Hinge mechanism, image reading apparatus, and image forming apparatus

Abstract

To stabilize a relative position between an image reading unit and an opening / closing unit.SOLUTION: The hinge mechanism (3) includes a first member (31) fixed to the image reading unit, a rotation portion (30) configured to rotate about a first axis with respect to the first member (31), and an opening / closing unit fixed to the hinge mechanism (3), the image reading device includes a second member (34) turnable around a second shaft (37) with respect to a turning part (30), a torque imparting part imparting a torque in an opening direction of the opening / closing unit according to a turning angle of the opening / closing unit with respect to the image reading unit, a biasing part (71) biasing the second member (34) with respect to the turning part (30) so that the first abutting part and the second abutting part abut on the image reading unit in a state where the opening / closing unit is closed with respect to the image reading unit, and a regulating part (80) regulating movement of the second member (34) with respect to the turning part (30) in a direction parallel to a second shaft (37) of the second member (34) with respect to the turning part (30).SELECTED DRAWING: Figure 10

Description

[Technical Field]

[0001] The present invention relates to a hinge mechanism that supports an opening / closing unit to an image reading unit so that the opening / closing unit can be opened and closed, an image reading device, and an image forming apparatus. [Background technology]

[0002] For example, some image forming devices, such as copiers and multifunction peripherals, are equipped with an image reading device that reads a document. Some of these image reading devices are also equipped with an automatic document feeder (hereinafter referred to as an ADF) that automatically transports a document to a reading position (so-called flow reading glass) of a reading unit of the image reading device. When transporting a document from the ADF to the flow reading glass in this manner, a transport space must be formed between the ADF and the flow reading glass to allow the document to pass through. For this reason, the ADF is generally provided with a pair of abutment portions (butting portions) that protrude downward in the width direction of the document, and is configured to form the transport space by abutting these abutment portions against the reading unit.

[0003] However, if one of the pair of contact parts becomes loose due to deformation of the ADF over time, for example, the transport space cannot be secured accurately, and the image on the document cannot be read accurately. For this reason, a device has been proposed that automatically biases the pair of contact parts against the scanning glass to prevent the loosening even if the ADF is deformed, without adjusting the hinge mechanism, etc. (See Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2024-8606 Summary of the Invention [Problem to be solved by the invention]

[0005] The device disclosed in Patent Document 1 includes a lift shaft (37) parallel to the hinge rotation shaft (35) for rotating the ADF and a second rotation member (34) that rotates around the lift shaft in order to automatically bias a pair of contact portions toward the scanning glass and prevent the ADF from floating. However, this increases the number of parts for the shaft and the rotation member, and the structure in which multiple rotation members are nested easily makes it easier for play to occur due to component tolerances in the axial direction, making the relative position between the ADF and the reading unit unstable when the ADF is closed. Furthermore, if the relative position between the ADF and the reading unit is unstable, this can affect the image reading accuracy of the image reading device.

[0006] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a hinge mechanism, an image reading device, and an image forming apparatus that are capable of stabilizing the relative position between an image reading unit and an opening / closing unit. [Means for solving the problem]

[0007] One aspect of the present invention is used in an image reading device including an image reading unit that reads an image of a document through a light-transmitting member that transmits light, and an opening / closing unit having a first contact portion that contacts the image reading unit, and a second contact portion that is arranged at a position closer to the hinge mechanism than the first contact portion in a width direction perpendicular to a document transport direction and contacts the image reading unit, wherein the hinge mechanism supports the opening / closing unit so that the opening / closing unit can be opened and closed relative to the image reading unit, and the hinge mechanism includes a first member fixed to the image reading unit, a first shaft supported by the first member, a rotating portion that rotates relative to the first member around the first shaft, and a second shaft that is arranged at a position different from the first shaft and parallel to the first shaft and supported by the rotating portion a second member to which the opening / closing unit is fixed and which is rotatable relative to the rotating part around the second axis; a torque applying part which applies torque in a direction to open the opening / closing unit depending on the rotation angle of the opening / closing unit relative to the image reading unit; a biasing part which is interposed between the rotating part and the second member and which biases the second member relative to the rotating part so that the first abutment part and the second abutment part abut against the image reading unit when the opening / closing unit is closed relative to the image reading unit; and a regulating part which allows the second member to rotate relative to the rotating part while regulating movement of the second member relative to the rotating part in a direction parallel to the second axis. [Effects of the Invention]

[0008] According to the present invention, the relative position between the image reading unit and the opening / closing unit can be stabilized. [Brief explanation of the drawings]

[0009] [Figure 1] 1A is a schematic diagram illustrating the overall printer according to the present embodiment, and FIG. 1B is a schematic diagram illustrating an image forming engine. [Figure 2] 1 is a perspective view showing an image reading device according to an embodiment of the present invention with the ADF open. [Figure 3] FIG. 2 is a side view showing the hinge mechanism in the open state of the ADF according to the embodiment. [Figure 4] FIG. 2 is an exploded perspective view showing the hinge mechanism according to the embodiment. [Figure 5] FIG. 2 is a perspective view showing a hinge mechanism according to the embodiment. [Figure 6] FIG. 2 is a side view showing the hinge mechanism in the closed state of the ADF according to the embodiment. [Figure 7] FIG. 2 is a perspective view showing a state in which the hinge mechanism according to the embodiment is attached to a frame of the ADF. [Figure 8] 10A and 10B are diagrams illustrating the relationship between the opening and closing angle and the moment and torque of the hinge mechanism according to the present embodiment. [Figure 9] (a) is a schematic side view showing the ADF in a closed state without being bent, (b) is a schematic side view showing the ADF in a bent state with the front abutment portion abutting against the image reading unit, and (c) is a schematic side view showing the ADF in a bent state with the front and rear abutment portions abutting against the image reading unit. [Figure 10] 1A is a perspective view showing the hinge mechanism as viewed from behind, FIG. 1B is a perspective view showing the hinge mechanism with the collar member and collar screw disassembled, and FIG. 1C is an enlarged perspective view showing the collar member and collar screw disassembled. [Figure 11] FIG. 4 is a side view showing the hinge mechanism when the ADF is open. DETAILED DESCRIPTION OF THE INVENTION

[0010] [Schematic configuration of image forming device] This embodiment will be described below with reference to the drawings. First, the general configuration of a printer 100 as an image forming apparatus according to this embodiment will be described with reference to Figs. 1(a) and 1(b). Fig. 1(a) is a general view showing the printer according to this embodiment. Fig. 1(b) is a schematic view showing an image forming engine.

