JPH07280641A - Infrared sensor - Google Patents

Abstract

PURPOSE:To provide a high resolution infrared sensor being used for observing the position, surface temperature, etc., of an object. CONSTITUTION:The infrared sensor comprises a plurality of sensor section 2 mounted on a plane substantially perpendicular to the incident direction of infrared rays 4 in order to sense the infrared rays 5 passed through a chopper 3, means 6 for rotating the sensor sections 2 about a rotational axis extending substantially perpendicularly to the incident direction of infrared rays 5, and means 1 for inclining the plate mounting the sensor sections 2. This infrared sensor realizes observation of plane distribution of temperature variation with resolution two or more times higher as compared with a conventional sensor.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pyroelectric infrared sensor which is used to detect infrared rays emitted from an object in a night-vision camera device, an air conditioner, etc. and observe the position, surface temperature, etc. of the object. Regarding the device.

[0002]

2. Description of the Related Art An infrared sensor device that catches infrared rays emitted by the human body and instantly finds out the number of people or positions is attached to an air conditioner to allow comfortable driving according to indoor conditions, a night security system for buildings, etc. It is applied to the field.

A conventional pyroelectric infrared sensor will be described below with reference to FIGS. 5, 6 and 7.

As shown in FIG. 5, the infrared rays 4 emitted from the subject 7 pass through the chopper device 3 which intermittently cuts off to become intermittent infrared rays 5. The material of the sensor unit 2 is a pyroelectric element that generates a voltage when the temperature changes in proportion to the amount of infrared rays when it receives infrared rays. The pyroelectric type is used in accordance with the amount of infrared rays in each section of the intermittent infrared rays 5. The infrared sensor unit 2 generates an electromotive force.

FIG. 6 shows an arrangement state of the sensor section 2. For simplification of description, the sensor unit 2 is arranged vertically in a one-dimensional array.
It is assumed that each infrared sensor is used.

The chopper device 3 capable of passing only the infrared ray component perpendicular to the sensor part 2 and the chopper surface is horizontally rotated by the rotating device 6 and intermittently performed m times by one scanning, and as shown in FIG. The two-dimensional plane shown is observed as the surface distribution of the electromotive force according to the surface temperature of the object at each position of (m × n) pixels.

In the above structure, by performing mathematical processing on the observed planar distribution of electromotive force, a person or object in the space can be discriminated.

[0008]

In such a conventional infrared sensor, when n sensor portions 2 arranged in a one-dimensional array as shown in FIG. 5 and a chopper device 3 are horizontally rotated by a rotating device 6. , To observe the same observation point in terms of height without changing the vertical angle of the sensor, by performing m times intermittently in one scan, a two-dimensional plane distribution (m ×
There is a problem that the resolution is limited because it can be observed only as n) pixels.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a pyroelectric infrared sensor device of high resolution by changing the height of the sensor section.

[0010]

In order to achieve the above-mentioned object, the present invention has a plurality of sensor units arranged in a plane substantially perpendicular to the incident direction of infrared rays and detecting the infrared rays which have passed through the chopper device. , Having a rotation means for rotating the sensor unit about a rotation axis substantially perpendicular to the incident direction of infrared rays,
Inclination means for inclining the surface on which the sensor portion is arranged are provided.

[0011]

According to the present invention, the height of the sensor unit can be changed by tilting the portion holding the sensor unit by the tilting device when the sensor unit is rotationally scanned.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 is a side view showing a main body of a pyroelectric infrared sensor according to this embodiment. In FIG. 1, reference numeral 1 denotes an inclining device using a piezoelectric body 3 whose volume changes when the applied voltage is changed, but an electromagnet may be used instead of the piezoelectric body to incline the sensor unit 2, or a motor may be used. You may use. 2 is a sensor unit using a pyroelectric element that generates a voltage in proportion to the amount of infrared rays when it receives infrared rays, 3 is a chopper device that intermittently blocks the infrared rays 4 emitted from the subject 7,
An infrared ray 4 is emitted from the subject 7. By detecting the infrared ray 4, the position and the surface temperature of the subject are detected. Reference numeral 5 is an intermittent infrared ray, which is obtained by passing a continuous infrared ray 4 through the chopper device 3. When the continuous infrared ray 4 is divided into m pieces of infrared rays by this intermittent operation, the infrared rays are incident on the sensor unit 2 m times, so that the measurement can be performed m times. Reference numeral 6 is a rotating device that horizontally rotates the sensor unit 2 and the chopper device 3, and 7 is a subject to be measured.

