JP4302620B2 - Image reading device - Google Patents

Description

  The present invention includes a first moving carriage having a light source for irradiating image information reading light to a document placed on a document placing table and / or a mirror that reflects the image information reading light toward an optical sensor. The present invention relates to an image reading apparatus having a guide rail member for guiding a two-moving carriage in the sub-scanning direction.

In an image reading device such as a scanner, light (image information reading light) is emitted from a light source to a document, and the image information reading light reflected from the document is detected by an optical sensor such as a CCD. The image information of the original is read. In order to read image information at an arbitrary position on the original, it is necessary to drive the light source in the sub-scanning direction orthogonal to the scanning direction (main scanning direction) of the image information reading light. Further, the light guide mirrors for guiding the image information reading light emitted from the light source and reflected from the original to an imaging lens for forming an image on the CCD also needs to be driven in the sub-scanning direction. .
Usually, three light guide mirrors are used to guide the image information reading light to the imaging lens. One of the three light guide mirrors is incorporated in the same housing as the light source and is unitized as a first moving carriage. The remaining two light guide mirrors are also unitized as a second moving carriage different from the first moving carriage.

1 and 2 are configuration diagrams of the first moving carriage, the second moving carriage, and an image reading apparatus having a configuration for driving them in the sub-scanning direction. Hereinafter, the driving method of the first moving carriage and the second moving carriage in the conventional example will be described with reference to FIGS.
As shown in FIG. 1, the image reading apparatus B in the conventional example includes a first moving carriage 1, a second moving carriage 2, an imaging lens 3, a CCD 4, a guide rail 11, a wire 14, a wire-drum 16, and a belt 18. Etc., and is schematically configured.
The first moving carriage 1 is a unit obtained by incorporating a light source 6, a light guide mirror 7 and the like into a first moving frame 5 which is a predetermined frame. The second moving carriage 2 is a unit obtained by incorporating a light guide mirror 9 and a light guide mirror 10 into a second moving frame 8 which is also a predetermined frame.
The image information reading light emitted from the light source 6 is reflected by a document placed on a document placing table (not shown) and guided to the light guide mirror 7. Further, the image information reading light reflected by the light guide mirror 7 is further reflected by the light guide mirror 9 and the light guide mirror 10 in the second moving carriage 2 and reflected toward the imaging lens 3. Is done. As a result, an image of the original is formed on the CCD 4, and information on the image is read by the CCD 4.

By the way, the first moving carriage 1 and the second moving carriage 2 are supported by the guide rail 11 while the image information reading light is applied to the original, and the image information reading light is scanned in the sub-scanning direction (FIG. 1 and the direction of the arrow x shown in FIG. 2). Hereinafter, a structure for sliding the first moving carriage 1 and the second moving carriage 2 in the sub-scanning direction will be described.
As shown in FIG. 2, a wire 14 is stretched between the first fixed point 12 and the second fixed point 13. A part of the first moving frame 5 in the first moving carriage 1 is coupled to a specific portion of the wire 14. The wire 14 is wound around a pulley 15 formed on the second moving frame 8 in the second moving carriage 2.
A part of the wire 14 is wound around a drum pulley 17 formed on the wire drum 16. The wire drum 16 is rotated via a belt 18 by driving a motor 19 as a driving source. As the wire drum 16 rotates, the portion of the wire 14 wound around the drum pulley 17 is changed, and the first moving carriage 1 and the second moving carriage 2 are supported by the guide rail 11 in the sub-scanning direction. While sliding. According to the above-described configuration, the sliding speed of the second moving carriage is maintained at half the sliding speed of the first moving carriage 1.

By the way, in recent years, an improvement in the reading speed of image information is an important issue in an image reading apparatus. For this purpose, it is desired to drive the first moving carriage 1 and the second moving carriage 2 as fast as possible. However, when the first moving carriage 1 and the second moving carriage 2 are slid at a high speed in the configuration as described above, the first moving carriage 1 and the second moving carriage 2 vibrate with the sliding. As a result, there is a problem that the irradiation accuracy of the image information reading light to the CCD 4 is deteriorated.
Here, Patent Document 1 and the like disclose a configuration for reducing vibration during driving of the first moving carriage 1. In the technique described in Patent Document 1, the wire 14 described above is attached to the first moving carriage 1 so as to press the first moving carriage 1 against the guide rail 11 by its tension. According to such a configuration, it is possible to reduce vibration during driving of the first movable carriage 1 by pressing against the guide rail 11.
JP 2000-184138 A

