JPS59201004A - Laser light projecting device - Google Patents

Abstract

PURPOSE:To replace a laser projector body without putting an optical axis out of order when it is used as a visual sensor, by providing a distance adjusting mechanism in the optical axis direction between a semiconductor laser and a rod-like microlens, and a position adjusting mechanism of the semiconductor laser. CONSTITUTION:A fixing plate 3 to which a semiconductor laser 1 is fixed is clamped temporarily to a lens fixing part 5 by utilizing a hole 9 by a screw 8 passing through a coil spring 7, the fixing plate 3 is moved within a range of a tolerance of the hole 9 so that the center of a cross line for showing an optical axis on a laser light detecting fluorescent plate 13 placed at a prescribed distance L from a laser projector body 10 coincides with the center of a laser light 12, and a laser position is adjusted on the surface falling at a right angle with an optical axis 11. Also, the optical axis 11 is made to coincide with an optical axis of a rod-like microlens 4. The screw 8 is clamped gradually so that a beam diameter D of the laser light 12 becomes a prescribed size, and a distance between the semiconductor laser 1 and the rod-like microlens 4 is adjusted.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is applicable to devices that automate arc welding, such as arc welding robots or dedicated q-visual sensor devices that detect weld lines, visual inspection devices, etc. The present invention relates to a laser beam projection device used in combination with an optical sensor as a sensor.

Conventional configuration and its problems The configuration of a conventional laser beam projector is a combination of a commercially available lens (for example, a microscope objective lens) and a semiconductor laser.
Alternatively, there is one that combines a thick microlens with high transmittance and a semiconductor laser. However, although the former is inexpensive, since it is a combination lens, the transmittance is extremely low due to scattering of laser light at the lens interface.
However, since the current aperture is large, there is the problem that the shape of the light projecting section is large, and the latter has the problem of being extremely expensive, although it has excellent transmission efficiency because it is a special lens.

OBJECTS OF THE INVENTION The present invention solves the above-mentioned drawbacks of the conventional art, and has high transmittance, is small, lightweight, and inexpensive, and facilitates optical axis adjustment between a semiconductor laser and a rod-shaped microlens. It is an object of the present invention to enable replacement of a laser projector main body without disturbing the optical axis of the laser projector main body and a bearing part when used as a sensor.

Structure of the Invention To achieve this object, the present invention includes a semiconductor laser,
A laser fixing plate for mounting the semiconductor laser, a rod-shaped microlens facing the semiconductor laser, a lens fixing part for fixing the rod-shaped microlens, and an optical axis between the semiconductor laser and the rod-shaped microlens. A method of attaching a laser projector body equipped with a direction distance adjustment mechanism and a position adjustment mechanism of the semiconductor laser on a plane perpendicular to the optical axis to a receptacle to which the projector frame is fixed will be described below as an example of the present invention. An embodiment will be described with reference to FIGS. 1 to 8 of the drawings.

The semiconductor laser 1 is fixed to a laser fixing plate 3 with screws 2, and the rod-shaped microlens 4 is fixed to a lens fixing part 5 with an adhesive 6. The laser fixing plate 3 to which the semiconductor laser 1 is fixed is fastened to the lens fixing part 5 with three screws 8 passed through the coil spring 7 using the screw holes 9. When tightening the screw 8, temporarily tighten the screw 8, and as shown in FIGS. 11 (that is, the optical axis) and the center 0 of the laser beam 12, move the laser fixing plate 3 within the range of the tolerance of the screw hole 9, which is sufficiently large with respect to the diameter of the screw 8, so that the plane perpendicular to the optical axis 11 is aligned. Adjust the laser position at the top. That is, the optical axis 11 of the laser beam 12 and the optical axis of the rod-shaped microlens 40 are made to coincide. Next, a fluorescent plate 1 for laser light detection is located at a certain distance from the laser projector main body 10.
3, tighten the three screws 8 in sequence so that the beam diameter of the laser beam 12 becomes a predetermined size, and adjust the distance between the semiconductor laser 1 and the rod-shaped microlens 4 in the direction of the optical axis 11. do.

Laser fixing plate 3 with coil spring 7 around the screw 8
The distance between the semiconductor laser 1 and the rod-shaped microlens 4 can be finely adjusted by the repulsive force. Note that an elastic body such as an O-ring can also be used in place of the coil spring 7.

