JP2000136963A - Cover for infrared sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a cover whose transmittance to infrared rays is superior without spoiling the designing property of a structure body by forming a plurality of holes, for infrared transmission, whose diameter is at a specific value or lower on the optical axis of a sensing beam. SOLUTION: An infrared sensor 2 is covered with a cover 1. Thereby, the disharmony of a design with a structure body due to the exposure of the infrared sensor 2 is prevented. Since a beam spot 11 which is composed of holes is formed on the optical axis of a sensing beam 23, the transmittance of infrared rays is enhanced, and a human body in a desired sensing range can be detected surely. In addition, since the diameter of every hole is set at 0.4 mm or lower, the existence of every hole is not noticeable, and the designing property of a luminaire as a whole is not lowered. In addition, when the number of holes is set in such a way that an occupation rate is 40 to 70% with reference to the cross section of one sensing beam 23, the existence of the holes 12 is not noticeable while the transmittance of infrared rays in a range which does not spoil the performance of the sensor is being ensured, and the designing property of the luminaire as a whole is not lowered.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a cover for an infrared sensor, and more particularly to a cover for an infrared sensor having excellent infrared transmittance.

[0002]

2. Description of the Related Art Conventionally, as a part for an infrared sensor such as a human body detection sensor, a front surface of an infrared detection element such as a pyroelectric element is required to secure a desired detection area in order to widen a detection range. A lens is often used.
The lens is made of high-density polyethylene resin from the viewpoint of infrared transmission.

In general, an infrared sensor is rarely used by itself, but is used by being attached to a part of a structure such as a lighting fixture or the like that requires the infrared sensor. In this case, the lens is often used in a state where the lens is exposed to the outside so that infrared light is not attenuated outside the lens.

[0004]

However, if the lens is exposed to the outside, there is a problem that the design is not harmonized with the structure body incorporating the infrared sensor, and the overall design is impaired. there were.

In the case of a lighting fixture with an infrared sensor,
In many cases, the material used for the structure is a plastic that hardly transmits infrared rays, such as ABS and acrylic, and if the front surface of the lens is covered with the structure body to improve the design, infrared rays will be transmitted. There has been a problem that the sensitivity of the infrared sensor is reduced due to the extreme attenuation of the rate.

Further, a method of covering only the front surface of the lens with a high-density polyethylene resin cover is also conceivable.
Even in this case, a decrease in the infrared transmittance occurs. If the thickness of the cover is reduced to minimize this decrease,
In the case of a cover made of high-density polyethylene resin, a transparent part occurs, and the shielding property cannot be satisfied. Also,
In the case of a cover made of high-density polyethylene resin, a slight shift in the appearance texture (gloss, color, etc.) occurs due to the difference in material from the structure body, and in many cases, design harmony is not achieved.

On the other hand, when the detection range is limited to a certain extent, such as an infrared sensor used for an automatic door or an automatic flush toilet, a complicated shape such as a lens is required to collect infrared rays. Instead, for example, a flat simple cover (panel) is often used on the front surface of the infrared detecting element, and the cover has a filter on the glass substrate surface that transmits only the infrared wavelength range emitted by the human body. What was formed by surface treatment was used.

However, in this case, since the material to be formed becomes a black-based material, the cover itself can be made only a black-based material. It was impossible to ensure harmony.

The present invention has been made in view of the above points, and an object of the present invention is to provide a cover for an infrared sensor having excellent infrared transmittance without impairing the design of the structure body. Is to do.

[0010]

According to the first aspect of the present invention,
A cover for covering the infrared sensor, wherein a plurality of holes for transmitting infrared rays having a diameter of 0.4 mm or less are formed on the optical axis of the detection beam.

According to a second aspect of the present invention, in the first aspect of the invention, the area of the plurality of holes for transmitting infrared rays is one.
It is characterized in that it is formed so as to have an occupancy of 40% to 70% with respect to the cross section of one detection beam.

According to a third aspect of the present invention, in the first or second aspect of the present invention, the cross-sectional area of the plurality of holes for transmitting infrared rays is set to be larger on the infrared sensor side than on the outside. It is characterized by having an inclination along the direction.

According to a fourth aspect of the present invention, in any one of the first to third aspects of the present invention, the display device is made of a material having a low infrared transmittance.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic sectional view showing a state where a cover for an infrared sensor according to one embodiment of the present invention is used as a cover (glove) of a lighting fixture. 1
Is a cover of the lighting equipment, and is formed of milk-white acrylic or the like. Reference numeral 2 denotes an infrared sensor, which is supported by a support member 3 from a base member 4 in the cover 1. As shown in FIG. 2, the infrared sensor 2 is used by installing a lens 22 made of high-density PE or the like on the front surface of an infrared detecting element 21 such as a pyroelectric element for the purpose of detecting a human body. The lens 22 is composed of, for example, a plurality of convex lenses in order to form a plurality of spot-like detection areas (detection beams).

FIG. 3 shows an infrared transmitting area 10 of the cover 1 corresponding to the optical axes of the plurality of detection beams 23 of the infrared detecting element 21, that is, a portion intersecting with the optical axes of the plurality of detection beams 23. A plurality of beam spots 11 including a plurality of holes 12 for transmitting infrared light are formed. Therefore, as shown in FIG. 4, a plurality of beam spots 11 are formed in the infrared transmission area 10 substantially at the center of the cover 1.

The hole 12 has a diameter of 0.4 mm or less. The number of holes 12 is such that the occupation ratio is 40% to 70% with respect to the cross section of one detection beam 23.

According to the present embodiment, by covering the infrared sensor 2 with the cover 1, design inconsistency with the structure due to exposure of the infrared sensor 2 is prevented, and the hole 12 is formed on the optical axis of the detection beam 23. Since the beam spot 11 is formed, the transmittance of infrared rays is improved, and the human body can be reliably detected in a desired detection range regardless of the material of the cover 1. Further, since the diameter of the hole 12 is 0.4 mm or less, the presence of the hole 12 is not conspicuous, so that the design of the entire lighting fixture does not deteriorate.

Furthermore, if the number of holes 12 is set so that the occupancy is 40% to 70% with respect to the cross section of one detection beam 23, infrared rays in a range that does not hinder sensor performance can be obtained. While ensuring the transmittance, the presence of the holes 12 is not noticeable, and the design of the lighting fixture as a whole is not degraded. In addition, since the occupation ratio does not become too large, there is no need for high drilling accuracy and the strength of the portion where the holes 12 are present does not decrease.

FIG. 5 is a schematic view showing a cross section of a beam spot on a cover according to another embodiment of the present invention. In the present embodiment, the diameter of the hole 12 is larger on the infrared sensor 2 side,
The cover 1 is formed so as to be inclined along the cross-sectional direction of the cover 1 so that the outside becomes smaller.

According to the present embodiment, the diameter of the hole 12 is larger on the infrared sensor 2 side and smaller on the outside, so that the presence of the hole 12 from the outside of the cover 1 is less noticeable, and It is possible to reduce the shielding of infrared rays by the cover 1, which is caused by the mounting error of 1 and a slight displacement.

In the above embodiment, even if a material having a low infrared transmittance is used as the material of the cover 1, there is no problem because infrared rays are transmitted through the holes 12.

In the above embodiment, the case where the infrared sensor cover 1 is used as a cover (glove) of a lighting fixture has been described. However, the infrared sensor cover 1 may be used for another structure such as a lens cover for a separate transmitter. Needless to say, the same effect is achieved.

[0023]

As described above, according to the first aspect of the present invention, the cover for covering the infrared sensor has a diameter of 0.4 mm.
Because a plurality of holes for transmitting infrared rays of not more than mm are formed on the optical axis of the detection beam, no matter what cover is used, infrared rays can be transmitted through the holes. Thus, it was possible to provide a cover for an infrared sensor having excellent infrared transmittance without impairing the design with the structure body.

According to the second aspect of the present invention, in the first aspect of the present invention, the area of the plurality of holes for transmitting infrared rays is 40% to 70% with respect to the cross section of one detection beam.
If it is formed so as to have an occupation ratio of, it is possible to reduce the design of the entire structure without making the presence of holes noticeable, while ensuring infrared transmittance in the range that does not hinder sensor performance. Disappears. Further, since the occupation ratio does not become too large, there is no demand for high drilling accuracy, and the hole 2
There is no decrease in the strength of the portion where exists.

According to the third aspect of the present invention, in the first or second aspect of the present invention, the cross-sectional area of the plurality of holes for transmitting infrared rays is made larger on the infrared sensor side than on the outside. If the inclination is provided along the cross-sectional direction, the presence of the holes becomes less noticeable from the outside of the cover, and it is possible to reduce the shielding of the infrared rays by the cover due to a mounting error of the cover or a slight displacement.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a state in which a cover for an infrared sensor according to an embodiment of the present invention is used as a cover (glove) of a lighting fixture.

FIG. 2 is an enlarged view of a main part according to the first embodiment.

FIG. 3 is an enlarged view of a beam spot according to the embodiment.

FIG. 4 is a plan view of the infrared sensor cover of FIG. 1;

FIG. 5 is a schematic view showing a cross section of a main part of a cover for an infrared sensor according to another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Infrared sensor cover 2 Infrared sensor 3 Support member 4 Base member 10 Infrared transmitting area 11 Beam spot 12 Hole 21 Infrared detecting element 22 Lens 23 Detection beam

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Masao Yamaguchi 1048 Kazuma Kadoma, Kadoma-shi, Osaka F-term in Matsushita Electric Works Co., Ltd.

Claims (4)

[Claims] A cover for covering an infrared sensor, wherein a plurality of holes for transmitting infrared rays having a diameter of 0.4 mm or less are formed on the optical axis of a detection beam. 2. The area of the plurality of infrared transmitting holes,
2. The infrared sensor cover according to claim 1, wherein the cover is formed so as to have an occupation ratio of 40% to 70% with respect to a cross section of one detection beam. 3. The cross-sectional area of the plurality of holes for transmitting infrared rays is larger on the infrared sensor side than on the outside.
3. The infrared sensor cover according to claim 1, wherein the cover is inclined along a cross-sectional direction. 4. The infrared sensor cover according to claim 1, wherein the cover is made of a material having a low infrared transmittance.