does not include the tension maintaining mechanism 120, the urging force of the tension spring decreases with age, and the tension of the drive wire 141 may decrease. On the other hand, in the present embodiment, since the tension maintaining member 123 is fixed with a specified tension, the specified tension can be maintained over time.

  Further, when the tension maintaining member 123 is fixed with the tension fixing screw 124 in a state where the tension of the drive wire 141 is a predetermined value, the tension spring 108 may be removed. Further, after the tension maintaining member 123 is moved using a pulling jig so that the tension of the drive wire 141 becomes a predetermined value, the tension maintaining member 123 is fixed by the tension fixing screw 124. Even in this case, the tension of the drive wire 141 can be maintained at a specified value.

  In the present embodiment, the driving wire 141 is fixed to the integrated scanning unit 40 using the fixing member 121 of the tension maintaining mechanism 120. Thus, the number of parts can be reduced and the cost of the apparatus can be reduced as compared with the case where the drive wire 141 is fixed to the integrated scanning unit 40 by a member different from the tension maintaining mechanism 120.

In addition, it is preferable that the fixing position of the fixing member 121 with the integrated scanning unit 40 is a plane projection position in the main scanning direction of the center of gravity of the integrated scanning unit 40. The reason for this will be described with reference to FIG.
FIG. 11A is a diagram for explaining a case where the fixing part 121 is fixed to the integrated scanning unit 40 at a position other than the plane projection position of the center of gravity of the integrated scanning unit 40 in the main scanning direction. FIG. 11B is a diagram for explaining a case where the fixing position of the fixing member 121 to the integrated scanning unit 40 is set to the main scanning direction plane projection position of the center of gravity of the integrated scanning unit 40.
When the drive wire 141 is driven, the integrated scanning unit 40 is pulled in the moving direction (right side in the figure) at a fixed position between the fixing member 121 and the integrated scanning unit 40. Therefore, as shown in FIG. 11A, when the fixing portion of the fixing member 121 to the integrated scanning unit 40 is other than the plane projection position in the main scanning direction of the center of gravity of the integrated scanning unit 40, the integrated scanning unit. A moment as shown in FIG. As a result, there is a risk that the integrated scanning unit 40 may have a problem such as tilting and moving. On the other hand, as shown in FIG. 11 (b), when the fixing position of the fixing member 121 with the integrated scanning unit 40 is at the plane projection position in the main scanning direction of the center of gravity of the integrated scanning unit 40, the integrated scanning unit. When moving 40, no moment is generated. Thereby, the integrated scanning unit 40 can be moved horizontally, and a good read image can be obtained.

  However, in the configuration shown in FIG. 11B, when the drive wire 141 is moved, a moment is generated that causes the fixing member 121 to rotate around the fixing position. For this reason, as shown in the figure, it is preferable to provide a rotation restricting portion 131 that restricts the rotation of the fixing member 121 to restrict the rotation of the fixing member 121. Thereby, the influence of vibration of the integrated scanning unit 40 resulting from the rotation of the fixing member 121 can be reduced.

  Further, as shown in FIG. 12, the fixing portion of the fixing member 121 to the integrated scanning unit 40 is at the plane projection position in the main scanning direction of the center of gravity of the integrated scanning unit 40, and the drive wire 141 is used to It is good also as a structure which passes. With this configuration, when the integrated scanning unit 40 is moved, no moment is generated in either the fixing member 121 or the integrated scanning unit 40.

  Further, as shown in FIG. 13, the integrated scanning unit 40 may be biased to the rail 41 by the tension of the drive wire 141. More specifically, the fixing position of the integrated scanning unit 40 with the drive wire 141 is provided above the pulleys 142a, 142b, 142c, 142d arranged at the four corners of the housing 17a. As a result, the integrated scanning unit 40 is biased to the rail 41 by the tension of the drive wire 141. With this configuration, the integrated scanning unit 40 can be reliably moved along the rail 41. Thereby, it is possible to prevent the integrated scanning unit 40 from vibrating in the vertical direction when the integrated scanning unit 40 travels, and it is possible to improve scanning stability.

