JPH0548451B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Technical Field> The present invention relates to a device that diffuses light from one laser light source over a wide angle in a predetermined direction to obtain one or more projected light beams.

<Prior art> Conventionally, when attempting to obtain a single beam of light from a single laser light source, a device was used that rotated a polygonal mirror at high speed to scan the reflected light in a predetermined direction at high speed. However, not only did this require a complicated configuration due to the high-speed rotation of the mirror, but it also had the disadvantage that it could not be applied to electronic devices that transmit information at high speeds because it only had a running light spot. Furthermore, devices have been proposed in the past that diffuse a laser beam by a minute angle by refracting it with a cylindrical lens, but these devices cannot be applied when it is desired to obtain diffused light at a wide angle.

<Industrial Application Fields> The present invention can be used in marking devices for surveying equipment, architecture, bridges, shipbuilding, etc. when obtaining long horizontal or vertical light beams of several meters to several tens of meters. When emitted into the atmosphere, it can be used as a laser, and small ones can be used for line illumination in laser printers, facsimile machines, copiers, etc. Furthermore, it can be used to branch one transmission line into multiple transmission lines in optical communications. In addition, it can be used in a wide range of application fields of laser light, such as material processing, advertising, art, and other displays.

<Object of the invention> The main object of the invention is to constantly obtain a wide-angle fan-shaped diffused light beam from a single laser light source, thereby projecting a straight, flicker-free and focused light beam onto the irradiated object. The purpose of this project is to provide a device for projecting images. Another object of the present invention is to provide a device that constantly projects a T-shaped light beam consisting of a horizontal line and a vertical line from a single laser light source.

<Principle of the Invention> FIG. 1 shows a diagram of the principle of the invention, and FIG. 2 shows an explanatory diagram of its operation.

The red visible light output of the He--Ne laser tube 1 is diffused by a predetermined angle θ by a concave lens 2, and this diffused laser beam is focused by a convex lens 3 and focused on a projecting object (not shown). A reflector 6 is arranged in front of the convex lens 3. This reflector 6 has a cylindrical reflecting surface 5 whose reflection angle changes continuously.
, and in the case shown, the axis of the cylindrical surface is perpendicular to the plane of the paper.

Now, if the leftmost light 41 of the laser beam 4 is reflected at point A, and the angle at point A of the reflecting surface 5 is α ₁ , then this light 41 is reflected by β ₁ = 2α ₁ and becomes reflected light 41A, Further, the rightmost light 42 is reflected at point B, and if the angle of the reflecting surface at point B is α ₂ , this light 42 is reflected by β ₂ =2α ₂ to become reflected light 42B. The laser beam 4 is diffusely reflected at a wide angle in the range from the reflection angle β ₁ to the reflection angle β ₂ and becomes a fan-shaped diffused beam 7 .

<Configuration of the Invention> The configuration of an apparatus for obtaining a projected light beam using a laser beam according to the present invention will be described with reference to FIG.

The present invention comprises a laser beam generation source 1, a concave lens 2 that diffuses the laser beam into a laser beam having a predetermined diameter, and a convex lens 3 that focuses the laser beam diffused by the concave lens 2 onto a projecting object. ,
The reflector 10 has a reflector 10 disposed in front of the convex lens 3, and the reflector 10 is bilaterally symmetrical with a plane of symmetry including the center of the laser beam, and the reflector 10 is located at a position closest to the convex lens 3. Between the ridge line 14 and the farthest end portions 15A and 15B, a reflection angle is set in such a direction that the reflection angle of light passing further away is gradually smaller than the reflection angle of light passing near the ridge line 14. forms cylindrical reflection curved surfaces 11A, 11B in which a line perpendicular to the center line of the laser beam on the plane of symmetry is parallel to the generatrix of the reflection curved surface, and the end portions 15A, The width W of the reflector 15B is less than or equal to the diameter d of the laser beam passing through the reflector 10, and it is configured to obtain one straight light beam from one laser light source.

<Example> Fig. 3 shows a plan view of the main parts of an example of the present invention,
FIG. 4 shows an explanatory diagram of its operation.

The laser beam 4 incident on the reflector 10 is
As shown in the figure, the output light of the He--Ne laser tube is diffused by a concave lens 2, and then slightly focused by a convex focusing lens 3, and the diameter of the laser beam 4 is several millimeters to more than ten millimeters.

Focus adjustment of the projected light beam is normally performed by displacing the convex lens 3, but in the present invention, in order to maintain stable accuracy of the projected light beam, the convex lens 3 and the reflector 10 are adjusted.
is fixed on a base (not shown), and the concave lens 2 is configured to be freely adjustable in the front and rear directions.

