JP6761072B2 - Image reader and image forming device - Google Patents

Description

The present invention relates to an image reader and an image forming apparatus, and particularly includes an image reading apparatus and an image forming apparatus for reciprocating a scanning unit for reading an image on a document placed on a platen. Regarding the device.

Patent Document 1 discloses an example of a conventional image reading device including a driving device of this type. The drive device of Patent Document 1 applies tension to a transmission timing belt (traction member) for transmitting the driving force of the drive pulley to a reading unit (scanning unit) for reading image information, and the transmission timing belt. It is equipped with a tension pulley (driven pulley) for the purpose. The tension pulley is rotatably supported by a tension pulley base (pulley holder) fixed to the guide rail.

Japanese Unexamined Patent Publication No. 11-215320 [H04N 1/04]

When assembling the drive device of Patent Document 1, the driven pulley is fixed to the pulley holder with screws or the like, and the pulley holder is fastened to the guide rail with screws or the like while applying tension to the traction member. Assembly work) was troublesome. Further, when replacing the driven pulley, it is also necessary to remove and tighten the screw, and it takes time and effort to replace the driven pulley.

Therefore, a main object of the present invention is to provide a novel image reader and image forming apparatus.

Another object of the present invention is to provide an image reading device and an image forming device capable of easily attaching and detaching a driven pulley to and from a pulley holder.

The invention of claim 1 is an image reading device including a document mounting table and a scanning unit for reading an image on a document mounted on the document mounting table, and a traction member and a traction member for pulling the scanning unit. The drive pulley that transmits the driving force to the traction member, the driven pulley around which the traction member is wound while tension is applied to the traction member, and the pulley shaft that rotatably holds the driven pulley, and the driven pulley are engaged from the pulley shaft side. It is provided with a pulley holder having a locking claw that can be stopped and can be unlocked from the driven pulley by tilting toward the shaft center side of the pulley shaft due to elastic deformation, and the pulley shaft is a driven pulley. There has a groove-shaped cutout portion formed by cutting a part of the outer peripheral surface of the pulley shaft to slide, the locking claw is provided in the notch, an image reading apparatus.

According to the invention of claim 1, the pulley holder is provided with a locking claw that can lock the driven pulley from the pulley shaft side and can release the locking with the driven pulley by elastic deformation. By simply fitting the driven pulley on the pulley shaft, the driven pulley can be held rotatably and in a state of being prevented from coming off with respect to the pulley holder. Further, the driven pulley can be removed from the pulley holder simply by pulling out the driven pulley from the pulley shaft while tilting the locking claw toward the center of the shaft. That is, the driven pulley can be easily attached to and detached from the pulley holder.

Further, since a screw, a washer, or the like is not required when attaching the driven pulley to the pulley shaft, the number of parts can be reduced, and the manufacturing cost can be reduced.

The invention of claim 2 is dependent on the invention of claim 1, and is an image reading device in which a reinforcing portion is integrally formed with the locking claw at the lower end portion of the locking claw.

The invention of claim 3 is dependent on the invention of claim 1 or 2 , and the shaft center of the drive pulley, the shaft center of the driven pulley, and the center of the holding member for mounting the pulley holder in the image reading device are in a straight line. It is an image reading device arranged on a line.

The invention of claim 4 is subordinate to any of the inventions of claims 1 to 3 , and the pulley holder is an image reading device having two locking claws.

According to the invention of claim 4 , since the pulley holder has two locking claws, the driven pulley can be more reliably prevented from coming off.

The invention of claim 5 is dependent on the invention of claim 3, retained member, than the pulley shaft is arranged in the tension acting direction side from the pulling member to the driven pulley, an image reading apparatus.

According to the invention of claim 5 , since the holding member is arranged on the tension acting direction side by the traction member with respect to the pulley shaft, the pulley shaft and the driven pulley can be arranged near the side plate of the housing of the image reading device. The image reader can be miniaturized in the sub-scanning direction.

The invention of claim 6 is dependent on the invention of claim 3, the pulley holder has a long hole hold member is inserted, extends in tension acting direction of the driven pulley from the traction member from the axial center of the pulley shaft It is an image reading device that is mounted in the image reading device so as to be movable in the linear direction.

The invention of claim 7 is subordinate to any of the inventions of claims 1 to 6 , and the pulley holder is integrally formed with the pulley holder, and the tension acts in the direction of tension from the center of the pulley shaft to the driven pulley. An image reading device further comprising a first protrusion that projects upward at a position on the extending line.

