JPS6263804A - Linear light projecting device - Google Patents

Abstract

PURPOSE:To project a linear beam of light to an optional space by providing plural light sources for radiating plural linear beams of light which converge to one point on a plane and have width in the direction vertical to the plane, and a rotary plane mirror whose shaft vertical to the plane is a revolving shaft at the convergent point, on one plane. CONSTITUTION:On a periphery C centering around a shaft 4 on a plane vertical to a revolving shaft 4 of a rotary plane mirror 3, plural pieces of light source bodies 1 which have combined a semiconductor laser and a columnar lens are placed at an equal interval. In this state, a band-shaped linear light 2 having a prescribed length is radiated in the direction vertical to the plane containing the periphery C, toward the shaft 4 from light source body 1. Next, the linear light 2 is projected onto an object to be measured 5 by controlling the mirror 3 by a galvanomotor. The light source body 1 is flickered in accordance with a code generated by an electronic circuit, inputs an image from a TV camera 6 and calculates a distance of a point on the object 5 to be measured, and measures a shape of the object 5.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a device that simultaneously scans and projects a plurality of linear lights toward a directed space.

[Conventional technology]

Conventionally, the following two methods have been used to project encoded grids.
There were different methods. The first method is to prepare encoded grid patterns on a plurality of slide films in advance, and project them onto the surface of an object using a single slide projector while exchanging them. (M, M
1nou, T, Kanadeancl T
, Sakai: “A Method o
f Time-CodedP arallel
P 1anes of Light for D e
pth Mea-suresient”, Tran
, I E CE of Japan, E64°N
o, 8. pp521-528).

The second method uses an optical shutter element (for example, (P b , L a ) (Z'r , T i )0
The method of projecting a coded lattice using irregular circles to project the light pattern on transparent porcelain (Ueda, Matsumoto: ``It also overcomes the drawbacks of low time-series marking accuracy and deviations in projection points.

On the other hand, in the system using the optical shutter element, it is possible to flash the striped light on the tile, and there is no positional shift.

However, this method requires a voltage of several hundred volts to drive the optical shutter element, which increases the size of the power supply circuit.

As for the light source, as shown in Fig. 5, in either method, the light emitted from a single light source 7 is transmitted through a through hole 8a of a shielding plate 8 such as a slide or a light shutter element, and is called linear light 2. Therefore, most of the luminous flux emitted by the light source 7 is inevitably wasted, and only a small portion is projected as the linear light 2.

Therefore, in order to make the intensity of the projected linear light 2 sufficiently large, the light source 7 must be unnecessarily strong (for example, I
As a result, a large-capacity power supply to drive the light source 7 and a large-capacity power supply to cool the heat generated from wasted power must be prepared. A powerful cooling device is required, which increases the size of the entire device. In addition, since an incoherent light source was used as the conventional light source 7, it was not possible to obtain the linear light 2 with a sufficiently thin thickness t in a sufficiently wide space. This may cause problems in measurements, etc. using it. As the thickness of the linear light 2 increases, the accuracy of the position of the point on the object to which the distance data obtained as a result of calculation corresponds becomes worse, and the brightness decreases due to the increase in the irradiation area ζζ. /N ratio deteriorates. However, the used coherent light source Q-4F had problems such as being unsuitable for the reason that it is a high output light source as mentioned above.

Regarding the scanning method, in the conventional method when the linear light 2 is 1F-1, the linear light 2 is scanned by a rotating plane mirror, but when projecting a plurality of linear lights 2, conventionally Instead of scanning, a grid for the entire measurement space was created on the slide, or a high-density optical shutter element (for example, 100 to 256 elements) was used to obtain the spatial resolution corresponding to the number of shutter elements. Therefore, the spatial resolution of the device depends on hardware such as slide films and optical shutter elements, and flexibility is lacking.

This invention was made in order to solve the above-mentioned problems, and its purpose is to provide a linear light projection device that can obtain sufficient light output and can freely configure scanning configurations as needed using software. do.

[Means for solving problems]

A linear light projection device according to the present invention includes a plurality of light sources that emit linear light in a plane perpendicular to the plane toward one point within the plane, and a plurality of light sources placed at the one point. The device includes a rotating plane mirror whose rotating shaft is perpendicular to the plane, and means for identifying each linear light beam.

[Effect]

In this invention, the linear lights emitted from a plurality of light sources are reflected by a rotating plane mirror and radiated in an arbitrary direction, and are classified into m by the identification means.

〔Example〕

First, the principle of the invention is shown in FIG. IA, 1B.

1C,... are each independently parallel to the paper surface 2A
! A light source that emits -281 and 2C1, both of which are arranged on the paper, and a linear light of 2A! .

2Bt and 2c1 are both indicated by a single line, but this indicates that they are thin, and the paper and A, IB,
The IC emits a linear light 2A toward a point P on the axis of rotation 4.
Emit +-2B i-2CI. As a result, all the linear lights 2A1, 2B1, 2ct are converged and reflected at one point P on the rotation axis 4 of the rotating plane mirror 3.1. As if a plurality of linear lights 2 A + - 2 B t-
2Ct light source IA, 1N3. It is projected that an IC exists. Furthermore, when the rotating plane mirror 3 is rotated, each of the linear lights 2AI, 28, and 2C1 are projected with directionality in a direction according to the rotation angle of the rotating plane mirror 3. In FIG. 1, the linear light 2A1 from the light source 1A passes through the rotation axis 4 to the linear light 2A2, and similarly from 1B to 282, and from 1C to 2Cg.
It shows that it is projected to.

FIG. 2 shows an embodiment of the present invention, in which the present invention is applied to a device for measuring the shape of an object at high speed. Its operating principle is shown below.

