JPS6146785B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a direction detection device in which a light beam detector is capable of detecting the object itself and also identifying the moving direction of the object.

When using a conventional light beam detector not only to detect a moving object 5 such as a person, but also to identify and detect the moving direction of the object 5, it is necessary to use a light beam detector as shown in FIG. A plurality of pairs of light emitters 7' and light receivers 8' in a light emitting/receiving type light detector are provided, and these are disposed oppositely at front and back positions along the moving path of the detected object 5 so as to cross the moving path, By inputting the outputs of the light receivers 8' for each pair to the signal processing circuit 9, the order in which the detected object 5 is detected in each light receiver 8' is determined, thereby determining the moving direction of the detected object 5. I was doing it. However, in such a conventional example, a plurality of pairs of light emitters and receivers 7' and 8' are connected to the object to be detected 5.
Since the transmitters and receivers 7' and 8' need to be installed in the passage of There is a problem that the installation work required is expensive, and it is impossible to integrate the emitter and receiver, and if an integrated device is formed, it will be difficult to detect the moving direction of the object to be detected. There was a problem that made it impossible.

The present invention has been provided in view of the above-mentioned points, and has a structure in which at least a light projecting section and a light receiving section are integrated, thereby greatly simplifying the installation work and simplifying the structure of the light projecting and receiving section. To provide a direction detecting device which is inexpensive by being made more compact, has a light emitting and receiving part integrated, and is capable of identifying and detecting the movement of a detected object in any direction as necessary. The purpose is to

An embodiment of the present invention will be described in detail below with reference to the drawings.
FIG. 2 shows an example of a schematic configuration of the light projecting section 7 in an embodiment of the present invention.
A pair of light emitting elements 2 ₁ , 2 symmetrically with respect to the optical axis i of
₂ are arranged, and these light emitting elements 2
The light emitted from the light-emitting elements _{2-1 and 2-2} is respectively projected as shown in FIG _. The light is projected onto area D, respectively. Therefore, if the detected object 5 moves as indicated by the arrow in FIG. ₁ , the light from both the light emitting elements 2 ₁ and 2 ₂ , and the light from the light emitting element 2 ₂ are sequentially reflected or blocked by the detected object 5 .

Therefore, as shown in FIG. 3, if the light receiving section 8 is arranged so as to be able to receive and detect the reflected light reflected by the detected object 5 or the reflected light reflected by surrounding objects, blocked by the detected object 5. The movement of the object to be detected 5 can be identified and detected by the output of the light receiving element 4 in the light receiving section 8. That is, within the detection area, if the detection object 5 moves from a point H in area C to a point in area D as shown in the figure, the light receiving element 4 in the light receiving part 8 The reflected light from the detected object 5 from points E and F is received through the optical element 3 formed by a convex lens. However, since the reflected light at point E is the reflected light of the light projected by the light emitting element ₂₁ , and the reflected light at point E is the reflected light of the light projected by the light emitting element ₂₂ , the light receiving element 4 is As the detected object 5 moves from point E to point E, it first receives the reflected light from the light emitted by the light emitting element ₂₁ , and then receives the reflected light from the light emitted from the light emitting element ₂₂ . Therefore, if the light receiving element 4 can distinguish between the light reflected by the light emitting element ₂₁ and the light reflected by the light emitting element ₂₂ , the direction of movement of the object to be detected 5 can be detected.

By the way, in the above explanation, as shown in FIG.
A pair of light emitting elements 2 ₁ , 2 ₂ with a positional relationship of °
In this example, the light emitting element 2
The moving direction of the detected object 5 in the detected area parallel to the arrangement direction of the light emitting elements 2 ₁ , ₂ 2 can be detected, but on the other hand, the moving direction of the detected object 5 in the direction perpendicular to the arrangement direction of the light emitting elements 2 ₁ , 2 ₂ can be detected. The direction of movement cannot be detected. Therefore, as shown in FIG. 5, four light emitting elements 2 ₁₁ ,
2 ₁₂ , 2 ₂₁ , 2 ₂₂ are arranged, and the light emitting elements 2 ₁₁ ... 2 ₂₂ , each located at a symmetrical position with respect to the optical axis A, are paired and the reflected light due to the light emission is made to differ in a distinguishable manner on the light receiving element. , it is possible to eliminate the blind spots in movement direction detection as described above. If a larger number of light emitting elements 2 ₁₁ are arranged, the movement direction in all directions can be detected even more reliably, and in this case as well, each light emitting element 2 ₁₁ is located at a symmetrical position with respect to the optical axis A.
... are made into a pair, and the light emitting forms of the light emitting elements 2 ₁₁ ... of each pair are made to differ so as to be distinguishable from each other on the light receiving element 4 side, and if necessary, the light emitting forms of the light emitting elements 2 ₁₁ ... of other pairs are made different. Both are made to be distinguishable on the light receiving element 4 side.

