JP2017013991A - Sheet feeding device and image formation apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet feeding device which can correctly detect the width of a sheet.SOLUTION: A sheet feeding device 4 comprises: a tray 31; a pair of side guides 32; a slide mechanism 33 which includes a pair of rack 51 and pinion 52; a sensor 55 whose output value is changed in accordance with a rotation amount of a movable unit 57; a rotation transmission member 36 which is connected so as to be integrally rotatable with the pinion at any relative position around the rotational shaft of the pinion 52 and connected to the movable unit 57; and a regulation member 63 which regulates the rotation of the rotation transmission member 36 by being engaged with the rotation transmission member 36 connected to the movable unit 57. With attachment of the pair of side guides 32 to the tray 31, and connection of the rotation transmission member 36 to the pinion 52, the rotation transmission member 36 is disengaged from the regulation member 63, rotation of the pinion 52 is transmitted to the movable unit 57 via the rotation transmission member 36, and the output value according to the rotation amount from the rotation start position of the movable unit 57 is output from the sensor 55.SELECTED DRAWING: Figure 9

Description

  The present invention relates to a paper feeding device that feeds paper to an image forming apparatus or the like, and an image forming apparatus including the paper feeding device.

  An image forming apparatus such as a multifunction peripheral or a printer is provided with a paper feeding device for feeding paper. In the paper feeding device, a tray on which paper is placed, a pair of side guides for regulating the position in the width direction of the paper placed on the tray, and a pair of side guides are synchronized in the width direction in the contact / separation direction. And a slide mechanism for sliding. As a slide mechanism, a configuration having a pair of racks provided in each of the pair of side guides and a pinion that engages with the pair of racks is common.

  Further, the paper feeding device may be configured to detect the width of the paper by aligning a pair of side guides to both side end faces in the paper width direction. An angle sensor that changes the output voltage in accordance with the rotation angle of the pinion may be used as the paper width detection device.

  In order to accurately detect the sheet width, it is necessary to accurately detect the rotation angle of the pinion. For this purpose, it is necessary to determine the relative positional relationship between the angle sensor and the pinion. For example, if the rotation shaft of the pinion and the rotation shaft of the angle sensor are provided integrally, if the position of the pinion teeth and the rack teeth are shifted at the time of initial setting and a tooth meshing failure occurs, each pinion Rotates until the teeth are fully engaged. Then, the initial setting value of the angle sensor changes and the paper width cannot be detected accurately.

  In Patent Document 1, the pair of side guides are configured to be positioned relative to each other by assembling the pinion in a state where the pair of side guides are separated and locked by the maximum distance (or the minimum distance). A paper feeder is disclosed.

JP 2007-230703 A

  However, in the paper feeding device described in Patent Document 1, the pair of side guides can be relatively positioned. However, the rack teeth and the pinion teeth provided on the pair of side guides are accurately positioned. There can be situations where they do not mesh. In such a case, there is a possibility that one of the racks is moved from the locking position or the pinion rotates and the initial setting state is not fixed. Then, in the case where the width of the sheet is detected by the sliding of the pair of side guides, it becomes impossible to accurately detect the width of the sheet.

  In view of the above circumstances, an object of the present invention is to provide a sheet feeding device capable of accurately detecting the width of a sheet and an image forming apparatus including the sheet feeding device.

  In order to achieve the above object, a sheet feeding device according to the present invention is a pair of a tray on which a sheet is placed and is supported by the tray so as to be slidable in a contact / separation direction to regulate the position in the width direction of the sheet. Each of the pair of side guides, a pair of racks provided on each of the pair of side guides and a pinion that engages with the pair of racks, a slide mechanism mounted on the tray, and a movable part, A sensor whose output value changes according to the rotation amount of the movable part, and a rotation transmission which is connected to the pinion so as to be integrally rotatable at an arbitrary relative position around the rotation axis of the pinion and connected to the movable part A member, a restricting member that engages with the rotation transmitting member connected to the movable portion and restricts rotation of the rotation transmitting member, and a rotation member that engages with the restricting member and restricts rotation. Regulatory position And a support member that is switchably supported by releasing the engagement with the restricting member to allow rotation, and the amount of rotation of the pinion transmitted to the movable part via the rotation transmitting member And a detecting device that detects a sliding distance of the pair of side guides from an output value of the sensor according to the condition, and the pinion is engaged with the rack in a state where the pair of side guides are slid to a predetermined distance. The rotation transmission member is switched from the restriction position to the permissible position by connecting the pinion to the rotation transmission member switched to the restriction position, and the rotation of the pinion via the rotation transmission member. Is transmitted to the movable part, and the pair of cycles from the predetermined distance is displaced by the displacement of the output value of the sensor according to the rotation amount from the rotation start position of the movable part. Slide distance of the guide is characterized by comprising enabling detection by the detecting device.

