JP2023088009A - Image reading device and image forming apparatus - Google Patents

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

The present invention relates to an image reading device and an image forming device.

Image reading apparatuses include those that are installed in image forming apparatuses such as facsimiles, copiers, and multifunction machines that have printer and scanner functions, and those that are used independently as image reading apparatuses. Such an image reading apparatus has a scanning type in which a document placed on a table is read by a moving optical system, in addition to a type in which the document is read by moving it with respect to a fixed reading optical system. In the latter type, a configuration is known in which a carriage having a reading element arranged in the main scanning direction is moved in the sub-scanning direction in a housing of a reading device that accommodates the carriage.

A configuration is known in which a flexible flat cable (FFC) (hereinafter referred to as a "flexible cable") is provided as a medium for exchanging carriage read signals and carriage drive power with the apparatus main body. One end of the flexible cable is fixed to the carriage, and the other end is fixed to the main body. The flexible cable is curved and moved between the main body and the contact glass, which is the original placing portion, in accordance with scanning. A device is known (see, for example, Patent Document 1).

An image reading apparatus designed to be compact in the height direction has a configuration in which a flexible cable contacts the contact glass. In this configuration, as the carriage reciprocates in the sub-scanning direction, the flexible cable frequently repeatedly contacts and separates from the contact glass. Repetition of such actions may damage the flexible cable, and static electricity generated by friction may cause the flexible cable to stick to the bottom surface of the contact glass, causing the moving optical scanning unit to entangle the flexible cable. There is Furthermore, dirt and dust from the flexible cable may adhere to the contact glass, interfering with reading. If the surface of the contact glass becomes dirty, noise will be mixed in the read signal, resulting in a significant deterioration in image quality.

On the other hand, Patent Literature 1 discloses a configuration in which separating means is provided to prevent the curved portion of the flexible cable from coming into contact with the contact glass.

In Patent Document 1, as means for separating the flexible cable and the contact glass, there is a configuration in which a shaft fixed to a plurality of locations of the flexible cable and rollers attached to both ends of the shaft are provided, and a flexible cable is placed in between to face each other. An arrangement is disclosed having two rollers, a connecting member for the rollers and a guide. However, since any separation means has a complicated structure, it leads to an increase in cost.

On the other hand, in order to prevent contact between the flexible cable and the contact glass, it is necessary to secure a distance between the two, leading to the problem of increasing the size of the image reading apparatus.
On the other hand, if it is possible to reduce the contact area and contact time without completely separating the flexible cable from the contact glass and reduce the generation of static electricity, the problems described above, especially the optical properties of the flexible cable, can be solved. It is thought that entanglement by the scanning unit can be prevented.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide an image reading apparatus capable of preventing the flexible cable from being caught in the optical scanning unit without increasing the size of the apparatus.

In order to solve the above problems, the image reading apparatus of the present invention includes: a contact glass as a reading surface of a document placed thereon; an image sensor that reads the document by moving the reading area of the contact glass; and the image sensor. an optical scanning unit having a carriage that holds a movably in the sub-scanning direction; one end connected to the optical scanning unit and the other end connected to a fixed portion on the inner bottom surface of a housing containing the optical scanning unit; and a flexible cable having a curved cross-sectional shape between the contact glass and the inner bottom surface of the housing, wherein the carriage has the flexible cable on the front side of the forward path in the sub-scanning direction. A holding portion for holding a cable is provided, and the flexible cable is positioned substantially at the center of the horizontal separation distance from the holding portion at the home position of the optical scanning unit to the fixed portion. A load member that is bent to form a concave portion is provided, and the load member is made of a material that is close to the material forming the surface of the flexible cable on the electrification line.

According to the present invention, it is possible to provide an image reading apparatus capable of preventing the flexible cable from being caught in the optical scanning unit without increasing the size of the apparatus.

