JPH0244960A - Picture reader - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an image reading device, and more particularly to an image reading device in which an optical system moves to read an image of a stationary document.

(Prior Art) An image reading device in which an optical system moves to read a stationary image is often applied to a scanner section of a facsimile machine, a general-purpose scanner, and even a scanner section of a copying machine.

Conventionally, as such an image reading device, for example, a fourth image reading device has been used.
There is something like the one shown in the figure.

FIG. 4 is a diagram showing a drive system of an optical system of a scanner device as an image reading device, and the scanner device 1 is connected to the first traveling body 2.
and a second running body 3.

The first traveling body 2 and the second traveling body 3 are guided movably in the sub-scanning direction (arrow direction in FIG. 4) by a guide member (not shown), and the first traveling body 2 includes a light source and a light source. The first member introduces the reflected light of the light projected onto the document from the first member into the second traveling member 3.
A mirror (first mirror body) is mounted. The second traveling body 3 is equipped with a second mirror body consisting of a second mirror and a third mirror, the second mirror introduces the light from the first mirror to the third mirror, and the third mirror The light from the two mirrors is introduced into a photoelectric conversion means (image forming means) not shown. As the photoelectric conversion means, for example, CCD (Charge
Coupled Device), etc., and converts incident light into an electrical signal.

The first traveling body 2 is engaged with a wire 4 stretched in the sub-scanning direction, and the second traveling body 3 is engaged with the wire 4 via a pulley (deceleration means) 5.

The wire 4 is wound around the pulley 5 of the second running body 3 from a fixed end 6 of the frame or the like of the scanner device 1, and then connected to the first running body 2, guided by the guide pulley 7, and connected to the drive pulley of the drive motor. It is wound around 8. The wire 4 wound around the drive pulley 8 is guided to the guide pulley 9 and then judged by the reversing pulley 10, and the inverted wire 4 is wound around the pulley 5 and then fixed to the frame of the scanner device 1, etc. It is fixed to the end 11 via a spring 12.

Therefore, the first traveling body 2 and the second traveling body 3 move in the same sub-scanning direction as the wire 4 moves by rotationally driving the drive pulley 8 by the drive motor, and the second traveling body 3 moves in the same sub-scanning direction. 5, the first traveling body 2
move at half the speed of As a result, the optical path length from the light source to the photoelectric conversion means can be kept constant.

(Problem to be Solved by the Invention) However, in such a conventional image reading device, the wire 4 guided by the guide pulley 7 and the reversing pulley is stretched in the sub-scanning direction, and the first In addition to fixing the traveling body 2 and engaging the second traveling body 3 via a deceleration pulley, a drive pulley 8 for driving is also used.
As the drive pulley 8 rotates, the first
Since the traveling body 2 and the second traveling body 3 are sub-scanned, the wire 4 is long, and the wire 4 expands and contracts under the influence of temperature. Therefore, in order to absorb the elongation and contraction of the wire 4, it is necessary to connect the springs 12 to the wire 4, and the load fluctuations when the first traveling body 2 and the second traveling body 3 are moved, and the first traveling body 2 and the The position of the first traveling body 2 and the second traveling body 3 is changed due to the vibration of the blades 12 due to the star I and stop of the second traveling body 3, and the movement accuracy of the first traveling body 2 and the second traveling body 3 is The problem was that it was bad.

In addition, since the sub-scanning of the first traveling body 2 and the second traveling body 3 was performed by moving the wire 4 wound around the drive pulley 8 and the pulley 5 by driving the drive pulley 8, each pulley and the wire 4 There was a problem that slipping occurred between the two, resulting in poor movement accuracy.

Therefore, conventionally, in order to reduce the effect of slipping between the pulley and the wire 4 on movement accuracy, the wire 4 has been wound around the pulley 5 and the drive pulley 8 multiple times, but the slipping has been sufficiently eliminated. However, image reading devices as shown in FIGS. 5(a) to 5(c) are also provided.