  By adopting such a configuration, since the rotation angle of the pinion after the slide mechanism is properly mounted can be detected by the sensor, the movement distance of the side guide can be accurately obtained.

  In the present invention, the support member may be detachably provided on the tray, and the sensor, the rotation transmission member, and the restriction member may be supported by the support member.

  By adopting such a configuration, the sensor, the rotation transmission member, and the regulating member can be handled as a unit, and the connection work between the pinion of the slide mechanism and the rotation transmission member is facilitated.

In the paper feeding device according to the present invention, the tray includes a placement surface on which the paper is placed, a concave portion that is formed along the width direction of the paper, and in which the slide mechanism and the support member are mounted. ,
A cover member that opens and closes the recess, the slide mechanism that slides the pair of side guides to the predetermined distance is supported by the cover member, the recess is closed by the cover member, and the slide The rotation transmission member may be switched to the allowable position by mounting a mechanism in the recess, connecting the rotation transmission member to the pinion, and mounting the support member in the recess.

  By adopting such a configuration, it is easy to mount the slide mechanism in which the pair of side guides are slid at a predetermined interval on the tray. Further, since the side guide and the slide mechanism are larger in size than the support member, it is easy to position the rotation transmitting member supported by the support member having a small size on the pinion.

  In the paper feeding device of the present invention, a cylindrical ring portion is erected on the back surface of the cover member, and a boss that can be fitted to the ring portion is formed on the pinion. The pinion is rotatably supported by the cover member by being fitted to the ring portion.

  By adopting such a configuration, the cover member can easily support the slide mechanism.

  In the sheet feeding device of the present invention, the support member includes a biasing member that biases the rotation transmitting member to the restriction position, and the support member is mounted on the recess and the recess is formed by the cover member. By closing, the rotation transmission member may be pressed by the cover member, separated from the restricting member against the urging force of the urging member, and switched to the allowable position.

  By adopting such a configuration, the rotation transmission member can be switched to the allowable position with a simple mechanism. Further, by using a cover member that covers the concave portion of the tray, there is no need to provide a dedicated member for switching the rotation transmitting member or add a dedicated process.

  In the paper feeding device of the present invention, a hole is formed on the rotation shaft of the pinion in one of the pinion and the rotation transmission member, and the other is fitted into the hole and elastic in the radial direction. A deformable elastic shaft is formed, and the pinion and the rotation transmission member are at an arbitrary relative position around the rotation axis of the pinion by a frictional force between the side surface of the hole and the elastic shaft. It is good also as a feature that it connects so that integral rotation is possible.

  By adopting such a configuration, it is possible to connect the pinion and the rotation transmitting member so as to be integrally rotatable at an arbitrary relative position around the rotation axis of the pinion with a simple mechanism.

  In the paper feeding device according to the present invention, the elastic shaft may have a cylindrical shape, and a bent portion that is bent in the diameter increasing direction may be formed along the circumferential direction.

  By adopting such a configuration, the frictional force between the bent portion of the elastic shaft and the side surface of the hole can be increased, and the pinion and the rotation transmitting member can be reliably rotated integrally.

  In the paper feeding device of the present invention, the pair of side guides may slide on the upper surface of the cover member.

  By adopting such a configuration, the shape of the side guide and the slide mechanism can be made compact, and the side guide can be easily attached to the tray.

  An image forming apparatus according to the present invention includes any of the above-described sheet feeding devices.

  According to the present invention, since the rotation angle of the pinion from the normal rotation start position can be measured by the sensor member, the width of the paper can be accurately detected.

