JP2000131149A - Infrared temperature measuring apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make an infrared detector usable as a calibration reference heat source for the temp. measurement by providing a means for controlling the temp. for constant temp. and a means for opening/closing a mirror-surface finished shutter and picking up the reflected image of the infrared detector. SOLUTION: By having a shutter 4 slide along a plane at right angles to the incident optical axis of an infrared ray radiated by an object to be measured, the shutter is opened/closed. When the shutter 4 is closed, an infrared detector 2 picks up the image of the detector 2 itself which is reflected on the shutter 4. A correcting means for obtaining a correct temp. value accurately controls the temp. of the detector 2 for a constant temp., instead of a reference heat source 3. Thus, without using an exclusive reference heat source, the temp. can be measured similar to the conventional apparatus. Although the shutter 4 is shown with one sheet, but a plurality of shutters may be used. Thus the apparatus can be downsized and a more accurate temp. measurement can be made by working the shutter 4 into a recessed shape.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an infrared temperature measurement for measuring the temperature of an object to be measured by comparing the infrared radiation level of a reference heat source whose true temperature is known in advance with the amount of infrared radiation of the object to be measured. Related to the device.

[0002]

2. Description of the Related Art FIG. 6 shows an example of a conventional infrared temperature measuring device of this kind. In the drawing, reference numeral 1 denotes an infrared lens that collects infrared rays emitted from an object to be measured, and 2 denotes an infrared detector that converts the infrared rays collected by the infrared lens 1 into an electric signal. For example, in a two-dimensional infrared detector, , 320 infrared detectors horizontally and 240 infrared detectors vertically are two-dimensionally arranged to constitute one screen. Reference numeral 3 denotes a reference heat source for obtaining a temperature value from an electric signal level output from the infrared detector 2. Reference numeral 4 denotes a shield that does not receive infrared rays emitted from the object to be measured that pass through the infrared lens 1 and is used instead. A shutter for reflecting and receiving infrared rays emitted from the reference heat source 3, and has a mirror-finished side facing the infrared detector 2. Reference numeral 5 denotes an infrared detector 2 which selects one of the infrared light emitted from the object to be measured and the infrared light emitted from the reference heat source 3.
, A shutter drive unit for driving the shutter 4, a temperature control unit 6 for accurately controlling the reference heat source 3 at a constant temperature, and a temperature control unit 7 for controlling the temperature of the reference heat source 3 controlled by the temperature control unit 6. A temperature monitor 8 to be monitored is a video signal processing unit for converting an electric signal output from the infrared detector 2 into digital video data. According to the above-described example, 320 horizontal pixels and 240 vertical pixels correspond to one screen. Output digital video data. Reference numeral 9 denotes a temperature value conversion unit for converting digital video data output from the video signal processing unit 8 into temperature value data based on a predetermined calculation formula. Output temperature value data. Reference numeral 10 denotes a processor, which determines the output of the temperature monitor 7 to control the temperature control unit 6 and decodes a control signal from the operation unit 12 in order to maintain the temperature of the infrared detector 2 at a constant temperature. It outputs a shutter drive control signal to the shutter drive unit 5 and sends measured temperature data to the display processing unit 11. 1
Reference numeral 1 denotes a display processing unit, which combines digital video data output from the video signal processing unit 8 and measured temperature values output from the temperature value conversion unit 9 on one screen and displays them on a normal television monitor. Reference numeral 12 denotes an operation unit for designating the position of the measured object on the display image of the display processing unit 11 and instructing the shutter 4 to be driven.

