Image reading device and image forming device

Abstract

To provide an image reading device and an image forming device that can reduce the deflection of a light-transmitting member. [Solution] The image reading device 101 comprises a reading unit 103 having a frame, a light-transmitting member 300, and a reading means 401, and a transport unit 102 configured to be openable and closable relative to the reading unit. The light-transmitting member 300 has a first contact portion 501 positioned on the first side relative to the center, and a second contact portion 502 positioned on the second side opposite the first side relative to the center W0 of the light-transmitting member. When the transport unit is closed, the first contact portion 1 and the second contact portion contact the first surface of the light-transmitting member. The reader frame comprises a first support portion 601 positioned on the first side of the first contact portion, a second support portion 602 positioned on the second side of the second contact portion, a third support portion 603 positioned within the range from the first contact portion to the second contact portion, and a fourth support portion 604 positioned within the range from the first contact portion to the second contact portion and on the second side of the third support portion 603.

Description

Technical Field

[0001] The present invention relates to an image reading device that reads image information from a sheet, and an image forming device that forms an image on a recording material.

Background Art

[0002] Patent Document 1 describes an image reading device having an image reading unit with a transparent member for rapid reading, and a conveyance unit (ADF) that can be opened and closed with respect to the image reading unit. According to this document, when the ADF is closed, the abutting portion provided on the ADF abuts against both ends of the transparent member, thereby appropriately maintaining the relative position between the image reading unit and the ADF.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When the transparent member is deflected by the load received from the abutting portion (abutting portion) on the conveyance unit side in a state where the conveyance unit is closed, there is a possibility that the image reading accuracy may decrease.

[0005] Therefore, an object of the present invention is to provide an image reading device and an image forming device capable of reducing the deflection of the transparent member.

Means for Solving the Problems

[0006] One aspect of the present invention comprises a reading unit having a frame, a light-transmitting member supported by the frame, and a reading means for reading image information from a sheet through the light-transmitting member, and a transport unit configured to be openable and closable relative to the reading unit and for transporting a sheet from which image information has been read by the reading means, wherein the transport unit has a first contact portion located on the first side relative to the center of the light-transmitting member in the sheet width direction perpendicular to the sheet transport direction, and a second contact portion located on the second side opposite to the first side relative to the center of the light-transmitting member in the sheet width direction, and wherein the first contact portion and the second contact portion contact the first surface of the light-transmitting member when the transport unit is closed. The image reading device is configured such that the frame is provided with: a first support portion positioned to the first side of the first contact portion in the sheet width direction and supporting a second surface of the light-transmitting member opposite to the first surface; a second support portion positioned to the second side of the second contact portion in the sheet width direction and supporting a second surface of the light-transmitting member; a third support portion positioned within the range from the first contact portion to the second contact portion in the sheet width direction and supporting a second surface of the light-transmitting member; and a fourth support portion positioned within the range from the first contact portion to the second contact portion in the sheet width direction and to the second side of the third support portion, and supporting a second surface of the light-transmitting member. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide an image reading device and an image forming device that can reduce the deflection of a light-transmitting member. [Brief explanation of the drawing]

[0008] [Figure 1] A schematic diagram of an image forming apparatus according to the first embodiment. [Figure 2] A schematic diagram of an image reading device according to the first embodiment. [Figure 3] A perspective view of the reading unit according to the first embodiment. [Figure 4] A perspective view showing the inside of the reading unit according to the first embodiment. [Figure 5] A perspective view of the ADF according to the first embodiment. [Figure 6] A cross-sectional view of the image reading device according to the first embodiment. [Figure 7] A view (a) of the upper frame and panning glass of the reading unit according to the first embodiment, as seen from below, and a plan view (b) showing the positional relationship between the panning glass and other elements according to the first embodiment. [Figure 8] A perspective view showing a part of the reading unit according to the first embodiment. [Figure 9] A perspective view (a) and a side view (b) of the hinge portion according to the second embodiment. [Figure 10] An exploded view of the hinge portion according to the second embodiment. [Figure 11] Diagrams (a-c) illustrating the hinge portion according to the second embodiment. [Modes for carrying out the invention]

[0009] The embodiments relating to this disclosure will be described below with reference to the drawings.

[0010] 《First Embodiment》 First, the image forming apparatus 100 and image reading apparatus 101 according to the first embodiment will be described using Figures 1 to 3. The image forming apparatus 100 according to this embodiment is an electrophotographic color copier equipped with an image forming unit 120 and an image reading apparatus 101 as image forming means. The image forming apparatus 100 can form an image on a recording material P (recording medium) based on image information read from the original by the image reading apparatus 101. A variety of sheets of different sizes and materials can be used as the recording material P and original, including paper such as plain paper and cardboard, sheet materials with surface treatment such as coated paper, specially shaped sheet materials such as envelopes and index paper, plastic film, cloth, etc.

[0011] Note that the color copier described in this embodiment is merely an example, and the "image forming apparatus" may be, for example, a facsimile apparatus or a multifunction peripheral. Further, the image forming means is not limited to an electrophotographic system, and for example, a printing mechanism using an inkjet system may be used.

[0012] As shown in FIG. 1, the image forming apparatus 100 includes a printer main body 104 which is the apparatus main body of the image forming apparatus, and an image reading apparatus 101 disposed above the printer main body 104. The printer main body 104 is provided with an image forming unit 120, a cassette 105, a fixing device 118, and the like. The image reading apparatus 101 includes a reading unit 103 (reader unit) and an automatic document feeder (ADF) 102 as a conveying unit provided above the reading unit 103.

[0013] The image forming unit 120 includes process units 111, 112, 113, 114, laser scanners 107, 108, 109, 110 as exposure means, an intermediate transfer belt 115 as an intermediate transfer member, and a secondary transfer roller 116 as transfer means. Each of the process units 111 to 114 includes a photosensitive drum as an image carrier, a charger, a developing device, a cleaning unit, etc. for performing each step of the electrophotographic process on the photosensitive drum.

[0014] (Image forming operation) The printer main body 104 is capable of executing an image forming operation which is a series of operations for forming an image while conveying the recording material P one by one. When the user presses a copy execution button in a state where a document is set in the image reading apparatus 101, for example, the control unit of the image forming apparatus 100 starts the reading operation in the image reading apparatus 101 and the image forming operation in the printer main body 104.

[0015] When the image forming operation is started, the photosensitive drums of each of the process units 111 to 114 and the intermediate transfer belt 115 are rotationally driven. Each photosensitive drum is uniformly charged on its surface by a charger. The laser scanners 107 to 110 are driven by a video signal generated based on the image information acquired by the image reading device 101, and irradiate light onto the corresponding photosensitive drum. As a result, electrostatic latent images corresponding to the yellow, magenta, cyan, and black color components are formed on the surfaces of the four photosensitive drums. This electrostatic latent image is developed by a developer (toner) supplied from the developing device to the photosensitive drum, and becomes a single-color toner image. The single-color toner images formed on each photosensitive drum are transferred from the photosensitive drum to the intermediate transfer belt 115 by applying a voltage to the primary transfer roller. At that time, the transfer is performed so that the four-color single-color toner images overlap each other, and a full-color image (hereinafter simply referred to as an image) is formed on the intermediate transfer belt 115.