However, in the technique described in Patent Document 1 described above, in order to press the first moving carriage against the guide rail, it is necessary to bend the wire at the attachment position to the first moving carriage. The bending angle changes with respect to the sliding position of the first moving carriage. Accordingly, the tension by the wire changes with respect to the sliding of the first moving carriage, the force pressed against the guide rail changes, and consequently the sliding speed of the first moving carriage changes. Therefore, there is a problem in that the scanning speed of the image information reading light in the sub-scanning direction changes, and image information distorted in the sub-scanning direction is read by the CCD.
Further, when the first moving carriage is slid on the central portion of the guide rail, the force for pressing the first moving carriage against the guide rail is weakened. There is also a problem that vibration of the moving carriage cannot be suppressed.
Accordingly, the present invention has been made in view of the above circumstances, and an object of the present invention is to obtain stable sliding of the first moving carriage and / or the second moving carriage in the sub-scanning direction. An object of the present invention is to provide an image reading apparatus capable of maintaining high irradiation accuracy of image information reading light on a CCD (optical sensor) even when the sliding speed thereof is increased.

In order to achieve the above object, the present invention comprises at least a light source and a first mirror that reflects light emitted from the light source and reflected on the document, and is slid in the sub-scanning direction by the first guide rail member. A first moving carriage to be guided; and a second mirror that reflects at least light reflected by the first mirror toward the optical sensor, and is slidably guided in the sub-scanning direction by a second guide rail member. The first moving carriage is supported upward and downward by the first guide rail member, and the second moving carriage is upward and downward by the second guide rail member. in the image reading apparatus comprising supported downwardly, and the member for supporting upward the first moving carriage of the first guide rail member, said second guide rail section And a member for supporting the first moving carriage downward of the first guide rail member. The member for supporting the first moving carriage downward of the first guide rail member is the first guide rail member. The image reading apparatus is configured separately from a member that supports the first moving carriage upward.
A member for supporting the first moving carriage of the first guide rail member upward and a member for supporting the second moving carriage of the second guide rail member downward are integrally configured. The guide rail member can be formed with a small cross-sectional dimension and sufficient strength.
In addition, it is desirable that an upper contact portion of the first moving carriage and / or the second moving carriage with the first guide rail and / or the second guide rail is an elastic member. In this case, the restoring force of the elastic member makes it possible to maintain high accuracy in the vertical position of the first moving carriage and / or the second moving carriage, and also improves the vibration absorption.

  According to the present invention, each of the first moving carriage and the second moving carriage is stably slid by the guide rail for each, and even when the sliding speed is increased, the irradiation accuracy of the image information reading light to the CCD is improved. It can be kept high.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings so that the present invention can be understood. The following embodiment is an example embodying the present invention, and does not limit the technical scope of the present invention.
FIG. 1 is a side view of the image reading apparatus according to the first embodiment of the present invention. FIG. 2 is a side view of the first moving carriage and the second moving carriage in the image reading apparatus according to the first embodiment of the present invention. FIG. 3 is a side view showing a structure for sliding, FIG. 3 is a cross-sectional view showing a support structure for the first moving carriage and the second moving carriage in the image reading apparatus according to the first embodiment of the present invention, and FIG. FIG. 5 is a sectional view showing a support structure of a first moving carriage in an image reading apparatus according to a second embodiment of the invention. FIG. 5 shows a support structure of the first moving carriage in the image reading apparatus according to the third embodiment of the invention. It is sectional drawing shown. In addition, about the structure similar to a prior art example, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

(1) Features of the image forming apparatus according to the embodiment of the present invention.
1 and 2 show an image forming apparatus A according to the first embodiment of the present invention. The difference between the image reading apparatus A according to the first embodiment of the present invention and the image reading apparatus B in the conventional example is as follows. That is, the image forming apparatus A includes a light source 6 and a light guide mirror 7 (first mirror) that reflects light emitted by the light source 6 and reflected by an unillustrated document, and is in the sub-scanning direction (FIG. 1, FIG. 1). The first moving carriage 1 ′ slid in the direction of the arrow x shown in FIG. 2, the light guide mirror 8 for reflecting the light reflected by the light guide mirror 7 toward the CCD 4 (optical sensor), and the light guide And a second moving carriage 2 ′ which includes an optical mirror 9 (second mirror) and is slid in the sub-scanning direction. This is the same as the image reading apparatus B in the conventional example. However, the first moving carriage 1 ′ and the second moving carriage 2 ′, and the support structure of each of the carriages supported by the housing on the image reading apparatus A main body side, are different from the image reading apparatus B in the conventional example. . The configuration for sliding the first moving carriage 1 ′ and the second moving carriage 2 ′ in the sub-scanning direction (the wire 14, the motor 19 and the like) is the same as that of the conventional example, and thus the description thereof is omitted. To do.

