JPH03167411A - Scanning head for non-contact type digitizer - Google Patents

Abstract

PURPOSE:To make a scanning head compact and light by constituting a light projecting part with an optical system wherein the images of the light beams emitted from two light sources are formed as light spots at two separated points on the surface of an object. CONSTITUTION:Voltages are applied on semiconductor elements for light sources 11 and 14. The laser light beams emitted from the light sources 11 and 14 become parallel light beams through lenses 12 and 15. The parallel light emitted from the lens 12 reaches a lens 13 through a half mirror 16. The parallel light from the lens 15 is refracted at a specified angle with a reflecting surface 16a of the mirror 16 and reaches the lens 13. The image of light spots are formed on a point (a) and a point (b) on the surface of a model 2. The image of reflected light from the light spot at the point (a) is formed on a detecting element 18 through a lens 20. The image of the reflected light of the light spot at the point (b) is formed on a detecting element 19. The images of the light spots on the element 18 and 19 are displaced by the irregularties of the surface of the model by the movement of the model 2. The amounts of the displacements are detected with the element 18 and 19 and inputted into a digitization controlling device.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a scanning head for a digitizer that digitizes a model shape and generates an NC program.

Conventional technology Scanning heads for non-contact digitizers detect changes in the bright spot irradiated onto the model surface with high precision, trace the scanning head while keeping the distance from the model surface constant, and trace the changes on the model surface. It detects coordinate values continuously. At this time, in order to automatically move the axis of the scanning head or model, it is necessary to calculate the velocity vector. For this reason, in order to simultaneously detect changes in the bright spots at two locations on the axis of movement that are separated by a certain distance on the model surface, a method was adopted in which sensors of the same type were placed side by side and each sensor performed simultaneous detection. ．． Problems to be Solved by the Invention The method of arranging sensors of the same type in parallel, as described in the prior art, has the problem that the entire scanning head becomes large, narrowing the working area as a digitizer and impairing operability. are doing. The present invention was made in view of the above-mentioned problems of the conventional technology, and its purpose is to provide a small, lightweight, non-contact digitizer that can simultaneously measure two bright spots on the axis of movement. The aim is to provide a scanning head. Means for Solving the Problems In order to achieve the above object, in the scanning head for a non-contact digitizer of the present invention, the light projecting section emits bright spots at at least two distant points on the surface of the object emitted from two light sources. It consists of an optical system that forms an image. Also, an optical system that images light emitted from two light sources as bright spots on at least two distant points on the surface of an object, and one optical system that images bright spot images of the two bright spots as two points. The system includes a detection element that simultaneously outputs the displacement amount of each of the bright spot images.

Effect The light emitted from the two light sources forms bright spots at two distant points on the model surface by the optical system of the light projector.

The optical system of the light receiving and detecting section forms a bright spot image on each of the two detection elements. This bright spot image is displaced according to the unevenness of the model surface due to movement of the scanning lid or model, and the amount of displacement is output from the detection element. Then, based on this output data, the shape of the model surface and velocity vector are determined. Embodiment An embodiment will be explained with reference to FIGS. 1 to 4. In a well-known digitizer, an X provided on bend 1
On the axial guide, a table 3 for moving the model 2 is movably ixm, and on columns 4 erected on both sides of the bed 1, a crossbeam 5 with a Y-axis guide is installed.
is fastened. A soil shaft head 6 is movably installed on the guide of the crossbeam 5, a tracer quill 7 is provided on the main shaft head 6 so as to be movable in the Z-axis direction, and an optical scanning head 8 is mounted at the tip of the quill 7. It is attached removably. There is a light projector inside the zero body 9 of the scanning hesode 8!
The OA and the light receiving detector 10B are arranged in a V-shape at a predetermined angle θ in a plane perpendicular to the scanning direction. A semiconductor element 11 that emits a laser beam and serves as a light source is mounted facing downward on the upper part of the light projecting section 10A in the main body 9, and a lens 12 for converting the diffused laser beam into a parallel beam is installed below it. incorporated, lens 12
A lens 1 for imaging a bright spot on the model surface below
3 is installed. Furthermore, a lens 1 is attached to the light projecting section 10A.
At the center of the semiconductor element l1 and the lens 13, a semiconductor 14 and a lens 15, which are the same as the semiconductor element l1 and the lens 12, are aligned parallel to the scanning direction so that an optical axis perpendicular to the optical axis passing through the lens 12.13 is obtained. Installed in-plane. At the intersection of both optical axes, one side 16a is a mirror surface that reflects light, and the opposite surface 1 (ib is a unidirectional light i3 that reflects light iJ1). By adjusting the mounting angle θ'' of this half ξ roller 16, the reflection optical axis is slightly inclined with respect to the straight optical axis passing through the lens 12. Two points a and b separated by
It is designed to image a bright spot on each side. This 2
The distance 1x between points a and b is, for example, 2 m for vector calculation.
It is held accurately at position l, and the light from semiconductor element 11 is placed at position a.
Furthermore, the light from the semiconductor element 14 is imaged at position b.

Furthermore, within the main body 9, a lens 20 is provided which captures the reflected light of the bright spots on the model surface of the light receiving/detecting section 10B and focuses the respective bright spot images onto the two detection elements 18 and 19. The detection elements 18 and 19 can be CCD image sensors or the like, and two of them are installed side by side at positions corresponding to the respective bright spot images with an interval l° between them. The CCD element row direction is determined by the imaging magnification and distance l, and is arranged so that the direction of the CCD element column coincides with the moving direction of the bright spot image that moves in response to changes in the model surface. It is designed to detect movement. A digitizing control device 2l that generates NC data based on the output data of the detection elements 18 and 9 is installed near the bottom 1.

Next, the operation of this embodiment will be explained. Semiconductor element 1
A voltage is applied to 1.14 to emit a laser beam, and the diffused laser beams are each turned into parallel light by a lens 12.15. Then, one parallel light coming out of the lens 12 passes through the half mirror 16 and reaches the lens 13 in a straight line.
The other parallel end coming out of the lens 15 reaches the lens 13 as a thousand line rays that are refracted at a predetermined angle close to the right angle by the reflective surface 16a of the half mirror I6, and each thousand line rays are reflected on the surface of the model 2. A bright spot is formed at point a and point b, respectively. The reflected light from the bright spot at point a is captured by the lens 20 and forms a bright spot image on the detection element 18, and the reflected light from the bright spot at point b forms a bright spot image on the detection element 19. Then, the bright spot image on the detection element 18.19 is displaced due to the unevenness of the model surface due to the movement of the model 2 or the scanning head 8, and the amount of this displacement is detected by the detection element 18.19 and input to the digitization control device 21. . Then, the distance from the bright spot on the model surface to the scanning head 8 is always constant by two-axis control of the quill 7 or by X.
Y-axis control is performed, and the coordinate values of the model surface are determined from the current values of the XY and Z axes and the scanning head data.
At the same time, the slope angle and speed vector of the model surface are calculated from the deviation values of the data of the detection elements 18 and 19, the feed axis speed is determined, and the NC data is generated.

Effects of the Invention Since the present invention is designed as described above, it produces the following effects. The light emitted from the two light sources is imaged as bright spots on two separate points on the model surface by the optical system of the light projecting section, and the reflected light from these two bright spots is focused by the optical system of the light receiving and detecting section. A bright image is formed on the detection element, and the displacement of the bright spot image is simultaneously detected by the detection element, so there is no need to install sensor heads of the same type in parallel, and the scanning head can calculate velocity vectors. It is possible to achieve smaller size and lighter weight.

[Brief explanation of the drawing]

Fig. 1 is a front cutaway view of the light emitting part and light receiving detection part of the scanning head, Fig. 2 is a side cutaway view showing the light emitting part of the scanning head, and Fig. 3 is A-A of the construction drawing showing the detection element. The line view, FIG. 4, is a diagram of the digitizer. 2...Model 8...Scanning head 10A...Light emitter 10B...Light reception detection unit 11.14...Semiconductor elements for light source 12, 13, 15.20...Lens

Claims (2)

[Claims] (1) The light emitter (
An optical scanning head (8
), the light projector is configured to emit light from two light sources (11, 14) at least two distant points (a,
b) The optical system (12, 13, 15,
16) A scanning head for a non-contact digitizer, comprising: (2) The light emitter (
An optical scanning head (8
), the optical system (12, 13, 15, 16 )
, an optical system (20) that forms the bright spot images of the two bright spots into two points, and a detection element (18, 19) that simultaneously outputs the displacement amount of each of the bright spot images. A scanning head for a non-contact digitizer, comprising: