JPH0232582B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in direction sensing type optical relays.

2. Description of the Related Art A direction sensing optical relay shown in FIG. 1 has been conventionally known. That is, A is a light projecting section, which includes a light emitting element A ₁ and an optical system (for example, a semi-parabolic reflecting mirror A ₂ ) for projecting the light emitted from the light emitting element A ₁ to a detection area as a parallel beam. and an oscillation circuit A ₄ and a drive circuit A ₃ for projecting modulated light from the light emitting element A ₁ . B ₁ and B ₂ are two light receiving parts,
An optical system that focuses light on the light receiving elements B ₁₂ and B ₂₂ , such as convex lenses B ₁₁ and B ₂₁ , and a tuned amplification circuit that is synchronized with the light emission period that amplifies the output of the light receiving elements B ₁₂ and B ₂₂ .
B ₁₃ , B ₂₃ and low-pass filters B ₁₄ , B ₂₄ ,
Low-pass amplifier B ₁₅ , B ₂₅ and level detection circuit
Consists of B ₁₇ and B ₂₇ . C is a signal processing circuit which prevents the output of the differential phase detection circuit _C1 from being sent to the next stage when the outputs of the differential phase detection circuit _C1 , the in-phase detection circuit _C2 , and the in-phase detection circuit exist. It consists of gate C ₃ and monostable multi C ₄ . D is a display means, for example, a speech synthesis circuit _D1 and an amplification circuit.
It consists of D ₂ and speaker D ₃ . E is a changeover switch used to match the moving direction of the object with the display means. The light-receiving ranges Y ₁ and Y ₂ received by the light-receiving parts B ₁ and B ₂ are dimensioned so that there is a range where light is simultaneously received by the object to be detected.
L ₀ is configured to be smaller than the width of the detection object. Therefore, when an object enters the detection area from the _P1 direction, the waveforms of each part become signals as shown in the left column of FIG. That is, when B ₂ starts receiving light while B ₁ is receiving light, output C ₄₂ is output. Also, when an object enters the detection area from the _P2 direction, it will be as shown in the right column of Figure 2, and if both light receiving parts receive light at the same time (see the center column of Figure 2), it will be output as an erroneous signal. Not issued.

However, α ₁ and α ₂ in Figure 2 A and B are the values obtained by receiving the reflected light reflected by a moving object, and β ₁ and β ₂
is the amount of light that is constantly reflected and received by a stationary object such as a wall, but as shown in Fig. In cases where there is almost no difference in the amount of light received by the light receiving sections that receive light reflected by an object when a person passes by, and the change ΔF is very small, the change in the amount of light received by both light receiving sections is When there is a difference in the output of the detection circuit, for example, the amplification degree is different, the conversion rate of the light receiving elements B ₁₂ and B ₂₂ is different, or the difference between the light receiving elements B ₁₂ and B ₂₂ and the lenses B ₁₁ and B ₂₁ is different. If one of the optical axes is misaligned or otherwise different, there is a risk that the detection area will be displayed as if it were entered from the opposite direction to the direction of movement, as shown in FIG. In other words, since the object is moving from direction P1 in Figure ₁ , the outputs of amplifiers B ₁₃ and B ₂₃ change more quickly than the output of B ₁₃ , as shown by [T] in Figure 4. Regardless, since the degree of amplification is different, the change in output will be ΔF ₁ < ΔF ₂ ,
The output timing of the level detection circuits B ₁₇ and B ₂₇ is earlier in the second light receiving section B ₂ by ΔT. Therefore, the output signal is as if the object was moving from the _P2 direction. This causes what is called a malfunction.

The present invention aims to improve the above-mentioned drawbacks, and is a direction-sensing optical relay in which the outputs of the change detection circuits in response to changes in the amount of light received by both light receiving sections B ₁ and B ₂ are approximately equal. It is.

The present invention will be described in detail below using examples.

FIG. 5 is a front view of the direction sensing optical relay according to the present invention, in which 1 is the main body, 2 is the joint, and 3 is the front view of the direction sensing optical relay according to the present invention.
is the mounting part. There is a transparent plate 4 on the front of the main body 1. Modulated light from the light projecting section A is projected onto the detection area through the transparent plate 4, and light reflected by an object also passes through the transparent plate 4 to the light receiving section B. Light is received. FIG. 6 shows a perspective view of a printed circuit board block equipped with a light emitting section A, both light receiving sections B ₁ and B ₂ , a signal processing circuit C, etc. The light emitting element A ₁ is soldered to the front central part of the printed board 5. This light emitting element
The modulated light from A ₁ is reflected by semi-parabolic reflector A ₂ ,
The light is projected as parallel rays. On both sides of this light projecting part A, light receiving parts B ₁ and B ₂ are arranged. _B11 is a lens that focuses light reflected by an object onto the light receiving element _B12 . Similarly, B ₂₁ is a lens and B ₂₂ is a light receiving element. And 6 indicates a non-transparent material coated on the lens _B11 . By applying this non-transparent material, the amount of light received by the light receiving portion _B1 is reduced. The non-transparent material is applied to an area so that the output of the change detection circuit with respect to the amount of received light becomes the same. In other words, the amount of received light is increased sequentially, and adjustments are made so that the points at which the outputs of the level detection circuits B ₁₇ and B ₂₇ are inverted are the same.

