JPS6151249B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a thermography apparatus that optically scans an object and displays an infrared image of the object on a cathode ray tube.

[Prior Art] In a thermography device, a subject is optically scanned, infrared rays emitted from various parts of the subject are detected by the scanning, and the obtained infrared image signal (temperature signal) is displayed on a display device such as a cathode ray tube. The infrared image of the subject is displayed on its screen. The brightness of the infrared image of the subject displayed on the display device needs to be adjusted to be suitable for visual observation or photographic observation.

[Problem to be solved by the invention] Conventionally, this brightness level adjustment was done by automatically determining the center level based on the average value of the temperature signal spread over the entire screen, so it is necessary to observe it in detail. If a portion deviated significantly from the average value, that portion could not be observed in good condition.

The present invention has been made to solve these drawbacks, and provides a thermography device that can automatically adjust the brightness so that the part you want to observe in detail is always displayed at the center brightness. It is.

[Means for Solving the Problems] Therefore, the present invention optically scans a subject to detect infrared rays emitted from each part of the subject, and detects the temperature based on the temperature signal obtained by detecting the infrared rays. In a thermography device configured to display a temperature distribution image of a subject on a display device, means for displaying a mark superimposed on the subject image on the display device, and for arbitrarily moving the displayed position of the mark. means for automatically extracting and holding a signal corresponding to the display position of the mark from among the temperature signals; and means for obtaining a difference signal between the temperature signal and the extracted signal. By introducing the difference signal into the display device, the image is displayed with the part of the image corresponding to the mark as the center brightness.

[Operation] In the present invention, a mark is displayed superimposed on the temperature distribution image of the subject displayed on the screen of the display device, and a signal corresponding to the display position of the mark is extracted from the temperature signal, and this extracted signal is Since the difference signal between the mark display position and the temperature signal is supplied to the display device, the image is displayed with the center brightness at the part of the image corresponding to the mark display position. Therefore, by moving the mark to the part you want to observe, a temperature distribution image of the subject will be displayed with that part as the center brightness, allowing you to observe that part in detail.

Hereinafter, one embodiment of the present invention will be explained in detail using the drawings.

[Example] Fig. 1 is a block diagram showing an example of a thermography apparatus embodying the present invention, and S in the figure optically scans a subject 3 horizontally and vertically, and detects infrared rays emitted from various parts of the subject. This is an optical scanning mechanism that guides the infrared rays to the infrared detector D for detection. 1 is a scanning signal generation circuit, which generates a horizontal scanning signal SH.
and the vertical scanning signal SV is the optical scanning mechanism S.
It is also supplied to the negative terminals of comparators 2H and 2V. The positive terminals of the comparators 2H and 2V are connected to mark position adjustment signal generators 5H and 5V for adjusting the position of the mark 4 displayed as a bright spot (or dark spot) on the screen of the display device, as shown in FIG. Mark position signal MH from
MV is supplied as a reference signal. 6 is a timing circuit, which receives the signal of the negative terminal of the comparator 2V.
The timing circuit 6 supplies a sampling signal to the switch 7 at the moment when the signal SH at the negative terminal of the comparator 2H exceeds the reference signal MH for the first time after SV exceeds the reference signal MV. The switch is turned on for a short time by the sampling signal, so that the instantaneous value of the temperature signal obtained by the infrared detector D in the optical scanning mechanism S and amplified by the amplifier 8 is sampled and the central temperature signal It is stored in the storage circuit 9 as .

10 is turned on only when a vertical flanking signal is supplied from the scanning signal generating circuit 1 via the one-shot multivibrator 11, and the central temperature signal accumulated in the accumulating circuit 9 is transferred to the accumulating circuit 1.
This is a switch that supplies power to 2. The center temperature signal stored in the storage circuit 12 is supplied to the negative terminal of the differential amplifier 13 during the next scanning period. A temperature signal from an infrared detector D is supplied to the positive terminal of the differential amplifier via an amplifier 8. Reference numeral 14 designates the differential amplifier 13 so that when the output level of the differential amplifier 13 is zero (that is, when the temperature signal from the amplifier 8 is equal to the center temperature signal), the Fraun tube shines at the center brightness. This is an output adjustment circuit for adjusting an output signal, and the signal adjusted by the output adjustment circuit 14 is supplied to the cathode ray tube display device 19 as a brightness modulation signal.

