JPH07282785A - Infrared ray light source - Google Patents

Abstract

PURPOSE:To efficiently take out an infrared beam by constituting the jointing surface of both materials of a transmitting window and a bulb main body, jointing at the jointing surface, so that a glass material and the material of either a metal or a semiconductive material can be contacted to joint by using an electrostatic joint device. CONSTITUTION:A Si base plate 20 and a glass base plate 21 are heated to e.g. 300-500 deg.C by a heater 22, and thereto a D.C. voltage of 300-1000V is applied with the Si base plate 20 side as a positive electrode. Then a movable ion such as Na in a glass member is moved to form a space electric charge in the vicinity of the interface of a glass 21. Since the space electric charge is induced on the surface of the base plate 20, large electrostatic force is applied to the vicinity of the interface to promote the close adhesion between both surfaces. Inter-atomic jointing is formed via oxygen on the surface of the glass 21 in the interface to perform jointing. When gas is enclosed in a bulb, enclosing and air tightening are performed concurrently by performing electrostatic jointing in the atmosphere of the gas to be enclosed. The Si base plate 20 forming a transmitting window 8 can be transmitted by the beam of the wavelength of 1-20mum of an infrared rays, drawing the infrared rays from a window.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the structure of a light source which emits infrared rays, and more particularly to the structure of an infrared light source used in a component analysis device utilizing infrared rays.

[0002]

2. Description of the Related Art As one of the prior arts, an infrared light source of this kind is disclosed in Japanese Examined Patent Publication No. 1-13051 and FIG. 7 shows a block diagram of the disclosed infrared light source. In FIG. 7, reference numeral 61 is a block made of, for example, a box-shaped metal container, and 62 is an optical material having a high transmittance in the infrared wavelength region, for example, calcium fluoride.
A circular transparent window made of CaF ₂ and capable of transmitting infrared rays,
63 is integrally connected to the block 61, and the inside of the block 61 is
After the inert gas is filled in 64, a gas filled pipe that closes one end, 65 is a filament made of wire-formed tungsten in a coil shape, 66a and 66'a are spot-welded at the end of the filament 65, A hermetically sealed terminal lead made of a material such as Kovar, which supports
66b and 66'b are hermetically sealed terminals that connect the leads 66a and 66'a to a predetermined electric circuit. In addition, the seal of each component around the block 61 is adhesively sealed by adhesion or the like, and the block 61 is formed in a hermetically sealed structure.

In operation, the hermetically sealed terminal 66
When voltage is applied to both ends of b and 66'b, current flows to the coil of filament 65 through the hermetically sealed terminal leads 66a and 66'a, and heat is generated by conduction, and the temperature and emissivity of the filament 65 from the transmission window 62. It emits infrared rays in the wavelength range based on.

[0004]

The first problem in the infrared light source of the prior art is to seal a filament heated to a high temperature in a bulb and take out infrared rays from the filament as a box-shaped metal container, A method of fixing a transparent window made of an infrared transparent material to a part of this metal container with an adhesive is adopted, but in this type of tungsten lamp it is necessary to fill an inert gas in the bulb in order to extend the life. The airtightness of the fixed part is important. This fixed adhesive part is heated to a considerably high temperature due to the heat generation of the filament, so thermal stress is generated due to the difference in linear expansion coefficient between materials,
There is a problem that the life is shortened.

Further, in order to prevent this thermal stress, there is a drawback that the manufacturing process becomes complicated and the cost becomes high by laminating and fusion-welding materials having similar linear expansion coefficients. In addition, since the bonding step and the gas encapsulation step are separate from each other, there is a problem in that the cost is increased and it is difficult to reduce the size because an encapsulation pipe must be provided separately. The second problem in the conventional device is that the radiation efficiency of infrared rays is low. Infrared rays emitted from the filament are emitted not only toward the transmission window but also in all the surrounding directions.However, in a simple metal container like the conventional device, infrared light is reflected and absorbed by the surrounding metal containers, and heat is generated. As a result, the temperature rises and the infrared light that can be extracted from the transmission window decreases.

Further, the light traveling toward the transmission window is also reflected by the surface thereof and is lost, so that it is necessary to minimize the reflection loss. The present invention has been made in view of the above points, and an object thereof is to solve the above-mentioned problems, to make infrared rays as small as possible, to have a highly reliable seal, and to extract infrared rays efficiently. To provide a light source.

[0007]

In order to achieve the above object, according to the first means of the present invention, a light emitting portion for emitting infrared rays and a valve for hermetically sealing the light emitting portion are formed. In the infrared light source, the bulb has a transmission window made of a material that transmits infrared rays, which is provided in a part of the bulb, and a valve body, and at least a joint surface of both materials where the transmission window and the valve body are joined. Is configured such that the glass material is in contact with any one of metal and semiconductor materials, and is bonded by using electrostatic bonding means.

The material of the infrared transmitting window is silicon and the material of the valve body is Pyrex glass. The filament is made of a material having a high melting point that emits infrared rays and has conductivity. Further, according to the second means of the present invention, infrared ray reflecting means is provided on the inner surface of the valve body.

