Sheet conveying device

Abstract

The invention provides a sheet conveying device capable of accurately detecting the position of a first side guide. The present invention is provided with: a sheet tray on which a sheet fed in a feeding direction is placed; a first side guide that moves linearly in a width direction orthogonal to the feeding direction and positions the sheet on the sheet tray in the width direction; a moving member that moves linearly in the width direction by coming into contact with the first side guide; a sensor that outputs a signal corresponding to the position of the moving member; and a control section that detects a position of the first side guide on the basis of a signal of the sensor.

Description

Technical Field

[0001] The present invention relates to a sheet conveying device. Background Art

[0002] Patent Document 1 discloses an example of an existing sheet conveying device. In this sheet conveying device, as shown therein, sheets are stacked in a cassette and fed in the feeding direction. As shown therein, a lateral restricting plate linearly moves in the width direction orthogonal to the feeding direction and positions the sheets on the cassette in the width direction. As shown therein, a cam has an arm. By the arm abutting against the lateral restricting plate, the cam rotates about a rotation axis. A switch outputs an ON / OFF signal corresponding to the position of a cam pressing projection that rotates. As shown therein, a controller unit detects the position of the lateral restricting plate based on the signal of the switch and determines the size of the sheets stacked on the cassette. Figure 2 As shown therein, sheets are stacked in a cassette and fed in the feeding direction. Figure 1 As shown therein, a lateral restricting plate linearly moves in the width direction orthogonal to the feeding direction and positions the sheets on the cassette in the width direction. Figure 4 As shown therein, a cam has an arm. By the arm abutting against the lateral restricting plate, the cam rotates about a rotation axis. A switch outputs an ON / OFF signal corresponding to the position of a cam pressing projection that rotates. Figure 2 As shown therein, a controller unit detects the position of the lateral restricting plate based on the signal of the switch and determines the size of the sheets stacked on the cassette.

[0003] Prior Art Documents

[0004] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2001 - 124504

[0005] Problems to be Solved by the Invention

[0006] However, in the above-described existing sheet conveying device, the moving direction of the lateral restricting plate, i.e., the linear movement in the width direction, is different from the moving direction of the cam that moves by abutting against the lateral restricting plate, i.e., the rotation about the rotation axis.

[0007] According to this structure, there is a concern that the operation of the cam may not fully follow the position of the lateral restricting plate, and correspondingly, there is a concern that the ON / OFF signal output by the switch may easily become unstable. As a result, there is a concern that the controller unit may have difficulty accurately detecting the position of the lateral restricting plate based on the signal of the switch. Summary of the Invention

[0008] In view of the above existing situation, an object of the present invention is to provide a sheet conveying device capable of accurately detecting the position of a first side guide.

[0009] Means for Solving the Technical Problems

[0010] The sheet conveying device of the present invention includes:

[0011] a sheet tray on which sheets fed in the feeding direction are placed;

[0012] a first side guide that linearly moves in the width direction orthogonal to the feeding direction and positions the sheets on the sheet tray in the width direction;

[0013] A moving part that linearly moves in the width direction by abutting against the first side guide;

[0014] A sensor that outputs a signal corresponding to the position of the moving part; and

[0015] A control unit that detects the position of the first side guide based on the signal from the sensor.

[0016] In the sheet conveying device of the present invention, the moving direction of the first side guide and the moving direction of the moving part that moves by abutting against the first side guide are both linear movements in the width direction, which are the same.

[0017] According to this structure, the movement of the moving part can reliably follow the position of the first side guide. Therefore, the signal output by the sensor according to the position of the moving part is difficult to fluctuate. As a result, the control unit can accurately detect the position of the first side guide based on the signal from the sensor.

[0018] Therefore, the sheet conveying device of the present invention can accurately detect the position of the first side guide. As a result, the size of the sheet placed on the sheet tray can be accurately determined. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a perspective view of the image forming apparatus of the embodiment.

[0020] Figure 2 It is a schematic sectional view of the image forming apparatus of the embodiment.

[0021] Figure 3 It is a perspective view of the sheet tray, the first side guide, the second side guide, the moving part, and the contact sensor.

[0022] Figure 4 It is a partial perspective view of the side frame observed from the sheet tray side.

[0023] Figure 5 It is a partial perspective view of the side frame observed from the side opposite to the sheet tray.

[0024] Figure 6 It is a partial perspective view of the side frame observed from the side opposite to the sheet tray.

[0025] Figure 7 It is a perspective view of the first side guide, the second side guide, and the rack and pinion mechanism.

[0026] Figure 8 It is a partial perspective view of the first side guide.

[0027] Figure 9 It is a partial perspective view of the first side guide.

[0028] Figure 10 It is a partial bottom surface view of the compression coil spring showing the sheet tray, rack and pinion mechanism, moving parts, etc.

[0029] Figure 11 It shows Figure 2 A partial sectional view of the A - A section.

[0030] Figure 12 It is a perspective view of the moving part, compression coil spring, and contact sensor.

[0031] Figure 13 It is a partial side view showing a part of the side frame, moving part, and contact sensor.

[0032] Figure 14 It shows Figure 2 A partial sectional view of the B - B section, showing the state where the first side guide positions the A4 - sized sheet on the sheet tray in the width direction.

[0033] Figure 15 It shows Figure 2 A partial sectional view of the C - C section, showing the state where the first side guide positions the A4 - sized sheet on the sheet tray in the width direction.

[0034] Figure 16 It is the same as Figure 14 A partial sectional view, showing the state where the first side guide positions the sheet smaller than A4 size on the sheet tray in the width direction.

[0035] Figure 17 It is the same as Figure 15 A partial sectional view, showing the state where the first side guide positions the sheet smaller than A4 size on the sheet tray in the width direction.

[0036] Figure 18 It is a partial schematic view explaining the backlash of the meshing of the first rack tooth in the rack and pinion mechanism with respect to the gear.

[0037] Figure 19 It is a partial perspective view of the first side guide related to the image forming apparatus of the modified example.

[0038] Symbol Explanation

[0039] 1…Sheet conveying device (image forming apparatus), DF1…Feeding direction

[0040] SH…Sheet, 100…Sheet tray

[0041] 110… First side guide, 50… Moving part

[0042] 70… Sensor (contact sensor), C1… Control unit

[0043] 90… Frame (side frame)

[0044] 75… Sensor actuator, 71… Sensor body

[0045] 51… Guided part, 55… Restricted part

[0046] 57… Sensor contact part, 53… Intermediate part

[0047] 59… Biasing spring (compression coil spring), X59… Coil axis

[0048] 51T… Contact surface (third contact surface), 51D… Groove

[0049] 120… Second side guide, 150… Rack and pinion mechanism

[0050] 153… Gear, 151G… First rack tooth

[0051] 151… First rack part, 152G… Second rack tooth

[0052] 152… Second rack part, 105A… First restricting surface

[0053] 105B… Second restricting surface, 129Q… Locking claw, 129P… Gripping part. Detailed implementation mode

[0054] Hereinafter, embodiments in which the present invention is embodied will be described with reference to the accompanying drawings.

[0055] (Embodiment)

[0056] As Figure 1 shown, the image forming apparatus 1 of the embodiment is an example of a specific mode of the sheet conveying apparatus of the present invention.

[0057] In Figure 1 , the side of the apparatus main body 9 provided with the opening 9H and the front cover 9F is defined as the front of the image forming apparatus 1, and the left hand side when facing the opening 9H and the front cover 9F is defined as the left side of the image forming apparatus 1, thereby showing the front-back, left-right, and up-down directions.

[0058] In the present embodiment, the width direction of the image forming apparatus 1 is the left-right direction. One side of the width direction is the left side, and the other side of the width direction is the right side. Figure 2 All the directions shown in the following figures are the same asFigure 1 displayed corresponding to the respective directions shown.

