JPH07253320A - Controller for light source of optical scanning type displacement sensor - Google Patents

Abstract

PURPOSE:To simply and precisely regulate the directivity of a light beam output from a light source. CONSTITUTION:An eccentric rivet 7 having an eccentric pin engaging with a groove provided on the outer circumference of a cylindrically formed light source is provided on a holder 12 wherein the light source 1 is rotatably housed around its axis. The light source 1 is rotated around its axis by the rotation operation of the rivet 7 and the long axial direction of a light beam whose cross section is elliptical is regulated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adjusting mechanism of a light-projecting element in an optical scanning displacement sensor for measuring the distance to an object to be measured and the inclination (shape) of the object to be measured by optical triangulation. It is a thing.

[0002]

2. Description of the Related Art An optical scanning type displacement sensor used for measuring a distance to an object to be measured and a shape of the object to be measured in a non-contact manner is shown in FIG. And a light projecting unit including a light projecting optical system 2 that condenses the light beam output from the light projecting element 1 and a scanning device 3, a light receiving optical system 4, and a detection that is a one-dimensional position detecting element (PSD). It is formed as a device including a light receiving portion including the element 5.

When the object to be measured 6 is irradiated with the light beam output from the light projecting section and the reflected light is received by the light receiving section, FIG.
As shown in FIG. 5, the position of the focused spot formed on the detection element 5 by the light receiving optical system 4 in the light receiving section changes according to the distance to the object 6 to be measured. Since the position signals I ₁ and I ₂ which are a pair of current outputs that are contradictory to each other depending on the position of the focused spot between the electrodes on both sides are output, the distance to the measured object 6 can be measured. Further, since the scanning direction and the both-end electrode direction of the detection element 5 are arranged orthogonally to each other, the shape of the surface of the measured object 6 in the scanning direction can be determined by the scanning.

Here, the light projecting element 1 is a semiconductor laser.
, The output light beam has a circular cross-sectional shape.
It has an oval shape, not a shape. At this time, as shown in FIG.
As described above, the long axis direction of the light beam B coincides with the scanning direction.
In other words, that is, as shown in FIG.
The minor axis direction of the light spot S is the direction connecting both electrodes.
If this is the case, distance detection accuracy will increase and
As shown in FIG. 9, the focused spots Sa and Sb at the end are
Even if the light is focused on the detection element 5, as shown in FIG.
Since the intensity distribution is the same for both focused spots Sa and Sb
And the position signal I ₁, I₂The ratio of
The flatness of the surface of the fixed object 6 is output as it is.

However, when the major axis direction of the light beam having an elliptical cross section output from the light projecting element 1 is not parallel to the scanning direction (not perpendicular to the both end electrode direction of the detecting element 5), FIG. As shown in FIG. 10, since the focusing spots Sa and Sb are applied to the detection element 5 at both ends in the scanning direction differently, the light intensity distribution is as shown in FIG.
It depends on both focus spots Sa and Sb,
The ratio of the position signals I ₁ and I ₂ is also different at both ends in the scanning direction as shown in FIG. As a result, the measured object 6
It is determined that the shapes of the surfaces in the light beam scanning direction are different.

For this reason, in the optical scanning type displacement sensor, as shown in FIG. 11, the holder 12 for holding the cylindrical light projecting element 1 is provided on the flange portion 11 of the light projecting element 1. The projection 13 that engages with the positioning groove 10 serving as a reference slot is provided to hold the light projecting element 1 in consideration of its directivity. In the figure, 19 is a stopper.

[0007]

However, this holding is
Since the accuracy of the components of the light projecting element 1 (angle deviation of the element with respect to the package) and the accuracy of the component of the holder 12 that holds the light projecting element 1 are used, if the accuracy of each component is biased in one direction, it is ignored. There was a case where an angle deviation that could not be done occurred.

The present invention has been made in view of the above circumstances, and an object thereof is to easily and accurately adjust the directionality of a light beam output from a light projecting element. An object of the present invention is to provide a light projecting element adjusting mechanism of an optical scanning displacement sensor.

[0009]

SUMMARY OF THE INVENTION According to the present invention, however, the reflected light from the object to be measured of the light beam which is output from the light projecting element and which is scanned by the scanning device is condensed on the detecting element and detected. In an optical scanning displacement sensor that detects the distance to the object to be measured by the focusing position on the element, the outer circumference of the light emitting element is placed in a holder that houses a cylindrical light emitting element rotatably around its axis. An eccentric stud having an eccentric pin that engages with a groove provided on the surface, or a lever provided with a protrusion that engages with the groove provided on the outer peripheral surface of the light emitting element is rotatably attached. The feature is that this lever is projected to the outer surface of the holder.

[0010]

According to the present invention, the projection element can be rotated about its axis by rotating the eccentric stud or the lever to adjust the major axis direction of the light beam having an elliptical cross section.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the illustrated embodiments. Although the configuration of the entire optical scanning displacement sensor is the same as that shown in the above-mentioned conventional example,
As shown in FIG. 1, a cylindrical flange portion 1 on the rear end side
1 is provided with a groove 10 as a reference slot on the outer peripheral surface thereof. The light projecting element 1 is attached to the holder 12 together with the light projecting optical system 2, and the storage hole 14 of the holder 12 having a circular cross section and penetrating the holder 12 has a step portion on the rear end side. The rear end opening diameter is larger than the inner diameter. Also holder 12
Has a screw hole 15 and a through hole 16 for connecting the outer surface thereof and the rear end portion having the large diameter of the housing hole 14, and a set screw 17 is housed in the screw hole 15 and An eccentric tack 7 having an eccentric pin 70 at its tip is housed.

