JP2001148761A - Optical reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate reduction adjusting which is troublesome in optical adjusting and to prevent a defective reduction adjustment from. SOLUTION: The optical reader which is equipped with a light source, a lens 3, and a photoelectric converting element 4 and reads an image on a surface to be read is equipped with reduction movement transmitting means 51 and 64 which finely move a lens block 6 fitted with the lens 3 and photoelectric converting element 4 by reducing and transmitting a movement quantity so as to adjust reduction between the surface to be read and photoelectric converting element 4 by finely moving the lends block 6 to and away from the surface to be read.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical reading apparatus for reading image information, for example, used for an electronic blackboard, a scanner, a copying machine, and the like.

[0002]

2. Description of the Related Art For example, scanners, copiers, electronic blackboards and the like are provided with an optical reader for optically reading image information.

[0003] These optical readers include, for example, a light source, a lens as an image forming means, and a CC as a photoelectric conversion element.
D (charge-coupled device) and the like are known, but in order to read image information satisfactorily with them, for example, optical adjustment such as scan line adjustment, focus adjustment, and reduction ratio adjustment is required. It is.

By the way, among these optical reading devices, those of a type used for a scanner or a copier, for example, the size of a document is not so large.
The size ratio between the original (reading surface) and the photoelectric conversion element (imaging surface), that is, the reading reduction ratio, can be relatively small, for example, about 10: 1. Therefore, in such a type of optical reading device, not so high precision is required for the reduction ratio adjustment, which is one of the optical adjustments, the reduction ratio adjustment is relatively easy, and automation is also possible. .

On the other hand, as for an optical reading device of a type used for an electronic blackboard device or the like, as shown in FIG.
A light source 100 and a mirror 101 attached to a frame F of the electronic blackboard device; a lens block 102 attached to an optical base 105 of the frame F;
2 and a photoelectric conversion element such as a CCD (not shown) mounted on a photoelectric substrate 104 fixed to the lens block 102.

However, in such an optical reading apparatus, the size of a writing area such as a blackboard (surface to be read) is large, but the size of a photoelectric conversion element (imaging surface) such as a CCD is large. Is small. Therefore, the reading reduction ratio is, for example, 5
It is as large as about 0: 1, and high precision is required for the reduction ratio adjustment, which is one of the optical adjustments.

Therefore, it has been considered to reduce the required accuracy by increasing the size of the optical reading device and to automate the reduction ratio adjustment. However, when the size is increased, the optical reading device cannot be accommodated in the electronic blackboard device. There is a fear. Under such circumstances, in an electronic blackboard device provided with an optical reading device having a large reading reduction ratio, automatic adjustment is practically impossible.

Therefore, in such an optical reading apparatus, for example, a long hole (not shown) parallel to the front-back (X) direction of the lens block 102 is formed, and the lens is inserted by a screw inserted into the long hole. Block 102 is replaced with optical base 10
One that has been fixed to 5 has been developed. In the optical reading device having such a configuration, when performing the reduction ratio adjustment, the screw fixing the lens block 102 is loosened, and the lens block 102 is moved by hand in the forward and backward (± X) directions. .

[0009]

However, in such an optical reading apparatus having a high reading reduction ratio, if the reduction ratio adjustment is manually performed, the reading width of the photoelectric conversion element is changed to the mirror which is the surface to be read. It was difficult to match the reference reading width W in 101.

That is, since such a reduction ratio adjustment operation is performed by directly moving the lens block 102 with respect to the optical base 105 by hand, a delicate force adjustment is required. In particular, as the reduction ratio becomes higher, the width W to be read changes greatly even if the lens block 102 is moved slightly back and forth.

[0011] Under such circumstances, in the optical reading device with a high reduction ratio, a large variation occurs in the reading reduction ratio of each product, and a large number of defective products are generated without being within the predetermined allowable range. At the same time, it took time to adjust the reduction ratio.

