JPH0215006B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thermography device that can obtain a temperature distribution image of a stationary state at any phase of the period of a subject whose temperature changes or moves periodically in a short period. .

In a thermography device, an image spot of an infrared detector is formed on a subject, the image spot is raster scanned, and an infrared image signal obtained from the detector is sent to a display means as a result of scanning, and the temperature of the subject is determined. I'm trying to get a distribution image. However, since this scanning is done mechanically using mirrors, etc., it is not possible to increase the speed beyond a certain level, and with a horizontal scanning period of 1/120 seconds and 240 scanning lines, it takes about 2 seconds or more to scan one screen. is unavoidable. 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,
horizontal scanning means for repeatedly horizontally scanning the 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. The present invention provides a thermography apparatus capable of obtaining 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 an object rotated by a motor 3, and 4 is an image spot Z of the detector 1. This is a lens for forming an image on the subject 2. The image spot Z is horizontally and vertically scanned on the subject 2 by an optical scanner 5, and the infrared image signal obtained from the detector 1 is transmitted through an amplifier 6, a processing circuit 7 including a linearizer, etc., and a conversion circuit 8. Video tape recorder (VTR)
9 is supplied to video input terminal A. Said motor 3
generates a synchronization signal S synchronized with the rotation, and the synchronization signal S is sent to the audio input terminal B of the VTR 9 and recorded, and is also sent to the vertical scanning circuit 10 for vertical scanning of the optical scanner 5. . Reference numeral 11 denotes a horizontal scanning circuit for horizontal scanning of the optical scanner 5.

During playback, the synchronizing signal S taken out from the audio output terminal B' of the VTR 9 is sent to the cathode ray tube (CRT) display device 12.
It is sent as a signal to advance vertical scanning by one step. Further, the video signal taken out from the video output terminal A' of the VTR 9 is also sent to the CRT display device 12 via the inverse conversion circuit 13 and the gate circuit 14.
15 separates the horizontal synchronizing signal h from the video signal,
a synchronous separation circuit for sending to the CRT display device 12;
A variable delay circuit 16 generates a gate signal that opens the gate circuit 14 for one horizontal scanning period after a predetermined time from the synchronizing signal S taken out from the audio output terminal B'.

In the above configuration, the optical scanner 5 repeatedly performs horizontal scanning at a period of 1/120 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 object 2 is rotating at 10Hz (period: 100mS) as shown in Figure 2a, horizontal scanning will be performed 12 times during one period as shown in Figure 2b. If the synchronization signal S is generated every 100 mS as shown in c in the same figure, then the vertical scanning is also synchronized with the synchronization signal S as shown in d in the figure, and the horizontal scanning is 12 times as shown in d in the same figure.
You will advance one step each time. The video signal shown in FIG. 5e obtained as a result of such scanning is converted by the converter 8 into a form that can be recorded on the VTR 9 and sent to the VTR 9.

Here, regarding the 12 video signals Va, Vb, Vc, ...Vk, Vl obtained during one rotation of the subject, considering the scanning direction and the orientation of the subject 2 when each video signal was acquired, Fig. 3 As shown, for a constant scanning direction (solid arrow), a→b→c→……→k→
The phase is shifted from l 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, if the video signals Va, Va', .
The object image has a phase shown by . If the video signals Vb, Vb'... obtained in the second horizontal scan are extracted, the object image with the phase indicated by b in Fig. 3 can be obtained, and if the extraction timing is set appropriately, the images from a to l in Fig. 3 can be obtained. A temperature distribution image of a subject at any phase can be created.

The output terminals A' and B' of the VTR 9 in FIG. 1 are connected to a configuration for extracting a video signal and displaying an image as described above. That is, during playback of the VTR 9, the video signal shown in Figure 2e is sent from the inverse conversion circuit 13, which performs the opposite conversion to that of the conversion circuit 8, and the synchronization signal S shown in Figure 2c is sent from the terminal B', with the time relationship unchanged. will be played. The display device 12 displays the second signal based on the horizontal synchronizing signal h separated by the separation circuit 15.
Horizontal scanning is carried out exactly as in FIG. 2b, and vertical scanning is stepped in exactly the same manner as in FIG. 2d by the reproduced synchronizing signal. And the variable delay circuit 16 is
When it is desired to obtain an image with the phase shown in FIG. 3a, a gate signal covering one horizontal scanning period is generated with a delay of ta from the synchronizing signal S as shown in FIG. 2f, and the gate circuit 14 is opened for that period. 12 is a video signal
Va, Va', . . . are transmitted, and the object image having the phase shown in FIG. delay time
It goes without saying that if ta is set appropriately, images of any phase shown in FIGS. 3a to 1 can be obtained. At that time, by increasing the delay time step by step and displaying the images sequentially as a→b→c→...→l in Fig. 3, it is possible to display a temperature distribution image of the subject like a decomposed photograph. can.

In the above embodiment, the subject rotates, but even when the subject moves periodically, that is, vibrates,
Furthermore, even when the temperature changes periodically, it is possible to obtain an image of the object at any phase of the period; in short, any object that shows periodic changes can be used.

In addition, in the above embodiment, since a VTR 9 was used, the synchronization signal S was recorded on the audio channel, but when using other recording means such as a data recorder, it is necessary to reserve one channel for the synchronization signal. Needless to say.

[Brief explanation of drawings]

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: VTR, 10, 11: Power supply,
12: CRT display device, 14: Gate circuit, 1
5: Synchronous separation circuit, 16: Variable delay circuit.

Claims (1)

[Claims] 1. An infrared detector, horizontal scanning means for repeatedly horizontally scanning the 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; an infrared image signal obtained from the detector during scanning by the horizontal and vertical scanning means; and a synchronization signal synchronized with changes in the subject. A storage means for simultaneously storing data, a means for extracting a video signal having a specific phase relationship with the synchronizing signal from among the video signals stored in the storage means, and a display means to which the extracted video signal is supplied. A thermography device characterized by: