JPS63238419A - Reflection type photoelectric sensor - Google Patents

Abstract

PURPOSE:To easily adjust the converging position of projected beam, by providing a projected beam converging point position adjusting means moving a beam projecting optical system from the outside of a case. CONSTITUTION:This photoelectric sensor consists of the semiconductor laser 1, PSD 2, beam projecting lens 3 and beam receiving lens 4 received in a case consisting of a case main body 115 and a lid, and an adjustment knob 20 made freely rotatable is fitted to the main body 15. When the knob 20 is rotated, the distance between the laser 1 and the lens 3 is changed to make it possible to change the converging point position of projected beam alpha. At this time, since the knob part 201 of the knob 20 protrudes to the outside of the case and the knob 20 can be rotated from the outside of the case, the converging point position of the projected beam alpha can be easily adjusted from the outside of the case. Therefore, it is unnecessary to disassemble the main body 15 in order to adjust a position and positional adjustment can be performed with good accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a reflective photoelectric sensor used in triangulation type photoelectric switches and the like.

[Background technology]

Recently, a reflective photoelectric sensor used in triangulation type photoelectric switches and the like has been developed.

As shown in Figure i5, the reflective photoelectric sensor A includes a semiconductor laser (light emitting element) 1 and a semiconductor device detection element (detection means, hereinafter referred to as "PSDJ") 2 housed in a case 15.
, a light projecting lens (light projecting optical system) 3, and a light receiving lens (light receiving optical system) 4. The light projection lens 3 converts the light emitted from the semiconductor laser 1 into a light beam α having a convergence point at a predetermined position, and projects the light onto the object B to be detected. The projected beam α has a cross-sectional shape as shown in FIG. The light receiving lens 4 converts the diffusely reflected light β of the projected light beam α diffusely reflected by the detected object B into a PSD2.
The light collection path can be directed to the light collection surface of the This reflective photoelectric sensor A is designed to condense light at a position corresponding to the distance to the detected object B. For example, when detected object B is at position X, diffuse reflected light β is focused at position X, and when detected object B is at position Y, diffuse reflected light β is focused at position y. It is designed to allow P
The SD2 outputs a detection signal corresponding to the focal position. That is, when the detected object B is at position X, a detection signal corresponding to the condensed position It is supposed to be done. Therefore, the position of the detected object B can be known by determining the output signal. In other words, it can be used as a sensor for measuring the distance to the detected object B. In addition, since the light is focused at the position X only when the detected object B is at the position X, and the detection signal corresponding to the focused position X is output, the detected object B is at the position X. You can see whether it exists or not at the location. Therefore, it can also be used as a sensor for checking the presence or absence of an object to be detected within the detection area.

By the way, in conventional reflective photoelectric sensors, the convergence point of the projected beam α is fixed at a predetermined position after assembly.
The convergence point position could not be adjusted. Therefore, the size of the cross section of the projected beam α at a given distance from the sensor is:
It was constant. Therefore, there is a problem in that if the detected object B located within a predetermined distance is smaller than the cross section of the projected beam α, it cannot be detected. Therefore, in such a case, the cross section of the projected beam α at the position of the detected object B is changed by changing the position of the projection lens 3 relative to the semiconductor laser 1 so that the convergence point position of the projected beam α becomes closer. It needed to be smaller.

In addition, a reflective photoelectric sensor uses the diffusely reflected light from the detected object B to perform distance measurement, etc., but when the detected object B is made of metal, slight irregularities on the surface or processing Due to the effects of scratches, rolling direction, etc., as shown in FIG. 7, the specularly reflected light component was mixed with the diffusely reflected light β, causing errors (malfunctions). In such a case, by increasing the projection area on the surface of the object to be detected 8 and canceling out the light of the regular reflection component mixed with the diffuse reflection light, it is possible to get closer to the diffuse reflection as shown in Figure 8. Therefore, errors (malfunctions) can be prevented. Therefore, in the latter case,
Contrary to the former case, the position of the projection lens 3 with respect to the semiconductor laser 1 is changed so that the convergence point position of the projection beam α becomes distant, and the cross section of the projection beam α at the position of the projecting object B is changed. It needed to be bigger.

As described above, adjust the convergence point position of the projected beam α (
If the convergence point position can be made variable, it can be used in more areas and the detection accuracy can be improved.