Therefore, both light receiving sections are
The reversal timing of the outputs of the level detection circuits B ₁₇ and B ₂₇ of B ₁ and B ₂ is not as shown in Fig. 4, but in a certain order determined by the moving direction of the object as shown in Fig. 2 F and G. This makes it possible to display images appropriate for the direction in which the object is moving.

In addition, as shown in Figure 7, a variable resistor RV or
RV ₃ is provided, and by adjusting any one of these, the amplification degree and detection level can be adjusted, so that the output of the level detection circuit is inverted in the same way for the same change in the amount of received light. It is possible to

Also, for example, it is desirable that the centers of the light-receiving lenses B ₁₁ and B ₂₁ and the centers of the light-receiving elements B ₁₂ and B ₂₂ coincide, but by shifting the optical axis of the lens of one of the light-receiving parts and the light-receiving element, It is also possible to achieve the same objective.

As described above, according to the present invention, a light projecting section that projects modulated light, and two light receiving sections that receive reflected light that is the modulated light projected from the light projecting section reflected by an object, An optical relay comprising a signal processing circuit including a moving direction discrimination circuit that discriminates the order in which light is received by the two light receiving sections and outputs different signals depending on the moving direction of the object, and a display means driven by the output of the signal processing circuit. In the above, the light receiving section is composed of a light receiving element, an optical system for condensing reflected light onto the light receiving element, and a change detection circuit connected to the rear stage of the light receiving element, including an amplification circuit, a detection circuit, a level detection circuit, etc. detect the minimum interval between the light receiving ranges of the two light receiving parts; By using a direction-sensing optical relay in which the outputs of the change detection circuits corresponding to changes in the amount of light received by the two light receiving sections are approximately equal so as to be smaller than the width of the object, Since the output of the level detection circuit is inverted, the direction of movement of the object can be accurately detected. Further, it is extremely simple to equalize the outputs of the level detection circuits of both light receiving sections B ₁ and B ₂ , and the assembly of the product is also facilitated.

[Brief explanation of drawings]

1 to 4 are diagrams showing a conventional example of the present invention, in which FIG. 1 is a block diagram and FIG. 2 is a waveform diagram of various parts of the block diagram shown in FIG. 1. Third
Both Fig. 4 and Fig. 4 are output waveform diagrams. 5 to 7 show one embodiment of the present invention, in which FIG. 5 is a front view, FIG. 6 is a perspective view of a printed circuit board block, and FIG. 7 is a block diagram of a light receiving section. 1: Main body, 2: Joint, 3: Mounting base, Figure 4 shows a transparent plate. 6 is a non-transparent material coated on the lens B ₁₁ , A: Light projecting section, B ₁ , B ₂ : Light receiving section, C:
Signal processing circuit, D: indicates display means.

Claims (1)

[Claims] 1. A light projecting section that projects modulated light, two light receiving sections that receive the modulated light that is the modulated light projected from the projecting section and reflected by an object, and these two light receiving sections. An optical relay is equipped with a signal processing circuit including a moving direction discrimination circuit that discriminates the order of light reception by the light receiving section of the object and outputs different signals depending on the moving direction of the object, and a display means driven by the output of this signal processing circuit. The part is composed of a light receiving element, an optical system for condensing reflected light onto the light receiving element, and a change detection circuit connected after the light receiving element, including an amplifier circuit, a detection circuit, a level detection circuit, etc. There is a light receiving range of the two light receiving parts that simultaneously receives the modulated light reflected by the object to be detected, and
Direction detection characterized in that the outputs of the change detection circuits corresponding to changes in the amount of light received by the two light receiving sections are made approximately equal so that the minimum interval between the light receiving ranges of the two light receiving sections is smaller than the width of the detected object. Optical relay. 2. The optical system of the light receiving sections is coated with a non-transmissive material to substantially adjust the light collection rate so that the outputs of the change detection circuits corresponding to changes in the amount of light received by the two light receiving sections are approximately equal. A direction sensing optical relay according to claim 1. 3 By adjusting the amplification and detection levels of the amplification circuit and level detection circuit of the change detection circuit of the light receiving sections, the output of the change detection circuit in response to changes in the amount of light received by the two light receiving sections can be made almost equal. A direction-sensing optical relay according to claim 1.