In addition, 15H and 15V are analog switches and terminals
Mark position signals MH and MV from the mark position adjustment signal generators 5H and 5V are applied to P ₁ and Q ₁ , respectively.
Terminals P ₂ and Q ₂ are supplied with horizontal and vertical scanning signals SH and SV from the scanning signal generating circuit 1, respectively, and switches SP and SQ are connected to terminals P ₃ and Q ₃ , respectively. These switches SP and SQ are switched by a switching signal generated by a switching signal generating circuit 17 based on a vertical blanking signal from the scanning signal generating circuit 1. The signals sent to terminals P ₃ and Q ₃ are supplied to horizontal and vertical scanning signal input terminals H and V of the display device 19 via amplifiers 16H and 16V, respectively.

In the above configuration, the optical scanning mechanism S receives horizontal and vertical scanning signals SH and SV from the scanning signal generation circuit 1.
The subject 3 is raster-scanned based on. The infrared image signal (temperature signal) obtained from the detector D based on scanning is sent as a brightness signal to the display device 19 via the amplifier 8, differential amplifier 13, and output adjustment circuit 14, and at the same time, the display device 19 is switched on. 1
Since raster scanning is performed based on the horizontal and vertical scanning signals SH and SV sent via 5H and 15V, a temperature distribution image of the subject 3 is displayed on the screen of the display device as shown in FIG. .

Next, a description will be given of means for displaying a mark superimposed on the temperature distribution image of the subject on the display device.

The mark position adjustment signal generators 5H and 5V are composed of potentiometers, for example, and the display device 1
Mark position signals MH and MV specifying the horizontal and vertical positions on the screen of 9 are generated. On the other hand, the switches 15H and 15V are turned to the terminals P ₁ and Q ₁ by the switching signal from the circuit 17 during the vertical retrace period when the temperature distribution image is not displayed. The electron beam of the cathode ray tube remains at a point on the screen designated by the mark position signals MH and MV during the vertical retrace period, and a bright spot, ie, mark 4, is displayed at this point. In this way, the temperature distribution line and the mark are displayed alternately, such as the temperature distribution image during the scanning period and the mark 4 during the vertical retrace period, so that the two are observed with the naked eye as being superimposed.

Next, a means for arbitrarily moving the displayed position of the mark will be explained. Mark 4 above
By operating the mark position adjustment signal generators 5H and 5V while observing the temperature distribution image, the mark can be moved to any desired observation position on the temperature distribution image.

Next, a description will be given of a means for automatically extracting and holding a signal corresponding to the display position of the mark from among the temperature signals.

A comparator 2V receives a mark position signal MV generated from the mark position adjustment signal generator 5V and a vertical scanning signal supplied from the scanning signal generation circuit 1.
SV is compared, and when SV and MV match (that is, when the vertical scanning of the display device 19 and optical scanning mechanism S reaches the position where the mark should be displayed), a match signal is generated.

On the other hand, the comparator 2H receives a mark position signal generated from the mark position adjustment signal generator 5H.
MH is compared with the horizontal scanning signal SH supplied from the scanning signal generation circuit 1, and when SH and MH match (that is, the horizontal scanning of the display device 19 and the optical scanning mechanism S indicates the position where the mark should be displayed). ) generates a match signal.

The timing circuit 6 outputs the timing signal at the moment when a coincidence signal is first generated from the comparator 2H after the coincidence signal is generated from the comparator 2V (that is, when the scanning of the display device 19 and the optical scanning mechanism starts at the mark position signal MH,
the moment the mark position specified in the MV is reached),
Generate sampling pulse. The switch 7 is turned on for a short time by the sampling pulse, and the temperature signal at that moment (that is, the temperature signal corresponding to the mark position) is stored in the storage circuit 9 as a center temperature signal.

