JPS6017715Y2 - infrared detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in an optical system that makes it possible to condense light rays near the rotation axis of a rotary chopper, which has conventionally been impossible to detect.

Infrared detectors use imaging optical systems, such as biconvex lenses, so if the detector, especially a linear array type multi-component detector, is placed near the center of the chopper in the radiation pattern, the chopper will be distorted near the rotation axis. The interval between the transparent and opaque regions of the film becomes very narrow, and is equal to or smaller than the width of one film, so that a sufficient chopping effect cannot be expected.

Therefore, in the past, the detector was installed at a position slightly offset from the rotation axis so that the light source could be detected.

In this case, there is a drawback that the detection of the light source near the rotation axis is inefficient, resulting in poor field of view utilization efficiency.

In order to eliminate the above-mentioned drawbacks, the present invention adds a new prism to the optical system, and by providing this prism, it is possible to detect light rays near the rotation axis, which was previously impossible to detect. This paper proposes an infrared detection device.

The infrared detection device according to the present invention will be described in detail below with reference to the drawings.

1A and 1B are a plan view and a side view, respectively, of a radial pattern chopper, where 1 is the chopper, 2 is an infrared detector, and 3 is a rotating shaft.

As you can see in the figure, the distance between transparent and opaque is very narrow near the center of chopper 1, so if the detector is installed near the center of chopper 1 like 2', chopper Therefore, the detector 2 is usually installed in the position shown in the figure.

FIG. 2 is a side view showing the arrangement of a chopper, a condensing system, such as a lens, and a multi-element array type infrared detector, and the same reference numerals are used for the same parts as in the previous figure.

4 is a condensing system, for example, a biconvex lens is used; 5, 6.
7 is an incident ray.

As can be seen, the light rays 5, 6 pass through the condensing system 4 and the chopper 1 and are detected by the detector 2, while the light rays 7, for example, near the axis of rotation 3 of the chopper are not utilized.

Therefore, in such an arrangement, light rays passing near the rotation axis cannot be detected, resulting in a so-called blind spot.

FIG. 3 is a side view showing an example of an improved arrangement of the optical system according to the present invention, and the same reference numerals are used for the same parts as in the previous figure.

Reference numeral 8 denotes a prism, and by newly providing this prism 8, it is possible to utilize light rays near the chopper rotation axis, which were hitherto impossible to utilize because they did not enter the detection element.

As can be seen in the figure, the light beam 7 is refracted by a prism 8 and passes through a condensing system such as a convex lens 4 and a chopper 1 to a detector 2.
Since it can be detected by the optical axis, it is also possible to scan only the area close to the optical axis.

As described above, the infrared detection device according to the present invention is equipped with a prism in the optical system, and it is possible to effectively use the light rays near the chopper rotation axis, which was considered impossible to detect with conventional methods, and to detect high-performance infrared rays. A detection device can be provided.

In addition, condensing systems are not limited to lenses; concave mirrors and optical fiber cones may also be used, and prisms are of course angled according to the purpose of use, and are not limited to one prism but can be configured to combine multiple prisms. is also possible.

[Brief explanation of the drawing]

Figures 1A and B are respectively a top view of the radial pattern chopper and a side view showing the location of the infrared detector;
The figure is a side view showing the arrangement of a conventional chopper, condensing system, and infrared detector, and FIG. 3 is a side view showing an embodiment of the infrared detection device according to the present invention. 1: Chopper, 2.2': Infrared detector, 3: Chopper rotation axis, 4: Condensing system, 5, 6, 7: Incident light, 8 Nibrism.

Claims (1)

[Scope of utility model registration request] In an infrared detection device, the rotational axis of a chopper having a radial pattern is aligned on the incident optical axis of a condensing system, and an infrared detector is arranged behind the chopper. An infrared detection device, characterized in that light on an incident optical axis is bent and made to enter the infrared detector, which is arranged so as to face a chopper surface away from a rotation axis of a chopper.