JP3509583B2 - Cover for infrared sensor - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an infrared sensor cover, and more particularly to an infrared sensor cover having excellent infrared transparency.

[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 provided in order to secure a desired detection area for the purpose of widening the detection range. Lenses are often used for.
A high-density polyethylene resin is used for this lens in terms of infrared transparency.

In general, the infrared sensor is rarely used by itself, and is used by being attached to a part of a structure such as a luminaire that requires the infrared sensor. In this case, the lens is often used with the lens exposed to the outside so that there is no attenuation of infrared rays other than the lens.

[0004]

However, when the lens is exposed to the outside, the design harmony with the main body of the structure incorporating the infrared sensor cannot be achieved and the overall design is impaired. there were.

Also, in the case of a lighting fixture with an infrared sensor,
The material used for the structure is often 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 design, infrared transmission There is a problem that the sensitivity of the infrared sensor is lowered due to the extreme attenuation of the rate.

Further, a method of covering only the front surface of the lens with a cover made of high-density polyethylene resin can be considered,
Even in this case, the infrared transmittance decreases. If you reduce the thickness of the cover to suppress this decrease as much as possible,
The cover made of high-density polyethylene resin has a transparent portion, which makes it impossible to satisfy the shielding property. Also,
In the case of a cover made of high-density polyethylene resin, a slight difference in appearance (gloss, color, etc.) occurs due to the difference in material from the structure body, and it is often difficult to achieve a design harmony.

On the other hand, in the case where the detection range is limited to some extent, such as an infrared sensor used for an automatic door or an automatic flush toilet, a complicated shape such as a lens is necessary for condensing infrared rays. Instead, a flat simple cover (panel) is often used in front of the infrared detection element, and the cover has a glass substrate surface with a filter that transmits only the infrared wavelength range emitted by the human body. What was formed into a film by surface treatment was used.

However, in this case, since the material to be formed is a black-based material, the cover itself can only be 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 an infrared sensor cover excellent in infrared transmittance without impairing the designability of the structure body. To do.

[0010]

The invention according to claim 1 is
A cover for covering the infrared sensor, Ri Na to form a hole for a plurality of infrared transmitting follows diameter 0.4mm on an optical axis of the detection beam, the cross-sectional area of the plurality of holes for infrared transmission, red
Cross section so that the outside wire sensor side is larger than the outside
It is characterized by having an inclination along the direction .

According to a second aspect of the present invention, in the first aspect of the invention, the area of the plurality of infrared transmitting holes is 1
It is characterized in that it is formed so as to have an occupancy rate of 40% to 70% with respect to the cross section of one detection beam.

[0012]

The invention according to claim 3 is characterized in that, in the invention according to claim 1 or 2 , it is made of a material having a low infrared transmittance.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION An example of an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic cross-sectional view showing a state where an infrared sensor cover according to an embodiment of the present invention is used as a cover (glove) for a lighting fixture. 1
Is a cover of a lighting fixture and is formed of milky white acrylic or the like. Reference numeral 2 denotes an infrared sensor, which is supported by the support member 3 from the 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 detection element 21 such as a pyroelectric element as shown in FIG. The lens 22 is composed of, for example, a plurality of convex lenses to form a plurality of spot-like detection regions (detection beams).

In the cover 1, the infrared transmitting region 10 corresponding to the optical axes of the plurality of detection beams 23 of the infrared detection element 21, that is, the portion intersecting the optical axes of the plurality of detection beams 23 is shown in FIG. A plurality of beam spots 11 including a plurality of holes 12 for transmitting infrared rays are formed. Therefore, as shown in FIG. 4, a plurality of beam spots 11 are formed in the infrared transmitting region 10 in the substantially central portion of the cover 1.

The hole 12 has a diameter of 0.4 mm or less. The number of holes 12 is set so 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, inconsistency in design with the structure due to the 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 infrared transmittance 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 existence of the hole 12 is not conspicuous, and the design of the lighting apparatus as a whole is not deteriorated.

