JPS58151531A - Thermography device - Google Patents

Abstract

PURPOSE:To obtain a temperature distribution image of a static state of an object to be photographed, which moves or is varied in its temperature periodically at a short period, by executing horizontal scanning and vertical scanning repeatedly at a sufficiently shorter period than a variation period of the object to be photographed, and fetching and displaying a video signal having a specified phase relation. CONSTITUTION:An optical scanner 5 executes horizontal scanning by a horizontal scanning circuit 11, and when a synchronizing signal S is generated, vertical scanning is advanced by 1 step by a vertical scanning circuit 10. A video signal is converted by a converter 8 to send to a VTR9. When reproducing the VTR9, the video signal and the synchronizing signal S are reproduced from a reverse converting circuit 13 for executing the reverse conversion to the converting circuit 8, and a terminal B', respectively, in a state that each time relation remains as it is, and a variable delaying circuit 16 generates a gate signal in delaying by ta from the synchronizing signal to open the gate circuit 14. To a display 12, the video signal obtained by one time horizontal scanning is sent, and an image of an object to be photographed having its phase is displayed. When the delay time ta is set suitably, an image of optional phase is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thermography apparatus capable of obtaining a temperature distribution image of a stationary state at any phase of the period of an object whose temperature changes or moves periodically in a short period. be.

In a thermography device, an image spot of an infrared detector is formed on a subject, the image spot is scanned in a rask, and an infrared image signal obtained from the detector is sent to a display means as a result of scanning, and a temperature distribution image of the subject is displayed. I'm trying to get it. However, since this scanning is performed mechanically using mirrors, etc., it is not possible to increase the speed beyond a certain level, and the horizontal scanning period is 1/120 seconds, and the scanning rate is 1/240 lines.
It is unavoidable that screen scanning takes about 2 seconds or more.

Therefore, conventionally, a temperature distribution image could not be obtained unless the subject was in a stationary state or nearly so, and the subject had almost no temperature change.

The present invention has been made in view of this point, and is a horizontal-scanning method for repeatedly horizontally scanning the image spot of a detector on a subject that is periodically moving or temperature-controlled at a cycle sufficiently shorter than the above-mentioned cycle. means, vertical scanning means for vertically scanning the image spot in synchronization with changes in the subject, an infrared image signal obtained from the detector in conjunction with scanning by the horizontal and vertical scanning means; Storage means for simultaneously storing a synchronization signal synchronized with changes in a subject; means for extracting a video signal having a specific phase relationship with the synchronization signal from among the video signals stored in the storage means; and the extracted video signal. The present invention provides a thermography apparatus that can obtain a temperature distribution image in a stationary state at any timing. The present invention will be explained in detail below using the drawings.

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention. In the figure, 1 is an infrared detector, 2 is a subject rotated by a motor 3, and 4 is a block diagram showing an image spot Z of the detector 1 on the subject 2. This is a lens to form an image on top. The image spot Z is horizontally and vertically scanned on the subject 2 by the optical scanner 5, and the infrared image signal obtained from the detector 1 is sent to the amplifier 6. The signal is supplied to a video input terminal A of a video tape recorder (VTR) 9 via a processing circuit 7 including a linearizer and the like and a conversion circuit 8. The motor 3 generates a synchronization signal S synchronized with its rotation, and the same I! l signal S is VTR9
The signal is sent to the audio input terminal B of , where it is recorded, and is also sent to the vertical scanning circuit 1o for vertical scanning of the optical scanner 5. 11 is a horizontal scanning circuit for horizontal scanning of the optical scanner 5;

The synchronizing signal S taken out from the audio output terminal B' of the VTR 9 during playback is a cathode ray! ! (CRT) The signal is sent to the display device 12 as a signal for advancing vertical scanning by one step. Further, the video signal taken out from the video output terminal of the VTR 9 is also transferred to the inverse conversion circuit 13. The signal is sent to the CRT display device 12 via the gate circuit 14. 15 is a sync separation circuit for separating the horizontal sync signal from the video signal and sending it to the CRT display device 12; 16 is a sync separation circuit for separating the horizontal sync signal from the video signal and sending it to the CRT display device 12; This is a variable delay circuit that generates a gate signal that opens the gate circuit 14 for one horizontal scanning period.

In the above-described configuration, the optical scanner 5 repeatedly performs horizontal scanning at a cycle of 1A120 seconds by the horizontal scanning circuit 11, and this horizontal scanning is repeated at the same position until the synchronization signal S is generated. When the synchronizing signal S is generated, the vertical scanning circuit 10 advances the vertical scanning by one step, so that the horizontal scanning is repeated again at the next position shifted by one scanning line.

