JP2009205107A - Image reader - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a cable connected to a reading unit from coming into contact with an original platen during reading operation. <P>SOLUTION: In the image reader, which includes: a unit moving in a movement direction along the original platen when the image of an original placed on the original platen is read; and the cable electrically connecting the unit and an electric substrate, the cable is arranged so as to extend over an original placing area and an area outside from the original placing area in a direction orthogonal to the movement direction and in a direction along the original platen, and a contact prevention member for preventing the cable from coming into contact with the original platen is provided in the area outside from the original placing area. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an image reading apparatus used for a copying machine, a facsimile, an image scanner, and the like.

  2. Description of the Related Art Conventionally, image reading apparatuses such as copiers, facsimiles, and image scanners are provided with a scanner carriage that moves inside a frame having an original platen glass disposed on the upper surface, and moves an original placed on the platen glass. It scans and reads the image of the document.

  As the scanner carriage, a contact type image sensor or an integrated carriage with a charge coupled device (CCD), mirror, imaging element, light source, etc. integrated is used, and the scanned image is transferred to the signal processing unit as an electrical signal. To do. A flat flexible cable (FFC) is used as a device for transmitting an electrical signal from the scanner carriage to the signal processing unit. If the FFC comes into contact with the platen glass during the scanning operation, the platen glass may become dirty or scratched, which may deteriorate the quality of the read image.

  Japanese Patent Application Laid-Open No. 2004-228561 describes a method for preventing dirt and scratches on the platen glass that is generated when the FFC contacts the platen glass during a scanning operation. The method is a method in which the flat portion of the FFC is arranged so as to be perpendicular to the platen glass, and the FFC and the platen glass are not in contact with each other or the portion in contact is minimized.

Further, Patent Document 2 discloses a method in which an FFC is provided with a weight and the FFC is bent to make it difficult for the FFC and the document glass to come into contact with each other.
JP2001-346006 JP 2004-273435 A

  However, these conventional methods have the following problems.

  In the method of disposing the flat portion of the FFC in Patent Document 1 so as to be perpendicular to the platen glass, the FFC is bent in the depth direction of the image reading apparatus, so that the size of the apparatus in the depth direction is secured in order to ensure a space to be bent. Will increase. Further, when the number of signals to be transmitted is increased and the width of the FFC is increased, the height of the apparatus is increased.

  In the method of bending the FFC with a weight in the FFC of Patent Document 2, the deflection due to the weight is reduced due to variations in the stiffness of the FFC or changes in the stiffness due to changes in the ambient temperature, and the FFC is placed on the platen glass. There is a possibility of contact. Further, when the weight is attached to the FFC, a sharp bend occurs, and there is a possibility that the FFC may be disconnected when repeated scanning is performed.

  SUMMARY OF THE INVENTION An object of the present invention is to prevent the document table from being stained or scratched by a cable with a small and simple configuration.

  The above object is achieved by the following image reading apparatus.

An original platen on which an original is placed in the original placement area;
A unit that moves in a moving direction along the document table when reading an image of the document;
A cable for electrically connecting the unit and the electrical board;
In an image reading apparatus having
The cable is disposed so as to straddle the document placement region and a region outside the document placement region in a direction perpendicular to the moving direction and along the document table.
In the image reading apparatus, a contact prevention member for preventing the cable and the document table from contacting each other is provided in an area outside the document placement area.

  According to the present invention, it is possible to prevent the document table from being stained or scratched by a cable with a small and simple configuration.

  Hereinafter, the image forming apparatus according to the present invention will be described in more detail with reference to the drawings.

Example 1
A first embodiment of an image reading apparatus and an image forming apparatus according to the present invention will be described with reference to FIGS.

  In FIG. 1, reference numeral 1 denotes a frame of an image reading apparatus, 2 denotes a platen glass on which a document is placed in a document placement region, and 3 denotes a unit that moves in the reading direction along the document table when reading an image of the document. This is the scanner carriage. Reference numeral 4 denotes a guide shaft for guiding the scanner carriage when the scanner carriage moves. The scanner carriage 3 has light sources 5 and 6 for illuminating the original, folding mirrors 7, 8 and 9 for guiding reflected light from the original, a lens 10 for imaging light, and photoelectrically converting the received light. A CCD (charge coupled device) 11 that reads as an electric signal is mounted. Here, the mirror and the lens correspond to an optical member, and the CCD corresponds to a photoelectric conversion element. The frame 1 is provided with an electrical board 12 having a power source for supplying power to the light sources 5 and 6 and the CCD 11 and a signal processing unit for processing a signal read by the CCD 11. The CCD 11 and the electrical board 12 are electrically connected by a flat flexible cable (FFC) 13 for transmitting signals. Reference numeral 14 denotes a contact preventing member provided on the lower surface of the original table glass in order to prevent the FFC from contacting the original table glass, and reference numeral 15 denotes an original placed on the original table glass 2.

