JP2605448B2 - Defect and sensitivity correction device for two-dimensional array type infrared video camera - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to compensation for defective pixels of a two-dimensional array type infrared video camera and correction for uniforming sensitivity within a screen.

[Conventional technology]

FIG. 3 shows an example of a method of compensating for defective pixels of a conventional two-dimensional array type infrared video camera and a method of correcting sensitivity for obtaining a uniform screen output with respect to a uniform incidence on a detector.

(1) is a two-dimensional array type infrared detector, (2) is a first ROM, (3) is a second ROM, (4) is an A / D converter,
(6) is a defect correction circuit, (8) is a sensitivity correction circuit, (11)
Is the analog output signal from the infrared detector, (12) is the digital output signal converted by the A / D converter, (1)
3) Digital output signal corrected for defective pixels, (14)
Is the latest digital output signal for which sensitivity correction has been completed.

An infrared detector (1), an A / D converter (4) for converting an analog signal (11) output from the detector (1) into digital data (12), and address data of a defective pixel are stored. A first ROM (2) and a second ROM (3) storing sensitivity correction data for compensating for sensitivity non-uniformity
And a defect correction circuit (for example, a flip-flop using a flip-flop as shown in FIG. 4) for the defective pixel to make up for the defective pixel with the same data as the previous normal pixel. 6) and, for example, a sensitivity correction circuit for each pixel by a multiplication circuit, and finally a digital signal subjected to defect correction and sensitivity correction is obtained.

[Problems to be solved by the invention]

In such a camera, since the camera head and the camera controller having the defect and sensitivity correction data are separated, the camera head and the camera controller must always correspond one-to-one. Another problem is that the camera controller is not compatible.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and even if a camera head or a camera controller needs to be replaced for some reason, there is no need to replace the camera head or the camera controller with a compatible device so as not to hinder the defect and sensitivity correction. The purpose is to do.

[Means for solving the problem]

A first ROM storing defective pixel address data;
A second ROM storing sensitivity correction data is mounted on the camera head, and a transmitter and a receiver are mounted on the camera head so that the contents of these memories can be transferred from the camera head to the camera controller. And a first RAM for storing the contents of the first ROM so that the camera controller can perform correction processing.
And a second RAM for storing the contents of the second ROM are mounted on the camera controller.

Thus, even if the camera head is replaced with another camera head, or the camera controller is replaced with another camera head, an appropriate correction is made.

Further, by setting certain data of the sensitivity correction data as data indicating a defective pixel and mounting a decoder for identifying the certain data indicating the above-described defective pixel in the camera controller, And the first RAM is reduced.

[Action]

According to the present invention, since the correction data for each camera head is mounted on the ROM of the camera head and the contents of these ROMs can be transferred to the RAM on the camera control side, compatibility of the camera head or the camera controller is made possible.

〔Example〕

FIG. 1 shows the embodiment. A first RAM (5) for storing defective address data transferred from the first ROM (2) via the transmitter (9) and the receiver (10);
The second RA storing the sensitivity correction data transferred from the ROM (3) through the transmitter (9) and the receiver (10).
According to M (7), the camera head or camera controller can be compatible.

That is, the contents of the first ROM (2) are transferred to the first RAM (5), and the contents of the second ROM (3) are transferred to the second RAM (7). , The second ROM is mounted on the camera controller, and the first RAM
The defective pixel address data of (5) is sent to a defect correction circuit (6) for each pixel, where a defect compensation process is performed. The normal pixels are output from the defect correction circuit (6) without any processing. Further, the sensitivity correction data is output from the second RAM (7) for each pixel, and becomes a digital output signal (14) corrected in sensitivity by the sensitivity correction circuit (8).

By the way, defective pixel address data is 1-bit data for identifying whether each pixel is defective or normal. On the other hand, data corresponding to a defective pixel in the sensitivity correction data is data for sensitivity correction. Is unnecessary data, so that data corresponding to a defective pixel in the sensitivity correction data is given a predetermined identification code to indicate that the pixel is a defective pixel, and the memory is used as one memory. Things are also possible. For example, when the sensitivity correction gradation is 256 gradations, data of one gradation out of these, for example, all bits are 1
Alternatively, if data in which all bits are 0 is set as the identification code of the defective pixel, the sensitivity correction gradation is reduced to 255 gradations, but there is an advantage that one memory can be reduced.

FIG. 2 shows this embodiment. The sensitivity data from the RAM (5) in which the code indicating the defective pixel and the sensitivity correction data are recorded, and the output digital signal (1) from the A / D converter
2) is corrected by the sensitivity correction circuit (8), and the data from the RAM is identified by the decoder (15) as to whether the data is a data code indicating a defective pixel or sensitivity correction data for a normal pixel. . The output signal of the decoder (15) is sent to the defect correction circuit (6) which is determined to be data indicating a defective pixel, and the sensitivity corrected signal (13) is latched by the latch circuit (6), for example. Pixels are output, and a digital signal (14) corrected for defects and sensitivity is output.

〔The invention's effect〕

As described above, according to the present invention, even if the camera head is different or the camera controller is different, the defective pixel data and the sensitivity correction data corresponding to the detector are stored in the ROM.
Recorded on the camera head and transferred to the RAM mounted on the camera controller, so that the correction is executed by the camera controller and the compatibility between the devices can be maintained. .

[Brief description of the drawings]

1 and 2 are diagrams showing an embodiment of the present invention, FIG. 3 is a diagram showing a configuration of a conventional defect and sensitivity correction device, and FIG. 4 is a diagram showing a latch circuit for defective pixel compensation. (1) is an infrared detector, (2) is a first ROM, (3) is a second ROM,
(4) is an A / D converter, (5) is a first RAM, (6) is a defect correction circuit, (7) is a second RAM, (8) is a sensitivity correction circuit, (9) is a transmitter, (10) is a receiver, (11) is an uncorrected infrared video signal, (12) is a digital video signal,
(13) is a digital video signal with defect compensation, (14) is a digital video signal with defect and sensitivity corrected, (15) is a decoder, (16) is a digital video signal, (17) is a clock signal, and (18) is ROM data. , (19) are latch enable terminals. In the drawings, the same or corresponding parts are denoted by the same reference numerals.

Claims (2)

(57) [Claims] 1. A defect and sensitivity correction apparatus for a two-dimensional array type infrared video camera in which a camera head and a camera controller are separated from each other, wherein a first defective pixel address of an infrared detector provided in the camera head is stored.
A ROM, a second ROM storing sensitivity correction data for each pixel of the infrared detector placed in the camera head, and a camera controller provided in the camera head and storing data in the first and second ROMs. And a circuit provided in the camera controller and receiving the transmission data, and a first circuit provided in the camera control and storing the contents of the first ROM and the second ROM, respectively. A second RAM, an A / D converter for converting an analog voltage of the infrared detector into a digital signal, and a defect correction circuit for correcting a defect of the infrared detector using data from the first RAM. And a sensitivity correction circuit for correcting a variation in sensitivity of each pixel of the infrared detector using data from the second RAM. And sensitivity correction device. 2. A defect and sensitivity correction device for a two-dimensional array type infrared video camera in which a camera head and a camera controller are separated from each other, wherein a RO storing defect pixel address data and sensitivity correction data to be mounted on the camera head is stored.
M, a circuit provided in the camera head for transmitting data of the ROM to the camera controller, a circuit provided in the camera controller, for receiving the ROM data transmitted from the transmission circuit, and a camera controller RAM that stores received ROM data
A decoder for identifying certain data from the RAM; an A / D converter for converting an analog output voltage of the infrared detector into a digital signal; and a pixel of the infrared detector using data from the RAM. A sensitivity correction circuit for correcting a variation in sensitivity for each, a decoder connected to the RAM, and a defect correction circuit for correcting a defect of the infrared detector by using an output of the decoder. Defect and sensitivity correction device for two-dimensional array type infrared video camera.