[0059] <Schematic Structure of Image Forming Apparatus>

[0060] As Figure 2 shown, the image forming apparatus 1 is a monochrome laser printer that forms an image on a sheet SH by an electrophotographic method. The image forming apparatus 1 includes: a substantially box-shaped apparatus main body 9, an image forming unit 3 housed in the apparatus main body 9, a sheet tray 100, a feeding unit 20, a discharge roller pair 29, and a control unit C1.

[0061] The control unit C1 is an electronic circuit unit configured to include a CPU, an interface circuit, and a storage unit (not shown). The control unit C1 comprehensively controls each part of the image forming apparatus 1 including the control of the image forming unit 3, the feeding unit 20, and the discharge roller pair 29.

[0062] The sheet tray 100 is located below the image forming unit 3 and at the bottom of the apparatus main body 9. As Figure 3 shown, the sheet tray 100 is a resin-made member having a substantially flat plate shape extending in the front-rear direction and the left-right direction.

[0063] The sheet SH before image formation is placed on the sheet tray 100 in a stacked state. The sheet tray 100 has a size capable of placing sheets SH such as A4 to A6 sizes and postcards. The sheet SH is paper, an OHP sheet, or the like.

[0064] The image forming apparatus 1 includes a first side guide 110 and a second side guide 120 disposed on the sheet tray 100. The first side guide 110 is located on one side in the width direction, that is, the left side, with respect to the sheet SH on the sheet tray 100. The second side guide 120 is located on the other side in the width direction, that is, the right side, with respect to the sheet SH on the sheet tray 100.

[0065] The first side guide 110 and the second side guide 120 position the sheet SH on the sheet tray 100 in the width direction by linearly moving so as to approach and separate from each other in the width direction. The specific structures of the first side guide 110 and the second side guide 120 will be described in detail later.

[0066] Swing shafts 109L and 109R are formed at the front left corner and the front right corner of the sheet tray 100. The swing shafts 109L and 109R are centered on a swing axis X100 extending in the left-right direction.

[0067] Figure 1 And Figures 4 to 6As shown, the apparatus main body 9 has side frames 90. The side frame 90 is an example of the "frame" of the present invention. In the present embodiment, the side frame 90 is a resin component manufactured by injection molding of a thermoplastic resin or the like. As Figure 1 shown, the side frame 90 is located to the left of the sheet tray 100.

[0068] In Figure 1 , a part of the side frame 90 is illustrated, but the side frame 90 extends along the left side surface, the front-rear direction, and the up-down direction of the apparatus main body 9.

[0069] As Figure 4 shown, a shaft hole 90H centered on the swing axis X100 is provided through the corner portion in front of and below the side frame 90. At a position slightly separated from the shaft hole 90H forward in the side frame 90, a support shaft 90F is formed so as to protrude rightward.

[0070] Although not shown, the apparatus main body 9 has other side frames located to the right of the sheet tray 100 and paired with the side frame 90. A shaft hole having the same structure slightly different from the shaft hole 90H is also provided through in the other side frame, and a support shaft having the same structure slightly different from the support shaft 90F is also formed in the other side frame.

[0071] As Figure 1 shown, the shaft hole 90H of the side frame 90 supports the swing shaft 109L of the sheet tray 100. Although not shown, the shaft hole of the other side frame not shown supports the swing shaft 109R of the sheet tray 100. Thus, the apparatus main body 9 supports the sheet tray 100 so as to be swingable about the swing axis X100. 1]

[0072] The support shaft 90F of the side frame 90 and the support shaft of the other side frame not shown support the front cover 9F so as to be swingable.

[0073] An opening 9H is provided in the lower part of the front surface of the apparatus main body 9. The length of the opening 9H in the left-right direction is larger than the length of the sheet tray 100 in the left-right direction. As Figure 2 shown, the upper end edge of the opening 9H is located at a position separated upward from the sheet tray 100 to such an extent that it does not hinder the operation when the user places the sheets SH in a stacked state on the sheet tray 100. In addition, the sheet tray 100 in the present embodiment cannot be detached from and attached to the apparatus main body 9. Therefore, when the user places the sheets SH, the sheets SH are inserted onto the sheet tray 100 from the opening 9H without moving the sheet tray 100.

[0074] The front cover 9F opens the opening 9H in a state where it is located in front of the sheet tray 100 and extends in the front-rear direction and the left-right direction. In this state, the front cover 9F supports the portion of the sheet SH placed on the sheet tray 100 that protrudes forward from the opening 9H.

[0075] Although not shown in the figure, the front cover 9F closes the opening 9H by swinging and rising from the Figure 1 and Figure 2 shown state.

[0076] As Figure 2 shown, a discharge tray 9T is formed on the upper surface of the apparatus main body 9. The discharge tray 9T supports the sheet SH after the image formation is completed.

[0077] The feeding unit 20 is located below the image forming unit 3 and near the rear surface and the bottom of the apparatus main body 9. The feeding unit 20 has a feeding roller 21, a separating roller 22, a separating pad 22A, and a pair of conveying rollers 23 arranged along the conveying path P1. And, the feeding unit 20 has a rod 20L that abuts against the lower surface of the sheet tray 100 from below.

[0078] The conveying path P1 is a path that advances a short distance backward from the rear end of the sheet tray 100, then changes its orientation, advances upward along the rear surface of the apparatus main body 9, changes its orientation again, and advances forward along the upper surface of the apparatus main body 9 to reach the discharge tray 9T.

[0079] The feeding roller 21 is located at the upstream end of the conveying path P1 and faces the rear end of the sheet tray 100 from above. The rod 20L swings to swing the sheet tray 100 and raise the rear end of the sheet tray 100. As a result, the uppermost sheet SH placed on the sheet tray 100 abuts against the feeding roller 21.

[0080] The feeding roller 21 feeds the uppermost sheet SH placed on the sheet tray 100 in the feeding direction DF1 and sends it out to the conveying path P1. The feeding direction DF1 is a direction that advances substantially horizontally from the front toward the rear and is orthogonal to the width direction. And, the feeding direction DF1 is substantially orthogonal to the up-down direction.

[0081] When multiple sheets SH are stacked on the sheet sent out by the feeding roller 21, the separating roller 22 and the separating pad 22A separate the sheets SH one by one.

[0082] The pair of conveying rollers 23 clamps the sheet SH separated one by one by the separating roller 22 and the separating pad 22A and conveys it upward along the rear surface of the apparatus main body 9.

[0083] In this way, the sheet SH fed by the feeding unit 20 passes through the image forming unit 3 in the middle of the upward extending portion in the conveying path P1.

[0084] The image forming unit 3 includes a developing cartridge 3C, a scanning unit 8, and a fixing unit 7. The developing cartridge 3C, the scanning unit 8, and the fixing unit 7 are supported by a side frame 90 and other side frames (not shown).

[0085] The structure of the developing cartridge 3C is well-known and will be omitted from description. The developing cartridge 3C includes a photosensitive drum 5, a transfer roller 6, a developing roller 3E, a charger 3F, and a toner storage section 3G.

[0086] The photosensitive drum 5 is located midway in an upwardly extending portion of the conveyance path P1. The photosensitive drum 5 rotates about an axis extending in the width direction. The transfer roller 6 is located behind the photosensitive drum 5. The transfer roller 6 rotates while sandwiching the conveyed sheet SH together with the photosensitive drum 5. The developing roller 3E, the charger 3F, and the toner storage section 3G are located around the photosensitive drum 5.

[0087] The scanning unit 8 is located at a position spaced apart from the developing cartridge 3C towards the front. The scanning unit 8 includes a laser light source, a polygon mirror, an fθ lens, a mirror, etc. The scanning unit 8 emits a laser beam rearward and irradiates the photosensitive drum 5.

[0088] As the surface of the photosensitive drum 5 rotates, it is uniformly positively charged by the charger 3F and then exposed by the high-speed scanning of the laser beam irradiated from the scanning unit 8. Thus, an electrostatic latent image corresponding to the image to be formed on the sheet SH is formed on the surface of the photosensitive drum 5.

[0089] Next, the developing roller 3E supplies the toner stored in the toner storage section 3G to the surface of the photosensitive drum 5 corresponding to the electrostatic latent image, forming a toner image. And when the sheet SH conveyed by the conveying roller pair 23 passes between the photosensitive drum 5 and the transfer roller 6, the toner image carried on the surface of the photosensitive drum 5 is transferred to the sheet SH.

[0090] The fixing unit 7 is located above the photosensitive drum 5 and the transfer roller 6 and at a position near the upper end of the rear surface and the rear end of the upper surface of the apparatus main body 9. The fixing unit 7 heats and presses while sandwiching and conveying the sheet SH that has passed between the photosensitive drum 5 and the transfer roller 6 by a heating roller 7A and a pressure roller 7B, thermally fixing the toner image onto the sheet SH.

[0091] The discharge roller pair 29 is located at the downstream end of the conveyance path P1. The discharge roller pair 29 sandwiches the sheet SH that has passed through the fixing unit 7 and is conveyed along the conveyance path P1 and discharges it to the discharge tray 9T.

[0092] <First side guide, second side guide, and rack and pinion mechanism>

[0093] As Figures 7 to 10As shown, the first-side guide member 110 is a resin member integrally formed with a guide portion 111, a sliding portion 113, a first rack portion 151, an abutting portion 115, a connecting portion 116, a first reinforcing rib 117, and a second reinforcing rib 118.

[0094] As Figure 7 , Figure 10 and Figure 11 shown, the second-side guide member 120 is a resin member integrally formed with a guide portion 121, a sliding portion 123, a second rack portion 152, an elastically deformable portion 129, a locking claw 129Q, and a gripping portion 129P.

[0095] In the present embodiment, the first-side guide member 110 and the second-side guide member 120 are manufactured by injection molding of a thermoplastic resin or the like.

[0096] As Figure 7 and Figure 10 shown, the image forming apparatus 1 has a rack and pinion mechanism 150 that brings the first-side guide member 110 and the second-side guide member 120 closer to and separates them from each other in the width direction. The rack and pinion mechanism 150 is configured to include: a gear 153, a first rack portion 151 of the first-side guide member 110, and a second rack portion 152 of the second-side guide member 120.

[0097] <Details of the First-Side Guide Member>

[0098] As Figure 3 shown, in the first-side guide member 110, the guide portion 111 and the sliding portion 113 are located at positions close to the left end of the sheet tray 100.

[0099] The guide portion 111 protrudes upward on the sheet tray 100 and extends along the feeding direction DF1. As Figure 7 , Figure 8 and Figure 9 shown, the sliding portion 113 is connected to the lower end 111D side of the guide portion 111 and extends toward the other side in the width direction, and extends along the feeding direction DF1.

[0100] The guide portion 111 has a substantially rectangular flat plate shape extending in the front-rear direction and the up-down direction. As Figure 7 and Figure 8 shown, the guide portion 111 has a first abutting surface 111T. The first abutting surface 111T is located at the front end portion, the rear end portion, and the intermediate portion in the front-rear direction on the right side surface of the guide portion 111. The first abutting surface 111T abuts against the sheet SH on the sheet tray 100 from one side in the width direction, whereby the guide portion 111 guides the sheet SH.

[0101] As Figures 7 to 9As shown, the sliding portion 113 has a substantially rectangular flat plate shape extending in the front-rear direction and the width direction. The sliding portion 113 supports one end edge side in the width direction of the sheet SH on the lower support sheet tray 100.

[0102] The first rack portion 151 is connected to the middle portion in the front-rear direction on the lower surface of the sliding portion 113 and extends longer toward the other side in the width direction.

[0103] The first rack portion 151 has a first restricted surface 151A and a second restricted surface 151B. The first restricted surface 151A is the front end surface located upstream in the feed direction DF1 of the first rack portion 151 and extending in the width direction. The second restricted surface 151B is the rear end surface located downstream in the feed direction DF1 of the first rack portion 151 and extending in the width direction.

[0104] Moreover, the first rack portion 151 has first rack teeth 151G and a biasing piece 151S. The first rack teeth 151G have a plurality of gear teeth arranged in the width direction and located upstream in the feed direction DF1 of the first rack portion 151. The biasing piece 151S is located downstream in the feed direction DF1 of the first rack portion 151 and protrudes in the width direction in a cantilever beam shape. The biasing piece 151S accumulates resilience by being pressed forward at the tip.

[0105] As Figure 3 and Figure 10 shown, the sheet tray 100 has a guide groove 105. The guide groove 105 is a groove that penetrates the sheet tray 100 in the up-down direction and extends longer in the width direction. The guide groove 105 houses the first rack portion 151 so as to be able to move linearly in the width direction.

[0106] The guide groove 105 has a first restricting surface 105A and a second restricting surface 105B. The first restricting surface 105A is the inner wall surface in the front of the guide groove 105 and extending in the width direction. The second restricting surface 105B is the inner wall surface in the rear of the guide groove 105 and extending in the width direction.

[0107] As Figure 10 shown, the first restricting surface 105A restricts the forward movement of the first rack portion 151 in the upstream direction of the feed direction DF1, that is, forward, by abutting against the first restricted surface 151A of the first rack portion 151.

[0108] The second restricting surface 105B restricts the backward movement of the first rack portion 151 in the downstream direction of the feed direction DF1, that is, backward, by abutting against the second restricted surface 151B of the first rack portion 151.

[0109] The biasing piece 151S of the first rack portion 151 accumulates a restoring force by having its tip pressed by the second restricting surface 105B, and biases the first rack portion 151 forward. By pressing the first restricted surface 151A against the first restricting surface 105A with the biasing piece 151S, rattling of the first rack portion 151 within the guide groove 105 is suppressed.

[0110] The first rack portion 151 is guided by the guide groove 105, such that the first side guide member 110 linearly moves in the width direction integrally with the first rack portion 151.

[0111] As Figure 7 and Figure 9 shown, the contact portion 115 is a small rectangular plate-shaped piece that extends in the front-rear direction and the up-down direction at a position separated from the guide portion 111 in one direction in the width direction. That is, there is a gap between the contact portion 115 and the guide portion 111.

[0112] The upper end of the contact portion 115 is located slightly lower than the upper end of the guide portion 111. The lower end of the contact portion 115 is located near the lower end 111D of the guide portion 111.

[0113] The contact portion 115 has a second contact surface 115T. The second contact surface 115T is the left surface of the contact portion 115 and is located on one side in the width direction relative to the first contact surface 111T. As Figure 3 and Figure 10 shown, the second contact surface 115T contacts a moving member 50 described later from the other side in the width direction.

[0114] As Figure 7 and Figure 9 shown, the connecting portion 116 has a connecting plate portion 116C, connecting ribs 116A, and connecting ribs 116B.

[0115] The connecting plate portion 116C is a small rectangular plate-shaped piece that extends in the front-rear direction and the width direction. The left end of the connecting plate portion 116C is connected to the lower end 115D of the contact portion 115. The right end of the connecting plate portion 116C is connected to the middle portion in the front-rear direction of the left side surface of the guide portion 111.

[0116] The connecting ribs 116A, 116B are small pieces in an inverted "L" shape when viewed in the front-rear direction. The upper end of the connecting rib 116A is connected to the front end of the connecting plate portion 116C. The upper end of the connecting rib 116B is connected to the rear end of the connecting plate portion 116C. The right ends of the connecting ribs 116A, 116B are connected to the left side surface of the guide portion 111. The lower ends of the connecting ribs 116A, 116B extend to the left end of the sliding portion 113.

[0117] That is, the connecting portion 116 extends from the lower end 115D side of the abutting portion 115 toward the lower end 111D side of the guiding portion 111 and connects the abutting portion 115 and the left side surface of the guiding portion 111, and further extends to the left end of the sliding portion 113. As Figure 7 shown, the cross-sectional shape of the portion where the connecting portion 116 is connected to the left side surface of the guiding portion 111 is an inverted "U" shape when observed in the width direction.

[0118] The first reinforcing rib 117 and the second reinforcing rib 118 are small pieces having a triangular shape when observed in the front-rear direction. The first reinforcing rib 117 and the second reinforcing rib 118 are also separated from the guiding portion 111 toward one side in the width direction and have a gap therebetween and the guiding portion 111.

[0119] The first reinforcing rib 117 projects from the front edge, which is the side edge at the upstream in the feeding direction DF1 in the abutting portion 115, toward the other side in the width direction and extends in the up-down direction. The lower end side of the first reinforcing rib 117 is connected to the front end of the connecting plate portion 116C of the connecting portion 116.

[0120] The second reinforcing rib 118 projects from the rear edge, which is the side edge at the downstream in the feeding direction DF1 in the abutting portion 115, toward the other side in the width direction and extends in the up-down direction. The lower end side of the second reinforcing rib 118 is connected to the rear end of the connecting plate portion 116C of the connecting portion 116.

[0121] <Details of the second side guide>

[0122] As Figure 3 shown, in the second side guide 120, the guiding portion 121 and the sliding portion 123 are located at positions close to the right end of the sheet tray 100.

[0123] The guiding portion 121 projects upward on the sheet tray 100 and extends in the feeding direction DF1. The sliding portion 123 is connected to the lower end 121D side of the guiding portion 121 and extends toward one side in the width direction and also extends in the feeding direction DF1.

[0124] As Figure 7 shown, the guiding portion 121 is a substantially rectangular flat plate shape extending in the front-rear direction and the up-down direction. The guiding portion 121 has a sheet abutting surface 121T. The sheet abutting surface 121T is located at the front end portion, the rear end portion, and the intermediate portion in the front-rear direction on the left side surface of the guiding portion 121. The sheet abutting surface 121T abuts against the sheet SH on the sheet tray 100 from the other side in the width direction, whereby the guiding portion 121 guides the sheet SH.

[0125] The sliding portion 123 is a substantially rectangular flat plate shape extending in the front-rear direction and the width direction. The sliding portion 123 supports the edge side on the other side in the width direction of the sheet SH on the sheet tray 100 from below.

[0126] The second rack portion 152 is connected to the middle portion in the front-rear direction on the lower surface of the sliding portion 123, and extends relatively long toward one side in the width direction.

[0127] The second rack portion 152 has restricted surfaces 152A and 152B. The restricted surface 152A is the front end surface located upstream in the feed direction DF1 of the second rack portion 152 and extending in the width direction. The restricted surface 152B is the rear end surface located downstream in the feed direction DF1 of the second rack portion 152 and extending in the width direction.

[0128] Moreover, the second rack portion 152 has second rack teeth 152G and a biasing piece 152S. The second rack teeth 152G are located downstream in the feed direction DF1 of the second rack portion 152 and have a plurality of gear teeth arranged in the width direction. The biasing piece 152S is located upstream in the feed direction DF1 of the second rack portion 152 and protrudes in the width direction in a cantilever shape. The biasing piece 151S accumulates a restoring force by being pressed backward at the tip.

[0129] As Figure 3 and Figure 10 shown, the sheet tray 100 has a guide groove 106. The guide groove 106 is a groove that penetrates the sheet tray 100 in the vertical direction and extends relatively long in the width direction. The guide groove 106 houses the second rack portion 152 so as to be linearly movable in the width direction.

[0130] The guide groove 106 has restricted surfaces 106A and 106B. The restricted surface 106A is the inner wall surface extending in the width direction in the front of the guide groove 106. The restricted surface 106B is the inner wall surface extending in the width direction in the rear of the guide groove 106.

[0131] As Figure 10 shown, the restricted surface 106A restricts the forward movement of the second rack portion 152 in the upstream direction of the feed direction DF1, i.e., forward, by abutting against the restricted surface 152A of the second rack portion 152.

[0132] The restricted surface 106B restricts the backward movement of the second rack portion 152 in the downstream direction of the feed direction DF1, i.e., backward, by abutting against the restricted surface 152B of the second rack portion 152.

[0133] The biasing piece 152S of the second rack portion 152 accumulates a restoring force by being pressed by the restricted surface 106A at the tip and biases the second rack portion 152 backward. By pressing the restricted surface 152B against the restricted surface 106B with the biasing piece 152S, rattling of the second rack portion 152 in the guide groove 106 is suppressed.

[0134] The second rack portion 152 is guided by the guide groove 106, so that the second side guide member 120 and the second rack portion 152 move linearly in the width direction integrally.

[0135] As Figure 7 shown, the elastic deformation portion 129 can be elastically deformed independently of the guide portion 121 and the sliding portion 123 by two grooves formed on the front end side of the guide portion 121 and the sliding portion 123.

[0136] The root portion 129A of the elastic deformation portion 129 is connected to the front end portion of the sliding portion 123. As Figure 11 shown, the elastic deformation portion 129 extends from the root portion 129A toward the other side in the width direction, then bends and extends upward, further bends and extends toward one side in the width direction so as not to interfere with the sheet SH on the sheet tray 100.

[0137] The grasping portion 129P is connected to the top end of the elastic deformation portion 129 and protrudes upward. The locking claw 129Q is formed on the lower bent portion of the elastic deformation portion 129 and protrudes downward.

[0138] As Figure 3 and Figure 11 shown, a locking tooth row 100Q is formed at a position on the upper surface of the sheet tray 100 opposite to the locking claw 129Q. The locking tooth row 100Q has a plurality of locking teeth arranged in the width direction.

[0139] In a state where the grasping portion 129P is not operated by the user, the locking claw 129Q engages with the locking tooth row 100Q. Thus, the second side guide member 120 and the second rack portion 152 cannot move in the width direction.

[0140] When the grasping portion 129P is operated by the user and displaced leftward, the elastic deformation portion 129 is elastically deformed and the locking claw 129Q rises, and the engagement between the locking claw 129Q and the sheet tray 100 is released. Thus, the second side guide member 120 and the second rack portion 152 can move in the width direction.

[0141] <Details of the rack and pinion mechanism>

[0142] As Figure 7 and Figure 10 shown, in the rack and pinion mechanism 150, the gear 153 is rotatably supported on the lower surface side of the sheet tray 100 between the first side guide member 110 and the second side guide member 120 in the width direction.

[0143] The first rack portion 151 is located behind the gear 153. The first rack teeth 151G mesh with the gear 153. The second rack portion 152 is located in front of the gear 153. The second rack teeth 152G mesh with the gear 153 on the side opposite to the first rack portion 151.

[0144] In this way, the rack and pinion mechanism 150 connects the first side guide 110 and the second side guide 120.

[0145] In a state where the gripping portion 129P is not operated by the user, the first side guide 110 and the first rack portion 151, similarly to the second side guide 120 and the second rack portion 152, cannot move in the width direction.

[0146] In a state where the gripping portion 129P is operated by the user to release the engagement between the locking claw 129Q and the sheet tray 100, the first side guide 110 and the first rack portion 151, similarly to the second side guide 120 and the second rack portion 152, can move in the width direction.