  FIG. 5 is a top view of the image reading apparatus shown in FIG. The document table glass 2 is provided with a document placement area in which a placed document can be read. The document table glass 2 is provided with a sub-scanning size label 16 and a main scanning size label 17 for indicating the document placement position in an area outside the document placement area. Here, the sub-scanning direction refers to a moving direction in which the reading unit 3 moves when performing image reading. The main scanning direction is a direction orthogonal to the moving direction and along the document table. As shown in FIG. 5, the contact preventing member 14 is disposed on the lower surface of the document table glass 2 and under the sub-scanning size label 16. Therefore, the contact preventing member 14 is provided in a region outside the document placement region, and thus does not affect the reading of the document.

  FIG. 6 is a cross-sectional view of the image reading apparatus of FIG. 1 when viewed from the direction A in the drawing. The scanner carriage 3 is guided by the guide shaft 4 and the guide rail 18. The width of the FFC 13 is approximately the same as the width of the sub-scanning size label 16 or thicker than the sub-scanning size label 16. The position of the FFC 13 in the main scanning direction is such that at least a part of the FFC 13 passes under the contact prevention member 14 provided under the sub-scanning size label 16 and a part passes under the document placement area. It has become. That is, the FFC 13 is disposed so as to straddle the document placement area and the area outside the document placement area in a direction orthogonal to the moving direction and along the document table.

  In this embodiment, the contact preventing member 14 is provided so as to come into contact with an area closer to the document placement area than the center C of the width in the main scanning direction of the FFC 13. With this configuration, it is possible to effectively prevent the FFC 13 from falling to the original placement area side and coming into contact with the original table glass 2.

  FIG. 7 shows the arrangement of the drive system when the image reading apparatus of FIG. 1 is viewed from above. Reference numeral 19 denotes a motor for driving the scanner carriage 3, 20 and 21 denote wires for pulling the scanner carriage, and a part of the wires is fixed to the scanner carriage 3. 22 and 23 are winding pulleys for winding the wire, and 24 is a drive shaft that rotatably supports the winding pulley.

  When reading an image of a document with such a configuration, power is turned on by supplying power from the electrical board 12 to the light source 6 to illuminate the document 15 placed on the platen glass 2. The reflected light diffused by the document 15 is guided to the folding mirrors 7, 8, and 9 and imaged on the CCD 11 by the lens 10. The CCD 11 is driven by power supplied from the electrical board 12 and photoelectrically converts the light imaged by the lens 10 and reads it as an electrical signal. The electrical board 12 receives the image signal through the FFC 13.

  When the motor 19 is rotated, the take-up pulleys 22 and 23 are rotated together with the drive shaft 24 to take up the wires 20 and 21. As the wires 21 and 22 are wound up, the scanner carriage 3 moves at a predetermined speed in the sub-scanning direction (left-right direction in the figure) to scan the document. The image signal transmitted from the CCD 11 along with the scanning operation of the scanner carriage 3 is processed by the signal processing unit included in the electrical board 12 so that the image of the document 15 can be read electrically.

  The FFC 113 changes its curved state as shown in FIG. 2 → FIG. 3 → FIG. As shown in FIGS. 3 and 4, the FFC 13 is curved in a direction in contact with the platen glass 2 due to the rigidity of the FFC 13 itself. However, since the contact prevention member 14 is provided on the lower surface of the platen glass 2, the FFC 13 There is no direct contact with the platen glass 2.

  The material of the contact preventing member 14 is required to have a small load on the FFC 13 when sliding on the FFC 13. Therefore, a sheet material (low friction member) having a low coefficient of friction is applied to a foam sponge (elastic member) having low rigidity and high elasticity so that the pressure of the FFC 13 that changes depending on the bending state can be dispersed and received over as wide an area as possible. It is good to adopt a laminated structure. The low friction member is provided on the elastic member on the side in contact with the FFC 13. As an example of the material of the contact prevention member 14, for example, a foamed urethane laminated with a sheet of tetrafluoroethylene resin (PTFE) is suitable, but the material is not limited to this. Further, depending on the material, rigidity, and slidability of the FFC 13, other materials such as a resin plate having high slidability and rubber can be selected.

  In the above-described embodiment, the configuration in which the contact prevention member 14 is provided so as to be in contact with the document placement region side of the center of the width of the FFC 13 in the main scanning direction has been described. However, if a configuration that can sufficiently secure the width and height of the contact prevention member 14 can be taken, the contact prevention member 14 can be provided at the approximate center in the width direction of the FFC 13 or the side away from the document placement area. It becomes.

  In the present embodiment, a configuration in which an integrated carriage in which a charge coupled device (CCD), a mirror, an imaging element, a light source and the like are integrated is described as the scan carriage. However, even when a contact image sensor is used as the scan carriage, the same effect as described in this embodiment can be obtained.

  The method of driving the scan carriage is not limited to the method using the wire described in the present embodiment, and the same effect can be obtained by a method of driving with an endless belt.

(Example 2)
A second embodiment of the present invention will be described with reference to FIG.

  In the present embodiment, a first scanning body having an electric coupling element (CCD) fixed on an image reading device frame, a light source and one folding mirror, and a second scanning body having two folding mirrors. However, the application of the present invention to an image reading apparatus that scans a document at a speed ratio of 2: 1 will be described.

  In FIG. 8, 201 is a frame of the image reading apparatus, 202 is a platen glass, 203 is a light source that illuminates the document, 204, 205, and 206 are folding mirrors that guide the light diffused in the document, and 207 is guided by a folding mirror. It is a lens that images the light that has been emitted. Reference numeral 208 denotes a CCD that photoelectrically converts the imaged light. Reference numeral 209 denotes an electrical board that supplies electric power to the CCD and the light source and processes electrical signals from the CCD. The light source 203 and the electrical board 209 are electrically connected by a flat flexible cable (FFC) 210. The light source 203 and the folding mirror 204 are mounted on the first scanning body 211, and the folding mirrors 205 and 206 are mounted on the second scanning body 212. Reference numeral 213 denotes a contact prevention member provided in an area outside the document placement area on the lower surface of the document table glass in order to prevent the FFC 210 from contacting the document table glass 202.

  The first scanning body 211 and the second scanning body 212 are driven at a speed ratio of 2: 1 by rotating the motor and winding the wire in the same manner as shown in the first embodiment. The original can be scanned while keeping the optical path length between the original and the CCD constant.

  The FFC 210 is arranged so that a part thereof passes under the contact prevention member 213. The FFC 210 and the contact prevention member 213 in the present embodiment can also use the same configuration and arrangement as described in the first embodiment.

  When the first scanning body 211 moves in the sub-scanning direction (left-right direction in the figure) in accordance with the scanning operation, the curved state of the FFC 210 changes in the same manner as described in the first embodiment, and the original platen glass is changed. Curve in the direction of contact. However, since the contact preventing member 213 is provided, it does not directly contact the document table glass.

  In the above two embodiments, an example of FFC has been described as a cable. However, the present invention can obtain the same effect as long as the cable causes the same deformation as the FFC during the reading operation.

  Although the present invention has been described with reference to the above-described embodiments, the present invention is not limited to the configurations of the above-described embodiments.

It is sectional drawing of 1st Example of this invention. It is a figure showing the movement of the carriage in 1st Example of this invention. It is a figure showing the movement of the carriage in 1st Example of this invention. It is a figure showing the movement of the carriage in 1st Example of this invention. It is the figure seen from the upper direction in 1st Example of this invention. It is the figure seen from the side in the 1st example of the present invention. It is a figure showing the drive mechanism of the carriage in 1st Example of this invention. It is sectional drawing of 2nd Example of this invention.

Explanation of symbols

1 Frame 2 Document base 3 Carriage (unit)
5, 6 Light source 7, 8, 9 Mirror 10 Lens 11 CCD (Photoelectric conversion element)
12 Electrical board 13 Flat cable 14 Contact prevention member

Claims (5)

An original platen on which an original is placed in the original placement area;
A unit that moves in a moving direction along the document table when reading an image of the document;
A cable for electrically connecting the unit and the electrical board;
In an image reading apparatus having
The cable is disposed so as to straddle the document placement region and a region outside the document placement region in a direction perpendicular to the moving direction and along the document table.
An image reading apparatus comprising a contact prevention member for preventing the cable and the document table from contacting each other in an area outside the document placement area.   The contact prevention member is provided so as to come into contact with a region closer to the document placement region than a center of a width in a direction perpendicular to the moving direction of the cable and along the document table. The image reading apparatus according to claim 1.   The image reading apparatus according to claim 1, wherein the contact prevention member includes an elastic member and a low friction member, and the low friction member is provided in a region in contact with the cable. The unit includes a light source that illuminates the document,
The image reading apparatus according to claim 1, wherein the electrical board supplies power to the light source. The unit has a photoelectric conversion element for reading an image by receiving reflected light from the document,
The image reading apparatus according to claim 1, wherein the electrical board receives a signal from the photoelectric conversion element.

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