JPH10332489A - Thermography device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make understandable a preset emissivity temperature value and corrected emissivity temperature value immediately by digitally indicating the temperature value based on the preset emissivity and the corrected emissivity by specifying that part even when there is the part of different emissivity in a subject when infrared energy from the subject is detected with a thermography device. SOLUTION: An index (cross cursor) can be moved to an appropriate position with an index moving key 34 in the temperature distribution image displayed on the screen of the thermography device 20. At the same time, a corrected emissivity setting circuit 23 is provided, and the emissivity can be set. When the above described index is moved to the part having the different emissivity, the preset emissivity and the temperature value, which is corrected with this preset emissivity, are digitally displayed in the vicinity of the index.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermographic apparatus which detects infrared rays from a subject and displays a temperature distribution in color on a display device screen, and more particularly to an emissivity of a specific area in a temperature distribution image. The present invention relates to an improvement of a thermographic device capable of correcting the temperature.

[0002]

2. Description of the Related Art Generally, in a thermographic apparatus,
The infrared energy radiated from the object depending on the temperature is detected, and the obtained temperature signal is transmitted as a luminance signal to a display device such as a CRT (cathode ray tube) to obtain a temperature distribution image of the subject. . In such a thermography apparatus, since the emissivity ε of the subject differs depending on the substance, it is inevitable that a temperature error occurs, and usually an emissivity correction circuit is provided.

The above-described conventional emissivity correction circuit captures infrared light from a subject through a camera and corrects the entire temperature distribution image displayed on the screen of the display device with the same emissivity ε _O , for example. It was made in

However, if the correction is made with the same emissivity ε _o for one entire screen in this way, the emissivity ε _{O in the} subject
Different if there is emissivity with epsilon _a region, since an error occurs in the temperature values obtained for that region, as can be corrected for emissivity of any region in the temperature distribution image formation Japanese Patent Laid-Open No. Hei 3-2250
No. 6,086,045.

In the above publication, as shown in FIG. 5, a center temperature 25 and a temperature range 2 are displayed on a screen 24 of a display device 11 such as a CRT.
6 is displayed in characters, the area of the temperature distribution image 27 and the frame 28 are designated, and the emissivity is corrected only for the pixels included in the area defined by the frame 28 to display the color temperature.

[0006]

The conventional thermographic device disclosed in the above publication takes in temperature data detected by an infrared detector into an image memory and corrects the corrected data obtained by performing the emissivity correction by an emissivity correction circuit. Since the data writing circuit is used to write and read data again in the frame specified area of the image memory, a frame setting circuit for specifying the area, a frame writing circuit, a frame display memory, and the like are required, and the circuit becomes complicated. , requires a lot of circuit components, there is a problem that can not be a direct view whether it is what kind of value emissivity ε _o is within the frame of emissivity correction has been performed.

An object of the present invention is to provide a thermographic apparatus which has solved the above-mentioned problems. The problem to be solved by the present invention is that the frame setting is not performed and the thermographic apparatus is frequently used for a display apparatus of a thermographic apparatus. The color temperature distribution image is displayed by correcting the emissivity at the specified point of the index (cross cursor) in the image, and displaying the corrected emissivity temperature value and the set emissivity in the vicinity of the cursor specified point. The emissivity set for the portion where the correction has been made and the temperature value corrected for the emissivity are immediately known.

[0008]

As shown in FIG. 1, the thermographic apparatus of the present invention corrects the emissivity of the entire screen based on temperature data obtained by detecting infrared energy from a subject 1 as shown in FIG. In the thermography apparatus 20 which displays the temperature distribution image of the subject 1 by means of a digital camera, the temperature value of the corrected emissivity at the indicated point position and the set emissivity are displayed in the vicinity of the indicated point position of the index of the temperature distribution image. It is made to do.

According to the thermographic apparatus of the present invention, emissivity correction can be performed in real time or in a frozen state,
Since it is not necessary to make the emissivity at the position where the corrected emissivity is set and the temperature value of the corrected emissivity correspond to each other on the screen, it is possible to obtain a thermographic apparatus having a display method that is extremely easy to understand.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the thermographic apparatus according to the present invention will be described below in detail with reference to FIGS.

FIG. 1 is a system diagram of a thermographic apparatus according to the present invention, FIG. 2 is an external view of a main body except for a camera section, FIG. 3 is a screen example of the present invention, and FIG. 4 is an operation flowchart. In FIG. 1, infrared rays emitted from a subject 1 are focused on an infrared ray detector 3 by an optical scanner 2 that performs raster scanning through a window 2a, and infrared rays are detected. The detector 3 has a chopper and a standard black body for guiding a reference infrared ray into the detector 3 every horizontal scanning of the optical scanner 2, and detects light reflected from the standard black body when the chopper is cut off. The output signal of the detector 3 is output as an AC signal proportional to the energy difference between the incident infrared ray and the standard black body.

