JPS62263425A - Thermography apparatus - Google Patents

Abstract

PURPOSE:To obtain the title apparatus capable of easily judging the size of an object, by displaying the information of the length relating to an infrared image on the same picture as the infrared image. CONSTITUTION:The image of an infrared ray detector 1 is formed on an object as a spot by moving a focus matching lens 2 by a drive mechanism 3. With the secondary scanning of said spot by a scanner 4, the infrared image of an object is displayed on a display part 11 on the basis of the infrared image signal obtained from the detector 1. The position data of the lens 2 is obtained by the digital potentiometer 12 mounted on the mechanism 3 and, further, the data of the distance between a thermography apparatus and the object is obtained from said position data by a distance converting circuit 13. The scanner 4 has horizontal and vertical scanning mirrors and the positional change of either one of them is calculated by a position detector 14 and the data relating to the angle of a visual field is obtained from the signal of said detector 14 by a visual field angle converting circuit 17 through an amplitude detection circuit 15. The information of the length relating to the object is displayed on the same picture as the infrared image on the basis of said two data.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application 1] The present invention relates to a thermography apparatus that can easily determine the length of a subject in an infrared image displayed on a screen.

[Prior Art] A thermography device scans a field of view two-dimensionally and detects infrared rays emitted from each point within the field of view.

The obtained infrared image signal is introduced into a display device directly or via a storage means to display an infrared image.

[Problems to be solved by the invention] When it is desired to determine the size of an object present in this infrared image, conventionally, the size of an object existing in the infrared image is measured by actually applying a scale to the object. , what if you can't get close to the target? A11 constant is extremely difficult.

The present invention has been made in view of this point, and provides a thermography device that can easily determine the size of an object by displaying length information regarding an infrared image on the same screen as the infrared image. It is intended to.

[Means for Solving the Problems] To achieve this objective, the present invention provides an infrared detector, an imaging means for forming an image of the infrared detector on a subject, and an infrared detector image forming means for forming an image of the infrared detector on a subject. A thermograph comprising: an optical scanning means for two-dimensionally scanning a subject; and a display device displaying an infrared image of the subject based on an infrared image signal obtained from an infrared detector based on the two-dimensional scanning. The apparatus includes means for outputting distance data to the subject based on position information of the imaging means, and means for generating information regarding a horizontal or vertical field of view regarding an infrared image displayed on a display device, and the field of view information is provided. The present invention is characterized in that length information regarding the subject in the infrared image is displayed on the same screen as the infrared image based on the distance data.

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

[Example] FIG. 1 is a schematic diagram showing an example of a thermography apparatus implementing the present invention. In the figure, 1 is an infrared detector, 2 is a focusing lens for forming an image of the infrared detector 1 as a spot on the subject, 3 is a drive mechanism for moving the focusing lens 2, and 4 is an infrared detector. This is a scanner for two-dimensional scanning of an image spot. The infrared image signal obtained from the infrared detector 1 during this two-dimensional scanning is transmitted to the amplifier 5. The image is sent to the image memory 8 via the processing circuit 6 and the A/D converter 7 and stored therein. The infrared video signal stored in the memory is read out at high speed by the readout circuit 9 and sent to the display device mi via the TV signal conversion circuit 10.
Sent to i.

Position data of the focusing lens is obtained from a digital potentiometer 12 attached to the driving machine Mli3, and this position data is converted by a distance conversion circuit 13 into data representing the distance between the thermography apparatus and the subject.

The scanner 4 has horizontal and vertical scanning mirrors, and a position detector 14 is provided to detect a change in the position of either one of the scanning mirrors. As the position detector 14, for example, a type that detects the movement of a magnet attached to a scanning mirror using a pickup or coil arranged around the scanning mirror is used. The amplitude of the signal indicating the movement of the scanning mirror obtained from the position detector 14 is determined by the amplitude detection circuit 15;
The obtained amplitude signal is sent to the viewing angle conversion circuit 17 via the A-D converter 16. 18 is data regarding the viewing angle obtained from the conversion circuit 172 and the distance conversion circuit 13;
An arithmetic circuit 19 is a character and graphic signal generation circuit that generates a character signal and/or a graphic signal based on the result of the calculation and sends it to the TV signal conversion circuit 10.

In the above configuration, by setting the lens 2 at an appropriate position using the drive mechanism 3, the image of the infrared detector 1 can be formed as a spot on the target object. This focusing may be performed manually by an operator or using a known automatic focusing mechanism.

The detector image spot S thus formed on the subject is scanned by the scanner 4 as shown in FIG. 2 over the subject. Accordingly, an infrared image signal is obtained from the detector 1, and when this infrared image signal is stored in the memory 8, read out and sent to the display device 11, the infrared az of the rask-scanned area is displayed on the screen of the display device, for example. Third
The screen is displayed as shown in Figure (a).

