Image reading device and image forming device

Abstract

To improve the accuracy of reading performed by a reading unit.SOLUTION: An image reading device comprises a second reading unit 20 that is rotatably supported by support parts at both ends in a sheet width direction, can be displaced through rotation to a closed position where it forms a conveyance path through which a sheet is conveyed and an open position where it opens the conveyance path, and reads an image of the sheet conveyed through the conveyance path at the closed position. The second reading unit 20 has a projection 27. A rear side plate 40 has a rib part 44 that is brought into contact with the projection 27 when the second reading unit 20 is at the closed position and thereby regulates the movement of the second reading unit 20 in a first direction W1.SELECTED DRAWING: Figure 11

Description

[Technical Field]

[0001] The present invention relates to an image reading device that reads an image from a document, and an image forming apparatus to which this image reading device is applied. [Background technology]

[0002] Conventionally, image reading devices mounted on image forming devices such as copiers and printers have been widely used, equipped with an automatic document feeder (hereinafter also referred to as "sheet") that separates and feeds documents (hereinafter also referred to as "sheets") placed on a document tray as a sheet conveying device. One such image reading device has been developed that includes a second reading unit on the automatic document feeder side in addition to a first reading unit on the reader side having a glass on which the documents are placed (see Patent Document 1). This configuration makes it possible to realize a one-pass double-sided scanning function that can read image information on both sides of a double-sided document without flipping it over, thereby increasing productivity for scanning double-sided documents.

[0003] In this image reading device, it is desirable that the transport path formed by the second reading unit be openable in order to clear jams in the transport path near the second reading unit or to clean the glass to eliminate scanning streaks caused by dirt on the glass of the second reading unit. Therefore, in this image reading device, the second reading unit and a rotary guide unit, which is located downstream of the second reading unit in the sheet transport direction and has a guide surface downstream of the second reading unit in the sheet transport direction, are rotatable about their respective rotary axes to open and close like a double door. This makes it possible to open the transport path formed by the second reading unit in this image reading device, facilitating maintenance such as clearing jams and cleaning the glass. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2023-004032 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the image reading device described in Patent Document 1, the second reading unit is rotatable, and it is desirable for this rotation to be smooth in consideration of maintenance workability. Therefore, the second reading unit needs to be installed with play (backlash) in the main scanning direction (sheet width direction) relative to the front and rear side plates, which are the front and rear frames of the automatic document feeder. Because the second reading unit is installed with backlash relative to the front and rear frames in this way, there is a risk that the positioning accuracy of the second reading unit in the main scanning direction relative to the front and rear frames will decrease, resulting in a decrease in reading accuracy.

[0006] SUMMARY OF THE INVENTION An object of the present invention is to provide an image reading device and an image forming device that can improve the reading accuracy of a reading unit. [Means for solving the problem]

[0007] One aspect of the present invention is an image reading device comprising: a support portion; a conveying portion supported by the support portion and conveying a sheet; a case having both ends in a sheet width direction perpendicular to the sheet conveying direction each rotatably supported by the support portion and including a transparent member; and a reading sensor housed in the case and reading an image of the sheet through the transparent member, the reading portion being displaceable by rotation between a closed position that forms a conveying path through which the sheet is conveyed and an open position that opens the conveying path, and reading an image of the sheet conveyed through the conveying path in the closed position; the reading portion having a first abutment portion, and the support portion having a first abutted portion that abuts against the first abutment portion when the reading portion is positioned in the closed position, thereby restricting movement of the reading portion in a first direction in the sheet width direction from the first abutment portion toward the center of the transparent member.

[0008] One aspect of the present invention is an image forming apparatus including the image reading device described above and an image forming unit that forms an image on a sheet. [Effects of the Invention]

