JPH0622187Y2 - Infrared passive sensor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to an improvement of an infrared passive sensor used for security alarms and automatic doors, which detects the presence of a person by a change in infrared rays. is there.

[Prior Art] In recent years, infrared passive sensors have been widely used in place of conventional photoelectric switches in automatic doors, antitheft alarms, and the like. This infrared passive sensor focuses infrared rays emitted from a human body or an animal with a lens to focus the light on the light receiving section, and detects the presence of an object such as an intruder by changing the amount of infrared rays detected by the light receiving section. Has become.

In addition, the sensitivity range of the conventional infrared passive sensor is determined for each sensor, and different sensitivity ranges are used depending on the use conditions. For example, FIGS. 3 and 4
As shown in the figure, the surface-passive infrared passive sensor 10 is used to watch a place far away from the infrared passive sensor, and the stereoscopic infrared passive sensor 20 is used to watch a wide area nearby. Was going to use.

In these infrared passive sensors 10 and 20, a light receiving portion 12 is arranged inside a semitransparent synthetic resin case 11, and a lens in which a plurality of Fresnel lenses are assembled is provided at one location on the surface of the case 11. The infrared ray from the outside is incident on the light receiving portion 12 through the lens, and the change in the amount of the infrared ray from the outside is detected. A larger Fresnel lens is mainly used as the surface warning type 10, and a larger Fresnel lens and more Fresnel lenses are mainly used as the three-dimensional warning type 20.

[Problems to be Solved by the Invention] However, the above-mentioned conventional infrared passive sensor has a drawback that infrared rays are incident from a portion of the case other than the Fresnel lens, so that a malfunction easily occurs. That is, as shown in FIG. 3 (A) and FIG. 4 (A), the infrared ray X emitted from a person or the like in a range other than the set sensitive range (unnecessary to be alert) is also sensitive. was there. In order to prevent such malfunction, it is possible to make the parts other than the Fresnel lens opaque, but the manufacturing process becomes complicated and the cost becomes high.

In addition, conventional infrared passive sensors require manufacturing equipment that can supply multiple types of products according to specifications.For users of infrared passive sensors, once the infrared passive sensor is installed, its sensitive range can be changed. There was also the problem that it was inconvenient because it could not be done.

The present invention has been made to solve such a problem, and an object thereof is to provide an infrared passive sensor capable of effectively preventing malfunction. Another object of the present invention is to provide a versatile infrared passive sensor which can be selectively used as a surface alert type and a three-dimensional alert type according to the purpose of use.

[Means for Solving the Problems] In the infrared passive sensor of the present invention, a second lens is provided in a portion of the case where the lens is not provided, which focuses incident light on the portion and collects it in a portion other than the light receiving portion. Is provided. Further, according to the present invention, the first lens is arranged at a plurality of positions spaced apart from each other in the circumferential direction of the case, and the case is provided rotatably in the circumferential direction with respect to the sensor body. It is also configured as a surface alert type that receives infrared rays from a range and a three-dimensional alert type that receives infrared rays from a wide range nearby.

[Operation] In the infrared passive sensor having the above configuration, since the infrared ray from the second lens is collected in a portion other than the light receiving portion, a malfunction is prevented. Further, by configuring the first lens as a surface warning type lens and a three-dimensional warning type lens respectively, it is possible to rotate the case and select a lens suitable for the purpose of use.

[Embodiment] An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. FIG. 1 is a side view showing an infrared passive sensor according to an embodiment. Reference numeral 1 in the figure denotes a sensor body. The sensor body 1 has a disk shape, and has a light receiving portion inside thereof, and an electric circuit for converting the amount of infrared rays incident on the light receiving portion into an electric signal and for monitoring a change in the magnitude of the electric signal (each. (Not shown) is incorporated. A case 2 is attached to the sensor body 1. The case 2 is made of transparent or translucent synthetic resin, and has a flat bottom portion 2a and an outer peripheral portion 2 having a convex curved surface shape.
It is formed like a bowl with b. And case 2
Are supported and attached to the sensor body 1 so as to be rotatable about the center line.

On the outer peripheral portion 2b of the case 2, a plurality of lenses (first lens, two in this embodiment) 3 and 4 which are equally spaced in the rotation direction thereof are formed. In addition, the lens 3,
The arrangement of 4 may be unequal intervals, or may be 3 or more. One lens 3 is a plurality of Fresnel lenses 3
a is assembled by compound eyes, and each Fresnel lens 3a is integrally formed with the case 2 by continuously forming a large number of concentric grooves on the inner peripheral surface of the case 2. There is. The size of each Fresnel lens 3a is relatively large. Therefore, the lens 3 is capable of condensing infrared rays emitted from a relatively distant narrow range and making the infrared rays enter the light receiving section, and the sensitive range is a surface alert type.