[0147] Moreover, when the user linearly moves the second side guide 120 in the width direction, this movement is transmitted to the first side guide 110 via the rack and pinion mechanism 150. As a result, the first side guide 110 and the second side guide 120 approach and separate in the width direction.

[0148] <Moving member, compression coil spring, and contact sensor>

[0149] When the control unit C1 controls the image forming operation and the like performed by the image forming apparatus 1, it performs adjustments corresponding to the size of the sheet SH on the sheet tray 100. For example, a sheet SH having a size smaller than the A4 size requires less time for the conveyance path P1 than a sheet SH having the A4 size. Therefore, when the size of the sheet SH on the sheet tray 100 is smaller than the A4 size, the control unit C1 makes adjustments so as to shorten the working time of the developing cartridge 3C, the scanning unit 8, and the like.

[0150] As Figure 2 , Figure 3 and Figures 12 to 17 shown, the image forming apparatus 1 includes a moving member 50, a compression coil spring 59, and a contact sensor 70 so that the control unit C1 can accurately determine the size of the sheet SH placed on the sheet tray 100.

[0151] The compression coil spring 59 is an example of the "biasing spring" of the present invention. The contact sensor 70 is an example of the "sensor" of the present invention. In the present embodiment, the control unit C1 determines whether the size of the sheet SH on the sheet tray 100 is the A4 size or a size smaller than the A4 size.

[0152] As Figure 12 and Figure 13 shown, the moving member 50 is a resin member integrally having a guided portion 51, an intermediate portion 53, a sensor abutting portion 57, and a restricted portion 55. In the present embodiment, the moving member 50 is manufactured by injection molding of a thermoplastic resin or the like.

[0153] The guided portion 51 has a substantially prism shape extending in the width direction. The guided portion 51 has a groove 51D, ribs 52A, and ribs 52B.

[0154] The groove 51D is recessed upward from the lower surface of the guided portion 51 and extends in the width direction. One side in the width direction of the groove 51D is open. The guided portion 51 houses a compression coil spring 59 in the groove 51D. The other end of the compression coil spring 59 in the width direction abuts against the inner wall surface of the other side in the width direction of the groove 51D, so that the compression coil spring 59 is locked to the moving member 50. The compression coil spring 59 has a spiral axis X59 extending in the width direction.

[0155] The rib 52A projects forward from the left portion of the front side surface of the guided portion 51 and extends in the width direction. The rib 52B projects forward from the left portion of the rear side surface of the guided portion 51 and extends in the width direction.

[0156] The guided portion 51 has a third abutting surface 51T. The third abutting surface 51T is an example of the "abutting surface" of the present invention. The third abutting surface 51T is the right end surface in the guided portion 51. In other words, the third abutting surface 51T is formed at the end opposite to the first side guide 110 on the other side in the width direction of the guided portion 51. The third abutting surface 51T intersects the spiral axis X59.

[0157] The intermediate portion 53 extends upward from the guided portion 51 and then extends toward the upstream in the feed direction DF1. A plurality of reinforcing ribs 53R are formed inside the portion of the intermediate portion 53 that bends from upward to forward. The front end 53A of the intermediate portion 53 is located at a position where the plurality of reinforcing ribs 53R disappear.

[0158] The sensor abutting portion 57 is connected to the front end 53A of the intermediate portion 53. The sensor abutting portion 57 extends in a flat plate shape in the front-rear direction and the width direction.

[0159] The restricted portion 55 is connected to the front end of the sensor abutting portion 57. The restricted portion 55 is a rib shape that projects upward a short distance from the front end of the sensor abutting portion 57 and extends in the width direction.

[0160] As Figure 13As shown, when viewed in the width direction, the sensor abutting portion 57 is located between the guided portion 51 and the restricted portion 55. The restricted portion 55 and the sensor abutting portion 57 are located above the guided portion 51 and upstream in the feed direction DF1.

[0161] The contact sensor 70 is a known microswitch. The contact sensor 70 has a sensor actuator 75 and a sensor body 71. The sensor body 71 supports the sensor actuator 75 so as to be swingable. The sensor actuator 75 protrudes upward and toward one side in the width direction on the upper surface side of the sensor body 71.

[0162] As Figures 4 to 6 shown, the side frame 90 has a guide hole 95H. The guide hole 95H is a rectangular hole that penetrates the side frame 90 in the width direction.

[0163] As Figure 5 and Figure 6 shown, the side frame 90 has a guide pedestal 91, a restricting rib 92A, and a restricting rib 92B. The guide pedestal 91, the restricting rib 92A, and the restricting rib 92B are connected to the wall portion of the side frame 90 where the guide hole 95H is formed from one side in the width direction.

[0164] The upper surface of the guide pedestal 91 is flush with the inner wall surface below the guide hole 95H. At the left end of the upper surface of the guide pedestal 91, a spring locking portion 91S is formed to protrude upward.

[0165] The restricting rib 92A and the restricting rib 92B extend in the front-rear direction and the width direction, respectively, at positions spaced upward from the upper surface of the guide pedestal 91. The restricting rib 92A is located in front of the guide pedestal 91. The restricting rib 92B is located behind the guide pedestal 91. The rear end surface of the restricting rib 92A is flush with the inner wall surface in front of the guide hole 95H. The front end surface of the restricting rib 92B is flush with the inner wall surface behind the guide hole 95H.

[0166] As Figure 13 and Figure 14 shown, the lower surface of the guided portion 51 is guided to be movable in the width direction by the upper surface of the guide pedestal 91 and the inner wall surface below the guide hole 95H.

[0167] As Figure 13 shown, the front side surface of the guided portion 51 is guided to be movable in the width direction by the rear end surface of the restricting rib 92A and the inner wall surface in front of the guide hole 95H. The rear side surface of the guided portion 51 is guided to be movable in the width direction by the front end surface of the restricting rib 92B and the inner wall surface behind the guide hole 95H.

[0168] The upward movement of the ribs 52A and 52B of the guided portion 51 is restricted by the restricting ribs 92A and 92B.

[0169] Thus, the guided portion 51 is guided by the side frame 90 to linearly move in the width direction.

[0170] As Figure 14 shown, one end portion of the compression coil spring 59 in the width direction is caught by the spring catch portion 91S. The compression coil spring 59 biases the moving member 50 toward the other side in the width direction.

[0171] As Figure 6 , Figure 13 and Figure 15 shown, on the side frame 90, a lower surface of a rib that is located above the restricted portion 55, protrudes toward one side in the width direction, and extends in the front-rear direction forms a restricting surface 93. The restricting surface 93 is a flat surface that extends downward in the width direction.

[0172] The upper end surface of the restricted portion 55 abuts against the restricting surface 93 from below. The length of the restricting surface 93 in the width direction is approximately the same as the linear movement stroke of the moving member 50. The upward movement of the restricting portion 55 is restricted by the restricting surface 93. The up-down direction is an example of the "first direction orthogonal to the width direction" of the present invention. The upper side is an example of the "one side of the first direction" of the present invention.

[0173] Thus, as Figures 14 to 17 shown, the side frame 90 supports the moving member 50 at a position separated from the first side guide 110 toward one side in the width direction so as to be capable of linearly moving in the width direction.

[0174] The third abutting surface 51T of the moving member 50 can abut against the second abutting surface 115T of the first side guide 110. As Figure 10 shown, the third abutting surface 51T abuts against the second abutting surface 115T between the first restricting surface 105A and the second restricting surface 105B in the feed direction DF1.

[0175] As Figure 14 and Figure 15 shown, when the first side guide 110 moves toward one side in the width direction to guide a sheet SH of A4 size, the third abutting surface 51T abuts against the second abutting surface 115T, whereby the moving member 50 linearly moves toward one side in the width direction against the acting force of the compression coil spring 59.