[0009] According to the present invention, the reading accuracy of the reading unit can be improved. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic view showing an image forming apparatus according to a first embodiment. [Figure 2] FIG. 1 is a perspective view showing an image reading apparatus according to a first embodiment. [Figure 3] FIG. 1 is a cross-sectional view showing an image reading apparatus according to a first embodiment. [Figure 4] FIG. 3 is a cross-sectional view of a second reading unit according to the first embodiment. [Figure 5] FIG. 4 is a front view showing a state in which the second reading unit and the inner cover according to the first embodiment are in a closed position. [Figure 6] FIG. 10 is a front view showing a state in which the inner cover according to the first embodiment is pushing up the second reading unit. [Figure 7] FIG. 4 is a front view showing a state in which the second reading unit and the inner cover according to the first embodiment are in an open position. [Figure 8] (a) is an oblique view showing the relationship between the second reading unit and the front and rear plates in the first embodiment, (b) is an oblique view showing the relationship between the second reading unit and the front plate, and (c) is an oblique view showing the relationship between the second reading unit and the rear plate. [Figure 9] FIG. 4 is a perspective view showing an end portion on the second direction side of the second reading unit according to the first embodiment. [Figure 10] 1A and 1B are diagrams showing the rear side panel according to the first embodiment in a cut state, in which (a) is a perspective view seen from an angle close to the front, (b) is a perspective view seen from an angle close to the right side, and (c) is an enlarged perspective view of a portion of (b). [Figure 11] 1A and 1B are diagrams showing the rear panel cut away when the second reading unit of the first embodiment is rotated from the open position to the closed position, where (a) is an oblique view seen from an angle close to the front, and (b) is an oblique view seen from an angle close to the right side. [Figure 12]FIG. 4 is a perspective view showing a state in which the rear panel is cut away when the second reading unit according to the first embodiment is located at a closed position. [Figure 13] This figure shows the state in which the rear panel is cut away when the second reading unit of the second embodiment is rotated from the closed position, where (a) is an oblique view seen from an angle close to the right side, and (b) is an enlarged oblique view of a portion of (a). DETAILED DESCRIPTION OF THE INVENTION

[0011] First Embodiment A first embodiment of the present invention will be described in detail below with reference to FIGS. 1 to 12. First, the schematic configuration of an image forming apparatus 1 according to this embodiment will be described with reference to FIG. 1. FIG. 1 is a cross-sectional view showing the image forming apparatus 1 according to this embodiment. Note that this embodiment is applied to a full-color copier equipped with multiple photosensitive drums. However, the present invention is not limited to this, and can also be applied to monochrome or mono-color copiers or printers equipped with a single photosensitive drum, or inkjet printers.

[0012] [Image forming device] An image forming apparatus 1 will be described with reference to FIG. 1. The image forming apparatus 1 is configured to include an image reading device 10 above an image forming apparatus main body 2. The image forming apparatus 1 transports a sheet P conveyed from a sheet cassette 105 to an image forming unit 106, which forms a toner image on the sheet P. The image forming apparatus 1 transports the sheet P on which the toner image has been formed in the image forming unit 106 to a fixing device 107, which applies heat and pressure to fix the unfixed toner on the sheet P to the sheet P. That is, the image forming unit 106 forms an image read by the image reading device 10 on the sheet. Examples of the sheet P include paper such as thin paper and cardboard, plastic film such as overhead projector sheet (OHP), surface-treated paper such as coated paper, specially shaped sheets such as envelopes, and cloth.

[0013] The image forming unit 106 has stations 111, 112, 113, and 114. The image forming apparatus 1 includes an intermediate transfer belt 115 and a secondary outer transfer roller 116. The stations 111, 112, 113, and 114 form yellow, magenta, cyan, and black toner images, respectively, on the intermediate transfer belt 115. The stations 111, 112, 113, and 114 have the same configuration except for the toner colors. The toner images formed by the stations 111, 112, 113, and 114 are transferred onto the intermediate transfer belt 115. The secondary outer transfer roller 116 transfers the toner image on the intermediate transfer belt 115 onto a sheet P transported from a sheet cassette 105. The fixing device 107 applies heat and pressure to the sheet P to fix the toner image transferred to the sheet P. The sheet P with the fixed toner image is discharged to a discharge tray 119.

[0014] [Image reader] Fig. 2 is a perspective view showing the image reading device 10. In Fig. 2, the front side of the image reading device 10 (the side where the operation unit of the image forming device 1 is arranged) is represented as the front direction F, the back side is represented as the rear direction B, the right side is represented as the right direction R, the left side is represented as the left direction L, the top side is represented as the upward direction U, and the bottom side is represented as the downward direction D.

[0015] As shown in FIG. 2, the image reading device 10 has a reader 103 for reading an image of a document set by a user, and an ADF 102 (Auto Document Feeder) above the image forming apparatus main body 2. FIG. 3 is a cross-sectional view showing the image reading device 10. As shown in FIG. 3, the ADF 102 transports a plurality of documents set in a document tray 200 into the inside thereof, whereby the document images can be read by a first reading unit 306 and a second reading unit 20 mounted therein. Specifically, the documents placed on the document tray 200 are transported along a transport path 11 by a feed roller 300, a transport roller pair 301, a transport roller pair 302, and a transport roller pair 303. The ADF 102 also has a support portion as a support body for supporting each portion. The support portion includes, for example, structural members such as a frame and a front side panel 30 and a rear side panel 40 (see FIG. 9(a)).

