JPH05276309A - Image reader - Google Patents

Abstract

(57) [Abstract] [Purpose] In an image reading device, in order to accurately form an image of an object on a sensor so that the sensor exhibits its performance, the sensor is simple and inexpensive in each of the X-axis, Y-axis, and rotation directions. Move to adjustable. [Structure] A lens block (2) supporting a lens (1)
A sensor holding plate (5), a guide plate (3) arranged between the lens block and the sensor holding plate, and the sensor holding plate provided on the guide plate for moving and adjusting in the X and Y directions. Two eccentric knobs (6a, 6b) for
Adjusting elongated holes (5a, 5b) for the eccentric knob, which are provided in the sensor holding plate and allow movement adjustment in the X direction, and the guide plate with respect to the lens block are adjusted in the rotation direction about the Y axis. An eccentric bush (11) is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading apparatus having a reduction optical system used in copying machines, facsimiles, scanners and the like.

[0002]

2. Description of the Related Art In the image reading apparatus, in order to accurately form an image of a target object on a sensor, the sensor is moved to the X-axis, Y-axis,
It is already known to allow movement adjustment in each direction of rotation (Japanese Patent Publication No. 55-36228).

However, the conventional luminous intensity adjustment is a two-dimensional adjustment in the X and Y directions, and the perpendicularity of the sensor to the optical axis depends on the precision of the parts. Further, there has been proposed a device further equipped with a rotation direction adjusting means around the Y axis, but this has a drawback that the mechanism is complicated and it is difficult to assemble.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to propose an image reading apparatus which solves the above-mentioned drawbacks in the prior art and enables simple and inexpensive light intensity adjustment.

[0005]

According to the present invention, the above-mentioned problems are arranged between a lens block for supporting a lens, a sensor holding plate for supporting a sensor, and the lens block and the sensor holding plate. A guide plate, two eccentric knobs provided on the guide plate for moving and adjusting the sensor holding plate in the Y direction, and an eccentric knob for the eccentric knob provided on the sensor holding plate and permitting movement adjustment in the X direction. This is solved by providing an adjusting elongated hole and one eccentric bush that adjusts the guide plate with respect to the lens block in the rotational direction around the Y axis.

Furthermore, the present invention proposes that the guide plate be adjustable in a rotational direction about an axis in the X direction in order to solve the above problems.

[0007]

By rotating the eccentric knob attached to the guide plate in the adjustment elongated hole provided in the sensor holding plate, the sensor holding plate, and thus the sensor carried by the sensor holding plate, moves in the Y direction relative to the guide plate.
The movement can be adjusted in the direction, that is, in the vertical direction. Since the sensor holding plate has the adjustment elongated hole for the eccentric knob provided on the guide plate, it can be moved in the lateral direction, whereby the sensor can be moved and adjusted in the X direction. Further, since the guide plate is rotated about the Y-direction axis by the eccentric bush, the movement of the sensor in the θy direction can be adjusted.

Furthermore, the sensor holding plate is arranged to rotate about an axis in the X direction, which results in a θ of the sensor.
Adjustment in the x direction can be possible.

[0009]

The present invention will be described below with reference to the embodiments shown in the drawings.

In FIG. 1, a lens 1 is supported by a lens block 2. Reference numeral 3 is a guide plate, 4 is a solid-state image sensor (hereinafter referred to as CCD sensor), and 5 is a sensor holding plate carrying the CCD sensor 4. The guide plate 3 is arranged between the lens block 2 and the sensor holding plate 5.

The sensor holding plate 5 includes two adjusting slots 5a and 5b for the eccentric knobs 6a and 6b, and a fixing screw 9a.
9b is provided with two holes 5c and 5d having an inner diameter larger than those of these fixing screws. 7a and 7b are mounting screws for the eccentric knobs 6a and 6b, and 8a and 8b are washers attached to the fixing screws 9a and 9b.
Has a larger diameter than.

The guide plate 3 is provided with an opening 3a substantially at the center thereof, which is large enough for the CCD sensor 4 carried by the sensor holding plate 5 to enter. In addition, the guide plate 3 has
Protrusions 33, 34 having screw holes 31, 32 for the mounting screws 7a, 7b and screw holes for the fixing screws 9a, 9b are provided. Further, a hole 35 for the concentric bush 10 and an adjustment groove 36 for the eccentric bush 11 are provided in the upper portion 3b of the guide plate 3 bent at a right angle. 12a, 1
2b is a concentric bush 10 and an eccentric bush 11 respectively.
Is a mounting screw for fixing to the lens block 2.

