Image reading unit, image reading device, and image forming device

Abstract

To provide an image reading unit, an image reading device and an image formation apparatus which suppress the number of components while securing the assemblability in a case of attaching an image sensor to a holding member.SOLUTION: A carriage 320 of an image reading unit 300 includes a hole part 321 to which a first protrusion part 313a of an image sensor 310 is fit and a concave-shaped first groove part 322 to which a second protrusion part 313b of the image sensor 310 is fit. The image reading unit 300 includes a falling prevention member 300 which is attached to the first groove part 322 of the carriage 320 and prevents the second protrusion part 313b from falling from the first groove part.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to an image reading unit that reads an image of a document, an image reading device that reads an image of a document, and an image forming device that forms an image on a recording medium. [Background technology]

[0002] Conventionally, image forming apparatuses such as copiers and facsimiles are known that include an image reading device that optically reads an image on a document. Among the image reading units used in such image reading devices, there is one that includes a holding member that holds an image sensor having a plurality of light receiving elements. The image reading unit described in Patent Document 1 is positioned in the sub-scanning direction of the image sensor by fitting protrusions provided on both sides of the image sensor in the main scanning direction into two recesses provided in the holding member.

[0003] Furthermore, since the fitting portion into which the protruding portion of the image sensor is fitted has a concave shape, when the image sensor is attached to the holding member, it is possible to insert the protruding portion through the notch of the concave shape. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-150311 Summary of the Invention [Problem to be solved by the invention]

[0005] In the above configuration, it is preferable to provide a retaining member to prevent the protrusion of the image sensor from slipping out of the recessed cutout. However, if the fitting portions into which the two protrusions on both sides of the image sensor fit are both recessed, two retaining members are required, which increases the number of parts, leading to increased costs and reduced assembly. On the other hand, if the fitting portions into which the two protrusions on the image sensor fit are both holes without cutouts, it becomes difficult to fit one protrusion into the other protrusion into the fitting portion of the holding member after fitting the other protrusion, reducing assembly.

[0006] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide an image reading unit, an image reading device, and an image forming apparatus that reduce the number of parts while ensuring ease of assembly when attaching an image sensor to a holding member. [Means for solving the problem]

[0007] an image sensor for reading an image of a document, the image sensor having a plurality of light receiving elements arranged in a main scanning direction, a first protruding portion provided at one end in the main scanning direction and protruding in the main scanning direction, and a second protruding portion provided at the other end in the main scanning direction and protruding in the main scanning direction; a first fitting portion which is a hole having a continuous inner edge into which the first protruding portion fits, and a second fitting portion having a recessed shape into which the second protruding portion fits; And, a retaining member that retains the image sensor; and a retaining member that is attached to the second fitting portion of the retaining member and that prevents the second protrusion from coming out of the concave cutout portion of the second fitting portion, and the image sensor includes: The first protrusion The first fitting portion and the second protrusion is The second fitting portion To be fitted into By , perpendicular to the main scanning direction Movement in the sub-scanning direction is restricted, the retaining member has a claw portion, the holding member has an engaging portion with which the claw portion engages, and the engagement of the claw portion with the engaging portion restricts movement of the retaining member in the main scanning direction; An image reading unit characterized by: [Effects of the Invention]

[0008] According to the present invention, it is possible to provide an image reading unit, an image reading device, and an image forming device that reduce the number of parts while ensuring ease of assembly when attaching an image sensor to a holding member. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a front view of an image forming apparatus according to an embodiment of the present invention. [Figure 2] FIG. 1 is a perspective view of an image reading apparatus according to an embodiment of the present invention. [Figure 3] FIG. 2 is a perspective view of the image reading device with the ADF open. [Figure 4] FIG. 1 is a cross-sectional view of an image reading apparatus according to an embodiment of the present invention. [Figure 5] FIG. 2 is a top view of the image reading unit according to the embodiment. [Figure 6] 2 is a schematic cross-sectional view of the image reading unit according to the embodiment. [Figure 7] FIG. 10 is a diagram showing how to attach the image sensor and carriage. [Figure 8] FIG. 2 is a perspective view showing a retaining member according to the embodiment. [Figure 9] FIG. 2 is a perspective view of an image reading unit according to the embodiment. [Figure 10] FIG. 2 is a perspective view of the image reading unit with an image sensor cover removed. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. However, the following embodiments are merely examples of the present invention and are not intended to limit the technical scope of the present invention.

