JPH05346346A - Pyroelectric type infrared ray sensor - Google Patents

Abstract

PURPOSE:To obtain a pyroelectric type infrared ray sensor with a wide range of detection area without using an auxiliary object such as a lens or a plurality of pyroelectric type infrared ray sensor units. CONSTITUTION:In the title sensor with a plurality of infrared ray detection parts, a light reception surface 3 of each infrared ray detection part is not provided on the same plane and is directed toward an arbitrary direction. The sensitivity directional characteristics of the title sensor can be widened without using an auxiliary object such as a lens or a plurality of pyroelectric type infrared ray sensor units.

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.

[0002]

2. Description of the Related Art An example of the structure of a conventional pyroelectric infrared sensor is shown in FIG. It is composed of a pyroelectric substrate (2) formed in a thin plate and opposing electrodes (1) provided on the front and back sides thereof. Here, in recent years, one infrared sensor having a wide detection area is required.
However, in the conventional structure, the light-receiving surface (3) of the infrared detector (hereinafter referred to as an element) is a single plane,
The sensitivity directivity of the sensor is as shown in FIG. 3-b), and it was difficult to widen the directivity. Therefore, using optical systems such as lenses and mirrors,
There is a problem that it is necessary to use a plurality of infrared sensor units.

[0003]

As described above, a pyroelectric infrared sensor having a wide detection area without using an optical system such as a lens and a mirror or using a plurality of infrared sensor units is provided. The provision is the problem to be solved by the present invention.

[0004]

The present invention has been made to solve the above problems. The means to do so is to form the light receiving surface with a curved surface or to form an element with a plurality of surfaces facing a plurality of directions on the same substrate.

[0005]

In the present invention configured as described above,
The detection area is as if the detection areas according to the conventional method are overlapped in the normal direction of the curved surface or the normal direction of a plurality of surfaces. Therefore, the detection area as a whole is obviously wider than that of the conventional method.

[0006]

Embodiments of the pyroelectric infrared sensor according to the present invention will be described below in detail with reference to the drawings. 1 is a sectional view of a pyroelectric infrared sensor showing an embodiment of the present invention, and FIG.
It is a figure which shows the manufacturing method of -a). First, by mechanical cutting such as dicing, as shown in FIG.
O ₃ -PbZrO ₃₎ processing the pyroelectric substrate (2) made of a pyroelectric material system. Next, an electrode material is formed on the surface by plating, and the electrode material on the light receiving surface (3) is mechanically polished to form the electrode (1) as shown in FIG. Then, it is formed again by mechanical cutting as shown in FIG. As described above, the pyroelectric infrared sensor according to the present invention is formed. Here, as the material of the pyroelectric substrate (2), a (PbTiO ₃ —PbZrO ₃ ) based material is used, but other materials such as PbTiO ₃ based, NbTaO ₃ based, L
Any pyroelectric material such as iTaO ₃ series or TGS series may be used, and the crystal state may be either a single crystal body or a polycrystal body,
Further, it may be a complex with a polymer. Although the dicing method is used for each processing here, other methods such as etching, laser processing, and ion milling may be used.
The same effect can be obtained. Although the electrode (1) is formed by plating here, it may be formed by a vapor phase thin film forming method such as vapor deposition. Here, mechanical polishing is used to remove the electrode material on the light-receiving surface (3), but other methods such as etching may be used, and a lift-off method, a vapor phase thin film forming method using a mask, etc. may be used. It may not be formed from the beginning. In this case, the structure described in Japanese Patent Application No. 3-103135 filed by the present applicant is used as the basic structure of the element.
As shown in (b), a recess may be provided on the back surface of the pyroelectric substrate (2), and electrodes (1) may be provided on the inner surface and the light receiving surface of the pyroelectric substrate (2) to provide a structure as in the conventional method. Here, each light receiving surface (3) is a flat surface, but may be a curved surface. Fig. 1-b)
The light receiving surface may be a single curved surface as shown in FIG.
The wiring method of each element is serial connection here, but it may be parallel connection, or wiring on the substrate,
It may be wired externally, and various applications can be dealt with depending on the wiring method of the element.

FIG. 4 shows the sensitivity directivity characteristic of the pyroelectric infrared sensor according to the present invention. The directional characteristics shown by the dotted line are the directional characteristics like the solid line obtained by superimposing the directional characteristics by the conventional method, and it can be confirmed that the directional characteristics are clearly wider than the conventional one.

[0008]

As described above, according to the present invention, the sensitivity directivity characteristic of the pyroelectric infrared sensor can be widened without using an auxiliary one such as a lens or using a plurality of infrared sensors. It is of industrial value in that it enables In addition, it can be applied to diversifying thermal infrared sensors and has great industrial value.

[0009]

[Brief description of drawings]

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

FIG. 2 is a diagram showing a manufacturing method of an embodiment of the pyroelectric infrared sensor according to the present invention.

FIG. 3 is a cross-sectional view showing a structure of a pyroelectric infrared sensor according to a conventional method and a diagram showing sensitivity directivity characteristics.

FIG. 4 is a diagram showing a sensitivity directivity characteristic of an embodiment of a pyroelectric infrared sensor according to the present invention.

[Explanation of symbols] 1 electrode 2 pyroelectric substrate 3 light receiving surface

Claims (2)

[Claims] 1. A pyroelectric infrared sensor, characterized in that, in the pyroelectric infrared sensor, the light receiving surface of the infrared detecting section is composed of a plurality of surfaces facing a plurality of directions. 2. The pyroelectric infrared sensor according to claim 1, wherein the light receiving surface of the infrared detector is a curved surface.