JPH03118428A - Infrared-ray thermometer - Google Patents

Abstract

PURPOSE:To measure the temperature of a body accurately by computing the optical loss rate of a probe based on the amount of emitted light from a light emitting means, the reflectivity of a reference surface and the amount of light received by a light receiving means when the temperature is not measured, and correcting the amount of infrared rays when the temperature is measured. CONSTITUTION:When temperature is not measured, a reference surface is covered with a hood based on the signal from a reference-surface driving device 83. An optical fiber 5 is made to face with an optical fiber 5A by means of an optical switch 21. Under this state, the light emitted from a lamp 23 through a contamination detecting switch 40 is projected on the reference surface through a half mirror 22, the fiber 5A, the switch 21, the fiber 5 and a probe. Then, the light reflected from the reference surface is propagated through the original path and detected with a detector 24 through the mirror 22. In an optical-loss operating part 25, the correcting amount corresponding to the amount of the optical loss is computed and stored in a temperature operating part 27. When the temperature is measured, the hood is opened based on the signal from the device 83. The infrared rays are detected with an infrared-ray detector 26 through the fiber 5, the switch 21 and an optical fiber 5B. The result is corrected in correspondence with the amount of correction in the operating part 27, and a correct temperature is measured.

Description

[Detailed Description of the Invention] [Summary] This invention relates to an infrared thermometer that measures temperature by detecting the amount of infrared rays emitted by an object.
The aim is to provide an infrared thermometer that can accurately measure the temperature of an object by detecting the degree of contamination of the probe.The infrared rays emitted by the object are focused through a hood, and the amount of infrared rays collected is used to determine the temperature of the object. In an infrared thermometer that measures temperature with a temperature measuring device, a reference surface with a constant light reflectance provided at the opening of the hood, and a reference surface drive that moves the reference surface to open the hood during temperature measurement. a half mirror provided in an infrared path in the temperature measuring device;
a light emitting means provided on the input side of the half mirror; and a light receiving means provided on the output side of the half mirror;
a light loss calculating means for calculating a light loss rate based on the amount of light emitted from the light emitting means, the amount of light received from the light receiving means, and the reflectance of the reference surface when temperature is not being measured; and light from the light loss calculating means when measuring temperature. and infrared ray amount correction means for correcting the amount of infrared rays input to the temperature measurement based on the loss rate.

(Industrial Application Field) The present invention relates to an infrared thermometer that measures temperature by detecting the amount of infrared rays emitted by an object.

The amount of infrared radiation emitted by an object increases as its temperature increases. Therefore, by measuring the amount of infrared radiation emitted by an object, the temperature of the object can be determined. This infrared temperature measurement method is an excellent temperature measurement method because it is a non-contact method, does not contaminate the measurement surface, and does not cause temperature changes due to contact.

Conventionally, in a vacuum thin film formation process, that is, a process in which a film is formed on a substrate using sputtering in a vacuum, a high degree of cleanliness of the film forming surface is required in order to maintain uniform properties of the film. For this reason, infrared thermometers that measure temperature in a non-contact manner are extremely important for temperature measurement during processes. Furthermore, this non-contact method has the advantage of being applicable to the temperature characteristics of mass production processes that handle many substrates.

However, as I used this infrared thermometer,
If the path that collects infrared rays and sends them to the measurement unit is dirty, temperature measurement errors will occur, so an infrared thermometer that can accurately measure the temperature of an object even if the infrared propagation path is dirty is desired. .

[Conventional technology]

Figure 6 shows the configuration of a conventional infrared thermometer.
An infrared detection probe 10 is placed inside the vacuum apparatus 50, and infrared rays from a disk D on which a thin film is formed within the vacuum apparatus 50 are collected by a hood 1 provided at the tip thereof. The optical path of the focused infrared light is bent at right angles by the reflecting mirror 2, and the infrared light is taken out of the vacuum device 50 through an optical fiber (described later) provided inside the cylinder of the probe 10, and outside the vacuum device 50, it is transmitted through an optical fiber cable 30. The obtained amount of infrared rays is sent to the temperature measuring device 20, where the amount of infrared rays is measured and the temperature of the disk D is displayed. A flange portion 31 for fixing is an optical connector for connecting the optical fiber cable 30 to the temperature measuring device 20.