The invention of claim 8 is subordinate to the invention of any one of claims 1 to 7 , and includes a first guide portion that guides the movement of the pulley holder, and the side surface of the pulley holder is slidable with respect to the first guide portion. This is an image reading device in which a second protrusion that comes into contact with the image is formed.

The invention of claim 9 is subordinate to any of the inventions of claims 1 to 8 , and includes a second guide portion that guides the reciprocating movement of the scanning unit, and the traction member is more of an image reading device than the second guide portion . Arranged on the front side, the locking claw is located in the circumferential direction of the driven pulley on the side of the tension acting direction from the traction member to the driven pulley with respect to the axial center of the pulley shaft, and is the shaft of the pulley shaft. It is an image reading device arranged at a position on the front side of the image reading device with respect to the center.

The invention of claim 10 is an image forming apparatus including the image reading apparatus according to any one of claims 1 to 9 .

According to the invention of claim 10, as in the invention of claim 1, the driven pulley can be easily attached to and detached from the pulley holder, and the number of parts can be reduced.

The invention of claim 11 is an image forming apparatus according to the invention of claim 10 , which is arranged on the front side of the image reading device and includes an operation unit for receiving an input operation by a user.

According to the present invention, the pulley holder is provided with a locking claw that can lock the driven pulley from the pulley shaft side and can release the locking with the driven pulley by elastic deformation. Therefore, the driven pulley can be held in a rotatably and prevented state with respect to the pulley holder simply by fitting the driven pulley on the pulley shaft. Further, the driven pulley can be removed from the pulley holder simply by pulling out the driven pulley from the pulley shaft while tilting the locking claw toward the center of the shaft. That is, the driven pulley can be easily attached to and detached from the pulley holder.

The above-mentioned object, other object, feature and advantage of the present invention will become more apparent from the detailed description of the examples described below with reference to the drawings.

It is a schematic diagram which shows the appearance of the image forming apparatus provided with the image reading apparatus which is 1st Example of this invention. It is a top view which shows the internal structure of the image reading apparatus of FIG. FIG. 5 is a cross-sectional view schematically showing a vertical cross section of the image reader of FIG. 1. FIG. 5 is a partially enlarged perspective view showing a partial configuration of a drive device included in the image reading device of FIG. 1. FIG. 4 is an illustrated view showing a pulley holder included in the drive device of FIG. 4, (a) is a perspective view of the pulley holder, (b) is a plan view of the pulley holder, and (c) is a side view of the pulley holder as viewed from the front side. Is. FIG. 5 is an enlarged schematic view showing a tip portion of a locking claw included in the pulley holder of FIG. It is explanatory drawing for demonstrating the arrangement position of the locking claw on a pulley shaft. It is a schematic diagram which shows the pulley holder provided in the drive device of the image reading apparatus which is 2nd Embodiment of this invention, (a) is the perspective view of the pulley holder, (b) is the plan view of the pulley holder, (c). Is a side view of the pulley holder as viewed from the rear side. It is a schematic diagram which shows the pulley holder provided in the drive device of the image reading apparatus which is 3rd Embodiment of this invention, (a) is the perspective view of the pulley holder, (b) is the plan view of the pulley holder, (c). Is a side view of the pulley holder as viewed from the front side.

[First Example]
Hereinafter, the image reading device 100 according to the first embodiment of the present invention will be described with reference to the drawings as appropriate. FIG. 1 is an illustrated diagram showing the appearance of an image forming apparatus 102 including an image reading apparatus 100. 2 is a plan view showing the internal configuration of the image reading device 100, and FIG. 3 is a cross-sectional view schematically showing a vertical cross section of the image reading device 100.

With reference to FIGS. 1 to 3, the image reading device 100 includes a driving device 10 for reciprocating the scanning unit 32 in the sub-scanning direction, and forms an image of a copying machine, a facsimile, a printer, a multifunction device thereof, or the like. Used in device 102. In this embodiment, the image forming apparatus 102 is a multifunction device (MFP: Multifunction Peripheral) having a copying function, a printer function, a scanner function, a facsimile function, and the like.

First, the basic configuration of the image forming apparatus 102 will be schematically described. As shown in FIGS. 1 to 3, the image forming apparatus 102 includes the apparatus main body 12 and the image reading apparatus 100 arranged above the apparatus main body 12, and the image data read by the image reading apparatus 100 or transmitted from an external computer. Based on the image data, a multicolored or monochromatic image is formed on a predetermined paper (recording paper).

