JP3466333B2 - Image reading device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading device.

[0002]

2. Description of the Related Art A digital copying machine (hereinafter referred to as a digital PPC) is capable of editing an image and is used as a multifunctional machine with a facsimile, a printer and the like.
Has been closed up. An image reading device of such a digital PPC (hereinafter referred to as a digital scanner, reference numeral 1
Indicate. ) Will be described.

In FIG. 5, reference numeral 2 is a contact glass on which an original is placed, and reference numeral 24 is a pressure plate for covering the contact glass 2. A first traveling body 5 is provided below the contact glass 2. The first traveling body 5 is integrally provided with a halogen lamp 3 for illuminating a document placed on the contact glass 2 and a first mirror 4 for changing the optical path L of the document reflected light.

Similarly to the first traveling body 5, below the contact glass 2, there are provided second mirrors M1 and M2 for further changing the optical path changed by the first mirror 4, and a scanning direction A indicated by an arrow A. A second traveling body 8 that moves to the right is provided.

The first traveling body 5 and the second traveling body 8 are
As shown in FIG. 6, it is slidably supported by a pair of two rails 13a and 13b that are long in the scanning direction A, and the speed of the second traveling body 8 is 1/2 that of the first traveling body 5. It is adapted to be moved in the scanning direction A by a known driving means by winding a wire or a belt to which the principle of a moving pulley is applied. The drive means includes a drive motor and a speed reduction mechanism.

The first for the pair of rails 13a, 13b
The supporting portions of the traveling body 5 and the second traveling body 8 are such that the sliding portions with respect to the rail have a certain degree of mutual contact so that the supporting portions of the traveling body 5 and the second traveling body 8 are moved while maintaining the mutual parallel of the first mirror 4 and the second mirrors M1, M2. It has a contact relationship. Also, a pair of rails 13a, 1
3b is configured to be held parallel to the contact glass 2, and both ends of the rail extending in the scanning direction A are fixed to the vertical planes of the side plates of the image reading apparatus, respectively. It is supported by a doubly supported beam.

An imaging lens 9 for converging the reflected light whose optical path is changed through each mirror of the first traveling body 5 and the second traveling body 8, that is, the first mirror 4, the second mirrors M1, M2, and this. An image forming unit 11, which integrally holds a light receiving element 10 formed of a CCD for receiving the reflected light collected by the image forming lens 9, is provided in a bridge shape between the pair of rails, and each end is fixed. ing. The light receiving element 10 converts the image information contained in the reflected light of the document into an electric signal. This converted signal is sent to the scanner substrate 1 separately from the image forming unit 11.
2 is transmitted.

Since the focal length of the image forming lens 9 varies and the image is blurred unless the light receiving surface of the light receiving element 10 is held in parallel with the image forming surface of the image forming lens 9, the position of the light receiving element 10 is one. It is necessary to finely adjust the image lens 9. Therefore, the position of the imaging lens 9 and the light receiving element 10 is adjusted, and these are held together as one unit.
Form 1 is preferred. Further, in order to obtain the positional accuracy of the image forming unit 11 with respect to the contact glass 2, it is appropriate to fix the image forming unit 11 between the rails 13a and 13b.

Here, as a method of attaching the image forming unit 11 to the pair of rails 13a and 13b, there is a configuration shown in FIG. 7 or 8 in which a portion indicated by reference numeral 20 in FIG. 6 is enlarged. In the configuration shown in FIG. 7, the end of the imaging unit 11 is directly fixed to the rail 13b with the screw 21. Further, in the configuration shown in FIG. 8, the end portion of the imaging unit 11 is fixed by the screw 21 via the pedestal 22.