Regarding the infrared sensor device having the above structure,
The operation will be described. As shown in FIG. 1, a continuous infrared ray 4 is emitted from the subject 7 and passes through the chopper device 3 to become an intermittent infrared ray 5. When the intermittent infrared rays 5 enter the sensor unit 2, the sensor unit 2 can detect the presence of the subject 7 by sensing the infrared rays. In this way, the number, position, etc. of people (subjects) can be measured. Moreover, since the rotating unit 6 rotates horizontally in the horizontal direction during measurement,
Similarly, the sensor unit 2 and the chopper device 3 are also horizontally rotated and can measure infrared rays over a wide range.

In the present invention, in particular, the sensor unit 2 not only horizontally and horizontally rotates but also moves vertically due to the action of the tilting device 1, so that a wider range of measurement can be performed.

The operation of the tilting device 1 will be described with reference to FIGS. 2 and 3. 2 and 3 show the sensor unit 2
3 is a partially enlarged view of the tilting device 1. FIG. Here, FIG. 2 shows the states of the tilting device 1 and the sensor unit when the rotating device 6 is rotating to the left, for example. Also,
FIG. 3 shows a state of the tilting device 1 and the sensor unit when rotating rightward, for example.

When the sensor unit 2 consisting of n pyroelectric elements arranged vertically one-dimensionally and the chopper device 3 are horizontally rotated by the rotating device 6 in the left and right directions, in the case of left scanning (FIG. 2).
And the case of right scanning (FIG. 3), the vertical angle of the sensor unit 2 is different. If the tilting device 1 scans while changing the tilt angle,
As shown in FIG. 3, not only the loci of infrared rays incident on the sensor unit 2 in one rotation scan on the left and right sides but also A ′,
Since B'and C'also pass, it is possible to measure up to a range that could not be measured conventionally.

FIG. 4 shows a plane distribution of electromotive force obtained from the sensor unit 2 when the infrared sensor device of this embodiment is operated. As shown in FIG. 4, when the rotation device 6 is rotated counterclockwise, the infrared rays incident at the heights A, B, and C are 1 to
It is possible to measure in the range of m, and for the infrared rays incident at the heights of A ', B', and C'when rotating to the right, 1
It can be measured in the range of ~ m. Therefore, in the present invention, planar pixel interpolation can be performed as compared with the conventional case shown in FIG. The number of pixels obtained by this is doubled, and the plane distribution can be set to (2 × m × n) pixels, and the plane distribution of highly accurate temperature change can be observed.

In this embodiment, the tilting device is operated when the sensor portion is rotated to the right, but the present invention is not limited to this mode, and the tilting timing may be appropriately selected. .

Further, although the rotating device is rotated in the horizontal direction, it goes without saying that the present invention can be applied even when the rotation axis is oriented in the horizontal direction.

In this embodiment, the chopper device and the sensor part rotate together. However, at least the sensor part needs to rotate, and even if the chopper device is fixed,
For example, the configuration may be such that it is provided in a cylindrical shape around the sensor unit.

Further, in the present embodiment, the infrared sensor is described as an example of the pyroelectric type, but the infrared sensor is not limited to this, and another infrared sensor may be used.

[0023]

According to the present invention, it is possible to provide a pyroelectric infrared sensor device capable of observing a plane distribution of temperature change with a resolution twice or more than ever before.

[Brief description of drawings]

FIG. 1 is a side sectional view of a pyroelectric infrared sensor according to an embodiment of the present invention.

FIG. 2 is a side sectional view of a pyroelectric infrared sensor provided with a tilting device.

FIG. 3 is a side sectional view of a tilted pyroelectric infrared sensor.

FIG. 4 is a plane distribution diagram of electromotive force with which a pyroelectric infrared sensor according to an embodiment of the present invention can be obtained.

FIG. 5 is a side sectional view of a conventional pyroelectric infrared sensor device.

FIG. 6 is a side sectional view of a conventional pyroelectric infrared sensor.

FIG. 7 is a plane distribution diagram of electromotive force with which a conventional pyroelectric infrared sensor can be obtained.

[Explanation of symbols]

 1 Tilt device 2 Sensor part 3 Chopper device 4 Infrared 5 Intermittent infrared 6 Rotating device 7 Subject

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location G01V 8/12 8/20

Claims (2)

[Claims] 1. A chopper device for intermittently blocking infrared rays, a plurality of sensor units arranged in a plane substantially perpendicular to the direction of incidence of the infrared rays, for sensing the infrared rays that have passed through the chopper device, and the incidence of the infrared rays. A rotating means that rotates together with the sensor section with a rotation axis in a direction substantially perpendicular to the direction;
An infrared sensor device having an inclining means for inclining a surface on which the sensor section is arranged. 2. A chopper device for intermittently blocking infrared rays, a plurality of sensor units arranged so as to face the chopper device for sensing infrared rays passing through the chopper device, and a direction of incidence of the infrared rays. An infrared sensor device comprising: a rotation unit that rotates together with the sensor unit and the chopper device about a substantially vertical direction as a rotation axis; and an inclination unit that inclines a surface on which the sensor unit is arranged.