[0176] As Figure 16 and Figure 17 shown, when the first side guide 110 moves toward the other side in the width direction to guide a sheet SH of a size smaller than A4 size, the moving member 50 linearly moves toward the other side in the width direction while maintaining the state where the third abutting surface 51T abuts against the second abutting surface 115T by the acting force of the compression coil spring 59.

[0177] Also, as Figure 16 shown, by touching the upper edge of the guide hole 95H with the middle part 53 of the moving member 50, the third contact surface 51T is separated from the second contact surface 115T.

[0178] As Figure 5 , Figure 6 and Figure 15 shown, the side frame 90 has a sensor pedestal 97. The sensor pedestal 97 is located above the guide hole 95G and the guide pedestal 91 and upstream in the feed direction DF1. As Figure 6 shown, the sensor pedestal 97 is located directly below the restricting surface 93.

[0179] As Figure 15 shown, the sensor main body 71 is assembled to the sensor pedestal 97, so that the contact sensor 70 is supported by the side frame 90. The signal wiring 71W extends downward from the sensor main body 71. The signal wiring 71W is routed toward the control unit C1. As Figure 13 shown, the sensor main body 71 is located above the guided portion 51 and upstream in the feed direction DF1.

[0180] The sensor contact portion 57 of the moving member 50 is located at a position spaced upward from the sensor main body 71. As Figure 15 shown, the sensor contact portion 57 can contact the sensor actuator 75. When the first side guide 110 moves in one direction in the width direction to guide the A4-size sheet SH, the sensor actuator 75 contacts the sensor contact portion 57 of the moving member 50 that moves together with the first side guide 110, and thereby swings in a manner of falling down toward one side in the width direction and downward.

[0181] As Figure 17 shown, when the first side guide 110 moves in the other direction in the width direction to guide a sheet SH smaller than the A4 size, the sensor actuator 75 separates from the sensor contact portion 57 of the moving member 50 that moves together with the first side guide 110, and thereby swings back to its original position.

[0182] The sensor main body 71 incorporates a switch circuit that switches between connection and disconnection by the swing of the sensor actuator 75. The contact sensor 70 outputs an on (ON) signal or an off (OFF) signal according to the position of the moving member 50.

[0183] Specifically, as Figure 15 shown, when the first side guide 110 is in the position of guiding the A4-size sheet SH and the moving member 50 is in the state of linearly moving to one side in the width direction accordingly, the contact sensor 70 outputs an on (ON) signal.

[0184] On the other hand, as Figure 17 shown, when the first side guide 110 is positioned to guide a sheet SH having a size smaller than the A4 size, and the moving member 50 is accordingly positioned to linearly move to the other position in the width direction, the contact sensor 70 outputs an OFF signal.

[0185] The control unit C1 detects the position of the first side guide 110 based on the signal of the contact sensor 70 transmitted via the signal wiring 71W.

[0186] Specifically, when the signal of the contact sensor 70 is an ON signal, the control unit C1 detects that the first side guide 110 is positioned to guide the sheet SH having the A4 size, and determines that the size of the sheet SH on the sheet tray 100 is the A4 size.

[0187] On the other hand, when the signal of the contact sensor 70 is an OFF signal, the control unit C1 detects that the first side guide 110 is positioned to guide a sheet SH having a size smaller than the A4 size, and determines that the size of the sheet SH on the sheet tray 100 is a size smaller than the A4 size.

[0188] <Effect>

[0189] In the image forming apparatus 1 of the embodiment, as Figures 14 to 17 shown, both the moving direction of the first side guide 110 and the moving direction of the moving member 50 that moves in contact with the first side guide 110 are linear movements in the width direction and are the same.

[0190] According to this structure, the movement of the moving member 50 can reliably follow the position of the first side guide 110. Therefore, it is difficult for the signal output by the contact sensor 70 to fluctuate according to the position of the moving member 50.

[0191] Specifically, as Figure 15 shown, the movement of the moving member 50 can reliably follow the position of the side guide 110 that guides the sheet SH having the A4 size. Therefore, it is difficult for the ON signal output by the contact sensor 70 to fluctuate according to the position of the moving member 50.

[0192] Moreover, Figure 17 shown, the movement of the moving member 50 can reliably follow the position of the side guide 110 that guides a sheet SH having a size smaller than the A4 size. Therefore, it is difficult for the OFF signal output by the contact sensor 70 to fluctuate according to the position of the moving member 50.

[0193] As a result, the control unit C1 can accurately detect the position of the first side guide 110 based on the ON signal or OFF signal of the contact sensor 70.

[0194] Therefore, the image forming apparatus 1 according to the embodiment can accurately detect the position of the first side guide 110. As a result, it is possible to accurately determine whether the size of the sheet SH placed on the sheet tray 100 is the A4 size or a size smaller than the A4 size.

[0195] Moreover, in this image forming apparatus 1, as Figure 12 and Figure 13 shown, the moving member 50 integrally includes a guided portion 51, a restricted portion 55, and a sensor contact portion 57. As Figure 13 , Figure 14 and Figure 16 shown, the guided portion 51 is guided to linearly move in the width direction by the guide hole 95G, the guide pedestal 91, and the restricting ribs 92A and 92B of the side frame 90. As Figure 13 , Figure 15 and Figure 17 shown, the upward movement of the restricted portion 55 is restricted by the restricting surface 93 of the side frame 90. As Figure 15 and Figure 17 shown, the sensor contact portion 57 is located at a position spaced upward from the sensor body 71 of the contact sensor 70 and can contact the sensor actuator 75 of the contact sensor 70. As Figure 13 shown, the sensor contact portion 57 is located between the guided portion 51 and the restricted portion 55 when viewed in the width direction. According to this structure, the sensor contact portion 57 located between the guided portion 51 guided by the side frame 90 and the restricted portion 55 restricted by the side frame 90 presses the sensor actuator 75. Therefore, even if the sensor contact portion 57 is pushed back by the sensor actuator 75, it is difficult for the sensor contact portion 57 to avoid upward from the sensor body 71. As a result, the signal output by the contact sensor 70 is less likely to fluctuate according to the position of the moving member 50. Therefore, the control unit C1 can more accurately detect the position of the first side guide 110 based on the signal of the contact sensor 70.

[0196] Furthermore, in this image forming apparatus 1, as Figure 13As shown, the restricted portion 55, the sensor contact portion 57, and the sensor main body 71 are located above the guided portion 51 and upstream in the feed direction DF1. The moving member 50 integrally has an intermediate portion 53 that extends upward from the guided portion 51, then extends upstream in the feed direction DF1 and is connected to the sensor contact portion 57. In the downstream of the feed direction DF1 of the guided portion, mechanism parts for feeding the sheet SH are mostly arranged, such as a motor for driving the feed portion 20 and a transmission mechanism for transmitting the driving force generated by the motor to the feed portion 20. And, when the sensor main body 71 exists at the same height as the guided portion 51, there is a concern that it is difficult to ensure the arrangement space for the signal wiring 71W routed from the sensor main body 71 to the control portion C1. Regarding this point, according to the above structure, it is easy to ensure the arrangement space for the restricted portion 55, the sensor contact portion 57, and the sensor main body 71, and it is easy to ensure the arrangement space for the signal wiring 71W routed from the sensor main body 71 to the control portion C1 below the sensor main body 71.

[0197] And, in this image forming apparatus 1, as Figures 12 to 14 shown, the compression coil spring 59 has a spiral axis X59 extending in the width direction. One end in the width direction is locked to the spring locking portion 91S of the side frame 90, and the other end in the width direction is locked to the moving member 50. The third contact surface 51T of the moving member 50 that can contact the second contact surface 115T of the first side guide 110 intersects the spiral axis X59. According to this structure, the third contact surface 51T of the moving member 50 and the second contact surface 115T of the first side guide 110 are located on the spiral axis X59 of the compression coil spring 59, so it is possible to suppress an abnormal situation such as the movement of the moving member 50 being easily distorted by the acting force of the compression coil spring 59.

