JPH06251669A - Reflection type photoelectric switch - Google Patents

Abstract

PURPOSE:To make setting work of a reflection type photoelectric switch easy by making it possible to observe the detecting operation region with eyes at the time of setting. CONSTITUTION:Visible light parallel to a light projecting axis B is projected from a light projecting part 7 and also visible light parallel to a light receiving axis A is made to be projected from a light receiving part 6 at a time of photoelectric switch setting and thus the point C where the light receiving axis A and the light projecting axis B cross each other, that is the detecting operation region, is made possible to be observed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reflective photoelectric switch, and more particularly to a structure that facilitates setting thereof.

[0002]

2. Description of the Related Art A reflection type photoelectric switch is provided with a light projecting section composed of a condenser lens and a light projecting element and a light receiving section composed of a condensing lens and a light receiving element on the front surface of a case. The axes intersect at the front of the case. That is, when the object to be detected reaches the intersecting range of the light emitting axis and the light receiving axis, the light emitted from the light projecting portion hits the object to be detected and is reflected there to become reflected light, and this reflected light is incident on the light receiving portion. Then
The presence or absence of the detected object is detected through the light receiving element.

[0003]

The reflection type photoelectric switch has the object to be detected in accordance with the path of the object to be detected, that is, the crossing range of the light projecting axis of the light projecting section and the light receiving axis of the light receiving section. Must be installed to pass through. For this reason, a stable operation indicator lamp that displays the operation of the photoelectric switch and a detection output indicator lamp that lights up when the photoelectric switch detects the detected object are provided in the case, and when the detected object is placed on the front surface of the case, Setting the photoelectric switch while checking the operation of the indicator light. Alternatively, a light emitting element that emits visible light is used, and the photoelectric switch is set depending on the confirmation that the visible light is projected on the object to be detected and the lighting condition of the indicator lamp. However, the setting of such a photoelectric switch determines the arrangement of the photoelectric switch in consideration of the optical axis of the photoelectric switch being in the direction perpendicular to the lens and the passing position of the object to be detected, or supplying power to the photoelectric switch. Then, confirm the position of the detected object and the photoelectric switch with the indicator lamp, or determine the photoelectric switch position while checking the position of the detected object and the photoelectric switch with the visible light from the light emitting element and the indicator lamp. Because
There is a problem that it is difficult to optimally arrange the photoelectric switch and it takes time to set.

Further, when the adjustment is performed within a limited range, or when it is used for an application such as limited reflection, the influence of a back object is only seen from the visible light from the light projecting element and the condition of the indicator lamp. Since the positional relationship between the object to be detected and the photoelectric switch is unclear, there is a problem that it takes a lot of time for adjustment. In view of the above problems, an object of the present invention is to provide a reflection type photoelectric switch whose setting is easy.

[0005]

In order to solve the above-mentioned problems, the present invention provides a light projecting section and a light receiving section on the front surface of a case, and a light projecting axis from the light projecting section and a light receiving axis to the light receiving section. In the reflection type photoelectric switch, the and are made to intersect on the front surface of the case, and the presence or absence of the detected object is detected when the detected object passes through this intersection range. The visible light projection means for emitting visible light is provided, and the visible light projection means for emitting visible light parallel to the light receiving axis is provided at the light receiving portion. As a light source of visible light emitted from the light receiving part at this time, (1) a light emitting chip that emits visible light enclosed in a light receiving element of the light receiving part, (2) visible light provided in a position different from the light receiving element in the light receiving part (3) The visible light emitted from the light emitting element (3) stable operation indicator light may enter the light receiving section through the light guide tube, and the color of these light sources and the color of visible light emitted from the light projecting section should be different. Is also effective. Further, it is preferable to provide a switch for simultaneously turning on and off the respective visible light projecting means of the light projecting section and the light receiving section so that visible light is simultaneously emitted from the light projecting section and the light receiving section during setting.

[0006]

The visible light from the light projecting portion and the visible light from the light receiving portion intersect in front of the case. The visible light crossing range is the operation area of the photoelectric switch, that is, the area where the photoelectric switch can recognize the presence of the detected object and generate a detection output, and the visible light from the light projecting unit is included in this range. Since the visible light from the light receiving section and the light receiving section are overlapped with each other, the amount of light is increased to facilitate the visual inspection. Also, if the colors of both visible light are different, the operation area is a mixture of two colors. Visual confirmation becomes even easier.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a side sectional view showing an embodiment of the present invention. On the upper surface of a case 1, there is a stable operation indicator lamp 2 which lights up when power is applied to a photoelectric switch and the power supply voltage is stable. A detection output indicator lamp 3 that lights up when a detected object is detected is provided, and a switch 4 that turns on and off visible light emitted from a light receiving unit, which will be described later, is also installed, and both are equipped with a signal processing circuit or the like. Is connected to the electric circuit of the printed circuit board 5. Further, a light receiving portion 6 and a light emitting portion 7 are installed on the front side of the case 1, the light receiving portion 6 is provided with a lens 8 and a light receiving element 9, and the light emitting portion 7 is provided with a lens 10 and a light emitting element 11. ing.

As shown in FIG. 2, the light receiving element 9 includes a light receiving chip 12 and a light projecting chip 13 as a visible light projecting means for emitting another visible light.
Visible light emitted from is emitted through the central hole 12 a of the light receiving chip 12. That is, the visible light emitted from the spread light is received by the lens 8 shown in FIG.
The visible light is parallel to. On the other hand, the visible light from the light projecting element 11 as the visible light projecting means of the light projecting unit 7 is also converted into visible light parallel to the projection axis B by the lens 10. Since the light receiving axis A and the light projecting axis B are configured to intersect at a point C, the visible light from the light projecting portion 7 and the visible light from the light receiving portion 6 are in the vicinity of the point C (broken lines intersect in FIG. 1). Overlap),
This is the operating area. In this operation area, the amount of light is increased and it is easy to see. In addition, the visible light from the light receiving section 6 and the light projecting section 7
If the colors of the visible light from are different from each other, the two colors are mixed in the operation region, so that the visual observation is further facilitated.

FIG. 3 is a block diagram of an electric circuit printed on the printed circuit board 5. Explaining this electric circuit, the output of the oscillation circuit 101 that oscillates at a predetermined frequency is frequency-divided by a frequency dividing circuit 102.
Is output as a pulse every predetermined period. Frequency divider 1
The pulse from 02 drives the light projecting element 11 via the drive circuit 103 to emit light. When the projection light from the light projecting element 11 is reflected by the object to be detected and enters the light receiving element 9, the light receiving element 9 outputs a light receiving signal. The light reception signal from the light receiving element 9 is supplied to the comparison circuit 105 via the amplification circuit 104 and compared with the reference voltage. When the light reception signal exceeds the reference voltage, the comparison circuit 105 outputs a high level light reception pulse. It The received light pulse from the comparison circuit 105 is supplied to the display circuit 107, the detection output indicator lamp is turned on in the display circuit 107, and the received light pulse from the comparison circuit 105 is detected (counted) in the detection circuit 106. The detection circuit 106 outputs an output to the output circuit 108 when the received light pulses are continuously counted up to a predetermined number, and clears the count value if the received light pulses are discontinuous or if they are not continuously counted up to the predetermined number. It is configured to remove noise and the like due to ambient light. When the photoelectric switch is set, when the switch 4 is pressed to activate the switch circuit 108, the light projecting chip 13 enclosed in the light receiving element 9 emits light, visible light is emitted from the light receiving section 6, and the lighting circuit 109 operates. Then, continuous visible light is output from the light projecting element 11. If the drive circuit 103 is directly driven by the switch circuit 108 as shown by the dotted line, the lighting circuit 109 is not necessary.

FIG. 4 is a side view of an essential part of a second embodiment of the present invention, in which the same reference numerals as those in FIG. 1 denote the same parts or the same parts. In this embodiment, a visible light emitting element 14 is provided inside the light receiving section 6, and the visible light emitting element 14 and the light receiving element 9 are provided.
A half mirror 15 is provided between and. Visible light emitted from the visible light emitting element 14 is reflected by the half mirror 15, passes through the lens 10, and is emitted from the light receiving unit 6.
The reflected light from the detected object when detecting the detected object passes through the lens 10 in parallel with the light receiving axis A, further passes through the half mirror 15, and is incident on the light receiving element 9.

