Image reading device and image forming device

Abstract

To provide an image reading device that can prevent a flexible cable from getting caught in an optical scanning unit, without causing increase in a size of the device.SOLUTION: An image reading device 102 comprises: a contact glass 7 that is a reading surface of a document placed thereon; an optical scanning unit 16; and a flexible cable 30 that is connected with the optical scanning unit 16 at one end and connected with a stationary part 21 at the other end, and has a curved cross-sectional shape between the contact glass 7 and an inner bottom face of a housing 4. In the image reading device 102, the flexible cable 30 has a load member 24 that bends the flexible cable 30 to form a concave part 33 at a position 23 that is substantially a middle of a clearance L2 in a horizontal direction from a holding part 22 at a home position of the optical scanning unit 16 to the stationary part 24, and the load member 24 is composed of a material at a position on a triboelectric series close to a position of a material constituting a surface of the flexible cable 30.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to an image reading device and an image forming device. [Background technology]

[0002] Image reading devices include those installed in image forming devices such as facsimiles, copiers, and multifunction devices that combine printer and scanner functions, as well as those used independently as image reading devices. Such image reading devices include those that read an original by moving it relative to a fixed reading optical system, and those that scan an original placed on a table using a moving optical system. The latter type of image reading device is known to have a configuration in which a carriage equipped with a reading element arranged in the main scanning direction is moved in the sub-scanning direction within the housing of the reading device that houses it.

[0003] A known configuration includes a flexible flat cable (FFC) (hereinafter referred to as "flexible cable") as a medium for transmitting and receiving carriage read signals and carriage drive power to and from the device main body. One end of the flexible cable is fixed to the carriage side, and the other end is fixed to the device main body, and the flexible cable is configured to bend and move between the contact glass, which is the document placement unit, and the device main body as scanning occurs (see, for example, Patent Document 1).

[0004] In image reading devices that are designed to be compact in height, the flexible cable is configured to contact the contact glass. In this configuration, the flexible cable frequently moves back and forth between the contact glass and the carriage as it moves back and forth in the sub-scanning direction. Repeated movements like this can damage the flexible cable. Static electricity generated by friction can cause the flexible cable to adhere to the bottom surface of the contact glass, potentially entangling the flexible cable in the moving optical scanning unit. Furthermore, dirt and dust from the flexible cable can adhere to the contact glass, potentially interfering with reading. A dirty contact glass surface can introduce noise into the reading signal, significantly reducing image quality.

[0005] In response to this, Patent Document 1 discloses a configuration in which a spacing means is provided to prevent the curved portion of the flexible cable from contacting the contact glass. Summary of the Invention [Problem to be solved by the invention]

[0006] Patent Document 1 discloses a structure having a shaft fixed to multiple points on the flexible cable and rollers attached to both ends of the shaft as a means for separating the flexible cable from the contact glass, and a structure having two rollers arranged opposite each other with the flexible cable in between, a connecting member for the rollers, and a guide. However, both of these separation means have complex structures, which leads to increased costs.

[0007] On the other hand, in order to prevent contact between the flexible cable and the contact glass, it is necessary to ensure a separation distance between the two, which leads to an increase in the size of the image reading device. In contrast, if the contact area and contact time can be reduced and the generation of static electricity can be reduced without completely separating the flexible cable from the contact glass, it is believed that the problems described above, particularly the flexible cable becoming entangled in the optical scanning unit, can be prevented.

[0008] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide an image reading device that can prevent a flexible cable from being entangled in an optical scanning unit without increasing the size of the device. [Means for solving the problem]

[0009] In order to solve the above-mentioned problems, the image reading device of the present invention includes a contact glass that is a reading surface of a document to be placed on it, an image sensor that moves across a reading area of ​​the contact glass to read the document, and an optical scanning unit having a carriage that holds the image sensor so that the image sensor can move in a sub-scanning direction, and a carriage having one end connected to the optical scanning unit and the other end connected to a fixing portion on the inner bottom surface of a housing that houses the optical scanning unit, and having a curved cross-sectional shape between the contact glass and the inner bottom surface of the housing. of and a flexible cable having a fixing portion, the carriage having a holding portion for holding the flexible cable on a surface at the front end of a forward path in a sub-scanning direction, the flexible cable being spaced a horizontal distance from the holding portion to the fixing portion at a home position of the optical scanning unit. Inside a load member at a central position that bends the flexible cable to form a recess, The surface of the flexible cable is made of a material containing polyester, and the load member is made of a material containing any of polyester, polycarbonate, ABS resin, polystyrene, urethane resin, polypropylene, vinyl chloride resin, and silicone resin. It is characterized by: [Effects of the Invention]

