JP2000321065A - Target for laser - Google Patents

Abstract

PROBLEM TO BE SOLVED: To locate a target accurately by enhancing visibility at the irradiating position of a laser beam on the target and preventing the profile of the laser beam from being blurred. SOLUTION: The laser target is produced by adding a fluorescent material to the transparent basic material of a target plate 10 being irradiated with a laser beam 3. When a laser beam is incident on the target plate, the fluorescent material absorbs and accumulates the laser beam to emit light. Since the basic material is transparent and has no directivity, the fluorescence can be visually confirmed easily even from the direction oblique to the optical axis of the laser beam. The fluorescence can be visually confirmed easily even in a bright place because attenuation thereof is suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser target having improved visibility so that the irradiation position of a laser beam from a laser irradiation apparatus can be easily confirmed even in a bright place.

[0002]

2. Description of the Related Art As an example of an apparatus using a laser target, there is a pipe laser apparatus.

[0003] The pipe laser apparatus forms a reference line for embedding a concrete pipe in soil by a laser beam.

When burying a concrete pipe, a groove is excavated, a laser irradiation device for irradiating a laser beam is installed at one of the pipe installation positions of the groove, and the laser beam is guided from the laser irradiation device between fixed straight lines. And lay a concrete pipe based on this laser beam,
The direction and inclination of the concrete pipe are adjusted so that the lower end of the inner surface coincides, and the groove is backfilled.

[0005] In positioning the pipe in such pipe burying work, the laser beam does not slack like a thread at any long distance and does not cut even if it is blocked by an obstacle. Is useful. There is a target for determining the irradiation direction and irradiation position of the laser beam and forming a laser beam reference line.

As shown in FIG. 2, the target includes a target plate 1 and a pair of left and right target tables 2 on which the target plate 1 is erected. The target plate 1 is for receiving a laser beam. When the laser beam 3 enters, the light is diffused, so that the position of the laser beam can be visually recognized from the incident side and the transmission side. That is, the laser beam 3 has directivity and is extremely difficult to visually recognize, but diffuses the light so that the worker can easily recognize the laser beam.

[0007] The laser beam 3 diffuses and transmits through the target plate 1, so that the worker can visually recognize the irradiation position of the laser beam 3 by diffusing and transmitting. For this reason, if the target plate 1 is a red laser beam so as to easily diffuse the laser beam 3,
It is the same color transparent red that easily transmits red. However, when the color is light, the amount of transmitted light is large and the amount of diffused light is small, so that it is difficult to visually recognize the light. And it is hard to see in a bright place. Furthermore, there is a problem that the spread of the diffused light is small only by coloring, and it becomes difficult to visually recognize the light in a situation where the light must be viewed from an oblique direction.

In order to increase the visibility in an oblique direction, there is a laser target shown in FIGS.

The structure of the target plate 5 of the laser target will be described with reference to FIG.

A large number of cylindrical lenses 8 are sandwiched between two transmission plates 6 and 7. The cylindrical lenses 8 are, for example, fiber sheets, and the cylindrical lenses 8 are in close contact with each other and have a horizontal axis. The cylindrical lens 8 has the function of expanding the incident laser beam 3 in one direction, and as shown in FIG.
The laser beam 3 transmitted through the target plate 5 is expanded in the vertical direction in the cylindrical lenses 8 closely contacted with each other horizontally, and the visibility from obliquely above is improved.

However, in order to diffuse the laser beam, the target plate 5 is colored in the same color as the laser beam, but when the density is low, the diffusion is small, and when the density is increased, the transmission decreases. Still have serious problems.

[0012]

As described above, the conventional laser target has a problem in diffusion when the laser beam passes through the target plate. When the color of the target plate is light, the amount of diffused light is small. When the color is dark, there is a problem that diffused light is difficult to transmit, and there is a problem that visibility in a bright place is lacking. As a means for increasing the amount of diffused light, the surface of the target plate may be made into a diffused surface such as a satin finish. However, due to the relationship with the amount of transmitted light, the outline of the laser beam is blurred, and the position specification becomes inaccurate. Therefore, the use of a diffusing surface is not a problem in applications that do not require accuracy, but is not suitable for applications in which it is necessary to accurately specify the position of a laser beam applied to a recent target plate. There was a problem.

In view of such circumstances, the present invention increases the visibility of the irradiation position of a laser beam on a target, increases the visibility of the outline of the laser beam, and specifies the position with high accuracy. Things.