1 is a front view schematically showing an internal structure of a printer according to an embodiment of the present invention. 1 is a perspective view illustrating a state where a paper feeding device according to an embodiment of the present invention is mounted on a document reading device. It is a perspective view which shows the tray of the paper feeder which concerns on one Embodiment of this invention. It is the perspective view which looked at the side guide cover of the paper feeder concerning one embodiment of the present invention from the lower part. FIG. 4 is a perspective view illustrating a side guide, a slide mechanism, and a support member of a paper feeding device according to an embodiment of the present invention. It is a perspective view which shows the detection apparatus of the paper feeder which concerns on one Embodiment of this invention. FIG. 5 is a perspective view showing a detection device supported by a support member in the paper feeding device according to the embodiment of the present invention. FIG. 4 is a side sectional view showing a rotation restricting member whose rotation is restricted by a support member in the sheet feeding device according to the embodiment of the present disclosure. FIG. 5 is a side cross-sectional view showing a rotation restricting member that is allowed to rotate by a side guide cover in the paper feeding device according to the embodiment of the present invention. FIG. 6 is a side sectional view showing a rotation transmitting member that is allowed to rotate by a side guide cover of another example in the sheet feeding device according to the embodiment of the present invention.

  Hereinafter, a sheet feeding device and an image forming apparatus according to an embodiment of the present disclosure will be described with reference to the drawings.

  With reference to FIG. 1, an overall configuration of a color printer 1 as an image forming apparatus will be described. FIG. 1 is a front view schematically showing the overall configuration of a color printer. Hereinafter, the front side of the paper surface in FIG. 1 is the front side (front side) of the color printer, and the left-right direction is based on the direction when the color printer 1 is viewed from the front.

  As shown in FIG. 1, the color printer 1 includes an image forming unit 2 and an image reading unit 3 disposed above the image forming unit 2. The image reading unit 3 includes a paper feeding device 4 that automatically conveys a sheet as a document, and a reading device 5 that reads an image of the conveyed sheet.

  In the image forming unit 2, an in-body discharge space 7 having an open front and left side is formed between the image reading unit 3 and the image reading unit 3. Below the in-body discharge space 7, a discharge tray 8 is provided on the upper surface of the image forming unit 2. The image forming unit 2 is provided with a paper feeding cassette 9 below, and above the paper feeding cassette 9 is installed between an exposure apparatus 10 constituted by a laser scanning unit (LSU) and rollers. An intermediate transfer belt 11, four image forming devices 12 arranged in parallel along the lower portion of the intermediate transfer belt 11, and a toner container 13 containing toner of four colors are provided.

  Each image forming device 12 is rotatably provided with a photosensitive drum 15 as an image carrier. Around the photosensitive drum 15, a charging device 16, a developing device 17, an intermediate transfer belt 11, and the like. A transfer roller 18 that forms a primary transfer portion, a cleaning device 19, and a charge removal device 20 are disposed in order along the rotation direction of the photosensitive drum 15.

  A transfer roller 22 is disposed on the right side of the intermediate transfer belt 11, and a secondary transfer portion 21 is formed between the intermediate transfer belt 11 and the transfer roller 22. A fixing device 23 is provided above the secondary transfer unit 21, and a paper discharge device 24 facing the paper discharge tray 8 is provided above the fixing device 23. Further, a paper transport path 25 is formed from the paper feed cassette 9 to the paper discharge device 24 through the secondary transfer unit 21 and the fixing device 23.

  An image forming operation of the printer 1 having such a configuration will be described. In each image forming device 12, after the surface of the photosensitive drum 15 is charged by the charging device 16, a static light corresponding to the image read by the image reading unit 3 by the laser light (see arrow P) from the exposure device 10. An electrostatic latent image is formed on the surface of the photosensitive drum 15. The electrostatic latent image is developed into a corresponding color toner image by the developing device 17 using toner supplied from the toner container 13. This toner image is primarily transferred onto the surface of the intermediate transfer belt 11 by the transfer roller 18. Each image forming device 12 sequentially repeats the above operation, whereby a full-color toner image is formed on the intermediate transfer belt 11. The toner and charge remaining on the photosensitive drum 15 are removed by the cleaning device 19 and the charge removal device 20.

  On the other hand, the sheet fed from the sheet feeding cassette 9 is conveyed to the secondary transfer unit 21 along the conveyance path 25 in synchronism with the above-described image forming operation, and the intermediate transfer belt in the secondary transfer unit 21. Eleven full-color toner images are secondarily transferred to the paper. The sheet on which the toner image is secondarily transferred is conveyed downstream in the conveyance path 25 and enters the fixing device 23, and the toner image is fixed on the sheet in the fixing device 23. The paper on which the toner image is fixed is discharged from the paper discharge device 24 onto the paper discharge tray 8.