  Further, as shown in FIG. 14, the wire fixing member 151 that fixes the driving wire 141 to the integrated scanning unit 40 and the tension maintaining mechanism 120 may be provided separately. As described above, the wire fixing member 151 fixed to the integrated scanning unit 40 and the tension maintaining mechanism 120 are separately provided, so that the drive wire 141 can be easily assembled to the integrated scanning unit 40. Can do. Also in the configuration shown in FIG. 14, when the drive wire 141 is moved, a moment that causes the wire fixing member 151 to rotate around the fixed position is generated. For this reason, a rotation restricting portion 131 that restricts the rotation of the wire fixing member 151 is provided to restrict the rotation of the wire fixing member 151. Thereby, the influence of the vibration of the integrated scanning unit 40 caused by the rotation of the wire fixing member 151 can be reduced.

What has been described above is an example, and the present invention has a specific effect for each of the following aspects.
(Aspect 1)
The scanning unit 40 that includes at least an illumination unit such as a light source unit 401 that irradiates light on the document surface, is supported by the housing 17a so as to be movable along the document surface, and a line such as one drive wire 141 in the housing. A moving direction such as a wire portion in which the member is folded back by a plurality of pulleys (first to fourth pulleys 142a to 142d in the present embodiment) and spanned from one end to the other end of the scanning unit 40 in the housing. A plurality of spanning portions are formed (in the present embodiment, the first to fourth wire portions 141a to 141d), and a plurality of moving direction spanning portions that move in the same direction among the moving direction spanning portions are provided to the scanning unit 40. In the image reading apparatus 17 having a moving unit such as a moving mechanism 140 that moves the scanning unit 40 along the document surface through the linear member, the linear member is fixed. In the arrangement direction of the parts (main scanning direction), the movement direction spanning part on one end side such as the first wire part 141a and the movement direction of the movement direction bridging part on the other end side such as the third wire part 141c are the same. The linear member is arranged so as to be in the same direction, the moving direction extending portion on one end side is fixed to one end in the arrangement direction of the extending portion of the linear member of the scanning unit 40, and the moving direction hanging portion on the other end side is fixed. The delivery part was fixed to the other end in the arrangement direction of the delivery parts of the linear members of the scanning unit 40.
According to the aspect 1, as described in the present embodiment, unlike the image reading device described in Patent Document 2, the movement direction spanning portion (on the one end side of the moving direction spanning portion in the arrangement direction (main scanning direction) ( A linear member such as the drive wire 141 is disposed so that the first wire portion 141a) and the moving direction spanning portion (third wire portion 141c) on the other end side move in the same direction. Therefore, the moving direction spanning portion on the one end side can be fixed to one end of the scanning unit 40 in the main scanning direction, and the moving direction spanning portion on the other end can be fixed to the other end. As a result, unlike the image reading apparatus described in Patent Document 2 in which the moving direction of the moving direction extending portion on the one end side in the main scanning direction and the moving direction of the extending portion on the other end side are different from each other, When the moving direction spanning portion fixed to the moving unit and the moving direction spanning portion moving in the same direction are fixed to the other end of the scanning unit, the moving direction spanning portion is disposed outside the main scanning direction end portion of the scanning unit. It can be made non-existent. As a result, the length of the image reading apparatus 2 in the main scanning direction can be made substantially equal to the length of the scanning unit 40 in the main scanning direction. Therefore, as described in Patent Document 2, it is possible to reduce the size of the image reading apparatus in the main scanning direction as compared with the case where a linear member is provided.
In addition, since the extending portion of the linear member is fixed to one end and the other end of the scanning unit 40 in the main scanning direction, both ends of the scanning unit in the main scanning direction are pulled by the linear member. Thereby, as described in the embodiment, it is possible to suppress the scanning unit from moving while rattling.

(Aspect 2)
In (Aspect 1), the linear members such as the drive wires 141 are arranged so as to intersect at one place in the housing 17a.
By adopting such a configuration, as described in the embodiment, the moving direction spanning portion (in this embodiment, the first wire portion 141a and the third wire portion 141c) fixed to the scanning unit 40 is moved to the other direction. The direction spanning portion (in the present embodiment, the second and fourth wire portions 141b and 141d) can be located outside the moving direction spanning portion in the arrangement direction (main scanning direction).

(Aspect 3)
In (Aspect 2), the linear member such as the drive wire 141 includes a first pulley 142a disposed on one end side in the moving direction of the scanning unit of the housing 17a and one end side in the arranging direction of the moving direction extending portion. A first wire portion 141a or the like that is stretched over the other end side in the movement direction of the scanning unit 40 of the housing 17a and the second pulley 142b that is disposed at one end side in the arrangement direction of the movement direction spanning portion. It is stretched between the moving direction spanning portion, the second pulley 142b and the third pulley 142c disposed at one end side in the moving direction of the scanning unit 40 of the housing 17a and at the other end side in the arranging direction of the moving direction spanning portion. The second moving direction spanning portion such as the second wire portion 141b, the third pulley 142c, and the other end side in the moving direction of the scanning unit 40 of the housing 17a, and the other end in the arranging direction of the moving direction spanning portion The third wire direction 141c, such as the third wire portion 141c, spanned between the fourth pulley 142d, and the fourth pulley 142d, the first pulley 142a, and the second travel direction The scanning unit 40 is fixed to the first movement direction spanning section and the third movement direction spanning section.
With this configuration, as described in the embodiment, the moving direction spanning portion (in this embodiment, the first wire portion 141a and the third wire portion 141c) fixed to the scanning unit 40 by four pulleys. However, it can be arranged outside the moving direction spanning portion (main scanning direction) outside the other moving direction spanning portions (in the present embodiment, the second and fourth wire portions 141b and 141d).

(Aspect 4)
In any one of (Aspect 1) to (Aspect 3), among the plurality of pulleys, the drive pulley 143 that drives a linear member such as the drive wire 141 fixes a part of the linear member, and The linear member is wound a plurality of times.
With this configuration, as described in the embodiment, the scanning unit can be stably moved at a specified speed, and a good read image can be obtained.

(Aspect 5)
In (Aspect 3), among the plurality of pulleys, the driving pulley that drives the linear member fixes a part of the linear member and winds the linear member a plurality of times. The drive pulley 143 is disposed between the second pulley 142b and the third pulley 142c, or between the fourth pulley 142d and the first pulley 142a.
With this configuration, as described in the embodiment, the first moving direction spanning section such as the first wire section 141a to which the scanning unit 40 is fixed, and the third moving direction hanging section such as the third wire section 141c are provided. It is possible to suppress the passing portion from fluctuating in the vertical direction. Thereby, the scanning unit 40 can be moved stably.

(Aspect 6)
Also, in any one of (Aspect 1) to (Aspect 5), even if the inertial force of the scanning unit 40 is applied to a linear member such as the drive wire 141, the tension maintaining mechanism that maintains the tension of the linear member at a specified tension. Tension maintaining means such as 120 is provided.
By providing such a configuration, it is possible to prevent a change in the density of the read image as described in the embodiment.

(Aspect 7)
In (Aspect 6), the tension maintaining unit such as the tension maintaining mechanism 120 includes one end fixing unit such as a fixing member 121 that fixes one end of a linear member such as the drive wire 141 to the scanning unit 40, and a linear member. The other end fixing means (this book) fixes the other end of the linear member to the scanning unit in a state in which a predetermined tension is applied to the linear member by pulling the other end with a tension means such as a tension spring 108 or a tension jig. In the embodiment, a tension maintaining member 123 and a fixing screw 124 are provided.
By adopting such a configuration, as described in the embodiment, even if an inertial force of the scanning unit 40 is generated, the tension of the linear member such as the drive wire 141 can be maintained at a predetermined tension.

