JPH04881A - Fault and sensitivity correction device for two-dimensional array type infrared video camera - Google Patents

Abstract

PURPOSE:To make a camera head or camera controller of the above camera interchangeable by mounting correction data of each camera head into the camera head ROM of each camera head and transferring the content of the ROMs to a RAM on the camera controller side. CONSTITUTION:Because of the first RAM 5 for storing fault address data trans ferred from the first ROM 2 via a transmitter 9 and receiver 10 and second RAM 7 for storing sensitivity correcting data transferred from the second ROM 3 via the transmitter 9 end receiver 10, the camera head or camera controller of a two. dimensional array type infrared video camera can have interchangeabil ity. By transferring the content of the first ROM 2 to the first RAM 5 and the content of the second ROM 3 to the second RAM 7, the address data of faulty picture elements in the first RAM 5 are sent to a latch circuit 6 at every picture element and fault compensating processes are performed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to compensation for defective pixels in a two-dimensional array type infrared video camera and correction for equalizing sensitivity within the screen.

[Conventional technology]

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

(1) is a two-dimensional array type infrared detector, (2) is the first
ROM, (3) is second ROM, (4) is A/D
converter, (6) is a defect correction circuit, (8) is a sensitivity correction circuit, (11) is an analog output signal from an infrared detector, (12) is a digital output signal converted by an A/D converter, (13) ) is the digital output signal after defective pixel correction, and (14) is the final digital output signal after sensitivity correction has been completed.

An infrared detector (1), an A/D converter (4) that converts the analog signal (11) output from the detector (1) into digital data (12), and address data of the defective pixel is stored. and a first ROM (2).

The second one stores sensitivity correction data that compensates for sensitivity non-uniformity.
ROM (3) and 1 For example, a latch circuit using a flip-flop as shown in Figure 4 is used to compensate for a defective pixel with the same data as the previous normal pixel. It consists of a defect correction circuit (6) and a sensitivity correction circuit for each pixel (9), for example, one multiplication circuit, and finally obtains a digital signal that has been subjected to defect correction and sensitivity correction.

[Problem to be solved by the invention]

In the above-mentioned cameras, the camera head and the camera controller equipped with defect and sensitivity correction data are separated, so the camera head and camera controller must always correspond on a one-to-one basis, even if they are of the same model. However, the problem was that the camera heads or camera controllers were not compatible.

The present invention was made to solve these difficulties, and even if the camera head or camera controller needs to be replaced for some reason, it is compatible so that defects and sensitivity correction will not be affected. It is intended to be used as a device.

[Means to solve 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 is mounted on the camera head and a receiver is mounted on the camera controller so that the contents of these memories can be transferred from the camera head to the camera controller. A circuit for defect correction and a circuit for sensitivity correction are installed in the camera controller, and the first ROM stores the contents of the first ROM so that the camera controller can perform correction processing.
and a second RAM that stores the contents of the second ROM are installed in the camera controller.

As a result, even if the camera head is replaced with another camera head or the camera controller is replaced with another camera controller, appropriate corrections will be made.

Furthermore, by using certain data of the sensitivity correction data as data indicating a defective pixel, and installing a decoder for identifying the certain specific data indicating the defective pixel in the camera controller, the first ROM and the first RAM
It was designed to reduce the

[Function] In the present invention, different correction data for each camera head is loaded into the ROM of the camera head, and the contents of these ROMs can be transferred to the RAM on the camera control side, thereby improving the compatibility of the camera head or camera controller. made possible.

〔Example〕

An example is shown in FIG. A first RAM (5) that stores defective address data transferred from the first ROM (2) via the transmitter (9) and receiver (10), and a second ROM (3). From, the transmitter (9).

A second RAM (7) in which the sensitivity correction data transferred via the receiver (10) is stored allows the camera head or camera controller to be compatible.

That is, the first RAM (5) is connected to the first ROM (2).
), the contents of the second RAM (7) are stored in the second ROM (
By transferring the contents of 3), it becomes as if the first and second ROMs are installed in the camera controller, and the defective pixel address data in the first RAM (5) is stored in the latch for each pixel. It is sent to the circuit (6), where it undergoes defect compensation processing. Normal pixels are output from the latch circuit (6) without undergoing any processing. Furthermore, a second RA
Sensitivity correction data is output from M (7) for each pixel, and multiplied by the signal (13) output from the latch circuit in a multiplier circuit (8) to produce a sensitivity-corrected digital output signal (14).
becomes.