In this embodiment, the receptacle 16 is fixed to the projector frame 15 shown in FIG. 6 with screws 17, and the laser projector main body 1
0, the laser projector main body 1o is fixed with screws 18. This structure has great advantages for the following reasons. Floodlight frame 15 as a product
, and the receptacle 16 with exactly the same specifications as the standard jig, and after fitting the laser projector main body 1o thereto, align the optical axis, align the beam diameter, and align the optical axis 11 at the angle θ.
By preparing the laser projector main body 10 with the ζ optical axis 11 and the light receiving axis 11' adjusted, when the semiconductor laser 1 needs to be replaced due to failure or deterioration, simply by replacing the laser projector main body 10, the ζ optical axis 11 can be adjusted. Misalignment of the light-receiving axis 11' or beam diameter may also occur in the laser projector body 10. As long as the machining precision of the receptacle 16 and the projector frame 15 is within the range, there is no problem at all in practice.

The necessity of aligning the optical axes of the semiconductor laser 1 and the rod-shaped microlens 4 and adjusting the distance between them is due to the relative position error between the stem of the semiconductor laser 1 and the laser chip, and if the above adjustment is not performed. This is completely unusable.

Next, the necessity of adjusting the transmitting and receiving light axes based on the angle θ between the optical axis 11 and the light receiving axis 11' will be explained.

The present embodiment is used for a welding cross-sensing device for the purpose of recognizing the groove shape of a workpiece 19 and detecting a weld line 20, as shown in FIGS. 6 to 8. Specifically, the workpiece 19 is irradiated with laser light 12 from the projector frame 15 as a sensor head, and the scattered light from the irradiation point 21 on the light receiving axis 11' is imaged on the sensor 23 by the imaging lens 22. The sensor output is calculated by the controller 24 and the beam irradiation position 21 is output as a distance from the projector frame 15. By swinging the projector frame 16 in the X direction, the irradiation point 21
The groove shape 25 of the workpiece 19 is obtained as a continuous line, and after pattern recognition processing, the gap value G and the gap center position C are detected. Place the laser beam irradiation point 21 on the projector frame 1
A reference distance is required in order to output the distance from the optical axis 11 and the optical axis 1.
The adjustment at the angle θ with respect to 1' is the setting of the reference distance.

Adjustment of the beam radius at the reference distance is also a factor that affects sensing accuracy.

Effects of the Invention According to the present invention, it is possible to easily adjust the distance between the optical axis and the three, which requires a complicated and precise process by combining a rod-shaped microlens and a semiconductor laser, and to provide a light projector for application to a laser beam and a light receiving sensor. Eliminates the need to adjust the transmitting and receiving optical axes when replacing.
By making it possible to apply rod-shaped microlenses, we have achieved high transmittance (more than twice that of conventional microscope objective lenses, equivalent to high-transmittance thick lenses), while also being significantly smaller and lighter than conventional microscope lenses. Moreover, it has an excellent effect of realizing cost reduction.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a laser projector main body used in a laser beam projector according to an embodiment of the present invention, FIG. 2 is a side view of the same, and FIGS. 3, 4, and 5 show optical axis adjustment and FIG. 6 is a sectional view of the projector frame to which the laser projector main body is attached, and FIGS. 7 and 8 are explanatory views explaining the application of the laser projector. 1...Semiconductor laser, 3...Laser fixing plate, 4...Rod-shaped microlens, 6...
... Lens fixing part, 7 ... Elastic body (coil spring), 8 ... Screw, 9 ... Hole for screw, 1o ... Laser Floodlight body, 11...
・Optical axis, 15... Emitter frame, 16...
receptacle.

Claims (3)

[Claims] (1) A semiconductor laser, a laser fixing plate for mounting the semiconductor laser, a rond-shaped microlens facing the semiconductor laser, a lens fixing part for fixing the rond-shaped microlens, and a rond-shaped microlens for fixing the rond-shaped microlens for the semiconductor laser. A laser beam projector in which a laser projector main body, which is equipped with a distance adjustment mechanism between lenses in the optical axis direction and a position adjustment mechanism for the semiconductor laser on a plane perpendicular to the optical axis, is attached to a receptacle fixed to a projector frame. . (2) A laser beam projecting device according to item (1) of the laser fixed enclosure as a distance adjustment mechanism in the optical axis direction. (3) As a position adjustment mechanism for the semiconductor laser on a plane perpendicular to the optical axis, the diameter of the screw hole in the laser fixing plate is made larger than the diameter of the screw, making it possible to adjust the sliding movement of the laser fixing plate. A laser beam projection device according to claim (1).