(Aspect 8)
In (Aspect 7), the tension means is a tension spring 108, one end is fixed to the scanning unit 40, the other end is fixed to the other end fixing means, and the other end fixing means is a drive wire 141 or the like. A tension adjusting member such as a tension maintaining member 123 that fixes the other end of the linear member and the other end of the tension spring 108 and is movable within a predetermined range in the biasing direction of the tension spring 108 with respect to the scanning unit 40; The linear member is provided with a fixing member such as a tension fixing screw 124 for fixing the tension adjusting member to the scanning unit 40 in a state where a prescribed tension is applied.
By providing such a configuration, as described in the embodiment, the tension adjusting member such as the tension maintaining member 123 is attached to the scanning unit 40 in a state where the linear member such as the drive wire 141 is maintained at a predetermined tension by the tension spring 108. Can be fixed to. This makes it easier to pull the tension adjusting member by hand and maintain the linear member at the prescribed tension and fix the tension adjusting member, with the linear member being at the prescribed tension. The tension adjusting member can be fixed to the scanning unit.

(Aspect 9)
In any one of (Aspect 1) to (Aspect 8), the scanning unit of the linear member fixing means has linear member fixing means such as a fixing member 121 for fixing a linear member such as the drive wire 141 to the scanning unit 40. The fixed portion with 40 is set as the main scanning plane projection position of the center of gravity of the scanning unit 40.
By providing such a configuration, it is possible to prevent the integral scanning unit 40 from being inclined and moving as described with reference to FIG.

(Aspect 10)
In any one of (Aspect 1) to (Aspect 9), the rotation that restricts the rotation of the linear member fixing means such as the fixing member 121 that fixes the linear member such as the drive wire 141 to the scanning unit 40 around the main scanning direction. A rotation restricting means such as a restricting portion 131 is provided.
By providing such a configuration, as described in the embodiment, it is possible to reduce the influence of vibration and the like due to the rotation of the linear member fixing means such as the fixing member 121 when the integrated scanning unit 40 travels.

(Aspect 11)
In any one of (Aspect 1) to (Aspect 10), even if the inertial force of the scanning unit is applied to the linear member such as the drive wire 141, the tension maintaining mechanism 120 or the like that maintains the tension of the linear member at a predetermined tension. A tension maintaining means is provided, and the tension maintaining means is provided with linear member fixing means such as a wire fixing portion 121b for fixing the linear member to the scanning unit.
By providing such a configuration, compared to a case where tension maintaining means such as the tension maintaining mechanism 120 and linear member fixing means for fixing the linear member such as the drive wire 141 to the integrated scanning unit 40 are provided separately, The number of parts can be reduced. Thereby, the cost of the apparatus can be reduced.

(Aspect 12)
In any one of (Aspect 1) to (Aspect 10), even if the inertial force of the scanning unit 40 is applied to a linear member such as the drive wire 141, the tension maintaining mechanism 120 that maintains the tension of the linear member at a predetermined tension. Tension maintaining means, and the tension maintaining means and the linear member fixing means for fixing the linear member to the scanning unit are provided separately.
With such a configuration, it is possible to easily assemble a linear member such as the drive wire 141 to the scanning unit 40.

(Aspect 13)
In any one of (Aspect 1) to (Aspect 12), the scanning unit 40 includes an image sensor.
By providing such a configuration, it is possible to reduce the size in the vertical direction as compared with a differential mirror type image reading apparatus.

(Aspect 14)
In any one of (Aspect 1) to (Aspect 13), a guide member such as a rail 41 that guides the travel of the scanning unit 40 with the tension of the linear member by fixing the scanning unit 40 and a linear member such as the drive wire 141. The scanning unit 40 is biased to the side.
By providing such a configuration, as described with reference to FIG. 13, it is possible to suppress the integrated scanning unit 40 from vibrating in the vertical direction when the integrated scanning unit 40 travels, and to improve scanning stability. Can be improved.