FIG. 5 is a side view of the essential portions of a third embodiment of the present invention, in which the same reference numerals as those in FIG. 4 denote the same parts or the same parts. In this embodiment, the visible light emitting device 14 shown in FIG.
Instead of this, visible light is made incident on the inside of the light receiving section 6 from the stable operation indicator lamp 2 through a light guide tube 16 such as a transparent plastic tube. FIG. 6 shows a fourth embodiment of the present invention, which has a completely different construction from that shown in FIGS. That is, the visible light emitted from the light receiving element (having a function of emitting visible light) 9 and the light projecting element 11 provided on the front surface of the main body case 1 is the optical fibers 17a, 17
The metal fittings 19a, 19 of the sensor jig 18 are guided by b.
The light is emitted from the tip of the fiber fixed by b, intersects at the point C along the light receiving axis A and the light projecting axis B, and forms the operation region (hatched portion) of the detected object D. This operating area is the wall surface E
It is desirable to set the positions slightly apart from each other, and this can be easily performed by adjusting the mounting relationship and positions of the sensor jig 18 and the mounting brackets 19a and 19b.

[0012]

According to the present invention, visible light is emitted also from the light receiving portion at the time of setting, and the intersection of this visible light and the visible light emitted from the light projecting portion can be easily visually recognized as the detection operation area. Therefore, the setting work of the photoelectric switch becomes easy.

[Brief description of drawings]

FIG. 1 is a side sectional view of an essential part of an embodiment of the present invention.

FIG. 2 is an enlarged side sectional view of the light receiving element in FIG.

FIG. 3 is a block diagram of an electric circuit of a photoelectric switch according to an embodiment of the present invention.

FIG. 4 is a side sectional view of the essential part of the second embodiment of the present invention.

FIG. 5 is a side sectional view showing an essential part of a third embodiment of the present invention.

FIG. 6 is a schematic configuration diagram of a fourth embodiment of the present invention.

[Explanation of symbols]

 1 Case 2 Stable operation indicator 4 Switch 6 Light receiving part 7 Light emitting part 9 Light receiving element 13 Light emitting chip 14 Visible light emitting element 15 Half mirror 16 Light guide tube 17a Optical fiber 17b Optical fiber A Light receiving axis B Light emitting axis

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location H03K 17/78 P 9383-5J

Claims (7)

[Claims] 1. A light projecting portion and a light receiving portion are provided on the front surface of a case, and a light projecting axis from the light projecting portion and a light receiving axis to the light receiving portion intersect at the front of the case, and the crossing range is covered. In a reflection type photoelectric switch that detects the presence or absence of an object to be detected when a detection object passes through, the projection unit is provided with visible light projection means for emitting visible light parallel to the projection axis, and the light reception unit is provided with the reception axis. A reflection type photoelectric switch characterized in that it is provided with a visible light projecting means for emitting visible light parallel to. 2. A light-receiving element of a light-receiving unit according to claim 1, wherein a light-emitting chip capable of emitting visible light is enclosed, and an optical axis from the light-emitting chip is aligned with a light-receiving axis. Reflective photoelectric switch. 3. The half according to claim 1, wherein a visible light emitting element is provided at a position different from the light receiving element in the light receiving portion, and the visible light emitted from the visible light emitting element is provided on the front surface of the light receiving element. A reflection type photoelectric switch characterized in that the visible light axis is made to coincide with the light receiving axis by being reflected by a mirror. 4. The device according to claim 1, wherein visible light emitted from a stable operation indicator lamp visible from the outside of the case is incident on the light receiving portion through a light guide tube and reflected by a half mirror. A reflective photoelectric switch characterized by aligning the visible light axis with the light receiving axis. 5. The optical system according to claim 1, wherein the visible light from the light projecting portion and the visible light from the light receiving portion are respectively led out by optical fibers, and the ends of the both optical fibers are fixed so that the both visible light intersect. A reflective photoelectric switch characterized by 6. The reflection type photoelectric switch according to claim 1, wherein the visible light from the light projecting portion and the visible light from the light receiving portion have different colors. 7. A light projecting portion and a light receiving portion are provided on the front surface of the case, and a light projecting axis from the light projecting portion and a light receiving axis to the light receiving portion intersect at the front of the case. In a reflective photoelectric switch that detects the presence or absence of an object to be detected when a detection object passes through, the light projection section is provided with visible light projection means for emitting visible light parallel to the projection axis, and the light reception section is provided with a light reception axis. And a switch for turning on / off each of the visible light projecting means of the light projecting unit and the visible light projecting unit at the same time.