[0011] [Image forming device] First, a schematic configuration of an image forming apparatus 101 according to this embodiment will be described with reference to Fig. 1. Note that the image forming apparatus 101 is merely one example of a configuration to which the present invention is applied, and a facsimile machine, inkjet printer, multifunction peripheral, etc., equipped with an image reading device 103 also fall under the category of image forming apparatuses according to the present invention.

[0012] 1, an image forming apparatus 101 is composed of an apparatus main body 102 and an image reading device 103 that is attached to the top of the apparatus main body 102 and that reads an image of a document. The image reading device 103 has a reader 30 that reads an image of a document, and an automatic document feeder (hereinafter referred to as ADF) 1 that transports the document.

[0013] The device main body 102 has an image forming means for forming an image on a sheet, which is a recording medium, and below that a paper feeding means for feeding the sheets, which includes a paper feeding cassette 104. The device main body 102 also has a paper discharge section 105 for discharging and stacking sheets on which an image has been formed by the image forming means. The device main body 102 and the image reading device 103 are connected by a cable, and the device main body 102 can form an image on a sheet based on image data of a document read by the image reading device 103.

[0014] In the apparatus main body 102, the image forming means is configured as a print engine using a conventionally known electrophotographic method, and includes a laser writing unit, an electrophotographic processing unit, a fixing unit, etc. (not shown). The paper feeding means includes a paper feeding roller (not shown) and other components for separating and feeding sheets placed in a paper feeding cassette 104, and supplies sheets to the image forming means in the apparatus main body 102.

[0015] [Image reader] Next, the image reading device 103 will be described with reference to Fig. 2 to Fig. 4. Fig. 2 is a perspective view of the image reading device 103. Fig. 3 is a perspective view of the image reading device 103 in a state where the ADF 1 is opened relative to the reader 30. Fig. 4 is a cross-sectional view of the image reading device 103.

[0016] As shown in Fig. 4, the reader 30 has a first image reading unit 300 that reads images from documents D1 and D2. Also, on the top surface of the reader 30, there are provided a transparent first flow reading glass 212 that transmits visible light, and a transparent document table glass 213 that is arranged alongside the first flow reading glass 212 in the sub-scanning direction (the direction of arrow T in Fig. 4). The first image reading unit 300 is movable in the sub-scanning direction by a drive belt 250, and reads an image of document D1 placed on the document table glass 213. The first image reading unit 300 also reads an image of the first side (front side) of document D2 that is transported by the ADF 1 at a first reading position F1.

[0017] The ADF1 has a second image reading unit 400 that reads an image from the second side (rear side) of the original D2. The second image reading unit 400 reads an image of the second side of the original D2 transported by the ADF1 at a second reading position F2 downstream of the first reading position F1 in the transport direction of the original D2. The first image reading unit 300 and the second image reading unit 400 are made up of contact image sensors (hereinafter referred to as CIS), which are scanning devices with an equal-magnification optical system. The first image reading unit 300 and the second image reading unit 400 are equipped with a light source consisting of an LED array arranged in a main scanning direction perpendicular to the transport direction of the original D, and a plurality of light receiving elements 312 (see FIG. 5 described later) also arranged in the main scanning direction. Here, the main scanning direction is a direction perpendicular to the sub-scanning direction.

[0018] The ADF 1 is supported by hinges 5a and 5b to be able to open and close (rotate) in the vertical direction relative to the reader 30 so that the document glass 213 can be opened. That is, when the ADF 1 is rotated upward and open, the user can access the document glass 213 to place or remove the document D1. Furthermore, when the ADF 1 is closed, the resin plate 4 is configured to press the document D1 placed on the document glass 213 so that the document D1 does not move.

[0019] The ADF 1 includes a document stacking tray 2 on which documents D2 are stacked, a document transport unit 222 that transports the documents D2 stacked on the document stacking tray 2, and a document discharge unit 3 on which the documents D2 are discharged and stacked. The document transport unit 222 includes a document feed roller 231 that feeds the documents D2 stacked on the document stacking tray 2, a separation roller pair 232 that separates the documents D2 one by one, and a first transport roller pair 233 that pulls out the separated documents D2. The document transport unit 222 also includes multiple transport roller pairs that sequentially transfer and transport the documents D2 received from the first transport roller pair 233. That is, the documents D2 separated from the other documents by the separation roller pair 232 are transported in order by the first transport roller pair 233, the second transport roller pair 234, the third transport roller pair 235, the fourth transport roller pair 236, the fifth transport roller pair 238, and the sixth transport roller pair 240. These pairs of conveying rollers are examples of sheet conveying means that convey a sheet serving as an original in the sheet conveying direction.

