JPH0641158Y2 - Light-proof detector with drip-proof and anti-fog structure - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention is a drip-proof optical detector that separates a projector and a receiver to detect a change in an infrared pulse beam caused by an intruder or smoke to give an alarm. Regarding anti-fog structure.

[Prior Art] Conventionally, in this type of light beam detector, a light emitter and a light receiver are separately arranged, and an infrared pulse beam is emitted from the light emitter toward the light receiver to monitor between the light emitter and the light receiver. For example, the receiver detects the attenuation of the pulsed beam light when smoke from a fire flows into the space to issue a fire alarm, or the interception of the pulsed beam caused by an intruder crossing the surveillance space is detected by the receiver. I try to give a theft alarm.

[Problems to be Solved by the Invention] However, in such a conventional light beam detector, when it is installed in a place with high humidity, a place with a large temperature difference, etc. The inside or outside of the translucent cover using an acrylic plate or the like provided on the front surface of the light receiving lens is fogged or water droplets are attached, which causes a false alarm. Further, in the case of the lens-exposed type that does not have a light-transmitting cover, the inside or outside of the lens may become cloudy, or water droplets may adhere to the lens, causing a similar false alarm.

The present invention has been made in view of the above conventional problems, and provides a drip-proof and anti-fog structure for a light-beam detector that prevents fogging of optical members such as a translucent cover and a lens and adhesion of water droplets. The purpose is to

[Means for Solving the Problem] First, in the present invention, a light emitter and a light receiver are separately arranged, and a change in an infrared pulse beam projected from the light emitter due to an intruder or smoke is detected by the light receiver to give an alarm. Intended for light beam detectors.

In such a light beam type detector, in the drip-proof and anti-fog structure according to claim 1 of the present invention, the pulse beam transmitting portion in an optical member such as a light-transmitting cover and a lens provided in the light projector and / or the light receiver is A transparent heater member made of a transparent conductive film is provided at the surrounding position.

Further, in the drip-proof and anti-fog structure according to claim 2, a transparent heater member made of a transparent conductive film is provided on a portion of the optical member such as a light-transmitting cover and a lens in the projector and / or the receiver which transmits the pulse beam. .

[Operation] In the drip-proof and anti-fog structure of the light beam detector according to the present invention having such a configuration, the light-transmitting cover or the light-transmitting or light-receiving lens is heated by the heater member. Even if it is installed in a place with high humidity or a large temperature difference, high reliability can be obtained without causing fog or water droplets on the inside of the translucent cover or lens. Further, in the present invention, since the transparent conductive film capable of reducing the film thickness is used as the heater member, it is possible to prevent the transparency of the infrared pulse beam from being deteriorated,
Further, it is possible to prevent the size from becoming large and the weight from becoming heavy. As a result, even if a transparent heater member is used, the sensitivity does not deteriorate, so even a light beam type detector with a light emitter and a light receiver arranged separately can reliably detect intruders and smoke, and it is also compact and lightweight. Can be realized.

Further, according to the present invention, by providing a transparent heater member made of a transparent conductive film at a position surrounding the pulse beam light transmitting portion of the optical member, it is possible to further prevent deterioration of the transparency of the infrared pulse beam. Further, by providing a transparent heater member made of a transparent conductive film in the transparent portion itself, the light transparent portion can be heated more uniformly, and as a result, clouding or water droplets are generated in the transparent portion. Can be prevented.

[Embodiment] FIG. 1 is an assembly exploded view showing an embodiment of the present invention by taking a light ray detector for smoke detection as an example.

In FIG. 1, reference numeral 1 denotes a detector main body, which constitutes a projector or a light receiver. A light projecting or light receiving lens 2 is incorporated in the detector body 1, and a light projecting element or a light receiving element is incorporated behind the lens 2 as will be described later.

A translucent cover 4 made of an acrylic plate is attached to the opening 2 of the detector body 1 via a rubber packing 3 to protect the lens 2 built in the detector body 1.

In the embodiment of FIG. 1, the heater member 5 is installed inside the translucent cover 4 using an acrylic plate.

FIG. 2 shows the heater member 5 provided on the translucent cover 4 of FIG.

In FIG. 2, the heater member 5 has a transparent heater portion 6 made of a transparent conductive film obtained by vapor-depositing an indium tin oxide thin film on the surface of a transparent polyester film, and a pair of electrodes 7 is vapor-deposited above and below the transparent heater portion 6. Then, the lead wire 8 is led out from the electrode 7.