[0016] In parallel with the operation of the image forming unit 120 as described above, the recording material P housed in any of the cassettes 2 is fed by the feed roller 106. The fed recording material P is obliquely corrected by the registration roller pair, and then conveyed to the secondary transfer portion formed between the intermediate transfer belt 115 and the secondary transfer roller 116. Then, by applying a voltage to the secondary transfer roller 12, the image is transferred from the intermediate transfer belt 115 to the recording material P.

[0017] The recording material P that has passed through the secondary transfer portion is sent to the fixing device 118 via the pre-fixing conveyance portion 117. The fixing device 118 fixes the recording material P by heating and pressurizing the image on the recording material P while sandwiching and conveying the recording material P at the nip portion of the fixing roller pair. The recording material P that has passed through the fixing device 118 is discharged to the outside of the printer main body 104 by the discharge unit and loaded on the discharge tray 119.

[0018] (Image Reading Device) The image reading device 101 will now be described. Figure 2 is a perspective view of the image reading device 101. Figure 3 is a perspective view of the reading unit 103. Figure 4 is a perspective view showing the inside of the reading unit 103. Figure 5 is a perspective view of the ADF 102 from below. Figure 6 is a cross-sectional view of the image reading device 101 in a virtual plane passing through the reading glass 300. Figure 7(a) is a perspective view of the upper frame 408 and reading glass 300 of the reading unit 103 from below. Figure 7(b) is a view of the reading glass 300 from below. Figure 8 is a perspective view showing an enlarged portion of the inside of the reading unit 103.

[0019] In the following description and drawings, the sheet width direction perpendicular to the document transport direction (sheet transport direction) in the ADF 102 is defined as the X direction. The vertical direction when the image forming apparatus 100 is installed on a horizontal plane is defined as the Z direction. The direction that intersects both the X and Z directions is defined as the Y direction. Preferably, the X, Y, and Z directions are perpendicular to each other. The X direction can be said to be the main scanning direction of the scanning unit 401 (reading means) provided in the reading unit 103. In addition, one side in the X direction (the direction opposite to arrow X, the lower left direction in Figure 2) is sometimes called the front or front side, and the opposite direction is sometimes called the rear or rear side.

[0020] (Reading unit) As shown in Figures 1 and 3, the reading unit 103 includes a reader frame 103A, a scanning glass 300, a document glass 301, and a scanning unit 401.

[0021] The scanning glass 300 and the document glass 301 are both examples of light-transmitting members (transmissive members) that allow light to pass through. The scanning unit 401 is an example of a reading means that reads image information from a document. The scanning unit 401 converts the optical image obtained by optically scanning the document through the scanning glass 300 or the document glass 301 into an electrical signal by photoelectric conversion. The scanning unit 401 (reading means) may be a contact image sensor (CIS) or a charge-coupled device (CCD) type image sensor.

[0022] The reading unit 103 can perform a fixed-position reading operation by moving the scanning unit 401 in the Y direction (sub-scanning direction) below the document glass 301 to read image information from a stationary document set on the document glass 301. In addition, the reading unit 103 can perform a scrolling reading operation by positioning the scanning unit 401 below the scrolling glass 300 to read image information from a document transported by the ADF 102 through the scrolling glass 300.

[0023] The reader frame 103A includes a lower frame 407 (first frame) and an upper frame 408 (second frame). The lower frame 407 includes a bottom surface portion 407b that is substantially rectangular in top view and a peripheral wall that extends upward from the outer periphery of the bottom surface portion 407b. The bottom surface portion 407b forms at least a part of the bottom surface of the entire image reading device 101. The upper frame 408 is a frame member that includes a top surface portion that is substantially rectangular in top view, a peripheral wall that extends downward from the outer periphery, and an opening formed in the top surface portion. The scanning glass 300 and the document glass 301 are attached to the upper frame 408. In this embodiment, the upper frame 408 includes a first opening to which the scanning glass 300 is attached and a second opening to which the document glass 301 is attached.

[0024] The upper frame 408 is mounted so as to cover the lower frame 407 from above. The scanning unit 401 is housed in the internal space formed between the upper frame 408, to which the scanning glass 300 and the document glass 301 are attached, and the lower frame 407.

[0025] In this embodiment, the lower frame 407 and upper frame 408 are made of resin material. In other words, the reader frame 103A of the reading unit 103 is not a metal frame, but is made of resin frame members (407, 408). The upper frame 408 and lower frame 407, together with the scanning glass 300 and the document glass 301, form a thin, rectangular prism-shaped housing (structural frame). However, the above description does not prevent the use of metal in part of the reader frame 103A. For example, a metal material may be used as part of the upper frame 408 or the lower frame 407 by a two-color molding method.

[0026] As shown in Figure 4, the reading unit 103 has a plurality of components for driving the scanning unit 401, which are arranged in the internal space of the reader frame 103A. In this embodiment, the plurality of components arranged in the internal space of the reader frame 103A include a shaft 400, a bearing member 403, a motor 404, a timing belt 405, and a home position sensor 406.

[0027] The shaft 400 extends in the Y direction (sub-scanning direction), which is intersecting the sheet width direction (X direction), and is fixed to the lower frame 407. The shaft 400 is an example of a guide member that guides the movement of the scanning unit 401 (reading means). The bearing member 403 supports the scanning unit 401 and has a hole through which the shaft 400 is inserted, and is movable in the Y direction along the shaft 400. The bearing member 403 is fixed to the timing belt 405. The timing belt 405 is stretched over pulleys 405a and 405b, which are spaced apart in the Y direction, and is rotationally driven by the motor 404. The rotational drive of the timing belt 405 by the driving force of the motor 404 allows the scanning unit 401 to reciprocate in the Y direction along the shaft 400. In this embodiment, the scanning unit 401 moves along the shaft 400, which is located in the center of the sheet width direction.

[0028] The home position sensor 406 is a sensor capable of detecting when the scanning unit 401 is in a predetermined position in the Y direction. The home position sensor 406 may be an optical sensor that is shielded by a light-shielding part provided on the scanning unit 401 when the scanning unit 401 is in the position when it performs a continuous reading (the position facing the continuous reading glass 300). In this case, the home position sensor 406 includes a light-emitting part that emits light, a light-receiving part into which light from the light-emitting part is incident, and a sensor circuit that drives the light-emitting part and converts the state change of the light-receiving part into an electrical signal for output.