  Next, the paper feeding device 4 will be described with reference to FIGS. 2 is a perspective view of a paper feeding device mounted on a document reading device, FIG. 3 is a perspective view of a tray, FIG. 4 is a perspective view of a side guide cover as viewed from below, and FIG. 5 is a pair of side guides and a slide mechanism. FIG. 6 is a perspective view of the detection device, FIG. 7 is a perspective view of the support member on which the detection device and the rotation transmission member are supported, and FIGS. 8 and 9 are rotation restrictions in the rotation restriction state and the rotation permission state. It is a sectional side view which shows a member, respectively.

  The sheet feeding device 4 includes a main body 30 that forms a sheet conveyance path, a tray 31 on which a sheet to be conveyed is placed, a pair of side guides 32 that are slidable in the contact and separation directions, and a pair of A slide mechanism 33 that slides the side guide 32 in synchronization with the contact / separation direction, a detection device 34 that detects the width of the paper, a rotation transmission mechanism 35 that is interposed between the slide mechanism 33 and the detection device 34, Is provided.

  The main body 30 is formed with a sheet conveyance path that is curved in a lateral U-shape from the upper inlet toward the lower outlet. The image of the sheet is read by the reading device 5 at a reading position in the middle of the conveyance path.

  As shown in FIG. 3, the tray 31 is a plate-like member having a rectangular planar shape and a predetermined thickness, and is supported by the main body 30 in a posture inclined obliquely downward toward the entrance of the conveyance path. Yes. A concave portion 41 extending in the paper width direction is formed on the upper surface of the tray 31 in the downstream portion in the paper conveyance direction, and the placement surface on which the paper is placed upstream of the concave portion 41 in the paper conveyance direction. 42 is formed. In the recess 41, a rectangular opening 41a is formed at the center in the paper width direction. The recess 41 is opened and closed by a cover member 43. As shown in FIG. 4, a cylindrical ring portion 44 projects from the back surface of the cover member 43 at the center in the width direction. A plurality of ribs 45 extending in the paper width direction are formed on the back surface of the cover member 43. When the cover member 43 is mounted so as to close the concave portion 41, the upper surface becomes substantially the same surface as the mounting surface 42 as shown in FIG. 2.

  As shown in FIG. 5, the pair of side guides 32 have a symmetrical shape in the paper width direction, and stand upright from the flat portion 46 on which the side edge of the paper is placed and the outer side edge of the flat portion 46. And a side wall portion 47 extending in parallel with the paper transport direction.

  As shown in FIG. 5, the slide mechanism 33 includes a pair of racks 51 provided on the flat portions 46 of the pair of side guides 32, and a pinion 52 that engages with the pair of racks 51. Each rack 51 extends from the lower surface of the flat portion 46 of the pair of side guides 32 so as to face each other, and rack teeth are formed on surfaces facing each other in the front-rear direction. Further, a groove 51 a extending in the paper width direction is formed on the upper surface of each rack 51. In the pinion 52, a boss 52a is formed in the center of the upper surface, and a through hole 53 (hole) is formed in the center of the shaft.

  As shown in FIG. 6, the detection device 34 includes a position detection sensor 55 as a sensor member, and a substrate portion 56 that supports the position detection sensor 55. The position detection sensor 55 is a rotary type potentiometer, and has a movable electrode connected to a D-cut 57 that is a movable part formed at the center. As the movable electrode moves due to the rotation of the D-cut 57, the resistance value of the variable resistor changes, and the output voltage changes. From the change in the output voltage, the rotation angle of the D-cut 57 is calculated.

  As shown in FIGS. 8 and 9, the rotation transmission mechanism 35 supports the rotation transmission member 36 that can be connected to the D-cut 57 of the position detection sensor 55, the position detection sensor 55, and is connected to the position detection sensor 55. And a support member 37 on which the rotation transmission member 36 is supported.