However, in conventional reflective photoelectric sensors, the position of the light emitting lens 3 relative to the semiconductor laser 1 cannot be adjusted after assembly, which is necessary to adjust the position of the convergence point of the emitted light beam α. had to be disassembled one by one. Therefore, it was very time consuming. Moreover, it was difficult to make adjustments when the device was disassembled, and even if it was possible to make adjustments in the disassembled state, there were cases where the adjustments were incorrect when reassembled. therefore,
Accurate adjustments could not be made.

[Purpose of the invention]

In view of the above circumstances, an object of the present invention is to provide a reflective photoelectric sensor that can easily adjust the position of the convergence point of a projected beam.

[Disclosure of the invention]

To achieve the above object, the present invention includes a light emitting element, a light detecting means, and a light projecting device for converting the light emitted from the light emitting element into a light beam having a convergence point at a predetermined position and projecting the light onto an object to be detected. A reflective photoelectric sensor comprising an optical system and a light-receiving optical system for condensing diffusely reflected light of the projected light beam diffusely reflected by the detected object onto the detecting means, and these are housed in a case. , a reflective photoelectric sensor is provided with a projection beam convergence point position adjusting means for moving the projection optical system from outside the case so as to make the projection beam convergence point position variable. This is the summary.

Hereinafter, one embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows a cross-sectional view of a main part of an embodiment of a reflective photoelectric sensor according to the present invention, and FIG. 2 shows a cross-sectional view of the main part of the embodiment in an exploded state. Ori,
FIG. 3 shows the entire embodiment in an exploded state.

As shown in these figures, this reflective photoelectric sensor is a reflective photoelectric sensor used in a triangular distance measuring photoelectric switch, and includes a semiconductor laser ( A light emitting element) 1, a PSD (detection means) 2, a light projecting lens (light projecting optical system) 3, and a light receiving lens (light receiving optical system) 4 are provided.

゛The semiconductor laser l is inserted into the optical tube 61 formed in the optical block body ε, and this ? ,? It is attached to the rear of J61. The optical barrel 61 has an adjustment knob 2 which will be described later.
0 guide hole 611 is penetrated. Light projection lens 3
is attached to the light projecting lens fixing tube 5. This light projecting lens fixing tube 5 is also inserted into the optical tube 61 and arranged at the front thereof. Therefore, the projection lens 3 is
It is located in front of the semiconductor laser 1 in the optical axis direction. The light emitted from the semiconductor laser 1 is turned into a light beam having a convergence point at a predetermined position and projected onto the object to be detected. The light projection lens fixed tube 5 is slidable in the optical axis direction of the semiconductor laser 1 using the inner surface of the optical tube 61 as a guide. A t551 is formed on the outer circumferential surface of the light projecting lens fixed cylinder 5, which is perpendicular to the optical axis direction of the semiconductor laser 1. The rear end of the optical tube 61 is closed with a plate 7 fixed to the optical tube 61 with screws 8. Only the terminals of the semiconductor laser 1 protrude from the plate 7.

The light receiving lens 4 is fixed to the front part of the light receiving lens fixing frame 10. The PSD 2 is fixed to a PSD mounting frame 9. The PSD mounting frame 9 is fixed to the rear part of the light receiving lens fixing frame 10 with pins 11 and screws 12. Therefore, the light receiving lens 4 is located in front of the PSD 2 in the optical axis direction. Then, the diffusely reflected light from the object to be detected is condensed onto the condensing surface of the PSD 2.

On the front surface of the optical block body 6, there are a window 62 for passing the projected beam and a window 63 for passing the diffusely reflected light.
is formed. These windows 62.63 are glass filters 13.1 through which the projected beam and the diffusely reflected light can pass.
It is blocked by 4.

The optical block main body 6 is fixed to the case main body 15 with screws 16 so that its rear part faces into the case main body 15. Optical block body 6 and case body 15
The space between them is sealed with a seal 17. The case body 15 has an opening formed therein. This opening is
It is closed with a lid 18 fixed to the case body 15 with screws 19.

The case body 15 has a rotatable adjustment knob 20.
is installed. The adjustment knob 20 includes a knob portion 201, a guide portion 202, and an eccentric shaft 203. The knob portion 201 is exposed outside the case body 15 (case). The guide portion 202 is inserted into a guide hole 611 formed in the optical tube 61 without any gap. This allows the adjustment knob 20 to rotate using the guide hole 611 as a guide. The eccentric shaft portion 203 is eccentric with respect to the guide portion 202, that is, with respect to the rotation axis, and is fitted into a groove 51 formed in the light projecting lens fixing cylinder 5.

As shown in FIGS. 1 and 4, the adjustment knob 20 and the projection lens fixing frame 5 are in the state shown by the solid line, and the distance between the semiconductor laser l and the projection lens 3 is 11 degrees. Suppose there is. From this state, turn the adjustment knob 20 to 90°.
When rotated, the eccentric shaft portion 203 rotates around the rotation axis and comes to the position shown by the two-dot chain line. This eccentric shaft portion 203
With this movement, the projection lens fixing barrel 5 is slid using the optical barrel 61 as a guide, and is moved to the position shown by the two-dot chain line. Therefore, the light projecting lens 3 fixed to the light projecting lens fixing tube 5 is also moved, and the distance between the semiconductor laser 1 and the light projecting lens 3 becomes 12. In this way, by rotating the adjustment knob 20, the distance between the semiconductor laser 1 and the projection lens 3 can be changed. The convergence point position of the projected beam is
Since it is determined by the distance between the semiconductor laser 1 and the projection lens 3, if the distance changes, the position of the convergence point of the projection beam also changes. In other words, this reflective photoelectric sensor moves the light emitting lens 3 by rotating the adjustment knob 20, changing the distance between the semiconductor laser 1 and the light emitting lens 3, and converging the light beam. This allows you to change the point position. Moreover, the knob 201 of the adjustment knob 2o is exposed outside the case, and the adjustment knob 20 can be rotated from outside the case, so the position of the convergence point of the emitted light beam can be easily adjusted from outside the case. It has become. That is, the adjustment knob 20 and the projection lens fixing tube 5 serve as a projection beam convergence point position adjusting means for moving the projection lens 2 from outside the case so as to make the projection beam convergence point position variable. There is.

As described above, this reflective photoelectric sensor allows the position of the convergence point of the emitted light beam to be easily adjusted from outside the case, so there is no need to disassemble it for position adjustment. I can make good adjustments.

The operating principle of this reflective photoelectric sensor is the same as the conventional one.

The reflective photoelectric sensor according to the present invention is not limited to the above embodiments. The light emitting element may be other than a semiconductor laser. The detection means may also be other than PSD. The light projecting optical system and the light receiving optical system may also use systems other than lenses. The projection beam convergence point position adjusting means may have a structure in which a pinion gear is formed on the adjustment knob, and a rack that meshes with the pinion gear is formed on the projection lens fixing tube along the optical axis direction of the light emitting element. [Effects of the Invention] As seen above, the reflective photoelectric sensor according to the present invention includes a light emitting element, a light detecting means, and converts the light emitted from the light emitting element into a light beam having a convergence point at a predetermined position. A light projecting optical system for projecting light onto the detected object, and a light receiving optical system for converging the diffusely reflected light of the projected light beam diffusely reflected by the detected object onto the detecting means. In the reflective photoelectric sensor housed in the cable λ,
The device is characterized in that a projected beam convergence point position adjusting means is provided for moving the light projecting optical system from outside the case so as to vary the convergence point position of the projected light beam.

Therefore, the position of the convergence point of the projected beam can be easily adjusted.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of the main parts of an embodiment of a reflective photoelectric sensor according to the present invention, FIG. 2 is an exploded perspective view of the main parts of the embodiment, and FIG. 3 is an exploded perspective view of the main parts of the embodiment. Fig. 4 is an explanatory diagram of the operation of the main parts of the embodiment, Fig. 5 is a schematic explanatory diagram showing the operating principle of the reflective photoelectric sensor, and Fig. 6 is an exploded perspective view of the projecting beam. 7 is a schematic explanatory diagram showing the reflected state of the beam when the position of the convergence point of the projected beam is not adjusted.
FIG. 8 is a schematic explanatory diagram showing the reflected state of the beam when the position of the convergence point of the projected beam is adjusted. 1... Semiconductor laser (light emitting element) 2... PSD
(Detection means) 3... Lens for light emission (optical system for light emission) 4... Lens for light reception (optical system for light reception) 5...
・Lens fixing tube for light projection 15...Case body 18・
...Lid 20...Adjustment knob B...Detected object α
...Light beam β...Diffuse reflected light Agent Patent attorney Takehiko Matsumoto Figure 1 Figure 4 Figure 5

Claims (1)

[Claims] (1) A light emitting element, a light detecting means, a light projection optical system that converts the light emitted from the light emitting element into a light beam having a convergence point at a predetermined position, and projects the light onto an object to be detected, and the object to be detected. a light-receiving optical system that focuses diffusely reflected light of the projected light beam on the detection means, and these are housed in a case. A reflective photoelectric sensor characterized in that a projection beam convergence point position adjusting means is provided for moving the projection optical system from outside the case so as to make the position variable.