JPH0311154B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a temperature distribution image reproducing device that generates an infrared image signal using a pyroelectric infrared vidicon and a chopper that periodically cuts off infrared rays incident on a target of the vidicon. The purpose of this method is to correlate the shape of the object to be measured and the temperature distribution area from the reproduced image so that the image can be interpreted correctly.

A temperature distribution image of an object to be measured is generally reproduced two-dimensionally on a television screen or a hard copy. However, the resolution of these images is poor, and it is often difficult to understand the positional relationship of the temperature distribution to the object to be measured.

The correspondence between the temperature distribution image of the measured object obtained from the infrared region and the object has already been achieved by directly mixing the reconstructed image of the infrared camera and the reconstructed image of a separate visible camera, and then reproducing and displaying the two, and relating the two. Proposed.

For example, the method described in JP-A-53-118309 is one of them. That is, a positive photograph of the object to be measured is separately prepared, and at the same time the object to be measured is reproduced with an infrared television camera, the positive photograph is imaged with a separately prepared visible camera, and the reproduced signal is mixed with the infrared camera reproduced signal. In this method, the images are displayed in a superimposed manner on the television monitor. According to this method, the infrared image expressed in black and white shading is displayed with the black and white shading of the visible image superimposed, making it easy for errors to occur in interpreting the temperature distribution using infrared rays. Furthermore, the interpretation of temperature distribution is likely to be adversely affected by shearing components included in the visible camera signal.

Another proposal is a method described in Japanese Patent Application Laid-Open No. 51-24281. That is, this is a method in which infrared reproduced images are displayed in color in advance for each temperature level, and a visible image is multiplexed thereon. However, even with this method, it may be difficult to accurately display the temperature distribution regardless of the contrast strength of the visible image. For example, to display the color of the object to be measured, the brightness and darkness of the visible image are added to the brightness and darkness of the infrared image. If the difference between the two is large, there will be a difference in brightness even in parts of the same hue in one screen, and if the hue stage is divided into about ten or more colors, there will be a drawback that the hue will be misinterpreted.

The present invention seeks to eliminate the above-mentioned drawbacks.

In other words, in a device that reproduces a temperature distribution image using a pyroelectric infrared vidicon and a chopper that periodically blocks infrared rays incident on the target of this vidicon, a video signal obtained in the infrared region is added to a video signal obtained from visible light. The image is reproduced by superimposing photoelectrically converted object contour signals and the like. In this case, the temperature distribution image can always clearly reproduce the shape of the object to be measured and the positional relationship between the temperature distribution and the object, and at the same time display isothermal areas with equal brightness, making it possible to obtain accurate temperature data.

FIG. 1 shows the configuration of an embodiment of the present invention in which a pyroelectric vidicon and a visible light vidicon are scanned in synchronization, and the contour signals of a temperature distribution image and a visible light image are multiplexed and displayed. .

In the figure, 1 is an object to be measured, and 2 is an infrared lens for imaging the object to be measured, which forms an image of the object to be measured 1 on the target surface of a pyroelectric vidicon 4. 3
The cutter periodically blocks the incident light from the lens 2. As a result, charges corresponding to temperature changes on the target are generated, making it possible to reproduce a temperature distribution image of a stationary object.

5 is a video amplifier that inputs the infrared signal from the target and amplifies it to about 0.3V _pp .

The scanning beam of the pyroelectric vidicon 4 is electromagnetically focused and electromagnetically deflected by a deflection circuit 6 and a yoke coil 6'.

Reference numeral 7 denotes a synchronization signal generation circuit which supplies horizontal and vertical synchronization pulses to the deflection circuits 6 and 13, a composite synchronization signal to the mixing circuit 23, and a chopper synchronization reference pulse to the chopper synchronization circuit 8. Note that 13 is a deflection circuit for the visible light vidicon 12, which will be described later.

To synchronize the chopper, the chopper position is detected by the light emitting diode 10 and the phototransistor circuit 9, and the output signal thereof and the chopper synchronization reference pulse are applied to the chopper synchronization circuit 8, and the chopper is synchronized by phase comparison detection.

A visible light imaging lens 11 forms an image of the object to be measured 1 on the target surface of a vidicon 12 whose target material is Sb ₂ S ₃ or Si for visible light. Beam scanning of the visible light vidicon 12 is performed by the deflection circuit 13 and yoke coil 13', as in the case of the pyroelectric vidicon 4 described above.

The visible image output signal is amplified by an amplifier 14 and has a waveform 1.
5 is applied to the contour pulse signal generation circuit 16. The contour pulse generation circuit 16 has a differentiating circuit configuration and generates the contour of the visible image by extracting a signal component having a large luminance change from the visible image output signal. Furthermore, in the comparison circuit, positive and negative pulses 17 and 18 of 5V _pp and -5V _pp are applied to the contour pulse modulation circuit 19, with only signals above a certain level being used as contour signals.
In the contour pulse modulation circuit 19, the chopper synchronous control pulse 20 is generated by the chopper synchronous control pulse 20.
Contour multiplex signal of positive and negative alternation so that when is "H" (infrared video signal is on the hour), it is a positive contour pulse signal, and when it is "L" (infrared video signal is negative), it is a negative contour pulse signal. 21.

Even if the signal 21 is a positive or negative signal, it is sufficient to achieve the purpose. 20 is a chopper synchronous control pulse.