[0011] The printer 100 according to this embodiment is an electrophotographic laser beam printer. As shown in Fig. 1(a), the printer 100 includes a printer main body 100A and an image reading device 10 attached to the top of the printer main body 100A. In the following, the term "sheet" refers to plain paper as well as special paper such as cardboard and coated paper, recording materials of special shapes such as envelopes and index paper, and plastic film or cloth for overhead projectors. A manuscript is also an example of a sheet.

[0012] The printer main body 100A has an image forming engine 60 therein as an image forming section. As shown in FIG. 1(b), the image forming engine 60 includes an image forming unit PU as an electrophotographic image forming means and a fixing device 67. When a command to start an image forming operation is received, a photosensitive drum 61, which is a photosensitive member, rotates, and the drum surface is uniformly charged by a charging device 62. Then, an exposure device 63 modulates and outputs laser light based on image data transmitted from the image reading device 10 as an image reading means or an external computer, and scans the surface of the photosensitive drum 61 to form an electrostatic latent image. This electrostatic latent image is visualized (developed) into a toner image by toner supplied from a developing device 64.

[0013] In parallel with this image forming operation, a feeding operation is performed to feed sheets loaded on a cassette or manual feed tray (not shown) toward the image forming engine 60. The fed sheets are transported in accordance with the progress of the image forming operation by the image forming unit PU. The toner image carried on the photosensitive drum 61 is then transferred onto the sheet by a transfer roller 65. Any toner remaining on the photosensitive drum 61 after the toner image has been transferred is collected by a cleaning device 66. The sheet onto which the unfixed toner image has been transferred is passed to a fixing device 67, where it is sandwiched between a pair of rollers and heated and pressurized. The sheet onto which the toner has melted and adhered to the sheet and the image has been fixed is discharged by a discharge means such as a pair of discharge rollers.

[0014] [Image reader] Next, the image reading device 10 will be described in detail. As shown in FIG. 1(a), the image reading device 10 includes an ADF (automatic document feeder) 20 that feeds documents loaded on a document tray 121 and discharges them onto a discharge tray 122, and an image reading unit 40 that reads the documents transported by the ADF 20. That is, the ADF 20 transports sheets as documents to the image reading unit 40. The image reading unit 40 has a reading section 130 that reads an image on the surface of the document. As will be described in detail later, the ADF 20 is rotatably supported with respect to the image reading unit 40 by a hinge mechanism 3 (see FIG. 3) so that a platen glass 201 and a document table glass 203, which are light-transmitting members, can be opened. That is, the ADF 20 constitutes an opening / closing unit, and is supported by a hinge mechanism 3 so as to be openable and closable relative to an upper surface 40S of the image reading unit 40 on which a platen glass 201 and a document table glass 203 are arranged. Note that the document, which is an example of a sheet, may be blank or may have an image formed on one or both sides.

[0015] The ADF 20 has a pickup roller 101, a separation roller pair consisting of a separation drive roller 102 and a separation driven roller 103, a registration roller pair 104, conveyance roller pairs 105, 106, and 108, and a discharge roller pair 109. The ADF 20 also has a reading unit 129 for reading the image on the back side of the document.

[0016] On the other hand, the image reading unit 40 has a platen glass 201, a jump table 202, a document table glass 203, and a reading section 130 for reading the surface of a document.

[0017] The image reading device 10 can read images from documents in a flow reading mode in which the document images are scanned while the documents loaded on the document tray 121 are fed by the ADF 20, and in a fixed reading mode in which the document placed on the document glass platen 203 is scanned. The flow reading mode is selected when a document presence / absence detection sensor (not shown) detects the documents loaded on the document tray 121, or when the user explicitly instructs it via an operation panel or the like of the printer main body 100A.

[0018] When the skimming mode is executed, the pickup roller 101 descends and comes into contact with the topmost document set on the document tray 121. The documents are then fed by the pickup roller 101 and separated one by one at a separation nip formed as a separation means by the separation drive roller 102 and the separation driven roller 103. A torque limiter is disposed in the rotation support structure of the separation driven roller 103, so that the separation driven roller 103 rotates together with the separation drive roller 102 when one document is fed, and does not rotate when two or more documents are fed. This allows the documents to be separated one by one. Note that a drive force may be input to the separation driven roller 103 in the direction opposite to the sheet feeding direction.

[0019] The leading edge of the transported document strikes the stationary registration roller pair 104, and the skew of the document is corrected. The document, whose skew has been corrected, is transported by the registration roller pair 104, and is transported by transport roller pairs 105, 106, and 108 so as to pass over the surface of the platen glass 201, and then is transported so as to pass through the reading position of the reading unit 129. A platen guide 107 is disposed opposite the platen glass 201, and the platen guide 107 guides the document passing over the platen glass 201 so as to prevent it from lifting off the platen glass 201.

[0020] An image on the front side of the document is read by reading unit 130 through platen glass 201, and an image on the back side of the document is read by reading unit 129. Image information photoelectrically converted by light-receiving elements of line sensors (not shown) in reading units 130 and 129 is transferred to control unit 100C (see FIG. 1(a)). Then, the document that has passed through platen glass 201 is guided by jump platform 202 to pair of conveying rollers 108, passes through reading unit 129, and is discharged onto discharge tray 122 by pair of discharge rollers 109.

[0021] On the other hand, the fixed reading mode is selected when the device detects an original placed on the platen glass 203 or when the user explicitly instructs this via an operation panel or the like of the printer main body 100A. In this case, the original on the platen glass 203 does not move, and the reading unit 130 moves along the platen glass 203 to scan the original. Similarly, image information photoelectrically converted by a light receiving element of a line sensor (not shown) of the reading unit 130 is transferred to the control unit 100C (see FIG. 1(a)).

[0022] [Positional relationship between the ADF and image scanning unit] Next, the arrangement of the hinge mechanism 3 and the configuration of the abutment portion 21 and pressure plate 22, which are provided on the ADF 20 and serve as abutment portions that come into contact with the image reading unit 40 when the ADF 20 is closed, will be described with reference to Fig. 2. Fig. 2 is a perspective view showing the image reading device according to this embodiment with the ADF open.