  The rotation transmitting member 36 includes a rotation shaft 71, a disk portion 72 formed at the upper end of the rotation shaft 71, and an elastic shaft 73 provided at the center of the upper surface of the disk portion 72. The lower end 71a of the rotating shaft 71 is formed in a D-cut shape. A pair of opposing U-shaped concave portions 75 (engaged portions) are formed at the corners of the upper surface and the peripheral portion of the disk portion 72. Further, a V-shaped notch (not shown) for alignment is formed at the peripheral edge of the disk portion 72. The elastic shaft 73 has a cylindrical shape, and a bent portion 73a bent in the diameter increasing direction is formed at the center in the height direction, and can be elastically deformed in the diameter increasing direction.

  As shown in FIG. 7, the support member 37 has a rectangular base portion 38 in plan view. On each side edge in the longitudinal direction of the base portion 38, hook portions 61 are formed with a predetermined interval. In addition, a pair of claw portions 62 are erected at the center portion of the upper surface of the base portion 38 so as to face each other in the lateral direction. On the lower surface of each claw portion 62, a convex portion 63 is formed as a regulating member. On the upper surface of the base portion 38, the substrate portion 56 of the position detection sensor 55 is supported between the claw portions 62.

  The rotation transmission member 36 is positioned relative to the position detection sensor 55 by inserting the lower end 71a of the rotation shaft 71 into the D-cut 57 of the position detection sensor 55 supported by the substrate portion 56, and is positioned at the position. The detection sensor 55 is supported so as to be rotatable and movable in the vertical direction. Further, the disk part 72 is located below the respective claw parts 62 of the support member 37.

  A coil spring 77 is interposed between the disk part 72 of the rotation transmitting member 36 and the position detection sensor 55 to urge the disk part 72 upward. When the concave portions 75 of the disk portion 72 and the convex portions 63 of the claw portions 62 of the support member 37 correspond to each other in the vertical direction, when the disk portion 72 is urged by the coil spring 77, the convex portions 63 are The rotation of the rotation transmitting member 36 is restricted by engaging with the recess 75. When the rotation of the rotation transmitting member 36 is thus restricted, the rotation of the D cut 57 of the position detection sensor 55 is also restricted. When the disk portion 72 is pressed downward against the urging force of the coil spring 77 and each concave portion 75 is separated from each convex portion 63, the rotation transmitting member 36 can rotate together with the D cut 57. In other words, the rotation transmitting member 36 includes a restriction position where the rotation is restricted by the engagement of the concave portions 75 and the convex portions 63, and an allowable position where the rotation of the concave portions 75 is separated from the convex portions 63. Can be switched by pressing the disk part 72 downward.

  In the sheet feeding device 4 having the above configuration, in order to mount the pair of side guides 32 on the tray 31, first, the pair of side guides 32 is assembled to the cover member 43. At this time, when the cover member 43 is sandwiched between the flat portions 46 of the pair of side guides 32 and the rack 51, the ribs 45 formed on the back surface of the cover member 43 engage with the grooves 51 a formed in the rack 51. Thus, the cover member 43 and each rack 51 are assembled. Each rack 51 is accommodated in the recess 41 and the upper portion of the rack 51 is covered with a cover member 43. Thereby, the pair of side guides 32 can slide on the upper surface of the cover member 43. Then, the pair of side guides 32 are slid on the cover member 43 at a predetermined interval (for example, the interval of the maximum sheet passing width).

  Next, when the tray 31 is turned over, the ring portion 44 formed on the back surface of the cover member 43 is exposed from the opening 41 a formed in the recess 41. Therefore, the boss 52a of the pinion 52 is fitted to the ring portion 44 through the opening 41a, and the pinion 52 is engaged with each rack 51. At this time, the pinion 52 is meshed with the rack 51 of the pair of side guides 32 positioned at the maximum sheet passing width.

  On the other hand, in the rotation transmission mechanism 35, the convex part 63 of the claw part 62 is engaged with the concave part 75 of the rotation transmission member 36, and the rotation transmission member 36 is supported by the control position. And the output value of the position detection sensor 55 of the detection apparatus 34 is set to a reference value in a state where the rotation of the rotation transmitting member 36 is restricted in this way.

  Next, the support member 37 is attached to the opening 41 a of the recess 41 from the rear surface of the tray 31. Specifically, as shown in FIG. 8, the elastic shaft 73 of the rotation transmitting member 36 is inserted into the through hole 53 of the pinion 52 through the opening 41a, and each hook portion 61 of the support member 37 is connected to the opening 41a side. The support member 37 is attached to the tray 31 by being locked to the edge.