In view of the above circumstances, the invention according to claim 1 can easily perform a reduction ratio adjustment operation that is troublesome in the optical adjustment operation. It is an object of the present invention to prevent occurrence of defective products having poor quality.

A second aspect of the present invention has a relatively simple structure, and an object of the present invention is to make it possible to easily perform a reduction ratio adjustment operation.

It is an object of the invention according to a third aspect that the reduction ratio can be easily adjusted even by a manual operation.

According to a fourth aspect of the present invention, it is possible to prevent the rack portion and the pinion portion from meshing with each other, causing abnormal noise and vibration at the meshing portion, and loosening of the lens block. The purpose is to prevent it.

A fifth object of the present invention is to provide a reliable and stable contraction rate adjustment operation.

[0017]

According to a first aspect of the present invention, there is provided an optical reading apparatus for reading an image on a surface to be read, comprising a light source, a lens, and a photoelectric conversion element. The fine movement of the lens block on which the lens block is attached with respect to the surface to be read and the reduction movement transmission for finely moving the lens block by reducing the amount of movement in order to adjust the reduction ratio between the surface to be read and the photoelectric conversion element. Means.

According to a second aspect of the present invention, in the first aspect of the present invention, a rack and pinion mechanism having a pinion portion and a rack portion meshing with the pinion portion is used as the reduction movement transmitting means.

According to a third aspect of the present invention, in the second aspect of the present invention, a knob portion which is pinched by a finger is integrally attached to a pinion portion of the rack and pinion mechanism, and the rack portion is moved by operating the knob portion. , So as to adjust the reduction ratio.

According to a fourth aspect of the present invention, in the second or third aspect of the present invention, there is provided a shrinkage ratio adjusting knob in which a pinion portion and a knob portion are integrated, and a stepped through hole provided in the shrinkage ratio adjusting knob. A screw inserted into the hole is provided, and the shrinkage adjustment operation is performed with the screw loosened, and after the completion of the shrinkage adjustment work, the screw is tightened to fix the shrinkage adjustment knob and the lens block. Things.

According to a fifth aspect of the present invention, in the first aspect of the present invention, an elongated hole for guiding a moving operation of the power transmission mechanism is formed in the lens block. A screw that engages with the long hole is provided, and when the lens block is finely moved by the rack and pinion mechanism, the lens block is guided by the screw that engages with the long hole.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the accompanying drawings. FIG. 1 is a schematic configuration diagram showing an optical reading device according to the present invention provided in an electronic blackboard device.
The optical reading device includes an optical system A and an optical adjustment unit B that performs optical adjustment of the optical system A. In FIG. 1, reference symbol S indicates an endless sheet in which information spanned between the driving roller 11 and the driven roller 12 is written by hand.

The optical system A includes a light source 1, a mirror 2, a lens 3, and a photoelectric conversion element 4 as in the conventional optical system, and drives the drive roller 11 with a drive motor (not shown). When the endless sheet S is transported, the information written on the endless sheet S is read.

That is, in the optical system A, the reading light is projected from the light source 1 toward the endless sheet S, and the reading light reflected there is made incident on the mirror 2 and reflected by the mirror 2 as in the conventional case. After transmitting the reflected light through the lens 3, an image is formed on the photoelectric conversion element 4, and an electric signal corresponding to the information written on the endless sheet S is obtained.

As shown in FIGS. 2 and 3, the optical adjustment means B includes an optical base 5, a lens block 6, a photoelectric substrate 7, and a rack and pinion mechanism 8 as a reduction movement transmitting means. Are unitized as a lens block unit.

The optical base 5 is fixed to a frame of an electronic blackboard device (not shown) in an immovable state, and a lens block 6 is attached to the optical base 5 so as to be finely movable in the forward and backward (± X) directions. The optical base 5 is also provided with a contraction ratio adjustment knob 51 that is manually operated to finely adjust the lens block 6.