Next, an operation example will be described. Typically,
In this type of infrared temperature measurement device, the shutter 4 can be opened and closed by operating the shutter drive unit 5 by the operation unit 12, and it is possible to switch between imaging the object to be measured and the reference heat source 3. I have. When imaging an object to be measured, the shutter 4 is positioned so as not to block the optical path of the incident infrared light as indicated by the dotted line in the figure, and the infrared light emitted from the object to be measured is collected by the infrared lens 1. It reaches the infrared detector 2, where it is converted into an electrical signal. The electric signal is subjected to video signal processing similar to that of a normal television camera in the video signal processing unit 8, for example, 30 seconds per second.
The data is output to the display processing unit 11 as digital image data of a screen. Thereby, the display processor 11 can obtain an infrared image of the measured object. In addition, the digital image data is also output to the temperature value converter 9 at the same time, where the infrared radiation amount of the measured object and its temperature are uniquely associated with each other based on a predetermined calculation formula according to a physical principle. Convert the amount of infrared radiation to a temperature value. Processor 10
Selects a corresponding value from the temperature value data output from the temperature value conversion unit 9 based on the position designation information of the measured object transmitted from the operation unit 12, and displays a numerical value indicating the temperature on the display processing unit 11. Display as Here, the above-mentioned predetermined formula only converts the amount of infrared radiation into a temperature value, and in an application to an actual infrared temperature measuring device, the infrared detector 2 of the infrared detector 2 is changed due to a change in a temperature environment in which the device is used. There is a problem that the output electric signal level cannot be uniquely associated with the amount of infrared radiation emitted by the measured object. Therefore, in order to obtain a correct temperature value, a means for correcting this fluctuation factor is required. As a typical method for this correction, a method using the reference heat source 3 is used. The temperature of the reference heat source 3 is accurately controlled to a constant temperature, and the temperature is obtained when the infrared detector 2 captures an image of the reference heat source 3. The temperature of the measured object is measured from the difference between the measured electric signal level and the electric signal level obtained when the measured object is imaged. That is,
The fluctuation of the output level of the infrared detector 2 due to the temperature environment is as follows.
Since this acts as an offset with respect to the true temperature, if the difference is canceled and the above-mentioned predetermined formula is applied, a certain degree of accurate temperature measurement can be performed. To control the temperature of the reference heat source 3, a control loop is formed by the processor 10, the temperature monitor 7, and the temperature control unit 6, and control by heating or cooling is performed so that the temperature of the reference heat source 3 is always constant. When the shutter 4 is moved to the position shown by the solid line in the figure by operating the shutter drive unit 5 with the operation unit 12 in the state where the reference heat source 3 is kept at a constant temperature in this manner, the optical path of the infrared light emitted from the object to be measured is Is shutter 4
The infrared rays emitted by the reference heat source 3 are imaged by the infrared detector 2 instead. The electric signal obtained by the infrared detector 2 passes through the video signal processing unit 8 and does not pass through the temperature value conversion unit 9 and is converted into digital image data by the processor
Read at 0. Since the read digital image data corresponds to the temperature value of the reference heat source 3, this value is stored in the temperature value converter 9 and the digital image obtained when the shutter 4 is returned to the position shown by the dotted line. By applying the result of the difference with the data to the above-mentioned predetermined formula and outputting the temperature value from the temperature value converter 9, the relative temperature with respect to the reference heat source 3 can be obtained. The display processing unit 11 displays the sum of the control temperature of the reference heat source 3 and the obtained relative temperature.

[0004]

As described above, the conventional infrared temperature measuring apparatus requires a dedicated reference heat source to measure a correct temperature, and therefore has a problem that the apparatus itself tends to be large. there were.

The present invention has been made to solve the above-described problems, and has as its object to provide an infrared temperature measuring apparatus capable of measuring a correct temperature without having a dedicated reference heat source.

[0006]

According to a first aspect of the present invention, there is provided an infrared temperature measuring device for controlling a temperature of an infrared detector to a constant temperature, and opening and closing a shutter having a mirror-finished side facing the infrared detector. The shutter is reflected by the infrared detector itself to take an image, so that the infrared detector is used as a calibration reference heat source for temperature measurement.

Further, an infrared temperature measuring apparatus according to a second aspect of the present invention comprises:
In the first invention, as the shutter driving means, a shutter driving means for sliding the shutter along a plane perpendicular to an incident optical axis of infrared light emitted from the object to be measured is used.

[0008] An infrared temperature measuring apparatus according to a third aspect of the present invention comprises:
In the invention, the shutter driving means includes a shutter driving means for rotating the shutter about an axis perpendicular to an incident optical axis of infrared rays emitted from the object to be measured.

A fourth aspect of the present invention is an infrared temperature measuring apparatus,
In the first invention, as the shutter driving means, a shutter driving means for rotating the shutter about an axis which is horizontal to an incident optical axis of infrared rays emitted from the object to be measured is used.