Further, the inner surface of the valve body is formed in any one of a paraboloidal surface, a spherical surface, and a spheroidal surface. Further, the transmission window made of an infrared transmission material is provided with antireflection coating on both sides of the transmission window. Further, the transmission window made of an infrared transmission material is provided with any one of a bandpass filter, a lowpass filter and a highpass filter in which a dielectric material is formed in multiple layers in the transmission window.

[0010]

With the above arrangement, according to the first means of the present invention, the bulb is formed of at least a part of the bulb and made of, for example, a transparent window made of a material that transmits infrared rays, such as silicon, and Pyrex glass. A valve body, and at least a bonding surface of both members for joining the transmission window and the valve body is configured so that a glass material and any one of a metal and a semiconductor material are in contact with each other, and are bonded by electrostatic bonding means. To do.

With this structure, the valve body and the infrared transmitting window material can be atomically diffusion-bonded to each other, so that they can be joined together with high strength and good airtightness. Since the electrostatic joining means can perform the joining by the temperature that gives the mobility of the internal ions of the glass member and the DC voltage that applies the electrostatic force to the joining surfaces of both members,
Bonding can be performed in any inert gas atmosphere.
Therefore, the gas injection pipe in the prior art can be eliminated.

As a means for solving the second problem, an infrared reflecting means is provided on the inner surface of the bulb accommodating the filament except the infrared transmitting window, and the inner surface shape is a paraboloidal surface, a spherical surface or a rotating surface. Elliptical, or
A means for preventing reflection of infrared rays is provided on at least one surface of the infrared transmitting window. With this configuration, the reflection means of the bulb reflects and collects the infrared rays emitted to the side surface and the back surface of the filament, prevents the infrared rays from being absorbed by the bulb material, and forms parallel rays or convergent rays through the infrared transmission window. can do. Moreover, the reflection loss can be reduced by the antireflection means of the infrared transmitting window, and the radiation intensity of the infrared rays emitted from the infrared transmitting window can be increased.

Further, by providing an optical band pass filter, an optical low pass filter or an optical high pass filter in which a dielectric film is formed in a multilayer film on the infrared transmitting window, it is possible to emit infrared rays having a wavelength selection characteristic.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic view of the essential parts of an infrared light source according to an embodiment of the present invention, FIG. 2 is a principle diagram for explaining electrostatic bonding means, and FIG. 3 is a schematic view of the essential parts of an infrared light source according to another embodiment. ,
FIG. 4 is an infrared emission distribution diagram according to the embodiment of FIG. 3, FIG.
FIG. 6 is a schematic view of a main part of an infrared light source according to another embodiment of the valve body.

FIG. 1 shows a first embodiment of the present invention. Figure 1
In the drawing, 1 is a filament made of, for example, tungsten in the form of a coil, and is fixed to the internal lead wires 2a, 2b made of, for example, an iron-nickel alloy core wire coated with copper by means such as spot welding. Internal lead wires 2a and 2b are dumet wires
One end is joined to 3a and 3b by spot welding or the like, and the other end is joined to external lead wires 4a and 4b so as to be electrically connected to an external electric circuit.

The dumet wires 3a and 3b form and enclose the beads 6 made of Pyrex glass. Dumet wire 3a, 3b
Since Pyrex glass and Pyrex glass have almost the same coefficient of linear expansion, airtightness can be maintained by fusing them together. An anchor 7 is installed on the bead 6. The anchor 7 supports the filament 1 by using, for example, molybdenum in order to prevent a short circuit due to the deformation of the filament 1.

Reference numeral 5 denotes a valve body for hermetically enclosing the filament 1. In one embodiment, the valve body 5 is made of Pyrex glass, and one end of the valve body is melt-bonded to the bead 6. The other end of the valve body is hermetically bonded to the infrared transmitting window 8 made of a silicon substrate by electrostatic bonding means described later. On both sides of the transmissive window 8, for example, an antireflection coating 9 such as an anti-reflective coating (anti-reflection coating) is provided in order to enhance transmission of infrared rays.
The amount of infrared rays emitted from the transmission window 8 is increased.

Further, a reflective film 10 for reflecting infrared light, for example, silver vapor-deposited is formed inside the valve body 5 as well.
The directivity of infrared rays is increased and the amount of emitted light is increased. 11 is a cap and is adhered to the valve body 5 with an adhesive material. The lead wires 4a and 4b are inserted into the pipes 12a and 12b made of resin or the like which is electrically insulating because the cap 11 is conductive when the cap 11 is a conductive material. The pipes 12a and 12b are fixed to the base 11 with an adhesive material.