(2) Support structure in the image reading apparatus of the first first carriage and the second carriage.
FIG. 3 is a cross-sectional view showing a support structure of the first moving carriage 1 ′ and the second moving carriage 2 ′ in the image reading apparatus A according to the first embodiment of the present invention. As shown in FIG. 3, the first moving frame 5 ′, which is the housing frame of the first moving carriage 1 ′, has an upper first contact portion 20 and a lower first contact portion 21 integrally. Similarly, the second moving frame 8 ′, which is the housing frame of the first moving carriage 2 ′, integrally includes an upper second contact portion 22 and a lower second contact portion 23. The image reading apparatus A includes a guide member 24 (a part of the first guide rail and the second guide rail) having a U-shaped cross section along the sub-scanning direction, and the sub-scanning similarly. An outer frame 30 integrally provided with an upper surface member 25 extending horizontally along the direction is provided.
The upper first contact portion 20 is slidably contacted with an upper surface member 25 which is a part of the outer frame 30 in the image reading apparatus A, and the lower first contact portion 21 is configured to be the guide member. The first moving frame 5 ′ of the first moving carriage 1 ′ is guided in the sub-scanning direction by being slidably contacted with the upper surface of 24. That is, the first moving carriage 1 ′ is sandwiched by the upper surface member 25 and the guide member 24 from both the upper and lower directions, and is guided in the sub-scanning direction while maintaining the state during an image reading operation or the like. The upper surface member 25 and the guide member 24 are an example of a first guide rail member.

The upper second contact portion 22 in the second movable carriage 2 ′ is slidably in contact with the back surface of the lower first contact portion 21 of the guide member 24, and Similarly, the lower second contact portion 23 is slidably in contact with the back surface of the guide member 24 on which the upper second contact portion 22 contacts. That is, the second moving carriage 2 'is sandwiched from above and below by the guide member 24 having a substantially U-shaped cross section, and is guided in the sub-scanning direction in this state. The guide member 24 is an example of a second guide rail member. Further, as described above, the guide member 24 also serves as a first guide rail member and a second guide rail member. In this case, the second guide rail member serves as the first guide rail member. It also serves as a part of the rail member.
Here, it is conceivable that the upper first contact portion 20 is supported by a mounting plate 26a rich in elasticity. Thus, the upper first contact portion 20 is urged toward the upper surface member 25 (an example of the first guide rail) by the elastic force of the mounting plate 26a. Similarly, the second movement abutting on the guide member 24 (an example of a second guide rail member) is made by configuring the mounting plate 26a having the upper second abutting portion 22 with an elastic member. The carriage 2 ′ is also elastically supported.
With the above configuration, the first moving carriage 1 ′ and the second moving carriage 2 ′ are elastically supported by the mounting plates 26a and 26b on the first moving carriage 1 ′ and the second moving carriage 2 ′. Since the vibration of the moving carriage 2 ′ is absorbed, each position can be kept with extremely high accuracy.
The lower first contact portion 21 and the lower second contact portion 23 are supported by an elastic mounting plate, or the upper first contact portion 20 and the lower first contact portion. 21, a configuration in which all of the upper second contact portion 22 and the lower second contact portion 23 are supported by a mounting plate is also conceivable, and the above-described effects can also be obtained by these configurations.

(3) Regarding the second embodiment.
In the first embodiment described above, an example has been disclosed in which both the first moving carriage and the second moving carriage are sandwiched between the guide rail members from above and below and are thereby guided in the sub-scanning direction. The invention is not limited to this. That is, it may be configured such that either the first moving carriage or the second moving carriage is sandwiched between the guide rail members from above and below as required.
FIG. 4 is a cross-sectional view showing a structure in which only the first movable carriage side is sandwiched between upper and lower guide rails and elastically indicated in the image reading apparatus according to the second embodiment of the present invention.
As shown in FIG. 4, the image reading apparatus A ′ according to the second embodiment of the present invention has a guide member 24 ′ having a U-shaped cross section, and is attached with its open portion facing downward. It is. Further, the upper surface member in which the upper first contact portion 20 in the first moving carriage 5 ′ having the light source 6 and the light guide mirror 7 (see FIGS. 1 and 2) is a part of the outer frame in the image reading apparatus A ′. The lower surface side first contact portion 21 is slidably contacted with the upper surface of the guide member 24 '. That is, the first moving carriage 1 ′ is sandwiched by the upper surface member 25 and the guide member 24 ′ from both the upper and lower directions, and is guided in the sub-scanning direction while maintaining the state during an image reading operation or the like.
On the other hand, in the second movable carriage 2 ″ including the light guide mirror 8 and the light guide mirror 9 (see FIGS. 1 and 2), only the contact portion 23 directed downward is supported by the guide member 24 ′. In the image reading operation or the like, the guide member 24 'guides only in the sub-scanning direction.
The second moving carriage 2 ″ has a lower sliding speed (half speed) than the first moving carriage 1 ′, and vibration due to sliding may not be a problem. In this case, as described above, only the first moving carriage 1 ′ may be sandwiched from above and below, and of course, only the second moving carriage can be sandwiched from above and below.