[0010]

However, in the image reading apparatus according to the above-mentioned prior art, the vibration generated by the drive motor of the drive means for driving the first traveling body and the second traveling body and the deceleration mechanism thereof, and the external connection machine. , For example, the vibration generated in the printer unit or the like travels through the rail during the image reading to the first traveling body and the second traveling body.
It is transmitted to the traveling body, the imaging unit, and the like. In the type in which the image forming unit is provided between the rails, the rail is supported in the shape of a doubly supported beam, so that the image forming unit is, so to speak, floating in the air, so that it easily vibrates.
When vibrating, there is a problem that when a read image is reproduced, it appears as line fluctuations and uneven density.

Therefore, an object of the present invention is to provide an image reading apparatus capable of reducing the vibration of the image forming unit and improving the quality of a reproduced image.

[0012]

In order to achieve the above object, the present invention provides (1) a contact glass on which an original is placed, and a lamp which is provided below the contact glass and illuminates the original on the contact glass. And a first traveling body that moves in the scanning direction by including a first mirror that changes the optical path of the document reflected light, and a second mirror that further changes the optical path changed by the first mirror in the scanning direction. A second traveling body that moves at a speed half that of the first traveling body;
A pair of rails that guide the traveling of at least one of the traveling body and the second traveling body, and an imaging lens that collects the reflected light whose optical path is changed by each mirror of the first traveling body and the second traveling body. And in the image reading device in which the image forming unit that integrally holds the light receiving element that receives the collected reflected light and the image forming unit is fixed between the pair of rails, between the pair of rails , coupled with scan <br/> tape member which gave damping function, to have a damping function to the stay member
Therefore, a sandwich structure in which a viscoelastic polymer material is sandwiched between steel plates is used.
The constrained type vibration damping steel plate that is manufactured is used (Claim 1).

(2) In the image reading apparatus described in (1), the stay member is provided on a pair of rails, and the lengthwise direction of the rails.
In contrast to the direction, a bridge is formed by the combination of two intersecting members
It is provided (claim 2).

[0014]

[0015]

[0016]

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION In FIG. 1, rails 13a and 1 are provided.
3b guides the second traveling body 8 in the scanning direction A. Although not shown in this figure, the first traveling body 5 is also guided by the pair of rails.

In this example, these rails 13a, 13b
A stay member 15 is provided in a bridge shape at right angles to the longitudinal direction of the. The stay member 15 has its longitudinal ends fixed to the rails 13a and 13b by screws 23. In the following example, the set screws for fixing the stay member to the rails are all indicated by reference numeral 23.

As described above, by connecting with the stay member 15, the structural strength can be increased and the vibration received by the light receiving element 10 can be attenuated. In order to investigate the effect of providing the stay member, as shown in FIG. 1, when the stay member made of a groove-shaped zinc steel plate metal plate is coupled to the rail, and when the stay member is not provided, The vertical vibrations at 10 parts of the light receiving element were measured. The results are shown in Table 1.
Shown in.

[0020]

[Table 1]

As can be seen from Table 1, in the case where the stay member is provided, the vibration is reduced to a little more than 1/2 in RMS value as compared with the case where the stay member is not provided. It has been found that when an original is read and reproduced in each of these structural states, an abnormal image in which a diagonal line that is conventionally generated at 400% enlargement becomes jagged can be improved.

As the form of the stay member, as shown in FIG. 1, in addition to the example in which one stay member is arranged between the rails 13a and 13b at right angles to the longitudinal direction of the rail, as shown in FIG. , 2 places in the longitudinal direction of the rail, stay member 1
It is also possible to provide 5-1 and 15-2. Alternatively, as shown in FIG. 3, the two stay members 15-3 and 15-4 may be provided in a crossing combination at a position where the imaging unit 11 is arranged.

These stay members 15, 15-1, 15
-2, 15-3, and 15-4 are effective even if they are made of a zinc steel plate, but vibration can be further suppressed by providing a vibration damping function. There are a method of attaching a damping material to the stay member, which has a damping function, and a method of forming the stay member itself from a damping steel plate. As the vibration damping material to be attached to the stay member, the product names “Regetrex” and “Nitohard” manufactured by Nitto Denko Corporation and the product name “Hamadanpa” manufactured by Yokohama Rubber can be used.