[0016] Image information on the first side of the document is read by a first reading unit 306 mounted inside the reader 103 through a first flow reading glass 312. The document is then transported by a pair of transport rollers 304, and image information on the second side, opposite the first side, is read by a second reading unit 20 mounted inside the ADF 102 through a second flow reading glass 21. The document after reading is discharged to a discharge tray 201 by a pair of discharge rollers 305. Furthermore, by opening and closing the ADF 102, the reader 103 can read the image of the document placed on the document glass by moving and scanning the first reading unit 306. In this embodiment, the feed roller 300, the pair of transport rollers 301, the pair of transport rollers 302, the pair of transport rollers 303, the pair of transport rollers 304, the pair of discharge rollers 305, and the motors and transmission mechanisms that drive these components are collectively referred to as a transport section 310. That is, the conveying section 310 is supported by the support section 104 and conveys the sheet.

[0017] In this embodiment, the ADF 102 includes a main unit 102a, an outer cover 12, a separation guide member 500, and a second reading unit 20, which is an example of a reading section. The main unit 102a is a housing including a transport guide member 507, a reading guide member 403, and frames such as a front side panel 30 and a rear side panel 40, which will be described later, and defines a transport path 11 therein. As shown in FIG. 2, the outer cover 12 forms the upper surface of the ADF 102. The outer cover 12 is rotatable relative to the main unit 102a and can be opened and closed between a closed position where the outer cover 12, together with the separation guide member 500, defines an upper transport path 11a, which is an example of a first region of the transport path 11, and an open position where the upper transport path 11a is open. In this embodiment, when the outer cover 12 is in the closed position, the upper transport path 11a is defined between the transport guide member 507 and the separation guide member 500. The lower surface of the outer cover 12 faces the upper surface of the document being transported, and the upper surface of the separation guide member 500 faces the lower surface of the document being transported. The reading guide member 403 is disposed on the opposite side of the second reading unit 20 from the separation guide member 500, and forms a lower transport path 11b between the second reading unit 20 and the reading guide member 403, which is continuous with the upper transport path 11a downstream of the transport path 11. The second reading unit 20 is disposed in a position between the upper transport path 11a and the lower transport path 11b in the transport path 11, which is curved in a substantially U-shape in the vertical direction.

[0018] [Second reading unit] FIG. 4 is a cross-sectional view of the second reading unit 20. As shown in FIG. 4, the second reading unit 20 includes a case 22, a CIS 23, which is a contact image sensor, and a second flow reading glass 21, which is an example of a transparent member. The second reading unit 20 moves by rotation and linear movement relative to a transport guide member 507 (see FIGS. 5 to 7) provided in the main unit 102a. In this embodiment, the second reading unit 20 moves by rotation and linear movement relative to the transport guide member 507, but this is not limited thereto. The second reading unit 20 may move only by rotation, only by linear movement, or in other relative movements. The CIS 23, which is an example of a reading sensor, is housed in the case 22 and reads an image of a sheet through the second flow reading glass 21. The CIS 23 is connected to a control unit via an FFC (not shown) and reads an image of a sheet transported along the lower transport path 11b of the transport path 11.

[0019] An opening 402 is provided on the transport path side of the case 22 for reading the transported image information, and a second flow reading glass 21 is attached so as to cover the opening 402. Meanwhile, a reading guide member 403 is arranged on the outside of the second flow reading glass 21, i.e., on the transport path side. A white sheet 405 and its protective glass 404 are provided on the reading guide member 403 so as to face the CIS 23. The white sheet 405 is provided to perform shading correction for the CIS 23 before reading the image information of the original, and the protective glass 404 is provided to prevent the surface of the white sheet 405 from being scratched by the transported original.

[0020] In this embodiment, the second reading unit 20 is an example of a reading section, and both end portions in the sheet width direction perpendicular to the sheet conveying direction are rotatably supported by support portions 104. Here, the second reading unit 20 is rotatably supported at both end portions by the front side plate 30 and the rear side plate 40 (see FIG. 8(a)). The second reading unit 20 can be displaced by rotation between a closed position that forms the lower conveying path 11b and an open position that opens the lower conveying path 11b, and reads an image of a sheet conveyed through the lower conveying path 11b in the closed position. In this embodiment, the second running reading glass 21 is rectangular in shape.