A control unit 14 for controlling the operation of each part of the image forming apparatus 102 is provided at a predetermined position in the apparatus main body 12. The control unit 14 includes a CPU, a memory, and the like, and transmits control signals to each part of the image forming apparatus 102 in response to an input operation to the operation unit 16 such as a touch panel and an operation button, and variously transmits the control signal to the image forming apparatus 102. To execute the operation of.

Further, the apparatus main body 12 is equipped with an image forming unit 18 including an exposure unit, a photoconductor drum, a charger, a developing apparatus, a fixing roller, and the like. The image forming unit 18 forms an image on the recording paper conveyed from the paper feed cassette 20 or the like, and discharges the image-formed recording paper to the discharge tray 22.

The image reading device 100 includes a housing 24 having a rectangular flat plate-shaped bottom plate 24a and a side wall 24b rising from a peripheral edge thereof. A document mounting table 26 made of a transparent material is provided on the top surface of the housing 24. Further, a document holding cover 28 is movably attached above the document mounting table 26 via a hinge or the like. The document holding cover 28 is provided with an ADF (automatic document feeder) 30 that automatically feeds the documents placed on the document tray one by one with respect to the image reading position. Further, on the front side of the housing 24, an operation unit 16 such as a touch panel and operation buttons that accept input operations by the user is provided.

Further, in the housing 24, CIS scanning is performed below the CIS (Contact Image Sensor) scanning body 32, the guide shaft 34, and the document mounting table 26 for reading the image on the document mounted on the document mounting table 26. A drive device 10 or the like for reciprocating the body 32 is provided. As will be described later, when reading an image on a document placed on the document mounting table 26, the CIS scanning body 32 reciprocates below the document mounting table 26 to read the image on the document. The image data is acquired. On the other hand, when reading an image on a document placed on a document tray, the CIS scanning body 32 stands by below a predetermined image reading position, and the document conveyed by the ADF 30 is placed at the image reading position (CIS scanning body). When passing through (32), the image on the document is read and the image data is acquired.

The CIS scanning body (scanning unit) 32 is a so-called close contact type image sensor, and includes a light source, a rod lens array, a plurality of imaging elements (photoelectric conversion elements), and the like. The light source is, for example, an LED array in which a plurality of LEDs are arranged, and illuminates the surface of the document. The rod lens array collects the reflected light from the document on a plurality of image pickup elements. The plurality of image pickup devices read the pixel information imaged by the rod lens array. A scanning unit that uses a CCD (Charge Coupled Device) sensor can also be used instead of the CIS scanning body 32.

The guide shaft 34 guides the reciprocating movement of the CIS scanning body 32, and extends on the bottom plate 24a of the housing 24 in the moving direction (sub-scanning direction) of the CIS scanning body 32. The CIS scanning body 32 is movably supported by the guide shaft 34, and moves back and forth below the document mounting table 26 by obtaining a driving force from the driving device 10.

Subsequently, the configuration of the drive device 10 will be specifically described with reference to FIGS. 2 to 6. As shown in FIGS. 2 and 3, the drive device 10 includes a drive pulley 36, a driven pulley 38, a traction member 40, and the like.

The drive pulley 36 is provided near one end of the guide shaft 34, and the driven pulley 38 is provided near the other end of the guide shaft 34. An endless band-shaped towing member 40 is wound (wound) around the driving pulley 36 and the driven pulley 38, and the CIS scanning body 32 is connected to the towing member 40. The drive pulley 36 is rotated by a motor that is a drive source, and the driving force thereof is transmitted to the traction member 40. The towing member 40 is composed of a timing belt, a wire, a chain, or the like, and pulls the CIS scanning body 32 by rotating around with the rotation of the drive pulley 36. As a result, the CIS scanning body 32 is reciprocated along the guide shaft 34. Further, the driven pulley 38 applies a predetermined tension to the towing member 40, and rotates with the circumferential movement of the towing member 40.

Hereinafter, the support structure of the driven pulley 38 will be described. FIG. 4 is a partially enlarged perspective view showing the configuration of a part (peripheral portion of the driven pulley 38) of the drive device 10 included in the image reading device 100. 5A and 5B are schematic views showing a pulley holder 42 included in the drive device 10, where FIG. 5A is a perspective view of the pulley holder 42, FIG. 5B is a plan view of the pulley holder 42, and FIG. 5C is a plan view of the pulley holder 42. It is a side view seen from the front side. FIG. 6 is a partial cross-sectional view showing an enlarged tip portion of the locking claw 56 included in the pulley holder 42. FIG. 7 is an illustrated diagram for explaining the arrangement position of the locking claw 56 on the pulley shaft 44.

