JPS58132213A - Optical scanning detector - Google Patents

Abstract

PURPOSE:To obtain an optical scanning detector which improves the detection precision with a relatively simple constitution, by providing a pair of optical scanning systems which are provided with a pair of specular faces, which face each other and are arranged in parallel, and are rotated synchronously with each other. CONSTITUTION:A laser light 22a emitted from a light source 21 is incident vertically to an object 31 to be examined through optical scanning systems 23a and 23b. A transmitted light 22c becomes a light 22g through optical scanning systems 26a and 26b and is incident to a photodetector 34. When discs 24 and 27 are rotated synchronously, an optical scanning system 23 is rotated around the mirror body 26b of a scanning system 26, and the light 22c scans the surface of the object 31 to be examined in a form of an arc, and the direction of the pattern of the object 31 included in the light 22g is not broken by the rotating operation. When the object 31 to be examined is moved in the direction orthogonal to the light 22c, scanning is performed stably, and the precision of examination is improved.

Description

[Detailed Description of the Invention] [Technical Field to Which the Invention Pertains] This invention relates to a shadow light scanning detection device for textiles and color cathode ray tubes.The information processing technology described above is applicable to two-dimensional patterns, so it essentially requires a large amount of data. Possibility of processing information at high speed
4. However, in order to construct a large-volume data processing system utilizing this high speed, tζ must prepare a system for inputting large amounts of data into the optical processing system at high speed.

There are generally two types of such input systems: one in which the input cover itself moves, and one in which the optical processing system moves. In a system in which the input cover turn itself moves, there are many methods such as relative positioning of the input cover turn to the data processing system, single rotation direction alignment, optical axis direction alignment, etc., while systems in which the optical processing system itself moves generally perform optical scanning. Also called a conventional galvano mirror set.

Many methods have been announced, including the ultrasonic type and the vibrating mirror type.
There have been few optical information processing rings Cζ suitable for irradiating the subject with a uniform amount of light and perpendicularly. FIG. 1 shows an example of a conventional scanning detection device having this purpose. In the figure, 1 is a light source that generates coherent light (e.g. laser light), and this light m
A laser beam 2 emitted from a laser beam 2 enters an optical deflector 3. The optical deflector 3 is disposed at the focal point of the scanning lens 4, and the beam 5 deflected by the optical deflector 3 is turned into a beam 6 parallel to the optical axis by the scanning lens 4. It is possible to process a two-dimensional pattern by inputting the light into the image.

In such an optical system, not only is a large scanning lens 4 required to scan the surface of the object to be examined over a large distance, but also making the scanning speed uniform over the object 7 requires consideration of the characteristics of the deflector 3 and lens aberrations. This was extremely difficult due to the influence of So something like this.

Devices that have overcome technical difficulties have had the disadvantage of being complex and expensive.

[Purpose of the invention]

This invention was developed to solve the above-mentioned problems, and has a relatively simple configuration that allows for easy vertical scanning of the object, as well as uniform scanning over the entire surface of the object, resulting in accurate detection. An object of the present invention is to provide an optical scanning detection device that can significantly improve the performance.

[Summary of the invention]

This invention includes a light source that generates coherent light, a pair of mirror bodies that are arranged opposite to each other so that their reflecting surfaces are parallel, and is arranged opposite to the first optical scanning system. , comprising a second optical scanning system that is rotationally driven in synchronization with the first optical scanning system around the position of the mirror body on the side that emits light;
The light from the light source is guided through the eighteenth and second optical scanning systems, and the pattern of the subject placed between these optical scanning systems is extracted.

〔Effect of the invention〕

According to this invention, a roller is provided with a pair of mirror bodies disposed opposite to each other so that one reflecting surface is parallel to each other, and uses first and second optical scanning systems that are rotationally driven in synchronization with each other. Since scanning is always performed perpendicularly and uniformly to the subject, pattern detection accuracy can be improved.

In addition, there is no need to use a particularly wide-diameter lens, as is the case with conventional devices, and there is no need for special control over the deflector for uniform scanning.

The device can be constructed relatively easily and therefore costs can be reduced.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. In FIG. 2, 21 is a light source that emits coherent light, such as a laser device. A first optical scanning system includes a pair of mirror bodies 23a and 23b facing each other so that one reflective surface is parallel to the optical path of the laser beam 22m emitted from the laser device 21, tilted at approximately 45 degrees. 23 will be provided. This scanning system 23 is constructed by fixing a body 23m on the input side at the center position of a disk 24, fixing a mirror body 23b around it, and pressing a drive disk 251m of a rotary drive device 25 onto the surface of the disk 24. The configuration is such that one optical scanning system 23 is rotated.

A second optical scanning system 26 is provided opposite to the first optical scanning system 23, in which a pair of mirror bodies 26m and 26b are tilted at 45 degrees so that their reflective surfaces are parallel to each other, as described above.

The second optical scanning system 26 has a mirror body 26b on the side that emits light fixed at the center position of the disk 27, a mirror body 26m fixed at the periphery of the disk 27, and a rotation drive device attached to the circumferential surface of the disk 27. 2
The configuration is such that the second optical scanning system 26 is rotated by pressing the driving disk 28m of No. 8 into contact with each other. In this case, the rotation of the second optical scanning system 26 is synchronized with the rotation of the first optical scanning system 23. Mirror body 23b on the output side of the first optical scanning system 23 and the second optical scanning system 2
6 yen II corresponding to the mirror body 26b on the output side of 6
! A through hole 29.30 is formed in 24.27, and the mirror bodies 23b and 261 are placed opposite each other. Then, a subject 31 is interposed between the first optical scanning system 23 and the second optical scanning system 26, and the subject 31 is perpendicular to the light beam 22C on the output side of the first optical scanning system 23. A drive mechanism 32 is provided to move the object at a constant speed in the direction of the object. Further, on the output side of the second optical scanning system 26, a half mirror 33 and a photodetector 34 are provided corresponding to the mirror body 26b. In addition, 2
2a to 22h indicate laser beams at those positions.

