JPH0648886Y2 - Photo-interrupter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a photo interrupter comprising a light emitting element and a light receiving element, and detecting the interruption or opening of the optical path from the light emitting element to the light receiving element. is there.

[Conventional technology]

Conventionally, the photo interrupter is generally configured as shown in FIG. That is, the photo interrupter 1 includes a light emitting element 2 and a light receiving element 3 which are arranged to face each other on a pair of substrates.
Is included. The light emitting element 2 is connected between a power supply connection lead terminal 4 to which a constant current is supplied from a power source (not shown) and a ground side connection lead terminal 5 so as to drive and emit light. Element 3 is
For example, in the case of a phototransistor, its collector is connected to the power supply connection lead terminal 4 through the resistor 6 and directly connected to the signal extraction connection lead terminal 7, and its emitter is directly connected to the ground side. It is connected to the lead terminal 5.

According to the photo interrupter 1 thus configured,
When the optical path from the light emitting element 2 to the light receiving element 3 is open, the light from the light emitting element 2 is incident on the light receiving element 3 and thereby the collector-emitter of the light receiving element 3 is turned on. Therefore, the voltage of the signal lead-out connection lead terminal 7 is connected to the ground-side connection lead terminal 5, and is almost 0 volt, that is, L level.

Here, if the optical path is blocked by, for example, a sheet to be detected, the light from the light emitting element 2 does not enter the light receiving element 3, so the collector-emitter of the phototransistor, which is the light receiving element 3, is turned off. Therefore, the signal lead-out connection lead terminal 7 is almost equal to the voltage of the power supply connection lead terminal 4 through the resistor 6, that is, the voltage of the driving power supply for the light emitting element 2 and the light receiving element 3, that is, at the H level.

[Problems to be solved by the invention]

As described above, the conventional photo interrupter 1 processes the L-level or H-level output signal output from the signal extraction connection lead terminal 4 by opening and blocking the optical path by an appropriate control circuit or the like. , Various controls are performed.

However, the photo interrupter 1 having such a configuration
, There are two states of whether the optical path from the light emitting element 2 to the light receiving element 3 is blocked or open depending on whether the output signal of the signal lead-out connection lead terminal 4 is L level or H level. It was impossible to perform complicated control because only discrimination was performed.

In view of the above points, the present invention has a relatively small configuration,
It is an object of the present invention to provide a photo interrupter that can be controlled in multiple stages.

[Means and Actions for Solving Problems]

To achieve the above object, in the present invention, two pairs of light emitting elements, preferably LEDs, and light receiving elements, preferably phototransistors or photodiodes, which are arranged to face each other, are provided for power supply, signal extraction and ground. Each of the light emitting elements is driven and emitted by being connected between the power supply connection lead section and the ground side connection lead section. In the photointerrupter which is driven by being connected between the power supply connection lead portion and the earth side connection lead portion, the output of each light receiving element is connected to the signal extraction connection lead portion through a resistor. In addition, a current limiting resistor is connected in series with each of the light receiving elements, and the signal extraction is performed according to the operating states of the light emitting element and the light receiving element. H level in use connecting leads, and configured to obtain the L level and the output signals of an intermediate level.

According to this invention, when both optical paths are blocked, light does not enter the light receiving element, and therefore both the light receiving elements output L level or H level signals, but both optical paths are open. In this case, the light receiving element outputs an inverted H level signal or L level signal. Also,
When only one of the optical paths is cut off, the H-level and L-level signals are output from the two light receiving elements.

Therefore, a signal of H level, L level or an intermediate level is output to the signal extraction connection lead portion of the photo interrupter based on the open / closed state of each optical path.
As a result, the open / closed state of each optical path can be detected by the voltage of the signal lead-out connection lead portion. At that time, by appropriately selecting the resistance value of the resistor connected to the output of each light receiving element, it is possible to determine which optical path is blocked or open, and the two pairs of light emitting elements and Since the light receiving element is housed in one case, it is configured to be relatively small, and further, since only three pairs of connecting lead portions to the light emitting element and the light receiving element are required,
Wiring can be simplified and assembly costs can be reduced.