As shown in FIG. 4, the driven pulley 38 is attached to the bottom plate 24a of the housing 24 by using the pulley holder 42. Specifically, the pulley holder 42 is attached to the bottom plate 24a by a holding member 46 such as a washer and a step screw in a state where the driven pulley 38 is rotatably supported by a pulley shaft 44 formed on the pulley holder 42. The pulley holder 42 can be slidable in the sub-scanning direction by being fitted into a guide portion 48 projecting from the bottom plate 24a in a substantially U-shape. Further, a tension applying member 50, which is an elastic member such as a spring, is provided at the end of the pulley holder 42 on the drive pulley 36 side. The pulley holder 42 is pressed and urged by the tension applying member 50 in a direction in which tension is applied to the traction member 40, that is, in a direction in which the driven pulley 38 is separated from the drive pulley 36 along the guide shaft 34.

Subsequently, a specific configuration of the pulley holder 42 will be described. As shown in FIG. 5, the pulley holder 42 includes a holder body 52, a spring mounting portion 54, a pulley shaft 44 having a locking claw 56, and the like, and these are integrally molded with a synthetic resin or the like.

The holder body 52 is formed in a rectangular flat plate shape, and a short columnar spring mounting portion 54 is formed on the end surface of the drive pulley 36 side (that is, the direction side in which the driven pulley 38 is pulled by the traction member 40). .. In this first embodiment, the direction side in which the driven pulley 38 is pulled by the towing member 40 is defined as the tension acting direction side from the towing member 40 to the driven pulley 38. The above-mentioned tension applying member 50 is attached to the spring mounting portion 54. Further, a pulley shaft 44 is formed at the end of the holder body 52 opposite to the spring mounting portion 54 so as to project upward. The specific configuration of the pulley shaft 44 will be described later.

Further, an elongated hole 60 is formed in the central portion of the holder body 52 so that the position of the pulley holder 42 can be adjusted in the sub-scanning direction. Then, the holding member 46 is fixed to the bottom plate 24a through the elongated hole 60. That is, the holding member 46 for mounting the pulley holder 42 in the housing 24 of the image reading device 100 is on the drive pulley 36 side (tension action from the traction member 40 to the driven pulley 38) with respect to the pulley shaft 44 that supports the driven pulley 38. It is placed on the directional side). Specifically, in this embodiment, the holding member 46 is arranged on a line L extending from the shaft center C of the pulley shaft 44 in the tension acting direction by the traction member 40 (the shaft center C and the line L are shown in FIG. 7). To. By arranging the holding member 46 closer to the tension acting direction of the traction member 40 than the pulley shaft 44 in this way, the pulley shaft 44 and the driven pulley 38 can be arranged in the vicinity of the side plate 24b of the housing 24, so that the image reading device can be used. It is possible to reduce the size of 100 in the sub-scanning direction.

Further, protrusions 62 having a substantially semicircular cross section are formed on both side surfaces of the holder body 52 (both end surfaces in a direction orthogonal to the tension acting direction of the traction member 40). When the tip of the protrusion 62 comes into contact with the guide portion 48 described above, the contact area between the holder body 52 and the guide portion 48 is reduced, and the frictional force between the holder body 52 and the guide portion 48 is reduced. .. Therefore, the pulley holder 42 can smoothly slide in the guide portion 48.

Next, a specific configuration of the pulley shaft 44 will be described. As shown in FIG. 5, the pulley shaft 44 is a support shaft that rotatably supports the driven pulley 38, and includes a shaft body 64 formed in a substantially cylindrical shape. The outer diameter of the shaft body 64 is set to be substantially the same as the inner diameter of the driven pulley 38, and the driven pulley 38 rotates so that the inner surface of the driven pulley 38 slides on the outer surface of the shaft body 64. .. Further, the shaft body 64 is partially cut out in the circumferential direction, and a locking claw 56 for locking the upper end portion of the driven pulley 38 is formed in the cutout portion. In this first embodiment, one locking claw 56 is arranged on the tension acting direction side from the traction member 40 to the driven pulley 38 in the circumferential position on the pulley shaft 44. Specifically, the locking claw 56 is on a line extending through the axis center C of the pulley shaft 44 in the direction of tension acting by the traction member 40, and is arranged at a position closest to the drive pulley 36. That is, in this embodiment, the shaft center of the drive pulley 36, the shaft center of the driven pulley 38 (that is, the shaft center C of the pulley shaft 44), the center of the locking claw 56, and the center of the holding member 46 are aligned. It is arranged on a line (see FIG. 2).