This image reading device 21 has a fixed frame 22 having a U-shaped cross section in the sub-scanning direction, and a first frame 24 is housed in the fixed frame 22 so as to be movable in the sub-scanning direction via rollers 23a and 23b. has been done. Also, a second frame 2 is inserted into the first frame 24 via rollers 25a and 25b.
6 is housed so as to be movable in the sub-scanning direction. and,
As shown in FIGS. 5(b) and (C), this first frame 2
A first traveling body 27 is mounted on the frame 4, and a second traveling body 28 is mounted on the second frame 26.

However, in such a conventional image reading device 21, the second frame 26 passes through the first frame 24.
Since the traveling body 27, that is, moves at half the speed of the first frame 24, it is necessary to make the first frame 24 long, which increases the size of the image reading device 21 and increases the mass of the first frame 24. This becomes an inertial load and affects the movement of the first frame 24 and the second frame 26, that is, the movement of the first traveling body 27 and the second traveling body 28. Furthermore, there is a possibility that slippage may occur between the first frame 24 and the second frame 26. As a result, the first traveling body 27
There was a problem that the movement accuracy of the second traveling body 28 was poor.

(Object of the Invention) Therefore, the present invention engages a first traveling body with a movable body moving in the sub-scanning direction, engages a second traveling body with the same movable body via a deceleration means, and By configuring the deceleration means with a rotating body that engages with the moving body and rotates, and a regulating means that restricts the rotation of the rotating body and moves the second moving body, the optical system can be easily moved. Moreover, with a structure that does not cause slippage, the purpose is to make the image reading device smaller and lower in price, and to improve the movement accuracy of the first traveling body and the second traveling body, thereby improving the image quality. .

(Structure of the Invention) In order to achieve the above object, the present invention includes a light source that irradiates a document with light, an image forming means that receives light including image information and converts it into an image, and a light source that irradiates light including image information and converts the light reflected from the document into an image. a mirror group introduced into the image forming means, the mirror group having a first mirror body and a second mirror body, the first mirror body introducing reflected light from the document to the second mirror body, A second mirror body introduces light from the first mirror body to the image forming means, the light source and the first mirror body are mounted on the first traveling body, the second mirror body is mounted on the second traveling body, and the second mirror body is mounted on the second traveling body. In an image reading device in which a first traveling body and a second traveling body move differentially while maintaining a constant distance from a light source to an image forming means, the first traveling body is engaged with a movable body that is rotationally driven and moves in a sub-scanning direction. The second traveling body engages with the same moving body via a deceleration means, and the deceleration means engages with the movable body and rotates the rotary body, and the second traveling body restricts the rotation of the rotary body. The present invention is characterized in that it is formed by a regulating means for moving the traveling body.

Hereinafter, the present invention will be specifically explained based on examples.

1 to 3 are diagrams showing an embodiment of the present invention, which is applicable to a scanner device.

FIG. 1 is a diagram showing a scanner device 31, in which a contact glass 33 is attached to the upper part of a case 32 of the scanner device 31. As shown in FIG. A document is set on the contact glass 33 with the document surface facing the contact glass 33, and the document is held against the contact glass 33 by the document holder 34.
be held down by

An optical system is housed inside the scanner device 31, and the optical system includes a light source 35, a first mirror (first mirror body) 36,
It is composed of a second mirror 37, a third mirror 38, a lens 39, a photoelectric conversion means 40, and the like. The second mirror 37 and the third mirror 38 constitute a second mirror body 41.

The light source 35 irradiates the document with light through the contact glass 33 , and the first mirror 36 receives the reflected light from the document and reflects it onto the second mirror 37 . The second mirror 37 reflects the light from the first mirror 36 to the third mirror 38, and
8 reflects the incident light toward lens 39 . lens 3
9 focuses the incident light onto the photoelectric conversion means 40 . The photoelectric conversion means 40 is, for example, a CCD (Charge Co.
It divides incident light into a plurality of pixels, performs photoelectric conversion, and outputs it as image data.

The light source 35 and the first mirror 36 are mounted on a first traveling body 42 shown in FIG.
The mirror 37 and the third mirror 38 are mounted on a second traveling body 43 shown in FIG. The first traveling body 42 and the second traveling body 43 are arranged long in the main scanning direction, and both ends thereof are slidably supported by a guide shaft 44 . A guide shaft 44 is disposed in the sub-scanning direction, and the first traveling body 42 and the second traveling body 43 move along this guide shaft 4.
4 and moves in the sub-scanning direction.

