JPH07181084A - Infrared image processor - Google Patents

Abstract

PURPOSE:To provide an infrared image processor applicable to the measurement of temperature distribution for the dark view unit of aircraft, the guide unit for flying object, etc., in which the noise due to Narcissus radiation 1 is removed. CONSTITUTION:An infrared ray R enters through a lens 1 into an infrared detector 2 where it is subjected to photoelectric conversion to produce an electric signal which is fed through an amplifier 3 to an A/D converter 4. The infrared detector 2 is cooled by a cooler 7 and Narcissus radiation N accompanied therewith is reflected on the lens 1 and mixed into the infrared ray R. The signal of Narcissus radiation N is prestored in a memory 5 and a subtractor 6 subtracts a data B stored in the memory from a mixed signal A of infrared ray and Narcissus radiation. Consequently, the signal caused by Narcissus radiation is removed and an original signal C of infrared ray can be outputted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an infrared image processing apparatus used for temperature distribution measurement of night vision devices for aircraft, guidance devices for flying objects, and the like.

[0002]

2. Description of the Related Art In a conventional infrared image processing apparatus, as shown in the configuration diagram of FIG. 2, an infrared detector 2 detects an infrared ray R incident through a lens 1, photoelectrically converts the infrared ray R, and an amplifier 3 widens the width. Converted to a digital signal via the / D converter 4 and VT
It outputs to R etc. as an output signal C. Here, the infrared detector 2 is cooled to about 100 degrees K by the cooler 7.

[0003]

In the conventional infrared image processing apparatus of this type, as described above, the infrared ray R from the outside is used.
The infrared detector 2 performs photoelectric conversion to obtain an output signal. However, since the infrared detector 2 is cooled to about 100 degrees K by the cooler 7 in order to suppress its own thermal noise, The so-called narcissus radiation N, which emits radiation, is reflected by the lens 1 and is incident on the infrared detector 2 again.
And photoelectric conversion will be performed. Therefore, the original infrared ray R may not be detected correctly.

Since the lens 1 is generally convex, the narcissus radiation N is strong in the vicinity of the center of the optical axis, and as a result, in the infrared image processing apparatus, the target is dark near the center of the image and is photographed nonuniformly.

[0005]

In order to solve such a problem, the present invention adds a circuit for removing the influence of the amount of narcissus radiation generated by cooling the infrared detector to the conventional infrared image processing apparatus. The target infrared image signal is accurately obtained.

[0006] That is, the present invention is a lens that receives infrared rays, an infrared detector that receives the infrared rays that enter from the lens, photoelectrically converts the infrared rays and outputs an electric signal, and a cooler that cools the infrared detectors. An infrared image processing apparatus comprising: an A / D converter that outputs the output of the infrared detector via an amplifier to obtain a digital signal, and outputs the signal from the A / D converter to an external device as an output signal, A memory in which a signal of a narcissus radiation amount caused by cooling of the infrared detector by the cooler is stored in advance;
A circuit for removing the signal stored in the memory from the output signal from the converter, and outputting the signal from the circuit to the external device as an output signal. To do.

[0007]

According to the present invention, the infrared ray enters the infrared ray detector through the lens, is photoelectrically converted into an electric signal, and enters the A / D converter through the amplifier. On the other hand, the infrared detector is cooled by the cooler, and accordingly, narcissus radiation is generated, reflected by the surface of the lens and incident on the infrared detector, and this signal is mixed with the infrared signal. This mixed narcissus radiation signal is stored in a memory in advance, and the circuit for removing the signal stored in this memory from the infrared signal mixed with narcissus radiation subtracts the narcissus radiation signal and outputs it to an external device. Therefore, it is possible to eliminate the problem that the vicinity of the center of the infrared image becomes dark, which has been a problem in the past.

[0008]

Embodiments of the present invention will be specifically described below with reference to the drawings. FIG. 1 is a configuration diagram of an infrared image processing apparatus according to an embodiment of the present invention. In the figure, reference numerals 1 to 4
Since 7, R and N are the same as the conventional ones, they will be described by quoting them as they are.
This is part 6 and will be described in detail below.

In the figure, an infrared ray R passes through a lens 1 and enters an infrared ray detector 2, where it is photoelectrically converted and an amplifier 3
Is amplified by. The amplified signal is converted into a digital signal by the A / D converter 4 and enters the subtractor 6.

On the other hand, the infrared detector 2 has a cooler 7 of 100
Since it is cooled to about K degree, Narcissus radiation N is generated by low temperature radiation, reflected on the surface of the lens 1 and reflected by the surface of the lens 1 through the infrared detector 2, the amplifier 3 and the A / D converter 4. It becomes a digital signal and becomes a signal combined with the infrared ray R.

Narcissus radiation means low-temperature radiation generated by an infrared detector cooled to about 100 degrees K due to this cooling, and as described above, this is reflected by the lens in front, When it enters the infrared detector again, there is a problem that due to the effect of this mixed signal, the vicinity of the center of the infrared image serving as an output signal becomes dark.

The memory 5 stores digital data corresponding to narcissus radiation, and the infrared image processing apparatus stores the narcissus data in advance. As for the storage method, a uniform temperature target is photographed in advance, and the distribution of the digital signal of only the narcissus radiation signal at that time is stored.

The subtractor 6 receives a signal A, which is the sum of the input infrared R signal and the narcissus radiation amount signal, but subtracts the signal B from the memory 5 containing only the narcissus component, and subtracts the output C from the VTR, Output to etc.

For this reason, since the output signal C does not include the influence of narcissus radiation, the target infrared image can be captured on the VTR or the like, and the infrared image processing device with high accuracy can be obtained.

[0015]

As described above in detail, in the present invention, the conventional infrared image processing apparatus is provided with a memory in which the signal of the narcissus radiation amount is previously stored, and the detected infrared signal Since a circuit for removing the signal stored in the memory is provided, it becomes possible to accurately capture the target infrared image by the compensation effect of the narcissus data, and the central part of the infrared image, which has been an obstacle in the past, becomes dark. This phenomenon is improved and an accurate infrared image processing device is realized.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an infrared image processing apparatus according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of a conventional infrared image processing device.

[Explanation of symbols]

 1 Lens 2 Infrared Detector 3 Amplifier 4 A / D Converter 5 Memory 6 Subtractor C Output Signal R Infrared N Narcissus Radiation

Claims (1)

[Claims] 1. A lens which receives infrared rays, an infrared detector which receives the infrared rays incident from the lens and photoelectrically converts the infrared rays to output an electric signal, a cooler which cools the infrared detector, and the infrared detector. An infrared image processing apparatus for outputting the signal from the A / D converter as an output signal to an external device. And a circuit for removing a signal stored in the memory from an output signal from the A / D converter, the memory storing in advance a signal of a narcissus radiation amount caused by cooling by the cooler. The infrared image processing apparatus, wherein the signal from the circuit is output as an output signal to the external device.