First, light sources 1 (light sources IA, IB) of linear light 2 are arranged on a circumference C centered on the rotation axis 4 of the rotating plane mirror 3.

A general term for IC, etc., where each light source is a combination of a semiconductor laser and a cylindrical lens) are arranged at equal intervals, and a rotating plane mirror 3 is controlled by a galvano motor to emit a linear light onto the object to be measured 5. Project 2. At this time, the arrangement of the optical system is light #I
The intervals between A, IB, IC, . . . are increased to reduce the angle of rotation of the rotating plane mirror 3 once. A light source 1 using a semiconductor laser blinks according to a code generated by an electronic circuit. Input images from a TV camera 6 as an identification means for each code at each angle,
The distance of a point on the object to be measured 5 is calculated from the position of the NI line in the image according to the principle of triangular IWI amount (Japanese Patent Publication No. 50-3
(See Publication No. 6374). Thereafter, the shape of the object to be measured 5 is measured based on the obtained distance data.

The purpose of using a plurality of linear lights 2 is to shorten the measurement time, and the bright lines in the image and the light source 1 (M, Mino
u, T, Kanade and T, 5akai
: ”AMethod of Time-Co
ded Parallel P 1anes o
f Light for Depth Mes
urement”, T ran, I ECE
of Japan, E84) No.

8. 2pp521-528).

FIG. 3 shows another embodiment of the invention, which is almost the same as the embodiment shown in FIG. 2, but in this embodiment, the light sources IA, IB, iC, . . . The rotation angle of the rotating plane mirror 3 is increased by placing it nearby. Second
In the illustrated embodiment, the size of the entire space in which the linear light 2 is projected is the light sources 1A, IB, IC, etc. arranged at both ends.
It is fixed by the angle formed by the semiconductor laser, but the fineness of measurement can be freely set by reducing the rotation angle.

On the other hand, in the embodiment shown in FIG.
Although it is fixed by the angles formed by A, IB, IC, . In this way, when comparing the two, both have advantages and disadvantages, and can be used depending on the object to be measured.

FIG. 4 is an explanatory diagram showing the range of incident angles of the rotating plane mirror 3.
The horizontal length of the rotating plane mirror 3 is w, 4j3 beams 2,
Furthermore, since the thickness t of the linear light 2 is very small (within several millimeters), the range of the incident angle θ is wide. In addition, if the linear light 2 does not converge on the rotation axis 4, the upper light source 1 will apparently move as the rotating plane mirror 3 rotates, which complicates the calculation of the light source 1 required for processing the measurement results. When the linear light 2 converges on the rotation axis 4, just change the direction onto the rotation axis 4.The linear light 2 will be emitted just as there is a light source 1 of the linear light 2, so the image will be It becomes easy to calculate the distance information on the surface of the object to be measured 5 using the position of the linear light 2.

Note that for the light sources IA, IB, IC, etc., a Ha-Ne laser or the like may be used in addition to a semiconductor laser. Further, depending on the purpose, the light from the lamp may be passed through a slit and then imaged by a lens to form the linear light 2.

Furthermore, as a means for identifying the plurality of linear lights 2, the light source IA
, IN3. Make IC, -...- blink in chronological order, etc.
You can differentiate them by coloring the slits, changing the slit width, changing the oscillation wavelength of the light, or using a combination of these.

〔Effect of the invention〕

As explained above, the present invention provides a plurality of light sources that emit linear light in a plane perpendicular to the plane toward one point within the plane, and directs each of the linear lights to the one point. The mirror is configured such that the rotation axis is perpendicular to the plane and reflects the light by a rotating plane mirror, simultaneously projecting a plurality of gratings in any direction, and identifying them with the identification means.
Rather than masking and projecting the light output from each light source as in the conventional method, there is less power loss and it is possible to use low-output light sources that could not be used in the past. By using this invention, for example, sufficient optical output can be obtained with a semiconductor laser of approximately 5 mW for one linear light source (as described in the above-mentioned Journal of the Institute of Electronics and Communication Engineers, "Time-series coded grating method"). ``In the deviceization'', an IKW projector is used as a 100-line light source.)It relies on semiconductor hardware as a light source and lacks flexibility, but in this invention, scanning is performed using a rotating plane mirror. For,
You can freely set the scanning configuration according to your needs using software. In addition, simply reflecting the light with a rotating plane mirror is solved by using a rotating plane mirror.

Focusing on the encoding of the striated light, the projection direction of the striated light is independent of the selected code, so the positional shift of the striated light as in the case of a method using a slide can be avoided. do not have. Mat=, light source blinking t! Since different encoding grids can be obtained depending on the number of steps, much faster operation is possible compared to methods using slides.

Therefore, the present invention is extremely useful in devices that measure the shape of objects at high speed and in a non-contact manner, as well as devices that have an optical system that projects C-line light toward a specific space.

[Brief explanation of drawings]

Fig. 1 is a diagram showing the principle of this invention, Fig. 2 is a block diagram showing one embodiment of this invention, Fig. 3 is a block diagram showing another embodiment of this invention, and Fig. 4 is a rotating plane mirror. FIG. 5 is a diagram showing the principle of the conventional linear light projection method. In the figure, 1 is a light source, IA, IB, and IC are light sources, 2 is a linear light, 3 is a rotating plane mirror, 4 is a rotation axis, 5 is an object to be measured, and 6 is a TV camera. Figure 1 1: Light source 4, rotation axis Figure 2 Figure 3

Claims (1)

[Claims] A plurality of light sources that emit linear light in a plane perpendicular to the plane toward a point within the plane, and a plurality of gratings simultaneously in any direction by reflecting each of the linear lights. A filament comprising a rotating plane mirror placed at the one point for projection and whose rotation axis is perpendicular to the plane, and identification means for identifying each filament light from the plurality of light sources. light projection device.