JP3567738B2 - Image reading device - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading apparatus used for a PPC, a facsimile, and the like, and more particularly to a method for setting a gap between a contact glass and a white pressure plate to an appropriate value in accordance with a thickness of a document to reduce skew and flutter of the document. The present invention relates to a prevented image reading apparatus.
[0002]
[Prior art]
A contact glass provided at the reading section in the middle of the conveyance path for a CCD, a reduction optical system, and a sheet-like document, and a white pressure plate (also referred to as a white reference plate) provided opposite to the contact glass and opposite to the conveyance path In an image reading apparatus having a reading system composed of (1) and (2), the fluttering of the paper during paper passing appears as vertical line distortion of the image. Therefore, in the prior art, for example, as shown in FIG. 11, the white pressure plate 6 is pressed against the contact glass 10 by the spring 7 and the spacer 11 is interposed between the white pressure plate 6 and the gap is strictly controlled.
[0003]
In FIG. 11, reference numerals 1 and 2 denote a first roller and a first roller for feeding the original 13 to the reading unit, reference numerals 3 and 4 denote a second roller and a second roller, 5 a square pipe for reinforcing the white pressure plate 6, Denotes a spring for pressing the white pressure plate 6 against the contact glass 10, and 8 and 9 denote an upper housing and a lower housing of the image reading apparatus. In the following description, the arrangement of the spacers relating to the white pressure plate 6 and the contact glass 10 will be described, and the description of the configuration of the peripheral portion will be omitted.
As this type of image reading apparatus, an apparatus disclosed in Japanese Patent Application Laid-Open No. 9-270884 can be cited.
[0004]
[Problems to be solved by the invention]
In the above prior art, the gap value is usually set to a relatively small value in order to suppress fluttering of the document. The load is rubbed, resulting in skew, image expansion, and the like.
SUMMARY OF THE INVENTION An object of the present invention is to solve the above-described problems in the prior art, and to set the gap between the contact glass and the white pressure plate to an appropriate value in accordance with the thickness of the document, thereby making the document skew or fluttering. It is an object of the present invention to provide an image reading apparatus in which the problem is prevented.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, an image reading apparatus according to the present invention is characterized in that a gap value can be set in a plurality of levels.
More specifically, in the image reading apparatus according to the present invention, a contact glass 10 provided in a reading unit in the middle of a sheet-like document conveying path is provided. In the image reading apparatus having the white pressure plate 6 provided in the above, spacers for regulating the gap between the contact glass 10 and the white pressure plate 6 are provided on the opposing surfaces (11, 14) of the contact glass 10 and the white pressure plate 10, respectively. In addition, the contact glass 10 can be arranged in the front-rear direction of the document conveying direction.
[0006]
Further, in the image reading apparatus according to the present invention, spacers for regulating the gap between the contact glass 10 and the white pressure plate 6 are provided on both front and back surfaces (11 and 16) of the contact glass 10, and the contact glass 10 It is characterized in that it can be placed upside down along the direction of document transport.
Further, in the image reading apparatus according to the present invention, spacers for regulating the gap between the contact glass 10 and the white pressure plate 6 are provided on both sides of the contact glass 10 and the surface of the white pressure plate facing the contact glass (11 and 16, respectively). 14), and the contact glass can be arranged upside down and upside down along the transport direction of the document.
[0007]
In the image reading apparatus according to the present invention, by adopting the above-described configuration, it is possible to set a gap value between the contact glass 10 and the white pressure plate 6 in a plurality of steps. That is, in the image reading apparatus according to the present invention, the gap between the contact glass 10 and the white pressure plate 6 can be set to an appropriate value corresponding to the thickness of the document, and the skew and fluttering of the document can be prevented. .
Further, the setting change of the gap value between the contact glass 10 and the white pressure plate 6 can be easily performed by changing the arrangement (set) of the contact glass 10.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail based on preferred embodiments shown in the drawings.