[0012] Such a weak AC signal is supplied to an operational amplifier (A
MP), amplified by a signal synchronized with the chopper, averaged through a low-pass filtering circuit or the like, and an analog output signal is supplied to an analog-to-digital conversion circuit (A / D) 5 to be converted into digital data. After the conversion, it is supplied to an entire screen emissivity correction circuit 6 for correcting the emissivity ε _O of the entire screen. The whole screen emissivity correction circuit 6 is included in a processing circuit including an absolute temperature reproducing unit and a linearizer, and the image data is converted into a temperature signal corresponding to the absolute temperature. Further, the entire screen emissivity setting circuit 42 is configured to perform the entire correction of the entire screen emissivity correction circuit by operating the entire screen emissivity setting key 43.

The emissivity of a substance or an object varies from 0.01 to 1 depending on the ambient temperature of the substance and the difference between the substance and the object. For example, 50 ° C.-1
0.04 to 0.06 at 00 ° C, 20 ° C to 10 for glass
It shows values such as 0.94 to 0.91 at 0 ° C. Usually, the emissivity ε _o = 1 is often selected in the entire screen emissivity correction circuit 6.

The output temperature data of the entire screen emissivity correction circuit 6 is sent to the image memory 9 via the switching means 8 and stored in the image memory 9. When the switching means 8 is turned on, the emissivity can be corrected in a frozen state based on data stored in an image memory 9 to be described later in real time when the switching means 8 is turned off. The switching means 8 is controlled by a data acquisition control circuit 7 constituted by a microcomputer (hereinafter referred to as a CPU).

The image memory 9 has a storage capacity of at least one frame, and is rewritten every scan of one frame.

The temperature data stored in the image memory 9 and corrected at the same emissivity on the entire screen is included in the CPU 7.
The pixel data is read out via a readout circuit or a write circuit (not shown) and stored in the display memory 10 in a form that fits in the gradation of the display device 11 such as a CRT for monitoring. Is transmitted to the display device 11 via a display drive circuit or the like, and displays a temperature distribution image 27 (see FIG. 3) on the screen 24 of the display device 11.

In FIG. 1, an image memory point setting circuit 12 is a setting circuit including an operation unit for setting an index (hereinafter referred to as a cross cursor) 30 on a screen 24 of the display device 11 as shown in FIG. As shown in FIG. 2, the camera unit having the optical scanner 2 is separated from the A / D conversion circuit 5, and the circuits indicated by reference numerals below are disposed in a casing 32 of a main body 31 of the thermographic apparatus 20. The cross cursor 30 can be moved to an appropriate position on the screen 24 of the display device 11 by the index movement key 34 provided above.

When the position of the cross cursor 30 is designated by the index movement key 34, the designated position is converted to a predetermined address in the image memory 9 via the address decoder 13, and the address of the position of the cross cursor 30 is stored in the image memory 9.
Is stored.

The calibration circuit 14 includes a calibration key 3 on the panel 33.
And a calibration circuit (CAL data) 15 which is measured by the calibration circuit 14 and is supplied to the whole image emissivity correction circuit 6, the subtractor 17 and the adder 19. Supplied.

Based on the CAL data 15, the emissivity is corrected by the emissivity ε _O of the entire screen emissivity correction circuit 6.

Further, the image data at the position of the cross cursor 30 set by the image memory setting circuit 12 is fetched into the buffer memory 16 and supplied to the subtracter 17 so that the calibration circuit 1
The CAL data 15 measured in step 4 is subtracted from the emissivity ε _O data corrected by the entire screen emissivity correction circuit 6.

The subtraction data obtained by the subtractor 17 is supplied to a multiplier 18 at the next stage. The subtraction output data from the multiplier 18 is multiplied by the corrected emissivity data 22 set by the corrected emissivity setting circuit 23.

When the emissivity setting key 37 of the correction emissivity setting circuit 23 is pressed, a ten key 39 or the like is displayed on the screen 24 of the display device 11 as shown in FIG. , A predetermined emissivity ε _b may be specified.

The multiplied data of the multiplier 18 is supplied to an adder 19 and added to the CAL data 15. The added data of the adder 19 is supplied to a temperature value and emissivity value display circuit 21, and the CRT of the display device 11 is provided. Supplied to

As shown in FIG. 3, a screen 24 such as a CRT of the display device 11 displays the corrected emissivity setting circuit 23 at the position of the cross cursor 30 moved by the index moving key 34 of the image memory point setting circuit 12. The emissivity peculiar to the object, for example, the true emissivity and the emissivity of the sunlit window glass and the shaded window glass in the color temperature distribution image 27 of the building in FIG. 3 are corrected. The displayed temperature value is displayed as a digital display value 40 near the cross cursor 30.

Therefore, the observer of the temperature distribution image 27 can immediately visually recognize the corrected temperature and the corrected emissivity in the image.