[0029] (ADF) As shown in Figures 1 and 2, the ADF 102 includes an ADF frame 102A, a document tray 200, an output tray 201, a plurality of transport units 202, and contact parts (501, 502) that can come into contact with the scan glass 300. Note that Figure 1 is a schematic diagram, and for example, the plurality of transport units 202 in the ADF 102 are not necessarily arranged in the positions shown.

[0030] The ADF frame 102A is supported by the reader frame 103A of the reading unit 103 via a hinge portion 503 (Figures 5 and 6) provided at the rear end of the ADF 102. The hinge portion 503 rotatably connects the reading unit 103 and the ADF 102. Although Figures 5 and 6 show one hinge portion 503, the ADF 102 may be supported by two or more hinge portions 503 arranged side by side in the Y direction.

[0031] The ADF102 can be opened and closed relative to the reading unit 103 by rotating it around an axis extending in the Y direction due to the operation of the hinge portion 503. In this embodiment, the position where the contact portions (501, 502) of the ADF102 contact the reading glass 300 of the reading unit 103 is called the closed position of the ADF102. The position where the ADF102 is rotated so that the contact portions (501, 502) are separated from the reading glass 300 is called the open position of the ADF102.

[0032] The document tray 200 and the output tray 201 are supported by the ADF frame 102A, or are integrally formed with the frame members constituting the ADF frame 102A. The frame members constituting the ADF frame 102A may be made of resin.

[0033] Multiple transport units 202 are arranged along a U-shaped curved transport path that passes from the document tray 200 through the inside of the ADF 102A to the output tray 201. The multiple transport units 202 may include a pickup roller that feeds documents from the document tray 200, a pair of separation rollers that separate and transport the fed documents one by one, and a pair of lead rollers positioned adjacent to each other on the upstream side of the scanning glass 300. The multiple transport units 202 may also include a pair of output rollers that discharge the documents that have passed through the scanning glass 300 into the output tray 201.

[0034] As shown in Figure 5, a guide piece 508 and a platen guide 509 are positioned on the underside of the ADF 102, facing the scanning glass 300. The platen guide 509 is positioned facing the scanning unit 401 during the scanning operation and is a white board that serves as the background when the scanning unit 401 reads image information from the document. When the ADF 102 is closed, a document transport path is formed between the scanning glass 300 and the platen guide 509. The guide piece 508 is a piece of plastic film that guides the document being transported inside the ADF 102 towards the transport path between the scanning glass 300 and the platen guide 509. The guide piece 508 is in contact with the scanning glass 300 when the ADF 102 is closed.

[0035] (Abutting part) As shown in Figure 5, the ADF 102 (transport unit) has a first contact portion 501 and a second contact portion 502 (first abutment portion and second abutment portion). The first contact portion 501 and the second contact portion 502 protrude downward from the lower surface of the ADF frame 102A. As shown in Figures 6 and 7(b), the first contact portion 501 is positioned on one side (rear side, first side) of the center W0 of the reading glass 300 in the sheet width direction (X direction). The second contact portion 502 is positioned on the other side (front side, second side) of the center W0 of the reading glass 300 in the sheet width direction.

[0036] In this embodiment, the first contact portion 501 is positioned on one side (rear side) in the X direction with respect to the reading range 401a of the scanning unit 401, and the second contact portion 502 is positioned on the other side (front side) in the X direction with respect to the reading range 401a. The reading range 401a is the range in the X direction in which the scanning unit 401 (reading means) can acquire image information by optically scanning the document. The first contact portion 501 is positioned on one side (rear side) in the X direction with respect to the document passage area, and the second contact portion 502 is positioned on the other side (front side) in the X direction with respect to the document passage area. The document passage area is the region in the X direction through which the largest document with the longest dimensions in the X direction (sheet width direction) among the documents that the ADF 102 can transport passes.

[0037] When the ADF 102 is closed, the first contact portion 501 and the second contact portion 502 come into contact with the upper surface 300a (the surface that contacts the document) of the scanning glass 300, which serves as the first surface (Figure 6). As a result, the ADF 102 is positioned with respect to the upper surface 300a of the scanning glass 300. Also, when the ADF 102 is closed, a transport path for the document is formed between the upper surface 300a of the scanning glass 300 and the ADF 102. Because the ADF 102 is positioned, the transport path is formed with high precision, and the position of the document passing through the scanning glass 300 is stabilized, thereby improving the image reading accuracy of the reading unit 103.

[0038] More specifically, the above-described skimming operation is performed with the ADF 102 closed. When the ADF 102 is closed, the first contact portion 501 and the second contact portion 502, which are provided on both outer sides in the sheet width direction of the platen guide 509 (Figure 5) exposed on the lower surface of the ADF 102, come into contact with the skimming glass 300. As a result, a transport path is accurately formed between the upper surface 300a of the skimming glass 300 and the platen guide 509.

[0039] (Skimming through glass) In this embodiment, the scan glass 300 is made of glass with a thickness of, for example, 2.5 mm to 3.5 mm. The type of glass is not particularly limited, but float glass (transparent plate glass, ordinary glass) or chemically strengthened glass can be used. Furthermore, the scan glass 300 (translucent member) is not limited to one whose main component is silicate, but can be any material that has light transmittance suitable for reading image information from a document.

[0040] In this case, when the ADF 102 is closed, the scanning glass 300 may bend due to the pressing force received from the first contact portion 501 and the second contact portion 502. When the scanning glass 300 bends, the position of the document passing in the thickness direction (the depth of field direction in the optical system of the scanning unit 401 that guides reflected light from the document to the photodetector) changes depending on the position in the sheet width direction, which may reduce the accuracy of image reading. In particular, while reducing the thickness of the scanning glass 300 can reduce weight and cost, it also reduces rigidity, making it more prone to bending.

[0041] Therefore, in this embodiment, we propose a support structure that can reduce the deflection of the slide-read glass 300.

[0042] (Support structure for skimming glass) The support structure for the reading glass 300 in the reading unit 103 will now be described. As shown in Figure 6, the reading unit 103 has support parts (601 to 605) that support the lower surface 300b of the reading glass 300 as the second surface. The reading unit 103 in this embodiment has five support parts (first support part 601, second support part 602, third support part 603, fourth support part 604, fifth support part 605).

[0043] Each support portion (601-605) is provided on the leader frame 103A (frame). In this embodiment, each support portion (601-605) is supported on the bottom surface portion 407b (see also Figure 4) of the lower frame 407 (first frame) of the leader frame 103A. Each support portion (601-605) is either integrally formed with the bottom surface portion 407b as part of the lower frame 407, or is a separate component from the lower frame 407 and fixed to the lower frame 407.