1 to 3 show a first embodiment of the present invention. The image reading apparatus according to the present embodiment has a configuration in which the gap target value can be changed in two stages when a normal document and a thick document are passed.
FIG. 1 shows the positions where the spacers 11 and 11 are attached on the contact glass 10 in this embodiment. The contact glass 10 is fixed to the lower housing 9 of the image reading device by a clip 15. The two spacers 11 are stuck outside of the reading area at positions where the clips 15 do not touch.
[0009]
Further, a spacer 14 is attached on the white pressure plate 6 so as to face the contact glass 10. In this example, the spacer 14 is for setting a gap value for a normal document, and the gap value for a thick document is configured to be set by the total value of the spacer 14 and the spacer 11.
FIG. 2 is a diagram illustrating a configuration in a gap value setting state for a normal document. Here, the spacer 14 on the white pressure plate 6 pressed by the spring 7 comes into contact with the contact glass 10, and the thickness of the spacer 14 is a gap value.
[0010]
FIG. 3 is a diagram showing a configuration in which a gap value is set for a thick document. As can be understood from comparison with FIG. 2, the arrangement of the contact glass 10 is reversed (right and left in the figure). In this case, the spacer 14 on the white pressure plate 6 pressed by the spring 7 abuts on the spacer 11 on the contact glass 10, and the total thickness of the spacers 11 and 14 is a gap value, that is, a gap for a thick document. Value.
With this configuration, in this embodiment, two types of gap values can be set.
[0011]
4 to 6 show a second embodiment of the present invention. The image reading apparatus according to the present embodiment also has a configuration in which the target gap value can be changed in two stages when a normal document and a thick document are passed. In the present embodiment, unlike the first embodiment, two types of gap values can be set by disposing the contact glass 10 upside down.
FIG. 4 is a diagram showing the positions where the spacers 11 (front surface) and 16 (back surface) are attached on the contact glass 10 in this embodiment. The contact glass 10 is fixed to the lower housing 9 of the image reading device by a clip 15.
Note that the spacers 11 and 16 are both attached to the front and back of the contact glass 10 at locations where the clips 15 do not hit outside the reading area.
[0012]
FIG. 5 is a diagram showing a configuration in which a gap value is set for a normal document. The white pressure plate 6 pressed by the spring 7 contacts the spacer 11 on the contact glass 10, and the thickness of the spacer 11 becomes the gap value. .
FIG. 6 is a diagram showing a configuration in which a gap value is set for a thick document, and the method of mounting the contact glass 10 is upside down.
In this case, the white pressure plate 6 pressed by the spring 7 hits the spacer 16 on the contact glass 10, and the thickness of the spacer 16 becomes the gap value. With such a configuration, in this embodiment, two types of gap values can be set.
[0013]
7 to 10 show a third embodiment of the present invention. The image reading apparatus according to the present embodiment has a configuration in which the target gap value can be changed in three stages between when a normal document and a thick document are passed. In the present embodiment, three types of gap values can be set by arranging the contact glass 10 in front and back and front and back.
In this embodiment, a spacer on the side of the white pressure plate 6 is further added to the configuration shown in the second embodiment, and the contact glass 10 is set upside down and back upside down. The gap value for the document can also be set.
[0014]
FIG. 7 is a diagram showing positions where the spacers 11 and 16 are attached on the contact glass 10 in this embodiment. The two spacers 11 (front surface) and 16 (back surface) are attached to a position outside the reading area where the clip 15 does not touch. The spacer 11 and the spacer 16 have different thicknesses.
FIG. 8 is a diagram showing a configuration in which a gap value for a normal document is set. The spacer 14 on the white pressure plate 6 pressed by the spring 7 directly contacts the contact glass 10, and the thickness of the spacer 14 corresponds to the gap value. Become.