On the other hand, the other lens 4 is configured for three-dimensional security. That is, the lens 4 is configured by assembling the Fresnel lenses 4a ... In a compound eye shape like the lens 3, but the size of each Fresnel lens 4a is smaller than that of the lens 3 and a large number of lenses are provided. Has been. For this reason, the lens 4 can collect infrared rays emitted from a relatively wide range and enter the light receiving section, and the sensitive range is a three-dimensional alert type.

When the lenses are arranged at three or more places, the number and size of the lenses can be changed little by little so that the warning range can be changed stepwise.

A lens (first lens) 5 is formed on the bottom portion 2a of the case 2 adjacent to the lenses 3 and 4.
This lens 5 is for setting a sensitive range in the immediate vicinity of the infrared passive sensor, and is formed by connecting Fresnel lenses 5a of the same size and size in series.

Further, a second lens 6 is formed in a portion of the case 2 where the lenses 3, 4, and 5 are not formed (hatched portion in the drawing). The second lens 6 also has a Fresnel lens formed in the same manner as described above, but is configured so that the incident infrared rays are collected in a portion other than the light receiving portion.

In the infrared passive sensor having the above configuration, the lens 3
By directing the light beam toward the light receiving portion side, as shown in FIGS.
It is used as a surface alert type sensor as shown in. Also,
By rotating the case 2 and directing the lens 4 toward the light receiving portion, it is used as a three-dimensional alert type sensor as shown in FIGS. 4 (A) and 4 (B). Then, for example, while the infrared rays that have entered the lens 3 are focused and enter the light receiving section,
The infrared rays that have entered the second lens 6 are focused and collected in a portion other than the light receiving portion, so that they do not enter the light receiving portion. Therefore, malfunction can be effectively prevented.

Further, since one infrared passive sensor can be selectively used for the surface alert type and the three-dimensional alert type, the manufacturer only needs to have one type of manufacturing equipment. Therefore, the manufacturing cost can be reduced, and the user can appropriately change the sensitive range after attaching the infrared passive sensor, which is very convenient.

In the above embodiment, the lens is a Fresnel lens. However, the lens is not limited to this, and any kind of lens can be used as long as it can collect infrared rays. Further, in order to accurately reproduce the relative position between the lens and the case, both may be marked, or an uneven engaging portion may be formed on the contact surface portion of both.

[Advantages of the Invention] As described above, in the infrared passive sensor of the present invention, the second part of the case where the lens is not provided is used to focus the incident light to the part and collect it in the part other than the light receiving part. Since this lens is provided, malfunction can be effectively prevented. Further, the first lens is arranged at a plurality of positions spaced apart from each other in the circumferential direction of the case, and the case is provided rotatably in the circumferential direction with respect to the sensor main body. Since it is also configured with a surface alert type that receives the infrared ray and a three-dimensional alert type that receives infrared rays from a wide range nearby,
By rotating the case, it is possible to select a lens suitable for the purpose of use, and it is possible to achieve excellent effects such as a reduction in manufacturing cost.

[Brief description of drawings]

1 and 2 show an embodiment of the present invention.
FIG. 1 is a side view showing an infrared passive sensor, FIG. 2 is a plan view thereof, and FIGS. 3 (A) to 4 (B) are views for explaining a sensitive range of a conventional infrared passive sensor. FIG. 3 (A) is a side view showing a surface alert type infrared passive sensor and its sensitive range, and FIG. 3 (B) is the same (A).
FIG. 4A is a side view showing a three-dimensional alert infrared passive sensor and its sensitive range, and FIG. 4B is a view in the B direction of FIG. . 1 ... Sensor body, 2 ... Case, 3, 4, 5 ... Lens (first lens), 6 ... Second lens.

Claims (2)

[Scope of utility model registration request] 1. A sensor main body is provided with a light receiving portion and a case surrounding the light receiving portion, and a first portion provided in the case.
In the infrared passive sensor configured such that the infrared light that has passed through the lens is incident on the light receiving unit, the incident light to that portion is focused on a portion of the case where the lens is not provided, except for the light receiving unit. Second to collect in the part of
Infrared passive sensor, which is equipped with a lens. 2. The first lens is arranged at a plurality of positions spaced apart from each other in the circumferential direction of the case, and the case is provided rotatably in the circumferential direction with respect to the sensor main body, and the first lens is located far from the sensor body. The infrared passive sensor according to claim 1, wherein the infrared passive sensor is configured as a surface alert type that receives infrared rays from a narrow range and a three-dimensional alert type that receives infrared rays from a wide range that is near.