1 is a schematic external view showing an example of an image forming apparatus according to an embodiment of the invention; FIG. 2 is an example of an image reading apparatus according to an embodiment of the present invention, and is a schematic configuration diagram of a scanning reading unit that constitutes the image forming apparatus of FIG. 1. FIG. FIG. 3 is a schematic cross-sectional view of the scanning reading unit of FIG. 2 taken along line XX; 4 is a partially enlarged view of FIG. 3; FIG. FIG. 4 is a schematic diagram showing an example of adjusting means for adjusting the length of a flexible cable;

An image reading apparatus and an image forming apparatus according to the present invention will be described below with reference to the drawings. In addition, the present invention is not limited to the embodiments shown below, and can be changed within the scope of those skilled in the art, such as other embodiments, additions, modifications, deletions, etc. is also included in the scope of the present invention as long as the functions and effects of the present invention are exhibited.

FIG. 1 is a schematic external view showing an embodiment of an image forming apparatus equipped with an image reading apparatus according to the present invention. An image scanner or the like may be applied as an image reading device to be described later, and an image forming device may be applied to a copier or a facsimile device having an image scanner, or a multifunction machine having a copier function and a facsimile function. It is also possible to

1, the image forming apparatus of this embodiment includes an image forming section 101, a scanning reading section 102 as an image reading apparatus according to the present invention, and an automatic document feeder (hereinafter also referred to as "ADF") 103. It is configured.
The ADF 103 is attached to the scanning reading unit 102 so as to be freely opened and closed via an opening and closing mechanism such as a hinge.

The image forming unit 101 constitutes image forming means, and includes an exposure device (not shown), a plurality of photosensitive drums, and different colors (cyan (C), yellow ( Y), magenta (M), and black (Bk) toners, a transfer belt, and a fixing device.

Based on the image information read by the scanning reading unit 102 and separated by color, images are formed on a plurality of photosensitive drums by color, and the toner on the photosensitive drums is applied to the recording paper supplied from the paper feeding unit. After superimposing and transferring, the toner of the toner image transferred to the recording paper is melted by the fixing device to fix the color image on the recording paper.

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

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

An electrical signal, which is read information, is sent from a board including a CCD attached to the optical scanning unit 16 to a body side board provided on the inner bottom side of the housing 4 through a cable. A flexible cable suitable for space saving is used as the cable.

ADF 103 shown in FIG. I have it. The ADF 103 also has a paper discharge section including various rollers, etc. 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.

The ADF 103 also functions as a document pressing portion that presses and fixes the document placed on 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 . It also has functions.
The contact glass 7 is provided on the upper portion of the housing 4 of the scanning reading section 102 and constitutes the upper surface of the housing 4 .

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

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

The carriage of the optical scanning unit 16 has a holding portion 22 that holds the flexible cable 30 on the front side of the outward path in the sub-scanning direction.
The flexible cable 30 is bent to form a concave portion 33 at a position 23 substantially in the center of the horizontal separation distance L2 from the holding portion 22 at the home position of the optical scanning unit 16 to the fixed portion 21 . It has a load member 24 . (In the figure, L3=L2/2.)

Since the flexible cable 30 has the load member 24 , the flexible cable 30 can be bent without being affected by the stiffness of the rising portion 31 from the fixed portion 21 , thereby forming the concave portion 33 . When the load member 24 is not provided, the area of the flexible cable 30 facing the contact glass 7 is generally convex, and comes into contact with the contact glass 7 over a wide range.
On the other hand, in the present embodiment, the concave portion 33 is formed substantially in the central portion of the convex portion, and two or more convex portions including the convex portions (32, 34) formed on both sides of the concave portion 33 are provided. A contact area between the cable 30 and the contact glass 7 is reduced.

In addition, it is preferable that the flexible cable 30 is arranged at a position that is invisible or difficult to be seen by the user. When the optical scanning unit 16 reciprocates in the sub-scanning direction B, the influence of contact of the flexible cable 30 with the contact glass 7 can be reduced.

The load member 24 is made of a material that is close to the material forming the surface of the flexible cable 30 on the electrification series. This can reduce or prevent the generation of static electricity.
Since the surface of the flexible cable 30 is generally covered with a material containing polyester, examples of materials for the load member 24 include polyester, polycarbonate, ABS resin, polystyrene, urethane resin, polypropylene, vinyl chloride resin, and silicone resin.

3 and 4, the load member 24 is provided on the top surface of the flexible cable 30 (the surface facing the contact glass 7). It may be provided on any surface of the flexible cable 30 as long as the concave portion 33 can be formed by bending in the direction of separation.
Moreover, the load member 24 may be detachably provided with respect to the flexible cable 30, or may be adhered and fixed with an adhesive or the like.