[0020] A pair of discharge rollers 241 is disposed downstream of the sixth pair of conveying rollers 240, which discharges the document D2, from which the image has been read, to the document discharge section 3. The document discharge section 3 is disposed at a position overlapping the document stacking tray 2 when viewed from above, and the document conveying section 222 conveys the document D2 via a document conveying path 242 curved in a U-shape.

[0021] The document transport unit 222 includes a first platen roller 237 located between the fourth transport roller pair 236 and the fifth transport roller pair 238 and facing the first flow reading glass 212. The first platen roller 237 is a roller member that rotates in contact with the second side of the document D2, thereby preventing the document D2 from lifting up from the first flow reading glass 212. The document transport unit 222 also includes a second platen roller 239 located between the fifth transport roller pair 238 and the sixth transport roller pair 240 and facing the second flow reading glass 214. The second platen roller 239 is a roller member that rotates in contact with the first side of the document D2, thereby preventing the document D2 from lifting up from the second flow reading glass 214.

[0022] Next, an image reading operation by the image reading device 103 will be described. The image reading device 103 can execute a fixed reading mode in which an image of an original fixed on the platen glass 213 is read, and a flow reading mode in which an image of the original is read while the original is being transported by the ADF 1. In the fixed reading mode, the first image reading unit 300 moves in advance to a standby position P2. Then, the first image reading unit 300 scans the original placed on the platen glass 213 while moving back and forth between the standby position P2 and a terminal position P3 in the sub-scanning direction, thereby reading the original image.

[0023] In the flow reading mode, the first image reading unit 300 is positioned at the flow reading position P1 in accordance with the first reading position F1. In this state, the original D2 placed on the original stacking tray 2 is fed by the original feeding roller 231 and separated one by one at the separation nip portion of the separation roller pair 232. The separated original D2 is pulled out by the first conveyance roller pair 233, and then passes through the second conveyance roller pair 234, the third conveyance roller pair 235, and the fourth conveyance roller pair 236 to reach the first reading position F1. Then, at the first reading position F1, the first image reading unit 300 optically scans the first side of the original D2, and the image on the first side is read.

[0024] Original document D2 that has passed through first reading position F1 reaches second reading position F2 via fifth conveyance roller pair 238. Then, at second reading position F2, second image reading unit 400 optically scans the second side of original document D2, and the image on the second side is read. Original document D2 that has passed second reading position F2 passes through sixth conveyance roller pair 240 and is discharged to original discharge section 3 by discharge roller pair 241. This reading operation is repeated for each original document until a sensor provided in original stacking tray 2 confirms that all of the original documents have been fed.

[0025] [First image reading unit] Next, the configuration of the first image reading unit 300 will be described with reference to Fig. 5 to Fig. 8. Fig. 5 is a top view of the first image reading unit 300, and Fig. 6 is a schematic cross-sectional view of the first image reading unit 300. Figs. 7 and 8 are perspective views showing the process of assembling the first image reading unit 300.

[0026] The first image reading unit 300 includes an image sensor 310 and a carriage 320. The image sensor 310 is common to both the first image reading unit 300 and the second image reading unit 400. The image sensor 310 includes a housing 311 and a plurality of light receiving elements 312 housed in the housing 311 and arranged in the main scanning direction. To maintain a constant distance between the light receiving elements and the image reading surface, springs 326a and 326b are provided as urging members between the image sensor 310 and the carriage 320. As shown in FIG. 6, the springs 326a and 326b are each disposed on one side of the first image reading unit in the main scanning direction and press the image sensor 310 toward the platen glass 213 (upward in FIG. 6). In other words, the springs 326a and 326b urge the image sensor 310 in a direction perpendicular to both the main scanning direction and the sub-scanning direction (hereinafter referred to as the up-down direction).

[0027] The housing 311 of the image sensor 310 has a first protrusion 313a and a second protrusion 313b protruding in the main scanning direction on both side surfaces in the main scanning direction. The first protrusion 313a is formed at one end of the image sensor 310 in the main scanning direction, and the second protrusion 313b is formed at the other end of the image sensor 310. The first protrusion 313a and the second protrusion 313b are formed on an extension line of the multiple light receiving elements 312 arranged in the main scanning direction. In addition, the housing 311 has a third protrusion 314 protruding in the sub-scanning direction on its side surface in the sub-scanning direction. The third protrusion 314 is formed on the side where the first protrusion is provided in the main scanning direction.