The first traveling body 42 is connected to a timing heald (moving body) 46 via an arm 45 attached to its end in the main scanning direction.
The timing heald 46 is tensioned between a guide pulley 47 and a drive pulley 48. The guide pulley 47 and the drive pulley 48 are arranged at one end and the other end of the scanner device 31 in the sub-scanning direction, and therefore the timing heald 46 is arranged to extend in the sub-scanning direction. . timing held 4
Teeth are formed on the inner surface of guide boo U-4.
7 and the drive pulley 48 are provided with teeth that mesh with the teeth of the timing heald 46 . A shaft 49a of a drive motor 49 is connected to the drive pulley 48, and when the drive pulley 48 is rotated by the drive motor 49, the timing heald 46 rotates (moves in the sub-scanning direction) due to the rotation of the drive pulley 48.

On the other hand, a pulley (rotating body) 50 having teeth formed on its outer periphery is attached to the end of the second traveling body 43 in the main scanning direction. They fit together. In addition, the second traveling body 43
The timing belt 46 is connected between the pulley 50 and the end of the timing belt 46.
A pressure roller 51 is attached at a position sandwiching the timing belt 4G.
is pressed in the direction of the pulley 50 to ensure meshing between the timing heald 46 and the pulley 50.

Furthermore, a regulation rail 52 is arranged between the guide pulley 47 and the drive pulley 48 in the sub-scanning direction, and the regulation rail 52 is fixed to the frame of the scanner device 31 or the like. Upper surface of regulation rail 52 (surface on pulley 50 side)
is formed with teeth that mesh with the pulley 50, and the pulley 50 meshes with the timing belt 46, and
It also meshes with the regulation rail 52. Therefore, the pulley 50 rotates on the regulation rail 52 as the timing heald 46 moves, and moves the second traveling body 43 in the sub-scanning direction.

Note that the timing belt 46 is connected to the first and second running bodies 4.
2.43 may be arranged on both sides or only on one side.

Next, the action will be explained.

The scanner device 31 uses a contact glass 3 when reading an image.
Light is projected from the light source 35 onto the original set on the document 3, and the reflected light is guided to the charge conversion means 40 via the first mirror 36, second mirror 37, third mirror 3B and lens 39, and the photoelectric conversion means 40 performs photoelectric conversion to perform main scanning, and also drives a drive motor 49 to move the first traveling body 42 and the second traveling body 43 in the sub-scanning direction.

That is, when the drive pulley 48 is rotated by the drive motor 49, the timing belt 46 is moved in the main scanning direction by the rotation of the drive pulley 48, and when the timing belt 46 is moved, the first The traveling body 42 moves together with the timing helmet 46. At this time, since the drive pulley 48 and the timing heald 46 are in mesh with each other, no slipping occurs (
, the timing heald 46 is reliably moved in the sub-scanning direction by the rotation of the drive pulley 48.

On the other hand, the pulley 50 rotates as the timing belt 46 moves, and the pulley 50 moves on the regulation rail 52 as it rotates. Therefore, the pulley 50 moves on the regulation rail 52 by an amount (distance) that is half the amount (distance) of movement of the timing belt 46 with respect to the regulation rail 52. That is, as shown in FIG. 3, if the timing belt 46 moves by ■5 with respect to the pulley 50, the pulley 50
, it rotates and moves a certain distance on the regulation rail 52. Therefore, the pulley 50 moves a great distance on the regulation rail 52, and the timing heald 46 moves on this pulley 50.
Move by L with respect to. As a result, the timing heald 46 moves by 2L with respect to the regulation rail 52. Therefore, when the timing heald 46 moves 2L relative to the regulation rail 52, that is, when the first traveling body 42 moves 2L relative to the regulation rail 52, the pulley 50
The second traveling body 43 moves as much as possible with respect to the regulation rail 52, and the second traveling body 43 moves by one-half of the moving distance of the first traveling body 42. That is, the second traveling body 43
is moved at a speed reduced to half that of the first traveling body 42 by the pulley 50 and the regulation rail 52, and the pulley 5
0 and the regulation rail 52 constitute a deceleration means 53 as a whole. As a result, the optical path from the light source 35 to the photoelectric conversion means 40 is always kept constant. The pulley 50 and the timing heald 46 are held together by meshing teeth formed on both, and the pulley 50 and the regulating rail 52 are engaged with each other.
The engagement between the two is also achieved by the meshing of teeth formed on both.

