JPH06169249A - Optical switch - Google Patents

Abstract

PURPOSE:To attain thread connection not requiring precision working for alignment by reflecting a light of an LED from other side so as to change a light receiving quantity of a photo transistor(TR) thereby changing an output level of a signal processing circuit for the purpose of switching. CONSTITUTION:Plural optical sensors 14a-14c are made up of a transparent member, light emitting diodes LED 15a-15c arranged to one side of the transparent member closely, and light receiving photo TRs 16a-16c arranged closely or integrally. An oscillation circuit 18 lights up the LED 15a-15c at a prescribed period. Furthermore, signal processing circuits eliminate a background component in signals from the photo TRs 16a-16c. Then the light of the LED 15a-15c is reflected by a reflector 30 arranged to the other side of the transparent member 10 to increase the light receiving quantity of the photo TRs 16a-16c. An output level of the output signal processing circuit 20a-20c is changed by the increased luminous quantity and a change in the output level is used for a switch signal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to driving a switch fixed to, for example, a circuit board arranged in a container,
The present invention relates to an optical switch in which the switch is turned on / off from the outside of the container in a non-contact manner.

[0002]

2. Description of the Related Art FIGS. 1 (a) and 1 (b) are schematic views of an essential part of an apparatus for turning on / off a switch provided on a circuit board in a container from outside the container. In the figure, 1 is a flameproof container, 2 is a lid of the container 1, and these are fixed by bolts 3. Reference numeral 4 denotes a circuit board arranged in the container, and a switch 5 is attached to the circuit board. 6
Is a push button provided on the lid 1 side together with the spring 7, one end of which is exposed on the outer surface of the lid. In the above configuration, the push button 6 is normally restricted to the lid 2 side by the spring 7, and by pushing this by hand, the switch 5 is pushed by the tip thereof to perform switching.

[0003]

By the way, when the above-mentioned container is used as a pressure-proof explosion-proof applicable to hydrogen, acetylene, etc., the gap between the lid and the push button must be precisely processed so that there is no flame escape and the lid is The container and the container need to be connected by a screw structure, but in the above-mentioned conventional example, a plurality of holes are formed in the lid, a push button is attached, and this is pressed from the outside of the lid, which requires precision processing. In addition, there is a problem that it is difficult to align the hole and the push button with a screw connection structure for the lid and the container. The present invention has been made to solve the above-mentioned problems of the prior art, and an object of the present invention is to provide an optical switch having a configuration capable of screw connection between a lid and a container without requiring precision processing for alignment.

[0004]

In order to solve the above-mentioned problems, the present invention provides a transparent member and a light-emitting LED and a light-receiving phototransistor which are arranged close to one side of the transparent member so as to be close to or integrated with each other. A plurality of configured optical sensors, an oscillating circuit for lighting the LED at a constant cycle, and a signal processing circuit for removing a background component of the signal from the phototransistor are provided, It is characterized in that the light is reflected from the other side of the transparent member to change the amount of light received by the phototransistor, and the output level of the signal processing circuit is changed to perform switching.

[0005]

The LED lights up at a constant cycle by the oscillation circuit. The phototransistor for light reception receives the light of the LED partially reflected by the transparent member on the front surface and the external light and outputs a signal corresponding to the light amount, but the output level of the signal processing circuit does not change at the level of this light amount. Then, when a reflecting member is arranged on the other side of the transparent member and the light from the LED is reflected to the phototransistor side for a predetermined time, the amount of light incident on the phototransistor increases and the output level of the output signal processing circuit changes. . The change in the output level is used as a switch signal.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic view of the essential parts of an embodiment of an optical switch according to the present invention. In the figure, 1a is a container having a screw 1b formed at its cylindrical end, 2a is a lid having a transparent member (glass) 10 provided at its center, and is screwed into the screw 1b of the container by the screw 2b. . 11 is a container 1a
And an O-ring that hermetically seals the lid 2a. It should be noted that these are formed in a flameproof structure.

