JPH06321676A - Image furnace - Google Patents

Abstract

PURPOSE:To measure the temp. of samples fixed in a vessel without contact. CONSTITUTION:The bielliptic type image furnace is shown. Heat light sources (2a, 2b) set at first focal points emit IR rays of <=5mum wavelength. The IR rays are reflected by spheroid reflection mirrors (1a, 1b) and are condensed to second focal points to heat the samples (5a, 5b) which are to be heated and are set there to form molten zones 6. The transparent vessel 12 for fixing and housing the samples(5a, 5b) is mounted via a holder 4b on the front end of a shaft 3b to be put into and out of a Tee type furnace core tube 7b. The furnace core tube 7b consists of quartz glass which allows the transmission of the IR rays of <=5mum wavelength and the vessel 12 consists of sapphire, etc., which allows the transmission of the IR rays of >=5mum wavelength. The IR rays of >=5mum wavelength emitted from the samples and the molten zones are guided to the furnace core tube 7b and arrive at a window 8 where the IR rays transmit a protective plate 9b consisting of sapphire and enter a detector 10b which senses the IR rays of >=5mum wavelength.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image furnace used for crystal growth and the like, and more particularly to a mounting structure for a heated sample for non-contact measurement of a sample temperature during heating.

[0002]

2. Description of the Related Art In an image furnace, the inner surface of the furnace is composed of a spheroidal reflector, a heat source is arranged near the first focal point of the spheroidal surface, and heat rays are concentrated on a sample arranged near the second focal point. ,
This is a device for heating a sample.

In this image furnace, the reflecting mirror is a single ellipsoidal type having only one spheroid, and the reflecting mirror is a combination of two spheroids having a second focal point. A bi-elliptical type, and a multi-elliptical type in which a reflecting mirror is composed of a combination of three spheroids and shares a second focus,
There are various types such as.

Although the sample temperature can be measured directly by a thermocouple or the like, the image furnace which enables non-contact measurement is of a type using a single tube core tube (FIG. 2) and a T-shaped type. There is a type using a mold core tube (Fig. 3). 2 and 3
The image furnaces shown in (2) are all bi-elliptical image furnaces, which are proposed by the applicant.

Specifically, the bi-elliptical type image furnace shown in FIG. 2 has been disclosed in Japanese Patent Application Laid-Open No. 60-205178 and is already known, but non-contact temperature measurement by infrared rays having a specific wavelength of 5 μm or less is possible. It can be done. On the other hand, the bi-elliptical image furnace shown in FIG. 3 has not been disclosed (Japanese Patent Application No. 4-17328).
No.), it is possible to measure the non-contact degree by infrared rays having a specific wavelength of 5 μm or more. Hereinafter, the structure of the non-contact temperature measurement in the conventional image furnace will be described with reference to FIGS. 2 and 3.

In FIG. 2A (transverse cross-sectional view), the inner surface of the furnace is provided with two spheroidal reflectors 1a and 1b so as to share a second focal point (near the center in the figure) with each of the first spheroidal reflectors. The spheroidal reflector 1 is formed by arranging the focal points so as to face each other in a horizontal plane.
The thermal light source 2a is arranged near the first focal point of a, and the thermal light source 2b is arranged near the first focal point of the spheroidal reflecting mirror 1b. The infrared rays emitted by these heat sources are spheroidal mirrors (1a,
It is reflected by 1b) and condensed at the second focal position.

These heat sources are halogen lamps and the like, and the filaments (2 _1a , 2 _1b ) are contained in a bulb made of quartz glass (2 _2a , 2 _2b ).
Quartz glass has a transmission wavelength of 5 μm or less and absorbs infrared light having a wavelength longer than that, but the quartz glass (2 _2a , 2 _2b ) shown in FIG. 2 has a specific wavelength λ of 5 μm or less.
It is made of a material that absorbs infrared rays without transmitting them.

In the vicinity of the second focal point, B in FIG. 2 (longitudinal sectional view)
As will be described in detail, a rod-shaped sample to be heated and the like are arranged in the up-down direction orthogonal to the arrangement direction of the two heat sources. Specifically, an upper shaft 3a and a lower shaft 3b are provided in a furnace wall facing vertically in the vicinity of the second focal point so that they can move in and out of the furnace, and holders (4a, 4
The sample to be heated (5a, 5b) is attached via b). Sealing materials (11a, 11b) made of O-rings are inserted on both shafts to ensure the airtightness inside the furnace.

The distance between the opposing tip positions of the upper sample 5a and the lower sample 5b is adjusted and set by operating both shafts to move in and out. The opposing tips are heated by the infrared rays emitted from the filaments (2 _1a , 2 _1b ), A melting zone 6 is formed.