As shown in FIG. 4A, the contraction ratio adjustment knob 51 has a pinion 51A and a knob 51B. As shown in FIG. The stepped screw 52 is inserted into the provided stepped through-hole 51 </ b> C and screwed to the optical base 5. When the stepped screw 52 is loosened, the contraction rate adjustment knob 51 becomes rotatable with respect to the optical base 5.

As shown in FIG. 3, the lens 3 is fixed to the lens block 6 at the distal end with a fixing screw 31, and the photoelectric substrate 7 is vertically (± Y), right and left (± It is mounted to be movable in ± Z) directions. further,
The lens block 6 has a mounting portion 61 at an upper portion and a lower portion.
The upper end surface and the lower end surface of the mounting portion 61 are provided with a toothed rack portion 64. The mounting portions 61 on both the upper and lower sides of the lens block 6 are provided with long holes 62 parallel to the horizontal (X) direction, respectively, and set screws 63 inserted into these long holes 62. The lens block 6 is fixed to the optical base 5 by tightening.

Further, the lens block 6 is provided at the base end thereof with a second mounting portion 65 orthogonal to the mounting portion 61, and the second mounting portion 65 is provided with a photoelectric substrate 7
Are mounted, internally threaded bosses 65A and 65B are secured.

On the photoelectric substrate 7, the set screw 72 and the mounting screw 74 of the scan line adjustment knob 73 are screwed into the bosses 65A and 65B from above the optical substrate 7, respectively, to the second mounting portion 65 of the lens block 6. It is designed to be fixed. The photoelectric substrate 7, which is a photoelectric conversion element 4 using a CCD, is mounted on the photoelectric substrate 7, and the upper and lower portions avoiding the mounting portion of the photoelectric conversion element 4 are parallel to the vertical (Y) direction. , A pair of elongated holes 71 are formed, and the scan line adjustment knob 73 inserted into the elongated hole 71 with the photoelectric substrate 7 temporarily fixed to the second mounting portion 65.
Is used to perform scan line adjustment.

As shown in FIGS. 5 and 6, the scan line adjustment knob 73 is provided with a hole 73A through which a mounting screw 74 penetrates, and at the lower part of a knob 73B provided on the outer peripheral surface, a photoelectric switch is provided. A cam portion 73C that engages with the long hole 71 of the substrate is formed.

The cam portion 73C constitutes an eccentric cam and has a major axis (R1) and a minor axis (R2).
When the scan line adjustment knob 73 is rotated around the mounting screw 74 (with the tightened state loosened) as a rotation axis, for example, as shown in FIG. When abutting on the right edge of the elongated hole 71, the upper side of the optical substrate 7 is pushed rightward (−Z direction) by the amount of eccentricity of the cam portion 73 </ b> C with respect to the lens block 6 fixed to the optical base 5. To move.

When performing the scan line adjustment operation, the scan line adjustment knob 73 is inserted into the long hole 71, and the hole 73 of the scan line adjustment knob 73 is further inserted.
The mounting screw 74 inserted in A may be loosely screwed into the boss 65B. Thereby, the photoelectric substrate 7 can be freely slid in the vertical (± Y) and left / right (± Z) directions with respect to the second mounting portion 65 of the lens block 6. The set screw 72 is preferably loosely screwed into the boss 65A, though it depends on the size of the hole 75 formed on the photoelectric substrate 7 side.

That is, when performing scan line adjustment, the photoelectric substrate 7 is fixed to the fixed lens block 6.
Are temporarily fixed so as to be movable in the vertical (± Y) and left / right (± Z) directions.
By sliding in the left and right direction, the image forming position of the read image projected on the mirror 2 is adjusted. After the scan line adjustment is performed on the photoelectric substrate 7, the set screw 72 and the mounting screw 74 are connected to the bosses 65A and 65A of the lens block 6.
5B, and fix the photoelectric substrate 7 firmly.