The locking claw 56 includes a tilting piece 56a that protrudes outward from the inner side surface of the shaft body 64 and stands up upward, and a locking piece 56b that extends outward from the tip end portion of the tilting piece 56a. By locking the upper end portion of the driven pulley 38 with the locking piece 56b, the driven pulley 38 rotatably held by the pulley shaft 44 is prevented from coming off (see FIGS. 4 and 6). Further, the width dimension of the tilting piece 56a in the radial direction of the pulley shaft 44 is formed to be smaller than the width dimension in the circumferential direction of the pulley shaft 44. That is, the tilting piece 56a (locking claw 56) is difficult to tilt with respect to the circumferential direction side of the pulley shaft 44, but is easily tilted toward the axis center C side of the pulley shaft 44. The locking claw 56 can be released from being locked with the driven pulley 38 by tilting toward the axis center C side of the pulley shaft 44 due to elastic deformation. Further, a flat plate-shaped reinforcing portion 66 is integrally formed at the lower end portion of the locking claw 56.

Further, as can be clearly seen from FIG. 6, a linear inclined surface 56c having a downward slope toward the outside is formed at the upper end portion (upper surface of the tip portion) on the outer side of the locking claw 56. By forming the inclined surface 56c, when the driven pulley 38 is attached to the pulley shaft 44, the lower end of the pulley shaft 44 comes into contact with the inclined surface 56c, so that the locking claw 56 naturally becomes the shaft of the pulley shaft 44. It will tilt toward the center C side. Therefore, the driven pulley 38 can be easily attached.

Further, the upper end surface of the locking claw 56 is a flat surface 56d extending in a direction orthogonal to the axis center C of the pulley shaft 44. By making the upper end surface of the locking claw 56 a flat surface 56d, the height dimension of the locking claw 56 can be kept low, and the pulley holder 42 can be made thinner.

Further, an arc-shaped (R-shaped) inclined surface 56e having a downward slope toward the axis center C of the pulley shaft 44 is formed at the upper end portion of the locking claw 56 on the axis center C side. By forming the inclined surface 56e, the locking claw 56 can be greatly tilted toward the axis center C side of the pulley shaft 44 when the driven pulley 38 is attached or detached. That is, since the locking claw 56 tilts with its lower end as a fulcrum, the upper end thereof is greatly tilted, but an inclined surface 56e is formed at the upper end of the locking claw 56 on the axial center C side (that is,). By eliminating the corner portion), it becomes difficult to interfere with the shaft body 64 when the locking claw 56 is tilted. If the locking claw 56 can be tilted significantly toward the axis center C side of the pulley shaft 44, the amount of the locking claw 56 caught on the driven pulley 38 (locking length) is increased accordingly. Since this is possible, the driven pulley 38 can be more reliably prevented from coming off by the locking claw 56. The effect of forming such an inclined surface 56e is particularly remarkable when a plurality of locking claws 56 are formed on the pulley shaft 44 as in the third embodiment described later. This is because it is possible to prevent each of the locking claws 56 from tilting and interfering with each other.

In this first embodiment, the inclined surface 56c is a linear inclined surface, and the inclined surface 56e is an arc-shaped inclined surface. However, the inclined surface 56c may be an arcuate inclined surface, or the inclined surface 56e may be a linear inclined surface.

Here, the position of the locking claw 56 in the circumferential direction of the pulley shaft 44 is on the direction side (tension action direction side (see FIG. 7)) in which the driven pulley 38 is pulled by the traction member 40, rather than the position farthest from the drive pulley 36. ))). This is because if the locking claw 56 is arranged on the opposite side of the tension acting direction from the traction member 40 to the driven pulley 38, the locking claw 56 may come off due to the load from the traction member 40. is there. That is, when tension is applied to the towing member 40, the driven pulley 38 is pulled by the towing member 40. Since the locking claw 56 is formed so as to be tiltable (to easily bend) toward the axis center C side of the pulley shaft 44, the locking claw 56 is formed on the side opposite to the tension acting direction from the traction member 40 to the driven pulley 38. When the 56 is arranged, the locking claw 56 bends toward the axis center C side of the pulley shaft 44 due to the load from the traction member 40. When this deflection becomes large, the driven pulley 38 rides on the tip of the locking claw 56, and the driven pulley 38 is unlocked by the locking claw 56. As a result, the driven pulley 38 rotates in a state where the tip of the locking claw 56 and the driven pulley 38 are in contact with each other, and the rotational load of the driven pulley 38 becomes large. As a result, the pulley shaft 44 and the driven pulley 38 may be damaged. Therefore, as described above, it is preferable that the locking claw 56 is arranged on the tension acting direction side from the towing member 40 to the driven pulley 38 rather than the position farthest from the driving pulley 36.