With such a configuration, it is possible to prevent the flexible cable 30 from being caught by the moving optical scanning unit 16 .

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

The load member 24 and the recess 33 of the flexible cable 30 formed by the load member 24 are displaced as the optical scanning unit 16 moves in the sub-scanning direction B without contacting the contact glass 7 and the inner bottom surface of the housing 4. is preferred.
If the concave portion 33 comes into contact with the inner bottom surface of the housing 4 , the flexible cable 30 may get caught under the moving optical scanning unit 16 . To prevent this, it is preferable to adjust the weight of the load member 24 and/or adjust the length of the flexible cable 30 .
In order to adjust the length of the flexible cable 30, for example, as shown in FIGS. It is possible to adopt an aspect in which an adjusting means 26 is provided.

5A and 5B are diagrams showing an example of adjusting means for adjusting the length of the flexible cable 30. FIG. 5A is a perspective view of a screw member (length adjusting screw) 26 as an example, and FIG. 4] is a perspective view showing an example of a state in which a flexible cable 30 is wound around a screw member. [FIG.

In this embodiment, the adjustment means is a screw member 26 that can wind the flexible cable 30 by rotation.
The screw member 26 has a screw portion 29 rotatably screwed into a screw hole (not shown) provided in the carriage, and a shaft portion 28 and a hook portion 27 for winding the flexible cable 30 .
FIG. 5B shows a state in which the flexible cable 30 is inserted through the screw member 26 as shown in the cross-sectional views of FIGS. By rotating the screw member 26 in this state, the flexible cable 30 can be wound up or unwound, and the length of the flexible cable 30 can be appropriately adjusted.

According to the image reading apparatus of this embodiment, the flexible cable 30 and the contact glass 7 can be separated from each other without increasing the size of the apparatus. can be prevented.

4 housing 7 contact glass 16 optical scanning unit 21 connection fixing part 22 holding part 23 load member 26 screw member (length adjusting screw)
27 Hook 28 Shaft 29 Screw 30 Flexible flat cable (FFC)
101 image forming unit 102 scanning reading unit (image reading device)
103 automatic document feeder (ADF)

JP-A-5-34838

Claims (8)

a contact glass that serves as a reading surface for the placed document;
an optical scanning unit having an image sensor that reads a document by moving the reading area of the contact glass, and a carriage that holds the image sensor movably in a sub-scanning direction;
One end is connected to the optical scanning unit, the other end is connected to a fixing portion on the inner bottom surface of a housing that accommodates the optical scanning unit, and the cross-sectional shape is curved between the contact glass and the inner bottom surface of the housing. An image reading device comprising: a flexible cable having
the carriage has a holding portion for holding the flexible cable on a surface that is the head side of the forward path in the sub-scanning direction;
The flexible cable has a load member that bends the flexible cable to form a concave portion at a position substantially at the center of the horizontal separation distance from the holding portion to the fixed portion at the home position of the optical scanning unit. have
The image reading apparatus according to claim 1, wherein the load member is made of a material that is close to a material forming the surface of the flexible cable on a charging line. 2. The image reading apparatus according to claim 1, wherein said flexible cable has two or more protrusions including both sides of said recess formed by said load member. 2. The image reading apparatus according to claim 1, wherein the fixed portion is arranged at a position substantially at the center of a scanning range of the optical scanning unit in the sub-scanning direction. The load member and the recess of the flexible cable formed by the load member are displaced as the optical scanning unit moves in the sub-scanning direction without contacting the contact glass and the inner bottom surface of the housing. 4. The image reading device according to any one of claims 1 to 3. 5. The image reading apparatus according to claim 1, wherein the carriage includes adjusting means for adjusting a length between the holding portion and the fixing portion of the flexible cable. 6. The image reading apparatus according to claim 5, wherein said adjustment means is a screw member capable of winding said flexible cable by rotation. The surface of the flexible cable is made of a material containing polyester,
7. The load member according to any one of claims 1 to 6, 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. Image reader. An image forming apparatus comprising the image reading apparatus according to claim 1 .

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