[0023] As shown in FIG. 2, in the printer 10 according to this embodiment, left and right hinge mechanisms 3L, 3R (hereinafter, simply referred to as "hinge mechanism 3" when no distinction is necessary) are installed on the image reading unit 40, and support the ADF 20 on its top surface 40S so that it can be opened and closed. These left and right hinge mechanisms 3L, 3R are installed on the image reading unit 40 at two different positions in the X direction, which is the left-right direction of the printer 100. Note that these left and right hinge mechanisms 3L, 3R are designed to be different sizes according to the difference in weight of the ADF 20 in the left-right direction. Note that in this embodiment, the hinge mechanism 3 (see FIG. 3, etc.), which will be described in detail later, is configured assuming the left hinge mechanism 3L, but may also be used for the hinge mechanism 3R.

[0024] The abutment portion 21 has an abutment portion 21a as a first abutment portion that abuts against the front end of the platen glass 201 in the Y direction, which is the front-to-rear direction of the printer 100, when the ADF 20 is closed. The abutment portion 21 also has an abutment portion 21b as a second abutment portion that abuts against the rear end of the platen glass 201 in the Y direction, which is the front-to-rear direction of the printer 100, when the ADF 20 is closed. In other words, the abutment portions 21a and 21b are configured to be able to abut against the top surface 40S of the image reading unit 40.

[0025] The abutment portion 21a is disposed at a position farther from the hinge mechanism 3 than the region of the conveyance path through which the sheet is conveyed in the width direction perpendicular to the sheet conveyance direction. On the other hand, the abutment portion 21b is disposed at a position closer to the hinge mechanism 3 than the region of the conveyance path through which the sheet is conveyed in the width direction. When the abutment portions 21a and 21b come into contact with both ends of the platen glass 201, a conveyance path through which the document passes is formed between the platen glass 201 and the jump platform 202 (see FIG. 1(a)) and the platen guide 107 in the above-described flow reading mode.

[0026] That is, the platen glass 201 and jump base 202 are configured as part of a transport guide that guides the document, together with the platen guide 107 of the ADF 20. However, while other transport guides that guide the document in the ADF 20 are configured within the same ADF 20, the platen glass 201 and jump base 202 are components of the image reading unit 40. Therefore, by abutting these abutment portions 21a and 21b at both ends of the platen glass 201, the relative positions of the image reading unit 40 and the ADF 20 are appropriately maintained, and consistency is maintained between the transport path in other parts of the ADF 20 and the transport path on the platen glass 201.

[0027] Note that these abutting portions 21a and 21b may be located on the upper surface 40S of the image reading unit 40 and abut against a frame portion that surrounds the periphery of the platen glass 201. These abutting portions 21a and 21b may abut against the frame portion due to the influence of component tolerances or due to balancing adjustments (hereinafter referred to as "equalization"), which will be described in detail later. However, the surface of the frame portion is formed to be substantially flush with the surface of the platen glass 201, and even if the abutting portions 21a and 21b abut against the frame portion, this is synonymous with abutting against the surface of the platen glass 201. In other words, even if the abutting portions 21a and 21b abut against the frame portion, the relative positions of the image reading unit 40 and the ADF 20 are appropriately maintained, and consistency with other portions of the transport path is maintained.

[0028] The ADF 20 also includes a pressure plate 22 that is pressed against a platen glass 203 when the ADF 20 is closed. The pressure plate 22 is rectangular, having a front edge 22a that is in front of the printer 100, a rear edge 22b that is behind the printer 100, a left edge 22c that is on the left side, and a right edge 22d that is on the right side. One platen glass 203 is provided with a length size indicator 206 and a width size indicator 207 that indicate the size of the document to be set. When the ADF 20 is closed, the pressure plate 22 is positioned so that the left edge 22c does not overlap the length size indicator 206 but is as close to it as possible without a gap, and the rear edge 22b does not overlap the width size indicator 207 but is as close to it as possible without a gap. When the abutment of the abutment portion 21b is adjusted by the equalization function of the hinge mechanism 3, which will be described in detail later, the rear edge 22b is adjusted so that it is close to the width size indicator 207.

[0029] [Configuration of the hinge mechanism according to this embodiment] Next, the configuration of the hinge mechanism 3 according to this embodiment will be described with reference to FIGS. 3 to 8. FIG. 3 is a side view showing the hinge mechanism according to this embodiment when the ADF is open. FIG. 4 is an exploded perspective view showing the hinge mechanism according to this embodiment. FIG. 5 is a perspective view showing the hinge mechanism according to this embodiment. FIG. 6 is a side view showing the hinge mechanism according to this embodiment when the ADF is closed. FIG. 7 is a perspective view showing the hinge mechanism according to this embodiment attached to the frame of the ADF. FIG. 8 is a diagram showing the relationship between the moment and torque and the opening / closing angle of the hinge mechanism according to this embodiment. For convenience of explanation, the directions used to explain the structure of the hinge mechanism 3 will be the left-right direction (X direction), front-rear direction (Y direction), and up-down direction (Z direction) of the printer 100, assuming that the hinge mechanism is fixed to the printer 100.

[0030] 3, 4, 5, and 6, the hinge mechanism 3 roughly includes a fixed member 31 as a first member, a rotating unit 30, and a third rotating member 34 as a second member. The rotating unit 30 is configured to include a first rotating member 32 as a third member and a second rotating member 33 as a fourth member. The hinge mechanism 3 also includes a hinge rotating shaft 35 as a first shaft supported by the fixed member 31, a book rotating shaft 36 as a third shaft supported by the first rotating member 32, and an equalizing shaft 37 as a second shaft supported by the second rotating member 33. The hinge mechanism 3 also includes a torque applying unit 50 having a spring (not shown) that applies torque in the opening direction of the ADF 20 in accordance with the opening angle An1 of the ADF 20 relative to the image reading unit 40. The hinge mechanism 3 also has an equalizing spring 71 as a biasing portion that applies torque to the third rotating member 34 in a direction in which the abutment portion 21 and the pressure plate 22 are parallel to the surface of the platen glass 201. The equalizing spring 71 is configured as a spring known as a compression coil spring or a cylindrical coil spring (a so-called coil spring). The equalizing spring 71 applies torque (biasing force) that performs equalization with the equalizing shaft 37 as a fulcrum.

