Image reader

Abstract

To prevent a reduction in image quality of a read image due to deformation of a housing of a reading unit.SOLUTION: An image reading device comprises: a reader 10; an ADF 20; hinge mechanisms 30; hinge attachment members 40; and coupling members 50. The hinge attachment member 40 has a first attachment part 41 attached to the reader 10 and a second attachment part 42 attached to the hinge mechanism 30, and attaches the hinge mechanism 30 to the reader 10. The coupling member 50 has a third attachment part 51 attached to the reader 10 at a position different from that of the first attachment part 41 and a fourth attachment part 52 attached to the hinge attachment member 40, and couples the reader 10 and the hinge attachment member 40 to each other. The hinge mechanism 30 is supported on the reader 10 by the hinge attachment member 40 and the coupling member 50.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to an image reading device that reads an image on a sheet. [Background technology]

[0002] Conventionally, image forming apparatuses such as printers and copiers are known that are provided with an image reading device at the top to read an image of an original. Such image reading devices include a reading unit (reading device main body) that reads an original, and a transport unit (automatic document feeder) that transports the original to the reading unit. The automatic document feeder (ADF) is provided on the reading unit by a hinge mechanism so as to be freely opened and closed. When a user wants to read an image of an original without using the ADF, the user lifts the ADF upward to open the document table of the reading unit, places the original on the document table, and reads the image. In addition, a document pressing plate is provided on the lower surface of the ADF, and when the ADF is closed downward, the document pressing plate presses the original against the document table.

[0003] As an attachment structure for the hinge mechanism that rotatably supports the ADF to the reading unit, for example, a structure is known in which a hinge attachment member is attached to the housing of the reading unit and the hinge mechanism is attached to the hinge attachment member by screwing (see Patent Document 1). Meanwhile, since some ADFs weigh more than 10 kg, a large load is applied when the user opens and closes them. For this reason, in the above-mentioned image reading device, the hinge mechanism attached to the ADF is provided with a mechanism (called a free stop mechanism) that reduces the load applied to the user and maintains the position during opening and closing. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2017-055164 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the configuration described in the above-mentioned Patent Document 1, since the hinge mechanism is attached to the reading unit by the hinge attachment member, the housing of the reading unit may be easily deformed depending on the usage situation. For example, when the ADF is opened substantially vertically, a downward load acts on the hinge attachment member, but when the ADF is held in an inclined position by the free stop mechanism, a torque acts on the hinge attachment member in addition to the downward load. In particular, in recent years, it has become common to make the housing of the reading unit out of synthetic resin in order to reduce costs. In this case, the housing of the reading unit may be easily deformed by the torque acting through the hinge attachment member by the ADF in an inclined position. Since deformation of the housing of the reading unit may lead to a deterioration in the image quality of the read image, it has been desired to suppress deformation of the housing of the reading unit in the mounting structure of the hinge mechanism.

[0006] SUMMARY OF THE DISCLOSURE An object of the present invention is to provide an image reading device capable of suppressing degradation in image quality of a read image caused by deformation of a housing of a reading unit. [Means for solving the problem]

[0007] The image reading device of the present invention comprises a reading unit that reads image information from a document placed at a first position on a reading surface; a transport unit that transports the document toward a second position on the reading surface; a hinge mechanism that rotatably supports the transport unit relative to the reading unit and enables the transport unit to be opened and closed by rotating the transport unit between a closed position in which the transport unit blocks the reading surface and an open position in which the transport unit opens the reading surface; a first mounting portion attached to the reading unit and a second mounting portion attached to the hinge mechanism, a hinge mounting member that attaches the hinge mechanism to the reading unit, a third mounting portion attached to the reading unit at a position different from the first mounting portion, and a fourth mounting portion attached to the hinge mounting member, and a connecting member that connects the reading unit and the hinge mounting member, wherein the hinge mechanism is supported on the reading unit by the hinge mounting member and the connecting member. Effect of the Invention

[0009] According to the present invention, it is possible to suppress deterioration in image quality of a read image caused by deformation of the housing of the reading unit. [Brief description of the drawings]

