JPH034097B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to an infrared image display device.

Conventionally, so-called thermography devices have been known that optically scan and detect infrared rays emitted from an object to be examined, such as a human body, and display the temperature distribution on the surface of the object as an image on a cathode ray tube surface. There is.

First, a conventional thermography apparatus will be explained with reference to FIG.

In FIG. 1, infrared rays are transmitted from a subject 1 such as a human body by a scanning mirror 3 in a camera unit 2, for example,
After being scanned in two dimensions at a scanning speed of seconds/frame,
The light is focused by an optical system 4 such as a lens, passes through a tipper (impeller) 5, and enters an optical sensor 6. This optical sensor 6 uses, for example, an indium antimony (In Sb) photoelectric conversion element, which has a fast response speed and high sensitivity, and is cooled with liquid nitrogen. The detection signal from the optical sensor 6 is supplied to a linearity correction circuit (linearizer) 8 via a preamplifier 7, and the absolute temperature of the subject 1 is
The infrared radiation characteristic proportional to the power is corrected to a linear characteristic. Therefore, the voltage of the output analog signal from the correction circuit 8 is proportional to the temperature of the subject 1. This analog signal is supplied to an analog/digital converter (hereinafter referred to as an A/D converter) 9,
For example, a 6-bit (64 level) digital data output signal from the A/D converter 9 is stored in the frame memory 10.
is memorized. The digital data signal stored in the frame memory 10 is output one after another at the same rate as a normal television image, for example, 30 frames/second, and is subjected to signal processing for a desired display mode (details will be described later) by the display mode switching device 11. After receiving
The signal is converted into an analog signal by a digital/analog converter (hereinafter referred to as an A/D converter) 12 and supplied to a display device 13, where it is displayed as a still image on the surface of the cathode ray tube.

The above-mentioned display modes include black and white display, black and white inverted display, isothermal line display, pseudo color display, etc. The display mode switching device 11
A display mode is selected by switching one of the signal processing circuits 11a to 11n using a switch 11s.

In the case of black and white display, the brightness of the displayed image is controlled according to the level of the input analog signal of the display device 13, and a reference brightness bar (so-called (grayscale) is displayed on the right edge of the same cathode ray tube surface.

Further, in the case of black and white inverted display, processing is performed to obtain the one's complement of the digital data successively output from the frame memory 10, and the output polarity of the D/A converter 12 is inverted.

In the case of isothermal line display, a digital comparator outputs and displays only digital data signals corresponding to the same brightness level. In this case, the display temperature range is divided into five equal parts, and four fixed isothermal lines are displayed every 20%. It is also possible to select and display isotherms at arbitrary temperatures within the display range.

In the case of pseudo-color display, the display temperature range is divided into multiple stages (e.g. 8 stages) using a digital window comparator, a different color is assigned to each stage to display a multicolor image, and a reference color bar is used. Displayed on the right edge of the same cathode ray tube surface.

As described above, conventionally, dedicated signal processing circuits 11a to 11n were provided for each display mode, and the display for the temperature signal was fixed. Therefore, when displaying a color or brightness that corresponds to a certain temperature with emphasis, or changing the color or brightness of the entire display range, it is necessary to prepare as many signal processing circuits as are necessary for the change. Therefore, the display mode cannot be easily changed, and even if the display mode could be changed, the device would be complicated and expensive. Moreover, since such change requests are wide-ranging and lack versatility, manufacturers are forced to carry out cumbersome product management.

In view of the above, it is an object of the present invention to provide an infrared image display device that eliminates the conventional drawbacks and allows the display mode to be easily changed using a common signal processing circuit.

Hereinafter, one embodiment of the infrared image display device according to the present invention will be described with reference to FIGS. 2 to 4.

FIG. 2 shows an embodiment of an infrared image display device according to the present invention. In FIG. 2, the subject and the camera section are the same as those in FIG. 1, so their illustration is omitted, and the same reference numerals are given to the parts corresponding to those in FIG. 1 to omit repeated explanation.

In FIG. 2, 14R, 14G and 14B are conversion table memories for signal processing, respectively.
4B has RAM (random access) with the same configuration.
memory) is used. FIG. 3 shows the memory 14
For example, a case is illustrated in which 64 words of black-and-white inversion luminance data of 6 bits per word are written in R, 14G, and 14B. Each conversion table memory 14R, 1
The 4G and 14B output data are converted into R, G, and B analog signals by corresponding D/A converters 12R, 12G, and 12B, and are supplied to the display device 13.

15 is a mode data memory, and this memory 15 is, for example, a ROM (read only).
memory) is used, and conversion table data for various display modes as described above are written.

16 is a mode conversion switch, and each display mode data from the mode data memory 15 is transferred to each conversion table memory 14 via the changeover switch 16.
R, 14G and 14B in parallel.

The operation of this embodiment is as follows. The 6-bit digital data signal successively outputted from the frame memory 10 is stored in each conversion table memory 14R, 14.
It is supplied to addresses corresponding to G and 14B data.

In the case of the black and white inverted display mode, data is written in each conversion table memory 14R, 14G, 14B so that the larger the address, the smaller the binary number, as shown in FIG. The output data of the memories 14R, 14G, and 14B are inverted in magnitude with the output data of the frame memory 10, and the white color in the displayed image is inverted.

To switch from the above-mentioned black and white inverted display mode to, for example, isothermal line display mode, press the mode changeover switch 1.
6 to read the isothermal line display mode data from the mode data memory 15 and write it into each conversion table memory 14R, 14G, and 14B, and rewrite each memory 14R, 14G, and 14B.

For the isotherm display mode data, as illustrated in FIG. 4, data "1" is written only in the address corresponding to the desired display temperature, and data values of all remaining addresses are set to "0".

Further, for example, in the case of pseudo-color display, separate conversion table data may be prepared in each conversion table memory 14R, 14G, and 14B.

As described in detail above, according to the present invention, each conversion table memory 14R for signal processing,
Since 14G and 14B are rewritten, it is possible to easily handle various display modes with a general-purpose and simple configuration.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a configuration example of a conventional infrared image display device, FIG. 2 is a block diagram showing an embodiment of an infrared image display device according to the present invention, and FIGS. 3 and 4 are explanations of the present invention. 2 is a schematic diagram showing a data format used for 1 is a subject, 2 is a camera unit, 10 is a frame memory, 11 is a display mode switching device, 13 is a display device, 14R, 14G and 14B are conversion table memories, 15 is a mode data memory, and 16 is a mode switching switch. .

Claims (1)

[Claims] 1. In an infrared image display device having an imaging means for two-dimensionally scanning and detecting infrared radiation from a subject to obtain a video signal, and an image display means for displaying the video signal from the imaging means in a plurality of display modes, the above-mentioned The image display means includes display mode storage means for storing a plurality of display mode data corresponding to the plurality of display modes, and a conversion table storage means,
An infrared image display device according to claim 1, wherein the conversion table storage means is selectively supplied with the plurality of display mode data from the display mode storage means so that the stored contents can be rewritten.