[0010] According to the present invention, it is possible to provide an image reading device that can prevent the flexible cable from getting entangled in the optical scanning unit without increasing the size of the device. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a schematic external view illustrating an example of an image forming apparatus according to an embodiment of the present invention. [Figure 2] 2 is an example of an image reading apparatus according to an embodiment of the present invention, and is a schematic diagram of a scanning and reading unit that constitutes the image forming apparatus of FIG. 1. FIG. [Figure 3] 2. FIG. 3 is a cross-sectional view of the scanning and reading unit taken along line XX in FIG. [Figure 4] FIG. 4 is a partially enlarged view of FIG. [Figure 5] 10A and 10B are schematic diagrams showing an example of an adjusting means for adjusting the length of a flexible cable. DETAILED DESCRIPTION OF THE INVENTION

[0012] The image reading device and image forming device of the present invention will be described below with reference to the drawings. Note that the present invention is not limited to the following embodiments, and other modifications, additions, corrections, deletions, and other changes can be made within the scope of what a person skilled in the art can conceive. Any aspect that achieves the functions and effects of the present invention is included in the scope of the present invention.

[0013] 1 is a schematic diagram showing an embodiment of an image forming apparatus equipped with an image reading device according to the present invention. Note that the image reading device described below may be applied to an image scanner or the like, and the image forming apparatus may be applied to a copying machine or facsimile machine having an image scanner, or even a multifunction machine having a copying function and a facsimile function.

[0014] In FIG. 1, the image forming apparatus of this embodiment includes an image forming unit 101, a scanning and reading unit 102 as an image reading device according to the present invention, and an automatic document feeder (hereinafter also referred to as "ADF") 103. The ADF 103 is attached to the scanning and reading unit 102 via an opening and closing mechanism such as a hinge so as to be able to open and close freely.

[0015] The image forming unit 101 constitutes an image forming means and includes an exposure device (not shown), a plurality of photosensitive drums, developing devices having toners of different colors (cyan (C), yellow (Y), magenta (M), black (Bk)) arranged around each photosensitive drum, a transfer belt, and a fixing device.

[0016] Based on the image information read by the scanning and reading unit 102 and separated by color, an image is formed on a plurality of photosensitive drums in different colors, and the toner on the photosensitive drums is superimposed and transferred onto recording paper supplied from a paper feed unit. After that, the toner of the toner image transferred onto the recording paper is melted by a fixing device, and the color image is fixed onto the recording paper.

[0017] FIG. 2 is an example of an image reading apparatus according to an embodiment of the present invention, and is a schematic diagram of the scanning and reading unit 102 that constitutes the image forming apparatus of FIG. As shown in FIG. 2, the image reading device (scanning unit) 102 of this embodiment includes a contact glass 7 that is the reading surface of a document placed thereon, and an optical scanning unit 16 in a housing 4.

[0018] The optical scanning unit 16 has an image sensor that reads the document by moving over the reading area W of the contact glass 7, and a carriage that holds the image sensor so that it can move in the sub-scanning direction (the direction of the arrow B in the figure). The main scanning direction of the image sensor is its longitudinal direction (the direction of the arrow A in the figure). Specifically, the optical scanning unit 16 holds an image sensor, a CCD (charge-coupled device), a light source, a lens, and a mirror, and is moved in the sub-scanning direction (direction B) by a driving means (not shown) to read a two-dimensional color image of a document placed on the contact glass 7.

[0019] The electrical signal representing the read information is sent via a cable from a board including a CCD attached to the optical scanning unit 16 to a main body board provided on the inside bottom side of the housing 4. A flexible cable suitable for space saving is used as the cable.