[0010] [Figure 1] 1 is a perspective view showing a state in which an ADF is closed in an image reading device according to a first embodiment. [Diagram 2] 1 is a perspective view showing a state in which an ADF is held in an inclined position in an image reading device according to a first embodiment. FIG. [Diagram 3] 2 is a cross-sectional view showing a state in which the image reading device according to the first embodiment is cut along the line AA in FIG. 1. [Figure 4] 3 is a cross-sectional view showing a state in which the image reading device according to the first embodiment is cut along the line BB in FIG. 2. [Diagram 5] FIG. 2 is a perspective view of the reading unit according to the first embodiment, seen from below. [Figure 6] FIG. 11 is a front view showing an image forming apparatus according to a second embodiment. [Figure 7] 13 is a cross-sectional view of an image reading device according to a second embodiment, showing a state in which an ADF is held in an inclined position, as viewed from the left side of the image reading device. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] <First embodiment> Hereinafter, a first embodiment of the present invention will be described in detail with reference to FIGS. 1 to 5. First, a configuration of an image reading device 1 will be described with reference to FIGS. 1 and 2. FIGS. 1 and 2 respectively show a state in which an ADF 20 is closed and an open state with respect to a reader 10 in the image reading device 1. The image reading device 1 includes a reader 10 which is an example of a reading unit, an ADF 20 which is an example of a transport unit, and a hinge mechanism 30 which supports the ADF 20 rotatably with respect to the reader 10. In this embodiment, the open end side of the ADF 20 is the front side F, the opposite side is the rear side B, the left side when facing the front side F is the left side L, and the right side is the right side R. In addition, sheets used as documents in the image reading device 1 include paper such as thin paper and thick paper, plastic films such as overhead projector sheets (OHP), surface-treated paper such as coated paper, sheets of special shapes such as envelopes, and cloth.

[0012] As shown in FIG. 2, the reader 10 has a housing 11 made of synthetic resin, a reading sensor unit 12, a guide shaft 13, a drive belt 14, a drive motor 15, a document table glass 16, and a flow reading glass 17. Of these, the reading sensor unit 12, the guide shaft 13, the drive belt 14, and the drive motor 15 are housed inside the housing 11. The document table glass 16, which is an example of a first position of the reading surface, and the flow reading glass 17, which is an example of a second position of the reading surface, are provided exposed on the upper part of the housing 11. That is, the reader 10 reads image information from a document placed on the document table glass 16. The ADF 20 transports the document toward the flow reading glass 17. In this embodiment, the document table glass 16 and the flow reading glass 17 are provided separately, but this is not limited thereto, and a part of the document table glass 16 may be used as the flow reading glass.

[0013] The user can select from two methods of document reading depending on the type of document, the situation, etc. One of the document reading methods is document platen reading, in which the document is placed on the document platen glass 16 and scanned, and the other is skimming reading, in which the document is placed on the document tray 21 provided in the ADF 20 with the ADF 20 closed and scanned.

[0014] In the former case of the document platen reading, the user places a document on the document platen glass 16 and then starts image reading. When image reading starts, the drive motor 15 moves the reading sensor unit 12 in the sub-scanning direction (hereinafter referred to as the moving direction) D1 via the drive belt 14. The reading sensor unit 12 reads the image of the document placed on the document platen glass 16 while being moved in the moving direction D1 by the drive motor 15. The document placed on the document platen glass 16 is pressed against the document platen glass 16 by the document pressing plate 22 provided on the ADF 20. When the user finishes reading the image of the document, he opens the ADF 20 and replaces the document placed on the document platen glass 16. The reading sensor unit 12 is not limited to a reduction optical system, and may be a reading device of a contact optical system (contact image sensor). For example, the reading sensor unit 12 may have a line image sensor extending in the main scanning direction perpendicular to the moving direction D1.

