JPS587529A - Optical temperature measuring method - Google Patents

Abstract

PURPOSE:To make it possible to perform highly accurate temperature measurement, by measuring the afterglow characteristic, with a changing point of the intensity of the emitted light of photoluminescence itself as a reference. CONSTITUTION:A light emitting device 1 generates excited light pulses E. The intensity of the excited light of the pulses E suddenly changes stepwise in the middle. The pulses are irradiated on a phosphorescent and fluorescent body 4 through an optical system 3. The fluorescent body 4 generates the photoluminescence F, and its intensity responses the sudden change of the excited light intensity and changes stepwise. A time point P' of said change corresponds to a time point P of the change of the pulse E. A constant difference in steps in the intensity of the emitted light is formed with said time point P' as a boundary. Said time point P' is imparted to a control circuit 2 through an optical system 5 and a light receiving device 6 and detected. Then the stable intensity of the emitted light Io is obtained. With the decrease in the intensity Io after the stop of the excitation, a time point Q at 90% of the intensity Io and a time point R at 10% are detected. Then with the time point P' as time reference, delay time t1 and attenuation time t2 are obtained, and the afterglow characteristic is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for optical thermostatic adjustment that utilizes the temperature dependence of afterglow 41111 of photovoltaic electronics.

Conventionally, a light pulse is irradiated to a phosphor placed in the temperature atmosphere of the object to be measured to generate photoluminescence in the phosphor, and the afterglow characteristics of wrinkle photoluminescence are measured. For example, a device as shown in FIG. 1 is known as a device for controlling temperature straight pipes. In Figure 1, 1 emitter 1
is the control circuit 2 or the excitation pulse as an electric signal (second
(shown in the figure) generates nine excitation light pulses (not shown) approximating this excitation pulse, and these excitation light pulses and pulses pass through an optical system 3 including lenses, etc. to the phosphor. It is designed to be irradiated at 4. The phosphor 4 is stimulated by an excitation light pulse and generates a photoreceptor C shown at 2111, which is guided to a light receiver lI6 via an optical system 5. At this time, the phosphor phosphor 4 is placed in the warm atmosphere 7 of the heated body and is influenced by it. Therefore, the afterglow characteristic of the photovoltaic device 7th C changes and is electrically converted in the receiver 6. temperature information will be included. The control circuit 2 starts a timer at the rising edge or falling edge of the excitation pulse, and activates the light receiver 6.
The afterglow characteristics (delay time and decay time) of photoluminescence C input from I! are measured, and based on the results, the corresponding I!
I'm looking for degree.

However, in such conventional methods, the afterglow characteristic is measured using the excitation pulse A, which is an electric signal, as a reference. - Optical conversion, and further optical-to-electrical conversion in the light receiver 6 (each has a delay, and these delays add up to cause errors, making it impossible to measure temperature with high precision.

The present invention was made in view of these conventional problems, and aims to provide a highly accurate optical temperature measurement method by measuring the afterglow characteristic of photoluminescence itself.

In order to achieve the above-mentioned object, this invention makes the waveform of the excitation light pulse that irradiates the fluorophore step-like, abruptly changes the excitation light intensity during the excitation, and the emission intensity of photoluminescence changes correspondingly. It is characterized in that the afterglow characteristic of the photoluminescence is measured over time by detecting a change point of the photoluminescence and using this as a time reference point.

The following is a detailed description of the embodiments of this invention based on the accompanying drawings.
2BA. Note that the same parts as in FIG. 1 are designated by the same reference numerals and their explanations will be omitted.

FIGS. 3 and 4 are diagrams showing a first embodiment of the present invention. The configuration of the temperature measuring device used in this example is the first one.
This is the same K as the conventional one explained in the figure. The difference is that the electric signal that drives the light emitting a1 has a waveform that suddenly changes stepwise, and in this embodiment, the waveform is a downward step. Therefore, the light emitter 1 is the fourth
An excitation light pulse E as shown in the figure is generated. That is,
The excitation light intensity suddenly changes stepwise during the excitation.