As shown in FIG. 7, in the present invention, the tension acting direction side indicating the arrangement position of the locking claw 56 is the direction in which the driven pulley 38 applies tension to the traction member 40 (tension by the driven pulley 38). It can also be said to be a range other than the granting direction). Among them, preferably, the locking claw 56 is within a range R of 270 ° with the line L extending in the tension acting direction from the axis center C of the pulley shaft 44 as the center line (center) at the position in the circumferential direction of the pulley shaft 44. That is, two lines that are on the tension acting direction side (drive pulley 36 side) and have an angle of 135 ° clockwise and counterclockwise with respect to the line L extending from the axis center C in the tension acting direction. It is placed within a range R of 270 ° between the lines. More preferably, the locking claw 56 is on the tension acting direction side (drive pulley 36 side), and the line L extending from the axis center C of the pulley shaft 44 in the tension acting direction is the center line of the pulley shaft 44. It is arranged at a position (range) up to a line orthogonal to the line extending in the tension acting direction through the axis center C. Particularly preferably, the locking claw 56 is at a position where it is most difficult to receive the load from the traction member 40, and specifically, as shown in FIG. 5, the tension action by the traction member 40 from the axis center C of the pulley shaft 44. It is arranged on the line L extending in the direction, that is, at the position closest to the drive pulley 36.

In the pulley holder 42 having the pulley shaft 44 having such a configuration, the driven pulley 38 can be attached to the pulley shaft 44 simply by pushing the driven pulley 38 from above and fitting it into the pulley shaft 44. When the driven pulley 38 is attached to the pulley shaft 44 (when in use), the upper end of the driven pulley 38 is locked by the locking piece 56b of the locking claw 56, so that the driven pulley 38 is securely prevented from coming off. Will be done. Further, at the time of replacement or maintenance of the towing member 40, the driven pulley 38, etc., the driven pulley 38 can be pulled out from the pulley shaft 44 by simply pulling out the driven pulley 38 while tilting the locking claw 56 toward the shaft center C side by elastic deformation. Can be removed.

According to the first embodiment, the upper end portion of the driven pulley 38 can be locked with respect to the pulley shaft 44 included in the pulley holder 42, and the driven pulley 38 is tilted toward the shaft center C side by elastic deformation. A locking claw 56 capable of releasing the locking with the pulley 38 is provided. Therefore, the driven pulley 38 can be held in a state in which the driven pulley 38 can be rotated and is prevented from coming off with respect to the pulley holder 42 (pulley shaft 44) simply by fitting the driven pulley 38 into the pulley shaft 44. That is, the work of attaching the driven pulley 38 to the pulley holder 42 becomes easy. Further, when removing the driven pulley 38, it is only necessary to pull out the driven pulley 38 from the pulley shaft 44 while tilting the locking claw 56 toward the shaft center C side, so that the removal work of the driven pulley 38 becomes easy. That is, according to the first embodiment, the driven pulley 38 can be easily attached to and detached from the pulley holder 42.

Further, according to the first embodiment, since a mounting member such as a screw or a washer is not required when mounting the driven pulley 38 of the pulley shaft 44, the number of parts can be reduced, and the manufacturing cost can be reduced.

Further, according to the first embodiment, since the locking claw 56 is arranged on the tension acting direction side from the traction member 40 to the driven pulley 38 from the position farthest from the drive pulley 36, tension is applied to the traction member 40. Even in this state, the locking claw 56 does not easily come off from the upper end of the driven pulley 38. In particular, in this first embodiment, since the locking claw 56 is arranged at the position closest to the drive pulley 36, which is the position where the load from the traction member 40 is most difficult to receive, the pulley shaft 44 is driven more stably. The pulley 38 can be held.

[Second Example]
Next, the image reading device 100, which is the second embodiment of the present invention, will be described with reference to FIG. In this second embodiment, the arrangement position of the locking claw 56 is different from that in the first embodiment described above. Since the configurations of the other parts are the same, the parts common to the above-described first embodiment are given the same reference numbers, and duplicate explanations will be omitted or simplified. Then, in the following, only the configuration of the pulley holder 42 included in the drive device 10 of the image reading device 100 of the second embodiment will be described. 8A and 8B are schematic views showing a pulley holder 42 included in the drive device 10 of the image reading device 100, FIG. 8A is a perspective view of the pulley holder 42, FIG. 8B is a plan view of the pulley holder 42, and FIG. Is a side view of the pulley holder 42 as viewed from the rear side.

As shown in FIG. 8, the pulley holder 42 includes a holder body 52, a spring mounting portion 54, a pulley shaft 44 having a locking claw 56, and the like, and these are integrally molded with a synthetic resin or the like. The locking claw 56 includes a tilting piece 56a and a locking piece 56b, and the width dimension of the tilting piece 56a in the radial direction of the pulley shaft 44 is formed to be smaller than the width dimension of the pulley shaft 44 in the circumferential direction.

Then, in the second embodiment, the locking claw 56 is arranged on a line orthogonal to the line extending in the tension acting direction through the axis center C of the pulley shaft 44 in the circumferential position on the pulley shaft 44. When the locking claw 56 is arranged at such a position, the load from the traction member 40 is mainly applied to the shaft body 64 when tension is applied to the traction member 40, so that the load applied to the locking claw 56 becomes small. .. Further, since the locking claw 56 has a shape that does not easily tilt with respect to the circumferential direction side of the pulley shaft 44, even if a load is received from the traction member 40, it does not easily bend in the tension acting direction. Therefore, the locking claw 56 is hard to come off from the upper end portion of the driven pulley 38, and the pulley shaft 44 can stably hold the driven pulley 38.

According to the second embodiment, since the pulley shaft 44 has the locking claw 56, the driven pulley 38 can be easily attached to and detached from the pulley holder 42 as in the first embodiment described above.

Further, according to the second embodiment, since the locking claw 56 is arranged on the tension acting direction side from the traction member 40 to the driven pulley 38 from the position farthest from the drive pulley 36, tension is applied to the traction member 40. Even in this state, the locking claw 56 does not easily come off from the upper end of the driven pulley 38.

In the second embodiment, the locking claw 56 is arranged on the back side in FIG. 8, but of course, the locking claw 56 can be arranged on the opposite side, that is, the front side.

[Third Example]
Subsequently, the image reading device 100, which is the third embodiment of the present invention, will be described with reference to FIG. This third embodiment is different from the first and second embodiments described above in that two locking claws 56 are formed on the pulley shaft 44. Since the configurations of the other parts are the same, the parts common to the above-mentioned first and second embodiments are given the same reference numbers, and the duplicated description will be omitted or simplified. Then, in the following, only the configuration of the pulley holder 42 included in the drive device 10 of the image reading device 100 of the third embodiment will be described. 9A and 9B are schematic views showing a pulley holder 42 included in the drive device 10 of the image reading device 100, FIG. 9A is a perspective view of the pulley holder 42, FIG. 9B is a plan view of the pulley holder 42, and FIG. Is a side view of the pulley holder 42 as viewed from the back surface side.

As shown in FIG. 9, the pulley holder 42 includes a holder body 52, a spring mounting portion 54, a pulley shaft 44 having a locking claw 56, and the like, and these are integrally molded with a synthetic resin or the like.

The pulley shaft 44 includes a shaft body 64 that is formed in a substantially cylindrical shape. The shaft body 64 is cut out at two points on a line orthogonal to the line extending in the tension acting direction through the shaft center C of the pulley shaft 44, and locking claws 56 are formed in each of the cutout portions. That is, in this third embodiment, the pulley shaft 44 has two locking claws 56, and the two locking claws 56 are centered on a line extending in the tension acting direction through the axis center C of the pulley shaft 44. Arranged line-symmetrically as a line.

The locking claw 56 includes a rectangular plate-shaped tilting piece 56a projecting upward from the holder body 52, and a locking piece 56b extending outward from the tip of the tilting piece 56a. The width dimension of the tilting piece 56a in the radial direction of the pulley shaft 44 is formed to be smaller than the width dimension of the pulley shaft 44 in the circumferential direction. Further, an arcuate inclined surface 56e having a downward slope toward the axis center C of the pulley shaft 44 is formed at the upper end portion of the locking claw 56 on the axis center C side (see FIG. 6). When two locking claws 56 are formed, each of the two locking claws 56 tilts toward the axis center C side when the driven pulley 38 is attached or detached, but the axis center C side of the locking claw 56 By forming the inclined surface 56e on the upper end portion of the above, the locking claws 56 are less likely to interfere with each other.

According to the third embodiment, since the pulley shaft 44 has the locking claw 56, the driven pulley 38 can be easily attached to and detached from the pulley holder 42 as in the first embodiment described above.

Further, according to the third embodiment, since the locking claw 56 is arranged on the tension acting direction side from the traction member 40 to the driven pulley 38 from the position farthest from the drive pulley 36, tension is applied to the traction member 40. Even in this state, the locking claw 56 does not easily come off from the upper end of the driven pulley 38.