With the heater member 5 having such a structure, for example, when a DC voltage of 24 V is applied between the electrodes 7, a heating efficiency of about 2.3 W is obtained.

In addition to the vapor deposition of indium tin oxide on the surface of a polyester film, tin oxide or metal ultrafine particles may be dispersed in a resin and coated on the surface of the film to form a transparent conductive film. Part 6 can be obtained.

FIG. 3 is a sectional view showing the internal structure of the embodiment shown in FIG. 1, in which the lens 2 is supported in the detector main body 1, and the lens 2
A printed circuit board 9 is provided behind the optical element 10, and an optical element 10 is arranged on the printed circuit board 9 facing the optical axis center of the lens 2. If the optical element 10 is a projector, an infrared light emitting diode that emits an infrared pulse beam. Is used, and if it is a light receiver, an infrared photodiode is used.

A translucent cover 4 using an acrylic plate is installed on the front surface of the lens 2 through a rubber packing 3, and a heater member 5 having the structure shown in FIG. 2 is mounted inside the translucent cover 4. Therefore, the heater member 5 is provided at the portion of the translucent cover 4 where the infrared pulse beam 11 is transmitted.

In the embodiment shown in FIGS. 1 to 3, the transparent cover 4 is always kept at a predetermined temperature by energizing the heater member 5 mounted inside the transparent cover 4 when the detector is installed. The temperature of the translucent cover 4 itself, which is maintained in a heated state and is directly exposed to changes in the outside air even when installed in a place with high humidity or a large temperature difference, is in a stable state, The inside or outside of the translucent cover 4 is not fogged or water droplets are not attached, and stable monitoring operation can be performed without causing misinformation due to fog or water droplets.

FIG. 4 is an explanatory view showing another embodiment of the heater member used in the present invention.

FIG. 4 (a) shows another heater member 5a used in the present invention, which includes a transparent heater portion 6a made of a transparent conductive film obtained by depositing an indium tin oxide thin film on the surface of a ring-shaped polyester film. The ring-shaped transparent heater portion 6a is separated at one place to provide a pair of electrodes 7 and lead wires 8 are drawn to the outside.

FIG. 4 (b) shows a state where the heater member 5a shown in FIG. 4 (a) is attached to the translucent cover 4, and the heater member 5a is attached to the transmissive portion of the infrared pulse beam in the translucent cover 4. It is characterized in that it is provided in a surrounding position.

As shown in FIG. 4, the translucent cover 4 used for the detector
When the heater member 5a is provided so as to surround the transparent portion of the infrared pulse beam in FIG. 4, it is not always necessary to use the transparent heater portion 6a as the heater member 5a as shown in FIG. 4 (a). Even a normal heater structure in which a nichrome wire or the like is wound around a ring-shaped insulating material can be used as it is. In particular, it is preferable to provide the heater member at a position surrounding the transparent portion of the infrared pulse beam because the transmittance is not deteriorated as compared with the transparent heater portion made of a transparent conductive film at the transparent portion.

FIG. 5 is a sectional view showing another embodiment of the present invention, which is for a lens exposure type.

In the lens exposure type detector shown in FIG. 5, the heater member 5 is assembled behind the lens 2 provided in the detector main body 1. As the heater member 5, a transparent heater portion 6 is provided as shown in FIG. 2 so that the heater member 5 is arranged at the transmission portion of the infrared pulse beam 11, or a ring-shaped transparent heater portion as shown in FIG. Have 6a,
Any of them may be provided so as to surround the transmitting portion of the infrared pulse beam 11.

Further, the heater member 5 may be arranged apart from the lens 2 as shown, or may be provided in contact with the lens 2 or a supporting member thereof.

Even in the embodiment shown in FIG. 5, since the lens 2 exposed to the outside is always kept at a predetermined temperature by the heater member 5 provided inside, it is possible to use it in a place with high humidity or a place with a large temperature difference. In addition, it is possible to reliably prevent the inside or outside of the lens 2 from becoming cloudy or water droplets to be attached to cause a false alarm.

FIG. 6 is an exploded view showing another embodiment of the present invention, taking a photodetector for theft detection as an example.

In FIG. 6, reference numeral 1 is a detector main body, which is screwed and fixed to a mounting plate 14 fixed to a pole 12 by a U-shaped bolt 13 with a screw 15. A lens 16 is provided on the front surface of the detector body 1, and an optical element (light emitting element or light receiving element) is built in behind the lens 16. A cover 17 is attached to the front surface of the detector body 1, and a translucent cover 18 using a semi-cylindrical acrylic plate is provided at a portion of the cover 17 facing the lens 16, and an inner side of the translucent cover 18 is provided. As indicated by the dashed line in
For example, the heater member 5 having the transparent heater portion 6 is incorporated in the same infrared light beam transmitting portion shown in FIG.