[0015] In the latter case of skimming, a user starts image reading after placing an original on the original tray 21 of the closed ADF 20. When image reading starts, the drive motor 15 moves the reading sensor unit 12 via the drive belt 14 to a predetermined reading position below the skimming glass 17, and the original conveyed by the ADF 20 is read under the skimming glass 17.

[0016] [Hinge mechanism] Next, the hinge mechanism 30 will be described with reference to Figures 3 and 4. The ADF 20 is connected and supported by two hinge mechanisms 30 provided at the end of the rear side B in an openable and closable state relative to the reader 10. The hinge mechanism 30 rotatably supports the ADF 20 relative to the reader 10, and by rotating the ADF 20, it is possible to open and close the ADF 20 between a closed position (Figure 3) where the ADF 20 closes the platen glass 16 and an open position (Figure 4) where the ADF 20 opens the platen glass 16.

[0017] The hinge mechanism 30 has an opening / closing plate 31 fixed to the ADF 20 by screws, a base plate 32 fixed to a hinge mounting member 40 provided on the reader 10 by screws, and a hinge shaft 33 rotatably connecting the opening / closing plate 31 and the base plate 32. The hinge mechanism 30 also has a torque generating mechanism 34 as an example of a biasing unit, and can hold the position at an intermediate angle by generating a torque that acts as a reaction force to cancel the torque (moment) generated by the mass during opening and closing of the ADF 20. That is, when the ADF 20 is opened beyond a predetermined angle (upper limit angle), the torque generating mechanism 34 generates a torque that is balanced with the torque due to the weight of the ADF 20. As a result, the hinge mechanism 30 has a free stop mechanism that reduces the load on the user when opening and closing the ADF 20 and holds the position during opening and closing.

[0018] [Hinge mounting parts] The image reading device 1 includes a hinge mounting member 40 attached to the housing 11 of the reader 10 by screwing. The hinge mounting member 40 has a first mounting portion 41 attached to the reader 10 and a second mounting portion 42 attached to the hinge mechanism 30, and attaches the hinge mechanism 30 to the reader 10. That is, the ADF 20 is fixed to the hinge mounting member 40 by a bolt via the hinge mechanism 30, and is provided so as to be freely opened and closed. The first mounting portion 41 of the hinge mounting member 40 is screwed to the housing 11 of the reader 10 by a bolt 61. The second mounting portion 42 of the hinge mounting member 40 is attached to the base plate 32 of the hinge mechanism 30 by a bolt 62.

[0019] In this embodiment, the second mounting portion 42 is screwed to the base plate 32 via the cover member 18 of the reader 10. In this manner, the first mounting portion 41, the second mounting portion 42, the third mounting portion 51, and the fourth mounting portion 52 described later may be directly screwed, or may be indirectly screwed by sandwiching another member. Also, the first mounting portion 41, the second mounting portion 42, the third mounting portion 51, and the fourth mounting portion 52 each have a certain area and are attached to a mating member. Furthermore, the first mounting portion 41, the second mounting portion 42, the third mounting portion 51, and the fourth mounting portion 52 are screwed by bolts 61, 62, 63, and 64, respectively, but are not limited thereto, and existing fastening methods such as adhesion and riveting can be appropriately applied.

[0020] Here, as shown in FIG. 4, when the ADF 20 is opened around the hinge shaft 33 with respect to the reader 10, the weight F1 of the ADF 20 is concentrated on the housing 11 of the reader 10 via the hinge mechanism 30 and the hinge mounting member 40. Furthermore, since the torque generated by the torque generating mechanism 34 is always generated in the direction of opening the hinge mechanism 30, the hinge mounting member 40 that fixes the hinge mechanism 30 is subjected to a load that lifts it upward. In other words, the load received by the hinge mounting member 40 is not only the weight F1 of the ADF 20, but also the reaction force T2 due to the torque T1 generated by the hinge mechanism 30. As a result, the housing 11 is deformed by the force acting on it, which may lead to a deterioration in the quality of the scanned image. For this reason, it is desirable to make the housing 11 and the hinge mounting member 40 of the image reading device 1 have a strong structure. Therefore, in this embodiment, a connecting member 50 that connects the housing 11 and the hinge mounting member 40 is provided to improve the rigidity of the mounting portion between the housing 11 and the hinge mounting member 40.