[0031] Next, a detailed configuration of the hinge mechanism 3 will be described. As shown in Fig. 4, the fixed member 31 has a bottom plate (not shown) fixed to the image reading unit 40, a pair of side plates 31d extending upward from the bottom plate, and a back plate 31e similarly extending upward from the bottom plate. That is, the fixed member 31 is formed by the bottom plate, side plates 31d, and back plate 31e in a box shape that is open at the top and front. Furthermore, through holes 31a are formed through the pair of side plates 31d, and the hinge rotation shaft 35 is inserted and supported in the through holes 31a so that its axial direction is in the left-right direction.

[0032] As described above, the rotating unit 30 has the first rotating member 32 and the second rotating member 33, as well as a book rotating shaft 36 supported by both the first rotating member 32 and the second rotating member 33, and a lift shaft 33A fixed to the second rotating member 33. The first rotating member 32 and the second rotating member 33 of the rotating unit 30 are supported by a hinge rotating shaft 35 so as to be rotatable relative to the fixed member 31. In addition, a torque is applied to the rotating unit 30 in the direction of opening the ADF 20 by the torque applying unit 50 shown in FIG. 3 biasing the lift shaft 33A.

[0033] As shown in FIG. 4, the first rotating member 32 has a top plate 32c and a pair of side plates 32d extending downward from the top plate 32c. That is, the first rotating member 32 is U-shaped so as to cover the fixed member 31 from above. The pair of side plates 32d are formed with a through-hole 32a on the rear side and a through-hole 32b on the front side. A hinge rotation shaft 35 inserted into the through-hole 31a of the fixed member 31 is fitted into the through-hole 32a so as to straddle the through-hole 32a in the left-right direction and is fixedly supported. Furthermore, the book rotation shaft 36 is inserted into the through-hole 32b and supported so that its axial direction is aligned with the left-right direction. Therefore, the book rotation shaft 36 is positioned parallel to the hinge rotation shaft 35 but at a different position. The first rotating member 32 is configured to be rotatable relative to the fixed member 31 around a center CT1 of the hinge rotation shaft 35.

[0034] As shown in Fig. 4, the second rotating member 33 has a top plate 33c as a first plate portion and a pair of side plates 33d as second side plates extending downward from the top plate 33c. In other words, the second rotating member 33 is disposed on a plane perpendicular to the book rotating shaft 36, the lift shaft 33A, and the equalizing shaft 37, and has plate-like side plates 33d that engage with the book rotating shaft 36, the lift shaft 33A, and the equalizing shaft 37. The second rotating member 33 also has a plate-like top plate 33c that is disposed on a plane perpendicular to the side plates 33d. In other words, the second rotating member 33 is formed in a U-shape so as to cover the first rotating member 32 from above.

[0035] The pair of side plates 33d are formed with through-holes 33a and through-holes 33b on the front side thereof. The book pivot shaft 36, inserted into the through-hole 32a of the first pivot member 32, is fitted and fixedly supported in the left-right direction through the through-hole 33a. Furthermore, the equalizer shaft 37 is inserted and supported in the through-hole 33b so that its axial direction is aligned with the left-right direction. Therefore, the lift shaft 33A and the equalizer shaft 37 are disposed parallel to but at different positions relative to the book pivot shaft 36. The second pivot member 33 is configured to be rotatable relative to the first pivot member 32, with the center CT2 of the book pivot shaft 36 serving as a fulcrum. The structure for supporting the equalizer spring 71 and collar member 81 on the second pivot member 33 will be described later. The second pivot member 33 configured in this manner is rotatable around the book pivot shaft 36 in the direction opposite to the rotation direction of the first pivot member 32 (clockwise in FIG. 3). When the second rotating member 33 rotates relative to the first rotating member 32, it rotates together with the third rotating member 34. As a result, when the ADF 20 is in the open state, the second rotating member 33 rotates relative to the first rotating member 32, making it possible to place the ADF 20 in a substantially horizontal state. For example, when reading a thick document such as a book, the document can be firmly pressed against the document table glass 203 by placing the ADF 20 in a substantially horizontal state.

[0036] As shown in FIG. 4 , the third rotating member 34 has a top plate 34c as a second plate portion and a pair of side plates 34d extending downward from the top plate 34c. The pair of side plates 34d are arranged facing each other. In other words, the third rotating member 34 has a pair of plate-like side plates 34d arranged on a plane perpendicular to the equalizing shaft 37 and engaging with the equalizing shaft 37, and a plate-like top plate 34c arranged on a plane perpendicular to the pair of side plates 34d. That is, the third rotating member 34 is formed in a U-shape so as to cover the second rotating member 33 from above. Therefore, the third rotating member 34 is arranged so that the top plate 34c is higher than the top plate 33c of the second rotating member 33.

[0037] Further, through holes 34a are formed in the pair of side plates 34d at the front. An equalizer shaft 37 is fitted and fixedly supported in the through hole 34a, which is located on the opposite side of the hinge rotation shaft 35 in the front-rear direction (i.e., on the front side) of the book rotation shaft 36 so as to straddle the book rotation shaft 36 in the left-right direction. In other words, the equalizer shaft 37 is supported at the tip end portion of the rotation section 30 (second rotation member 33) opposite the hinge rotation shaft 35. The third rotation member 34 is configured to be rotatable relative to the second rotation member 33, with the center CT3 of the equalizer shaft 37 serving as a fulcrum. The equalizer shaft 37 may be fixed to the side plate 34d of the third rotation member 34 by caulking, or may be rotatably supported by the side plate 34d of the third rotation member 34 and the side plate 33d of the second rotation member 33.

[0038] Additionally, a support plate portion 34g having, for example, five screw holes 34h formed therein is bent and formed integrally with the side plate 34d. As shown in Fig. 7, the frame 20F of the ADF 20 is fixed to this support plate portion 34g by threading screws 91 into the screw holes 34h. This integrates the third rotating member 34 and the ADF 20, and the ADF 20 is opened and closed by adjusting the angle of the third rotating member 34.

[0039] As shown in FIG. 4 , a first groove 34e is formed in the top plate 34c of the third rotating member 34 on the opposite side of the equalizing shaft 37 in the front-rear direction, i.e., on the rear side. Meanwhile, a screw hole 33e is formed in the top plate 33c of the second rotating member 33 at a position corresponding to the first groove 34e in the up-down direction. A first screw 72 having a threaded portion 71a penetrating the equalizing spring 71 and a head portion 72b protruding radially outward from the equalizing spring 71 is threaded into this screw hole 33e, thereby fixing the first screw 72 to the second rotating member 33. One end of the equalizing spring 71 is supported by abutting against the head portion 72b of the first screw 72, and the other end is supported by abutting against the top plate 34c around the first groove 34e of the third rotating member 34. Therefore, the equalizing spring 71 is disposed between the second rotating member 33 and the third rotating member 34. The action of the equalizing spring 71 will be described later. The restricting portion 80, which is arranged in parallel with the equalizing spring 71 in the left-right direction, will also be described in detail later.