(4) Regarding the third embodiment.
In the first and second embodiments described above, the upper contact portion of the first moving carriage is contacted by the upper surface member that is a part of the outer frame of the image reading apparatus, and the lower contact portion is Although the example which contact | abuts by a part of guide member which opposes an upper surface member (refer FIG. 3, FIG. 4) was disclosed, this invention is not limited to this. That is, as shown in FIG. 5, the guide member 24 ″ having a U-shaped cross section has a wide vertical width, and the upper first contact portion 20 of the first moving carriage 1 ′ is formed. The lower first contact portion 21 may be brought into contact with each inner surface of the guide member 24 ″.
In addition, various modifications are conceivable within the scope of the present invention.

1 is a side view of an image reading apparatus according to an embodiment of the present invention. FIG. 5 is a diagram showing a configuration for sliding the first moving carriage and the second moving carriage in the image reading apparatus according to the embodiment of the present invention. FIG. 3 is a cross-sectional view showing a support structure for a first moving carriage and a second moving carriage in the image reading apparatus according to the first embodiment of the present invention. Sectional drawing which shows the support structure of the 1st movement carriage in the image reading apparatus which concerns on 2nd embodiment of this invention. Sectional drawing which shows the support structure of the 1st movement carriage in the image reading apparatus which concerns on 3rd embodiment of this invention.

Explanation of symbols

A ... Image reading apparatus A 'according to the first embodiment of the present invention ... Image reading apparatus A "according to the second embodiment of the present invention ... Image reading apparatus B according to the third embodiment of the present invention ... Conventional Image Reading Device 1 in Example ... First Moving Carriage 1 'of Image Reading Device in Conventional Example ... First Moving Carriage 2 in Image Reading Device According to First, Second and Third Embodiments of Present Invention ... Conventional Second moving carriage 2 ′ included in the image reading apparatus in the example. Second moving carriage 2 ″ included in the image reading apparatus according to the first embodiment of the present invention. In the image reading apparatus according to the second embodiment of the present invention. Second moving carriage 3 ... Imaging lens 4 ... CCD (optical sensor)
5 ... 1st moving frame 6 ... Light source 7, 9, 10 ... Light guide mirror 8 ... 2nd moving frame 11 ... Guide rail 12 ... 1st fixed point 13 ... 2nd fixed point 14 ... Wire 15 ... Pulley 16 ... Wire drum 17 ... Drum pulley 18 ... Belt 19 ... Motor

Claims (4)

A first moving carriage that includes at least a light source and a first mirror that reflects the light emitted from the light source and reflected by the document, and is slidably guided in the sub-scanning direction by the first guide rail member;
A second moving carriage that includes at least a second mirror that reflects the light reflected by the first mirror toward the optical sensor and is slidably guided in the sub-scanning direction by a second guide rail member; and,
In the image reading apparatus, the first moving carriage is supported upward and downward by the first guide rail member, and the second moving carriage is supported upward and downward by the second guide rail member .
A member for supporting the first moving carriage of the first guide rail member upward and a member for supporting the second moving carriage of the second guide rail member downward are configured integrally.
The member of the first guide rail member that supports the first moving carriage downward is configured separately from the member of the first guide rail member that supports the first moving carriage upward. An image reading apparatus. A member for supporting upward the first mobile calibration Li Tsu di in the first guide rail member, and the member for supporting downwards the member supporting upward the second mobile carriage in the second guide rail member The image reading apparatus according to claim 1, wherein the image reading apparatus is configured by a rail having a substantially U-shaped cross section.   3. The image reading apparatus according to claim 1, wherein an upper contact portion of the first moving carriage that is contacted by the first guide rail member is made of an elastic member.   The image reading apparatus according to claim 1, wherein an upper contact portion of the second movable carriage that is contacted by the second guide rail member is made of an elastic member.

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