Reference numerals 14a, 14b and 14c denote optical sensors arranged in the container and arranged in proximity to the glass 10. A light emitting diode (hereinafter simply referred to as LED) 15 and a light receiving photodiode (hereinafter simply referred to as PD) 16 are in close proximity. Alternatively, it is integrally formed. 17 is an optical sensor 14 (a, b, c)
Power source, 18 is an oscillating circuit for lighting the LED of each optical sensor at a constant cycle (for example, 0.1 seconds), 19a, 19b
Is a gate circuit arranged between the oscillation circuit 18 and the LEDs of the optical sensors 14a and 14b.

Reference numeral 20 is a signal processing circuit, 21 is a comparator, and the signal level of the signal processing circuit 20 is a bias circuit 22.
a, 22b, and 22c are compared with the setting signal determined by
An input / output port 23 inputs a signal from the comparator and outputs the signal to each unit. This input / output port 2
The signal from 3 is, for example, the CPU 25 or the LEDs 17a, 17
b, 17c (these LEDs 16e, 16
Although f and 16g are located behind the I / O port in the figure, they are actually located at positions where the lighting can be confirmed through the glass 10.

The operation of each part and the signal waveform in the above-mentioned configuration will be described with reference to FIGS. In addition, here, the signal of the optical sensor 14c is transmitted to other optical sensors 14a, 14c.
The case where it is used as the drive switch of b will be described.
In FIG. 1, the LED 15c of the optical sensor 14c is pulse-lighted on the basis of the output of the oscillation circuit 18 in a cycle as shown in FIG. 2a. PD16c placed close to this LED
Always outputs a pulse signal as shown in FIG. 2b _{−1 under} the influence of the light of the LED 15c reflected by the window glass 10 and the external light.

Next, when a reflector (which may be, for example, a finger) 30 is placed close to or in contact with the front surface of the LED 15c (in front of the glass 10), the amount of light reflected by this reflector increases, so the output of the PD 16c. The level will look like Figure 2b _-2 . These signals are input to the signal processing circuit 20c, output to the comparator 21c, and compared with the set voltage of the bias circuit 22c. In this case, this set voltage is set higher than the voltage level of only the light of the LED 15c reflected by the window glass and the external light, and lower than the level when the amount of light reflected by the reflector 30 is added. As a result, the output of the comparator 21c becomes high level only when the reflector 30 is arranged. The level of b _-3 shows the level when the reflector 30 is removed.

The signal processing circuit 20 has a built-in AC amplifier, bandpass filter (not shown), etc., for example.
As shown in g (a), only the pulsed signal (b) obtained by removing the direct current component from the signal containing the direct current component (background) is passed and the peak voltage is output as a voltage signal. Therefore, the output of the signal processing circuit 20c becomes a low level (Va) shown in FIG. 3c- ₁ or a high level (Vb) shown in FIG. 3c- ₂ . This high level signal is compared with the setting signal (Vr) of the comparator 21c,
When it is larger than this setting signal, the output of the comparator 21c becomes high level as shown in FIG. This output is output to the CPU 25 through the I / O port 23, and the CPU 25 outputs the reflected light (high level) from the reflector for a predetermined time (t ₁ ... 5
(Second) If it is not held continuously, it is determined to be a noise signal.

Next, when the CPU 25 determines that the optical switch 14c is turned on, the signal is transmitted via the I / O port 23 to the gate circuits 19a and 19b and the LED 1.
7c. This signal (the time indicated by t ₂ in FIG. 2f) turns on the LED 16e.
It is confirmed that a and 14b are ready for start-up (note that the signals sent to the gate circuits 19a and 19b are OFF signals of these switches when the optical switches 14a and 14b have already been started, Next, the reflector is LED1
The same state is maintained until it is placed before 5c).

[0013] The optical switch 14a, the 14b becomes active state LEDs 15a, 15b is pulsed light in the same period as FIG. 2 (a), PD16a, PD16b Figure 2b _-1
The signal processing circuit outputs a signal as shown in FIG. 2c _-1 . Next, for example, a reflector (such as a finger) may be provided on the front surface of the LED 15a (in front of the glass 10) 3
When 0s are arranged close to or in contact with each other, the amount of light reflected by this reflector increases, so the output level of the PD 16a is shown in FIG.
It becomes something like _-2 . These signals are input to the signal processing circuit, output to the comparator 21a, and compared with the set voltage of the bias circuit 22a. This set voltage is higher than the voltage level of the light of the LED 15a reflected by the window glass and the external light. , It is set lower than the level of the amount of light reflected by the reflector.