[0040] [Applying torque in the opening and closing direction to the hinge mechanism] Next, a description will be given of the torque applying unit 50 that applies torque in the direction of opening the ADF 20 in accordance with the opening / closing angle An1 of the ADF 20 relative to the image reading unit 40. The torque applying unit 50 shown in Fig. 3 is configured with a pair of sliders (not shown) and a spring disposed between them. One of the pair of sliders is supported by the fixed member 31, and the other slider is supported by a lift shaft 33A that is disposed to penetrate the first and second rotating members 32 of the rotating unit 30.

[0041] When the first rotating member 32 opens or closes relative to the fixed member 31 as the ADF 20 opens or closes, the torque applying unit 50 rotates together with the first rotating member 32 about the center CT1 of the hinge rotating shaft 35 as a fulcrum, causing a spring (not shown) of the torque applying unit 50 to expand or contract. Here, the book rotating shaft 36 is positioned relative to the first rotating member 32 and the second rotating member 33, and the biasing force applied from the torque applying unit 50 to the lift shaft 33A fixed to the second rotating member 33 that is rotatable about the book rotating shaft 36 changes. In short, the biasing force applied from the torque applying unit 50 is applied to the rotating unit 30, which is made up of the first rotating member 32 and the second rotating member 33, and the biasing force changes depending on the rotation angle of the rotating unit 30, i.e., the opening / closing angle An1 shown in FIG. 3 .

[0042] The opening / closing angle An1 is the angle of rotation of the first rotating member 32 (rotating unit 30) relative to the fixed member 31, with the hinge rotation shaft 35 as the fulcrum. Also, Fig. 8 shows the relationship between the magnitude of the moment M in the direction in which the ADF 20 closes relative to the image reading unit 40 and the magnitude of the torque T applied by the torque application unit 50 in the opening direction, relative to this opening / closing angle An1. That is, when this opening / closing angle An1 is angle An1a (for example, 10 to 20 degrees), the torque T applied by the torque application unit 50 has a characteristic of peaking. Note that such a characteristic of the torque T is achieved by the surface shape (cam surface) of one of the sliders and a cam pin (not shown) fixed to the fixed member 31 that slides on the surface, but as this is well known, a description thereof will be omitted.

[0043] The hinge mechanism 3 is configured so that when the opening / closing angle An1 is 10 degrees or less, that is, when the ADF 20 is closed to 10 degrees or less, the moment M due to the ADF 20's own weight becomes larger than the torque T applied by the torque application unit 50 of the hinge mechanism 3, causing the ADF 20 to close under its own weight. Also, when the opening / closing angle An1 is 20 degrees or more, the torque T applied by the torque application unit 50 of the hinge mechanism 3 becomes equal to or greater than the moment M due to its own weight, allowing the ADF 20 to be maintained in an open state and making it easy to open and close the ADF 20.

[0044] [Equalization operation] Next, the equalizing operation of the hinge mechanism 3 will be described with reference to Figure 9. Figure 9(a) is a schematic side view showing a state in which the ADF is closed without being bent. Figure 9(b) is a schematic side view showing a state in which the ADF is bent and the front abutment portion abuts against the image reading unit. Figure 9(c) is a schematic side view showing a state in which the ADF is bent and the front and rear abutment portions abut against the image reading unit.

[0045] In the above-described flow-through mode, the document being transported is exposed toward the platen glass 201 in an area of ​​the platen guide 107 of the ADF 20 that corresponds to the platen glass 201 (see FIG. 2). Abutment sections 21a and 21b are arranged on both sides of the platen guide 107 in the width direction (front-rear direction), and are formed to the same height so as to form a transport path between the platen guide 107 and the ADF 20. The abutment sections 21a and 21b are arranged so as to come into contact with the platen glass 201 (or its periphery) when the ADF 20 is closed relative to the image reading unit 40. In other words, by having both abutment sections 21a and 21b come into contact with the upper surface 40S of the image reading unit 40, it is possible to properly maintain (parallel) the relative positions of the platen guide 107 of the ADF 20 and the upper surface 40S of the image reading unit 40.

[0046] As shown in FIG. 9(a), if the ADF 20 has high rigidity and the relative dimensions of the abutment portions 21a and 22b and the top surface 40S of the image reading unit 40 are aligned, both abutment portions 21a and 21b will contact the top surface 40S when the ADF 20 is closed. Recently, ADFs 20 with frames 20F made of resin or other materials for weight reduction have lower rigidity than those made of metal frames. In such ADFs, the frame is prone to deformation over time, particularly due to the continuous upward lifting force Ft exerted by the torque of the torque application portion 50. As shown in FIG. 9(b), the ADF 20 sags downward due to its own weight W (hereinafter referred to as "front sagging") in front of the center of gravity, so the abutment portion 21a on the front side contacts the top surface 40S first. In other words, as deformation progresses over time, the abutment portion 21b on the back side tends to float above the top surface 40S. However, in the hinge mechanism 3 of this embodiment, the biasing force of the equalizing spring 71 biases the equalizing shaft 37 clockwise in the figure. This moves the rear abutment portion 21b downward (in the -Z direction) to equalize the abutment portions 21a and 21b, and as shown in FIG. 9(c), that is, even if the frame of the ADF 20 is deformed, the abutment portions 21a and 21b can be brought into contact with the upper surface 40S.

[0047] [Conditions for equalization to occur] (Conditions for abutting the rear abutting portion 21b) To achieve the above-described equalizing operation, a relationship must be established between the lifting force Ft of the torque applying portion 50 and the moment around the equalizing shaft 37 (i.e., the biasing force of the equalizing spring 71). First, the conditions for the rear abutment portion 21b to come into contact with the upper surface 40S of the image reading unit 40 will be described.