[0044] In this embodiment, at least one of the first support portion 601, the second support portion 602, the third support portion 603, and the fourth support portion 604 is integrally formed with the lower frame 407 (first frame). This reduces the number of parts in the image reading device 101. Also, in this embodiment, at least one of the first support portion 601, the second support portion 602, the third support portion 603, and the fourth support portion 604 is a separate component from the lower frame 407 (first frame). More specifically, in the configuration example of this embodiment shown in Figure 6, the first support portion 601, the second support portion 602, and the fourth support portion 604 are integrally formed as part of the lower frame 407, while the third support portion 603 and the fifth support portion 605 are separate components fixed to the lower frame 407.

[0045] It is possible to choose whether each support part (601-605) is integrally formed as part of the lower frame 407 or as a separate component from the lower frame 407. For example, all support parts (601-605) may be integrally formed as part of the lower frame 407.

[0046] The reading glass 300 is a thin, elongated plate-like member that extends in the sheet width direction (X direction). As shown in Figures 6 and 7(b), the five support parts (601 to 605) are arranged at different positions in the sheet width direction. The position of each support part (601 to 605) refers to the position of the contact area of ​​the support part with respect to the lower surface 300b of the reading glass 300.

[0047] The first support portion 601 is positioned at one end (rear) of the reading glass 300 in the sheet width direction. The second support portion 602 is positioned at the other end (front) of the reading glass 300 in the sheet width direction.

[0048] The first contact portion 501 and the second contact portion 502 of the ADF 102, which are in contact with the reading glass 300, are located between the first support portion 601 and the second support portion 602 in the sheet width direction. In other words, the first support portion 601 is positioned behind (on the first side of) the first contact portion 501 in the sheet width direction. The second support portion 602 is positioned in front of (on the second side of opposite to the first side of) the second contact portion 502 in the sheet width direction. The first support portion 601 and the second support portion 602 support (hold) the lower surface 300b of the reading glass 300 outside the first contact portion 501 and the second contact portion 502 in the longitudinal direction (sheet width direction) of the reading glass 300.

[0049] The third support portion 603 is positioned within the range from the first contact portion 501 to the second contact portion 502 in the sheet width direction. The fourth support portion 604 is positioned within the range from the first contact portion 501 to the second contact portion 502 in the sheet width direction, and is located further forward (towards the second) than the third support portion 603.

[0050] The "range from the first contact portion 501 to the second contact portion 502 in the sheet width direction" includes the contact areas of the first contact portion 501 and the second contact portion 502 with respect to the reading glass 300. Therefore, the third support portion 603 may be positioned such that at least a portion of the area in which the third support portion 603 and the reading glass 300 come into contact in the sheet width direction overlaps with the area in which the first contact portion 501 and the reading glass 300 come into contact. Similarly, the fourth support portion 604 may be positioned such that at least a portion of the area in which the fourth support portion 604 and the reading glass 300 come into contact in the sheet width direction overlaps with the area in which the second contact portion 502 and the reading glass 300 come into contact.

[0051] According to this embodiment, the first support portion 601, the second support portion 602, the third support portion 603, and the fourth support portion 605 support the lower surface 300b (second surface) of the read-through glass 300, thereby reducing the deflection of the read-through glass 300 due to the load from the ADF 102.

[0052] In other words, when the ADF 102 is closed, a downward load is applied to the reading glass 300 from the first contact portion 501 and the second contact portion 502 due to the weight of the ADF 102, etc. If the reading glass 300 is supported only by the first support portion 601 and the second support portion 602 which are outside the first contact portion 501 and the second contact portion 502, the reading glass 300 may bend so that the central part of the reading glass 300 is recessed below the ends. Also, if the reading glass 300 is supported only by the support portion inside the first contact portion 501 and the second contact portion 502, the reading glass 300 may bend so that the central part of the reading glass 300 protrudes above the ends. In contrast, according to this embodiment, the bending that causes the reading glass 300 to be recessed downward can be reduced mainly by the third support portion 603 and the fourth support portion 604. Furthermore, according to this embodiment, the first support portion 601 and the second support portion 602 can reduce the deflection that causes the central part of the reading glass 300 to protrude upward.

[0053] Preferably, the heights of the upper surfaces (contact surfaces with the reading glass 300) of each support portion (601-605) in the thickness direction (Z direction) of the reading glass 300 are equal to each other.

[0054] In this embodiment, the third support portion 603 is positioned forward (to the second side) of the first contact portion 501. Also, in this embodiment, the fourth support portion 604 is positioned rearward (to the first side) of the second contact portion 502. In other words, the third support portion 603 and the fourth support portion 604 support (hold) the lower surface 300b of the reading glass 300 inside the first contact portion 501 and the second contact portion 502 in the longitudinal direction (sheet width direction) of the reading glass 300.

[0055] The third support portion 603 is preferably positioned near the first contact portion 501 in the sheet width direction, and the fourth support portion 604 is preferably positioned near the second contact portion 502 in the sheet width direction. In this embodiment, the third support portion 603 is positioned in the region Wa on the side of the first contact portion 501 (rear side, first side) when the range from the first contact portion 501 to the second contact portion 502 in the sheet width direction is divided into three equal parts. Also in this embodiment, the fourth support portion 604 is positioned in the region Wc on the side of the second contact portion 502 (front side, second side) when the range from the first contact portion 501 to the second contact portion 502 in the sheet width direction is divided into three equal parts.

[0056] Furthermore, if the positional relationship does not hinder the movement of the scanning unit 401, for example, at least a portion of the third support portion 603 may overlap with the first contact portion 501 when viewed in the thickness direction of the scanning glass 300 (the Z direction in this embodiment). Also, at least a portion of the fourth support portion 604 may overlap with the second contact portion 502 when viewed in the thickness direction of the scanning glass 300.

[0057] The scanning unit 401 includes, in addition to the sensor substrate on which the light-receiving element (photoelectric conversion element) is placed, a light source, a light guide, a lens array constituting a 1:1 optical system or a mirror constituting a reduction optical system, a housing that accommodates these, and the like. The third support portion 603 and the fourth support portion 604 of this embodiment are arranged so as not to interfere with the scanning unit 401 when it is in the position for skimming.

[0058] The fifth support portion 605 is positioned between the third support portion 603 and the fourth support portion 604 in the sheet width direction. In other words, the fifth support portion 605 is positioned in front of the third support portion 603 and behind the fourth support portion 604 in the sheet width direction. The fifth support portion 605 supports (holds) the lower surface 300b of the reading glass 300 further inward than the third support portion 603 and the fourth support portion 604 in the longitudinal direction (sheet width direction) of the reading glass 300.

[0059] By arranging the fifth support portion 605, the downward bending of the reading glass 300 can be further reduced. In other words, even if the fifth support portion 605 is omitted, the downward bending of the reading glass 300 can be reduced mainly by the third support portion 603 and the fourth support portion 604. However, by arranging the fifth support portion 605, even if the third support portion 603 and / or the fourth support portion 604 are lower than the first support portion 601 and the second support portion 602 due to, for example, dimensional tolerances of the parts, the downward bending of the reading glass 300 can be reduced.