(Aspect 15)
In an image forming apparatus such as a copying machine including an image reading apparatus 17 that reads an image of a document and an image forming unit 11 that forms an image based on a reading result by the image reading apparatus 17, the image reading apparatus 17 is configured as (Aspect 1). The image reading apparatus according to any one of (Aspect 14) is used.
With this configuration, a high-quality image can be copied.

(Aspect 16)
In (Aspect 15), the image forming unit 11 discharges recording paper on the upper surface from a paper discharge unit provided so as to protrude from one end of the upper scanning unit in the moving direction. Is supported by a support portion provided on the paper discharge portion, and has a paper discharge space between the upper surface of the image forming unit 11 and the image reading device 17, and among the plurality of pulleys, a drive wire 141 and the like are provided. A driving pulley for driving the linear member was disposed above the paper discharge unit of the image forming unit 11.
With this configuration, as described in the embodiment, the in-body discharge space 61 of the copying machine 1 is prevented from being narrowed by a portion protruding downward by the drive motor 145 of the image reading device 17. Can do. As a result, the portion protruding downward by the drive motor 145 of the image reading device 17 does not get in the way when the recording paper discharged to the paper discharge space 61 is taken out.

1: Copier 11: Image forming unit 17: Image reading device 17a: Housing 35: Contact glass 36: Slit glass 40: Integrated scanning unit 40a: Resin shoe 40b: Support portion 41: Rail 61: Paper discharge space portion 108 : Tension spring 120: tension maintaining mechanism 121: fixing member 121a: spring hooking part 121b: wire fixing part 122: fixing screw 123: tension maintaining member 123a: spring hooking part 123b: through hole 124: tension fixing screw 131: rotation regulation Portion 140: Moving mechanism 141: Drive wire 141a: First wire portion 141b: Second wire portion 141c: Third wire portion 141d: Fourth wire portion 142a: First pulley 142b: Second pulley 142c: Third pulley 142d: Fourth pulley 143: Drive pulley 143a: Fastening member 144 Timing belts 144a: timing pulley 145: drive motor 145a: drive shaft 151: wire fixing member 401: light source unit 402a, 402b, 402c, 402d, 402e: a reflecting mirror 403: imaging lens unit 405: image sensor 406: driving circuit board

Japanese Patent No. 3640232 Japanese Patent Laid-Open No. 10-161401

Claims (16)