[0015]
FIG. 9 is a diagram showing a configuration in which a gap value is set for a thick document. The arrangement of the contact glass 10 is reversed from the configuration shown in FIG. In this case, the spacer 14 on the white pressure plate 6 pressed by the spring 7 comes into contact with the spacer 11 on the contact glass 10, and the total thickness of the spacers 14 and 11 becomes the gap value.
FIG. 10 is a configuration diagram with a gap value setting for a very thick original, and the arrangement of the contact glass 10 is upside down from the configuration shown in FIG.
[0016]
In this case, the spacer 14 on the white pressure plate 6 pressed by the spring 7 comes into contact with the spacer 16 on the contact glass 10, and the total thickness of the spacers 14 and 16 becomes the gap value.
By adopting such a configuration, in the present embodiment, three types of gap values can be set.
It should be noted that each of the above embodiments is merely an example of the present invention, and it is needless to say that the present invention should not be limited to these.
[0017]
【The invention's effect】
As described above in detail, according to the present invention, it is possible to set the gap between the contact glass and the white pressure plate to an appropriate value in accordance with the thickness of the document, thereby preventing the skew and fluttering of the document. This has a remarkable effect that a reading device can be realized.
[Brief description of the drawings]
FIG. 1 is a view showing a position where a spacer 11 is attached on a contact glass 10 according to a first embodiment of the present invention.
FIG. 2 is a configuration diagram of the embodiment shown in FIG. 1 with a gap value set for a normal document.
FIG. 3 is a configuration diagram of the embodiment shown in FIG. 1 with a gap value setting for a thick original.
FIG. 4 is a view showing a position where spacers 11 and 16 are attached on a contact glass 10 according to a second embodiment of the present invention.
FIG. 5 is a configuration diagram of the embodiment shown in FIG. 5 when setting a gap value for a normal document;
6 is a configuration diagram of the embodiment shown in FIG. 5 with a gap value setting for a thick document.
FIG. 7 is a view showing a position where spacers 11 and 16 are attached on a contact glass 10 according to a third embodiment of the present invention.
8 is a configuration diagram of the embodiment shown in FIG. 7 with a gap value set for a normal document.
9 is a configuration diagram of the embodiment shown in FIG. 7 with a gap value setting for a thick document.
10 is a configuration diagram of the embodiment shown in FIG. 7 with a gap value setting for a very thick document.
FIG. 11 is a diagram showing a schematic configuration of a main part of a reading apparatus according to a conventional technique.
[Explanation of symbols]
5 Square pipe 6 White pressure plate 7 Spring 10 Contact glass 11, 16 Spacer on contact glass 14 Spacer on white pressure plate 15 Clip

Claims (3)

An image reading apparatus comprising: a contact glass provided in a reading unit in the middle of a sheet-like document conveyance path; and a white pressure plate provided opposite to the contact glass and opposite to the conveyance path. A spacer for restricting a gap between the contact glass and the white pressure plate is provided on each of opposing surfaces of the contact glass and the white pressure plate, and the contact glass can be disposed in a front-rear direction in a conveying direction of the document. Reader. An image reading apparatus comprising: a contact glass provided in a reading unit in the middle of a sheet-like document conveyance path; and a white pressure plate provided opposite to the contact glass and opposite to the conveyance path. An image reading device, wherein spacers for regulating a gap between the contact glass and the white pressure plate are provided on both front and back surfaces of the contact glass, and the contact glass can be arranged upside down along the document transport direction. An image reading apparatus comprising: a contact glass provided in a reading unit in the middle of a sheet-like document conveyance path; and a white pressure plate provided opposite to the contact glass and opposite to the conveyance path. Spacers for regulating the gap between the white pressure plate and the white pressure plate are provided on both sides of the contact glass and on the surface of the white pressure plate facing the contact glass, respectively, and the contact glass is arranged in front and back, front and back in the transport direction of the document. An image reading device, wherein the image reading device is enabled.

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