Here, each light receiving element is composed of a phototransistor, each collector of the phototransistor is connected to a power supply connection lead portion and a signal extraction connection lead portion via a resistor, and the emitter is directly connected to a ground side connection lead. In the case of being connected to the unit, a so-called open-time L level type photo interrupter which becomes L level when the optical paths from the light emitting elements of each pair to the light receiving element are both open can be configured. On the other hand, in each light receiving element, the collector is directly connected to the power supply connection lead portion, the emitter is connected to the ground side connection lead portion through the resistor, and the signal extraction connection lead portion is connected through the resistor. In the case of a phototransistor, it is possible to configure a so-called shut-off L level type photointerrupter which becomes L level when the light paths from the light emitting element of each pair to the light receiving element are both blocked.

Further, each light receiving element is composed of a photodiode, and after the output of each photodiode is amplified by an inverting or non-inverting amplifier, the collector is connected via a resistor to a power supply connection lead portion and a signal extraction connection lead portion. By connecting to the base of the transistor whose emitter is connected to the earth side connecting lead portion, a photo interrupter of open L level type or shielded L level type can be constructed.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to an embodiment shown in the drawings.

FIG. 1 shows an embodiment of the photo interrupter according to the present invention. The photo interrupter 10 has a case 11 having a leg portion 11a to be inserted into a mounting hole provided in a substrate or the like, and a case 11 thereof. It is composed of a light emitting portion 12 and a light receiving portion 13 which respectively project on the upper surface of the above, and a connector portion 14 provided at one end of the case 11.

The leg portion 11a of the case 11 has side portions projecting near the tip thereof, and engages with the back surface of the substrate or the like when inserted into a mounting hole of the substrate or the like, whereby the photo interrupter 10 is fixed to the substrate or the like. It has become so.

The light emitting section 12 and the light receiving section 13 respectively accommodate two pairs of light emitting elements 12a, 12b and light receiving elements 13a, 13b arranged in the lateral direction, and the light emitting windows 12c, 12d and the light receiving window 1 on the surfaces facing each other.
3c, 13d, each light emitting element 12a, 12b in the light receiving unit 12
From the light-receiving part 13 and the light-receiving part 13 and the light-receiving part 13 through the corresponding space 15 between the light-emitting part 12 and the light-receiving part 13. Element 13
It is incident on a and 13b respectively. Further, the connector portion 14 includes the light emitting elements 12a, 12b and the light receiving elements 13a, 13b.
It has three external connection lead terminals 14a, 14b, 14c for supplying power to or extracting signals.

FIG. 2 shows each light emitting element of the photo interrupter 10 shown in FIG.
12a, 12b and each light receiving element 13a, 13b, and external connection lead terminal
The connection state with 14a, 14b, 14c is shown. That is, in the illustrated case, the light emitting elements 12a and 12b are connected in series with each other, and the negative side of the light emitting element 12b is directly connected to the ground side connecting lead terminal 14a.
Further, the + side of the light emitting element 12a is connected to the power supply connection lead terminal 14b via the resistor 16. Light receiving element 13
a and 13b are phototransistors in this case, and their collectors are resistors (that is, DC limiting resistors) 17,1 respectively.
It is connected to the power supply connection lead terminal 14b via 8 and the signal extraction connection lead terminal 1 via resistors 19 and 20.
4c, and their emitters are directly connected to the earth side connection lead terminal 14a.

The photo interrupter 10 according to the present invention is configured as described above, and when the light paths from the light emitting elements 12a, 12b to the light receiving elements 13a, 13b are both blocked, the light receiving elements 13a, 13b are
Since no light is incident on b, and therefore the light receiving elements 13a and 13b are both in the off state, the voltage applied to the feeding connection lead terminal 14b is taken out through the resistors 17, 18, 19, 20. The signal lead-out connection lead terminal 14c is at the H level voltage equal to the voltage of the driving power source because the signal lead-out connection lead terminal 14c is added to the signal connection lead terminal 14c.