[0021] [Rotational movement] Next, the manner in which the second reading unit 20 rotates inside the ADF 102 of this embodiment will be described with reference to Figures 5 to 7. Figures 5 to 7 are front views showing the rotation configuration of the second reading unit 20 of this embodiment. As shown in Figure 5, inside the ADF 102, a conveying guide is configured by a separation guide member 500, a conveying guide member 507, a reading guide member 403, etc. Note that in this embodiment, a rough configuration is described, focusing on members necessary for explaining the configuration of the present invention.

[0022] The separation guide member 500 forms a transport guide on one side of the feeding and separating section. The separation guide member 500 is provided to be rotatable around a rotation shaft 502 relative to the main unit 102a. The separation guide member 500 is configured to be rotatable by a user for the purpose of clearing jams and cleaning the second running glass 21 provided in the second reading unit 20, the protective glass 404 of the white sheet 405, etc. Therefore, the separation guide member 500 can be opened and closed between a closed position (FIG. 5) in which it covers the second reading unit 20, and an open position (FIG. 7) in which it opens the second reading unit 20.

[0023] The second reading unit 20 has a first rotating shaft 24 (see FIG. 8(b)) provided on the front side (F) of the case 22 and a second rotating shaft 25 (see FIG. 9) provided on the rear side (B) of the case 22. The second rotating shaft 25 is an example of a rotating shaft, extends from the case 22 in the second direction (W2), and is supported by the rear side plate 40. The center line C1 of the first rotating shaft 24 and the second rotating shaft 25 is coaxial and extends in the front-to-rear direction. As a result, the second reading unit 20 is supported by the first rotating shaft 24 and the second rotating shaft 25 relative to the main unit 102a so as to be rotatable around the front-to-rear direction as a rotation center. The second reading unit 20 is rotatable between a reading position (see FIG. 5) in which the second running glass 21 faces the reading guide member 403 and an exposed position (see FIG. 7) in which the lower conveying path 11b is opened. Here, the reading position is the position when the second reading unit 20 reads an image of a document, and the exposed position is the position where the second flow reading glass 21 is exposed to the outside of the device when viewed from above. As shown in Fig. 3, the outer cover 12 covers the top of the separation guide member 500 when in the closed position. Therefore, by opening the outer cover 12 to the open position, the separation guide member 500 can be rotated.

[0024] The transport guide member 507 guides the document downstream of the separation guide member 500 and forms a transport guide on one side of the bent transport guide. The reading guide member 403 forms a transport guide on the opposite side to the second reading unit 20.

[0025] 5, a state will be described in which the second reading unit 20 and the separation guide member 500 are in the closed position. At this time, a pressing portion 505 provided on the separation guide member 500 presses a pressed portion 506 provided on the second reading unit 20 downward from above. As a result, the second flow reading glass 21 of the second reading unit 20 abuts against the opposing reading guide member 403 with a predetermined gap therebetween, thereby forming a conveyance path. Furthermore, a cam member 501 serving as an interlocking member is provided on a rotation shaft 502 of the separation guide member 500. A first contact portion 503 and a second contact portion 504 are provided on the separation guide member 500 and the cam member 501, respectively.

[0026] 6 is a front view showing a state in which the separation guide member 500 rotates in the direction D1 and pushes up the second reading unit 20 in the direction D2. When the separation guide member 500 rotates beyond a certain angle, the cam member 501 can also rotate in synchronization with the separation guide member 500 (see FIGS. 6 and 7). The second reading unit 20 is provided with a rotation shaft 314. When the separation guide member 500 rotates beyond a certain angle, the cam portion 509 of the cam member 501, which rotates in synchronization with the separation guide member 500, comes into contact with the second reading unit 20. As a result, the second reading unit 20 begins to rotate in the direction D2 around the rotation shaft 314 in conjunction with the rotation of the separation guide member 500.

[0027] 7 is a front view of the second reading unit 20 and the separation guide member 500 in the open position. As shown in FIG. 7, when the second reading unit 20 rotates to a certain angle, the pressed portion 506 provided on the second reading unit 20 abuts against the angle restricting portion 508 provided on the transport guide member 507, preventing further rotation. The second reading unit 20, whose rotation is restricted, then slides in the D3 direction by the cam member 501. The state shown in FIG. 7 is the state when the rotation of the second reading unit 20 is complete.