Even in the case of the light detector for detecting theft shown in FIG. 6, since the translucent cover 18 is constantly heated and maintained at the predetermined temperature by the heater member 5 provided inside, a slightly humid place and a slight temperature difference. Even when installed in a severe environment, especially when installed outdoors to detect theft, the inside or outside of the translucent cover 18 does not become fogged or water drops adhere, and stable monitoring operation that does not cause false alarms is performed. Can be done.

Of course, in the theft-type photodetector shown in FIG. 6, a heater member may be provided so as to surround the transparent portion of the infrared pulse beam as in the case shown in FIG.

Further, some of the photodetectors for theft detection shown in FIG. 6 have a structure in which the transparent cover 18 itself is provided with a Fresnel lens, so that the transparent cover and the lens are integrated. A heater member may be provided in the same manner as the converted one. Further, although the lens is used as the optical system in the above-described embodiment, an optical system that collects light using a mirror may be used.

[Advantage of the Invention] As described above, according to the present invention, an optical member including a light-transmitting cover or a lens for projecting light or receiving light provided in the photodetector is heated by the heater member to be predetermined. Because the temperature is maintained, it does not fog or adhere to the inside or outside of the translucent cover or lens even if it is installed in a place with high humidity or a large temperature difference. False alarms can be prevented and high reliability can be obtained. Further, in the present invention, since the transparent conductive film capable of reducing the film thickness is used as the heater member, it is possible to prevent the transparency of the infrared pulse beam from deteriorating and to increase the size. It can be prevented from becoming heavy. As a result, the sensitivity does not deteriorate even if a transparent heater member is used, so even an optical ray type detector in which a light emitter and a light receiver are separately arranged can reliably detect an intruder or smoke, and is small and lightweight. Can be realized.

Further, according to the present invention, by providing a transparent heater member made of a transparent conductive film at a position surrounding the pulse beam light transmitting portion of the optical member, it is possible to further prevent deterioration of the transparency of the infrared pulse beam. Further, by providing a transparent heater member made of a transparent conductive film in the transparent portion itself, the light transparent portion can be heated more uniformly, and as a result, clouding or water droplets are generated in the transparent portion. Can be prevented.

[Brief description of drawings]

1 is an exploded view showing an embodiment of the present invention for smoke detection; FIG. 2 is an explanatory view of the heater member of FIG. 1; FIG. 3 is a sectional view of FIG. 1; FIG. 5 is an explanatory view showing another embodiment of the heater member used in the present invention; FIG. 5 is a sectional view showing an embodiment of a lens exposure type; FIG. 6 is an exploded view showing an embodiment for monitoring theft. is there. 1: Detector body 2, 16: Lens (for emitting or receiving light) 3: Rubber packing 4,18: Translucent cover 5, 5a: Heater member 6, 6a: Transparent heater section 7: Electrode 8: Lead wire 9: Printed circuit board 10: Optical element (transmissive element or light receiving element) 11: Infrared pulse beam

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Claims (4)

[Scope of utility model registration request] 1. A light type detector in which a light emitter and a light receiver are separately arranged, and the infrared light beam projected from the light emitter is detected by the light receiver to detect a change due to an intruder or smoke. A light-transmitting cover provided on the light-emitter and / or the light-receiver,
A drip-proof and anti-fog structure for a light beam type detector, characterized in that a transparent heater member made of a transparent conductive film is provided at a position surrounding the pulse beam light transmitting portion of an optical member such as a lens. 2. A light beam type detector in which a light emitter and a light receiver are separately arranged, and the infrared light beam projected from the light emitter is detected by the light receiver to detect a change due to an intruder or smoke. A translucent cover provided on the light projector and / or the light receiver,
A drip-proof and anti-fog structure for a light beam type detector, wherein a transparent heater member made of a transparent conductive film is provided on the pulse beam light transmitting portion of an optical member such as a lens. 3. The photodetector according to claim 1, wherein the transparent heater member is made of a transparent polyester film and a transparent conductive film obtained by depositing a thin film of indium tin oxide or a metal on the surface of the transparent polyester film. Drip-proof and anti-fog structure. 4. The transparent heater member is made of a transparent conductive film, which is formed by dispersing ultrafine particles of tin oxide or metal in a resin on the surface of a transparent polyester film and coating the transparent conductive film. The drip-proof and anti-fog structure of the light beam detector described in 2.