FIG. 7 is a cross-sectional view of the probe 10 of FIG.

The probe 10 includes a cylindrical main body 11, a sleeve 12 for holding an optical fiber inserted into the main body 11, and a main body 1.
It is equipped with a cap 13 attached to the front surface of 1, and an infrared introduction tube 14 protruding from this cap 13,
The hood 1 is connected to the tip of the infrared introduction tube 14 via the reflector 2.
is installed. In addition, the cap 13 and the main body 11
A transmission window 3 made of sapphire material or the like is provided between the transmission window 3 and a condenser lens 4 made of sapphire or the like on the downstream side of the transmission window 3. is provided. 5a is an optical fiber cover, 6 is an O-ring, and 7 is a vacuum bellows.

The infrared rays emitted from the disk D enter the probe 10 through the hood 1, the propagation path of which is bent by 90 degrees by the reflector 2, the infrared rays are transmitted through the infrared introducing gap 14, pass through the transmission window 3, and are reflected by the condenser lens 4. The light is focused and input into the optical fiber 5.

Thereafter, the infrared rays propagate within the optical fiber 5.

FIG. 8 shows details of section A in FIG. 6.

In the figure, 51 indicates the outer wall of the vacuum device 50,
A flange 52 is attached to this outer wall 51 in an airtight manner. A sleeve 53 is attached to this flange 52 in an airtight manner.
An optical fiber 5 passes through it. On the atmospheric side outside the vacuum device 50, the optical fiber 5 is covered with an optical fiber cover 55, which is further covered with a cover coating 56, and the optical fiber cable 30 shown in FIG. It is a general term for

[Problem to be solved by the invention]

However, the conventional infrared temperature monitor configured as described above only collects infrared rays from the measurement surface and transmits them to the measuring instrument through an optical fiber, which can contaminate the probe 10 and reduce the amount of infrared rays detected. Then, there is a problem that the measured value becomes inaccurate. That is, when measuring the temperature during the formation of a vacuum thin film, the amount of infrared rays detected decreases due to the film adhesion reducing the reflectance of the reflecting mirror 2 or the transmission window 3 becoming cloudy, and the measured temperature value decreases. was likely to become uncertain. Furthermore, the hood 1 of the probe 10 is connected to the vacuum device 50.
Since the inside of the detector was always open, the detector was easily contaminated by membrane adhesion.

The purpose of the present invention is to solve the problems with the conventional infrared thermometers, to prevent contamination of the probe in a vacuum device, and to accurately measure the temperature of an object by detecting the degree of contamination of the probe. Our objective is to provide an infrared thermometer that is suitable for

[Means to solve the problem]

A diagram of the principle of the infrared thermometer of the present invention that achieves the above object is shown in FIG. The infrared thermometer shown in FIG. 1 collects infrared rays emitted by an object through a hood 1, and measures the temperature of the object from the amount of the collected infrared rays using a temperature measuring device 20. A known reference surface 8 is provided at the opening of the hood 1, and this reference surface 8 is moved by a reference surface driving device 80 to open the hood 1 during temperature measurement. Further, a half mirror 22 is provided in the infrared passage within the temperature measuring device 20,
A light emitting means 23 is provided on the input side of the half mirror 22, and a light receiving means 24 is provided on the output side. The light loss calculating means 60 calculates a light loss rate based on the amount of light emitted from the light emitting means 23, the amount of light received from the light receiving means 24, and the reflectance of the reference surface 8 when the temperature is not measured, and the infrared light amount correcting means 7
0 corrects the amount of infrared rays input to the temperature measurement 20 based on the light loss rate from the light loss calculation means 60 during temperature measurement.

