JPH01114817A - Two-dimensional hologram scanner for co2 laser light - Google Patents

Abstract

PURPOSE:To exactly and at a high speed understand an object under an undesirable environment such as a fire, volcanic smoke, etc., by bringing CO2 laser light to one-dimensional scan by rotating at a high speed a zone plate having a hologram pattern for scanning CO2 laser liquid. CONSTITUTION:A zone plate 11 has a material whose penetrability for CO2 laser light 6 is high, for instance, a ZnSe substrate 4, and a hologram pattern 5 which has been formed by a material for reflecting the CO2 laser light, for instance, an Al thin film, and the hologram pattern 5 consists of four sectors 5-1, 502, 503 and 504 for deflecting the CO2 laser light so that a tilt and shift angle 12 becomes different and scanning width 13 becomes the same. The zone plate 11 rotates at a high speed by an encoder motor 3. When the zone plate 11 makes one rotation, the CO2 laser light 6 which has passed through the sector 5-1 brings scanning planes 9-2, 9-3 and 9-4 to one line scan and executes an interlaced scanning. Whenever the zone plate 11 makes one rotation, an angle of a reflection mirror 8 is changed successively by a galvanometer scanner 7 and the whole scanning plane 9 is scanned.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a two-dimensional hologram scanner for CO2 laser light, which is used for grasping objects in adverse environments including fire, volcanic smoke, and the like.

Conventional technology Under adverse environments including fire, volcanic smoke, etc., current monitoring TVs and the like cannot detect objects. On the other hand, CO2 laser light has excellent air propagation characteristics and can pass through smoke and the like.

Therefore, for monitoring objects at a fire scene or in a smoke plume, K
It has been considered to scan an object by using CO2 laser light and deflecting it two-dimensionally.

Normally, two-dimensional deflection methods for CO2 laser light include the X-axis,
A galvanometer scanner that rotates and deviates about the Y axis or a combination of a polygon mirror and a galvanometer scanner are used.

Problems to be Solved by the Invention However, with the method of deflecting the two axes of X and Y using a galvanometer scanner, as in the conventional example described above, it is difficult to perform accurate deflection, and it is difficult to arbitrarily select the deflection width. Interlaced scanning cannot be performed at high speed. On the other hand, a combination of a polygon mirror, a galvanometer, and a scanner allows high-speed scanning, but it is not possible to perform interlaced scanning, and in order to achieve accurate deflection, high-precision manufacturing of the polygon mirror and optical devices such as f-theta lenses are required. system is required, the structure is complicated, and it is not possible to create a compact and inexpensive scanner.

The present invention solves the problems of the above-mentioned conventional example, and
To provide a two-dimensional hologram scanner for CO2 laser light that accurately deflects two laser beams, enables arbitrary selection of the deflection width, performs high-speed interlaced scanning, is compact, and has a simple configuration.

Means for Solving the Problems The technical means of the present invention for solving the above problems is to form a thin film on one surface of the substrate using a material that reflects CO2 laser light. A zone plate having a scanning hologram pattern, a mechanism unit that rotates the zone plate at high speed, a mirror that reflects the CO2 laser beam reflected from the zone plate, and a galvanometer scanner that sequentially changes the angle of the mirror.
7iii.

Effect The effect of the above technical means is to perform one-dimensional scanning with the CO2 laser beam by rotating a zone plate having a hologram pattern for CO2 laser beam scanning at high speed, and to perform high-speed dimensional scanning that allows scanning width selection and interlaced scanning. Furthermore, by performing two-dimensional scanning using a reflecting mirror and a galvanometer scanner, it is possible to provide a compact and mechanically simple two-dimensional hologram scanner for CO2 laser light.

Embodiments Hereinafter, embodiments of the present invention will be described in detail based on the drawings. FIG. 1 shows a first embodiment of a two-dimensional hologram scanner for CO2 laser light according to the present invention. The CO2 laser beam 6 emitted from the CO2v-laser oscillator 1 is incident on the lower surface of the zone plate 11 by the reflecting mirror 2. Zone play) 11 is made of a material that is highly transparent to the CO2 laser beam 6, such as the Zn8e substrate 4, and a material that reflects the CO2 laser beam.
For example, the hologram pattern 5 has a hologram pattern 5 formed of an A2 thin film, and the hologram pattern 5 includes four sectors 5-1, 5-2, . It consists of 5-3.5-4. The zone plate 11 is rotated at high speed by the encoder motor 3. The CO2 laser t6H is deflected by the hologram pattern 5 of the zone plate 11, and the scanning plane 9 is scanned by the reflection mirror 8 attached to the galvanometer scanner 7.
The top is scanned as the zone plate 11 rotates.

When the zone plate 11 rotates once, the CO2 laser beam 6 that has passed through the sector 5-1 scans the scanning plane 9-1 for one line, and the CO2 that has passed through the sector 5-2.5-3.5-4 in the same way. The laser beam 6 is directed to the scanning plane 9-2.9-3.9-
4 is scanned one line and interlaced scanning is performed. The galvanometer scanner 7 rotates every time the zone plate 11 rotates once.
The entire scanning plane 9 is scanned by sequentially changing the angle of the reflecting mirror 80. The Zn8e substrate 4 can also be made of KCQ, germanium or other materials that are highly transparent to CO2 laser light.

FIG. 2 shows another embodiment of the two-dimensional hologram scanner for CO2 laser according to the present invention. A CO2 laser beam 6 is reflected by a reflecting mirror 2 onto a zone plate 11 on which a hologram pattern 5 is formed on a substrate IO made of a material with low transmittance for CO2 laser beams.
The reflected light is directly incident on the hologram pattern 5 without being transmitted, and the reflected light is guided to the reflection mirror 8 to collect CO by the hologram.
This is a two-dimensional hologram scanner that performs one-dimensional scanning using reflected light from two laser beams. The other parts are the same as the configuration shown in FIG. 1, so their explanation will be omitted.

Effects of the Invention As described above, the present invention enables scanning width selection,
By performing high-speed dimensional scanning capable of interlaced scanning and performing two-dimensional scanning using a reflecting mirror and a galvanometer scanner, it is possible to provide a compact, mechanically simple, and inexpensive two-dimensional hologram scanner for CO2 laser light. Objects can be grasped accurately and at high speed in adverse environments such as volcanic smoke.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing one embodiment of a two-dimensional hologram scanner for CO2 laser light according to the present invention, and FIG. 2 is a main part showing another embodiment of the two-dimensional hologram scanner for CO2 laser light according to the present invention. FIG. 1... CO2 laser oscillator, 2... Reflection mirror, 3
...Encoder motor, 4...Zn5e board, 5.
... Hologram pattern, 5-1.5-2.5-3.5
-4...Sector of hologram pattern, 6...CO
2 laser beam, 7... galvanometer scanner, 8...
- Reflection mirror, 9...Scanning plane, 11...Zone plate, 12...Tilt angle, 13...Scanning width. Patent applicant: Director of the Agency of Industrial Science and Technology Kozo Iizuka Figure 2

Claims (1)

[Claims] A zone plate having a CO_2 laser beam scanning hologram pattern formed of a thin film of a material that reflects the CO_2 laser beam on one surface of the substrate, a means for rotating the zone plate at high speed, and a means for one-dimensional scanning by the hologram pattern. A two-dimensional hologram scanner for CO_2 laser light, characterized by comprising a reflection mirror that reflects the CO_2 laser light and a galvanometer scanner that changes the angle of the reflection mirror.