  Here, when the elastic shaft 73 is inserted through the through-hole 53, the elastic shaft 73 is inserted while being elastically deformed in the inward direction, and after the insertion, the elastic shaft 73 is elastically deformed in the diameter increasing direction, so that the outer surface of the bent portion 73a is the through-hole 53 abuts on the side surface. The pinion 52 is connected to the rotation transmission member 36 so as to be integrally rotatable at an arbitrary relative position around the elastic shaft 73 by the frictional force between the bent portion 73a and the through hole 53. This position becomes the rotation start position of the pinion 52. Here, the frictional force between the pinion 52 and the elastic shaft 73 is set larger than the rotational torque of the D-cut 57 of the position detection sensor 55.

  When each hook portion 61 of the rotation transmitting member 36 is locked to the side edge of the opening 41 a, the rotation transmitting member 36 is pressed against the cover member 43 through the pinion 52 and resists the biasing force of the coil spring 77. As shown in FIG. 9, the concave portion 75 is separated from the convex portion 63, and the rotation transmitting member 36 is switched to the allowable position. Thereby, the rotation transmission member 36, that is, the pinion 52 can rotate integrally with the D-cut 57 of the position detection sensor 55.

  Next, the sheet width detection operation will be described. As described above, a maximum sheet passing width is provided between the pair of side guides 32 in advance. When a sheet having a width smaller than the maximum sheet passing width is placed on the placing surface 42 of the tray 31, one side guide 32 is slid toward the side edge in the width direction of the sheet. Then, the other side guide 32 slides by the same distance in synchronism with the approaching direction by the slide mechanism 33, and the side guide 32 comes into contact with both side edges in the paper width direction.

  In the slide mechanism 33, when the pinion 52 is rotated by the sliding of each side guide 32, the D-cut 57 of the position detection sensor 55 is rotated via the rotation transmission member 36. As described above, the frictional force between the pinion 52 and the elastic shaft 73 is set to be larger than the rotational torque of the D-cut 57 of the position detection sensor 55, so that each side guide 32 is slid through the rack 51. When the pinion 52 rotates, the pinion 52 and the rotation transmission member 36 rotate together, and the rotation transmission member 36 can transmit the rotation of the pinion 52 to the D-cut 57 of the position detection sensor 55. In the position detection sensor 55, the output value changes from the reference value by the rotation of the pinion 52 from the rotation start position. That is, the resistance value of the variable resistor of the position detection sensor 55 changes, and a voltage corresponding to the changed resistance value is output. In the detection device 34, the rotation angle of the D-cut 57 is calculated based on this output voltage, and the slide distance of the side guide 32 is calculated. Then, the sheet width is calculated by subtracting the sliding distance of each side guide 32 from the maximum sheet passing width. In addition, the space | interval between the side guides 32 in the initial stage can be set to the minimum sheet passing width or another predetermined width.

  When the cover member 43 is mounted in the recess 41, the disk portion 72 and the pinion 52 of the rotation transmitting member 36 are clamped by the ring portion 44 and the coil spring 77 of the cover member 43 as shown in FIG. However, since this clamping force is smaller than the frictional force between the pinion 52 and the elastic shaft 73, the pinion 52 and the rotation transmitting member 36 can rotate together.

  As described above, in the paper feeding device 4 according to the present invention, the pinion 52 in which the pair of racks 51 are normally engaged is connected to the position detection sensor 55 via the rotation transmission member 36. The rotation angle of the pinion 52 from the position where the guide 32 starts to slide toward the side edge in the width direction of the paper can be measured by the position detection sensor 55, and the width of the paper can be accurately detected by the detection device 34. Can do.

  When the rotation shaft of the pinion 52 is integrally connected to the position detection sensor 55, when the rack 51 is engaged with the pinion 52 after the position detection sensor 55 is initially set, the teeth of the pinion 52 and the rack If the position of the tooth 51 is shifted, the pinion 52 rotates until the teeth are completely engaged, and the D-cut 57 of the position detection sensor 55 also rotates together with the pinion 52. Then, the initially set reference value changes, and the paper width cannot be detected accurately. In the present invention, after the teeth of the pinion 52 and the teeth of the rack 51 are normally engaged, the pinion 52 is connected to the D-cut 57 via the rotation transmission member 36, so that the pair of racks 51 are normally engaged. The rotation of the combined pinion 52 from the rotation start position can be accurately detected by a change from the reference value of the output value of the position detection sensor 55.