A fifth aspect of the present invention is an infrared temperature measuring apparatus,
According to the fourth aspect of the invention, a shutter is used as the shutter, in which a side facing the infrared detector is processed into a concave mirror shape, and an image of the infrared detector itself is focused on a specific pixel area of the infrared detector. It was what was.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 is an example showing Embodiment 1 of the present invention. In the figure, 1, 2,
Reference numerals 4 to 11 perform the same functions as those of the conventional device. In the example of the present invention, the point at which the shutter 4 slides along a plane perpendicular to the incident optical axis of the infrared light emitted from the object to be measured to open and close, the temperature control unit 6 and the temperature monitor 7 include the infrared detector 2 Is different from the conventional device.

Next, the operation will be described. In the infrared temperature measuring apparatus of the present invention configured as described above, the opening and closing of the shutter 4 is performed by sliding the shutter 4 along a plane perpendicular to the incident optical axis of the infrared light emitted from the measured object. When the shutter 4 is closed, the infrared detector 2 is reflected by the infrared detector 2
It captures its own image. The means for performing the correction for obtaining the correct temperature value controls the temperature of the infrared detector 2 accurately and to a constant temperature in place of the reference heat source 3 in the above-described conventional apparatus. Except for these structural differences, the operations of the video signal processing flow, the temperature value calculation method, the temperature control method, the image display operation, the control method from the operation unit, and the like are the same as those of the conventional device. As described above, the temperature can be measured in the same manner as in the conventional apparatus without using the dedicated reference heat source. In the figure, shutter 4 is 1
Although it is shown by a sheet, it may be developed into a plurality of sheets.

Embodiment 2 FIG. FIG. 2 is an example showing Embodiment 2 of the present invention. In the figure, 1 to 11 perform the same function as in the first embodiment, but in the example of the present invention, the shutter 4 rotates around an axis perpendicular to the incident optical axis of the infrared light emitted from the measured object. This embodiment differs from the first embodiment in that it opens and closes.

Next, the operation will be described. In the infrared temperature measuring apparatus of the present invention configured as described above, the opening and closing of the shutter 4 is performed by opening and closing by rotating around an axis perpendicular to the incident optical axis of the infrared light emitted from the measured object. When the shutter 4 is closed, the infrared detector 2 captures the image of the infrared detector 2 reflected on the shutter 4 itself. Except for the configuration of the shutter 4, the operation and control method of the other parts are the same as those of the first embodiment.
Is the same as In the figure, the shutter 4 is shown as a single shutter, but it may be developed into a plurality of shutters as shown in FIG.

Embodiment 3 FIG. 4 is an example showing Embodiment 3 of the present invention. In the figure, 1 to 11 perform the same function as the first and second embodiments, but in the example of the present invention, the shutter 4 is centered on an axis that is horizontal to the incident optical axis of the infrared light emitted from the measured object. It differs from the first and second embodiments in that it rotates and opens and closes.

Next, the operation will be described. In the infrared temperature measuring apparatus of the present invention configured as described above, the opening and closing of the shutter 4 is performed by rotating and opening and closing the shutter 4 about an axis that is horizontal to the incident optical axis of the infrared light emitted from the measured object. When the shutter 4 is closed, the infrared detector 2 captures an image of the infrared detector 2 reflected on the shutter 4 itself. Except for the configuration of the shutter 4, the operation and control method of the other parts are the same as in the first and second embodiments. In the figure, the shutter 4 is shown as two shutters 4a and 4b, but may be developed to three or more shutters. As an example,
There is a method of arranging a large number of shutter groups and their rotation axes so as to surround the infrared lens 1 like an aperture mechanism in a general camera lens.

Embodiment 4 FIG. 5 is an example showing Embodiment 4 of the present invention. In the figure, 1 to 11 perform the same functions as the first to third embodiments, but in the example of the present invention, the side of the shutter 4 facing the infrared detector 2 is:
The point that is processed into a concave mirror shape and that the entire amount of infrared rays emitted from the central pixel of the infrared detector 2 is reflected on the shutter 4 without being scattered and is collected again on the central pixel of the infrared detector 2 as described above. Different from modes 1 to 3.