[0060] The fifth support portion 605 is preferably positioned near the center of the first contact portion 501 and the second contact portion 502 in the sheet width direction. For example, the fifth support portion 605 is preferably positioned in the central region Wb when the area from the first contact portion 501 to the second contact portion 502 in the sheet width direction is divided into three equal parts. This further reduces the deflection of the reading glass 300. In this embodiment, the centers of the first contact portion 501 and the second contact portion 502 substantially coincide with the center W0 of the reading glass 300 and the center of the reading range 401a in the sheet width direction.

[0061] The aforementioned shaft 400 is positioned near the center of the first contact portion 501 and the second contact portion 502 in the sheet width direction (near the center of the scanning glass 300 and near the center of the reading range 401a). By positioning the shaft 400 in the center in the sheet width direction, it is possible to reduce the tilting of the scanning unit 401 when moving the scanning unit 401 along the shaft 400.

[0062] The shaft 400 extends over approximately the entire length of the leader frame 103A in the sub-scanning direction (Y direction), and the fifth support portion 605 is positioned differently from the shaft 400 in the sheet width direction. In this embodiment, the fifth support portion 605 is positioned in front of the shaft 400 (between the shaft 400 and the fourth support portion 604 in the sheet width direction). In this embodiment, the motor 404 is positioned behind the shaft 400 (between the shaft 400 and the third support portion 603 in the sheet width direction).

[0063] As shown in Figure 7(b), the first support portion 601 and the second support portion 602 are positioned to overlap with the reading range 401a in the sub-scanning direction (Y direction) of the scanning unit 401. In other words, the positions of the first support portion 601 and the second support portion 602 in the direction of movement of the document being transported along the slide-reading glass 300 (downward in the figure) at least partially overlap with the position of the reading range 401a in the direction of movement of the document.

[0064] The first support portion 601 and the second support portion 602 are positioned outside the reading range 401a in the sheet width direction (X direction). Therefore, by positioning the first support portion 601 and the second support portion 602 so as to overlap with the reading range 401a in the sub-scanning direction (Y direction), the flow-reading glass 300 can be held more stably at the reading position during flow-reading. Furthermore, by positioning the first contact portion 501 and the second contact portion 502 so as to overlap with the reading range 401a in the sub-scanning direction of the scanning unit 401, the transport path at the reading position can be formed with greater precision, contributing to improved image reading accuracy.

[0065] On the other hand, the third support portion 603, the fourth support portion 604, and the fifth support portion 605 are positioned inside the reading range 401a in the sheet width direction (X direction). Furthermore, the third support portion 603, the fourth support portion 604, and the fifth support portion 605 are positioned outside the reading range 401a in the sub-scanning direction (Y direction) of the scanning unit 401. Therefore, the third support portion 603, the fourth support portion 604, and the fifth support portion 605 can be positioned without hindering the movement of the scanning unit 401. In this embodiment, the third support portion 603, the fourth support portion 604, and the fifth support portion 605 are positioned on the opposite side of the document glass 301 from the reading range 401a of the scanning unit 401 in the sub-scanning direction of the scanning unit 401 during continuous scanning.

[0066] (Reinforcement member) As shown in Figure 7(a), a reinforcing member 701 for reinforcing the reading glass 300 is attached to the upper frame 408. The reinforcing member 701 is made of metal and extends in the sheet width direction (longitudinal direction of the reading glass 300) over a range that encompasses the reading range 401a of the scanning unit 401. The reinforcing member 701 in this embodiment is a sheet metal member that extends over substantially the entire length of the reading glass 300 in the sheet width direction.

[0067] One of the long sides of the scan glass 300 (one end of the scan glass 300 in the sub-scanning direction) is sandwiched between the upper frame 408 and the reinforcing member 701 in the thickness direction (Z direction) of the scan glass 300. In other words, at least a portion of one end of the scan glass 300 (transparent member) extending in the sheet width direction is sandwiched between the upper frame 408 (second frame) and the reinforcing member 701 in the thickness direction of the scan glass 300.

[0068] The reinforcing member 701 prevents the reading glass 300 from warping so that its central portion protrudes above both ends in the sheet width direction. For example, suppose that due to dimensional tolerances of the parts, the first support portion 601 and the second support portion 602 are lower than the third support portion 603 and the fourth support portion 604. In this case, when the ADF 102 is closed, a downward load due to the weight of the ADF 102 is applied to the reading glass 300 from the first contact portion 501 and the second contact portion 502 located outside the third support portion 603 and the fourth support portion 604. However, by reinforcing the reading glass 300 with the reinforcing member 701, it is possible to prevent warping such that its central portion protrudes above both ends. Furthermore, by using a sheet metal reinforcing member 701, the amount of warping can be reduced compared to when the warping of the reinforcing member 701 is restricted only by the resin upper frame 408.

[0069] (Details of the third and fifth support sections) The third support portion 603 and the fifth support portion 605, which are separate components from the lower frame 407, will be explained further.

[0070] As shown in Figure 8, the third support portion 603 functions as a holder for the home position sensor 406. In other words, the third support portion 603 is integrally formed with the sensor holder portion 603a to which the home position sensor 406 is attached. The home position sensor 406 is attached to the sensor holder portion 603a, and the integrally formed part including the sensor holder portion 603a and the third support portion 603 is attached to the lower frame 407, thereby fixing the home position sensor 406 to the reader frame 103A. This configuration reduces the number of parts in the image reading device 101 compared to when the third support portion 603 and the sensor holder portion 603a are separate parts, thereby reducing parts costs and assembly man-hours.

[0071] Furthermore, the fifth support portion 605 functions as a fixing portion that secures the shaft 400 to the lower frame 407. In other words, the fifth support portion 605 is integrally formed with the shaft fixing portion 605a that secures the shaft 400. By attaching the integrally formed part, including the shaft fixing portion 605a and the fifth support portion 605, to the lower frame 407, the shaft 400 is positioned by the shaft fixing portion 605a. This configuration reduces the number of parts in the image reading device 101 compared to a case where the fifth support portion 605 and the shaft fixing portion 605a are separate parts, thereby reducing parts costs and assembly man-hours.

[0072] In this embodiment, an example was described in which the third support portion 603 and the sensor holding portion 603a for the home position sensor 406 are integrally formed, but the sensor holding portion 603a may hold other sensors. Also, in this embodiment, an example was described in which the fifth support portion 605 and the shaft fixing portion 605a are integrally formed, but the fixing portion integrally formed with the fifth support portion 605 may fix (position) parts other than the shaft 400. Furthermore, support portions other than the third support portion 603 and the fifth support portion 605 (601, 602, 604) may be integrally formed with parts that perform the function of holding (fixing, positioning) other members, such as the sensor holding portion 603a or the shaft fixing portion 605a.