By the way, the defective pixel address data is 1-bit data for identifying whether each pixel is defective or normal.On the other hand, the data corresponding to the defective pixel in the sensitivity correction data is used for sensitivity correction. is unnecessary data, so the data corresponding to the defective pixel in this sensitivity correction data is given a predetermined identification code to indicate that it is a defective pixel, and the memory is made into one memory. It is also possible. For example, when the sensitivity correction gradation is 256 gradations, data for one gradation, for example, data in which all bits are 1 or all pips are 0, can be set as the defective pixel identification code. , the number of sensitivity correction gradations is reduced to 255 gradations, but the advantage is that the number of memories can be reduced by one.

FIG. 2 shows this embodiment. The pressure sensitive 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 (12) from the A/D converter are multiplied by the multiplier circuit (8).

The data from the RAM is identified by a decoder (15) as to whether the data is a data code indicating a defective pixel or sensitivity correction data for a normal pixel. When it is determined that the data indicates a defective pixel, a latch enable signal is sent to the enable terminal of the latch circuit (6), and the latch circuit (6) outputs 1, for example, the data of the pixel in response to the sensitivity corrected signal (13). is replaced with the previous pixel data, and a defect and sensitivity corrected digital signal (14) is output.

〔Effect of the invention〕

As explained above, even if the camera head or camera controller is different, the defective pixel data and sensitivity correction data corresponding to the detector are stored in the ROM.
This data is stored in the camera head and transferred to the RAM in the camera controller, so corrections are executed in the camera controller, making it possible to maintain compatibility between devices. be.

[Brief explanation of the drawing]

FIGS. 1 and 2 are diagrams showing embodiments of the present invention. FIG. 3 is a diagram showing the configuration of a conventional defect and sensitivity correction device;
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, and (6) is a latch circuit. (7) is the second RAM, (8) is the multiplication circuit, (9) is the transmitter, (10) is the receiver, (11) is the uncorrected infrared video signal, (12) is the digital video signal,
(13) is a defect-compensated digital video signal, (14)
is a defect/sensitivity corrected digital video signal, (15
) is a decoder. (16) is a digital video signal, (17) is a clock signal, (18) is ROM data, and (19) is a latch enable terminal. Note that the same or corresponding parts in FIG. 9 are given the same reference numerals.

Claims (2)

[Claims] (1) In a defect and sensitivity correction device for a secondary array type infrared video camera consisting of a camera head and a camera controller, a first ROM that stores a defective pixel address of an infrared detector placed in the camera head, and a camera a second ROM that stores sensitivity correction data for each pixel of an infrared detector placed in the head; and a second ROM placed in the camera head that transmits data in the first and second ROMs to the camera controller. a circuit, a circuit placed in the camera controller and receiving the transmission data, a first RAM storing the contents of the first ROM, and a second RAM.
A second RAM that stores the contents of the ROM, an A/D converter that converts the analog voltage of the infrared detector into a digital signal, and data from the first RAM are connected to an enable terminal, and the A/D The present invention includes a latch circuit to which the digital signal from the converter is connected to an input terminal, and a multiplier circuit connected to multiply the data from the second RAM and the output data from the latch circuit. Features: Defect and sensitivity correction device for two-dimensional array type infrared video camera. (2) In a defect and sensitivity correction device for a two-dimensional array infrared video camera consisting of a camera head and a camera controller, a ROM that stores defective pixel address data and sensitivity correction data to be mounted on the camera head, and a ROM inside the camera head. a circuit placed in the camera controller for transmitting the ROM data to the camera controller; a circuit placed in the camera controller for receiving the ROM data transmitted from the transmission circuit; a RAM for storing the received ROM data; A decoder that identifies certain data from the RAM, an A/D converter that converts the analog output voltage of the infrared detector into a digital signal, and the data from the RAM and the digital signal from the A/D converter are multiplied. a multiplier connected to the RAM and a decoder connected to the RAM;
A defect and sensitivity correction device for a two-dimensional array type infrared video camera, comprising a latch circuit in which the output of the decoder is connected to an enable terminal, and the output of the multiplier is connected to a data input terminal.