[0021] [Connecting parts] As shown in FIG. 3 to FIG. 5, the image reading device 1 includes a connecting member 50 that connects the reader 10 and the hinge mounting member 40. The connecting member 50 includes a third mounting portion 51 that is attached to the reader 10 and a fourth mounting portion 52 that is attached to the hinge mounting member 40. In this embodiment, the connecting member 50 is a substantially L-shaped bracket having a horizontal portion and a vertical portion, and the third mounting portion 51 is provided on the horizontal portion and the fourth mounting portion 52 is provided on the vertical portion. The third mounting portion 51 is attached to the reader 10 and has a mounting surface 51a that is parallel to the document table glass 16. The fourth mounting portion 52 is attached to the hinge mounting member 40 and has a mounting surface 52a that is perpendicular to the document table glass 16. The third mounting portion 51 is screwed to the housing 11 of the reader 10 by a bolt 63. The fourth mounting portion 52 is attached to the hinge mounting member 40 by a bolt 64. In this embodiment, the connecting member 50 is made of a bracket, but is not limited to this and may be of another shape.

[0022] The third mounting portion 51 is provided at a position different from the first mounting portion 41 of the hinge mounting member 40. In this embodiment, the first mounting portion 41 is provided at the front and rear portions of the hinge mounting member 40, and the third mounting portion 51 is disposed further forward F than the first mounting portion 41. In other words, the distance from the hinge shaft 33 to the third mounting portion 51 is longer than the distance from the hinge shaft 33 to the first mounting portion 41.

[0023] In this way, the hinge mechanism 30 is supported on the reader 10 by the hinge mounting member 40 and the connecting member 50. As a result, compared to a case in which the hinge mechanism 30 is supported on the reader 10 only by the hinge mounting member 40, the reaction force T2 due to the torque T1 generated by the hinge mechanism 30 can be received in a distributed manner by the third mounting portion 51 at a position different from the first mounting portion 41. Therefore, by providing the connecting member 50 that connects the housing 11 and the hinge mounting member 40, the rigidity of the mounting portion between the housing 11 and the hinge mounting member 40 can be improved.

[0024] In this embodiment, the third attachment portion 51 is attached to the bottom surface 11a of the housing 11. This allows the third attachment portion 51 to bear the weight of the reader 10, and therefore can more firmly support the hinge attachment member 40. However, the third attachment portion 51 is not limited to being attached to the bottom surface 11a of the housing 11, and may be attached to the side surface or interior of the housing 11 or to other attachment locations.

[0025] In this embodiment, the third mounting portion 51 has a length L2 (see FIG. 3) that is 10% or more of the length L1 (see FIG. 1) of the reader 10 in the direction perpendicular to the hinge shaft 33, i.e., the front-rear direction, when viewed from the vertical direction of the document table glass 16. If the third mounting portion 51 has a length less than 10% of the length L1 of the reader 10 in the front-rear direction, it may be difficult to obtain sufficient rigidity against the reaction force T2. In addition, the third mounting portion 51 is preferably 50% or less of the length L1 of the reader 10 in the front-rear direction. If the third mounting portion 51 has a length that exceeds 50% of the length L1 of the reader 10 in the front-rear direction, the connecting member 50 becomes excessively large, which may cause problems in assembling or increase the parts cost more than necessary. In this embodiment, for example, the weight of the ADF is 7 kg, the length L1 of the ADF is 504 mm, and the length L2 of the third mounting portion 51 is 183.2 mm, and the third mounting portion 51 is about 36% of the length of the reader 10 in the front-rear direction. In this way, when the third mounting portion 51 is 20 to 40% of the length L1 of the reader 10 in the front-rear direction, sufficient rigidity against the reaction force T2 can be obtained and the connecting member 50 does not become excessively large, which is particularly preferable. The ratio of the third mounting portion 51 to the length L1 of the reader 10 in the front-rear direction varies depending on the weight of the ADF 20 and the rigidity of the housing 11, and the above-mentioned numerical values ​​are merely examples.