Therefore, no slipping occurs, and the movement accuracy of the first traveling body 42 and the second traveling body 43 is improved. In addition, the timing heald 46 is connected to the pulley 5 by the pressure roller 51, and the timing heald 46 and the pulley 50 are engaged with each other.
By being pressed in the zero force direction, it becomes even more reliable, and the movement accuracy of the second traveling body 43 is further improved. As a result, the accuracy of image reading by the scanner device 31 is improved, and the quality of the read image is improved.

Furthermore, since the timing heald 46 is only tensioned between the guide pulley 47 and the drive pulley 48, the scanner device 31 can have a simple structure, making the scanner device 31 inexpensive. be able to.

In addition, since the timing heald 46 and the drive pulley 48, the timing heald 46 and the pulley 50, and the pulley 50 and the regulation rail 52 are engaged by meshing, in order to tension the timing heald 46, a spring or the like is used as in the conventional method. does not require. As a result, the movement of the first traveling body 42 and the second traveling body 43 can be further stabilized, and the movement accuracy of the first traveling body 42 and the second traveling body 43 can be further improved.

Although the above embodiments have been described as being applied to a scanner device, the present invention is not limited to this, and can be applied to general image reading devices such as facsimile machines and copying machines.

Further, in the above embodiment, the photoelectric conversion means 40 was employed as the image forming means, but the invention is not limited to this.
In analog copiers such as copying machines, recording media such as photoreceptors are used.

(Effects) According to the present invention, it is possible to prevent slippage in the drive system of the optical system of an image reading device, and it is possible to improve the accuracy of sub-scanning of the optical system.

As a result, the quality of the image read by the image reading device can be improved.

Further, the structure of the drive system of the optical system of the image reading device can be simplified and downsized, and the image reading device can be downsized and inexpensive.

[Brief explanation of the drawing]

1 to 3 are diagrams showing an embodiment of an image reading device of the present invention, FIG. 1 is a side sectional view of a scanner device to which the image reading device is applied, and FIG. 2 is an optical drive system thereof. FIG. 3 is an explanatory view of the operation of the deceleration means. FIG. 4 is a perspective view of an optical drive system of a conventional image reading device. 5(a) to 5(C) are views showing other conventional image reading devices, respectively. FIG. 5(a) is a sectional view of the main part thereof, and FIGS. 5(b) and 5(C) are respective views thereof. It is an action explanatory diagram. 31... Scanner device, 35... Light source, 36... First mirror (first mirror body), 40...
...Photoelectric conversion means, 42...First running body, 43...Second running body, 46...Timing belt (moving body), 47...
... Guide pulley 48 ... Drive pulley 49 ... Drive motor,

Claims (1)

[Claims] A light source that irradiates a document with light, an image forming means that receives light containing image information and converts it into an image, and a mirror group that introduces reflected light from the document into the image forming means, the mirror group has a first mirror body and a second mirror body, the first mirror body introduces reflected light from the original into the second mirror body, and the second mirror body
a mirror body introduces light from the first mirror body to the image forming means, the light source and the first mirror body are mounted on a first traveling body,
In an image reading device in which a second mirror body is mounted on a second traveling body, and the first traveling body and the second traveling body move differentially while maintaining a constant distance from a light source to an image forming means, the first traveling body Rotation in which the second traveling body engages with a movable body that is rotationally driven and moves in the sub-scanning direction, the second traveling body engages with the same movable body via a deceleration means, and the deceleration means engages and rotates with the movable body. An image reading device comprising: a body; and a regulating means for regulating the rotation of the rotating body and moving the second traveling body.