JPH0530231Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention is a light beam that connects a light transmitter and a light receiver placed in a restricted area with a warning light beam, and issues an alarm when this warning light beam is interrupted. Regarding the type warning device.

[Conventional technology]

Conventionally, there are two types of security devices of this type. The first type is called a facing type in which a warning light transmitter and a light receiver are placed opposite each other across a warning area. The second type is called a reflective type, in which a light transmitter and a reflector for warning light beams are placed opposite to each other across a warning area, and a light receiver is placed to face the reflector. As the warning light, invisible line-of-sight, usually pulsed modulated infrared light, is used.

FIG. 7 shows a modification of the opposing type, which will be explained below. In addition, the meaning of "vigilance" in this specification is not only in the sense of crime prevention, such as preparing for a thief or the like to forcibly enter a specific area, but also in the sense of preventing danger, such as preventing children, etc. from entering a dangerous area. shall also be included.

Referring to FIG. 7, a warning light transmitting/receiving device 12 is installed at each of the four corners of a rectangular dangerous area 11. Each of these light transmitting/receiving devices 12 sends out a warning light beam 13 almost horizontally along the edge of the dangerous area 11, and the opposing light transmitting/receiving device 12
It receives the warning light beam 13 sent out from. The warning light beam 13 is sent out to a position lower than the height of a normal person. Now, when the warning light beam 13 is blocked, the light transmitting/receiving device 12 that received it issues a warning to the dangerous area 11 and its surroundings. Therefore,
This can contribute to preventing outsiders from entering the dangerous area 11. When used as a security device, it notifies a monitoring center etc. of the presence of an intruder.

FIG. 8 shows an example of the internal configuration of the light transmitting/receiving device 12. This light transmitting/receiving device 12 includes one body 14 made of plastic with high infrared transmittance. The body 14 has a rectangular or cylindrical appearance, for example. The interior of the fuselage 14 is partitioned into four spaces in the vertical direction. These spaces include, in order from the top, a warning device 15, a light receiver 16, and a light transmitter 1.
7 and an alarm signal generating section 18 are provided.

The light transmitter 17 emits pulsed modulated infrared light, which is the warning light beam 13. This pulsed modulated infrared rays are transmitted and received by passing through the side wall of the body 14, and further transmitted through the side wall of the body 14 of another light transmitting/receiving device 12 and entering the light receiver 16.

The light receiver 16 receives pulsed infrared light transmitted through the side wall of the fuselage 14, that is, a warning light beam from another light transmitting/receiving device 12, and issues a cutoff signal when the received light disappears or decreases.

The alarm signal generator 18 is a message reproducing device such as a tape recorder or a voice synthesis circuit, and is activated by the above-mentioned cutoff signal from the light receiver 16. Preferably, the message is, for example, "Kokoha, Kikendesunode, Tachiiranaidekudasai."

The warning device 15 is, for example, a speaker, and amplifies and emits the above-mentioned message.

Such a warning device is, for example, disclosed in Japanese Unexamined Patent Application Publication No. 1983-
This is shown in Publication No. 229196.

[Problem that the invention attempts to solve]

By the way, the above-mentioned light transmitting and receiving device is usually installed outdoors except in special cases. Therefore, on the plane through which the warning beam passes through the fuselage 14,
Snow and frost may accumulate in the winter, causing a decrease in the amount of light transmitted from the transmitter and the amount of light received by the receiver. On the other hand, the conventional light transmitting/receiving device described above is
Send light with an excessive amount of light that allows operation even if the amount of light incident on the receiver decreases to about 1/10 to 1/100 of the normal value, that is, a light amount that is several tens to 100 times the minimum required light amount. That's what I do. however,
When snow or frost accumulates, the amount of light incident on the receiver may decrease by more than 1/100, and in this case, the receiver assumes that there is an intrusion and generates a cutoff signal. Therefore, there is also a light transmitting/receiving device in which heaters are provided at a plurality of locations on the body of the light transmitting/receiving device, and power supply to the heaters is automatically controlled according to the outside temperature. However, in this case, when the outside temperature drops, all heaters are always energized regardless of the possibility of snow, frost, etc. occurring. Therefore, there is a drawback that power consumption increases and the temperature inside the machine increases excessively.