[0048] As shown in FIG. 9(b), in this state, the ADF 20 has its own weight W at a distance y from the abutting portion 21a on the front side. w1, a moment acts in the direction of closing the ADF 20. In addition, a lifting force Ft in the direction of opening the ADF 20 is applied to the equalizer shaft 37 by the torque application portion 50 of the hinge mechanism 3. The equalizer shaft 37 is located at a distance y from the abutment portion 21a on the front side. t1 Furthermore, the equalizing force Fs that presses the third rotating member 34 toward the second rotating member 33 is applied by the equalizing spring 71 to the position at a distance y from the abutting portion 21a on the front side. s1 It acts at the position.

[0049] Here, the condition under which the sum of the equalizing force Fs by the equalizing spring 71 and the moment due to the weight W of the ADF 20 is greater than the moment due to the lifting force Ft by the torque applying portion 50 of the hinge mechanism 3 is given by the following formula (1). Fs·y s1 >Ft·y t1 -W·y w1 ···(1)

[0050] That is, when the relationship of formula (1) is established, the equalizing shaft 37, on which the torque T (see FIG. 8) described above is acting, can be pressed down to close the rotating part 30. In other words, as shown in FIG. 9(c), the rear abutment part 21b of the ADF 20 can be lowered toward the upper surface 40S of the image reading unit 40. From formula (1), the biasing force of the torque applying part 50 can be set so that the operating force when lifting the front of the ADF 20 relative to the weight W of the ADF 20 is within a predetermined force, and the equalizing force can be set to be greater than or equal to the difference in moment due to each factor.

[0051] (Conditions for causing the front abutment portion 21a to abut) On the other hand, if the equalizing force Fs is set strong simply to satisfy the above formula (1), the equalizing force Fs will cause the abutment portion 21a on the front side of the ADF 20 to float, especially when the ADF 20 is not deformed as shown in Figure 9(a). That is, assume that both abutment portions 21a and 21b are in contact with the top surface 40S when the frame of the ADF 20 is not yet deformed as shown in Figure 9(a). In this case, the equalizing spring 71 is compressed more (because the spring length is shorter) than when the frame of the ADF 20 is deformed more (see Figure 9(c)), and therefore the equalizing force Fs becomes stronger.

[0052] In this state, the rear abutment portion 21b of the ADF 20 contacts the top surface 40S and serves as a fulcrum. Therefore, the moment due to the weight W of the ADF 20 and the lifting force Ft by the torque application portion 50 of the hinge mechanism 3 have clockwise components in the figure (forces that bring the front abutment portion 21a into contact with the top surface 40S). Conversely, the moment due to the equalizing force Fs0 has counterclockwise components (forces that lift the front abutment portion 21a). Therefore, the condition for bringing the front abutment portion 21a into contact with the top surface 40S is expressed by the following equation (2). Fs0 y s2 >Ft·y t2 +W·y w2 ···(2)

[0053] As described above, the lower and upper limits of the equalizing force Fs are defined for when the deformation of the frame of the ADF 20 has progressed and the equalization amount becomes large, and when the deformation of the frame of the ADF 20 has not progressed and not much equalization amount is required. In other words, by designing the biasing force of the equalizing spring 71 to be between the lower and upper limits of the equalizing force Fs, the equalizing operation can be performed normally whether the frame of the ADF 20 is new or has deteriorated over time.

[0054] [About the X-direction play of the third rotating member] Next, a case where backlash occurs in the third rotating member 34 in the X direction will be described. For example, in a hinge mechanism without an equalizing function, there is no equalizing shaft 37 or third rotating member 34, and only the rotating unit 30 rotates relative to the fixed member 31. Specifically, in this case, the members that rotate relative to the fixed member 31 are two rotating members: the first rotating member 32 via the hinge rotating shaft 35, and the second rotating member 33 via the book rotating shaft 36. In this case, for example, in a structure in which the ADF 20 is fixed to the second rotating member 33, even if backlash occurs in the axial direction (i.e., the X direction) of the second rotating member 33 relative to the fixed member 31 due to component tolerances, the positional deviation relative to the reading unit 130 is within the allowable range.

[0055] However, in the hinge mechanism 3 according to this embodiment, as described above, the frame 20F of the ADF 20 is fixed to the third rotating member 34, i.e., the third rotating member 34 and the ADF 20 are integrated. The third rotating member 34 is rotatably supported relative to the second rotating member 33 via the equalizer shaft 37. Therefore, play in the X direction (i.e., the axial direction of each axis) of the third rotating member 34 relative to the fixed member 31 caused by component tolerances occurs among three rotating members, and is therefore larger than in the case of two rotating members. Therefore, individual differences in the hinge mechanism 3 can cause the positional deviation of the ADF 20 relative to the reading unit 130 to exceed the allowable range, potentially affecting the accuracy of image reading of documents transported by the ADF 20. Therefore, the hinge mechanism 3 according to this embodiment solves this problem by adopting the configuration described below.

[0056] [Details of the Regulation Department] Next, the restricting portion 80 of the hinge mechanism 3 according to this embodiment will be described with reference to Fig. 10. Fig. 10(a) is a perspective view showing the hinge mechanism as viewed from behind. Fig. 10(b) is a perspective view showing the hinge mechanism with the collar member and collar screw disassembled. Fig. 10(c) is an enlarged perspective view showing the collar member and collar screw disassembled.

[0057] 10(a) and 10(b), the restricting portion 80, which restricts movement of the third rotating member 34 relative to the second rotating member 33 in the X direction to position the third rotating member 34, is disposed at the rear end of the second rotating member 33 and the third rotating member 34. In other words, the restricting portion 80 restricts movement in a direction parallel to the equalizing axis 37, that is, in a direction parallel to the YZ plane as a first plane direction perpendicular to the equalizing axis 37.

[0058] Specifically, the top plate 33c serving as the first plate portion of the second rotating member 33 is disposed perpendicular to the YZ plane and faces the XY plane serving as the second surface direction parallel to the axial direction of the equalizing shaft 37. The top plate 34c serving as the second plate portion of the third rotating member 34 is disposed so as to cover at least a portion of the top plate 33c of the second rotating member 33, specifically, so as to cover most of the remaining portions but not the screw holes 33e and 33f. In the present hinge mechanism 3, the equalizing shaft 37 is disposed at one end of the second rotating member 33 and the third rotating member 34 in the front-rear direction (Y direction), and the restricting portion 80 is disposed at the other end. In the present hinge mechanism 3, the restricting portion 80 is disposed so as to extend in a direction perpendicular to the top plate 33c in parallel with the above-described equalizing spring 71 and screw 72. By arranging the restricting portion 80 and the equalizing spring 71 in parallel in this manner, the arrangement space can be made more compact than if they were arranged in completely separate locations, and the structure of the ADF 20, which covers the upper part of the hinge mechanism 3, can also be simplified.

