JPH0541146A - Method and jig for adjusting optical axis of photoelectric switch - Google Patents

Abstract

PURPOSE:To obtain a method for adjusting an optical axis of a photoelectric switch securely and easily without depending on sensation of a person, and obtain a jig to be used for executing this method. CONSTITUTION:An opaque sheet 1 having a through hole 2, diameter of which is smaller than an aperture of a lens of a photoelectric switch (projector or light receiver), is put on the lens installation surface of a photoelectric switch (projector or light receiver) 3. Optical axis is adjusted under the condition that the center position of the through hole 2 is aligned with the center position of the lens, and the photoelectric switch (projector or light receiver) 3 is set under this condition.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of adjusting an optical axis of a transmission type or a retroreflective type photoelectric switch and an optical axis adjusting jig used for carrying out the method.

[0002]

2. Description of the Related Art A transmissive photoelectric switch is composed of a light emitter and a light receiver, and detects the presence of an object to be detected by a change in the amount of light received by the light receiver when the object to be detected passes through the path of light emitted from the light emitter. .. Therefore, it is necessary to install the photoelectric switch so that the light emitted from the light projector is accurately transmitted to the light receiver, that is, the optical axis is adjusted. Therefore, conventionally, as shown in FIG. 20, a projector 101 and a receiver 102 are installed with their lenses 103 and 104 facing each other. First, the projector 101 is swung vertically, horizontally and in a stable state. Then, the optical receiver 102 is swung up, down, left and right to fix the optical axis at a position where it seems to operate stably.

The retroreflective photoelectric switch is composed of a projector also serving as a light receiver and a reflector plate, and receives light when an object to be detected passes through an optical path in which light emitted from the light projector hits the reflector plate and is reflected to enter the light receiver. The presence of an object to be detected is detected by a change in the amount of light received by the vessel. The optical axis adjustment in this case is performed by the reflector plate 105 as shown in FIG.
The reflecting surface of the projector is installed so as to face the lens mounting surface of the projector 106, and stable operation can be performed by swinging the projector 106 vertically and horizontally, that is, the light emitted from the projector hits the reflector plate and is reflected accurately. This is done by fixing the light incident on the light receiver.

[0004]

Since such conventional optical axis adjustment is performed by swinging the photoelectric switch depending on the sense of the individual, it varies depending on the photoelectric switch. Especially, even if there is some vibration or dust adheres to the lens surface, the photoelectric switch operates reliably, so that the optical axis adjustment to the so-called marginal detection state varies depending on the photoelectric switch. There is a problem that the photoelectric switch does not function sufficiently.

In view of the above-mentioned problems, an object of the present invention is to implement an optical axis adjusting method for a photoelectric switch and an optical axis adjusting method which can perform optical axis adjustment in a detection state with a margin very easily and surely. It is to provide an optical axis adjusting jig to be used.

[0006]

According to the present invention, in a transmission type photoelectric switch in which a light emitter and a light receiver are installed with their lens mounting surfaces facing each other, the lens mounting surface of at least one of the light emitter and the light receiving device is aforesaid. An opaque sheet having a through hole smaller than the diameter of the lens is covered so that the center position of the through hole and the center position of the lens are aligned, and the light emitted from the projector is located at the lens center position of the light receiver or the center position of the through hole of the opaque sheet. A retroreflective photoelectric switch that fixes the transmitter and the receiver in the state of being incident on the lens, and has a reflector plate installed in front of the lens mounting surface of the projector that also functions as the receiver, with its reflecting surface facing the lens mounting surface. At
An opaque sheet having a through hole smaller than the aperture of the lens of the projector is provided on at least one of the projector and the reflecting surface of the reflector plate so that the central position of the through hole and the central position of the lens are aligned, and the light emitted from the projector is reflected. The projector and the reflector are fixed in a state where they are reflected by the plate and are incident on the center of the lens of the projector or the center of the through hole of the opaque sheet.

The optical axis adjusting jig of the photoelectric switch used for carrying out the method of the above-mentioned claim 1 is covered on the mounting surface of the lens of the projector or the receiver and has a through hole smaller than the diameter of the lens. The opaque sheet has a protruding piece or a bent extension portion on its upper side. Further, the folding extension of this opaque sheet is provided with a shift-prevention hole that is fitted into a protrusion provided on the upper surface of the case of the sender or the receiver, and is further bent at the cable drawing surface of the case of the sender or the receiver. The bent portion is provided with a notch portion for inserting and holding the cable. Furthermore, in the optical axis adjusting jig of a photoelectric switch used for carrying out the method according to claim 2, the sheet covered by the reflector plate is an opaque sheet having a through hole smaller than the diameter of the lens of the projector or the receiver. Also, this opaque sheet has a protruding piece on its upper side.