[0073] 《Second Embodiment》 A second embodiment of this disclosure will be described using Figures 9(a)(b), 10, and 11(a)-(c). In this embodiment, the details of the hinge portion 504, which has the function of stabilizing the posture of the ADF 102, and the relationship between the biasing force of the hinge portion 504 and the support configuration of the reading glass 300 will be explained.

[0074] Figure 9(a) is a perspective view showing the hinge portion 504. Figure 9(b) is a side view of the hinge portion 504 as seen in the Y direction. Figure 10 is an exploded view of the hinge portion 504. Figures 11(a) to (c) are schematic diagrams of the image reading device 101 as seen in the Y direction, and are diagrams for explaining the function of the hinge portion 504. For the purpose of explaining the structure of the hinge portion 504, for convenience of explanation, it will be described using the front-to-back direction (X direction), left-to-right direction (Y direction), and up-to-down direction (Z direction) of the image reading device 101 as if it were fixed to the image forming apparatus 100.

[0075] As shown in Figures 9(a)(b) and 10, the hinge portion 504 includes a fixed member 31, a first rotating member 32, a second rotating member 33, and a third rotating member 34. The hinge portion 504 also includes a hinge pivot shaft 35, a lift shaft 33A, a book pivot shaft 36, an equalizing shaft 37, an equalizing spring 71, and a torque applying portion 50.

[0076] The fixed member 31 is fixed to the leader frame 103A. The first rotating member 32 is supported by the fixed member 31 via the hinge pivot shaft 35 and is rotatable relative to the fixed member 31. The book pivot shaft 36 is held by the first rotating member 32. The second rotating member 33 is supported by the first rotating member 32 via the book pivot shaft 36 and is rotatable relative to the first rotating member 32. The lift shaft 33A and the equalizer shaft 37 are held by the second rotating member 33. The third rotating member 34 is supported by the second rotating member 33 via the equalizer shaft 37 and is rotatable relative to the second rotating member 33. The third rotating member 34 is also fixed to the ADF frame 102A and moves together with the ADF 102.

[0077] The equalizing spring 71 is an example of a biasing member configured to apply a downward force to the ADF 102 (conveyor unit) when the ADF 102 is closed. The fixing member 31 is an example of a first member fixed to the frame of the reading unit. The hinge pivot shaft 35 is an example of a first shaft supported by the first member. The module consisting of the lift shaft 33A, the first pivot member 32, the second pivot member 33, and the book pivot shaft 36 is an example of a pivot unit that rotates relative to the first member around the first shaft. The equalizing shaft 37 is an example of a second shaft supported by the pivot unit. The third pivot member 34 is an example of a second member fixed to the frame of the conveyor unit and rotatable relative to the pivot unit around the second shaft. Note that the pivot unit may be formed from a single member (or multiple members fastened together so as not to move relative to each other).

[0078] The details of each component of the hinge portion 504 will now be described. As shown in Figure 10, the fixing member 31 has a bottom plate (not shown) fixed to the leader frame 103A, a pair of side plates 31d extending upward from the bottom plate, and a back plate 31e extending upward from the bottom plate. That is, the fixing member 31 is formed in a box shape with openings at the top and front by the bottom plate, side plates 31d, and back plate 31e. In addition, each of the pair of side plates 31d has a through hole 31a. The hinge pivot shaft 35 is inserted into and supported in the through hole 31a so that its axial direction is in the left-right direction.

[0079] The torque-applying unit 50 includes a spring member housed inside the fixed member 31 and biases the lift shaft 33A by taking a reaction force from the fixed member 31. As a result, the rotation unit 30, including the lift shaft 33A, the first rotating member 32, the second rotating member 33, and the book rotation shaft 36, is biased in the direction of opening the ADF 102 around the hinge rotation shaft 35 (counterclockwise in Figure 9(b)). The torque-applying unit 50 applies torque to the rotation unit 30 in the opening direction of the ADF 102 using the biasing force (elastic force) of the spring member, according to the opening / closing angle An1 of the first rotating member 32. The opening / closing angle An1 (Figure 9(b)) is the rotation angle of the first rotating member 32 relative to the fixed member 31 with the hinge rotation shaft 35 as the fulcrum, with the ADF 102 in the closed position as the reference point.

[0080] As shown in Figure 10, the first rotating member 32 has a top plate 32c and a pair of side plates extending downward from the top plate 32c. The first rotating member 32 is formed in a U-shape so as to cover the fixed member 31 from above. Each of the pair of side plates has a through hole 32a at its rear end and a through hole 32b at its front end. The hinge pivot shaft 35, which is also inserted into the through hole 31a of the fixed member 31, is inserted through the rear through hole 32a. The book pivot shaft 36 is inserted and supported in the front through hole 32b so that its axial direction is in the left-right direction. Therefore, the book pivot shaft 36 is positioned parallel to the hinge pivot shaft 35 at a different position. The first rotating member 32 is configured to be rotatable relative to the fixed member 31 with the center CT1 of the hinge pivot shaft 35 as the pivot point.

[0081] As shown in Figure 10, the second rotating member 33 has a top plate 33c and a pair of side plates 33d extending downward from the top plate 33c. In other words, the second rotating member 33 has plate-shaped side plates 33d that are substantially perpendicular to the book rotation axis 36, the lift axis 33A, and the equalization axis 37. The second rotating member 33 also has a plate-shaped top plate 33c that is substantially perpendicular to the side plates 33d. That is, the second rotating member 33 is formed in a U-shape so as to cover the first rotating member 32 from above.

[0082] Furthermore, through holes 33a are formed near the front ends of the pair of side plates 33d, and another through hole 33b is formed further forward of the first through hole 33b. The book pivot shaft 36, which is also inserted into the through hole 32a of the first pivot member 32, is inserted into the through hole 33a. The equalizer shaft 37 is inserted into the through hole 33b so that its axial direction is left-right. Therefore, the lift shaft 33A and the equalizer shaft 37 are arranged parallel to the book pivot shaft 36 at different positions. 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 as the pivot point.

[0083] The second rotating member 33, configured in this way, can rotate around the book rotation axis 36 in a direction opposite to the rotation direction of the first rotating member 32 around the hinge rotation axis 35 (clockwise direction in Figure 9(b)). As the second rotating member 33 rotates with the third rotating member 34 relative to the first rotating member 32, the ADF 102 can be positioned in a nearly horizontal position regardless of the opening / closing angle An1 of the first rotating member 32, as long as the opening / closing angle An1 of the first rotating member 32 is within a predetermined range. For example, when scanning an image of a thick document such as a book placed on the document glass 301, the ADF 102 being in a nearly horizontal position allows the document to be firmly pressed against the document glass 301.