[0059] The restricting portion 80 is configured to include a screw hole 33f of the second rotating member 33, a collar member 81 as a guide portion or cylindrical member, a screw 82 as a guide portion, and a second groove 34f of the third rotating member 34 as a guided portion or groove. As shown in Fig. 10(c), the collar member 81 is hollow with a through hole 81a formed therein and is formed in a cylindrical shape with an outer circumferential surface 31b. On the other hand, the screw 82 is configured to include a shaft portion 82a with a male thread formed therein and a head portion 82b as a protruding portion whose diameter is enlarged so as to protrude radially outward beyond the shaft portion 82a.

[0060] A shaft portion 82a of the screw 82, which has a diameter R1, is passed through a through-hole 81a of the collar member 81, which has a diameter R2 that is approximately the same length as the diameter R1, and the male thread of the shaft portion 82a is screwed into the female thread of the screw hole 33f. This fixes the screw 82 integrally with the second rotation member 33. This positions the collar member 81 so that it cannot move in the surface direction of the top plate 33c of the second rotation member 33 (in the X and Y directions when the ADF 20 is closed).

[0061] The collar member 81 is disposed such that its outer peripheral surface 81b, having a diameter R3, fits into the second groove 34f of the third rotating member 34, which has a width R4 that is approximately the same length as the diameter R3. Therefore, the X-direction end (i.e., the vertex in the left-right direction) of the outer peripheral surface 81b of the collar member 81 forms a sliding portion 81SL extending in the YZ plane. When the third rotating member 34 rotates relative to the second rotating member 33 around the equalizing shaft 37 as a fulcrum, the second groove 34f, serving as a guided member, slides on the sliding portion 81SL of the outer peripheral surface 81b. In other words, the second groove 34f is a groove formed to slide while sandwiching the outer peripheral surface 81b. This allows the third rotating member 34 (i.e., the ADF 20) to be restricted from moving in the X direction relative to the second rotating member 33, even if there is play between the second rotating member 33 and the third rotating member 34. Therefore, when the ADF 20 is closed, the relative position between the ADF 20 and the image reading unit 40 can be stabilized, and the accuracy of reading the image of the document conveyed by the ADF 20 can be improved.

[0062] Furthermore, for example, in order to restrict movement of the third rotating member 34 in the X direction relative to the second rotating member 33, it is possible to adopt a configuration in which the side plate 33d of the second rotating member 33 comes into contact with the side plate 34d of the third rotating member 34. However, if the side plate 33d of the second rotating member 33 comes into contact with the side plate 34d of the third rotating member 34 in this manner, there is a risk that abnormal noise such as a contact sound will be generated when the third rotating member 34 is rotated about the equalizing shaft 37 as a fulcrum. In the present hinge mechanism 3, the movement of the third rotating member 34 in the X direction relative to the second rotating member 33 is restricted only by the sliding of the sliding portion 81SL of the collar member 81 with the second groove 34f, thereby preventing the generation of such abnormal noise.

[0063] Furthermore, the equalizing shaft 37 is disposed at one end of the third rotating member 34 in the Y direction, and the restricting unit 80 is disposed at the other end of the third rotating member 34. For this reason, the other end of the third rotating member 34 swings in the X direction with the equalizing shaft 37 as a fulcrum, increasing the amount of movement, which may result in the ADF 20 on the opposite side of the equalizing shaft 37 also swinging, increasing the amount of movement. However, because the restricting unit 80 is disposed at the other end of the third rotating member 34, the amount of movement can be suppressed and reduced, thereby improving the positional accuracy of the third rotating member 34 (i.e., the ADF 20) in the X direction.

[0064] [Restriction of rotation range of third rotating member] Next, the restriction of the rotation range of the third rotation member 34 relative to the second rotation member 33 by the head 82b of the screw 82 will be described with reference to Fig. 11. Fig. 11 is a side view showing the hinge mechanism when the ADF is open.

[0065] 11 , when the operator opens the ADF 20 from the top surface 40S of the image reading unit 40, the weight of the ADF 20 acts around the equalizer shaft 37 in the direction A (clockwise in the figure), compressing the equalizer spring 71. At this time, the head 82b of the screw 82 of the restricting portion 80 forms a protrusion that protrudes radially outward beyond the diameter R3 of the outer circumferential surface 81b of the collar member 81, i.e., is formed wider than the width R4 of the second groove 34f of the third rotating member 34. Therefore, the head 82b of the screw 82 abuts against the top plate 34c around the second groove 34f of the third rotating member 34, restricting the third rotating member 34 from rotating further relative to the second rotating member 33. In this way, the rotation range of the third rotation member 34 relative to the second rotation member 33 is restricted, so when the ADF 20 is opened, the weight of the ADF 20 prevents the third rotation member 34 from tipping in the A direction relative to the second rotation member 33. Therefore, the presence of the screw 82 of the restriction unit 80 stabilizes the movement of the ADF 20 when opening and closing the ADF 20 (particularly when closing the ADF 20), improving operability. Therefore, the restriction unit 80 in this embodiment has two functions: a function to improve the positional accuracy of the ADF 20 in the X direction as described above, and a function to stabilize the movement of the ADF 20.

[0066] [Possibilities for other embodiments] In the present embodiment described above, the restricting portion 80 is disposed at the end of the third rotating member 34 on the opposite side in the Y direction from the equalizing shaft 37. However, the present invention is not limited to this, and the restricting portion 80 may be disposed at any position, such as between the side plate 33d and the side plate 34d, as long as the position can restrict movement of the third rotating member 34 in the X direction relative to the rotating portion 30 (second rotating member 33).

[0067] Furthermore, in this embodiment, the restricting portion 80 has been described as restricting movement of the third rotating member 34 in the X direction relative to the second rotating member 33. However, this is not limiting, and it may also be restricting movement of the third rotating member 34 in the X direction relative to the fixed member 31 or the first rotating member 32, for example. In this case, it is conceivable to provide a slot or groove in the top plate of each rotating member and arrange it so that a collar member or a screw can pass through it.