[0008]

According to the present invention, an opaque sheet having a through hole smaller than the lens aperture is covered on the lens mounting surface of the projector or the receiver or on the reflecting surface of the reflector plate to adjust the optical axis, that is, the projector and the receiver or the reflector plate. Setting. In this case, the light emitted from the projector through the lens is strongest in the central portion and becomes weaker as it spreads to the outer periphery. In this invention, only the strong light in the center of the optical axis is transmitted while the weak light in the outer peripheral portion is blindfolded by the opaque sheet, and the optical axis is adjusted by using this light, so that the light amount lower than that in normal use is used. But more stable optical axis adjustment is possible.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a front view showing a state in which an opaque sheet used for carrying out the method of the present invention in a transmission type photoelectric switch is attached to a projector or a light receiver of the photoelectric switch, and FIG. 2 is a side view of the state. Is. The opaque sheet 1 has the same size or a similar size capable of covering the lens mounting surface of the photoelectric switch (light transmitter or light receiver) 3, and has a through hole 2 at the center thereof which is smaller than the lens aperture. FIG. 3 shows a state in which the optical axis of the photoelectric switch 3 is adjusted using the opaque sheet 1. In the figure, the opaque sheet 1 is attached to the surface of the photoelectric switch (light projector) 3 on which the lens 4 is mounted, with the center of the through hole 2 and the center of the lens 4 aligned. Similarly, the opaque sheet 1 is attached to the photoelectric switch (light receiver) 3, and both photoelectric switches (light projector and light receiver) 3 are installed so that both opaque sheets 1 face each other.
In this state, light is emitted from the projector, both photoelectric switches 3 are swung vertically and horizontally, and both photoelectric switches 3 are fixed when the optical axis 5 emitted from the through hole 2 is incident on the opposite through hole 2. To do. FIG. 4 shows a state in which the opaque sheet 1 is attached only to the photoelectric switch (projector) 3 on the projecting side to adjust the optical axis, and FIG. The state where the optical axis is adjusted by sticking only it is shown.

FIG. 6 is a front view showing a state in which different opaque sheets used for carrying out the method of the present invention are mounted on a projector or a light receiver of a photoelectric switch, and FIG. 7 is a side view of the state. The feature of the opaque sheet 11 is that the protruding pieces 15 are provided at the upper corners of the opaque sheet 1 shown in FIG. After the optical axis adjustment, the photoelectric switch is in the detection operation state, so that the attached opaque sheet must be peeled off. However, if the protruding piece 15 is pinched and peeled off, the opaque sheet can be peeled off very easily. The method of adjusting the optical axis is exactly the same as that described with reference to FIGS.

FIG. 8 is a front view showing a state in which a different opaque sheet used for carrying out the method of the present invention is attached to a projector or a light receiver of a photoelectric switch, and FIG. 9 is a side view of the state. The feature of this opaque sheet 21 is that a bent extension 24 is formed from the upper side of the opaque sheet 1 shown in FIG.
Is provided, and the bent extension portion 24 is formed so as to be attached to the upper surface of the case of the photoelectric switch 23. This is effective in preventing the shift of the opaque sheet 21 (the shift between the center of the through hole 22 and the center of the lens).

FIG. 10 is a front view showing a state in which a different opaque sheet used for carrying out the method of the present invention is attached to the projector or the receiver of the photoelectric switch, and FIG.
Is a side view of the state. The opaque sheet 31 is provided with a shift-preventing hole 35 in the bent extension portion 34, and the shift-preventing hole 35 is fitted into a protrusion 36 provided on the upper surface of the case of the photoelectric switch 33. The feature of the opaque sheet 31 is that the opaque sheet 21 shown in FIGS.
In addition to the features described above, the opaque sheet 31 can be easily removed.