[0084] As shown in Figure 10, the third rotating member 34 has a top plate 34c and a pair of side plates 34d extending downward from the top plate 34c. These side plates 34d are arranged to face each other. In other words, the third rotating member 34 has a pair of plate-shaped side plates 34d that are substantially perpendicular to the equalization axis 37, and a plate-shaped top plate 34c that is substantially 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. The top plate 34c of the third rotating member 34 is positioned above the top plate 33c of the second rotating member 33.

[0085] Furthermore, through holes 34a are formed at the front ends of the pair of side plates 34d. An equalizing shaft 37 is inserted through the through holes 34a. In other words, the equalizing shaft 37 is supported at the end of the rotating unit 30 opposite to the hinge pivot shaft 35. The third rotating member 34 is configured to rotate relative to the second rotating member 33 with the center CT3 of the equalizing shaft 37 as the pivot point. The equalizing shaft 37 may be fixed to the side plate 34d of the third rotating member 34 by crimping, or it may be rotatably supported by the side plate 34d of the third rotating member 34 and the side plate 33d of the second rotating member 33.

[0086] Furthermore, each side plate 34d has a support plate portion 34g integrally formed by bending the sheet metal, with, for example, five screw holes 34b. The support plate portion 34g is fastened to the ADF frame 102A by screwing screws through the screw holes 34b into the ADF frame 102A. As a result, the third rotating member 34 and the ADF frame 102A are integrated, and the third rotating member 34 moves integrally with the ADF 102.

[0087] Furthermore, as shown in Figure 10, the equalizing spring 71 is mounted by being inserted through a first screw 72 fixed to the second rotating member 34. The first screw 72 is screwed into a screw hole 33e formed at the front end of the top plate 33c of the second rotating member 33. In addition, a first groove 34e is formed in the top plate 34c of the third rotating member 34 at a position corresponding to the screw hole 33e. One end of the equalizing spring 71 abuts against the head 72b of the first screw 72, and the other end abuts against the top plate 34c of the third rotating member 34 around the first groove 34e. The equalizing spring 71 may be a compression coil spring.

[0088] The equalizing spring 71 biases the third pivoting member 34 downward on the opposite side of the equalizing axis 37 in the front-rear direction, i.e., on the rear side. The action of this equalizing spring 71 will be described later.

[0089] Furthermore, a restricting portion 80 is provided alongside the first screw 72 in the left-right direction. The restricting portion 80 includes a second screw 82 fixed to the second pivoting member 33, a cylindrical collar 81 through which the second screw 82 is inserted, and a second groove 34f of the third pivoting member 34 that engages with the collar 81. The restricting portion 80 has the function of restricting the position of the third pivoting member 34 in the left-right direction and the function of limiting the range of rotation of the third pivoting member 34 relative to the second pivoting member 33.

[0090] [Equalization operation] Next, the equalization operation of the hinge portion 504 will be explained using Figures 11(a) to (c). Figure 11(a) is a schematic side view showing the ADF 102 in a closed state without bending. Figure 11(b) is a schematic side view showing the ADF in a bent state with the front abutment portion abutting against the image reading unit. Figure 11(c) is a schematic side view showing the ADF in a bent state with both the front abutment portion and the rear abutment portion abutting against the image reading unit.

[0091] The above-described skimming operation is performed with the ADF 102 closed. With the ADF 102 closed, both the first contact portion 501 and the second contact portion 502 contact the skimming glass 300, thereby maintaining the correct orientation of the ADF 102 relative to the reading unit 103.

[0092] Figure 11(a) shows the case where the rigidity of the ADF 102 is high and the relative dimensions of the first contact portion 501 and the second contact portion 502 and the upper surface 40S of the reading unit 103, including the upper surface 300a of the reading glass 300, match. In this case, when the ADF 102 is closed, both the first contact portion 501 and the second contact portion 502 naturally come into contact with the upper surface 300a of the reading glass 300.

[0093] However, deformation of the reader frame 103A or ADF frame 102A may occur due to manufacturing tolerances or changes over time after initial use. In this case, as shown in Figure 11(b), even if the ADF 102 is closed to a position where one of the first contact portion 501 and the second contact portion 502 contacts the upper surface 300a of the reading glass 300, the other of the first contact portion 501 and the second contact portion 502 may not contact the upper surface 300a of the reading glass 300.

[0094] As a specific example, in recent years, resin frames are sometimes used as frame members constituting the leader frame 103A and / or ADF frame 102A in order to reduce weight. Since resin frames generally have lower rigidity than metal frames, for example, if an upward force Ft is continuously applied to the ADF 102A by the torque applied by the torque application unit 50, the ADF frame 102A may deform over time. As shown in Figure 11(b), the ADF 102 sags downward due to its own weight W in front of its center of gravity (hereinafter referred to as "front sag"), so the front second contact part 502 contacts the read-through glass 300 first. Therefore, if the ADF 102A deforms over time due to the force Ft caused by the torque applied by the torque application unit 50, even if the ADF 102 is closed, the rear first contact part 501 will not be able to contact the read-through glass 300.

[0095] In contrast, in the hinge portion 504 of this embodiment, the equalizing spring 71 biases the third rotating member 34 in a counterclockwise direction around the equalizing axis 37. The third rotating member 34 is fixed to the ADF frame 102A. The biasing direction of the equalizing spring 71 (counterclockwise direction in the figure) is the direction that pushes down the rear end (lifts up the front end) of the ADF 102. Therefore, as shown in Figure 11(c), even if the front of the ADF 102 sags due to changes over time, the rear first contact portion 501 can be brought into contact with the read-through glass 300.

[0096] In this embodiment, the equalizing spring 71 supplies a biasing force to maintain (equalize) the parallelism of the ADF 102 with respect to the flow-reading glass 300 when the ADF 102 is closed, regardless of dimensional tolerances of the parts or changes over time. That is, the hinge portion 504 located at the rear (first) end of the reading unit 103 applies a moment to the ADF 102, directed downwards at the rear end of the ADF 102, by the biasing force of the equalizing spring 71 (biasing member) when the ADF 102 is closed. The equalizing spring 71 in this embodiment biases the third rotating member 34 (second member) such that the above moment is generated around the equalizing axis 37 (second axis).

[0097] As described above, the hinge portion 504 of this embodiment has the function of ensuring that both the first contact portion 501 and the second contact portion 502 come into more reliable contact with the reading glass 300 when the ADF 102 is closed, due to the biasing force of the equalizing spring 71.

[0098] On the other hand, the biasing force of the equalizing spring 71 acts downward on the ADF 102 when the ADF 102 is closed. Therefore, compared to the case where the equalizing spring 71 is omitted, the total downward load applied to the reading glass 300 from the first contact portion 501 and the second contact portion 502 is larger in this embodiment.