[0068] In addition, in this embodiment, a collar member is used as the guiding portion, and the second groove 34f is used as the guided portion. However, this is not limiting. For example, a long hole or a slit may be provided in the top plate 34c as the guided portion, and the guided portion may slide along the guide portion. Furthermore, for example, two parallel plates extending in the YZ plane may be provided in the top plate 34c as the guided portion, and the guided portion may slide along the guide portion. Furthermore, for example, a spacer fixed to the side plate 33d may be provided as the guiding portion, and the side plate 34d may slide along the YZ plane as the guided portion. In short, any structure may be used as long as it restricts the movement of the third rotating member 34 in the X direction.

[0069] Furthermore, in the present embodiment, the head 82b of the screw 82 is described as restricting the rotation range of the third rotation member 34 when the ADF 20 is open relative to the image reading unit 40. However, the present invention is not limited to this, and the rotation range of the third rotation member 34 may be restricted by any structure, such as by providing another screw.

[0070] In the present embodiment, the rotating section 30 has been described as having a first rotating member 32, a second rotating member 33, and a book rotating shaft 36. That is, when a thick document such as a book is placed on the upper surface 40S of the image reading unit 40 and sandwiched by the ADF 20, the second rotating member rotates around the book rotating shaft relative to the first rotating member, and the ADF 20 can be closed in a state parallel to the upper surface 40S. However, the present invention is not limited to this, and the rotating section may be composed of a single member, for example.

[0071] Furthermore, in this embodiment, the biasing portion that generates the equalizing force is described as including a single equalizing spring 71. However, this is not a limitation, and multiple springs may be provided as the biasing portion that generates the equalizing force. Furthermore, the equalizing spring 71 as the biasing portion is not limited to being located above the top plate 34c of the third rotation member 34, and may be located in any position, such as outside the side plate 34d. In other words, the number and location of the springs as the biasing portion that generates the equalizing force are not limited as long as they are located so as to generate a biasing force around the axis of the equalizing shaft 37. [Explanation of symbols]

[0072] 3...hinge mechanism / 10...image reading device / 20...ADF (opening / closing unit, automatic document feeder) / 21a...butting portion (first contact portion) / 21b...butting portion (second contact portion) / 20F...frame / 30...rotating portion / 31...fixed member (first member) / 32...first rotating member (third member) / 33...second rotating member (fourth member) / 33c...top plate (first plate portion) / 34...third rotating member (second member) / 34c...top plate (second plate portion) / 34f...second groove (guided portion, groove) / 3 5... Hinge rotation axis (first axis) / 36... Book rotation axis (third axis) / 37... Equalization axis (second axis) / 40... Image reading unit / 50... Torque application section / 60... Image forming engine (image forming section) / 71... Equalization spring (biasing section) / 80... Regulating section / 81SL... Sliding section / 81... Collar member (guide section, cylindrical member) / 81b... Outer periphery / 82... Screw / 82b... Head (protruding section) / 100... Printer (image forming apparatus) / 201... Platen glass (translucent member)

Claims

1. an image reading unit that reads an image of a document through a light-transmitting member that transmits light; an opening / closing unit having a first contact portion that contacts the image reading unit, and a second contact portion that is disposed at a position closer to the hinge mechanism than the first contact portion in a width direction perpendicular to a document transport direction and that contacts the image reading unit, a hinge mechanism that supports the opening / closing unit so that the opening / closing unit can be opened and closed relative to the image reading unit, a first member fixed to the image reading unit; a first shaft supported by the first member; a rotating portion that rotates around the first axis relative to the first member; a second shaft disposed parallel to the first shaft at a position different from that of the first shaft and supported by the rotating portion; a second member to which the opening / closing unit is fixed and which is rotatable relative to the rotation portion around the second axis; a torque applying unit that applies torque in a direction to open the opening / closing unit in accordance with a rotation angle of the opening / closing unit relative to the image reading unit; a biasing portion interposed between the pivoting portion and the second member and biasing the second member against the pivoting portion so that the first contact portion and the second contact portion contact the image reading unit when the opening / closing unit is closed relative to the image reading unit; a restricting portion that restricts movement of the second member relative to the rotating portion in a direction parallel to the second axis while allowing the second member to rotate relative to the rotating portion, A hinge mechanism characterized by the above.

2. The restriction portion is a guide portion provided on the rotating portion and forming a sliding portion extending in a first plane direction perpendicular to the second axis; a guided portion that is provided on the second member and that is guided in the first surface direction by sliding on the sliding portion, 2. The hinge mechanism of claim 1.

3. the second shaft is disposed at one end portion of the second member; The guided portion is disposed at the other end portion of the second member.

3. The hinge mechanism of claim 2.

4. the rotating portion has a first plate portion disposed in a second plane direction perpendicular to the first plane direction, the second member has a second plate portion arranged to cover at least a portion of the first plate portion, The guide portion is provided on the first plate portion, The guided portion is provided on the second plate portion, 3. The hinge mechanism of claim 2.

5. the guide portion includes a cylindrical member having a center disposed in the planar direction and an outer circumferential surface that forms the sliding portion, and a screw that fixes the cylindrical member to the rotating portion, The guided portion is a groove formed in the second member so as to slide while sandwiching the outer circumferential surface of the cylindrical member in the radial direction.

5. The hinge mechanism of claim 4.

6. The screw is disposed so as to penetrate the cylindrical member, one end of the screw is fixed to the rotating portion, and the other end of the screw has a protruding portion that protrudes radially outward beyond the outer circumferential surface of the cylindrical member.

6. The hinge mechanism of claim 5.

7. The biasing portion is disposed in parallel with the restricting portion so as to be interposed between the first plate portion and the second plate portion.

5. The hinge mechanism of claim 4.

8. The rotating portion is a third member that rotates relative to the first member about the first axis; a third shaft disposed parallel to the first shaft at a position different from that of the first shaft and supported by the third member; a fourth member that rotates relative to the third member about the third axis, The biasing portion is interposed between the fourth member and the second member.

2. The hinge mechanism of claim 1.

9. A device comprising the image reading unit, the opening / closing unit, and the hinge mechanism according to any one of claims 1 to 8. An image reading device characterized by:

10. the opening / closing unit is an automatic document feeder that feeds a document so that the document passes over the surface of the light-transmitting member; 10. The image reading device according to claim 9, wherein:

11. The automatic document feeder has a frame made of a resin material.

11. The image reading device according to claim 10.

12. The image reading device according to claim 9 ; an image forming unit that forms an image on a sheet, An image forming apparatus characterized by:

Images