Next, the operation will be described. In the infrared temperature measuring device of the present invention configured as described above, the opening and closing of the shutter 4 is performed by sliding or rotating as in the first to third embodiments. The detector 2 captures an image of the infrared detector 2 reflected on the shutter 4 itself. Except for the configuration of the shutter 4, the operation and control method of the other parts are the same as in the first to third embodiments. The present invention is the same as the first to third embodiments, except that the infrared detector 2
When the infrared rays emitted by the infrared ray are reflected by the shutter 4, the infrared rays are scattered and the total radiant energy cannot be captured by the infrared detector 2. In order to reduce the complexity of the temperature value conversion unit 9 requiring a correction process in accordance with the above. As this method, the side of the shutter 4 facing the infrared detector 2 is processed into a concave mirror shape so that the total radiation energy of the infrared detector 2 can be captured by the infrared detector 2. In addition,
Actually, for example, horizontal 320 which constitutes the infrared detector 2
Since it is structurally difficult to catch the energy radiated by each pixel without scattering for all the pixels, 240 pixels vertically, the pixel radiates, for example, only to the central pixel of the infrared detector 2 The energy is captured without scattering. As a result, more accurate temperature measurement can be performed without requiring complicated correction processing.

[0019]

As described above, according to the present invention, it is possible to measure a correct temperature with a dedicated reference heat source. Thereby, the size of the device can be reduced. Further, if the shutter shape is processed into a concave shape, more accurate temperature measurement can be performed.

[Brief description of the drawings]

FIG. 1 is a diagram showing a first embodiment of the present invention.

FIG. 2 is a diagram showing a second embodiment of the present invention.

FIG. 3 is a diagram showing a third embodiment of the present invention.

FIG. 4 is a diagram showing a fourth embodiment of the present invention.

FIG. 5 is a diagram showing a fifth embodiment of the present invention.

FIG. 6 is a diagram showing a conventional infrared temperature measuring device.

[Explanation of symbols]

1 infrared lens, 2 infrared detector, 3 reference heat source,
4 shutters, 4a shutters, 4b shutters,
4c shutter, 5 shutter drive section, 6 temperature control section, 7 temperature monitor, 8 video signal processing section, 9 temperature conversion section, 10 processor, 11 display processing section.

Claims (5)

[Claims] 1. An infrared temperature measuring device for measuring the temperature of an object to be measured by comparing the amount of infrared radiation of a reference heat source whose true temperature is known in advance with the amount of infrared radiation of an object to be measured. An infrared detector that converts the electric signal into an electric signal, and shields the infrared detector so as not to receive the infrared light emitted by the object to be measured, and reflects and receives the infrared light emitted by the infrared detector itself. A shutter having a mirror-finished side facing the infrared detector, shutter driving means for opening and closing the shutter, means for maintaining the infrared detector at a constant temperature, and a temperature sensor for monitoring the temperature of the infrared detector A means for calculating a temperature value based on a predetermined formula from the output signal of the infrared detector and the temperature sensor, and a calibration base for measuring the temperature of the object to be measured. An infrared temperature measuring device, wherein an image of the infrared detector itself obtained by reflection on the shutter is used as the quasi-heat source, and the infrared detector is maintained at a constant temperature. 2. The shutter driving unit according to claim 1, wherein the shutter driving unit is a shutter driving unit that slides the shutter along a plane perpendicular to an incident optical axis of infrared light emitted from the measured object. Infrared temperature measurement device. 3. The shutter driving unit according to claim 1, wherein the shutter driving unit is a shutter driving unit that rotates the shutter about an axis perpendicular to an incident optical axis of infrared light emitted from the object to be measured. Infrared temperature measurement device. 4. The shutter driving unit according to claim 1, wherein the shutter driving unit is a shutter driving unit that rotates the shutter about an axis that is horizontal to an incident optical axis of infrared light emitted from the object to be measured. Infrared temperature measurement device. 5. The shutter, wherein a side facing the infrared detector is processed into a concave mirror shape, and an image of the infrared detector itself is focused on a specific pixel area of the infrared detector. The infrared temperature measuring device according to any one of claims 1 to 4, wherein