[0099] Here, the read-through glass 300 in this embodiment is supported by the same support structure as the read-through glass 300 described in the first embodiment. Therefore, even if the total downward load applied to the read-through glass 300 from the first contact portion 501 and the second contact portion 502 increases by using the hinge portion 504 equipped with the equalizing spring 71, the deflection of the read-through glass 300 can be reduced. In other words, the support structure of the read-through glass 300 according to the first and second embodiments is particularly useful in configurations where the biasing force of the biasing member (equalizing spring 71) provided in the hinge portion 504 acts downward on the ADF 102.

[0100] (modified version) In the second embodiment, an equalizing spring 71 for equalizing the ADF 102 was described as an example of a biasing member. However, the biasing member may be, for example, a spring built into the hinge so as to change the biasing direction according to the opening angle of the ADF 102. When the opening angle of the ADF 102 is greater than or equal to a predetermined angle, this spring biases the ADF 102 in the opening direction to reduce the operating load due to the weight of the ADF 102. When the opening angle of the ADF 102 is less than the predetermined angle, it biases the ADF 102 in the closing direction to position the ADF 102 in the closed position.

[0101] Other embodiments In the embodiments described above, an image reading device 101 mounted on top of the printer body 104 as part of the image forming apparatus was described. However, this technology is not limited to this and can also be applied to image reading devices that can be used independently of the image forming apparatus. [Explanation of Symbols]

[0102] 102...Transport Unit (ADF) / 103...Reading Unit / 103A...Frame (Reader Frame) / 300...Transparent Member (Swipe-Reading Glass) / 401...Reading Means (Scanning Unit) / 407...First Frame (Lower Frame) / 408...Second Frame (Upper Frame) / 501...First Contact Part / 502...Second Contact Part / 601...First Support Part / 602...Second Support Part / 603...Third Support Part / 604...Fourth Support Part / 605...Fifth Support Part

Claims

1. A reading unit having a frame, a light-transmitting member supported by the frame, and a reading means for reading image information from a sheet through the light-transmitting member, A transport unit configured to be openable and closable relative to the reading unit, transports a sheet from which image information is read by the reading means, Equipped with, The transport unit has a first contact portion positioned on the first side relative to the center of the light-transmitting member in the sheet width direction perpendicular to the sheet transport direction, and a second contact portion positioned on the second side opposite to the first side relative to the center of the light-transmitting member in the sheet width direction, and is configured such that when the transport unit is closed, the first contact portion and the second contact portion contact the first surface of the light-transmitting member. The aforementioned frame includes: A first support portion is positioned on the first side of the first contact portion in the sheet width direction and supports the second surface of the light-transmitting member opposite to the first surface, A second support portion is positioned on the second side of the second contact portion in the sheet width direction and supports the second surface of the light-transmitting member, A third support portion is positioned within the range from the first contact portion to the second contact portion in the sheet width direction and supports the second surface of the light-transmitting member, A fourth support portion is located within the range from the first contact portion to the second contact portion in the sheet width direction and is positioned on the second side of the third support portion, and supports the second surface of the light-transmitting member, It is provided. An image reading device characterized by the following:

2. The frame includes a first frame which includes a bottom portion that forms the bottom surface of the image reading device. The first support portion, the second support portion, the third support portion, and the fourth support portion are supported by the bottom surface portion. The image reading device according to feature 1.

3. The frame includes a second frame which has an opening in which the light-transmitting member is placed and is attached to cover the first frame from above. The first frame and the second frame are formed of a resin material. The image reading device according to feature 2.

4. The second frame further comprises a metal reinforcing member that is attached to the light-transmitting member and reinforces the light-transmitting member. The image reading device according to feature 3.

5. The reinforcing member extends in the sheet width direction over a range that includes at least the reading range over which the reading means reads the image information, At least a portion of the end of the light-transmitting member extending in the sheet width direction is sandwiched between the second frame and the reinforcing member in the thickness direction of the light-transmitting member. The image reading device according to feature 4.

6. At least one of the first support portion, the second support portion, the third support portion, and the fourth support portion is formed integrally with the first frame. The image reading device according to feature 2.

7. At least one of the first support portion, the second support portion, the third support portion, and the fourth support portion is a separate member from the first frame and is fixed to the first frame. The image reading device according to feature 2.

8. The first support portion and the second support portion are positioned outside the reading range in the sheet width direction where the reading means reads image information, and overlapping with the reading range in the sheet transport direction. The third support portion and the fourth support portion are positioned inside the reading range in the sheet width direction and outside the reading range in the sheet transport direction. The image reading device according to feature 1.

9. The third support portion is positioned in the first region when the area from the first contact portion to the second contact portion is divided into three equal parts in the sheet width direction. The fourth support portion is positioned in the second region when the range from the first contact portion to the second contact portion is divided into three equal parts in the sheet width direction. The image reading device according to feature 8.

10. The third support portion is positioned on the second side of the first contact portion in the sheet width direction, The fourth support portion is positioned on the first side of the second contact portion in the sheet width direction. The image reading device according to feature 1.

11. The frame is provided with a fifth support portion, which is positioned between the third support portion and the fourth support portion in the sheet width direction and supports the second surface of the light-transmitting member. The image reading device according to feature 1.

12. The fifth support portion is positioned in the central region when the area from the first contact portion to the second contact portion is divided into three equal parts in the sheet width direction. The image reading device according to feature 11.

13. A guide member extending in a direction intersecting the sheet width direction and guiding the movement of the reading means, A fixing portion for fixing the guide member to the frame, Furthermore, The fifth support portion is formed integrally with the fixing portion. The image reading device according to feature 11.

14. A sensor for detecting the position of the reading means in a direction intersecting the sheet width direction, A holding part for holding the sensor, Furthermore, Any one of the first support portion, the second support portion, the third support portion, and the fourth support portion is integrally formed with the holding portion. The image reading device according to feature 1.

15. The device further includes a hinge portion that rotatably connects the reading unit and the transport unit, The hinge portion includes a biasing member configured to apply a downward force to the transport unit when the transport unit is closed. The image reading device according to feature 1.

16. The hinge portion is positioned at the first end of the reading unit in the sheet width direction, and is configured to apply a downward moment to the first end of the conveying unit by the biasing force of the biasing member when the conveying unit is closed. The image reading device according to feature 15.

17. The aforementioned hinge portion is, A first member fixed to the frame of the reading unit, The first shaft is supported by the first member, A rotating unit that rotates relative to the first member around the first axis, A second shaft supported by the aforementioned rotating unit, A second member fixed to the frame of the transport unit and rotatable relative to the rotation unit around the second axis, Includes, The biasing member biases the second member such that the moment is generated around the second axis when the transport unit is closed. The image reading device according to feature 16.

18. An image reading device according to any one of claims 1 to 17, An image forming means capable of performing an image forming operation to form an image on a recording material based on the image information read by the image reading device, An image forming apparatus characterized by comprising:

Images