[Effect]

In the infrared thermometer of the present invention, when not measuring temperature, the hood 1
Since the reference surface 8 covers the opening of the hood, dirt will
Difficult to get inside. In addition, when the temperature is not measured, the light emitting means 23
inputs light into the half mirror 22, this light passes through the optical fiber 5, is reflected by the reference surface 8, passes through the optical fiber 5 again, and reaches the light receiving means 24 from the half mirror 22. Therefore, the light loss rate in the probe 10 can be determined from the relationship between the amount of light emitted from the light emitting means 23, the reflectance of the reference surface 8, and the amount of light received by the light receiving means 24, and this light loss rate can be used to determine the light loss rate when measuring temperature. By correcting the amount of infrared radiation, the correct amount of infrared radiation from the object can be obtained.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 2 shows the configuration of a probe section of an embodiment of an infrared thermometer according to the present invention, which is arranged inside a vacuum device 50 like a conventional infrared thermometer. Therefore, in this embodiment, components that are the same as those of the prior art will be described with the same reference numerals.

The configuration of the probe 10 in this embodiment is the same as that of the conventional one, and includes a sleeve 12 for holding an optical fiber inserted into a cylindrical body 11, a cap 13 attached to the front surface of the body 11, and a protrusion on this cap 13. There is an infrared introduction tube 14 provided, and a hood 1 is attached to the tip of the infrared introduction tube 14 via a reflecting mirror 2. Further, there is a transmission window 3 made of sapphire material or the like between the cap 13 and the main body 11, and on the downstream side of this transmission window 3 there is a condenser lens 4 also made of sapphire or the like. After that there is an optical fiber 5. 5a is an optical fiber cover, 6 is an O-ring, and 7 is a vacuum bellows.

A reference surface 8 having a known light reflectance is provided at the opening of the hood 1 to close the opening, and this reference surface 8 is connected to an air cylinder 82 by a metal rod 81. And disk D
When the temperature is not being measured, the air cylinder 82 is in an extended state, and the reference surface 8 closes the opening of the hood 1.

On the other hand, when measuring the temperature of the disk D, the air cylinder 82 is contracted by a signal from the measuring device 20, which will be described later, and the reference surface 8 is moved from above the hood 1, so that the hood 1 is opened.

In this state, the infrared rays emitted from the disk D enter the probe 10 through the hood 1, the propagation path of which is bent by 90 degrees by the reflector 2, propagates through the infrared introducing gap 14, passes through the transmission window 3, and is concentrated. It is converged by a light lens 4 and connected to an optical fiber 5.
is incident on the Thereafter, the infrared rays propagate within the optical fiber 5.

Note that the aforementioned air cylinder 82 is driven by air pressure and is operated by deformation of the bellows, so there is no problem of air leakage.

FIG. 3 shows the configuration of a temperature measuring device 20 of an infrared thermometer according to an embodiment of the present invention. The temperature measuring device 20 of this embodiment has an optical switch 21 in the input path from the optical fiber 5.
is provided, and the optical fiber 5 is connected to the optical fiber 58 when temperature is being measured and when the temperature is not being measured, and to the optical fiber 5B when the temperature is being measured.

A half mirror is connected to the other end of the optical fiber 5A via a rod lens 22a to improve the coupling between the optical fibers.
A lamp 23 is connected to the input side of this half mirror 22 via a rod lens 22b, and a photodetector 24 is connected to the output side of the half mirror 22 via a rod lens 22c.
is connected. On the other hand, an infrared detector 26 is connected to the other end of the optical fiber 5B. 25 is photodetector 2
4 is an optical loss calculation section connected to the light detection section 24, which calculates the amount of light emitted from the lamp 23 set in advance, the reflectance of the reference surface 8, and the light detection section 24.
Here, the loss rate of light due to dirt on the probe 10 is calculated based on the amount of light received from the probe 10, and a correction signal corresponding to the loss rate is sent to the temperature calculation unit 27. The detected amount of infrared rays from the infrared detector 26 is input to the temperature calculation section 27, and the detected amount of infrared rays is corrected by a correction signal.
The temperature corresponding to the correct amount of infrared rays is output to the temperature display section 28 and the temperature is displayed.