In the above system diagram of FIG. 1, the subtractor 16,
Although the multiplier 18, the adder 19, and the like are shown in a hardware configuration, the processing may be performed by software by the CPU 7 included in the data capture control circuit 7.

In the case of processing by the CPU 7, for example, the emissivity ε of the subject 1 is set to ε _O by the entire screen emissivity correction circuit 6 in FIG. 1, and the true temperature of the subject 1 is set to f.
(T _o) and then, the environmental temperature that is reflected from the object 1 f
(T _a ), the environmental temperature f (T _a ) around the subject
Is represented by (1−ε) × f (T _a ). Therefore, the temperature data of the image taken into the image memory 9 is expressed by the equation (1). (Ε / ε _O ) × f (T _o ) + (1−ε / ε _O ) × f (T _a ) = (ε / ε _O ) × {f (T _o ) −f (T _a )} + f ( T _a ) ‥‥‥ (1) where f (T _a ) is the CAL data 15 in FIG. 1, and the corrected emissivity in the corrected emissivity setting circuit 23 is ε _a. Converted into the formula, (ε _O / ε _a ) × (ε / ε _O ) × {f (T _O ) −f (T _a )} + f (T _a ) = (ε / ε _a ) × {(T _O ) −f (T _a )｝ + f (T _a ) ‥‥‥ (2). Here, assuming that ε = ε _a , the equation (2) becomes ｛f
_{(T O) -f (T a} )} + f (T a) next to the object 1 in the true temperature f (T _a) is obtained.

Therefore, the CPU 7 may perform the operation of the above equation as shown in FIG.

That is, in FIG. 4, in the first step ST ₁ , the temperature data (ε / ε _O ) of the subject 1 is read from the buffer memory 16.
× The _{{f (T O) -f (} T a)} + f (T a) CPU7
To the memory of.

In the second step ST ₂ , the true temperature f (T _a ) of the subject in the CAL data 15 is
Take in the memory of U7.

In the third step ST ₃ , the corrected emissivity ε _a and ε _O are fetched from the corrected emissivity setting circuit 23 and the entire screen emissivity setting circuit 42 into the memory of the CPU 7.

[0033] In a fourth step ST ₄ [(ε / ε _O) ×
_{{F (T O) -f (} T a)} + f (T a) ] - f
(T _a ) is subtracted, and in the fifth step ST ₅ , (ε
_O / ε _a ) × [(ε / ε _O ) × ｛f (T _O ) −f
(T _a)}] is the multiplication is performed, in the sixth step ST _{6 [(ε / ε a) × {} f (T O) -f (T a)} ] + f
By adding the CAL data according to (T _a ), the emissivity can be corrected. The emissivity ε _a set near the cross cursor 30 on the CRT screen 24 and the temperature T _O corrected by the corrected emissivity are digital. Displayed as display value.

In the present invention, the multi-point position designation on the screen by the cross cursor 30 is conventionally displayed as A, B, C # near the cross cursor position, and the temperature color displayed on the right end of the screen. Since it was displayed at the position of the separate reference scale 41 as A, B, C #, it took time to find the corresponding temperature position on the screen 24. was even when a plurality of the temperature values of performing the correction by the correction emissivity epsilon _a correction emissivity were respectively set to the position of the cross cursor 30 is digitally displayed temperature color reference scale 41
In this case, it is not necessary to visually match the symbols such as A, B, C and the like with the correction points, and an extremely easy-to-read thermographic apparatus can be obtained.

[0035]

According to the thermographic apparatus of the present invention, even when the subject 1 has an object having a different emissivity, it is not necessary to change the emissivity each time to perform measurement, and the index point such as a cross cursor can be measured. Emissivity correction based on the material difference of the object or the ambient temperature difference can be corrected because the emissivity correction can be performed only by specifying, and the correct temperature distribution of the corrected emissivity point is displayed digitally, so it is very easy to understand the thermography device Is obtained.

[Brief description of the drawings]

FIG. 1 is a system diagram of a thermographic apparatus according to the present invention.

FIG. 2 is an external view of a main body of the thermographic apparatus according to the present invention.

FIG. 3 is an explanatory diagram of a screen display of the display device of the thermographic apparatus according to the present invention.

FIG. 4 is a flowchart of a corrected emissivity calculation of the present invention.

FIG. 5 is an explanatory diagram of a screen of a conventional thermography apparatus.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 subject 3 detection unit 6 whole screen emissivity correction circuit 9 image memory 11 display device 17 subtractor 18 multiplier 19 adder 20 thermography device 23 corrected emissivity setting circuit

Claims (2)

[Claims] 1. A thermography apparatus for displaying a temperature distribution image of an object by correcting the emissivity of the entire screen based on temperature data obtained by detecting infrared energy from the object. A thermographic apparatus characterized by digitally displaying a corrected emissivity temperature value and a set emissivity of the indicated point position in the vicinity of the index indicated point position. 2. The thermographic apparatus according to claim 1, wherein the position of the designated index point is displayed at multiple points.