As shown in FIG. 2, by rotating the eccentric knobs 6a and 6b in the adjustment elongated holes 5a and 5b, the sensor holding plate 5 and thus the CCD sensor 4 carried by the sensor holding plate 5 are guided relative to the guide plate 3. The movement can be adjusted in the Y direction, that is, in the vertical direction. After completing this movement adjustment, set screw 7
The eccentric knobs 6a and 6b are fixed to their movement adjustment positions by a and 7b. Further, the sensor holding plate 5 is movable in the lateral direction, and by moving the sensor holding plate 5 in the lateral direction by hand, the movement adjustment of the sensor holding plate 5 in the X direction is performed. During this movement adjustment in the X direction, the eccentric knobs 6a and 6b move laterally in the adjustment elongated holes 5a and 5b, and during the movement adjustment in the X direction and the Y direction, the fixing screws 9a and 9b have relatively large holes 5.
Move within c and 5d.

As described above, the sensor 4 is operated in the X direction and the Y direction.
When the moiré waveform is observed after the movement adjustment in the direction, as shown in FIG. 4, the moiré waveform is not uniform left and right, but is often offset. In order to correct this, the adjustment shown in FIG. 3 is performed. That is, by rotating the eccentric bush 11 in the adjusting groove 36, the guide plate 3 rotates about the concentric bush 10 in the Y direction fixed to the lens block 2 by the mounting screw 12a, and the CCD sensor 4 is rotated. The movement adjustment in the θy direction can be performed. By this movement adjustment, the moire waveform can be made uniform as shown in FIG. This θ
After adjusting the movement in the y direction, attach the eccentric bush 11 to the mounting screw 12
The lens block 2 is clamped and fixed by b.

In the embodiment shown in FIG. 6, the guide plate 13
Has a fulcrum 14 in the X direction above it and is provided with a bent arm plate 13a below it.
An arc-shaped guide groove 37 centered on the fulcrum 14 is provided at a. The fixing screw 15 screwed into the lens block 2 is loosely fitted in the guide groove 37. As a result, the guide plate 13 rotates around the fulcrum 14, which is the axis in the X direction, and therefore the θx direction of the CCD sensor 4 can be adjusted. In this case, the arc-shaped guide groove 37 extends along the fixing screw 15. To move.

As shown in FIG. 7, when the movement adjustment of the CCD sensor 4 in the X direction, the Y direction and the θy direction described with reference to FIGS.
The light may be refracted at 6 and obliquely enter the sensor 4,
At this time, the performance of the sensor 4 cannot be fully exhibited. Therefore, at this time, the guide plate 3 shown in FIG. 1 is replaced with the guide plate 13 having the fulcrum 14 shown in FIG. 6, and a screw hole for the fixing screw 15 is provided on the side surface of the lens block 2. The guide plate 13 is rotated to an appropriate position around the fulcrum 14 so that the incident light is incident on the glass surface 16 of the sensor 4 at right angles as shown in FIG. 8, and then the fixing screw 15 is tightened. Thereby, the CCD sensor 4 is adjusted in the θx direction.

[0017]

According to the first aspect of the invention, since the optical adjusting mechanism is composed of a very small number of parts, the movement of the sensor in the X direction, the Y direction and the θy direction can be adjusted easily and inexpensively.

According to a second aspect of the invention, the sensor further comprises θ.
Since it is possible to make adjustments in four directions in addition to adjustments in the x direction, it is possible to prevent the decrease in light amount and to exert the sensor performance independently of the component accuracy.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of an image reading apparatus according to the present invention.

FIG. 2 is a view showing Y of a sensor in the image reading apparatus of FIG.
It is explanatory drawing of the movement adjustment of a direction.

3 is a view of θ of a sensor in the image reading apparatus of FIG.
It is explanatory drawing of movement adjustment of ay direction.

FIG. 4 is a diagram showing a non-uniform moire waveform before movement adjustment of the sensor in the θy direction.

FIG. 5 is a diagram showing a uniform moire waveform after movement adjustment of the sensor in the θy direction.

FIG. 6 is an explanatory view showing another embodiment of the present invention.

FIG. 7 is an explanatory diagram of incident light before movement adjustment of the sensor in the θx direction.

FIG. 8 is an explanatory diagram of incident light after movement adjustment of the sensor in the θx direction.

[Explanation of symbols]

 1 lens 2 lens block 3, 13 guide plate 4 CCD sensor 5 sensor holding plate 6a, 6b eccentric knob 10 concentric bush 11 eccentric bush 14 fulcrum

Claims (2)

[Claims] 1. An image reading apparatus having a reduction optical system, a lens block for supporting a lens, a sensor holding plate for supporting a sensor, and a guide plate arranged between the lens block and the sensor holding plate. , Two eccentric knobs provided on the guide plate for moving and adjusting the sensor holding plate in the Y direction, and adjusting elongated holes for the eccentric knob provided on the sensor holding plate and permitting movement adjustment in the X direction. And an eccentric bush that adjusts the guide plate in a rotational direction about an axis in the Y direction. 2. The guide plate is adjustable in a rotation direction about an axis in the X direction.
The image reading device described in 1.