[0026] As described above, according to the image reading device 1 of this embodiment, the hinge mechanism 30 is supported on the reader 10 by the hinge mounting member 40 and the connecting member 50. As a result, compared to the case where the hinge mechanism 30 is supported on the reader 10 only by the hinge mounting member 40, the reaction force T2 caused by the torque T1 generated by the hinge mechanism 30 can be received in a distributed manner by the third mounting portion 51 at a position different from the first mounting portion 41. Therefore, the rigidity of the mounting portion between the housing 11 and the hinge mounting member 40 can be improved, deformation of the housing 11 of the reader 10 can be suppressed, and deterioration of the image quality of the read image can be suppressed.

[0027] In addition, it is possible to prevent the position and posture of the hinge mounting member 40 from being displaced by the load acting on the hinge mounting member 40 when the ADF 20 is opened or closed, i.e., the weight F1 of the ADF 20 and the torque T1 generated by the hinge mechanism 30. As a result, even when the reader 10 and the ADF 20 are combined, the ADF 20 can maintain the correct posture relative to the reader 10, making it possible to suppress deterioration of the read image.

[0028] Furthermore, according to the image reading device 1 of this embodiment, the distance from the hinge shaft 33 to the third mounting portion 51 is set to be longer than the distance from the hinge shaft 33 to the first mounting portion 41. Therefore, when the hinge shaft 33 is the center, the third mounting portion 51 can receive a larger torque than the first mounting portion 41. This allows the third mounting portion 51 to more effectively receive the torque T1 generated in the hinge mechanism 30 and the reaction force T2 thereto.

[0029] In the above embodiment, the distance from the hinge shaft 33 to the third mounting portion 51 is longer than the distance from the hinge shaft 33 to the first mounting portion 41, but this is not limited to the above. For example, if the third mounting portion 51 can receive a larger torque than the first mounting portion 41 due to the rigidity of the mounting points, the distance from the hinge shaft 33 does not necessarily matter.

[0030] In the above embodiment, the connecting member 50 is a separate member from the hinge mounting member 40, but the present invention is not limited to this, and the connecting member 50 may be one member with the hinge mounting member 40. In this case, the hinge mounting member has a first mounting portion attached to the reader 10, a second mounting portion attached to the hinge mechanism 30, and a third mounting portion attached to the reader 10 at a position different from the first mounting portion, and the hinge mechanism 30 is attached to the reader 10. As a result, the hinge mechanism 30 is supported on the reader 10 by the first mounting portion and the third mounting portion of the hinge mounting member. Therefore, the reaction force T2 can be distributed and received by the third mounting portion compared to the case where the hinge mechanism 30 is supported on the reader 10 only by the first mounting portion, and the rigidity of the mounting portion between the housing 11 and the hinge mounting member 40 can be improved.

[0031] <Second embodiment> Next, a second embodiment of the present invention will be described in detail with reference to Figures 6 and 7. This embodiment differs from the first embodiment in that the hinge mounting member 40 is attached to the frame of the image forming device 70. However, other configurations are the same as those of the first embodiment, so the same reference numerals are used and detailed description is omitted.

[0032] As shown in FIG. 6, an image forming apparatus 70, which is an example of an image reading apparatus, includes an apparatus main body 71 and an image reading device 1 that is attached to the upper part of the apparatus main body 71 and reads an image of a document. The apparatus main body 71 includes an image forming section 72 (not shown), a feeding section (not shown) for feeding sheets as recording materials to the image forming section 72, and a tray 74 for stacking sheets on which images are formed by the image forming section 72. The image forming section 72 is configured as a print engine using a conventionally known electrophotographic method, and includes a laser writing section, an electrophotographic process section, a fixing section, and the like (not shown). That is, the image forming section 72 forms an image based on image information read by the reader 10. The feeding section includes a feeding roller (not shown) for separating and feeding sheets placed in a sheet cassette 73, and supplies the sheets to the image forming section 72.