[0198] Furthermore, in this image forming apparatus 1, as Figure 12 shown, the guided portion 51 has a groove 51D extending in the width direction, and the compression coil spring 59 is housed in the groove 51D. According to this structure, it is also possible not to ensure the arrangement space for the compression coil spring 59 around the guided portion 51. As a result, this image forming apparatus 1 can be suppressed from becoming large-sized.

[0199] And, in this image forming apparatus 1, as Figure 10As shown, the sheet tray 100 has: a first restricting surface 105A that restricts the upstream movement of the first rack portion 151 of the rack and pinion mechanism 150 in the feeding direction DF1; and a second restricting surface 105B that restricts the downstream movement of the first rack portion 151 in the feeding direction DF1. The third abutting surface 51T of the moving member 50 abuts against the second abutting surface 111T of the first side guide 110 between the first restricting surface 105A and the second restricting surface 105B in the feeding direction DF1. According to this structure, it is possible to suppress an adverse situation in which the operations of the first side guide 110 and the first rack portion 151 are easily distorted by the acting force of the compression coil spring 59 acting on the first side guide 110 via the moving member 50.

[0200] Further, in this image forming apparatus 1, as Figure 7 shown, the rack and pinion mechanism 150 that moves the first side guide 110 and the second side guide 120 closer to and away from each other in the width direction has a gear 153, a first rack portion 151, and a second rack portion 152. As Figure 11 shown, the second side guide 120 has: a locking claw 129Q that meshes with the sheet tray 100; and a gripping portion 129P that is operated to be displaced, thereby releasing the meshing of the locking claw 129Q with the sheet tray 100. In a state where the meshing of the locking claw 129Q with the sheet tray 100 is released, as Figure 18 (a) of FIG. shows, when the second side guide 120 and the second rack portion 152 move to the other side in the width direction, the first rack portion 151 is pressed against the gear 153 and moves toward one side in the width direction while overcoming the acting force of the compression coil spring 59. Accordingly, the first rack teeth 151G of the first rack portion 151 maintain a state of abutting against the gear 153 from one side in the width direction. As Figure 18 (b) of FIG. shows, when the second side guide 120 and the second rack portion 152 move to one side in the width direction, the first rack portion 151 moves toward the other side in the width direction in a manner following the gear 153 by the acting force of the compression coil spring 59. Accordingly, the first rack teeth 151G of the first rack portion 151 maintain a state of abutting against the gear 153 from one side in the width direction. As Figure 11As shown, even when the locking claw 129Q of the second side guide 120 is in a state of engaging with the sheet tray 100, the first rack teeth 151G of the first rack portion 151 also maintain a state of abutting against the gear 153 from one side in the width direction. That is, the tooth gap where the first rack teeth 151G engage with the gear 153 is formed such that the first side guide 110 and the first rack portion 151 can move toward one side in the width direction against the acting force of the compression coil spring 59. Thus, even when a force that presses the first side guide 110 toward one side in the width direction by the sheet SH fed from the sheet tray 100 acts, the first side guide 110 can avoid toward one side in the width direction corresponding to the amount of the tooth gap. At this time, the second side guide 120 connected to the first side guide 110 via the gear 153 can also avoid toward the other side in the width direction. As a result, it is difficult for the first side guide 110 and the second side guide 120 to generate resistance to the fed sheet SH.

[0201] Furthermore, in this image forming apparatus 1, as Figure 7 and Figure 9 shown, the abutting portion 115 separates from the guiding portion 111. That is, the abutting portion 115 has a gap between it and the guiding portion 111. Thus, as Figure 14 shown, even when a force that pushes back acts on the second abutting surface 115T of the abutting portion 115 from the third abutting surface 51T of the moving member 50 toward the other side in the width direction and the abutting portion 115 flexes, it is difficult for this force to be transmitted from the abutting portion 115 to the guiding portion 111, and it is difficult for a situation to occur where the guiding portion 111 flexes toward the other side in the width direction and the first abutting surface 111T is pressed against the sheet SH on the sheet tray 100.

[0202] Thus, even for a structure that detects the position of the first side guide 110, it is difficult for the first side guide 110 to generate resistance to the fed sheet SH. As a result, the sheet SH can be fed smoothly.

[0203] Moreover, in this image forming apparatus 1, as Figure 3 shown, the guiding portion 111 protrudes upward on the sheet tray 100 and extends along the feeding direction DF1. As Figure 7 and Figure 9As shown, the first side guide 110 has a connecting portion 116 that extends from the lower end 115D side of the abutting portion 115 toward the lower end 111D side of the guiding portion 111 and connects the abutting portion 115 and the guiding portion 111. According to this structure, even if a force that pushes back acts on the second abutting surface 115T of the abutting portion 115 from the third abutting surface 51T of the moving member 50 toward the other side in the width direction, the connecting portion 116 transmits this force from the abutting portion 115 to the lower end 111D side of the guiding portion 111, so it is difficult for this force to be transmitted from the abutting portion 115 to the guiding portion 111. As a result, it is even more difficult for the guiding portion 111 to flex toward the other side in the width direction and for the first abutting surface 111T to be pressed against the sheet SH on the sheet tray 100.

[0204] Furthermore, in this image forming apparatus 1, as Figure 14 shown, the abutting portion 115 is separated from the guiding portion 111 toward one side in the width direction. According to this structure, there is a gap in the width direction between the abutting portion 115 and the guiding portion 111. Thus, even if a force that pushes back acts on the second abutting surface 115T of the abutting portion 115 from the third abutting surface 51T of the moving member 50 toward the other side in the width direction and the abutting portion 115 flexes, interference between the abutting portion 115 and the guiding portion 111 can be suppressed.

[0205] And, in this image forming apparatus 1, as Figure 7 and Figure 9 shown, the first side guide 110 has a first reinforcing rib 117 and a second reinforcing rib 118. The first reinforcing rib 117 and the second reinforcing rib 118 are also separated from the guiding portion 111 toward one side in the width direction. The lower end side of the first reinforcing rib 117 and the lower end side of the second reinforcing rib 118 are connected to the connecting portion 116. According to this structure, even if a force that pushes back acts on the second abutting surface 115T of the abutting portion 115 from the third abutting surface 51T of the moving member 50 toward the other side in the width direction, the amount of flexure of the abutting portion 115 can be reduced by the first reinforcing rib 117 and the second reinforcing rib 118. As a result, the movement of the moving member 50 can reliably follow the position of the first side guide 110, so the signal output by the contact sensor 70 is difficult to fluctuate according to the position of the moving member 50. As a result, the control unit C1 can accurately detect the position of the first side guide 110 based on the signal of the contact sensor 70.

[0206] Furthermore, in this image forming apparatus 1, as Figure 7 and Figure 9As shown, the first side guide 110 has a sliding portion 113. The connecting portion 116 extends up to the sliding portion 113. According to this structure, even if a force that pushes back acts on the second contact surface 115T of the contact portion 115 from the third contact surface 51T of the moving member 50 toward the other side in the width direction, the connecting portion 116 transmits this force from the contact portion 115 to the lower end 111D side of the guide portion 111 and the sliding portion 113. Therefore, it is more difficult for this force to be transmitted from the contact portion 115 to the guide portion 111.

[0207] In summary, the present invention has been described with reference to the embodiments, but the present invention is not limited to the above embodiments and can be appropriately modified and applied within the scope not departing from its gist, which goes without saying.