Here, when the optical paths from the light emitting elements 12a and 12b to the light receiving elements 13a and 13b are both opened, the light receiving elements 13a and 13b are connected to the light emitting element 12a.
Since the light from a and 12b is incident, both the light receiving elements 13a and 13b are turned on, which causes one end of the resistors 17 and 18 to be directly connected to the ground side connection terminal 14a, and thus the signal extraction The connection lead terminal 14c has an L level voltage equal to the above voltage.

By the way, when one of the optical paths from the light emitting elements 12a, 12b to the light receiving elements 13a, 13b, for example, only the optical path from the light emitting element 12a to the light receiving element 13a is opened, the light receiving element 1
Only 3a is turned on and one end of the resistor 17 is connected to the earth side connection lead terminal 14a, but the light receiving element 13b is in the off state, so the signal extraction connection lead terminal 14c
Is connected to the power supply connection lead terminal 14b via the resistors 18 and 20 and is connected to the ground side connection lead terminal 14a via the resistor 19, so that the first voltage between the H level and the L level is The voltage becomes an intermediate level voltage. Similarly, light emitting element
Even if only the optical path from 12b to the light receiving element 13b is opened,
Since it is connected to the power supply connection lead terminal 14b via the resistors 17 and 19 and connected to the ground side connection lead terminal 14a via the resistor 20, the voltage is at the second intermediate level.

The above-mentioned first and second intermediate level voltages are
Resistance value of 16,17,18,19,20 and connection lead terminal 14b for power supply
Is determined by the voltage V applied to the resistor. For example, the resistor 16 is 300Ω, the resistors 17 and 18 are 15 kΩ, and the resistors 19 and 20 are 30Ω.
When the voltage V is 5 kV at 0 kΩ and both optical paths are cut off, the voltage Vo of the signal lead-out connection lead terminal 14c is about 4.9.
5V (H level), if both optical paths are open, voltage
Vo is about 0.01V (L level), and when only one optical path is open, the voltage Vo is about 2.4V (first and second intermediate level), but resistors 17 and 18 and resistors 19 and 20 are It is also possible to give a voltage difference to the extent that the first and second intermediate levels can be discriminated by appropriately differentiating the resistance value of.
In this way, by inputting the change of the voltage Vo generated at the signal lead-out connection lead terminal 14c, that is, the H level, the L level, or the first and second intermediate levels to the appropriate control circuit, simply turning on and off A control operation of three stages or four stages, which is more complicated than the control operation of only a single switching, is possible.

FIG. 3 shows another circuit configuration having operating characteristics similar to those of FIG. In this case, as the light receiving elements 13a and 13b, a photodiode is used instead of the phototransistor, and the output of the photodiode is amplified by an amplifier and is then inserted through a buffer instead of the phototransistor of FIG. It is designed to be input to the base of. The photo interrupter 10 configured as described above operates in exactly the same manner as the photo interrupter in FIG. 2, and therefore its description is omitted.

FIG. 4 shows a modified example of the photo interrupter of FIG. 2, in which the collectors of the respective light receiving elements are directly connected to the power supply connection lead terminals 14b, and the emitters are connected to the earth side connection leads via resistors 21 and 22. Connected to terminals and resistance 1
It is connected to the signal output connection lead terminal 14c via 9,20.

According to this configuration, when both the optical paths are cut off, the phototransistor is in the off state, so that the signal lead-out connection lead terminal 14c becomes an L level voltage,
Also, when both optical paths are opened, the phototransistor is turned on, and therefore the signal lead-out connection lead terminal 14c
Becomes an H level voltage, and when only one optical path is opened, only one phototransistor is turned on. Therefore, the signal lead-out connection lead terminal 14c has an intermediate level voltage between the H level and the L level. For example, in the case of the same circuit constant as in FIG. 2, the H level is 4.
95V, L level is 0.01V, and intermediate level is 2.4V.

