JPH0350470Y2 - - Google Patents

Description

[Detailed explanation of the invention] (a) Industrial application field This invention detects the difference between the infrared light flux emitted from a moving object such as a human body and the infrared light flux emitted from the background such as the floor of a building. This invention relates to an infrared moving object detection device that detects and controls the opening and closing of automatic doors and the operation of security alarm systems.

(b) Conventional technology All objects at temperatures above absolute zero (-273°C) emit infrared rays corresponding to their temperature, but human bodies and buildings at room temperature emit far infrared rays with a wavelength of around 10 μm. ing. An infrared moving object detection device sets a predetermined detection area on the floor of a building, etc., and constantly monitors infrared rays emitted from this detection area using an optical system. It is configured to detect fluctuations in infrared light flux caused by an object such as a human body entering the detection area, and issue a signal to open an automatic door or a signal to trigger a security alarm system. be.

Incidentally, there are various environments in which automatic doors and security alarm devices are installed, and it is necessary to adjust the detection area according to the installation conditions. For example, in the case of automatic doors,
Assuming that the same detection area is set for single-door and double-door doors, in the case of single-door doors, the surrounding area other than the door opening will also be monitored, so third parties who do not intend to use automatic doors will be monitored. There was a possibility that someone could be detected. Therefore, in the case of a single-swinging door, it was necessary to reduce the detection area and make adjustments so that only the front side of the door opening was monitored.

(c) Problems to be solved by the invention In conventional infrared moving object detection devices,
For example, as in Japanese Utility Model Application No. 57-166111, a reflecting mirror is used in the optical system, and a shutter with low reflectance is provided between the reflecting mirror and the infrared detecting element to adjust the detection area. However, with this configuration, the positional relationship between the shutter drive lever and the detection area is reversed left and right, which often leads to situations where the shutter is set in the opposite direction and readjusted during construction.

In addition, in conventional devices that use a condenser lens in the optical system, the detection area is adjusted by attaching a film that blocks infrared rays to the front of the condenser lens that monitors unnecessary detection areas. Ta. However, when an infrared moving object detection device is used as a sensor of a security alarm system, for example, this method is not preferable because the security area may be easily detected from the outside.

(D) Purpose This invention was created in view of the above, and is an infrared moving object detection device using a condensing lens, in which there is no risk of the detection area being detected from the outside, and there is no risk of erroneous operation when adjusting the detection area. The present invention aims to provide an infrared type moving object detection device that does not require any prior art.

(e) Means for solving the problem The infrared moving object detection device according to this invention is
Between multiple condensing lenses that condense the infrared light flux emitted from the detection area and an infrared detection element that converts the incident infrared light flux into an electrical signal according to the amount of variation in the infrared light flux. A pair of shutter devices are provided, each of which is located at a shutter body and which blocks the optical path of one or more infrared light beams when closed. The adjustment lever engages with a pin provided between the proximal end and the distal end, is linearly displaced, and rotates the shutter body via this pin, and the linear adjustment lever of the pair of left and right drive levers It is characterized by being configured to adjust the detection area by movement.

(f) Examples The present invention will be explained in detail below based on the drawings.

FIG. 2 is a diagram showing a conventional device using a reflector in the optical system, in which the infrared light flux emitted from a predetermined detection area is reflected and focused by the reflector 1, and the pyroelectric detector,
The light enters an infrared detection element 2 such as a thermistor, bolometer, or thermoelectric stack. The detection area is adjusted by opening and closing the shutter 3, but as is clear from the figure, the positional relationship between the shutter 3 and the detection area is reversed left and right, so there is a drawback that it is easy to make operational errors. Was.

FIG. 1 shows an embodiment of the optical system of an infrared moving object detection device according to the present invention, in which an infrared light beam condensed by a condenser lens 4 enters an infrared detection element 2. In FIG. The pair of left and right shutter devices each include a shutter body 3, a fulcrum 5 that rotatably supports the shutter body 3 at its base end, a pin 7 implanted between the tip and base end of the shutter body 3, and a drive lever 6 that engages with the pin 7 and is linearly movable as shown by the arrow in the figure.

With this configuration, by linearly displacing one of the drive levers 6, the pin 7 is pressed and the shutter body 3 rotates around the fulcrum 5, and the infrared detection element 2 is moved through the condenser lens 4. The area of infrared light beam incident on the sensor is restricted, and the detection area can be adjusted.

What is particularly noteworthy about this configuration is that the detection area on the same side as the displaced drive lever is adjusted, and the detection area changes by linear lever operation, making it easy to adjust the detection area. This can be done while accurately grasping both directionally and quantitatively. Another point to note is that
The shutter device is located behind the optical system (condensing lens) relative to the object to be detected, which makes it difficult to set the detection area visually from the outside.
Another advantage is that the entire shutter mechanism can be made compact without protruding from the light receiving area of the optical system. At this time, the condenser lens 4
If the locking position of the drive lever 6 is appropriately set in advance according to the optical path of the infrared light beam condensed by the
It would be more effective in practice.

(g) Effects of the invention As detailed above, according to the infrared moving object detection device according to the invention, when adjusting the detection area, the positional relationship between the shutter adjustment drive lever and the detection area is in the same direction, so the detection This prevents operational errors from occurring when adjusting the area. Moreover, since the drive lever is linearly displaced, quantitative adjustment of the detection area can be grasped almost accurately intuitively. Furthermore, even if the drive lever is displaced linearly, the displacement is transmitted to the shutter body via a pin provided between the pivot point at the base end and the tip. The amount of displacement is magnified and reflected in the amount of displacement of the shutter body, and by installing the shutter mechanism behind the optical system, the detection area can be significantly changed without protruding beyond the light receiving surface of the optical system. In addition to the fact that this mechanism is provided, the device can be made compact without increasing its size.
Furthermore, since the shutter is placed inside a condensing lens made of opaque synthetic resin that cannot be seen from the outside, this design provides superior safety when used as a sensor for a security alarm system. The effect is truly remarkable.

[Brief explanation of the drawing]

FIG. 1 shows an embodiment of the optical system of an infrared moving object detection device according to the present invention, and FIG. 2 shows an optical system of a conventional infrared moving object detection device using a reflecting mirror. 1...Reflector, 2...Infrared detection element, 3...
Shutter, 4...Condensing lens.

Claims (1)

[Scope of utility model registration request] In a device that uses an optical system to monitor the infrared light flux emitted from a predetermined detection area, and detects the intrusion of an object into the detection area by detecting changes in the infrared light flux, the infrared light flux emitted from the detection area is detected. Between a plurality of condensing lenses that condense infrared light flux, and an infrared detection element that converts the incident infrared light flux into an electrical signal according to the amount of variation thereof, one lens is located outside the infrared light flux when open, and one when closed. A pair of shutter devices are provided for blocking the above infrared light flux, and each of the shutter devices includes a shutter body whose base end is rotatably supported by a fulcrum, and a shutter body provided between the base end and the tip of the shutter body. An infrared moving object detection device comprising an adjustment lever that engages with a pin and is linearly displaced to rotate the shutter body via the pin.