[0028] The carriage 320 has a hole 321, which is a first fitting portion into which the first protrusion 313a fits, and a first groove 322, which is a second fitting portion into which the second protrusion 313b fits. The hole 321 and the first groove 322 are each formed on the side surface of the carriage 320 at the end in the main scanning direction. The hole 321 is a hole having a continuous rectangular inner edge that is long in the vertical direction. The first groove 322 is a concave shape with a notch 322a formed on the upper side in the vertical direction (on the platen glass 213 side). In other words, unlike the first groove 322, the hole 321 is a fitting portion that does not have a notch. Furthermore, the carriage 320 has a second groove 323 (see FIG. 5), which is a third fitting portion into which the third protrusion 314 fits, formed on the inside of the side surface in the sub-scanning direction.

[0029] In the first image reading unit 300, the image sensor 310 is positioned in the main scanning direction by fitting the third protrusion 314 into the second groove 323. Meanwhile, the image sensor 310 is positioned in the sub-scanning direction by fitting the first protrusion 313a and the second protrusion 313b into the hole 321 and the first groove 322, respectively. That is, the movement of the image sensor 310 in the sub-scanning direction is restricted by the hole 321 and the first groove 322, and the movement of the image sensor 310 in the main scanning direction is restricted by the second groove 323.

[0030] 7, the image sensor 310 is tilted and the first protrusion 313a is inserted into the hole 321, and then the second protrusion 313b on the opposite side is fitted into the first groove 322. At this time, the second protrusion 313b is inserted into the first groove 322 through the notch 322a of the first groove 322.

[0031] The first image reading unit 300 has a retaining member 330 that prevents the second protrusion 313b from coming out of the notch 322a of the first groove 322. The retaining member 330 has an abutment surface 331 against which the second protrusion 313b abuts. As described above, the image sensor 310 is biased upward by the springs 326a and 326b. Therefore, the second protrusion 313b moves in a direction that would cause it to come out of the notch 322a of the first groove 322, but the second protrusion 313b comes into contact with the abutment surface 331 of the retaining member 330, thereby preventing the second protrusion 313b from coming out of the notch 322a.

[0032] Furthermore, retaining member 330 has claw portions 332a and 332b, and carriage 320 has engaging portions 325a and 325b with which claw portions 332a and 332b engage, respectively. Claw portions 332a and 332b are formed on the inside of both side surfaces of retaining member 330 in the sub-scanning direction, protruding in the sub-scanning direction. Engagement portions 325a and 325b are formed so as to be recessed in the sub-scanning direction at positions corresponding to claw portions 332a and 332b on the side surfaces of carriage 320 where first groove portion 322 is formed.

[0033] Furthermore, the retaining member 330 has flat surfaces 333a and 333b, and the carriage 320 has a contact portion 324 that contacts the flat surfaces 333a and 333b. The flat surfaces 333a and 333b are flat surfaces that are parallel to both the main scanning direction and the sub-scanning direction. The contact portion 324 is formed in the first groove portion 322. The contact portion 324 has flat surfaces that sandwich the flat surfaces 333a and 333b when the retaining member 330 is attached to the carriage 320.

[0034] When attaching the retaining member 330 to the carriage 320, the retaining member 330 is moved in the main scanning direction (the direction of the arrow in FIG. 8 ). At this time, the claws 332a and 332b come into contact with the engagement portions 325a and 325b, causing the side surfaces of the retaining member 330 on which the claws 332a and 332b are formed to elastically deform outward. The claws 332a and 332b then engage with the engagement portions 325a and 325b, fixing the retaining member 330 so that it does not move in the main scanning direction. In other words, the retaining member 330 is attached to the carriage 320 by a snap-fit ​​configuration. Furthermore, when attaching the retaining member 330 to the carriage 320, the flat portions 333a and 333b are inserted into the abutment portions 324, fixing the retaining member 330 so that it does not move in the vertical direction.

[0035] [Second image reading unit] Next, the second image reading unit 400 will be described with reference to FIGS. 9 and 10. FIG. 9 is a perspective view of the second image reading unit 400 provided inside the ADF 1, and FIG. 10 is a perspective view of the second image reading unit 400 with the image sensor cover 402 removed. The second image reading unit 400 has an image sensor 310 similar to that of the first image reading unit 300. The second image reading unit 400 also has a second flow reading glass 214, an image sensor holder 401 that holds the image sensor 310, and an image sensor cover 402 that holds the second flow reading glass 214. At both ends of the image sensor holder 401, there are formed holes (not shown) having a shape similar to that of the hole 321, and a third groove 422 having a shape similar to that of the first groove 322. In addition, a groove (not shown) into which the third protrusion 314 fits is formed on the inner side surface of the image sensor holder 401 in the sub-scanning direction.