In the embodiment shown in FIG. 3, the light receiving section 8 is arranged adjacent to the light emitting section ₇ , but as shown in the embodiment shown in _FIG. The light-receiving element 4 is arranged above, and the optical element 1 on the light-emitting part 7 side and the optical element 3 on the light-receiving part 8 side are shared, so that the light-emitting and receiving parts 7 and 8 integrated in this way are integrated into one.
An integrated direction detection device may be constructed by housing the light emitting elements 2 11 in one container body 6, and the same is true when the number of light emitting elements 2 ₁₁ . . . is plural pairs.

Next, a light emitting form in the light emitting elements 2 ₁₁ . . . for making the light reflected by the light emitted by the light emitting elements 2 _{11 .} . . distinguishable on the light receiving element 4 side will be described. As a light emitting form of the light emitting elements 2 ₁ and 2 ₂ , for example, the paired light emitting elements 2 ₁ and 2 ₂ may be made to emit light alternately, or the light emitting elements 2 ₁ and 2 ₂ may be modulated with a predetermined frequency signal. The light modulation frequencies for emitting light may be made to be different from each other, or the light emitting elements 2 ₁ and 2 ₂ may be made to emit light by combining both of the above.

Figure 7 shows an oscillation circuit using a pair of light emitting elements 2 ₁ and 2 ₂ .
An example is shown in which the output of OSC ₂ is used to alternately emit light. In this embodiment of FIG. 7, the light emitting elements 2 ₁ and 2 ₂ are given optical modulation by the output of the modulating oscillator OSC ₁ , and the light emitted by both the light emitting elements 2 ₁ and 2 ₂ can be distinguished from other natural light. is made possible. That is, the oscillation circuit OSC ₂ controls the light emitting element drive circuit 10 by its output, amplifies the output of the modulation oscillator CSC ₁ , and then alternately drives the light emitting element 2.
Therefore _, the light emitting elements 2 ₁ and _{2 2 are} optically modulated by the output of the modulation oscillator OSC ₁ and emit light alternately, as shown in FIG. 8 a and b, respectively. It turns out. On the other hand, on the light receiving unit 8 side, the light receiving element 4 detects the reflected light of the light projected from the light projecting unit 7 by the detected object 5 (or the shielding of surrounding reflected light by the detected object 5, the same applies hereinafter), This signal is amplified by the amplifier 11 and then input to the signal processing circuit 9. The signal processing circuit 9 is the amplifier 11
The output of the oscillation circuit OSC ₂ is input as well as the output of the oscillation circuit OSC 2, and the output of the oscillation circuit OSC ₂ causes the light reception signal at that timing to be transmitted to the light emitting elements 2 ₁ ,
₂ The presence of the moving detected object 5 is determined by identifying which of the 2 is the light emission and detecting whether or not a change has occurred in the light reception signal, and thereby the light emitting elements 2 ₁ , 2 The direction in which the detected object 5 moves is determined by detecting the order in which the light projected from the detected object ₂ is received and reflected by the detected object 5.

FIG. 9 shows a more detailed block circuit diagram of the embodiment of FIG. That is, in this embodiment circuit of FIG. 9, the circuit configuration of the signal processing circuit 9 is shown in more detail, and the light projecting section 7 side has the same configuration as the circuit of FIG. 7. However, in the embodiment circuit of FIG. 9, in the signal processing circuit 9, the output of the amplifier 11 is inputted to the filter 12, and the frequency component of the modulated signal given to the light emitting elements 2 ₁ and 2 ₂ is Only the light emitting elements 2 ₁ , 2 are allowed to pass through.
Only the reflected light of the light projected by ₂ is extracted. Next, the selection processing circuit 13 transmits the output of the filter 12 to the first signal processing section 14 and the second signal processing section by the output of the oscillation circuit OSC ₂ .
The signal processing unit 15 is configured to distribute the reflected light signal from the light emitting element ₂₁ to the first signal processing unit 14, and the light signal reflected from the light emitting element 21 to the first signal processing unit 14.
The reflected light signals from ₂ are input to the second signal processing section 15, respectively, and these first and second signal processing sections 14, 1
5, the reception signals of the reflected light emitted by the light emitting elements 2 ₁ and 2 ₂ are individually processed, and the presence or absence of the detected object 5 is determined. In this way, the moving direction determination circuit 16 has the first and second signal processing sections 1
By determining whether or not a detection signal of the detected object 5 is generated first in either of 4 and 15, the detection signal of the detected object 5 is detected.
, and when it is determined that the detected object 5 has moved in a predetermined movement direction, the output circuit 1
Activate 7.

FIG. 10 shows first and second signal processing circuits 14 and 15.
7 is a more detailed block circuit diagram of the embodiment shown in FIG. 7, and in the embodiment shown in _FIG . A preamplifier 18 is provided, and the output of the preamplifier 18 is input to the selection processing circuit 13 of the signal processing circuit 9 and distributed to the first and second signal processing sections 14 and 15. The first and second signal processing sections 14 and 15 each include an amplification section 19 that amplifies the output of the selection processing circuit 13, a detection section 20 that detects the output of the amplification section 19 and converts it into a voltage level signal, and a detection section. 20; a memory unit 22 that stores the output of the time lag unit 21; and a memory unit 22 that stores the received light input state a predetermined time ago stored in the memory unit 22 and the current received light input output from the detection unit 20. The output of the change detection unit 23 is transferred to the operation holding unit 24 during a period in which an input is generated to the signal processing units 14 and 15 of the change detection unit 23 that detects a change in the light reception input state by comparing the state with the state. The object to be detected 5 is detected by detecting a change in the light reception signal corresponding to each light emitting element 2 ₁ , 2 ₂ sorted by the selection processing circuit 13 . The outputs of the first and second signal processing units 14 and 15 are input to the moving direction determining circuit 16.

FIG. 11 shows a specific circuit example of the light projecting section ₇ of _the embodiment _{shown in FIG .} It consists of NAND gates NAND ₁ , NAND ₂ and transistor Tr ₃ ,
Tr ₄ constitutes a light emitting element driving circuit 10, and the modulated light modulated by the output signal of the modulation oscillator OSC ₁ is transmitted to the light emitting element 2 made of a light emitting diode.
₁ , 2, _{and 2} are made to emit light alternately. Further, FIG. 12 shows an example of the circuit configuration of the moving direction determination circuit 16 including the motion holding sections 24, 24.
Detection output 1 and detection output 2 obtained as outputs of both signal processing units 14 and 15 are held for a certain period of time by first and second operation holding units 24 and 24, respectively, and are further held by first and second time lag units 26 and 27. The holding state of the first detection output in the operation holding section 24 is maintained from when one detection output is generated until the other detection output is generated when the same detected object 5 passes after obtaining a predetermined delay time. This is determined by a motion direction determination section centered on the first and second flip-flops FF ₁ and FF ₂ , and which one of the first and second motion holding sections 24 and 24 is determined first. It is determined whether the operation holding state has been reached, and a moving direction determination output is generated at the Q output of the first or second flip-flop FF ₁ or FF ₂ at the time when the operation holding state of the operated side is entered. FIG. 13 shows a time chart of the operation of the flip-flops FF ₁ and FF ₂ , in which a indicates the clock pulse CP and b indicates the clock pulse CP.
d and e indicate the reset pulse R, the data pulse D, and the Q and output signals, respectively.

FIG. 14 shows that a pair of light emitting elements 2 ₁ and 2 ₂ are modulated with different modulation frequency signals, and the light emitting elements 2 ₁ and 2 ₂ are modulated by changing the modulation frequency of light modulation.
This makes it possible to identify the reflected light caused by the However, in the embodiment of FIG. 14, oscillation circuits OSC ₁₁ and OSC ₁₂ with oscillation frequencies of ₁ and ₂ are used, respectively.
The light-emitting elements 2 ₁ and 2 ₂ are caused to emit light by the outputs of the light-emitting elements 2 1 and 2 2 . On the light-receiving section 8 side, the outputs of the light-receiving elements are input to filter circuits 28 and 29 whose passing frequencies are ₁ and _2, respectively, so that the light-emitting elements 2 1 and 2 2 emit light. ₁ , 2 ₂
After detecting the outputs of these filter circuits 28 and 29 in the detection sections 20 and 20, the change detection section 2
3 detects the object 5 to be detected, and connects the first and second flip-flops FF ₃ , FF ₄ and the AND gates AND ₁ ,
A movement direction determination circuit 16 consisting of AND ₂ determines which of the two change detection units 23, 23 generates a detection output first, and operates an output circuit 17 which also serves as a display. .