In view of the above points, the present invention detects the presence or absence of snow or frost itself in a light transmitting and receiving device that has snow removal and defrosting functions using a heater, and energizes only the heaters at the detected locations. It is an object of the present invention to provide a light beam type warning device that can prevent false detection due to adhesion of frost, etc., and can reduce power consumption.

[Means for solving problems]

The present invention is a light-based warning device that detects that a warning light beam is interrupted and issues an alarm, and includes a detector that detects snow, frost, etc. adhering to a surface through which the warning light beam is in contact with the outside air; The apparatus is characterized by comprising a heater for heating the surface through which the warning light beam passes, and a circuit for controlling energization of the heater in accordance with a signal from the detector.

[Effect]

With this configuration, when it is detected that snow, frost, etc. has adhered to the transmitting surface of the warning light, electricity is passed through the heater provided on that transmitting surface to remove the snow or frost and prevent a decrease in the amount of light transmitted and received.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 2 shows an example of a detector that detects snow, frost, etc. adhering to the surface through which the warning light passes. A light transmitting element 22 and a light receiving element 23, which generate infrared light beams different from the warning light beam, are located inside the fuselage 21 (corresponding to the fuselage 14 in FIG. 8) and adjacent to the light transmitter or the light receiver. It is located in This is because under normal conditions, the infrared rays from the light transmitting element 22 pass through the body 21, and when the transmitting surface of the body 21 is covered with deposits 24 such as snow or frost, the infrared rays from the light transmitting element 22 pass through the body 21. is reflected at the boundary between the transmitting surface of the body 21 and the deposit 24 and is incident on the light receiving element 23. The light transmitting element 22 and the light receiving element 23 may be, for example, a combination of a light emitting diode LED and a phototransistor, a combination of a light bulb and a CDS, or the like. It goes without saying that the light receiving element 23 is installed so as not to receive the warning light beam.

Figure 1 shows the light transmitting element 22 and light receiving element 23 in Figure 2.
Shows the connection configuration for. A collector emitter of a driving transistor 25 is connected in series to the light transmitting element 22. At the base of the driving transistor 25 is an oscillation circuit 2 that outputs pulses of several hundred Hz to several kHz.
6 is connected. On the other hand, the level detection circuit 29, which is connected to the emitter side of the light receiving element 23 via a capacitor 28, goes high only when the voltage generated across the resistor 31 exceeds a predetermined value. Outputs level signal. A holding circuit 30 having a time constant longer than the oscillation period of the oscillation circuit 26 is further connected to the level detection circuit 29 . The holding circuit 30 holds the signal output of the level detection circuit 29 for a certain period of time. The output of the holding circuit 30 is connected to the base of a relay driving transistor 32. A relay R _L is connected to the collector of the relay driving transistor 32 . relay
A series circuit of the normally open contact rl of R _{L and} the heater 33 is connected to a power source. As will be described later, the heater 33 is installed directly or adjacent to the warning light transmitting surface of the light transmitter and the light receiver in the light transmitting and receiving device.

Referring to FIG. 2, while the warning light transmitting and receiving device is operating, the light transmitting element 22 continues to transmit pulsed infrared light toward the transmission surface of the aircraft body 21. However, if there is no deposit on the transmitting surface of the body 21, most of the infrared light from the light transmitting element 22 will pass through the body 21 and will not enter the light receiving element 23.
Therefore, almost no voltage is generated in the resistor 31 connected to the light receiving element 23, and there is no signal output from the level detection circuit 29. As a result, there is no signal output from the holding circuit 30, the relay driving transistor 32 remains off, and the relay R _L is also off. Therefore, the heater 33 is not energized either.