When the temperature is not detected by a switch (not shown) or the like, the air cylinder 82 is extended by the reference surface driving device 83, and the hood 1 of the probe 10 is closed off from the reference surface 8, and at the same time, the air cylinder 82 is extended by the reference surface driving device 83. Upon receiving the signal, the optical switch driving section 29 switches the optical switch 21, and the optical fiber 5 and the optical fiber 5A are connected. on the other hand,
When the temperature detection state is reached, the air cylinder 82 is contracted by the reference plane drive device 83 to open the hood 1 of the probe 10, and at the same time, the light switch drive unit 29 switches the optical switch 21 to connect the optical fiber 5 and the light. Fiber 5B is connected. Further, after the temperature is not detected, when the hood 1 is covered by the reference surface 8 and the optical fiber 5 is connected to the optical fiber 5A, when the dirt detection switch 40 is pressed, the lamp 23 lights up. It looks like this.

An alarm device 90 is provided in the optical loss calculation section 25, and when the light loss rate calculated by the optical loss calculation section 25 is equal to or higher than a predetermined value, the alarm device 90 generates an alarm, and the probe 10 It is also possible to inform the user of the time to replace the transmitting window 3 or the reflecting mirror 2.

FIG. 4 shows an example of the configuration of the optical switch 21 shown in FIG. 3. Inside the optical switch 21, an optical fiber 5B and an optical fiber 5B are fixed side by side, and the optical fiber 5 on the probe 10 side is movably provided on the side opposite to these end faces with a slight distance therebetween. ing. In this embodiment, the optical fiber 5 is attached to the upper end of a piezo element 210 such as a PZT bimorph that is deformed by applying a voltage between two terminals 213 and 214, and when no voltage is applied, the optical fiber 5 The end face of the optical fiber 5 faces the optical fiber 5A. This state is shown in FIG. 5(a) when viewed from the direction of the arrow {circle around (2)}. Reference numerals 211 and 212 in FIGS. 4 and 5 indicate stoppers that limit the movement of the piezo element 210. When a voltage is applied between the two terminals 213 and 214 from the state shown in FIG. 5(a), the piezo element 210 deforms as shown in FIG. 5(b), so that the end surface of the optical fiber 5 faces the optical fiber 5B. become.

Next, the operation of the embodiment configured as described above will be explained separately for when the temperature of the disk D is not measured and when it is measured.

(1) When temperature is not measured At this time, the air cylinder 82 is in an extended state and the reference surface 8 covers the hood 1 due to the signal from the dirty reference surface driving device 83, and the optical switch 21 5 faces the optical fiber 5A. When the dirt detection switch 40 is pressed in this state, the lamp 23 emits light,
The light passes through the half mirror 22, the optical fiber 5A, and the optical switch 21, propagates within the optical fiber 5, and reaches the probe lO.
The light passes through the infrared introducing tube 14, is bent by the reflecting mirror 2, and is reflected by the reference surface 8. The reflected light propagates in the opposite direction along the previous path, is reflected by the half mirror 22, and is received by the detector 24.

Since the amount of light emitted by the lamp 23 and the reflectance of the reference surface 8 are known in advance, the loss of light at the probe 10 can be determined by knowing the amount of light received by the detector. However, in this case, the light from the lamp 23 passes through the probe 10 twice. Therefore, the actual rate of decrease in sensitivity due to optical loss in the optical probe 10 can be determined as the square root of the loss rate determined here.

In this manner, when the light loss rate in the probe 10 is known, a correction signal is generated by the optical loss calculating section 25 and is input to the temperature calculating section 27. Then, the temperature calculation section 25
Then, a correction amount corresponding to the amount of light loss in the probe 10 during non-measurement is stored.