Furthermore, if the number of holes 12 is set so that the occupancy rate is 40% to 70% with respect to the cross section of one detection beam 23, infrared rays in a range that does not hinder the sensor performance. While ensuring the transmittance, the presence of the holes 12 is not conspicuous, and the design of the lighting apparatus as a whole is not deteriorated. Further, since the occupancy rate does not become too large, there is no requirement 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 the beam spot of the cover according to the main part of the present invention. In the present embodiment, the diameter of the hole 12 is formed so as to be inclined along the cross-sectional direction of the cover 1 so that the infrared sensor 2 side is large and the outside is small.

According to this embodiment, since the diameter of the hole 12 is larger on the infrared sensor 2 side and smaller on the outer side, the existence of the hole 12 is less noticeable from the outer side of the cover 1 and the cover is less visible. It is possible to reduce the shielding of infrared rays by the cover 1 that occurs due to a mounting error of 1 or a slight positional deviation.

In the above embodiment, even if the cover 1 is made of a material having a small infrared ray transmittance, 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 other structures such as a lens cover for a separate transmitter. It goes without saying that the same effect is achieved.

[0023]

As described above, according to the first aspect of the invention, the cover for covering the infrared sensor has a diameter of 0.4 mm.
Since a plurality of holes for transmitting infrared rays of mm or less are formed on the optical axis of the detection beam, it is possible to transmit infrared rays through the holes regardless of the cover made of any material. , Without compromising the design with the structure body,
We were able to provide a cover for infrared sensors with excellent infrared transparency. Moreover, the cross-sectional area of the plurality of infrared transmitting holes,
Cross section so that the infrared sensor side is larger than the outside
Since it has a slope along the direction, from the outside of the cover
The presence of holes is less noticeable and the cover is attached
Infrared rays generated by the cover caused by errors and subtle displacement
The shielding can be reduced.

According to the invention described in claim 2, in the invention described in claim 1, 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 occupancy rate of 1, the infrared transmittance of the range that does not hinder the sensor performance is ensured, while the presence of the holes is not conspicuous, and the designability of the entire structure may be deteriorated. Disappear. In addition, since the occupation ratio does not become too large, there is no requirement for high drilling accuracy, and the hole 2
Therefore, the strength of the portion where the is present does not decrease.

According to the third aspect of the present invention, in the first or second aspect of the invention, the cross-sectional area of the plurality of infrared transmitting holes is larger on the infrared sensor side than on the outer side. By providing an inclination along the cross-sectional direction, the presence of the holes is less noticeable from the outside of the cover, and the shielding of infrared rays by the cover caused by a cover mounting error or a slight positional deviation can be reduced.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing a state where an infrared sensor cover 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 above.

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

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

It is a schematic view showing a cross section of a main part of the cover infrared sensor according to the present invention; FIG.

[Explanation of symbols]

1 Infrared sensor cover 2 infrared sensor 3 Support members 4 Base member 10 Infrared transmission area 11 beam spot 12 holes 21 Infrared detector 22 lens 23 Detection beam

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-60-95379 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G01J 1/00-1/60 G01J 5 / 00-5/62 G01V 8/10-8/26 G08B 13/18-13/196

Claims (3)

(57) [Claims] 1. A cover for covering the infrared sensor, Ri Na to form a hole for a plurality of infrared transmitting follows diameter 0.4mm on an optical axis of the detection beam, said plurality of holes for infrared transmission
The cross-sectional area of the infrared sensor side is larger than the outside
As described above, the infrared sensor cover is characterized by being inclined along the cross-sectional direction . 2. The area of the plurality of infrared transmitting holes is
The infrared sensor cover according to claim 1, wherein the cross section of one detection beam is formed to have an occupancy rate of 40% to 70%. 3. A process according to claim 1 or claim 2 infrared sensor cover, wherein the configured at a low material having infrared transmittance.