Next, when snow or frost adheres to the transmitting surface of the body 21, the infrared rays from the light transmitting element 22 are reflected toward the light receiving element 23 due to the presence of the adhered material. As a result, a pulsed voltage is generated in the resistor 31. The level detection circuit 29 outputs a high level signal when the voltage generated in the resistor 31 exceeds a predetermined value, and the holding circuit 30 holds the output of the level detection circuit 29 for a certain period of time. Holding circuit 30
Since the holding time is longer than the oscillation period of the oscillation circuit 26, the holding circuit 30 continues to output the signal as long as there is a deposit on the transparent surface of the aircraft body 21.
As a result, the relay R _L operates, the contact R _L is closed, and the heater 33 is energized. In this way, snow and frost adhering to the transmission surface of the body 21 are heated and removed by the heater 33. When the snow and frost adhering to the transmitting surface disappear, almost no light is received by the light receiving element 23, and the heater 33 is turned off.

In this way, this device detects whether there is snow or frost on the surface through which the warning light passes through each of the warning light transmitters and receivers, and when it detects the presence of snow or frost, the heater corresponding to the transmitting surface is activated. By turning on electricity to melt and remove accumulated snow and frost, it prevents a drop in light transmitting output and light receiving input. In this way, providing a detector, a heater, and its control circuit for each light transmitter and light receiver and controlling the heaters individually is effective in the following points. In other words, in the light transmitting and receiving device as shown in FIG. 8, when it is snowing or extremely cold and the wind is blowing toward the light transmitter 17 as shown in the figure, the snow or frost may be removed from the transmitting surface on the light transmitter 17 side. Easy to adhere to. Therefore, in this case, the heater is energized by the light transmitter 17.
It is possible to save the power required to power the heater on the light receiver 16 side as in the conventional case. Further, since there is no excessive heater heating, the temperature inside the fuselage 14 does not rise excessively.

Note that the capacitor 28 connects sunlight to the light receiving element 23.
The purpose of this is to remove a certain DC component that occurs when the current is incident on the In addition, the light receiving element 2
By providing an optical filter that transmits only infrared rays on the light receiving surface of No. 3, the influence of sunlight can be further reduced.

FIGS. 3 and 4 are diagrams showing the relationship between the warning light transmitter 17 (or light receiver), the heater 33, and the snow or frost deposit detector in the light transmitting/receiving device. The heater 33 is a rectangular sheath heater that is connected to the light transmitting surface 17-1 of the light transmitter 17 and the fuselage 2.
1 and 1. Of course,
The heating element is not limited to a sheath heater, but may be a resistance heating element made by depositing metal on a transparent heat-resistant resin, for example. In either case, the heater is a light transmitter,
When adjusting the optical axis of the receiver, they are made to move together.

Fig. 5 shows another example of a heater control circuit. In this example, the contact _RL of relay _RL , a temperature switch 34 such as a thermostat that detects the outside air temperature, a temperature fuse 35, and a heater 33 are connected in series to the power source. The temperature switch 34 turns on when the outside air temperature drops to a predetermined value. On the other hand, the temperature fuse 35 is provided near the heater 33 and melts when the heater 33 becomes abnormally hot.

With this configuration, the fuselage 21 is compatible with factors other than snow and frost, such as the light transmitting element 22 (FIG. 3).
A malfunction such as relay R _L operating and energizing heater 33 can be prevented by small pieces such as paper scraps sticking to the transparent surface of the heater 33 . That is, if the outside air temperature is higher than the set temperature of the temperature switch 34, there is almost no risk of snow or frost adhering to the transmitting surface of the aircraft body 21, so under this condition the amount of light received by the light receiving element 23 will increase. Even if there is a problem, the heater 33 is prevented from being energized.