The light projecting element 1 is housed in the housing hole 14 of the holder 12 from the rear end opening, the front surface of the flange portion 11 is brought into contact with the stepped portion, and the stopper 19 is screwed to the holder 12 to form the stopper 19. By pressing the light projecting element 1 against the stepped portion by the ring-shaped elastic material 18 interposed between the light projecting element 1 and the light projecting element 1, the light projecting element 1 can be freely rotated around its axis without rattling. The holder 12 is attached in this state. At this time, the groove 10 on the outer peripheral surface of the light projecting element 1 is made to face the through hole 16.

When the eccentric stud 7 is inserted into the through hole 16 so that the eccentric pin 70 at the tip end is engaged with the groove 10 and the eccentric stud 7 is rotated, the light projecting element 1 moves as the eccentric pin 70 moves. It rotates around its own axis within a very small range. Therefore, the distance to the measured object 6 having a flat surface is measured, and the projection element 1 is adjusted by the eccentric stud 7 so that the output does not change in the scanning direction, and the adjustment is completed. The projecting element 1 is fixed by tightening the set screw 17. As a result, it is possible to eliminate the deviation in the major axis direction of the light beam having an elliptical cross section output from the light projecting element 1.

In the embodiment shown in FIGS. 3 and 4, a lever 8 is used instead of the eccentric stud 7. The lever 8 having a ring-shaped engaging piece 80 protruding in the axial direction and an operating piece 81 protruding in the outer peripheral direction is disposed between the elastic member 18 and the light projecting element 1 and is engaged. The coupling piece 80 is engaged with the groove 10 of the light projecting element 1, and the operation piece 81
Is projected to the outer surface of the holder 12 through the notch 20 formed in the holder 12. When the lever 8 is rotated by operating the operation piece 81 of the lever 8, the light projecting element 1 also rotates about the axis. To do. In this case, the lever 8 protruding to the outer surface of the holder 12 can be operated from the rear end surface side of the holder 12, which is the direction in which the light projecting element 1 is assembled. When the hole 82 is opened in the operation piece 81, the tool 9 can be inserted into the hole 82 and the operation piece 81 can be moved, so that the adjustment operation becomes easier. As shown in FIG. 5, even if the operation piece 81 is bent rearward, the adjustment operation becomes easy.

[0015]

As described above, in the present invention, the major axis direction of the light beam having an elliptical cross section is adjusted by rotating the light projecting element about its axis by rotating the eccentric stud or rotating the lever. It is possible to adjust the light projecting element easily and surely. Especially, when the eccentric stud is used, fine adjustment becomes easy, and when the lever protruding to the outer surface of the holder is used, the operation direction of the adjustment operation is not limited.

Further, when the light projecting element is held by the holder through the elastic material, it is possible to suppress the rattling of the light projecting element, so that the adjusting operation becomes easier.

[Brief description of drawings]

1 shows an embodiment, (a) is an exploded perspective view, (b)
Is a perspective view.

FIG. 2A is a vertical sectional view of the above, and FIG. 2B is a horizontal sectional view of the same.

FIG. 3 shows another embodiment, (a) is an exploded perspective view,
(b) is a perspective view.

FIG. 4 (a) is a vertical sectional view of the above, and FIG. 4 (b) is a horizontal sectional view of the same.

5A and 5B show another example of the above, wherein FIG. 5A is a perspective view and FIG. 5B is a perspective view of a lever.

FIG. 6 is a perspective view showing a schematic configuration of an optical scanning displacement sensor.

FIG. 7 is a side view of the above.

8A and 8B are views showing the light collecting position in the scanning direction of the above, wherein FIG. 8A is a plan view and FIG. 8B is a front view.

9A and 9B show a case where the major axis direction of a focused spot is normal, where FIG. 9A is a front view, FIG. 9B is a light intensity distribution diagram, and FIG. 9C is an output explanatory diagram.

10A and 10B show a case where the long axis direction of a focused spot is deviated, where FIG. 10A is a front view, FIG. 10B is a light intensity distribution diagram, and FIG. 10C is an output explanatory diagram.

FIG. 11 is an exploded perspective view of a conventional example.

[Explanation of symbols]

 1 Light emitting element 7 Eccentric stud 12 Holder

Claims (4)

[Claims] 1. The object to be measured is focused on a detection element by converging light reflected from the object to be measured, which is a light beam output from the light projecting element and scanned by the scanning device, on the detection element. In an optical scanning type displacement sensor that detects the distance to, a holder that rotatably houses a cylindrical light emitting element is engaged with a groove provided on the outer peripheral surface of the light emitting element. An illuminating element adjusting mechanism for an optical scanning displacement sensor, characterized in that an eccentric stud having an eccentric pin is provided. 2. The object to be measured is focused on the detection element by collecting reflected light from the object to be measured, which is a light beam output from the light projecting element and scanned by the scanning device, on the detection element. In an optical scanning type displacement sensor that detects the distance to, a holder that rotatably houses a cylindrical light emitting element is engaged with a groove provided on the outer peripheral surface of the light emitting element. A projection element adjusting mechanism for an optical scanning displacement sensor, characterized in that a lever having a protrusion is rotatably attached and the lever is projected to the outer surface of the holder. 3. The light projecting element adjusting mechanism of the optical scanning displacement sensor according to claim 1, wherein the light projecting element is held by a holder with an elastic material. 4. The light-projecting element adjusting mechanism for an optical scanning displacement sensor according to claim 2, wherein the protrusion of the lever on the outer surface of the holder is bent in a direction opposite to the light-projecting direction.