JPH06237336A - Lens position adjustment mechanism in original reader - Google Patents

Abstract

PURPOSE:To prevent the effect on lens mount deflection by providing a cavity between a slot and a lens mount section of a lens movement mount base to allow the cavity to absorb the deflection of a tightening fixing section. CONSTITUTION:A position regulation section 69 formed to a lens movement mount base 6 is in press contact with a tip of an adjustment screw 92 and moved attended with the turning of the screw 92. When the forward/backward position of the mount base 6 is adjusted, screws 86, 88 are tightened to fix the mount base 6 to a base 10 and then the adjustment is made complete. The tightening fixing section of the mount base 6 is deflected by a tightening torque of the screws 86, 88 and the deflection acts in the direction of the lens mount section 60, but since cavity parts 66, 68 are respectively provided between slots 62, 64 and the lens mount section 60 forming the tightening fixing section, the deflection is absorbed by the cavity parts 66, 68. Thus, the effect of the deflection by the tightening torque is not given onto the lens mount section 60.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens position adjusting mechanism in a document reading device used in digital copying machines, facsimiles, scanners and the like.

[0002]

2. Description of the Related Art Conventionally, a document reading apparatus used in a digital copying machine, a facsimile or the like illuminates a document by relatively moving the document and a light source, and reflects light from the document on an image sensor by a lens. I am reading the original image.

An example of such a document reading device will be described with reference to FIG.

An optical system 2 for scanning and illuminating a document G placed on a document placing plate 11 which is a transparent plate is arranged in a main body 1 of the document reading device. The optical system 2 includes an illumination lamp 21 as a light source, a reflector 22, mirrors 23 and 24,
25, a lens 26, and an image sensor 27. The image sensor 27 is, for example, CC
A D type image sensor, a MOS type image sensor or the like is used. Then, the illumination lamp 21, the reflector 22 and the mirror 23 are integrally moved at a predetermined speed in the direction of the arrow A, and the mirrors 24 and 25 are integrally moved to the illumination lamp 21.
The original G placed on the original placing plate 11 is illuminated by moving the original G in the same direction at a speed half the moving speed, and the reflected light from the original G is reflected by the mirrors 23, 24, 25 ,. The light is guided to the image sensor 27 (shown by the optical path C in FIG. 5) through the lens 26.

In such a document reading device, in order for the image sensor 27 to correctly read the document, it is necessary that the image forming position of the lens 26 and the light receiving area of the image sensor 27 are exactly coincident with each other. Therefore, conventionally, the position of the image sensor and the position of the lens are adjusted while checking the original image received by the image sensor.

In the conventional lens position adjusting mechanism, a lens moving mount on which a lens is mounted is constructed so as to be movable in the direction of the image sensor, and the space between the two is adjusted to fix it to the base by a fixing means such as a screw. It is designed to be fixed by tightening. The lens moving mount 4 will be described in more detail with reference to FIG. 4. The lens moving mount 4 includes a lens mounting portion 40 formed in the central portion for mounting a lens,
Elongated holes 42 and 44 formed in parallel to each other are provided on both sides of the lens mounting portion 40, and are integrally molded of synthetic resin. Then, it is fastened and fixed to the base by fixing means such as screws which are inserted through the elongated holes 42 and 44.

[0007]

The lens moving mount 4 is made of synthetic resin in consideration of weight reduction and cost. Therefore, when the lens moving mount 4 is tightened and fixed by screws, the lens moving mount 4 is bent by the tightening force. This occurs, and this acts on the lens mounting portion to change the positional relationship of the lens mounting portion, and the correlation position between the lens and the image sensor slightly changes, and there is a problem that readjustment is necessary.

In order to solve such a problem, a lens moving mount made of aluminum and die-cast aluminum is also in practical use. However, the aluminum die-cast product is more expensive than the synthetic resin and has a problem that the weight is heavy.