23 is a contour signal 21 and a temperature distribution image signal 22;
This is an addition circuit that mixes the composite synchronization signals obtained from the synchronization signal generator 7 and the synchronization signal generator 7. The temperature distribution image of the object to be measured is multiplexed with contour signals, sent to an image processing device from an output terminal 24, and displayed on a color monitor.
25 is the output waveform of the output terminal 24.

FIG. 2 shows the signal processing method of the image device. After being converted into a digital signal via the A/D converter 26, the positive polarity signal ( (hereinafter abbreviated as p signal) and negative polarity signal when closed (hereinafter abbreviated as n signal)
further stored in each positive frame portion 28 and negative frame 29 and subjected to calculation processing such as average calculation,
After the subtraction processing section 30 performs subtraction processing on both signals, the pseudo color conversion section 31 converts the signal into a pseudo color signal according to the signal level, and the D/A conversion section 32 converts it into an analog signal, which is displayed on the monitor 33. The above signal processing is a method of displaying the positive and negative signals of the infrared video signal obtained by opening and closing the chopper as a flicker-free signal. In this embodiment, the contour signal superimposed on the temperature distribution image is similarly processed through the image processing device shown in FIG.

In addition, for the part displayed by another information signal such as the above-mentioned contour signal, the image obtained in the above-mentioned infrared region may be displayed multiple times in a color other than the hue displayed corresponding to the absolute temperature, or in white or black. You can also do it.

The above embodiment is a method of directly multiplexing the contour signal onto the thermal image signal and storing or reproducing it. However, in order to obtain the thermal image signal, the chopper opening/closing signal (8 fields open, 8 fields closed) is used to turn on and off the chopper. Create 1 empty field in each field, Part 1
A contour signal may be superimposed on the field. FIG. 3 shows a waveform diagram at this time. In Fig. 3, waveform a is a chopper opening/closing signal pulse, and this pulse forms a gate pulse (waveform b) that extracts only one field, and when a continuously transmitted contour signal is extracted with the gate pulse, the waveform This results in the contour signal shown in c. Furthermore, by adding the thermal image signal (waveform d: signal extraction method omitted), which has no signal only at the position of the gate pulse (waveform b), and the contour signal c, waveform e is obtained. Furthermore, if the contour signal c is made a negative signal, a waveform f is obtained. Furthermore, the contour signal c may be synchronized with the opening/closing signal of the chopper to be used as a positive/negative signal. Similar effects can be obtained by outputting these waveforms e or f from the output terminal 24 in FIG.

In this case, if the waveforms e and f are directly reproduced, the contour image will flicker, resulting in a defect that is difficult to observe.However, if only the contour signal is separated before reproduction and once passed through the memory circuit, this defect can be removed, and the contour signal can be uniformized. This is effective when displaying with a certain hue. This embodiment is particularly effective when displaying in color.

As described above, the present invention repeats the opening and closing of the chopper that modulates the infrared rays incident on the pyroelectric infrared vidicon every eight fields of television scanning. , a positive signal is obtained when the chopper is open, a negative signal is obtained when it is closed), and a positive and negative contour signal (i.e., a single signal) is obtained every 8 fields synchronized with the opening and closing of the chopper to the infrared image signal that is generated alternately between positive and negative synchronized with the chopper. This system displays an image by superimposing an alternating pulse (which changes positive or negative on each screen) onto an infrared image signal, and has the following effects.

(i) Even for complex temperature distribution images, images with small temperature differences and low contrast ratios, contour information is displayed multiplexed, making it easier to understand the relationship between the shape of the object and the temperature distribution area.

(ii) Since the contour signal does not affect the contrast of the temperature distribution region, the equal temperature distribution range can be read accurately.

(iii) Since it is possible to invert the polarity of the contour signal and change the amount of contour information depending on the degree of contrast of the temperature distribution image, analysis of infrared images can be easily performed.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a temperature distribution image reproducing device in one embodiment of the present invention, FIG. 2 is a block diagram showing an image processing method of the present invention, and FIG. 3 is a signal waveform diagram in another embodiment of the present invention. It is. 1...Object to be measured, 2...Infrared imaging lens,
3... Chotsupar, 4... Pyroelectric infrared vidicon, 5... Video amplifier, 5... Deflection circuit for infrared vidicon, 6'... Yoke coil, 7... Synchronization signal generator, 8... Chotsupa synchronous circuit , 9... phototransistor circuit, 10... light emitting diode,
11... Visible imaging lens, 12... Vidicon, 1
3...Deflection circuit, 13'...Yoke coil, 14
...Video amplifier, 16...Contour signal generation circuit, 1
9... Chopper contour pulse modulation circuit, 23...
Addition circuit, 24... Output terminal, 26... A/D converter, 27... Positive/negative signal switching section, 28... Positive frame memory, 29... Negative frame memory, 30... Subtraction processing section, 31... Pseudo color converter, 32...D/A converter, 33...monitor.

Claims (1)

[Claims] 1 comprising a pyroelectric infrared vidicon, a chopper that periodically blocks infrared rays incident on a target of the pyroelectric infrared vidicon, and a visible light vidicon that images approximately the same field of view as the pyroelectric infrared vidicon; An infrared image signal is generated by converting the visible contour signal of the object obtained from the visible light vidicon into an alternating pulse that changes positive and negative for each screen in synchronization with the rotation of the chopper, and generates an alternating positive and negative pulse synchronized with the chopper of the pyroelectric infrared vidicon. In addition to this, a temperature distribution image reproducing device is characterized in that it displays an image of a signal difference between a bipolar screen.