As the vibration damping steel plate, as shown in FIG. 4, there is a constrained vibration damping steel plate having a structure in which a viscoelastic polymer material 17 is sandwiched between two steel plates 16 in a sandwich shape. As the restraint type vibration-damping steel plate, the product name "Bypress" manufactured by Nippon Steel Co., Ltd. or the product name "Dampley" manufactured by Kobe Steel can be used.

As a stay member having a structure as shown in FIG.
The case of using a zinc steel plate (thickness t = 1.2 mm) and FIG.
In the case where the constrained type vibration damping steel plate (thickness t = 1.2 mm) as shown in FIG. The results are shown in Table 2.

[0026]

[Table 2]

As can be seen from Table 2, the light receiving element 10
It can be seen that the vibration of can be further reduced. In addition to increasing the rigidity of the pair of rails that support the imaging unit 11 by providing the stay member, the viscoelastic polymer material absorbs the vibration energy from various vibration sources that have propagated to the rails. It is thought that it was converted to internal energy and absorbed.

Thus, by providing the stay member with a vibration damping function, the device can be efficiently and efficiently provided without complicating the device.
The vibration of the imaging unit 11 can be reduced, and the quality of the reproduced image by the image reading device can be improved.

When the first traveling body 5 and the second traveling body 8 are supported by a pair of different rails, respectively,
For each pair of rails, the stay member can be configured according to the example shown in FIG. 1, or the configuration described in FIGS. 2, 3, and 4 can be adopted.

[0030]

According to the present invention, since the structure of the rail is strengthened by the stay member and the vibration from the outside is attenuated, the vibration of the image forming unit can be reduced and the quality of the reproduced image can be improved. An image reading device can be provided.

[Brief description of drawings]

FIG. 1 is a perspective view illustrating a configuration of a main part of an image reading apparatus according to the present invention.

FIG. 2 is a plan view illustrating another example of the image reading apparatus according to the present invention.

FIG. 3 is a plan view illustrating still another example of the image reading apparatus according to the present invention.

FIG. 4 is a cross-sectional view when a stay member according to the present invention is used as a damping material.

FIG. 5 is a perspective view illustrating a configuration of a main part of an image reading apparatus suitable for implementing the present invention.

FIG. 6 is a perspective view illustrating a conventional rail structure.

FIG. 7 is a cross-sectional view of an essential part for explaining a combined state of an imaging unit and a rail.

FIG. 8 is a main-portion cross-sectional view for explaining a combined state of the imaging unit and the rail.

[Explanation of symbols]

13a rail 13 rails 15 Stay member 15-1 Stay member 15-2 Stay member 15-3 Stay member 15-4 Stay member 16 steel plate 17 Viscoelastic polymer material

Claims (2)

(57) [Claims] 1. A scanning direction comprising: a contact glass on which an original is placed; a lamp provided below the contact glass to illuminate the original on the contact glass; and a first mirror for changing an optical path of the original reflected light. And a second traveling body that moves in the scanning direction at a speed that is ½ of that of the first traveling body, and a first traveling body that moves to the first traveling body and a second mirror that further changes the optical path changed by the first mirror. And a pair of rails that guide the travel of at least one of the first traveling body and the second traveling body, and the reflected light whose optical path is changed by each mirror of the first traveling body and the second traveling body. An image reading unit in which the image forming unit that holds the image forming lens that emits light and the light receiving element that receives the condensed reflected light and the image forming unit are fixed between the pair of rails, Between a pair of rails, coupled with the stay members which gave damping function, in order to have the damping function to the stay member, steel
It is a sandwich structure in which a viscoelastic polymer material is sandwiched between plates.
An image reading apparatus using a restrained type vibration damping steel plate . 2. The image reading apparatus according to claim 1 , wherein the stay member is paired with a pair of rails in the longitudinal direction of the rails.
However, it is provided as a bridge by combining two intersecting members.
Image reading apparatus characterized by being.