The present invention has been made in view of the above points, and its main technical problem is to effectively absorb the bending generated in the tightening and fixing portion of the lens moving mount by tightening and fixing with a screw or the like. With the configuration, it is possible to use a synthetic resin, and to provide a lightweight and inexpensive lens position adjusting mechanism in an original reading apparatus.

[0010]

In order to achieve the above technical object, according to the present invention, a document reading device is configured so that a document is illuminated and scanned and reflected light from the document is guided to an image sensor by a lens. The lens moving mount having a lens mounting portion formed in a central portion for mounting the lens and elongated holes formed on both sides of the lens mounting portion in parallel with each other, In the lens position adjusting mechanism in the document reading apparatus, which is adjusted and fixed to the base by the fixing means inserted through the hole, a cavity is provided between the lens mounting portion and the elongated hole in the lens moving mount. ,
A lens position adjusting mechanism in a document reading device is provided.

[0011]

In the lens position adjusting mechanism of the document reading apparatus according to the present invention, the bending caused by the tightening and fixing of the lens moving mount due to the fixing and fixing by the fixing means inserted through the elongated hole is the lens mounting portion. Is effectively absorbed by the cavity provided between the hole and the slot, and the influence of the bending on the lens mounting portion is eliminated.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A detailed description will be given below with reference to the accompanying drawings showing a preferred embodiment of a lens position adjusting mechanism in a document reading apparatus constructed according to the present invention.

FIG. 1 is a plan view showing an embodiment of a lens position adjusting mechanism according to the present invention, FIG. 2 is a perspective view thereof, and FIG. 3 is an embodiment of a lens moving mount used in the lens position adjusting mechanism according to the present invention. FIG. In the drawing, reference numeral 6 denotes a lens moving mount of a lens position adjusting mechanism, which is formed in a central portion of the lens mounting portion 60 on which the lens 26 is mounted, and is formed on both sides of the lens mounting portion 60 in parallel with each other. Slot 6
2 and 64, cavity portions 66 and 68 provided between the lens mounting portion 60 and the long holes 62 and 64, respectively, and a position regulating portion 69 formed on one side portion. Are integrally molded by. The lens mounting portion 60 is formed so as to project upward, the central portion thereof is formed in a V-shaped cross section, and is provided with lens mounting surfaces 602 and 604.
Screw holes 606 and 608 are provided on both sides of the one end. In the lens moving mount 6 configured as described above, the lens 26 is mounted on the lens mounting surfaces 602 and 604 of the lens mounting portion 60, and the clip 8 is attached to one end of the lens 26, and the clip 8 The lens 26 is mounted and fixed by tightening and fixing it with screws 82 and 84 which are screwed into the screw holes 606 and 608 formed in the lens mounting portion 60. Further, the lens moving mount 6 includes the elongated holes 62, 64.
Is fixed to the base 10 by fixing means such as screws 86 and 88 which are screwed into screw holes (not shown) provided in the base 10. Reference numeral 90 in the drawing denotes a return spring stretched between the lens moving mount 6 and the bracket 102 provided on the base 10, and always urges the lens moving mount 6 to move downward in FIG. There is. 92 is a screw hole provided in the bracket 102 (not shown)
The tip of the adjusting screw is screwed into the position adjusting portion 69 formed on the lens moving mount 6 to regulate the position of the lens moving mount 6.