The rack and pinion mechanism 8 comprises a rack portion 64 provided on the lens block 6 side and a pinion portion 51A provided on the shrinkage ratio adjusting knob 51 engaged with the rack portion 64, and particularly accurate adjustment is required. Can be easily adjusted by rotating the knob 51B. In addition, a mechanism such as a ball screw may be used as the reduction movement transmitting means, in addition to the rack and pinion mechanism.

Next, an optical adjustment method using the optical reader will be specifically described. Prior to the optical adjustment, all the optical elements of the optical system A are all attached to predetermined members of the optical adjustment means B.

First, regarding the scan line adjustment, as shown in FIG.
After the optical base 7 is loosened and the optical base 7 is temporarily fixed, the scan line adjusting knob 73 is operated to move the photoelectric substrate 7 vertically by the action of the eccentric cam, and the image projected on the center of the mirror 2 is Adjustment is made so that light is received at the center of the conversion element 4. After performing this adjustment, the set screw 72 and the mounting screw 74 are firmly tightened, and the photoelectric substrate 7 is fixed to the lens block 6.

Next, referring to FIG.
After loosening the fixing screw 31 for attaching the lens 3 to
When the lens 3 is moved back and forth and the position is adjusted so that the image projected on the mirror is correctly formed on the photoelectric conversion element 4, the lens 3 is fixed to the lens block 6 with the fixing screw 31.
Tighten.

Finally, as shown in FIG.
After the stepped screw 52 is loosened, the reduction ratio adjustment knob 51 is operated with a finger to move the lens block 6 back and forth (±
X) Move slightly.

For example, when the image within the reference reading width W is not completely within the image forming plane of the photoelectric conversion element 4, the upper scale reduction knob 51 in FIG. The lens block 6 may be finely moved rearward by rotating the lower contraction ratio adjustment knob 51 clockwise while rotating the lens block 6 backward. Conversely, when the image is the photoelectric conversion element 4
In the case where an image is formed too small on the image forming surface, the upper and lower contraction ratio adjustment knobs 51 may be turned in the opposite directions to the above.

When the position of the photoelectric conversion element 4 is adjusted so that the reading width of the photoelectric conversion element 4 coincides with the reference reading width W of the mirror 2 in this manner, the setscrew 63 and the stepped screw 52 are firmly tightened to secure the optical base 5. Fixed to.

[0042]

As described above, according to the present invention, the lens block on which the lens and the photoelectric conversion element are mounted is slightly moved with respect to the surface to be read, and the contraction between the surface to be read and the photoelectric conversion element is performed. In order to perform the rate adjustment, a reduction movement transmission means for reducing the amount of movement and transmitting the movement to finely move the lens block is provided. Adjustment work can be performed, and stable reduction rate adjustment work can be realized at all times.
Variations in the accuracy of the read shrinkage ratio of each product can be suppressed, quality can be improved, and defective products due to poor shrinkage adjustment can be effectively prevented.

Further, according to the second aspect of the present invention,
A rack and pinion mechanism is used as the shrinking ratio adjusting means, and the shrinking ratio adjusting means can be constituted by approximately two parts, a rack portion and a pinion portion. This makes it possible to reduce the risk of failure and reduce manufacturing costs.

According to the third aspect of the present invention,
By operating the knob, the rack and pinion mechanism, which is the reduction movement transmission means, is operated to adjust the reduction ratio.Since fine adjustment of the reduction movement transmission means can be performed with a simple operation with a finger, manual operation is possible. The reduction ratio can be adjusted easily and quickly, and accurate reduction ratio adjustment can be easily realized.

Further, according to the invention described in claim 4,
A shrinkage adjustment knob that integrates the pinion and knob,
A screw to be inserted into the stepped through-hole provided on the shrinkage adjustment knob. The screw is loosened to perform the shrinkage adjustment work. After the completion of the shrinkage adjustment work, the screw is tightened to adjust the shrinkage. The knob and lens block are configured to be fixed, and by tightening the screw after the adjustment work, for example, a rattle occurs in the meshing state between the rack portion and the pinion portion, causing abnormal noise and vibration at the meshing portion. Since it can be prevented from occurring or loosening of the lens block, a highly reliable one can be provided.