The reflector 10 is bilaterally symmetrical with a plane passing through the center 43 of the laser beam 4 (a plane perpendicular to the plane of the paper in FIG. 3) as a plane of symmetry, and has both cylindrical reflections at the position closest to the convex lens (at the rearmost end). Side 1
A ridgeline 14 is formed where 1A and 11B intersect, and the distance between both reflective surfaces increases monotonically from the ridgeline 14 to the frontmost ends 15A and 15B. W is formed to be equal to or slightly smaller than the diameter d of the laser beam 4. In other words, ridge 1
The angle of reflection of the light passing near 4 is the largest, and the angle of reflection of the light changes continuously in the direction of becoming smaller as the distance from the plane of symmetry increases. It is manufactured and adjusted so that it travels straight in the vicinity of 15B without being reflected by it.

As a result, as shown in FIG. 4, one straight and clear light projection line 18 can be obtained on the light projection object. According to experiments, when a horizontal line with a length of 50 m is projected at a distance of 25 m in front of the reflector 10, the line width is 2.5
mm, line width variation was less than 5%, and straightness was 1/300,000.

FIG. 5 shows a side view of the main parts of another embodiment of the present invention, and FIG. 6 shows an explanatory view of its operation. This embodiment differs from the previous embodiment in that the reflector 1
0A is a symmetrical cylindrical reflection curved surface 11
In addition to A and 11B, a third cylindrical reflection curved surface 11C whose reflection angle changes continuously only in the direction perpendicular thereto is integrally formed.
To explain this in more detail, the ridgeline 14 where the symmetrical cylindrical reflection curved surfaces 11A and 11B intersect is installed at a position passing through the center 43 of the laser beam 4, as in FIG. Only the light from the lower half is received, and the light above that is reflected obliquely upward by the third reflective curved surface 11C. The bottom surface 12 of the reflector 10A is the substrate 13
It is fixed with a bolt 16.

As a result, as shown in FIG. 6, a T-shaped light projection line consisting of one horizontal line 18 extending left and right and a vertical line 19 perpendicular to the horizontal line 18 can be obtained.

<Effects of the Invention> According to the present invention, a straight light beam extending over several tens of meters in length can be constantly obtained from one laser light source without using any moving mechanism. Therefore, it is particularly effective as a device for obtaining marking lines at construction sites.

In addition, the reflection angle of the high-intensity part at the center of the laser beam is large, so that it is focused far away at both ends of the left and right projection lines, and the reflection angle of the low-intensity part of the left and right peripheral parts of the laser beam is small, so that the left and right projection lines are focused. Since the beam is focused relatively close to the center of the beam, the brightness of the long beam of light is almost equalized.

Furthermore, since the width W of the end of the reflector is less than or equal to the diameter d of the laser beam, the light that is not reflected by the reflector travels straight and a focused point is obtained directly in front of the reflector.

[Brief explanation of drawings]

Fig. 1 is a diagram of the principle of the present invention, Fig. 2 is an explanatory diagram of the operation of the present invention, Fig. 3 is a plan view showing the main part of an embodiment of the invention, Fig. 4 is an explanatory diagram of the operation of the embodiment, Fifth
The figure is a side view showing the main parts of another embodiment of the present invention, and FIG. 6 is an explanatory diagram of the operation of the embodiment. 1... Laser light generator, 2... Concave lens, 3...
...Condensing convex lens, 4...Laser beam with a predetermined spread, 10, 10A...Reflector, 11A...
...Left cylindrical reflection curved surface, 11B...Right cylindrical reflection curved surface, 11C...Top cylindrical reflection curved surface, 14...Ridge, 15A, 15B
...front end of left and right cylindrical reflection curved surface, 18,
19...Light ray on the projecting object.

Claims (1)

[Claims] 1. A laser light generation source 1, a concave lens 2 that diffuses the laser light into a laser beam having a predetermined diameter,
It has a convex lens 3 that focuses the laser beam diffused by the concave lens 2 onto the projecting object, and a reflector 10 disposed in front of the convex lens 3, and the reflector 10 is located at the center of the laser beam. The angle of reflection of light passing near the ridge line 14 is between the ridge line 14 closest to the convex lens 3 and the ends 15A and 15B farthest from the convex lens 3. The reflection angle continuously changes in a direction in which the reflection angle of light that passes further away becomes gradually smaller, and the line perpendicular to the center line of the laser beam on the symmetry plane and the generating line of the reflection curved surface are Parallel cylindrical reflection curved surface 11A,
11B, and the ends 15A, 15B.
A device for obtaining a projected light beam using a laser beam, the width W of which is less than the diameter d of the laser beam passing through the reflector 10, and configured to obtain one straight projected light beam from one laser light source. 2 Fixing the convex lens 3 and the reflector 10,
3. A device for obtaining a projected light beam using a laser beam according to claim 2, wherein the concave lens for diffusing the laser beam is adjustable to adjust the focus on the projecting object. 3 The reflector has cylindrical reflection curved surfaces 11A and 11B that are symmetrical with respect to the center of the laser beam.
and a cylindrical reflection curved surface 11C having an axis orthogonal to the axes of both cylindrical reflection curved surfaces, so as to obtain a T-shaped projection line consisting of one straight projection ray and a projection ray orthogonal to it from one laser beam. An apparatus for obtaining a projected light beam using a laser beam according to claim 1, which is constructed.