[0028] In this way, when a document is transported, the second flow reading glass 21 and the protective glass 404 of the white sheet 405 are inaccessible to the user, as shown in Fig. 5. In contrast, by rotating the second reading unit 20 and the separation guide member 500, the user can access both the second flow reading glass 21 and the protective glass 404 of the white sheet 405, as shown in Fig. 7. In particular, as shown in Fig. 7, the second reading unit 20 slides in the D3 direction in the latter half of the rotation operation, thereby ensuring a cleaning space for cleaning the protective glass 404 of the white sheet 405.

[0029] [Second reading unit installation configuration] Next, the mounting configuration of the front side plate 30 and the rear side plate 40 that constitute the frame of the second reading unit 20 and the ADF 102 will be described with reference to FIGS. 8(a) to 8(c). As shown in FIG. 8(a), the front side plate 30 and the rear side plate 40 are made of generally plate-shaped members that are arranged facing each other in the front-to-rear direction and are each fixed to a frame (not shown). The second reading unit 20 is provided between the front side plate 30 and the rear side plate 40. In the drawing, the width direction of the document being transported, i.e., the front-to-rear direction in which the front side plate 30 and the rear side plate 40 face each other, is designated as the main scanning direction W, the document transport direction perpendicular to the main scanning direction W is designated as the sub-scanning direction X, and the direction perpendicular to the main scanning direction W and the sub-scanning direction X is designated as the direction Z.

[0030] 8(b), a hole 31 is provided in the front side plate 30, penetrating in the front-rear direction, and a first rotation shaft 24 provided on the front side of the second reading unit 20 is fitted into the hole 31. The hole 31 is formed as an elongated hole with the direction Z as the longitudinal direction, to allow the second reading unit 20 to slide in the direction D3 shown in FIG.

[0031] As shown in FIG. 8(c), a rotation support part 41 is provided on the front side (F) of the rear side plate 40 to support the second rotation shaft part 25 (see FIG. 9) provided on the back side of the second reading unit 20 so that the second rotation shaft part 25 can rotate and move in the Z direction. The rotation support part 41 protrudes on the front side (F) of the rear side plate 40, and is made up of a pair of opposing ribs with the Z direction as the longitudinal direction, and is formed in a substantially U-shape with a closed lower portion in the Z direction (see FIG. 10(a)). The second rotation shaft part 25 is rotatably supported at the bottom of a groove part 42 at the lower end of the U-shape of the rotation support part 41, and is slidable upward in the groove part 42 in the Z direction (see FIG. 10(a)).

[0032] The second reading unit 20 is supported by the front side plate 30 and the rear side plate 40, and as shown in FIGS. 5 to 7, the second reading unit 20 is rotatable. Here, in the closed state shown in FIG. 5, the movement of the first rotating shaft 24 in the sub-scanning direction X is restricted by the hole 31, and the movement of the second rotating shaft 25 in the sub-scanning direction X is restricted by the rotation support portion 41. Therefore, the second reading unit 20 is positioned in the sub-scanning direction X relative to the front side plate 30 and the rear side plate 40. Also, in the closed state shown in FIG. 5, the second scanning glass 21 of the second reading unit 20 abuts against the reading guide member 403 with a predetermined gap therebetween. Therefore, the second reading unit 20 is positioned in the direction Z relative to the front side plate 30 and the rear side plate 40 via the reading guide member 403.

[0033] On the other hand, when attaching the second reading unit 20 in the main scanning direction W, play is provided between the front side plate 30 and the rear side plate 40 and the second reading unit 20 to facilitate the rotational movement of the second reading unit 20. This reduces the positioning accuracy of the second reading unit 20 relative to the front side plate 30 and the rear side plate 40 in the main scanning direction W, which could result in a reduction in reading accuracy. Therefore, in this embodiment, a positioning section is provided to position the second reading unit 20 in the main scanning direction W.

[0034] [Main scanning direction W positioning configuration] Next, the positioning configuration of the second reading unit 20 relative to the front plate 30 and the rear plate 40 in the main scanning direction W will be described with reference to FIGS. 9 to 12(b). Here, in the main scanning direction W, the front direction F is referred to as the first direction W1, and the opposite rear direction B is referred to as the second direction W2. Here, the first direction W1 is, in other words, the direction from a protrusion 27 (described later) toward the center of the second flow reading glass 21 in the main scanning direction W. In further words, the first direction W1 is the direction toward the center of the second reading unit 20 in the main scanning direction W, or the direction toward the conveyance center of the conveyance unit 310, or the direction toward the center of the conveyance path. Furthermore, the first direction W1 may be the center of the main scanning direction W in terms of the design direction in which the conveyance unit 310 conveys the sheet. In this embodiment, the image reading device 10 has a first positioning part 51 that positions the second reading unit 20 in the first direction W1 and a second positioning part 52 that positions the second reading unit 20 in the second direction W2 (see FIG. 8(c)). Also, in this embodiment, the second reading unit 20 is positioned relative to the front side plate 30 and the rear side plate 40, and is positioned so that the reading center of the second reading unit 20 in the main scanning direction W coincides with the conveying center of the conveying path 11 in the width direction.