As a result, the phosphor 4 generates photoluminescence F, and the photoluminescence F responds to the sudden change in the intensity of the excitation light described above, and its intensity changes stepwise. The time point P' when the emission intensity of the photoluminescence F changes corresponds to the time point P when the excitation light pulse E changes (because of the afterglow characteristic (due to the afterglow characteristic, the change time point P' occurs later than the change time point P), and this change time point P' There is a fixed difference in the light emission intensity IRK with the boundary between IRK and IRK.Therefore, in the control circuit 2, this change point P' is detected by a known sampling technique or the like.

Then, it waits until the level of the light emission intensity becomes stable after the change point P', and detects the stable light emitter III. next,
After the excitation has stopped, the emission intensity is measured to gradually decrease from 1 to 1, and the time point Q when the level reaches 90 degrees of I, and the point R when it reaches 10 degrees are detected. do.

From these results, the delay time t1 and the decay time t2 can be easily determined using the change point P' as a time reference.

Like Jin, the afterglow characteristics of photoluminescence are measured based on the change point of the emission intensity of the photoluminescence itself (therefore, there are no error factors as in conventional methods, and highly accurate temperature measurement is possible.In particular, Since the light-to-electricity conversion characteristics of the light emitter 1 and the light receiver 6 are unrelated, the measurement may be possible even with a light emitter or a light receiver that has a slow response. FIG.

In this embodiment, since the step-like waveform of the excitation light pulse G is upper stepwise, the light emission intensity is high in the portion related to the measurement of photoluminescence H. Therefore, temperature measurement with high S/N can be performed.

Furthermore, FIG. 6 is a diagram showing another example of the configuration of the warm honey meter. In this configuration example, the reciprocating optical system is configured with one light 7 eyeper 10, and by taking advantage of the fact that the wavelengths of the excitation light pulse E (tdG) and the photoluminescence F (straddle ■) are different, both are separated by a beam splitter 11.

Note that even if the excitation light is high-frequency modulated light,
As long as the high frequency is a signal with a sufficiently short wavelength compared to the afterglow time of the phosphor phosphor, the present invention can be applied in the same manner as in the embodiments described above.

As described in detail above, according to the present invention.

The intensity of the excitation light is suddenly changed during the excitation, and the afterglow characteristics are measured using the time point at which the emitted light intensity of the responding photoreceptor itself changes as a reference, making it possible to measure temperature with high precision.

[Brief explanation of drawings]

1 and 2 are a schematic configuration diagram of a temperature measurement device and a photoluminescence afterglow characteristic diagram explaining a conventional optical temperature measurement method, and FIG. 3 is a schematic configuration diagram of a temperature measurement device according to the present invention, FIG. 4 is an explanatory diagram of the operation of the first embodiment of the present invention, FIG. 5 is an explanatory diagram of the operation of the second embodiment of the invention, and FIG. It is a schematic configuration diagram showing another configuration example. 4... Phosphorescent material g, G--Excitation light pulse F, H--... Photoluminescence P'...
・・・・Change point of luminescence intensity t, ta・・・・Afterglow delay time t!・・・・・・Afterglow decay time patent applicant
・Tateishi Electric Co., Ltd. Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] (1) When a large number of phosphors placed close to the body to be measured are optically stimulated with an excitation light pulse, the afterglow 4I characteristic of the photoki energy emitted by the phosphor phosphor is temperature dependent. In one method, the intensity of the excitation light is abruptly changed stepwise during the excitation by the excitation light pulse, and in response to the sudden change in intensity of the excitation light, the photoluminescence is Netsense luminescence strength 1! Detect the time point at which the change occurs, and use the detected time point as a reference to determine the value of the current value after the excitation stops.
An optical temperature measurement method that is characterized by keeping the afterglow bone quality of the water constant over time.