[Effect of device]

As described above, according to the present invention, when both optical paths are blocked, light does not enter the light receiving element, and therefore,
Both the light receiving elements output L level or H level signals, but when both optical paths are opened, the light receiving elements both output inverted H level or L level signals. When only one optical path is blocked, the two light receiving elements output H level and L level signals.

Therefore, a signal of H level, L level or an intermediate level is output to the signal extraction connection lead portion of the photo interrupter based on the open / closed state of each optical path.
As a result, the open / closed state of each optical path can be detected by the voltage of the signal lead-out connection lead portion. At that time, by appropriately selecting the resistance value of the resistor connected to the output of each light receiving element, it is possible to determine which optical path is blocked or open, and the two pairs of light emitting elements and Since the light-receiving element is housed in one case, it can be configured in a relatively small size, and since the number of connecting leads to two pairs of light-emitting elements and light-receiving elements is only three, wiring can be reduced. It will be simpler and assembly costs can be reduced.

Furthermore, in the photo interrupter according to the present invention,
When each light receiving element is a phototransistor whose collector is connected to the power supply connection lead portion and the signal extraction connection lead portion via a resistor, and the emitter is directly connected to the ground side connection lead portion, A so-called open-time L level photointerrupter, which is at the L level when the optical paths from the light emitting elements of each pair to the light receiving elements are both open, can be configured. On the other hand, each of the light receiving elements has a collector directly connected thereto. If the phototransistor is connected to the power supply connection lead part, the emitter is connected to the ground side connection lead part via a resistor, and is connected to the signal extraction connection lead part via a resistor, A so-called shielded L level photointerrupt that becomes L level when both the light paths from the light emitting element to the light receiving element are blocked. There would be constructed.

In addition, each light receiving element is a photodiode, and after the output of each photodiode is amplified by an amplifier, the collector is connected to the power supply connection lead portion and the signal extraction connection lead portion through resistors and the emitter Is input to the base of the transistor connected to the ground side connection lead portion, an L level type photo interrupter when open or an L level type when shielded can be constructed.

Thus, according to the present invention, due to the relatively small configuration,
Control is performed in multiple stages, and wiring is simple.
An extremely good photo interrupter is provided.

[Brief description of drawings]

FIG. 1 shows an embodiment of a photo interrupter according to the present invention, (A) is a plan view, (B) is a side view, and FIG.
It is a circuit diagram which shows the circuit structure of the photo interrupter of the figure. 3 and 4 are circuit diagrams showing other circuit configuration examples. FIG. 5 is a circuit diagram showing a circuit configuration of an example of a conventional photo interrupter. 10 ... Photo interrupter, 11 ... Case, 11a ... Leg part, 12 ... Light emitting part, 12a, 12b ... Light emitting element, 12c, 12d.
Light emitting window, 13 ... Light receiving part, 13a, 13b ... Light receiving element, 13c, 13d
...... Light receiving window, 14 ...... Connector part, 14a, 14b, 14c ...... External connection terminal, 15 ...... Space, 16,17,18,19,20 ...... Resistance.

Claims (1)

[Scope of utility model registration request] 1. A light-emitting element and a light-receiving element, which are arranged in a pair so as to face each other, and three external connection lead portions for power supply, signal extraction, and ground, each light-emitting element being connected for power supply. Driving light emission by being connected between the lead part and the earth side connecting lead part, and driving by connecting each light receiving element between the power supply connecting lead part and the earth side connecting lead part. In the photointerrupter, the output of each light receiving element is connected to the signal extraction connection lead portion via a resistor, respectively, and a current limiting resistor is connected in series with each light receiving element, and the light emitting element and the light emitting element are connected. According to the operating state of the light receiving element, the output signal of the H level, the L level and their intermediate level is obtained at the signal extracting connection lead portion. Photo-interrupter according to claim.