As can be seen from Figure 2, the length on the subject corresponding to the width of the displayed infrared image is calculated using the following formula, where α is the horizontal viewing angle and L is the distance between the scanning origin O and the subject. It is expressed as

Q=2L tan(α/2) (1)
By the way, since the position of the lens 2 corresponds one-to-one to the distance between the subject and the thermography device, if a lens position-distance conversion table is stored in the conversion circuit 13 in advance, the driving voltage can be reduced.
JI! By sending the position data of the lens 2 from the potentiometer 12 attached to the structure 3 to the conversion circuit 13,
Data on the distance between the subject and the device can be obtained.

On the other hand, since the amplitude of the vibration of the horizontal scanning mirror in the scanner 4 has a one-to-one correspondence with the horizontal viewing angle α, if an amplitude-viewing angle conversion table is stored in the modification circuit 17 in advance, the amplitude detection circuit By sending the data regarding the amplitude of the horizontal scanning mirror obtained from 15 to the conversion U path 17, data on the viewing angle α can be obtained.

The arithmetic circuit 18 uses the data L obtained in this way.
and α, calculate the length on the subject corresponding to the width of the infrared B image, and send this value to the character/figure signal generation circuit 19. Character/figure signal generation circuit 1
9 generates a character signal to display this value, and T
In order to send it to the V signal conversion circuit 10, the screen of the display device shows:
As shown in FIG. 3(a), the value 2 is displayed numerically on the same screen as the infrared image. This number indicates the width of the infrared image, that is, how many meters the width of the subject within the horizontal viewing angle corresponds to. Based on this number, the operator can determine the approximate length or size of the subject or part of the subject. can be judged.

In addition, in Fig. 3(a), the length corresponding to the width of the infrared image is displayed, but as shown in Fig. 3(b), a fixed marker M having a length of 1/N of the width of the infrared image is displayed. It may be displayed superimposed on the infrared image, and the number of meters this fixed marker corresponds to on the subject may be displayed numerically. At this time, the numerical value to be displayed is inclusive/N, which can be obtained by the arithmetic circuit 18 and sent to the character/figure signal generation circuit 19.

FIG. 3(C) shows yet another display method. In this example,
The length of the marker is variable, and markers having a length corresponding to a predetermined standard length a (for example, 1 meter) are displayed in an overlapping manner in the infrared tafII. In this case, the arithmetic circuit 18 calculates N=9, /a, and the character/figure signal generation circuit 19 generates a figure signal for displaying a marker with a length of 1/N of the width of the infrared image. You should do it.

Note that if N is smaller than 1, the length of the marker will exceed the width of the infrared image, so in such a case, the value of a should be smaller than 2 so that N is always greater than or equal to 1. is preferred. Also, if N becomes too large (for example, 10 or more), the marker becomes short and its length cannot be accurately recognized, so in such a case, increase the value of a to prevent N from becoming too large. is preferred. In this way, the arithmetic circuit 18 switches a appropriately.
This can be done automatically according to the value of N.

In the above embodiment, information regarding the horizontal viewing angle α was obtained by actually detecting the vibration of the scanning mirror, but this is not necessarily necessary.

For example, in a thermography device with a fixed horizontal viewing angle, it is sufficient to use a constant α, but in a thermography device where the horizontal viewing angle is variable over multiple stages using a zoom function, or in a thermography device that scans using a rotating polygon mirror, the viewing angle It is sufficient to select the horizontal viewing angle based on command information specifying or selecting the horizontal viewing angle, and it is not necessarily necessary to actually measure the viewing angle.

In addition, in the above embodiment, the operation q is performed in the arithmetic circuit each time, but if the operation is performed in advance, the result of the operation is held as a table, and the result is read from the table according to L and α, the operation can be performed. n circuits are not required.

Furthermore, although the above embodiment focused on the horizontal viewing angle, the same applies when focusing on the vertical viewing angle.

[Effects] As detailed above (according to the present invention, the thermography apparatus can easily determine the size of a subject by displaying length information regarding an infrared image on the same screen as the infrared image). is realized.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an example of a thermography apparatus implementing the present invention, FIG. 2 is a diagram for explaining rask scanning,
FIG. 3 is a diagram showing an example of display on the screen of the display device. 1: Infrared detector 2: Focusing lens 4: Scanner 8: Image memory 11: Display device 12: Potentiometer 13: Distance conversion 0 path 14: Position detector 17: Viewing angle conversion circuit 18: Arithmetic circuit 19: Character Graphic signal generation circuit

Claims (1)

[Claims] (1) An infrared detector, an imaging means for forming an image of the infrared detector on a subject, and an optical scanning means for two-dimensionally scanning the infrared detector image on the subject. ,
A thermography apparatus comprising a display device that displays an infrared image of a subject based on an infrared image signal obtained from an infrared detector based on the two-dimensional scanning, wherein distance data to the subject is displayed based on position information of the imaging means. and means for generating information regarding a horizontal or vertical field of view regarding an infrared image displayed on a display device, and generating length information regarding a subject in the infrared image based on the field of view information and the distance data. A thermography device characterized by displaying an infrared image on the same screen.