Therefore, if subject 2 is 10)-12 (period: 100m5
) is rotating as shown in Figure 2 (a), then
Horizontal scanning is performed 12 times during one period as shown in (b) of the same figure, and if the synchronization signal S is generated every 100,118 times as shown in (c) of the same figure, vertical scanning In synchronization with this, as shown in FIG. 3(d), one step is advanced every 12 horizontal scans. The video signal shown in FIG. 5(e) obtained through such scanning is converted by the converter 8 into a form that can be recorded on the VTR 9, and is sent to the VTR 9.

Here, 12 video signals V obtained during one rotation of the subject
a,, Vb, Vc, ---Vk, Vl, considering the scanning direction and orientation of subject 2 when acquiring each video signal, the scanning direction is constant (solid arrow) as shown in Fig. 3. For, (a)→(b)→(C)→...→(1()→
The phase is shifted from (1) by 360°/12=30°. Then, during the next rotation of the subject, horizontal scanning is performed 12 times at exactly the same timing at a position shifted by one scanning line (indicated by a broken line in Figure 3), and in the same manner, scanning is performed every other rotation of the subject. Horizontal scanning is performed by shifting the position one line at a time. Therefore, the video signals va, va-... obtained in the first horizontal scan after the vertical scan is advanced by one step.
. If an image is formed by extracting . 2
1st horizontal scan 'C - Obtained video signals vb, vb
By extracting '..., you can obtain an image of the object at the phase indicated by b in Figure 3, and if you set the extraction timing appropriately, you can create a temperature distribution image of the object at any phase from a to 1 in Figure 13. be able to.

The configuration for extracting a video signal and displaying an image as described above is connected to the output terminals A- and B- of the VTR 9 in FIG. That is, during playback on the VTR 9, the inverse conversion circuit 13, which performs the opposite conversion to the conversion circuit 8, outputs the signal as shown in FIG. 2(e).
The video signal shown in FIG. 1 is reproduced from terminal B', and the synchronization signal S shown in FIG. Display device 1
2 performs horizontal scanning exactly as shown in FIG. 2(b) based on the horizontal synchronizing signal separated in the separation circuit 15, and performs vertical scanning as shown in FIG. 2(d) using the reproduced synchronizing signal.
) is incremented in exactly the same way. and variable delay circuit 16
When it is desired to obtain an image with the phase shown in Fig. 3a, it emits a gate signal that covers one horizontal scanning period by taM from the synchronizing signal S, as shown in Fig. 2(f), and opens the gate circuit 14 for that period. Therefore, the display device 12 displays video signals Va, Va-,
. . , and therefore the object image having the phase shown in FIG. 3a is displayed. If the delay time [a is set appropriately,
It goes without saying that images of any phase shown in FIGS. 3a to 1 can be obtained. At that time, if the delay time is increased step by step and the images are displayed sequentially as a-+b-+c→...→1 in Fig. 3, a temperature distribution image of the subject can be displayed like a decomposed photograph. Can be done.

Although the above embodiment deals with a case in which the subject is rotating, it is possible to obtain an image of the subject at any phase of the period even if the subject is in periodic reciprocating motion, that is, vibrates, or if the temperature changes periodically. In short, any object that shows periodic changes may be used.

Also, in the above embodiment, since VTR9 was used, the synchronization signal S
However, when using other recording means such as a data recorder, it goes without saying that it is necessary to reserve one channel for the synchronization signal.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention, FIG. 2 is a waveform diagram for explaining its operation, and FIG. 3 is a diagram for explaining the relationship between the orientation of the subject and the scanning direction. It is. 1: Infrared detector, 2: Subject, 3: Motor, 5: Optical scanner, 9: VTR110, 11: Power supply, 12: C
RT display device, 14: gate circuit, 15: synchronous separation circuit, 16: variable delay circuit.

Claims (1)

[Claims] an infrared detector; horizontal scanning means for repeatedly horizontally scanning an image spot of the detector on a subject that is periodically moving or changing temperature at a cycle sufficiently shorter than the above-mentioned cycle;
Vertical scanning means for vertically scanning the image spot in synchronization with changes in the object, and an infrared image signal obtained from the detector in conjunction with scanning by the horizontal and vertical scanning means, synchronized with changes in the object. a storage means for simultaneously storing a synchronization signal, a means for extracting a video signal having a specific phase relationship with the synchronization signal from among the video signals stored in the storage means, and a display to which the extracted video signal is supplied. A thermography device characterized by comprising: means.