Further, according to the fifth aspect of the present invention,
An elongated hole for guiding the movement operation by the reduction movement transmitting means is formed in the lens block, and a screw is provided for engaging with the elongated hole. When the lens block is finely moved by the rack and pinion mechanism, the elongated hole is formed in the elongated hole. The lens block is configured to be guided by the engaging screw, and the fine movement direction is guided by the screw engaging the long hole, so that a reliable and stable fine movement operation can be performed. Thus, a reliable and stable contraction rate adjustment operation can be performed.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an electronic blackboard device provided with an optical reading device according to the present invention according to the present invention.

FIG. 2 is a side view of the optical reading device.

FIG. 3 is an exploded perspective view thereof.

FIGS. 4A and 4B show a shrinkage ratio adjusting knob used for this, in which FIG. 4A is a perspective view and FIG.

FIG. 5 is a perspective view showing a scan line adjustment knob used for the same.

FIG. 6 is a cross-sectional view of a main part showing an attached state of the scan line adjustment knob.

FIG. 7 is an explanatory diagram showing the operation of the scan line adjustment knob.

FIG. 8 is an explanatory diagram showing the operation of the optical reading device.

FIG. 9 is a schematic perspective view showing a state in which an optical reading device is attached to a frame of a conventional electronic blackboard device.

[Explanation of symbols]

 Reference Signs List 1 light source 2 mirror 3 lens 31 fixing screw 4 photoelectric conversion element (CCD) 5 optical base 51 reduction ratio adjustment knob (reduction movement adjustment means) 51A pinion part (reduction movement adjustment means) 51B knob part (reduction movement adjustment means) 51C ( Stepped through hole 52 Stepped screw 6 Lens block 61 Mounting part 62 Long hole 63 Set screw 64 Rack part (reduction movement adjusting means) 65 (second) mounting part 65A Boss 65B Boss 7 Photoelectric substrate 71 Slotted hole 73 Scan Line adjustment knob 73B Knob 73C Cam 74 Mounting screw 8 Rack and pinion mechanism A Optical system B Optical adjustment means S Endless seat R1 Long diameter part R2 Short diameter part

Claims (5)

[Claims] 1. An optical reading apparatus comprising a light source, a lens, and a photoelectric conversion element for reading an image on a surface to be read, wherein a lens block on which the lens and the photoelectric conversion element are mounted is slightly moved with respect to the surface to be read. An optical reading device comprising: a reduction movement transmitting means for reducing and transmitting a moving amount and finely moving a lens block in order to adjust a reduction ratio between a read surface and a photoelectric conversion element. 2. The optical reading device according to claim 1, wherein a rack and pinion mechanism having a pinion portion and a rack portion meshing with the pinion portion is used as the reduction movement transmitting means. 3. A pinion portion of a rack and pinion mechanism is provided with a knob portion which is pinched by a finger, and the rack portion is moved by operating the knob portion to adjust a shrinkage ratio. Item 3. The optical reader according to Item 2. 4. A shrinkage ratio adjusting knob having a pinion portion and a knob portion integrated with each other, and a screw inserted into a stepped through hole provided in the shrinkage ratio adjusting knob, wherein the shrinkage ratio is adjusted with the screw loosened. 4. The optical reader according to claim 2, wherein the work is performed, and after the completion of the contraction adjustment operation, the screw is tightened to fix the contraction ratio adjustment knob and the lens block. 5. An elongated hole for guiding a movement operation by the reduction movement transmitting means is formed in the lens block, a screw is provided for engaging the elongated hole, and when the lens block is finely moved by the rack and pinion mechanism. The optical reading device according to any one of claims 1 to 4, wherein the lens block is configured to be guided by a screw that engages with the elongated hole.