Further, according to the third embodiment, since the pulley shaft 44 has two locking claws 56, the driven pulley 38 can be more reliably prevented from coming off. Further, at this time, since the two locking claws 56 are arranged symmetrically with the line extending in the tension acting direction passing through the axis center C of the pulley shaft 44 as the center line, the pulley shaft 44 balances the driven pulley 38. Can be rotated well.

The specific shape of the locking claw 56 is not limited to the shape shown in the first to third embodiments, and the upper end portion of the driven pulley 38 can be locked and elastically deformed. An appropriate shape can be adopted as long as the shape can be released from the locking with the driven pulley 38 by tilting toward the axis center C side.

Further, in each of the above-mentioned first to third embodiments, the driving device 10 is provided to the image forming device (multifunction device) 102 in which the image reading device 100 and the device main body 12 including the image forming unit 18 are integrated. I tried to apply it, but it is not limited to this. For example, the image reading device 100 including the driving device 10 may be an individual product. That is, the drive device 10 may be applied to the image reading device 100 having only the scanner function. In this case, the image reading device 100 is connected to a network, for example, and transmits the read image to a personal computer, another image forming device, or the like.

The specific numerical values such as dimensions and angles mentioned above are merely examples, and can be appropriately changed as necessary, such as product specifications.

10 ... Drive device 12 ... Device main body of image forming device 18 ... Image forming unit 24 ... Image reading device housing 26 ... Document mounting table 32 ... Scanning unit (CIS scanning body)
34 ... Guide shaft 36 ... Drive pulley 38 ... Driven pulley 40 ... Tow member 42 ... Pulley holder 44 ... Pulley shaft 46 ... Holding member 50 ... Tension applying member 56 ... Locking claw 56a ... Tilt piece 56b ... Locking piece 56c ... Inclined surface 56d ... Flat surface 56e ... Inclined surface 100 ... Image reader 102 ... Image forming device (multifunction device)

Claims (11)

An image reading device including a document mounting table and a scanning unit for reading an image on a document placed on the document mounting table.
A traction member that pulls the scanning unit,
A drive pulley that transmits driving force to the traction member,
A driven pulley around which the traction member is wound in a state where tension is applied to the traction member, a pulley shaft that rotatably holds the driven pulley, and the driven pulley can be locked from the pulley shaft side. A pulley holder having a locking claw that can be released from the driven pulley by tilting toward the axis center side of the pulley shaft by elastic deformation is provided.
The pulley shaft has a groove-shaped notch formed by cutting out a part of the outer peripheral surface of the pulley shaft on which the driven pulley slides.
The locking claw is kicked set to the cutout portion, the image reading apparatus. The engaging the lower end of the claw, the reinforcing portion is integrally formed on the locking pawl, the image reading apparatus according to claim 1. The image according to claim 1 or 2 , wherein the shaft center of the drive pulley, the shaft center of the driven pulley, and the center of the holding member for mounting the pulley holder in the image reader are arranged in a straight line. Reader. The image reading device according to any one of claims 1 to 3 , wherein the pulley holder has two locking claws. Before Kiho support member, it said than pulley shaft is arranged in the tension acting direction side to the driven pulley from the traction member, the image reading apparatus according to claim 3, wherein. The pulley holder is pre Kiho support member has a long hole which is inserted, movably said image reading apparatus to the line direction extending in tension acting direction from the axial center of the pulley shaft to the driven pulley from the traction member The image reading device according to claim 3 , which is mounted inside. The pulley holder is formed integrally with the pulley holder, and further has a first protrusion that projects upward at a position on a line extending from the axial center of the pulley shaft in the direction of tension acting from the traction member to the driven pulley. , The image reading device according to any one of claims 1 to 6 . A first guide portion for guiding the movement of the pulley holder is provided.
The image reading device according to any one of claims 1 to 7 , wherein a second protrusion that slidably contacts the first guide is formed on the side surface of the pulley holder. A second guide unit for guiding the reciprocating movement of the scanning unit is provided.
The towing member is arranged on the front side of the image reading device with respect to the second guide portion.
The locking claw is a position in the circumferential direction of the driven pulley on the side of the tension acting direction from the traction member to the driven pulley with respect to the axial center of the pulley shaft, and the shaft of the pulley shaft. The image reading device according to any one of claims 1 to 8 , which is arranged at a position on the front side of the image reading device with respect to the center. An image forming apparatus comprising the image reading apparatus according to any one of claims 1 to 9 . The image forming apparatus according to claim 10 , further comprising an operation unit arranged on the front side of the image reading device and receiving an input operation by a user.

Images