  Further, by attaching the cover member 43 conventionally provided in the paper feeding device 4 to the concave portion 41 of the tray 31, the pair of side guides 32 is attached to the concave portion 41 of the tray 31, and the rotation transmission member 36 and Since the engagement with the regulating member 37 is released, there is no need to provide a dedicated member or add a dedicated process. Further, since the pair of side guides 32 are provided so as to slide on the upper surface of the cover member 43, the pair of side guides 32 and the cover member 43 can be assembled in a compact manner, and the pair of side guides 32 can be attached to the tray. It becomes easy to attach to the recess 41 of 31.

  Further, since the pinion 52 and the rotation transmission member 36 are connected by the elastic shaft 73 that can be elastically deformed in the radial direction, they can be connected to each other so as to be integrally rotatable at an arbitrary relative position with a simple configuration.

  The elastic shaft 73 may be a solid elastic body that is formed of a material having a high friction coefficient (for example, rubber) and is deformable in the radial direction. A rubber washer may be interposed between the elastic shaft 73 and the through hole 53.

  Further, in order to increase the frictional force between the pinion 52 and the rotation transmission member 36, the contact surface between the disk portion 72 and the pinion 52 of the rotation transmission member 36 is roughened, or between the disk portion 72 and the pinion 52. The frictional force may be increased by interposing a rubber washer. In this way, even if the frictional force between the pinion 52 and the rotation transmission member 36 is increased and the rotational friction of the pinion 52 is increased, the force that slides each side guide 32 is larger. There is no problem in the width adjustment work by the guide 32. Furthermore, by increasing the rotational friction of the pinion 52, an effect that the inadvertent movement of the pair of side guides 32 can be prevented is also obtained.

  In addition, between the lower end surface of the coil spring 77 and the upper surface of the position detection sensor 55, between the upper end surface of the coil spring 77 and the lower surface of the disk part 72, and between the ring part 44 and the pinion 52 of the cover member 43. Even if the spring pressure of the coil spring 77 is increased by inserting a sliding washer, the pinion 52 and the rotation transmission member 36 can rotate integrally without being interfered with the coil spring 77 and the cover member 43. You can also

  In this embodiment, the pair of side guides 32 is assembled to the cover member 43 and then attached to the recess 41 of the tray 31. However, the pair of side guides 32 is attached to the recess 41 without using the cover member 43. May be. In the present embodiment, the pair of side guides 32 are mounted on the tray 31, and then the support member 37 of the rotation transmission mechanism 35 is mounted on the tray 31 to connect the rotation transmission member 36 to the pinion 52. The order of attachment to 31 may be reversed. That is, the support member 37 of the rotation transmission mechanism 35 is mounted on the tray 31 and the position detection sensor 55 is initialized, and then the pair of side guides 32 are mounted on the tray 31 to connect the pinion 52 to the rotation transmission member 36. You may do it. However, since the pair of side guides 32 and the slide mechanism 33 are larger in size than the support member 37, the rotation transmission member 36 supported by the support member 37 having a smaller size is positioned and connected to the pinion 52. However, it is easy to connect. Furthermore, the rotation transmission member 36 may be pressed by the ring portion 44 of the cover member 43.

  Further, as shown in FIG. 10, a triangular pyramid-shaped convex portion 81 may be formed at the center of the ring portion 44 of the cover member 43. In this case, when the cover member 43 is mounted, the ring portion 44 presses the pinion 52, and the convex portion 81 enters from the opening at the upper end of the elastic shaft 73, and elastically deforms the elastic shaft 73 in the diameter increasing direction. Thereby, the frictional force between the elastic shaft 73 and the pinion 52 can be increased, and the connection strength between the pinion 52 and the rotation transmitting member 36 can be increased. Also in this case, the frictional force between the convex portion 81 of the cover member 43 and the elastic shaft 73 is set to be smaller than the frictional force between the elastic shaft 73 and the side surface of the through hole 53 of the pinion 52. Has been.

  Further, in the embodiment of the present invention, the case where the configuration of the present invention is applied to the printer 1 has been described. However, in another different embodiment, the present invention is applied to an image forming apparatus other than the printer 1 such as a copying machine, a facsimile machine, and a multifunction machine. You may apply the structure of invention.