[0036] In the second image reading unit 400, the image sensor 310 is also positioned by fitting the first protrusion 313a, the second protrusion 313b, and the third protrusion 314 into the corresponding fitting portions. The second image reading unit 400 also has a retaining member 330 similar to that of the first image reading unit 300, and the retaining member 330 is attached to the third groove 422 to prevent the second protrusion 313b from coming out of the third groove 422.

[0037] In this embodiment, the image sensors 310 of the first image reading unit 300 and the second image reading unit 400 have a first protrusion 313a at one end in the main scanning direction that fits into a hole, and a second protrusion 313b at the other end that fits into a concave groove (first groove 322, third groove 422). Furthermore, the first image reading unit 300 and the second image reading unit 400 have a retaining member 330 that prevents the second protrusion 313b from coming out of the groove. This improves the ease of assembly of the first image reading unit 300 and the second image reading unit 400, and only one retaining member 330 is required for each image reading unit, thereby reducing the number of parts.

[0038] Furthermore, in this embodiment, the retaining member 330 is attached to the holding member (carriage 320, image sensor holder 401) in a snap-fit ​​configuration, which improves the ease of assembly when attaching the retaining member 330.

[0039] In the present embodiment, the image reading device 103 is exemplified as having a configuration including the reader 30 and the ADF 1, but the image reading device 103 may be configured without the ADF 1. In this case, a document pressing member for pressing down the document D1 placed on the document table glass 213 is provided rotatably relative to the reader 30. [Explanation of symbols]

[0040] 101 Image forming device 103 Image reading device 300 First image reading unit 400 Second image reading unit 310 Image Sensor 313a 1st protrusion 313b Second protrusion 314 Third protrusion 320 Carriage 330 Anti-slip member

Claims

1. an image sensor that reads an image of a document, the image sensor having a plurality of light receiving elements arranged in a main scanning direction, a first protruding portion provided at one end in the main scanning direction and protruding in the main scanning direction, and a second protruding portion provided at the other end in the main scanning direction and protruding in the main scanning direction; a holding member for holding the image sensor, the holding member having a first fitting portion which is a hole having a continuous inner edge into which the first protrusion fits, and a second fitting portion having a recessed shape into which the second protrusion fits; a retaining member attached to the second fitting portion of the holding member and configured to prevent the second protrusion from coming out of the recessed notch of the second fitting portion; Equipped with the first protruding portion is fitted into the first fitting portion, and the second protruding portion is fitted into the second fitting portion, so that movement of the image sensor in a sub-scanning direction perpendicular to the main scanning direction is restricted; The retaining member has a claw portion, the holding member has an engaging portion with which the claw portion engages, The claw portion engages with the engaging portion, thereby restricting movement of the retaining member in the main scanning direction. An image reading unit characterized by:

2. The image sensor has a third protrusion protruding in the sub-scanning direction, the holding member has a third fitting portion into which the third protrusion fits, The third protrusion is fitted into the third fitting portion, thereby restricting movement of the image sensor in the main scanning direction.

2. The image reading unit according to claim 1, wherein the image reading unit is a scanning unit.

3. the retaining member has a flat surface that is parallel to the main scanning direction and the sub-scanning direction, the second fitting portion has contact portions that contact both sides of the flat portion in a direction perpendicular to the main scanning direction and the sub-scanning direction, When the flat portion abuts against the abutting portion, movement of the retaining member in a direction perpendicular to the main scanning direction and the sub-scanning direction is restricted.

2. The image reading unit according to claim 1, wherein the image reading unit is a scanning unit.

4. a biasing member that biases the image sensor in a direction perpendicular to the main scanning direction and the sub-scanning direction; 4. The image reading unit according to claim 1, wherein the image reading unit is a scanning unit.

5. An image reading unit according to any one of claims 1 to 4; a transparent document table on which a document is placed, the holding member is movable along the document table in the sub-scanning direction, the image reading unit reads an image of a document placed on the document table while moving in the sub-scanning direction; An image reading device characterized by:

6. An image reading unit according to any one of claims 1 to 4; a document transport unit that transports a document, the holding member is fixed inside the document transport unit, the image reading unit reads an image of the document transported in the sub-scanning direction by the document transport unit; An image reading device characterized by:

7. The image reading device according to claim 5 or 6, and an image forming unit that forms an image on a recording medium based on the image of the document read by the image reading unit. An image forming apparatus characterized by:

Images