Then, the cylindrical single tube furnace core tube 7a is fixed at both ends thereof to the furnace wall vertically facing in the vicinity of the second focal point so as to accommodate the shaft and the sample. The single-tube furnace core tube 7a is made of general quartz glass capable of transmitting infrared rays having a specific wavelength λ of 5 μm or less, and shields the upper and lower heated samples (5a, 5b) and the melting zone 6 from the outside, and Fill ambient gas with inert gas,
Further, from the gas generated by them, a spheroidal reflector (1a,
It is provided for the purpose of protecting 1b).

Next, on the furnace wall facing the vicinity of the second focal point,
Although the window 8 is provided so that the heating state of the sample to be heated (5a, 5b) and the formation state of the melting zone 6 can be visually confirmed, the temperature of the sample to be heated (5a, 5b) and the temperature of the melting zone 6 can be confirmed. In order to measure the temperature, a bandpass filter 9 is provided on the outer surface of the furnace wall of the window 8 to pass only infrared rays having a specific wavelength λ of 5 μm or less. In order to secure the airtightness in the furnace, the bandpass filter 9 is also provided with a sealing material 11c made of an O-ring or the like.

That is, of the infrared rays emitted from the sample to be heated (5a, 5b) and the melting zone 6, the infrared ray having a specific wavelength λ of 5 μm or less passes through the furnace core tube 7a and then passes through the bandpass filter 9 and is set to the outside of 5 μm. It is introduced into the detector 10a having sensitivity to the following specific wavelength λ. The output of the detector 10a is
The sample to be heated (5
a, 5b) and the temperature value and temperature distribution of the melting zone 6 are displayed.

At this time, among the infrared rays emitted from the filaments (2 _1a , 2 _1b ), the infrared rays having a specific wavelength λ of 5 μm or less are absorbed by the quartz glass (2 _2a , 2 _2b ) and the detector 10a.
The temperature corresponding to the specific wavelength λ can be accurately measured.

In short, the image furnace shown in FIG. 2 has a wavelength of 5 μm among infrared rays emitted from the filaments (2 _1a , 2 _1b ).
Since infrared rays with a specific wavelength λ of m or less jump into the detector 10a through the window 8 and accurate temperature measurement cannot be performed, the quartz glass (2 _2a , 2 _2b ) that is a bulb is made of a material that absorbs the specific wavelength λ. Of.

However, as a result of the subsequent examination, the bulbs (2 _2a , 2 _2b ) were irradiated with the infrared rays emitted from the filaments (2 _1a , 2 _1b ).
Is heated and reaches a high temperature of several hundred degrees [° C] during lighting,
It was revealed that infrared rays of the specific wavelength λ were emitted from the surface of the bulbs (2 _2a , 2 _2b ), and accurate temperature measurement could not be performed yet.

Next, referring to FIG. 3, the image furnace is
In view of the fact that quartz glass generally has a property of absorbing and not transmitting infrared rays having a wavelength of 5 μm or more, a T-shaped furnace core tube 7b is used as a furnace core tube made of quartz glass, and the shaft (3a, 3
b), the sample to be heated (5a, 5b) and the melting zone 6 are housed, and the path extending from the predetermined range near the melting zone 6 to the window 8 is wrapped and the wavelength 5 μ emitted in the predetermined range near the melting zone 6
Infrared rays of m or more can reach the window 8 without any trouble,
Further, a protective plate 9b made of sapphire or the like which transmits infrared rays having a wavelength of 5 μm or more is provided on the outer surface of the furnace wall of the window 8, and 5
A detector 10b having sensitivity to a specific wavelength of μm or more is provided.

In the structure shown in FIG. 3, the heat source (2
Infrared rays having a wavelength of 5 μm or less emitted by a, 2b) pass through the T-shaped furnace core tube 7b and reach the detector 10b.
Since 0b is not sensed, the quartz glass forming the bulb of the heat source (2a, 2b) may be made of a material that absorbs infrared rays with a specific wavelength of 5 μm or less, and also absorbs infrared rays with a wavelength of 5 μm or more. It may be made of a general material.

[0018]

As described above, in the image furnace using the T-shaped furnace core tube, the temperature of the sample to be heated or the melting zone can be accurately measured by infrared rays having a wavelength of 5 μm or more without contact. In recent years, as a sample to be heated, one that may generate a gas such as arsenic that is toxic to the human body has been used.In such a case, a closed container enclosing the sample to be heated is placed on either the upper side or the lower side. It is necessary to attach it to one shaft and arrange it in a T-shaped furnace core tube, and heat the sample in the closed container to form a molten zone.

In addition to the method shown in FIG. 3 as a method for setting the sample to be heated in the T-shaped furnace core tube, the shaft is either on the upper side or the lower side, and the sample to be heated has a side end surface. There is a method of fixing in an open tubular container, attaching the tubular container to one shaft thereof, and disposing the tubular container in a T-shaped furnace core tube. In this case as well, the sample is heated in the cylindrical container to form a melting zone.