(2) Temperature measurement At this time, the air cylinder 82 is in a contracted state due to the signal from the dirty reference surface driving device 83, the reference surface 8 is not on the hood 1, and the hood 1 is open. Further, the optical switch 21 causes the optical fiber 5 to face the optical fiber 5B. In this state, infrared rays from the disk D enter the probe 10 through the hood 1, the optical path is bent by the reflector 2, passes through the infrared introduction tube 14, passes through the transmission window 3, the condensing lens 4, and enters the optical fiber 5. Ru.

After this, the infrared rays travel through the optical fiber 5 and switch to the optical switch 21.
is input into the optical fiber 5B. The amount of infrared light propagated by the optical fiber 5B is detected by the infrared detector 26, and a detection signal is sent to the temperature calculation section 27. Temperature calculation section 2
7 stores a correction amount corresponding to the amount of light loss in the probe 10 when the temperature is not measured, the detected infrared light amount is corrected according to this correction amount, and the correct amount of infrared rays can be determined by calculation. The correct temperature of disk D is determined.

As explained above, according to the infrared thermometer of the present invention,
Contamination of the measurement probe can be minimized, and even if the measurement probe becomes contaminated, the amount of infrared rays lost due to contamination can be determined. temperature measurement.

In the embodiment shown in FIG. 3, if the infrared detector 26 is arranged next to the photodetector 24, the optical switch 21
It becomes a state where it is not necessary to provide .

〔Effect of the invention〕

As explained above, according to the infrared thermometer of the present invention,
This has the effect that contamination of the measurement probe can be minimized, and even if the measurement probe becomes contaminated, temperature measurement can be performed with perfect accuracy.

[Brief explanation of drawings]

FIG. 1 is a basic configuration diagram of an infrared thermometer of the present invention, and FIG. 2 is a sectional view of a probe of an embodiment of an infrared thermometer of the present invention.
FIG. 3 is a block diagram showing the configuration of a temperature measuring device according to an embodiment of the infrared thermometer of the present invention, FIG. 4 is a perspective view showing an example of the internal configuration of the optical switch in FIG. 3, and FIG. ), (b
) is an explanatory diagram showing the operation of the optical switch in FIG. 4, FIG. 6 is a configuration diagram of a conventional infrared thermometer, FIG. 7 is a sectional view showing details of the probe in FIG. 6, and FIG. FIG. 3 is a cross-sectional view showing details of block A in the figure. 1...Hood, 2...Reflector, 3...Transmission window, 4
...Condensing lens, 5...Optical fiber, 8...Reference surface, 10...Probe, 20...Temperature measuring device, 22
...half mirror 223...light emitting means, 24...
Light receiving means, 24... Photodetector, 25... Optical loss calculation section, 26... Infrared detector, 27... Temperature calculation section,
28... Temperature display section, 50... Vacuum device, 60...
- Optical loss calculation means, 70... Infrared ray amount correction means, D.
...object (disk). Principle configuration diagram of the present invention Practical diagram of one embodiment of the present invention Configuration example of the optical switch in Figure 3 (a) (b) Operation diagram of the optical switch in Figure 4 Conventional infrared thermometer diagram 6. Cross-sectional view of the probe in Figure 6. Figure 7. Detailed view of section A in Figure 6.

Claims (1)

[Scope of Claims] An infrared thermometer that collects infrared rays emitted by an object from a hood (1) and measures the temperature of the object from the amount of the collected infrared rays using a temperature measuring device (20), the hood ( a reference surface (8) with a constant light reflectance provided in the opening of 1); and a reference surface driving device (80) that moves the reference surface (8) to open the hood (1) during temperature measurement. , a half mirror (22) provided in the infrared path in the temperature measuring device (20), a light emitting means (23) provided on the input side of the half mirror (22), and the half mirror (22). A light receiving means (24) provided on the output side of the light receiving means (24), and a light loss determined by the amount of light emitted by the light emitting means (23), the amount of light received by the light receiving means (24), and the reflectance of the reference surface (8) when the temperature is not measured. a light loss calculation means (60) for calculating the rate; and an infrared amount correction for correcting the amount of infrared rays input to the temperature measurement (20) based on the light loss rate from the light loss calculation means (60) during temperature measurement. an infrared thermometer comprising means (70).