The temperature signal corresponding to the mark display position accumulated in the accumulation circuit 9 during the scanning period in this way is generated by the vertical blanking signal from the scanning signal generation circuit 1 being supplied to the switch 10 via the one-shot multivibrator 11. (i.e., during the vertical retrace period), it is transferred to the storage circuit 12 via the switch 10 and stored until the next vertical retrace period.

Next, a description will be given of means for obtaining a difference signal between the temperature signal and the extracted signal. The temperature signal corresponding to the mark display position stored in the storage circuit 12 is the center temperature signal during the next scanning period.
It is supplied to the terminals of the differential amplifier 13 as Vc.
During this scanning period, the amplifier obtains a difference signal between the temperature signal Va from the infrared detector D supplied to its positive terminal and the center temperature signal Vc.

The signal from the means for obtaining the difference signal is applied as a brightness modulation signal to the display device 19 via the output adjustment circuit 14. Therefore, the temperature distribution image of the subject is displayed on the screen of the display device 19, with the temperature signal corresponding to the mark display position from the storage circuit 12 being the center temperature signal (signal giving the center of the brightness level). The area indicated by the mark is displayed at the center brightness, allowing you to observe that area in detail.

If a center level display device 18 for monitoring and displaying the signal stored in the storage circuit 12 is connected, the level of the center temperature signal can be grasped, which is convenient for operation.

Further, in the above embodiment, the mark is displayed during the vertical retrace period, but by supplying the horizontal blanking signal to the circuit 17, the switches 15H and 1
If the voltage of 5V is switched to the P ₂ and Q ₂ sides during the horizontal retrace period, the mark is displayed every horizontal period, so that flickering of the mark can be reduced.

Furthermore, by increasing or decreasing the brightness of the display device 19 for a short time using the sampling pulse from the timing circuit 6, a bright spot or a dark spot is displayed as a mark at the position on the subject image where the temperature signal is sampled. be able to. In this way, the mark can be displayed during the scanning period, so
Switches 15H, 15V and circuit 17 are no longer necessary.

Further, in the above embodiment, a bright spot is displayed as a mark, but any mark can be used as long as the position can be specified. For example, if a crosshair is used, higher visibility than a dot can be expected.

Furthermore, the present invention can also be applied to a thermography device that has an image memory upstream of a display device and stores temperature signals once and then supplies them to the display device.

[Effects] As detailed above, in the present invention, an arbitrarily movable mark is displayed on a display device, and the temperature signal of the object part corresponding to the mark display device is automatically extracted as a center temperature signal. The difference between the temperature signal obtained by optically scanning the object and the temperature signal corresponding to the retrieved mark display position is supplied to the display device as a brightness modulation signal, so it is possible to perform the observation specified by the mark. parts are maintained at optimal brightness levels.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an example of a thermography apparatus embodying the present invention, and FIG. 2 is a diagram for explaining a temperature distribution image of a subject and marks displayed on the screen of a display device. S: optical scanning mechanism, D: infrared detector, 1:
Scanning signal generation circuit, 2H, 2V: comparator,
3: Subject, 4: Mark, 5H, 5V: Mark position adjustment signal generator, 6: Timing circuit, 7, 1
0: Switch, 9, 12: Storage circuit, 11: One-shot multivibrator, 13: Differential amplifier, 14: Output adjustment circuit, 15H, 15V: Analog switch, 17: Switching signal generation circuit, 19:
Display device.

Claims (1)

[Claims] 1. A thermometer that optically scans a subject to detect infrared rays emitted from each part of the subject, and displays a temperature distribution image of the subject on a display device based on a temperature signal obtained by detecting the infrared rays. In the graphie device, means for displaying a mark superimposed on the subject image on the display device, and means for arbitrarily moving the display position of the mark;
Means for automatically extracting and holding a signal corresponding to the display position of the mark from among the temperature signals, and means for obtaining a difference signal between the temperature signal and the extracted signal, A thermography apparatus characterized in that a difference signal is introduced into the display device so that the image is displayed with the part of the image corresponding to the mark as the central brightness.