However, conventionally, since the closed container and the cylindrical container used for such an application are generally made of quartz glass similar to the furnace core tube, the sample or the sample being heated in the closed container or the cylindrical container is used. Among the infrared rays emitted from the melting zone, infrared rays having a wavelength of 5 μm or more are absorbed by the closed container or the cylindrical container and cannot reach the detector, which causes a problem that the temperature cannot be measured. At that time, it is possible to use a detector having sensitivity to a specific wavelength of 5 μm or less, but in this case, infrared rays emitted from a heat source are also detected, which is not appropriate.

The present invention has been made in view of such conventional problems, and an object thereof is to provide an image furnace capable of accurately measuring the temperature of a sample heated and melted in a container in a non-contact manner.

[0022]

In order to achieve the above object, the image furnace of the present invention has the following constitution. That is, in the image furnace of the present invention, the inside surface of the furnace is composed of a spheroidal mirror having a first focus and a second focus; a heat source such as a halogen lamp provided near the first focus; A sample to be heated which is provided in the vicinity of a second focus and is heated by infrared rays emitted from the heat source; and an infrared ray emitted from the sample to be heated, which accommodates the sample to be heated and corresponds to the vicinity of the second focus. A T-shaped furnace core tube leading to a window opened in the furnace; and introducing infrared rays emitted from the furnace out of the furnace into a temperature detector sensitive to infrared rays having a wavelength of 5 μm or more, and the temperature of the sample to be heated. An image furnace for measuring the temperature; a transparent container used when setting the sample to be heated in the T-type furnace core tube is made of a material such as sapphire that transmits infrared rays having a wavelength of 5 μm or more; It is a feature.

[0023]

Next, the operation of the image furnace of the present invention constructed as described above will be described. In the image furnace of the present invention, a transparent container, which is a closed container or a cylindrical container for setting a sample to be heated in a T-shaped core tube, is made of a material such as sapphire which transmits infrared rays having a wavelength of 5 μm or more. Is done.

Therefore, even if the sample emits a gas toxic to the human body, the temperature of the sample heated and melted in the closed container can be accurately measured without contact.

[0025]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an image furnace according to an embodiment of the present invention. The same components as those in FIG. 3 are designated by the same reference numerals. Hereinafter, the description will focus on the part relating to the present invention.

In FIG. 1, the shaft is limited to the lower side 3b, and the transparent container 12 is attached to the tip of the lower shaft 3b through the lower holder 4b. The sample to be heated (5a, 5b) is placed in the transparent container 12. ) Is fixedly placed.

The transparent container 12 is made of a material that can also transmit infrared rays having a wavelength of 5 μm or more, for example, sapphire, and is a closed container for enclosing and fixing the heated sample (5a, 5b) or simply fixing the heated sample (5a, 5b). It is a cylindrical container having an end face opening.

In this way, the infrared rays having a wavelength of 5 μm or more emitted from the sample to be heated (5a, 5b) and the melting zone 6 can pass through the transparent container 12 and reach the detector 10b without any trouble. The temperature of the sample to be heated and melted can be accurately measured by contact.

[0029]

As described above, in the image furnace of the present invention, a transparent container, which is a closed container or a cylindrical container for setting the sample to be heated in the T-type core tube, is provided with infrared rays such as sapphire having a wavelength of 5 μm or more. Since it is formed of a material that also permeates through, it is possible to accurately measure the temperature of a sample that heats and melts in a closed container in a non-contact manner, even if it is a sample that emits a gas that is toxic to the human body. . Further, there is also an effect that the shaft for inserting the sample into the furnace is only one on one side and the operation and the structure can be simplified.

[Brief description of drawings]

FIG. 1 shows an image furnace according to an embodiment of the present invention.
Is a horizontal sectional view, and B is a vertical sectional view.

2A and 2B show an image furnace using a conventional single tube furnace core tube, in which A is a transverse sectional view and B is a longitudinal sectional view.

3A and 3B show an image furnace using a conventional T-shaped furnace core tube, in which A is a transverse sectional view and B is a longitudinal sectional view.

[Explanation of symbols]

 1a, 1b spheroidal reflector 2a, 2b heat source 3b lower shaft 4b lower sample holder 5a upper sample 5b lower sample 6 melting zone 7b T-shaped furnace core tube 8 window 9b protective plate 10b detector 12 transparent container

Claims (1)

[Claims] 1. A furnace inner surface formed of a spheroidal mirror having a first focus and a second focus; a heat source such as a halogen lamp provided near the first focus; and a vicinity of the second focus. A sample to be heated, which is heated by infrared rays emitted from the heat source, and which accommodates the sample to be heated and opens the infrared rays emitted from the sample to be heated on the furnace wall corresponding to the vicinity of the second focal point. T-shaped core tube leading to the window;
Infrared rays emitted from the window to the outside of the furnace with a wavelength of 5
In an image furnace in which a temperature detector sensitive to infrared rays of μm or more is introduced to measure the temperature of the sample to be heated; a transparent container used when setting the sample to be heated in the T-type furnace core tube is An image furnace characterized by being made of a material such as sapphire which transmits infrared rays having a wavelength of 5 μm or more;