[0035] 9, the second reading unit 20 has, on the second direction W2 side, a second rotation shaft 25 of the second reading unit 20 and a flange portion 26 that supports the second rotation shaft 25 relative to the case 22. The flange portion 26 also has a ring portion 28 that surrounds the periphery of the second rotation shaft 25 and is made of a ring-shaped rib that is an example of a second abutment portion that protrudes in the second direction W2. The ring portion 28 is an end face on the second direction W2 side and has a second abutment surface 28a facing the second direction W2.

[0036] As shown in FIG. 10A, the rear side plate 40 has a rotation support portion 41, which is an example of a second abutment portion, protruding toward the first direction W1 (first direction side) of the rear side plate 40. The second rotation shaft portion 25 is rotatably fitted and supported at the bottom of a groove portion 42 of the rotation support portion 41 and is slidable in the groove portion 42 in the direction Z. An end surface 43 of the rotation support portion 41 on the first direction W1 side is an example of a second abutment surface and is a flat surface parallel to a plane perpendicular to the main scanning direction W. When the second rotation shaft portion 25 is supported in the groove portion 42, the annular portion 28 abuts in the second direction W2. In this way, the second positioning portion 52 is formed by the annular portion 28 and the rotation support portion 41. The annular portion 28 abuts against the end surface 43 of the rotation support portion 41, thereby restricting movement of the second reading unit 20 in the second direction W2 and positioning the second reading unit 20. That is, in this embodiment, the rotation support portion 41 for rotatably supporting the second rotation shaft portion 25 is used to position the second reading unit 20 in the second direction W2.

[0037] On the other hand, as shown in FIG. 9, the second reading unit 20 has a rib-shaped protrusion 27 that protrudes downward from the case 22 on the second direction W2 side. The protrusion 27 is an example of a first abutment portion and has a first abutment surface 27a facing the first direction W1. As shown in FIGS. 10(b) and 10(c), the rear side panel 40 has a rib 44 that extends upward from the bottom on the first direction W1 side. The thickness direction of the rib 44 is the left-right direction. The rib 44 is an example of a first abutment portion and has a first abutment surface 44a facing the second direction W2 at the end edge of the rib 44 on the second direction W2 side. When the second reading unit 20 is in the closed position, the first abutment surface 27a and the first abutment surface 44a abut against each other. In this way, the first positioning portion 51 is composed of the protrusion portion 27 and the rib portion 44, and the first abutment surface 27a of the protrusion portion 27 abuts against the first abutment surface 44a of the rib portion 44, thereby restricting movement of the second reading unit 20 in the first direction W1 and positioning it.

[0038] In this embodiment, when the second reading unit 20 is in the closed position, both the first positioning portion 51 and the second positioning portion 52 come into contact with each other. This allows the second reading unit 20 to be positioned while preventing it from moving in the main scanning direction W. When the second reading unit 20 is positioned, the flange portion 26 elastically deforms slightly in the first direction W1, and the biasing force of the flange portion 26 biases the first positioning portion 51 and the second positioning portion 52 in the main scanning direction W, thereby improving positioning accuracy.

[0039] 10(c), the rib portion 44 has a first guide surface 44b that is continuous upward from the first contact surface 44a. The first guide surface 44b is configured as an inclined surface whose upper side is inclined more toward the first direction W1 than its lower side. When the second reading unit 20 rotates from the open position to the closed position, if the first contact surface 27a is located further in the first direction W1 than the first contact surface 44a, the first guide surface 44b guides the first contact surface 27a in the second direction W2 and to a position where it contacts the first contact surface 44a.