FIG. 15 shows a modulation oscillator that outputs different frequency signals ₁ and ₂ from light emitting elements 2 ₁ and _{2 2} , respectively.
The OSC ₁₁ and OSC ₁₂ emit modulated light, and the two light emitting elements 2 ₁ and 2 ₂ alternately emit light using the output of the oscillation circuit OSC _2. The embodiment shown in FIG. 7 and the embodiment shown in FIG. It corresponds to a circuit that combines the following. However, this embodiment circuit performs a circuit operation that is a combination of the operation of the embodiment circuit in FIG. 7 and the operation of the embodiment circuit in FIG.
₁ , 2, _{and 2} , and therefore the light reflected by the detected object 5 due to the respective light emissions, can be identified and detected on the light receiving section 8 side.

If you want to change the direction _of movement to be detected after installation, for _{example ,} as shown in _FIG . This can be easily done by providing a switch and switching the changeover switch SW.

Further, in the above embodiment, an example was shown in which convex lenses were used as the optical elements 1 and 3, but it goes without saying that concave mirrors may be used.

Since the present invention is configured as described above, it is possible to perform reliable detection of the moving direction of the detected object with a simple structure.
In particular, it is possible to detect the direction of movement by simply providing one light projector, and by configuring it as a reflected light type light beam detector, there is no need to adjust the optical axis, and it has extremely good workability. It also has the effect of being easily configured as a body shape.

[Brief explanation of the drawing]

Figure 1 is an example circuit diagram of a conventional direction detection device, Figure 2
The figure is an explanatory diagram of the principle of the present invention, Figure 3 is a schematic diagram of the arrangement of the light emitting and receiving parts same as above, Figure 4 is a diagram of the arrangement of light receiving elements same as above, and Figure 5 is an arrangement of two pairs of light receiving elements same as above. FIG. 6 is a schematic sectional view of another embodiment in which the light emitting and receiving parts are integrated, and FIG. 7 is a diagram of the embodiment in which a pair of light emitting elements are used to alternately emit light. A schematic block diagram, FIG. 8 is a time chart showing the light emitting state of both light emitting elements of the above embodiment, FIG. 9 is a block diagram of a specific circuit example of the above embodiment, and FIG. 10 is another specific circuit of the same embodiment. FIG. 11 is a specific circuit example diagram of the light projecting section of the same embodiment, FIG. 12 is a specific circuit example diagram of the moving direction determining circuit of the same embodiment, and FIG. 13 is a specific circuit diagram of the moving direction determining circuit of the same embodiment. A time chart for explaining the operation of a flip-flop; Fig. 14 is a block diagram of an embodiment in which both light emitting elements of the present invention are made to emit light at different modulation frequencies; Fig. 15 is a time chart for explaining the operation of both light emitting elements of the present invention at different modulation frequencies. A block diagram of an embodiment in which light is emitted and the light is emitted alternately. FIG. 16 is a block diagram of a light projecting unit in which the judgment movement direction of the same as above is switched. 1 is an optical element, and 2 ₁ and 2 ₂ are light emitting units. 3 is an optical element, 4 is a light receiving element, 5 is an object to be detected, 6 is a container body, 7 is a light projecting section, and 8 is a light receiving section.

Claims (1)

[Claims] 1. Near the focal point of a condensing optical element such as a convex lens or a concave mirror, one or more pairs of light emitting elements are arranged around the optical axis in a substantially axisymmetric manner with respect to the optical axis of this optical element. A light projecting section arranged at approximately equal intervals in the direction and emitting light from both light emitting elements in each pair in a mutually distinguishable manner, and a focal point of a condensing optical element such as a convex lens or a concave mirror. A light-receiving element is arranged to be able to receive the reflected light emitted by each of the light-emitting elements, and an identification means for inputting the output of the light-receiving element and identifying the reflected light of each light-emitting element based on the difference in the light emission mode, and each light-emitting element. A direction detection device comprising a light receiving section, which is equipped with a change detection means for detecting a change in the reflected light of each light emitting element, and determines the moving direction of a detected object by detecting the order of changes in the received light reflected by each light emitting element. . 2. The light emitting part and the light receiving part are housed in one container,
Claim 1 characterized in that the optical element on the light projecting section side and the optical element on the light receiving section side are shared.
Direction sensing device as described in section. 3. The direction detection device according to claim 1, wherein the light emitting elements of each pair of the light projecting section are made to emit light alternately. 4. The direction detection device according to claim 1, wherein at least one or more pairs of light emitting elements of the light projecting section are modulated at mutually different modulation frequencies to emit light. 5. The direction detection device according to claim 4, wherein at least one or more pairs of light emitting elements that emit light by being modulated with different modulation frequencies are made to alternately emit light.