[0033] The device body 71 has a frame 75 (see FIG. 7) that supports the image forming unit 72. As shown in FIG. 7, the hinge mounting member 40 of the image reading device 1 has a fifth mounting portion 43 that is attached to the frame 75. The fifth mounting portion 43 is screwed to the frame 75 by a bolt 65. Therefore, the hinge mounting member 40 is supported not only by the housing 11 of the reader 10 but also by the frame 75.

[0034] As described above, according to the image reading device 1 of this embodiment, the hinge mounting member 40 is supported by the housing 11 and the frame 75. As a result, compared to a case in which the hinge mounting member 40 is supported only by the housing 11, the reaction force T2 due to the torque T1 generated by the hinge mechanism 30 can be received in a more distributed manner by the third mounting portion 51 at a position different from the first mounting portion 41. This improves the rigidity of the mounting portion between the housing 11 and the hinge mounting member 40, suppresses deformation of the hinge mounting member 40 and the housing 11, etc., even if a strong impact is applied by a user's operation, and suppresses deterioration in the image quality of the read image. [Explanation of symbols]

[0035] 1...image reading device, 10...reader (reading unit), 11a...bottom surface, 16...original glass table (first position of reading surface), 17...flow reading glass (second position of reading surface), 20...ADF (transport unit), 30...hinge mechanism, 33...hinge shaft, 34...torque generating mechanism (urging section), 40...hinge mounting member, 41...first mounting section, 42...second mounting section, 43...fifth mounting section, 50...connecting member, 51...third mounting section, 51a...mounting surface, 52...fourth mounting section, 52a...mounting surface, 70...image forming device (image reading device), 72...image forming section, 75...frame, L1...length of reader, L2...length of third mounting section

Claims

1. a reading unit that reads image information from a document placed at a first position on a reading surface; a transport unit configured to transport the document toward a second position on the reading surface; a hinge mechanism that rotatably supports the transport unit with respect to the reading unit and that rotates the transport unit to open and close the transport unit between a closed position where the transport unit blocks the reading surface and an open position where the transport unit opens the reading surface; a hinge attachment member including a first attachment portion attached to the reading unit and a second attachment portion attached to the hinge mechanism, the hinge attachment member attaching the hinge mechanism to the reading unit; a third attachment portion attached to the reading unit at a position different from the first attachment portion, and a fourth attachment portion attached to the hinge attachment member, and a connecting member connecting the reading unit and the hinge attachment member; the hinge mechanism is supported on the reading unit by the hinge attachment member and the connecting member; 1. An image reading apparatus comprising:

2. a distance from a hinge shaft of the hinge mechanism to the third mounting portion is longer than a distance from the hinge shaft to the first mounting portion; 2. The image reading apparatus according to claim 1, wherein the image reading apparatus comprises:

3. the third attachment portion is attached to the reading unit and has an attachment surface parallel to the reading surface; the fourth mounting portion is attached to the hinge mounting member and has a mounting surface perpendicular to the reading surface; 3. The image reading apparatus according to claim 1, wherein the image reading apparatus is a digital camera.

4. the third attachment portion has a length that is 10% or more of a length of the reading unit in a direction perpendicular to a hinge axis of the hinge mechanism when viewed from a direction perpendicular to the reading surface; 4. The image reading apparatus according to claim 1, wherein the image reading apparatus is a scanning apparatus.

5. The third attachment portion is attached to a bottom surface of the reading unit.

5. The image reading apparatus according to claim 1, wherein the image reading apparatus is a digital camera.

6. the hinge mechanism has a biasing portion that generates a torque that is balanced with a torque due to the weight of the transport unit when the transport unit is opened beyond a predetermined angle, 6. The image reading apparatus according to claim 1, wherein the image reading apparatus is a digital camera.

7. an image forming unit that forms an image based on the image information read by the reading unit; a frame supporting the image forming unit, The hinge mounting member has a fifth mounting portion that is attached to the frame.

7. The image reading apparatus according to claim 1, wherein the image reading apparatus is a digital camera.

Images