Next, the position adjusting mechanism of the image sensor 27 will be described. The image sensor 27 is fixed to a sensor mounting plate 28, and the sensor mounting plate 28 has a height adjusting plate 29.
It is attached by a fixing means such as a screw. The height adjusting plate 29 is provided with mounting portions 292, 294 bent in the horizontal direction at both ends thereof.
2, 294 mounting portion 30 provided on the adjustment mounting plate 30
It is mounted on Nos. 2 and 304, and adjusting screws 33 and 34 are screwed between the two via springs 31 and 32, whereby the adjustment mounting plate 30 is adjusted and fixed. The adjustment mounting plate 30 is arranged on the base 10 and is fixed and adjusted so as to be rotatable about a pin 35 inserted through the central portion thereof and movable in the left and right directions in FIG. That is, one end portion of the adjustment mounting plate 30 is provided with a long hole 296 in the left-right direction in FIG. 2, and the other end portion is provided with a long hole 298 in the up-down direction in FIG. Eccentric cams 36, 3
Seven eccentric shafts 362 and 372 are fitted together. Therefore,
By rotating the eccentric cam 36, the adjustment mounting plate 30
Is rotated about the pin 35, and the eccentric cam 37 is rotated to move the adjustment mounting plate 30 in the left-right direction in FIG.
The positional relationship with 6 is adjusted. When the positional relationship with the lens 26 is adjusted in this way, the adjustment mounting plate 30
Is fixed to the base 10 by screws 38 and 39 at both ends thereof.

Next, the adjusting operation of the above-mentioned lens position adjusting mechanism will be described.

When adjusting the positional relationship between the lens 26 and the image sensor 27, first loosen the screws 86 and 88 and rotate the adjusting screw 92 to move the lens 26 on the lens moving mount 6 in the front-back position. Adjust. During this adjustment, the lens moving mount 6 is always urged by the return spring 90 so as to move downward in FIG. 2, so that the position regulating portion 69 formed on the lens moving mount 6 causes the tip of the adjusting screw 92 to move. And moves as the adjusting screw 92 moves back and forth. After the front and rear positions of the lens moving mount 6 are adjusted, tighten the screws 86 and 88 to move the lens moving mount 6.
By fixing the to the base 10, the adjustment work is completed. The tightening force of the screws 86 and 88 causes the tightening and fixing portion of the lens moving mount 6 to bend, and this bending also acts in the direction of the lens mounting portion 60. , 64 and the lens mount 60 between the cavity 6
6 and 68 are provided, the cavity portions 66 and 6 are
The bending is absorbed by 8. Therefore, the lens mount 60 is not affected by the bending due to the tightening force.

[0017]

The lens position adjusting mechanism according to the present invention is configured as described above, and since the cavity is provided between the lens mounting portion and the elongated hole in the lens moving mount, the position of the lens moving mount can be adjusted. When adjusting and fixing, even if bending occurs in the tightening and fixing portion due to the tightening force of the fixing means that inserts through the elongated hole and tightens, the bending is absorbed by the cavity portion, so the lens mounting portion It is possible to prevent the influence of the flexure on the above. Therefore, it is possible to use a synthetic resin having a relatively low rigidity as a material for the lens moving mount, and it is possible to obtain a lightweight and inexpensive lens position adjusting mechanism in the original reading apparatus.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of a lens position adjusting mechanism according to the present invention.

FIG. 2 is a perspective view of the lens position adjusting mechanism shown in FIG.

FIG. 3 is a perspective view showing an embodiment of a lens moving mount used in the lens position adjusting mechanism shown in FIG.

FIG. 4 is a perspective view of a conventional lens moving mount.

FIG. 5 is a schematic cross-sectional view showing the internal structure of the document reading device.

[Explanation of symbols]

 2: Optical system 6: Lens moving mount 26: Lens 27: Image sensor 28: Sensor mount plate 29: Height adjusting plate 30: Adjusting mount plate 36: Eccentric cam 37: Eccentric cam 60: Lens mount 62 : Slot 64: Slot 66: Cavity 68: Cavity

Claims (1)

[Claims] 1. A document reading device configured to illuminate and scan a document and guide light reflected from the document to an image sensor by a lens, comprising a lens mounting portion formed in a central portion for mounting the lens. In a document reading device, a lens moving mount having elongated holes formed on both sides of the lens placement portion in parallel with each other is adjusted and fixed to a base by fixing means inserted through the elongated holes. In the lens position adjusting mechanism, a cavity is provided between the lens placing part and the elongated hole in the lens moving mount, wherein the lens position adjusting mechanism in the original reading device.