[0040] In this embodiment, when the second reading unit 20 is in the open position, the first contact surface 27a does not contact the first guide surface 44b or the first contacted surface 44a. When the second reading unit 20 rotates from the open position to the closed position, just before reaching the closed position, as shown in FIGS. 11(a) and 11(b), the end surface 43 abuts against the annular portion 28, and the first contact surface 27a of the protrusion 27 abuts against the first guide surface 44b of the rib portion 44 and is guided. That is, when the second reading unit 20 rotates from the open position to the closed position, the first contact surface 27a does not contact the first guide surface 44b or the first contacted surface 44a until just before reaching the closed position. This allows for smooth rotation of the second reading unit 20. Furthermore, the provision of the first guide surface 44b allows the first contact surface 27a of the protrusion 27 to be smoothly guided into the first contacted surface 44a of the rib portion 44. Then, as shown in Figure 12, when the first abutment surface 27a of the protrusion portion 27 reaches the first abutted surface 44a of the rib portion 44, the second reading unit 20 is positioned in the closed position, and positioning in the main scanning direction W is completed.

[0041] As described above, the image reading device 10 of this embodiment includes the first positioning portion 51 that positions the second reading unit 20 in the first direction W1 and the second positioning portion 52 that positions the second reading unit 20 in the second direction W2. Therefore, when the second reading unit 20 is in the closed position, it is possible to accurately position the second reading unit 20 in the main scanning direction W, thereby improving reading accuracy. That is, with the configuration of this embodiment, when the second reading unit 20 is in a rotating state, there is a play in the main scanning direction W between the front side plate 30 and the rear side plate 40 and the second reading unit 20, enabling smooth rotation. Furthermore, when the second reading unit 20 is in the closed position, the first positioning portion 51 and the second positioning portion 52 abut against each other, thereby preventing play in the main scanning direction W between the front side plate 30 and the rear side plate 40 and the second reading unit 20. This enables highly accurate positioning of the second reading unit 20 in the main scanning direction W, thereby improving the reading accuracy of the scanned image even in an ADF 102 in which the second reading unit 20 rotates. In addition, in this embodiment, the protrusion 27 and the annular portion 28, which position the second reading unit 20 in the main scanning direction W, are both provided at the end portion that is deeper than the second flow reading glass 21. Furthermore, in this embodiment, a first positioning portion 51 that positions the second reading unit 20 in the first direction W1 and a second positioning portion 52 that positions the second reading unit 20 in the second direction W2 are separately arranged in the direction Z. This arrangement makes it possible to position the second reading unit 20 in a narrow space.

[0042] In the above-described embodiment, the case where both the first positioning portion 51 and the second positioning portion 52 are provided has been described, but this is not limiting. For example, the second positioning portion 52 may be omitted. In this case, for example, a configuration in which the second reading unit 20 is pressed in the first direction W1 by a biasing spring or the like, or a configuration in which a force acts in the first direction W1 due to the weight of the second reading unit 20 due to tilting or the like, can be adopted. In this way, the second reading unit 20 can be positioned in the main scanning direction W even without the second positioning portion 52.

[0043] In the above-described embodiment, the second reading unit 20 is supported by the front side plate 30 and the rear side plate 40 as the support portion 104, but this is not limiting. The second reading unit 20 may have any other shape as long as it is supported rotatably.

[0044] <Second embodiment> Next, a second embodiment of the present invention will be described in detail with reference to Fig. 13. This embodiment differs from the first embodiment in that the second positioning portion is disposed opposite the first positioning portion. However, other configurations are the same as those of the first embodiment, so the same reference numerals are used and detailed description will be omitted.

[0045] In this embodiment, the first positioning portion 51 shown in the first embodiment is provided in the same manner, but the second positioning portion 52 is not provided. A second positioning portion 53, which restricts movement of the second reading unit 20 in the second direction, is arranged opposite the first positioning portion 51 in the main scanning direction W. As shown in FIG. 13(a), the protrusion 27 of the second reading unit 20 is also an example of a second abutment portion and has a first abutment surface 27a facing the first direction W1 and a second abutment surface 27b facing the second direction W2. Also, as shown in FIG. 13(b), a rib portion 45, which is an example of a second abutted portion, is arranged on the rib portion 44 of the rear side plate 40 in the second direction W2. The rib portion 45 has a second abutment surface 45a, which is an example of a second abutment surface, on the end surface on the first direction W1 side, and a second guide surface 45b that extends continuously upward from the second abutment surface 45a. The second contact surface 45a and the second guide surface 45b are symmetrical to the first contact surface 44a and the first guide surface 44b, respectively, and therefore detailed description thereof will be omitted. In this manner, the second positioning portion 53 is composed of the second contact surface 27b and the second contact surface 45a, and the second contact surface 27b contacts the second contact surface 45a, thereby restricting movement of the second reading unit 20 in the second direction W2 and positioning the second reading unit 20.