[0014]

SUMMARY OF THE INVENTION The present invention relates to a laser target in which a base material of a target plate to be irradiated with a laser beam is transparent and a fluorescent material is added to the base material. The present invention relates to a laser target having a diffusion surface, wherein the fluorescent material is a laser target in which one or a plurality of fluorescent materials selected corresponding to a laser beam are blended.

When the laser beam is incident on the target plate,
The fluorescent material absorbs and accumulates the laser beam to emit light. Fluorescent light is emitted in all directions and has no directivity, so it can be easily viewed from an oblique direction with respect to the optical axis of the laser beam, and since the base material is transparent, there is little attenuation of the fluorescent light and it is easy to see in a bright place. is there.

[0016]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a vertical section of a target plate 10 of a laser target. As the supporting portion of the target plate 10, for example, those shown in FIGS. 2 and 3 can be used.

The base material of the target plate 10 itself is a transparent material such as an acrylic resin, and a fluorescent material is added to the acrylic base material.

The fluorescent color emitted from the fluorescent material emits fluorescence by absorbing the complementary color light. Therefore, the fluorescent material is selected according to the color of the laser beam used. Also, if necessary,
Two or more kinds of fluorescent materials are blended so that the fluorescent light can be emitted most effectively to the laser beam used.

Note that the fluorescent material absorbs and accumulates the energy of the irradiated light, and the accumulated energy is thermally released to emit light upon recombination. Agents, heavy metals), for example, calcium sulfide-bismuth, zinc sulfide-copper and the like.

The laser beam 3 incident on the target plate 10 from one side is not transmitted as it is but is absorbed by the fluorescent material and emitted again in a fluorescent color. Since the fluorescent light has no directivity and is emitted in four directions, it is diffused and emitted in a wide range of up, down, left, and right with respect to the transmission optical axis of the laser beam.

Since the base material of the target plate 10 is basically transparent, a large amount of emitted fluorescent light is emitted even in the transmission direction of the laser beam. The emitted fluorescent light allows the operator to collimate and confirm the irradiation position of the laser beam. Furthermore, when the incident surface of the laser beam is frosted, the contour of the laser beam spot is somewhat blurred, but the reflection on the target plate 10 is prevented, and the adverse effect of the reflected light on the observation device and the collimation device provided on the device side is reduced. You.

In general, the cross section of the laser beam irradiated to the target has a circular shape with a substantially uniform brightness. However, when a stop is provided on the optical axis, diffraction fringes are formed by a diffraction effect.
Therefore, when this diffraction fringe is used, the cross section of the light beam of the laser beam becomes a center portion and a ring shape concentric with the center portion. When the target plate 10 is irradiated with a laser beam having such a concentric ring-shaped light beam cross section, the mark indicating the center position drawn on the target plate 10 and the center of the laser beam are clearly shown since the outline of the laser beam is clearly shown. Can be performed more precisely and easily.

[0024]

As described above, according to the present invention, the base material of the target plate to be irradiated with the laser beam is made transparent, and a fluorescent material is added to the base material. High light transmission and diffusion rates are high,
It is easy to see from the entrance side and the transmission side even in a bright place, and the fluorescent light is emitted in a wide range, so it is easy to see from oblique directions, and a member such as a cylindrical lens for light diffusion is used. It is inexpensive because there is no need to provide it.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing an embodiment of the present invention.

FIG. 2 is a perspective view of a conventional laser target.

FIG. 3 is a perspective view of another conventional laser target.

FIG. 4 is a partially enlarged view of FIG. 3;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Target plate 2 Target stand 3 Laser beam 5 Target plate 10 Target plate

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Kenichiro Hara 75-1, Hasunumacho, Itabashi-ku, Tokyo Inside Topcon Corporation (72) Inventor Toshikazu Adagawa 75-1, Hasunumacho, Itabashi-ku, Tokyo Topcon Corporation (72) Inventor Hiroshi Wakatsuki 75-1 Hasunumacho, Itabashi-ku, Tokyo Inside Topcon Co., Ltd.

Claims (3)

[Claims] 1. A laser target, wherein a substrate of a target plate to be irradiated with a laser beam is made transparent, and a fluorescent material is added to the substrate. 2. The laser target according to claim 1, wherein a diffusion surface is formed on one surface of said target plate. 3. The laser target according to claim 1, wherein the fluorescent material is a mixture of one or more fluorescent materials selected corresponding to a laser beam.