[0020] 1 includes, for example, a document tray and a paper feed section including various rollers that separate documents one by one from a stack of documents placed on the document tray and transport them toward the contact glass 7. The ADF 103 also includes a paper discharge section including various rollers, and the document on the contact glass 7 is read by the optical scanning unit 16 of the scanning reading section 102 and then discharged to a paper discharge tray.

[0021] The ADF 103 also functions as a document pressing section that presses and fixes the document against the contact glass 7 when the optical scanning unit 16 moves in the sub-scanning direction (direction B) to read the document placed on the contact glass 7. The contact glass 7 is provided on the upper part of the housing 4 of the scanning and reading unit 102 and forms the upper surface of the housing 4.

[0022] FIG. 3 is a schematic cross-sectional view of the scanning and reading unit 102 shown in FIG. 2 taken along line XX, and FIG. 4 is a partially enlarged view of FIG. The optical scanning unit 16 reads the document by moving in the sub-scanning direction from a predetermined home position (standby position) shown in FIGS.

[0023] As shown in FIGS. 3 and 4, a flexible cable 30 for power supply or signal transmission / reception is connected to the optical scanning unit 16. One end of the flexible cable 30 is connected to the substrate 17 of the optical scanning unit 16, and the other end is connected to a fixed portion 21 on the inner bottom surface of the housing 4 that houses the optical scanning unit 16, and has a curved cross-sectional shape between the contact glass 7 and the inner bottom surface of the housing 4. The fixed portion 21 is electrically connected to the main body side substrate provided in the housing 4.

[0024] The carriage of the optical scanning unit 16 has a holding portion 22 for holding a flexible cable 30 on the surface at the leading end of the forward path in the sub-scanning direction. The flexible cable 30 has a load member 24 that bends the flexible cable 30 to form a recess 33 at a position 23 that is approximately the center of the horizontal distance L2 from the holding portion 22 to the fixed portion 21 when the optical scanning unit 16 is in the home position. (In the drawing, L3 = L2 / 2.)

[0025] By including the load member 24, the flexible cable 30 can bend without being affected by the stiffness of the rising portion 31 rising from the fixed portion 21, and can form the recess 33. If the load member 24 were not provided, the area of ​​the flexible cable 30 facing the contact glass 7 would be convex as a whole, and would come into contact with the contact glass 7 over a wide area. In contrast, in this embodiment, a recess 33 is formed in approximately the center of the convex portion, and there are two or more convex portions including convex portions (32, 34) formed on both sides of the recess 33, thereby reducing the contact area between the flexible cable 30 and the contact glass 7.

[0026] It is preferable that the flexible cable 30 is arranged in a position that is not visible or difficult to see from the user, etc. When the optical scanning unit 16 moves back and forth in the sub-scanning direction B, the influence of the flexible cable 30 coming into contact with the contact glass 7 can be reduced.

[0027] The load member 24 is made of a material that is close in position in the triboelectric series to the material that forms the surface of the flexible cable 30. This makes it possible to reduce or prevent the generation of static electricity. Since the surface of the flexible cable 30 is generally covered with a material containing polyester, it is preferable that the material of the load member 24 be made of a material containing, for example, any of polyester, polycarbonate, ABS resin, polystyrene, urethane resin, polypropylene, vinyl chloride resin, and silicone resin.

[0028] In the examples of Figures 3 and 4, the load member 24 is provided on the upper surface of the flexible cable 30 (the surface facing the contact glass 7), but this is not limited to this and the load member 24 may be provided on any surface of the flexible cable 30 as long as the flexible cable 30 can be bent in a direction away from the contact glass 7 to form a recess 33. Furthermore, the load member 24 may be provided detachably with respect to the flexible cable 30, or may be adhesively fixed thereto with an adhesive or the like.

[0029] With this configuration, it is possible to prevent the flexible cable 30 from being entangled by the moving optical scanning unit 16.

[0030] The fixed portion 21 is preferably disposed at a position that is approximately the center of the scanning range L of the optical scanning unit 16 in the sub-scanning direction B. In this case, L2=L / 2 in FIGS.