FIG. 12 is a front view showing a state in which a different opaque sheet used to carry out the method of the present invention is attached to the projector or the receiver of the photoelectric switch, and FIG.
Is a side view of the state. The opaque sheet 42 further extends the bent extension 34 in FIGS. 8 and 9, and is further bent at the upper side of the upper surface of the cable 46 drawing surface of the case of the photoelectric switch 43, and the cut portion 4 is formed in the bent portion 45.
7 is provided to insert and hold the cutout portion 47 in the cable 46 (see FIG. 14). This opaque sheet 4
2 further emphasizes the features of the opaque sheet 31 shown in FIGS. 10 and 11 (prevention of displacement and easy removal).

FIG. 15 is a front view of an opaque sheet used for implementing the present invention in a retroreflective photoelectric switch, and FIG. 16 is a side view showing a state where the opaque sheet shown in FIG. 15 is attached to a reflector plate. This opaque sheet 5
Reference numeral 1 has the same size or a similar size capable of covering the reflecting surface of the reflector plate 55, and has a through hole 52 smaller than the lens aperture in the center thereof. This opaque sheet 5
When the optical axis of the reflection type photoelectric switch 53 is adjusted using 1, the opaque sheet 51 is attached to the reflection surface of the reflector plate 55 having the attachment piece 54, as shown in FIG.
A reflective photoelectric switch (projector) 53 is installed at a position facing the opaque sheet 51, and the reflective photoelectric switch 53 is vertically and horizontally aligned so that the center of the through hole 52 and the lens center of the reflective photoelectric switch 53 are aligned. Shake it.

FIG. 18 is a front view of a different opaque sheet used for implementing the present invention in a retroreflective photoelectric switch, and FIG. 19 is a side view of the reflector plate with the opaque sheet shown in FIG. The opaque sheet 61 is characterized in that the protruding pieces 63 are provided at the upper corners of the opaque sheet 51 shown in FIG. 15, which is convenient when the opaque sheet 61 attached to the reflector plate 65 is removed.

[0016]

In a photoelectric switch having a normal aperture, an opaque sheet having a through hole is attached to the lens mounting surface of the projector of the photoelectric switch with the center of the through hole and the center of the lens aligned with each other. When the optical axis is adjusted by projecting light from, the amount of light emitted is about half when the through hole of the opaque sheet is a small hole such as 4 mmΦ, the parallel movement characteristic is narrow, and the detection distance is about 70
Fell to%. When the photoelectric switch is set in this state, the opaque sheet is peeled off and the photoelectric switch is used, the light amount doubles and the detection state can be set with a margin, and malfunction does not occur due to dust adhesion or some vibration. ..

[Brief description of drawings]

FIG. 1 is a front view showing a state in which an opaque sheet used for implementing the method of the present invention in a transmission type photoelectric switch is attached to a projector or a receiver of the photoelectric switch.

FIG. 2 is a side view of FIG.

FIG. 3 is a perspective view showing a state in which an opaque sheet is attached to both the photoelectric switch on the light emitting side and the photoelectric switch on the light receiving side to adjust the optical axis.

FIG. 4 is a perspective view showing a state in which an opaque sheet is attached only to the photoelectric switch on the light projecting side to adjust the optical axis.

FIG. 5 is a perspective view showing a state in which an opaque sheet is attached only to the photoelectric switch on the light receiving side to adjust the optical axis.

FIG. 6 is a front view of a different opaque sheet used to carry out the method of the present invention, mounted on the projector or the receiver of the photoelectric switch.

FIG. 7 is a side view showing a state where the opaque sheet shown in FIG. 6 is attached to the lens mounting surface of the photoelectric switch.

FIG. 8 is a front view showing a state in which a different opaque sheet used to carry out the method of the present invention is attached to a projector or a receiver of a photoelectric switch.

9 is a side view showing a state in which the opaque sheet shown in FIG. 8 is attached to the lens mounting surface of the photoelectric switch.

FIG. 10 is a front view showing a state in which a different opaque sheet used to carry out the method of the present invention is attached to a projector or a receiver of a photoelectric switch.

FIG. 11 is a side view showing a state where the opaque sheet shown in FIG. 10 is attached to the lens mounting surface of the photoelectric switch.

FIG. 12 is a front view in which a different opaque sheet used to carry out the method of the present invention is attached to a projector or a receiver of a photoelectric switch.

FIG. 13 is a side view showing a state in which the opaque sheet shown in FIG. 12 is attached to the lens mounting surface of the photoelectric switch.

FIG. 14 is a view on arrow P of FIG.