On the other hand, if the outside air temperature is below the set temperature of the temperature switch 34 and the amount of light received by the light receiving element 23 increases due to factors other than snow or frost, such as the above-mentioned paper scraps, and the heater 33 is energized, the heater 33 Abnormal heating can be prevented by the temperature fuse 35.

Although one embodiment of the present invention has been described above, various other modifications are possible. For example, as shown in FIG.
A light receiving element 23' may be provided inside the light receiving element 2'. That is, an infrared light beam different from the warning light beam is transmitted from the light transmitting element 22' to the light receiving element 23' through the transmission surface of the aircraft body 21. In this case, if snow, frost, etc. do not adhere to the transmission surface of the aircraft body 21, a pulse-like output is obtained from the light receiving element 23', and when snow, frost, etc. adhere to the transmitting surface, a pulse-like output is obtained from the light transmitting element 22'. Since infrared light is scattered by snow (or frost), the light receiving element 23'
has almost no optical input and no output. Therefore, the level detection circuit 29 in FIG. 1 may be configured so that it does not output a signal while there is a pulsed voltage input, and outputs a high level signal when the voltage input disappears. In addition, in FIGS. 2 and 6, the light transmitting elements 22 and 22' each emit continuous pulsed infrared light, but this is done at a fixed period of, for example, several seconds to several tens of seconds. Alternatively, narrow pulsed infrared light beams may be transmitted. Second
The detector shown in the figure can have an extremely compact configuration and can be incorporated into an existing light transmitting/receiving device. Note that the detection area of the transmission surface by this detector is extremely small, and there may be cases where the heater is not energized when it starts snowing or when snow or frost is sparsely deposited. However, as mentioned above, the light transmitter/receiver transmits light with an amount of light several tens to hundreds of times higher than the minimum required amount, so if there is sparse accumulation of snow or frost, it will assume that there is an intrusion and send out a cutoff signal. There are no false positives.

In addition to the optical beam warning device that issues the warning described in Figure 8, the present invention does not issue a warning when there is an intruder in the guarded area, but instead displays an alarm indicating that there is an intruder at a separate location, such as a monitoring center. Needless to say, this also applies to light beam warning devices that perform

[Effect of idea]

As explained above, the light beam warning device according to the present invention detects whether snow or frost has adhered to the surface through which the warning beam passes, and if it detects snow or frost, it operates only the heater at that point. As a result, power consumption can be reduced and temperature rise inside the aircraft can be prevented.

[Brief explanation of the drawing]

Figure 1 shows the control circuit for the heater, which is the main part of the present invention, Figure 2 is a schematic diagram of the detector for snow and frost on the aircraft body, and Figure 3 shows the aircraft body, heater, and transmitter in the light transmitting/receiving device. Figure 4 is a side view of the positional relationship between the optical device and the detector in Figure 2, Figure 4 is a front view of the relationship between the heater and light transmitter in Figure 3, and Figure 5 is the heater control circuit. Figure 6 shows another example of a snow and frost detector, Figure 7 shows another example of a snow and frost detector.
The figure shows an example of the use of a light beam warning device, and FIG. 8 is a diagram showing the internal configuration of the light transmitting/receiving device shown in FIG. 7. In the figure, 12 is a light transmitting and receiving device, 14 and 21 are the aircraft,
16 is a light receiver, 17 is a light transmitter, 22, 22' are light transmitting elements, 23, 23' are light receiving elements, 33 is a heater,
34 is a temperature switch, and 35 is a temperature fuse.

Claims (1)

[Scope of utility model registration request] A light beam warning device that detects that a warning light beam is interrupted and issues an alarm includes a light transmitting element and a light receiving element that are provided adjacent to a warning light transmitting surface that is in contact with the outside air and that are separate from those for the warning light beam. a detector for detecting snow, frost, etc. adhering to the transmitting surface using an element; a heater for heating the transmitting surface for the warning light beam; and energizing the heater in response to a signal from the detector. A light beam warning device characterized by comprising a circuit for controlling.