[0031] It is preferable that the load member 24 and the recess 33 of the flexible cable 30 formed by the load member 24 displace as the optical scanning unit 16 moves in the sub-scanning direction B without coming into contact with the contact glass 7 and the inner bottom surface of the housing 4. If the recess 33 comes into contact with the inner bottom surface of the housing 4, the flexible cable 30 may become entangled under the moving optical scanning unit 16. To prevent this, it is preferable to adjust the weight of the load member 24 and / or the length of the flexible cable 30. In order to adjust the length of the flexible cable 30, for example, as shown in Figures 3 and 4, the carriage of the optical scanning unit 16 can be provided with an adjustment means 26 for adjusting the length between the holding portion 22 and the fixed portion 21 of the flexible cable 30.

[0032] Figure 5 shows an example of an adjustment means for adjusting the length of flexible cable 30, where Figure 5(A) is a perspective view of an example screw member (length adjustment screw) 26, and Figure 5(B) is a perspective view showing an example of the state in which flexible cable 30 is wound around the screw member.

[0033] In this embodiment, the adjustment means is a screw member 26 that can wind up the flexible cable 30 by rotating it. The screw member 26 has a threaded portion 29 that rotatably engages with a screw hole (not shown) provided in the carriage, a shaft portion 28 for winding up the flexible cable 30, and a hook portion 27. 3 and 4, Fig. 5(B) shows a state in which the flexible cable 30 is inserted into the screw member 26. By rotating the screw member 26 in this state, the flexible cable 30 can be wound or unwound, and the length of the flexible cable 30 can be adjusted as needed.

[0034] According to the image reading device of this embodiment, the device does not need to be enlarged in order to separate the flexible cable 30 from the contact glass 7, and the flexible cable 30 can be prevented from becoming entangled in the optical scanning unit 16 with a simple configuration. [Explanation of symbols]

[0035] 4. Cabinet 7. Contact Glass 16 Optical scanning unit 21 Connection fixing part 22 Holding part 23 Load member 26 Screw component (length adjustment screw) 27 Hook 28 Shaft 29 Threaded part 30 Flexible Flat Cable (FFC) 101 Image forming unit 102 Scanning and reading unit (image reading device) 103 Automatic Document Feeder (ADF) [Preliminary Technology Documents] [License]

[0036] [License 1] Special Announcement No. 5-34838

Claims

1. a contact glass that is the reading surface for the document to be placed on; an optical scanning unit having an image sensor that reads an original by moving over a reading area of ​​the contact glass, and a carriage that holds the image sensor so as to be movable in a sub-scanning direction; an image reading device comprising: a flexible cable having one end connected to the optical scanning unit and the other end connected to a fixing portion on an inner bottom surface of a housing that houses the optical scanning unit, the flexible cable having a curved cross-sectional shape between the contact glass and the inner bottom surface of the housing, the carriage has a holding portion for holding the flexible cable on a surface that is a leading side in the outward movement in the sub-scanning direction, the flexible cable has a load member that bends the flexible cable to form a recess at a position that is the center of a horizontal distance from the holding portion to the fixed portion when the optical scanning unit is in a home position, the surface of the flexible cable is made of a material containing polyester, 10. An image reading device, wherein the load member is made of a material containing any one of polyester, polycarbonate, ABS resin, polystyrene, urethane resin, polypropylene, vinyl chloride resin, and silicone resin.

2. 2. The image reading device according to claim 1, wherein the flexible cable has two or more protrusions, including two protrusions on both sides of the recess formed by the load member.

3. 2. The image reading device according to claim 1, wherein the fixed portion is disposed at a position that is the center of a scanning range in the sub-scanning direction of the optical scanning unit.

4. An image reading device as described in any one of claims 1 to 3, characterized in that the load member and the recess of the flexible cable formed by the load member displace as the optical scanning unit moves in the sub-scanning direction without contacting the contact glass and the inner bottom surface of the housing.

5. 5. The image reading device according to claim 1, wherein the carriage includes an adjustment unit for adjusting the length of the flexible cable between the holding portion and the fixed portion.

6. 6. The image reading apparatus according to claim 5, wherein the adjusting means is a screw member that can wind up the flexible cable by rotating it.

7. An image forming apparatus comprising the image reading device according to any one of claims 1 to 6.

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