FIG. 15 is a front view of an opaque sheet used to implement the present invention in a retroreflective photoelectric switch.

16 is a side view showing a state where the opaque sheet shown in FIG. 15 is attached to the reflecting surface of the reflector plate.

FIG. 17 is a perspective view showing a state where the opaque sheet in the state shown in FIG. 16 is opposed to the lens mounting surface of the reflective photoelectric switch case to adjust the optical axis.

FIG. 18 is a front view of a different opaque sheet used to implement the invention in a retroreflective photoelectric switch.

FIG. 19 is a side view showing a state where the opaque sheet shown in FIG. 18 is attached to the reflecting surface of the reflector plate.

FIG. 20 is a perspective view showing a conventional optical axis adjusting method in a transmission type photoelectric switch.

FIG. 21 is a perspective view showing a conventional optical axis adjusting method in a reflective photoelectric switch.

[Explanation of symbols]

 1 Opaque Sheet 2 Through Hole 3 Photoelectric Switch (Emitter or Light Receiver) 4 Lens 5 Optical Axis 11 Opaque Sheet 12 Through Hole 13 Photoelectric Switch (Emitter or Light Receiver) 15 Projection Piece 21 Opaque Sheet 22 Through Hole 23 Photoelectric Switch (Emitter or Light Emitter) 24) Bending extension 31 Opaque sheet 32 Through hole 33 Photoelectric switch (projector or receiver) 34 Bending extension 35 Misalignment hole 36 Protrusion 41 Opaque sheet 42 Through hole 43 Photoelectric switch (projector or receiver) 44 Bending extension 45 Bending 46 Cable 47 Notch 51 Opaque sheet 52 Through hole 54 Mounting piece 53 Photoelectric switch (light projector) 55 Reflector plate 61 Opaque sheet 62 Through hole 63 Projecting piece 64 Mounting piece 65 Reflector plate

Claims (9)

[Claims] 1. A transmission type photoelectric switch in which a light emitter and a light receiver are installed with their lens mounting surfaces facing each other, and a through hole smaller than the diameter of the lens is formed in at least one lens mounting surface of the light emitter and the light receiver. An opaque sheet having
The center position of the through hole and the center position of the lens are covered together, and the light emitter and the light receiver are fixed in a state where the light emitted from the light emitter enters the lens center position of the light receiver or the center position of the through hole of the opaque sheet. A method for adjusting an optical axis of a photoelectric switch, comprising: 2. A recursive reflection type photoelectric switch in which a reflector plate is installed in front of a lens mounting surface of a projector also serving as a light receiver so that the reflecting surface of the reflector plate faces the lens mounting surface. An opaque sheet having a through hole smaller than the aperture of the lens of the projector is covered on at least one of the positions of the through hole and the center position of the lens so that the light emitted from the projector hits the reflector plate and is reflected to the lens of the projector. A method of adjusting an optical axis of a photoelectric switch, characterized in that a light projector and a reflector are fixed in a state of being incident on a central position or a central position of a through hole of an opaque sheet. 3. The sheet used for carrying out the method according to claim 1 or 2 and covering the mounting surface of the lens of the projector or the receiver is an opaque sheet having a through hole smaller than the aperture of the lens. An optical axis adjustment jig for a photoelectric switch. 4. The optical axis adjusting jig for a photoelectric switch according to claim 3, wherein the opaque sheet has a protruding piece on its upper side. 5. The optical axis adjusting jig for a photoelectric switch according to claim 3, wherein the opaque sheet is provided with a bent extension on its upper side. 6. A fold-extending portion of the opaque sheet according to claim 5, wherein the fold-extending portion is provided with a shift-preventing hole fitted into a protrusion provided on the upper surface of the case of the projector or the receiver. Optical axis adjustment jig for photoelectric switch. 7. The foldable extension of the opaque sheet further comprises a foldable portion which is foldable at a cable lead-out surface of a case of the projector or the receiver, the foldable portion being the foldable portion. An optical axis adjusting jig for a photoelectric switch, which is provided with a notch for inserting and holding a cable. 8. An optoelectronic sheet used to carry out the method according to claim 2, wherein the sheet overlying the reflector plate is an opaque sheet having a through hole smaller than the aperture of the lens of the projector or the receiver. Switch optical axis adjustment jig. 9. The optical axis adjusting jig for a photoelectric switch according to claim 8, wherein the opaque sheet has a protruding piece on its upper side.