A scanning unit comprising at least illumination means for irradiating light on the document surface, and supported by the housing so as to be movable along the document surface;
One linear member is folded back multiple times by a plurality of pulleys in the casing to form a plurality of moving direction spanning sections that span from one end to the other end of the scanning unit in the casing. A plurality of moving direction transferring portions that move in the same direction among the direction transferring portions; and a moving means that moves the scanning unit along the document surface via the linear member. In the image reading apparatus provided,
The linear members are arranged so that the moving direction extending portion on one end side and the moving direction extending portion on the other end side are in the same direction in the arrangement direction of the extending portions of the linear member. Set up
The moving direction spanning portion on the one end side is fixed to one end in the arrangement direction of the bridging portions of the linear members of the scanning unit, and the moving direction spanning portion on the other end side is fixed to the linear shape of the scanning unit. An image reading apparatus fixed to the other end in the arrangement direction of the span of the member. The image reading apparatus according to claim 1,
An image reading apparatus, wherein the linear member is disposed so that the linear member intersects at one place in a housing. The image reading apparatus according to claim 2,
The linear member includes a first pulley disposed on one end side of the casing in the moving direction of the scanning unit and one end side of the moving direction spanning portion and a moving direction of the scanning unit on the casing. The first moving direction spanning portion spanned between the other end side and a second pulley disposed on one end side of the moving direction spanning portion in the arrangement direction, and the scanning unit of the second pulley and the casing A second moving direction spanning portion spanned between one end side in the moving direction and a third pulley disposed on the other end side in the arranging direction of the moving direction spanning portions, the third pulley, and the housing A third moving direction spanning portion spanned between the other end side in the moving direction of the scanning unit and the fourth pulley disposed on the other end side in the arranging direction of the moving direction spanning portion; The second moving direction is hung over the first pulley. A fourth movement direction hooking passing portion which intersects with only passing section,
An image reading apparatus, wherein the scanning unit is fixed to the first movement direction spanning section and the third movement direction spanning section. The image reading apparatus according to any one of claims 1 to 3,
The drive pulley for driving the linear member among the plurality of pulleys fixes a part of the linear member and winds the linear member a plurality of times. The image reading apparatus according to claim 3.
Among the plurality of pulleys, the driving pulley that drives the linear member is a part of the linear member that is fixed, and the linear member is wound a plurality of times.
An image reading apparatus, wherein the drive pulley is disposed between the second pulley and the third pulley or between the fourth pulley and the first pulley. The image reading apparatus according to claim 1,
An image reading apparatus comprising tension maintaining means for maintaining the tension of the linear member at a predetermined tension even when an inertial force of the scanning unit is applied to the linear member. The image reading apparatus according to claim 6.
The tension maintaining means includes a first end fixing means for fixing one end of the linear member to the scanning unit, and a state in which a predetermined tension is applied to the linear member by pulling the other end of the linear member by a pulling means. And an other end fixing means for fixing the other end of the linear member to the scanning unit. The image reading apparatus according to claim 7.
The pulling means is a tension spring, one end is fixed to the scanning unit, and the other end is fixed to the other end fixing means,
The other end fixing means fixes the other end of the linear member and the other end of the tension spring, and is a tension adjustment member that is movable within a predetermined range in the biasing direction of the tension spring with respect to the scanning unit. And a fixing member that fixes the tension adjusting member to the scanning unit in a state in which a predetermined tension is applied to the linear member. The image reading apparatus according to claim 1,
Linear member fixing means for fixing the linear member to the scanning unit;
An image reading apparatus characterized in that a fixing portion of the linear member fixing means with the scanning unit is a main scanning plane projection position of the center of gravity of the scanning unit. The image reading apparatus according to claim 1,
An image reading apparatus comprising: a rotation restricting means for restricting the rotation of the linear member fixing means for fixing the linear member to the scanning unit around the main scanning direction. The image reading apparatus according to claim 1,
A tension maintaining means for maintaining the tension of the linear member at a predetermined tension even when the inertial force of the scanning unit is applied to the linear member;
An image reading apparatus characterized in that the tension maintaining means is provided with a linear member fixing means for fixing the linear member to the scanning unit. The image reading apparatus according to claim 1,
A tension maintaining means for maintaining the tension of the linear member at a predetermined tension even when the inertial force of the scanning unit is applied to the linear member;
An image reading apparatus comprising: a tension maintaining unit; and a linear member fixing unit that fixes the linear member to the scanning unit. The image reading apparatus according to claim 1,
The scanning unit includes an image pickup device. The image reading apparatus according to claim 1,
An image reading device, wherein the scanning unit is urged toward a guide member that guides travel of the scanning unit by tension of the linear member by fixing the scanning unit and the linear member. apparatus. An image forming apparatus comprising: an image reading device that reads an image of a document; and an image forming unit that forms an image based on a result of reading by the image reading device.
An image forming apparatus using the image reading apparatus according to claim 1 as the image reading apparatus. The image forming apparatus according to claim 15.
The image forming unit discharges recording paper on the upper surface from a paper discharge unit provided so as to protrude from one end of the scanning unit in the moving direction on the upper surface.
The image reading device is supported by a support provided on the paper discharge unit, and has a paper discharge space between the upper surface of the image forming unit and the image reading device,
An image forming apparatus comprising: a drive pulley that drives the linear member among the plurality of pulleys so as to be positioned above the paper discharge unit of the image forming unit.

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