JP2000261616A - Image reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the vibration of a carriage with a relatively simple constitution, and to constitute this device compact by drawing wires from the lower part of a driven pulley for moving a traveling object, and then leading the wires toward the upper part of a guiding pulley. SOLUTION: A wire 17 goes half round a driven pulley 16, and then goes half round a guide pulley 15, and goes through pulleys 13 and 14, and goes half round the driven pulley 16 again. In this case, the guide pulley 15 is arranged at the lower part of the driven pulley 16 arranged at a second carriage. The wire 17 from the driven pulley 16 is guided downward by the guide pulley 15 arranged at the lower part of the driven pulley 16 so that the driven pulley 16 can be pressurized, and the second carriage can be prevented from coming to the surface. Thus, generation of any up and down or backward and forward shaking motion are eliminated. Also, the wire 17 goes half round the driven pulley 16 and the guide pulley 15, so that the deterioration of a transmitting force can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image reading apparatus, and more particularly to an image reading apparatus in which vibration of an optical system is prevented.

[0002]

2. Description of the Related Art An image reading apparatus used in a digital copying machine, an image scanner, or the like is a solid-state image sensor such as a CCD in which light reflected from a document is reduced and light-receiving elements of the same pixel size are arranged on one chip. An image of a document is formed on a light receiving surface on an image sensor, and information of the document is encoded and read.

FIG. 1 shows an example of the configuration of an image reading apparatus which is widely used in digital copiers and the like today. FIG.
In the figures, 1 is a document table, 2 is a document, 3 is a light source means, 4 is a first mirror, 5 is a second mirror, 6 is a third mirror, 7 is an imaging lens, and 8 is a CCD solid-state image sensor. Further, a first carriage (first traveling body) 11 in which the light source means 3 and the first mirror 4 travel integrally is formed, and a second carriage (first traveling body) in which the second mirror 5 and the third mirror 6 travel integrally. (Two traveling bodies) 12 are formed.

In an image reading apparatus for reading image information of a document by moving the first carriage 11 including such a light source and a mirror in the sub-scanning direction, the carriage 11, 1
In many cases, a wire is used as a driving force transmitting body, and a wire pulley is arranged to position and move the wire. This is because such a configuration is relatively easy to handle.

FIG. 4 is a perspective view showing the structure of a conventional image reading apparatus, and FIG. 5 is a wire arrangement diagram of a drive system of the image reading apparatus. 4 and 5, 11 is a first carriage, 12 is a second carriage, 13 to 16 are pulleys, 15 is a guide pulley, and 16 is a driven pulley. 17 is a wire.

In this example, after the wire 17 makes a half turn around the driven pulley 16, the guide pulley 15, the pulley 14,
After the pulley 13, it is stretched again so as to make a half turn around the driven pulley 16. As in this example, wire 17
When the driven pulley 16 and the guide pulley 15 are arranged in a horizontal direction, the carriage 11,
12, in particular, since there is no force for regulating the second carriage 12 in the vertical direction, the carriage 1 is not affected by external impact or vibration.
1 and 12 cause a vertical movement and a back and forth swing motion, and the vibrations of the carriages 11 and 12 give vibrations to the optical systems such as the mirrors 4, 5, and 6, which affect the reading of the image. This causes poor color separation, and monochrome causes jitter and the like. It is necessary to prevent such vibrations from occurring.

Further, the driven pulley 16 and the guide pulley 1
When 5 and 5 are arranged in the horizontal direction, an additional machine width is required in addition to the space in which the carriages 11 and 12 move. Therefore, it is necessary to arrange the wire 17 and the pulleys 13 to 16 so that the machine width is not increased and the installation area of the machine is reduced.

[0008]

As described above, the conventional image reading apparatus does not have a force for regulating the carriage in the vertical direction, so that there is a problem that vibration is easily generated by external impact or vibration. In addition, there is also a problem that the machine width is so large that it cannot be made compact. It is an object of the present invention to solve this problem and to realize an image reading apparatus which can prevent the carriage from vibrating with a relatively simple configuration and can be configured to be small in size.

[0009]

In order to achieve the above object, the present invention provides a light source means for irradiating a document, a plurality of mirror means for transmitting reflected light from the document illuminated by the light source means, A traveling body on which the light source means and the mirror means are mounted and moved; and a driving force transmission means for transmitting a driving force to the traveling body to scan the traveling body in the sub-scanning direction. In the image reading apparatus that reads an original by scanning, the driving force transmitting unit includes a wire and a plurality of pulleys, and the wire is pulled out from a lower part of a driven pulley that moves the traveling body among the plurality of pulleys. Thereafter, the wire is routed toward the upper part of the guide pulley for guiding the wire.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an image reading apparatus according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a block diagram of an image reading apparatus according to the present invention. As shown in the figure, the basic configuration is the same as the conventional one. In FIG. 1, 1 is a platen, 2
Is a document, 3 is a light source means, 4 is a first mirror, 5 is a second mirror, 6 is a third mirror, 7 is an imaging lens, and 8 is a CCD solid-state imaging device. Further, a first carriage (first traveling body) 11 in which the light source means 3 and the first mirror 4 travel integrally is formed, and a second carriage (first traveling body) in which the second mirror 5 and the third mirror 6 travel integrally. (Two traveling bodies) 12 are formed.