Next, the operation of this optical scanning detection device will be explained.

A laser beam 22 emitted from a light source 21 is directed perpendicularly to the subject 31 via a first optical scanning system 23 as shown in the figure.
After being irradiated and transmitted through the subject 31, the light is sent to the photodetector 341 via the second optical scanning system 26.

First, the operation of the first optical scanning system 23 will be explained with reference to the simplified diagram of FIG.

The laser beam 22m is reflected by the mirror body 23a to become 22b, and then reflected by the mirror body 23b to become 22c. Since the mirror bodies 23 and 23b are provided facing each other so that their reflective surfaces are parallel, the laser beam 22m and the laser beam 22
c is always vectorially equal. Furthermore, it should be noted that the small arrows drawn perpendicular to the laser beam in each part of Figure 1 may be a three-dimensional coordinate system in the cross section of the beam, and the two It can be said that the coordinate system of the incident laser beam 221 and the coordinate system of the emitted laser beam 22c are always equal to each other. That is, the condition of the incident laser beam 22m is accurately reflected in the condition of the emitted laser beam 22C.

The laser beam 22C passes through the subject 31, and after the same process is repeated in the optical scanning system 26 of S2, it is emitted as a laser beam 22g.

That is, the laser beam 22M is transmitted through four mirror bodies 23a e
After being sequentially reflected by 23b2s ae 26b, it becomes a laser beam 22g which is vector-wise identical to this.

Therefore, the pattern on the object 31 inserted in the direction transverse to the laser beam is transferred or corrected while maintaining its direction to the laser beam 22g.

Next, when the disks 24 and 27 are rotated synchronously in this device, they rotate around the mirror body 23a of the first optical scanning system 23 and the mirror body 26b of the second optical scanning system 26, and the light beam 2
2c is scanned over the subject 31 in an arc shape. At this time,
The direction of the pattern of the object 31 included in the laser beam 22g is not broken even by the rotational operation and is kept the same.

Therefore, according to such a configuration, the laser beam a22
Since the beam c always enters the subject 31 in the perpendicular direction, it is possible to scan a subject 31 of any size by adjusting the radius of one rotation. Further, the scanning speed at this time can be easily kept constant.

Further, in a direction orthogonal to the laser beam 122C, the object 3
By moving 1, it is possible to stably scan the entire surface of the object 31 while maintaining a state perpendicular to the surface.
Inspection accuracy can be significantly improved compared to conventional methods.

8. When such an optical scanning detection device performs optical scanning, the amount of light may vary. The reason for this is that when polarized light is incident on a system with many reflective surfaces, the reflectance of the mirror differs depending on the direction of polarization, causing variations in the amount of light output depending on the rotation angle. In such a case, scanning with a uniform light amount can be performed by controlling the light amount gap of the feature extraction laser beam 22h detected by the half mirror 33ζ by using the full amount of the laser beam 22g.

As described above, the optical scanning detection device of the present invention can stably scan a large area of the object to be inspected, so it is very effective in detecting defects in fabrics within 1%, defects in cathode ray tube shadow masks, etc. .

[Other embodiments of the invention]

It should be noted that the present invention is not limited to the above-mentioned embodiments, and can be implemented with various modifications within the scope of the gist.

For example, in the above embodiment, the mirror on the output side of the first optical scanning system and the mirror on the input side of the second optical scanning system are fixed on a disk, but this invention is not limited to IC. By making these integral parts movable and freely changing the radius of rotation of the scanning beam, it is possible to easily scan a subject of any size.

Further, in the above embodiment, the first mirror bodies constituting the first optical scanning system and the second optical scanning system are inclined at 450 degrees and disposed in parallel, but this invention is limited to 450 degrees. 2 is a schematic configuration diagram showing an embodiment of the present invention, and FIG.
The figure is an explanatory diagram of the operation of the same embodiment.

1... Light source z... Laser beam 3...
Optical deflector 4... Scanning lens 5... Deflected light ray 6... Parallel light ray 7... Subject
8... Diffracted light 9... Converging lens 10...
- Photoelectric converter 21...Laser device 22a-22
h... Laser beam 23... Optical scanning system 23a, 23b, 26a, 26b of t41 --- Mirror body 2
6... Second optical scanning system 24.27... Disc 25
．． 28... Rotation drive device 25a = 28a...-
Drive disk 29.30...Through hole 31...
Subject 32... Drive mechanism 33... Half mirror 34... Photodetector Fig. 2 Fig. 3

Claims (3)

[Claims] (1) A light source that generates coherent light and a pair of mirrors placed opposite each other so that the reflective surfaces are parallel, and the center is located at the position of the mirror on the side where the light from the light source enters. The first optical scanning system includes a rotationally driven first optical scanning system and a pair of mirror bodies arranged opposite to each other so that the five reflecting surfaces are parallel to each other.
a second optical scanning system disposed opposite to the optical scanning system Cζ and rotationally driven in synchronization with the first optical scanning system about the position of the mirror body on the light emitting side; The subject placed between the first edict and the second optical scanning system, and the! ! X2
1. An optical scanning detection device comprising: a photodetector for detecting the output of an optical scanning system. (2) The optical scanning detection device according to claim 1, characterized in that the subject is moved in a direction perpendicular to the light passing therethrough. (3) Pre-scanning according to claim 1 or 2, wherein a part of the output of the second optical scanning system is used to correct light amount fluctuations accompanying rotational scanning. Line payment device.