  Furthermore, since the above description of the embodiment of the present invention describes a preferred embodiment of the paper feeding device and the image forming apparatus according to the present invention, various technically preferable limitations are attached. However, the technical scope of the present invention is not limited to these embodiments unless specifically described to limit the present invention. That is, the above-described components in the embodiment of the present invention can be appropriately replaced with existing components and the like, and various variations including combinations with other existing components are possible. The description of the embodiment of the present invention described above does not limit the contents of the invention described in the claims.

1 Printer (image forming device)
4 Feeder 31 Tray 32 Side guide 33 Slide mechanism 34 Detection device 36 Rotation transmission member 37 Support member 41 Recess 42 Placement surface 43 Cover member 44 Ring portion 51 Rack 52 Pinion 52a Boss 53 Through hole (hole)
55 Position detection sensor (sensor member)
57 D-cut (movable part)
63 Restriction member 73 Elastic shaft 73a Bending portion 77 Coil spring (biasing member)
81 Convex

Claims (9)

A tray on which paper is placed;
A pair of side guides that are supported by the tray so as to be slidable in a direction away from each other and regulate the position in the width direction of the paper;
A slide mechanism that has a pair of racks provided on each of the pair of side guides and a pinion that engages with the pair of racks, and is mounted on the tray;
A sensor having a movable part, the output value of which varies according to the amount of rotation of the movable part;
A rotation transmission member connected to the pinion so as to be integrally rotatable with the pinion at an arbitrary relative position around the rotation axis of the pinion; and
A regulating member that engages with the rotation transmission member connected to the movable part and regulates the rotation of the rotation transmission member;
A support member that supports the rotation transmission member so as to be switchable between a restriction position that engages with the restriction member and restricts rotation, and an allowable position that releases the engagement with the restriction member and allows rotation. ,
A detection device that detects the sliding distance of the pair of side guides from the output value of the sensor according to the rotation amount of the pinion transmitted to the movable part via the rotation transmission member;
With
By engaging the pinion with the rack in a state where the pair of side guides are slid to a predetermined distance, and connecting the pinion to the rotation transmission member switched to the restriction position, the rotation transmission member Is switched from the restriction position to the permissible position, and the rotation of the pinion is transmitted to the movable part via the rotation transmission member, and the output of the sensor according to the amount of rotation from the rotation start position of the movable part The sheet feeding device according to claim 1, wherein a sliding distance of the pair of side guides from the predetermined distance can be detected by the detecting device by a displacement of the value. The support member is detachably provided on the tray,
The sheet feeding device according to claim 1, wherein the sensor, the rotation transmission member, and the restriction member are supported by the support member. The tray
A placement surface on which the paper is placed;
A recess formed along the width direction of the paper, and in which the slide mechanism and the support member are mounted;
A cover member for opening and closing the recess,
Supporting the slide mechanism by sliding the pair of side guides to the predetermined distance on the cover member;
Closing the recess with the cover member and mounting the slide mechanism in the recess;
The sheet feeding device according to claim 2, wherein the rotation transmission member is switched to the allowable position by connecting the rotation transmission member to the pinion and mounting the support member in the recess. A cylindrical ring portion is erected on the back surface of the cover member,
The pinion is formed with a boss that can be fitted to the ring part, and the pinion is rotatably supported by the cover member by fitting the boss to the ring part. The sheet feeding device according to claim 3. The support member includes a biasing member that biases the rotation transmitting member to the restriction position,
By mounting the support member in the recess and closing the recess with the cover member, the rotation transmission member is pressed by the cover member and separated from the regulating member against the biasing force of the biasing member. The sheet feeding device according to claim 2, wherein the sheet feeding device is switched to the permissible position.   One of the pinion and the rotation transmission member is formed with a hole on the rotation shaft of the pinion, and the other is formed with an elastic shaft that fits into the hole and is elastically deformable in the radial direction. The pinion and the rotation transmission member are connected so as to be integrally rotatable at an arbitrary relative position around the rotation axis of the pinion by a frictional force between the side surface of the hole and the elastic shaft. The sheet feeding device according to claim 1, wherein:   The sheet feeding device according to claim 6, wherein the elastic shaft has a cylindrical shape, and a bent portion that is bent in the diameter increasing direction is formed along the circumferential direction.   The sheet feeding device according to claim 2, wherein the pair of side guides slide on an upper surface of the cover member.   An image forming apparatus comprising the paper feeding device according to claim 1.

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