As a result, the output of the comparator 21c becomes high level only when the reflector is arranged. Note that the signal processing circuit 20 has, for example, an AC amplifier, a bandpass filter, etc. built therein as described above, and passes only the pulsed signal in the oscillation circuit as shown in FIGS. 2G to 2C. As shown in FIG. 2c, it is output as a voltage signal holding the peak voltage. This signal is also output to the CPU 25 via the I / O port 23, but the CPU judges that it is a noise signal when the reflected light from the reflector is not retained for a predetermined time (for example, 0.5 seconds). Is configured. The same operation is performed when a reflector is arranged on the front surface of the optical sensor 14b. Although the number of optical sensors is three in the above embodiment, the number of optical sensors may be one or three or more. Further, in the embodiment, the optical sensor 15c and the gate circuits 19a, 1a
Although 9b is used as a drive switch for another optical sensor, it is not limited to such a use method. For example, the gate circuit can be removed and all photosensors can be used as independent switches.

FIG. 3 to FIG. 6 are main part configuration diagrams showing another embodiment of the present invention. In these figures, the same elements as those in FIG. 1 are designated by the same reference numerals, and overlapping description will be omitted. In FIG. 3, a cover plate 35 having a partition plate 36 is formed on the lid 2a so as to cover the front surface of the glass 10, a reflector 30 is provided on the cover plate 35 so as to face the optical sensor 14, and a spring 7 is provided for the reflector 30. The position is regulated. According to the above configuration, when the reflector 30 is pressed to approach the optical sensor 14, the amount of light received by the PD changes. The shield plate 35 removes the influence of external light, and the partition plate 36 is the LED of one of the optical sensors.
It functions so that the change in the light amount of does not affect other optical sensors.

In FIG. 4, only the PD is used as the structure of the optical sensor 14, and the PD is irradiated with a pulse signal of a predetermined light amount from the outside of the glass 10 by using the remote controller 40. . The remote controller 40 is composed of a switch 41, a signal processing circuit 42, and an LED 43. According to the above configuration, the remote controller 40 is required, but the configuration of the optical sensor can be simplified and the contents of signals from the remote controller can be enriched.

FIG. 5 shows another embodiment of the optical sensor 14. In this embodiment, one end of the optical sensor 14 'is exposed to the outside of the explosion-proof container 1a, and the outer peripheral portion B is bonded or screwed. It is fixed by such means. 15 is L
ED and 16 are PDs, and the light emitted from the LED irradiates the PD 16 via the optical fiber 45, but the partition plate 36a is arranged by cutting the light. Light is switched to the PD side by moving the partition plate in the direction of the arrow. According to the above configuration, reliable switch operation is possible.

[0018]

As described above in detail with reference to the embodiments, according to the present invention, the light of the LED is reflected from the other side of the transparent member to change the amount of light received by the phototransistor, and the output of the signal processing circuit is changed. Since switching is performed by changing the level, it is possible to realize an optical switch that does not require precision processing for alignment and enables screw connection between the lid and the container.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a main part of an optical switch showing an embodiment of the present invention.

FIG. 2 is a waveform diagram showing the operation of FIG.

FIG. 3 is a main part configuration diagram showing another embodiment.

FIG. 4 is a main part configuration diagram showing another embodiment.

FIG. 5 is a configuration diagram of main parts showing another embodiment.

FIG. 6 is a configuration diagram showing a conventional example.

[Explanation of symbols]

 1a Container 2a Lid 10 Transparent member 11 O-ring 14 Optical sensor 15 Light emitting diode (LED) 16 Phototransistor (PD) 17 Power supply 18 Oscillation circuit 19 Gate circuit 20 Signal processing circuit 21 Comparator 22 Bias circuit 23 Input / output (I / O) Port 25 CPU 30 Reflector

Claims (1)

[Claims] 1. A transparent member, a plurality of photosensors arranged in proximity to one side of the transparent member and having a light emitting LED and a light receiving phototransistor in close proximity or integrally with each other; And a signal processing circuit for removing a background component of the signal from the phototransistor, and reflects the light of the LED from the other side of the transparent member to generate a light from the phototransistor. An optical switch characterized in that switching is performed by changing an amount of received light and changing an output level of the signal processing circuit.