[0208] (Modification example)

[0209] Regarding the first side guide 110 of the image forming apparatus 1 in the embodiment, a structure modified as in the Figure 19 modification example shown is also included in the present invention. In this modification example, a notch 111C is provided in a portion of the guide portion 111 that is opposite to the contact portion 115 in the width direction. In this case, even if the contact portion 115 flexes, this flexure is difficult to be transmitted to the first side guide 110, and it is easy to simplify a mold for injection molding the first side guide 110 or the like.

[0210] In the embodiment, regarding the sheet conveying apparatus of the present invention, it is specifically embodied as the image forming apparatus 1, but the present invention is not limited to this structure. For example, the structure of the present invention can also be applied to an image reading apparatus, or can be applied to a multifunction machine having an image reading apparatus provided above the image forming apparatus.

[0211] In the embodiment, the first side guide 110 and the second side guide 120 approach and separate to position the sheet SH on the sheet tray 100 in the width direction, but the present invention is not limited to this structure. For example, only the first side guide is provided on the sheet tray, and a structure in which the first side guide brings the sheet closer to position the sheet in the width direction is also included in the present invention.

[0212] In the embodiment, the sensor is the contact sensor 70, but the present invention is not limited to this structure. For example, the sensor can also be a non-contact sensor such as an optical interrupter or an inductive proximity sensor that detects the position of the moving member in a non-contact manner and outputs an on (ON) signal or an off (OFF) signal, or can be a linear encoder that numerically outputs the position of the moving member.

[0213] In the embodiment, the first direction is the up-down direction, and one side of the first direction is the upper side, but the present invention is not limited to this structure. For example, the first direction can also be the front-back direction.

Claims

1. A sheet conveying device, characterized in that, Comprising: A sheet tray on which a sheet fed in a feeding direction is placed; A first side guide that linearly moves in a width direction orthogonal to the feeding direction and positions the sheet on the sheet tray in the width direction; A moving member that linearly moves in the width direction by abutting against the first side guide; A sensor that outputs a signal corresponding to the position of the moving member; and A control unit that detects the position of the first side guide based on the signal of the sensor.

2. The sheet conveying device according to claim 1, characterized in that It comprises a frame that supports the moving member, The sensor is a contact sensor having a sensor actuator and a sensor body. The sensor actuator is displaced by abutting against the moving member, the sensor body supports the sensor actuator so as to be displaceable, and the sensor body is supported by the frame, The moving member integrally has: A guided portion that is guided by the frame to linearly move in the width direction; A restricted portion whose movement in one direction of a first direction orthogonal to the width direction is restricted by the frame; A sensor abutting portion that is located on the one side in the first direction away from the sensor body and can abut against the sensor actuator. When viewed in the width direction, the sensor abutting portion is located between the guided portion and the restricted portion.

3. The sheet conveying device according to claim 2, characterized in that The first direction is the vertical direction, The one side in the first direction is the upper side, The feeding direction intersects the vertical direction, The restricted portion, the sensor abutting portion, and the sensor body are located above the guided portion and upstream in the feeding direction, The moving member integrally has an intermediate portion that extends upward from the guided portion and then extends upstream in the feeding direction and is connected to the sensor abutting portion.

4. The sheet conveying device according to claim 2 or 3, characterized in that, Comprising: The frame that supports the moving member at a position away from the first side guide in one direction of the width direction; and A biasing spring that biases the moving member in the other direction of the width direction, The biasing spring is a compression coil spring: having a spiral axis extending in the width direction, one end in the width direction is locked to the frame, and the other end in the width direction is locked to the moving member, The moving member has an abutting surface that is located on the other side in the width direction in the guided portion and is formed at the tip of the guided portion opposite to the first side guide and can abut against the first side guide, The abutting surface intersects the spiral axis.

5. The sheet conveying device according to claim 4, characterized in that The guided portion has a groove extending in the width direction, and the compression coil spring is housed in the groove.

6. The sheet conveying device according to any one of claims 1-3, characterized in that, Comprising: A frame that supports the moving member at a position departing from the first side guide in one direction of the width direction; A biasing spring that biases the moving member in the other direction of the width direction; A second side guide that is located in the other direction of the width direction with respect to the sheet on the sheet tray; and A rack and pinion mechanism that moves the first side guide and the second side guide closer to and away from each other in the width direction, and includes a gear, a first rack portion, and a second rack portion. The gear is rotatably supported on the sheet tray between the first side guide and the second side guide in the width direction. The first rack portion has first rack teeth and moves integrally with the first side guide in the width direction. The first rack teeth have a plurality of gear teeth arranged in the width direction and mesh with the gear. The second rack portion has second rack teeth and moves integrally with the second side guide in the width direction. The second rack teeth have a plurality of gear teeth arranged in the width direction and mesh with the gear on the side opposite to the first rack portion. The sheet tray has a first restricting surface and a second restricting surface. The first restricting surface restricts the upstream movement of the first rack portion in the feeding direction, and the second restricting surface restricts the downstream movement of the first rack portion in the feeding direction. The moving member abuts against the first side guide between the first restricting surface and the second restricting surface in the feeding direction.

7. The sheet conveying device according to any one of claims 1 to 3, characterized in that Comprising: A frame that supports the moving member at a position departing from the first side guide in one direction of the width direction; A biasing spring that biases the moving member in the other direction of the width direction; A second side guide that is located in the other direction of the width direction with respect to the sheet on the sheet tray; and A rack and pinion mechanism that moves the first side guide and the second side guide closer to and away from each other in the width direction, and includes a gear, a first rack portion, and a second rack portion. The gear is rotatably supported on the sheet tray between the first side guide and the second side guide in the width direction. The first rack portion has first rack teeth and moves integrally with the first side guide in the width direction. The first rack teeth have a plurality of gear teeth arranged in the width direction and mesh with the gear. The second rack portion has second rack teeth and moves integrally with the second side guide in the width direction. The second rack teeth have a plurality of gear teeth arranged in the width direction and mesh with the gear on the side opposite to the first rack portion. The second side guide has a locking claw and a grasping portion. The locking claw meshes with the sheet tray, and the grasping portion is displaced by being operated to release the engagement between the locking claw and the sheet tray.

8. The sheet conveying device according to any one of claims 1 to 3, wherein The first side guide integrally has: A guiding portion that has a first abutting surface that abuts against a sheet on the sheet tray from one side in the width direction and guides the sheet; and An abutting portion that has a second abutting surface and is separated from the guiding portion. The second abutting surface is located on the one side in the width direction relative to the first abutting surface and abuts against the moving member from the other side in the width direction.

9. The sheet conveying device according to claim 8, wherein the guiding portion protrudes upward on the sheet tray and extends along the feeding direction, the first side guide has a connecting portion that extends from the lower end side of the abutting portion toward the lower end side of the guiding portion and connects the abutting portion and the guiding portion.

10. The sheet conveying device according to claim 9, wherein the abutting portion is separated from the guiding portion toward the one side in the width direction.

11. The sheet conveying device according to claim 10, wherein the first side guide has a first reinforcing rib and a second reinforcing rib. The first reinforcing rib protrudes from the side edge located upstream in the feeding direction in the abutting portion toward the other side in the width direction and extends in the vertical direction. The second reinforcing rib protrudes from the side edge located downstream in the feeding direction in the abutting portion toward the other side in the width direction and extends in the vertical direction. the first reinforcing rib and the second reinforcing rib are also separated from the guiding portion toward the one side in the width direction, the lower end side of the first reinforcing rib and the lower end side of the second reinforcing rib are connected to the connecting portion.

12. The sheet conveying device according to any one of claims 9 - 11, wherein the first side guide has a sliding portion that is connected to the lower end side of the guiding portion, extends toward the other side in the width direction, and extends along the feeding direction. The sliding portion supports the sheet on the sheet tray from below. the connecting portion extends to the sliding portion.

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