Document 2 placed on document table 1 in FIG.
Is illuminated by the light source means 3 and the reflected light is scanned in the sub-scanning direction at half the speed of the first carriage 11 through the first mirror 4 which is a turning mirror of the first carriage 11 for scanning in the sub-scanning direction. Then, an image is formed on the CCD solid-state imaging device 8 by the imaging lens 7 via the second mirror 5 and the third mirror 6 which are folding mirrors of the second carriage 12 to read document information.

According to the present invention, in an image reading apparatus in which both optical systems of the first carriage 11 and the second carriage 12 move as shown in FIG. 1, the position of the pulley and the method of tensioning the wire are devised to improve the second carriage. The guide pulley 15 is arranged below the driven pulley 16 disposed on the driven pulley 12, and the driven pulley 16 and the guide pulley 1
The length of the wire between 5 is shortened so that no wave is generated, and the size of the machine is reduced.

FIG. 2 is a perspective view showing the configuration of an embodiment of the present invention.
FIG. 3 shows a wire arrangement diagram. 2 and 3, reference numeral 11 denotes a first carriage, 12 denotes a second carriage, 1
3 to 16 are pulleys, and 17 is a wire. Of the pulleys 13 to 16, 15 is a guide pulley and 16 is a driven pulley. In this embodiment, after the wire 17 makes a half turn around the driven pulley 16, makes a half turn around the guide pulley 15, passes through the pulley 13 and the pulley 14, and is stretched again so as to make a half turn around the driven pulley 16.

As can be seen from FIGS. 2 and 3, in this embodiment, a guide pulley 15 is disposed below a driven pulley 16 disposed on the second carriage 12. As a result, the wire 17 from the driven pulley 16 is guided downward by the guide pulley 15 located below, so that the driven pulley 16 is pressed and the second carriage 12 does not float. Second carriage 1
If there is no lifting of 2, the occurrence of up-and-down movement and swinging movement back and forth is reduced. Therefore, the second carriage 12 is less likely to be affected by external shock or vibration.

The wire 17 is connected to the driven pulley 16,
Both are wound around the guide pulley 15 around a half of the pulley. This can prevent the transmission force (which is proportional to the contact area between the wire 17 and the pulleys 15 and 16) from decreasing.

Further, as shown in FIG. 3, the guide pulley 15 can be arranged so as not to be out of the moving range of the second carriage 12 at the end of the scanning in the sub-scanning direction. That is, at the end point of the carriage movement, the driven pulley 1
If the center of the guide pulley 15 and the center of the guide pulley 15 are arranged vertically, the necessary movement range for moving the carriage 12 ends here. In the conventional arrangement shown in FIG. 5, the guide pulley 15 is arranged outside the second carriage 12, that is, outside the range of movement of the second carriage 12. On the other hand, in the present embodiment, the width of the machine in the sub-scanning direction can be reduced, and the device can be downsized.

[0018]

As described above, according to the first aspect of the present invention, there are provided light source means for irradiating a document, a plurality of mirror means for transmitting reflected light from the document illuminated by the light source means, and a light source. First and second carriages on which the carriage and the mirror are mounted, and driving force transmitting means for transmitting a driving force to the carriage and causing the carriage to scan in the sub-scanning direction. In an image reading apparatus that reads an original by using a driving force transmission unit, the driving force transmission unit includes a wire and a plurality of pulleys. The wire is pulled out from a lower portion of a driven pulley that moves a second carriage among the plurality of pulleys, and then the wire Is guided so as to be directed toward the upper part of the guide pulley that guides the vehicle. As a result, the guide pulley is disposed below the driven pulley that moves the second carriage, and a force that presses the second carriage downward by the wire is generated. And an image reading apparatus that is less susceptible to external shocks and vibrations can be realized.

According to a second aspect of the present invention, at the end of scanning in the sub-scanning direction, the center of the driven pulley and the center of the guide pulley are positioned so as to be vertically arranged vertically. And Thus, by disposing the guide pulley below the driven pulley for moving the second carriage, the machine width can be minimized, the unnecessary area of the apparatus is reduced, and the apparatus is downsized. Can be realized.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an image reading apparatus in which the present invention is implemented.

FIG. 2 is a configuration perspective view of one embodiment of the present invention.

FIG. 3 is a wire arrangement diagram of the embodiment of the present invention shown in FIG. 2;

FIG. 4 is a perspective view showing a configuration of a conventional image reading apparatus.

FIG. 5 is a wire arrangement diagram of a drive system of the conventional image reading apparatus shown in FIG.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 document table 2 document 3 light source means 4 first mirror 5 second mirror 6 third mirror 7 imaging lens 8 CCD solid-state imaging device 11 first carriage 12 second carriage 13, 14 pulley 15 guide pulley 16 driven pulley 17 wire

Claims (2)

[Claims] 1. A light source means for irradiating a document, a plurality of mirror means for transmitting reflected light from the document illuminated by the light source means, and a traveling body on which the light source means and the mirror means are mounted and moved. And a driving force transmitting means for transmitting a driving force to the traveling body to scan the traveling body in a sub-scanning direction, wherein the driving force transmitting means reads a document by scanning the traveling body. Is composed of a wire and a plurality of pulleys, and the wire is pulled out from a lower portion of a driven pulley that moves the traveling body among the plurality of pulleys, and then pulled toward an upper portion of a guide pulley that guides the wire. An image reading device characterized by being rotated. 2. The apparatus according to claim 1, wherein at the end of scanning in the sub-scanning direction, the center of the driven pulley and the center of the guide pulley are vertically arranged vertically. The image reading device according to claim 1.