[0046] In this embodiment, the distance between the first abutment surface 44a and the second abutment surface 45a in the main scanning direction W is set to be equal to or slightly narrower than the thickness of the protrusion 27. This allows both the first positioning portion 51 and the second positioning portion 53 to abut against each other when the second reading unit 20 is in the closed position. Therefore, the second reading unit 20 can be positioned while being prevented from moving in the main scanning direction W. [Explanation of symbols]

[0047] 1...image forming apparatus, 10...image reading device, 20...second reading unit (reading section), 21...second flow reading glass (transparent member), 22...case, 25...second pivot shaft section (rotating shaft section), 27...projection section (first abutment section, second abutment section), 27a...first abutment surface, 27b...second abutment surface, 28...annular section (second abutment section), 28a...second abutment surface, 41...rotation support section (second abutted section), 43...end surface (second abutted surface), 44...rib section (first abutted section), 44a...first abutment surface, 44b...first guide surface, 45a...second abutment surface, 45b...second guide surface, 104...support section, 106...image forming section, 310...conveying section

Claims

1. A support part; a conveying section supported by the support section and configured to convey a sheet; a case having both end portions in a sheet width direction perpendicular to a sheet conveying direction rotatably supported by the support portions and including a transparent member; a reading sensor housed in the case and reading an image of the sheet through the transparent member; the reading unit being displaceable by rotation between a closed position forming a conveying path along which the sheet is conveyed and an open position opening the conveying path, and reading an image of the sheet conveyed through the conveying path at the closed position; the reading unit has a first contact portion, the support portion has a first contact portion that contacts the first contact portion when the reading portion is located at the closed position, thereby restricting movement of the reading portion in a first direction from the first contact portion toward the center of the transparent member in the sheet width direction. An image reading device characterized by:

2. the first contacted portion does not contact the first contact portion when the reading unit is located at the open position; 2. The image reading device according to claim 1, wherein:

3. the reading unit has a second contact portion, the support portion has a second contact portion that contacts the second contact portion when the reading portion is located at the closed position, thereby restricting movement of the reading portion in a second direction, which is opposite to the first direction in the sheet width direction, and the first contact portion contacts the first contacted portion, and the second contact portion contacts the second contacted portion, thereby positioning the reading portion relative to the support portion in the sheet width direction.

2. The image reading device according to claim 1, wherein:

4. the first contact portion has a first contact surface facing the first direction in the seat width direction, the first contacted portion faces a second direction opposite to the first direction in the sheet width direction, and has a first contacted surface that contacts the first contact surface when the reading unit is located at the closed position; 2. The image reading device according to claim 1, wherein:

5. the first contacted portion has a first guide surface that is continuous with the first contacted surface and is inclined so as to guide the first contacted surface in the second direction and to a position where the first contacted surface contacts the first contacted surface when the reading unit rotates from the open position to the closed position and the first contacted surface is located further in the first direction than the first contacted surface; 5. The image reading device according to claim 4, wherein:

6. the second contact portion has a second contact surface facing the second direction in the seat width direction, the second contacted portion has a second contacted surface that faces the first direction in the sheet width direction and contacts the second contact surface when the reading unit is located at the closed position; 4. The image reading device according to claim 3, wherein:

7. the reading unit has a rotation shaft portion that extends from the case in the second direction and is supported by the support portion, the second contact portion is a ring portion that surrounds the periphery of the rotation shaft portion and protrudes from the case in the second direction, the second abutment surface is an end surface of the annular portion on the second direction side, the support portion has a rotation support portion that rotatably supports the rotation shaft portion, the second abutted portion is constituted by the rotation support portion, the second abutment surface is an end surface of the rotation support portion on the first direction side; 7. The image reading device according to claim 6, wherein:

8. The first contacted portion and the second contacted portion are disposed opposite to each other in the seat width direction.

7. The image reading device according to claim 6, wherein:

9. the second contacted portion has a second guide surface that is continuous with the second contacted surface and is inclined so as to guide the second contacted surface in the first direction and to a position where the second contacted surface contacts the second contacted surface when the reading unit rotates from the open position to the closed position and the second contacted surface is located in the second direction relative to the second contacted surface; 9. The image reading device according to claim 8, wherein:

10. An image reading device according to any one of claims 1 to 9; an image forming unit that forms an image on a sheet, An image forming apparatus characterized by:

Images