Next, a method of assembling the valve having the above structure will be described. FIG. 2 is a principle diagram for explaining electrostatic bonding means which is a method of bonding the glass valve body 5 and the silicon transmission window 8. In FIG. 2, 20 is a silicon substrate
It is made of Si and is placed on the heater 22 by overlapping with the glass substrate 21. Reference numeral 23 is an electrode, and 24 is a DC power supply. heater
22 to set the silicon substrate 20 and the glass substrate 21 at 300 to 500 °
Heat to C and use the silicon substrate 20 side as an anode for 300 to 1000
A DC voltage of V is applied. When this voltage is applied, mobile ions such as Na in the glass member move, and space charges are formed near the interface of the glass 21. Since a charge equivalent to this space charge is induced on the surface of the silicon substrate 20 which is a conductor, a large electrostatic attractive force is exerted in the vicinity of the interface, and the adhesion between both surfaces proceeds.

Interatomic bonds are formed through the oxygen on the surface of the glass 21 at the closely contacted interface, and bonding is performed. When the gas is sealed in the valve, the sealing and the airtight bonding can be performed at the same time by performing electrostatic bonding in the atmosphere of the sealed gas. As the filling gas, helium, argon or the like can be used depending on the purpose. Next, the operation of the above configuration will be described. When voltage is applied to both ends of the external lead wires 4a and 4b, the Dumet wires 3a and 3b and the internal lead wire 2
An electric current flows through the filament 1 via a and 2b to generate heat by energization, so that light in the wavelength range corresponding to the emissivity and temperature of the filament material is emitted. Silicon substrate forming transparent window 8
Since 20 has a property of transmitting light of 1 to 20 μm in the infrared wavelength range, infrared rays can be taken out from this transmission window 8 and can be used as an infrared light source.

Further, instead of the antireflection coating 9 described in the above embodiment, an optical material having a high refractive index, for example, germanium Ge, selenium Se, zinc sulfide ZnS.
And an optical material having a low refractive index, such as sodium fluoride NaF, lithium fluoride LiF, and potassium bromide KBr, form an interference filter to form an interference filter and a bandpass filter. can do. It can also be a low pass filter with only high refractive index material or a high pass filter with only low refractive index material. With this configuration, it is possible to manufacture an infrared light source that emits a specific wavelength band in the infrared region.

In the embodiment of FIG. 1, of the infrared rays projected from the filament 1, only the infrared rays directed to the transmission window 8 are projected, but the method shown in the embodiment of FIG. Can be increased. In FIG.
The shape of the inner surface of the valve body 25 is, for example, a paraboloid of revolution, and the filament 1 is placed at the focal position. The reflective film 10 is formed on the inside of the valve body 25 by vapor deposition or the like,
Reflects infrared rays. The light emitted from the focal point of the paraboloid of revolution is reflected by the reflection film 10 and becomes all parallel light, so that the light intensity distribution emitted from the transmission window 8 is a circular distribution as shown in FIG. The distribution is high (with the reflective film 10) from (without the reflective film 10), and the light intensity can be increased.

Further, the inner surface of the valve body 25 has a spherical surface,
If a spheroidal surface is used and one of the focal points is located at the filament position, infrared rays can be condensed and the light intensity can be increased. In the above explanation, the valve body 5,
Although 25 has been described as a structure using Pyrex glass and the infrared transmission window 8 as a silicon substrate, the present invention is not limited to this combination, and similar effects can be obtained by directly bonding glass and a metal or semiconductor material. Obtainable. For example, in FIG. 5, the valve body 26 is a metal container made of Kovar or Invar, the infrared transmission window 8 is formed of a silicon substrate, and the Pyrex glass 27 is sandwiched between the valve body 26 and the infrared transmission window 8 and laminated. An infrared light source can be manufactured by bonding the bulb main body 26 and the Pyrex glass 27, which are made of metal, and then the Pyrex glass 27 and the infrared transmitting window 8 by electrostatic bonding as in the above description.

Further, instead of the silicon substrate of the infrared transmission window 8, for example, calcium fluoride CaF ₂ or barium fluoride Ba
There is a method shown in FIG. 6 as an electrostatic bonding method when various optical materials such as F ₂ are used as a single crystal that transmits infrared rays. A metal film 29 is formed on the outer peripheral portion on one side of the surface of a single-crystal infrared light transmitting window 28 of single crystal such as calcium fluoride CaF ₂ or barium fluoride BaF ₂ by means such as sputtering with a metal such as Kovar or Invar. Also, the valve body made of metal
A bulb can be formed of a single crystal material by electrostatically bonding Pyrex glass 30 to 26 and electrostatically bonding Pyrex glass 30 and metal film 29.

In the above description, the case where the filament is made of a refractory metal such as tungsten has been explained, but the filament is not limited to this and, for example, silicon carbide Si.
It is also possible to use a ceramic material such as C or molybdenum disilicide MoSi ₂ formed into a filament by forming it into a wire or processing.

[0026]

As described above, according to the constitution of the first means for solving the problems according to the present invention, as a means for hermetically sealing a high temperature filament and taking out infrared rays, at least a part of the sealing valve is provided with infrared rays. Since a window made of a transparent material is provided and the window and the valve body are directly or indirectly combined with a metal or semiconductor and a glass material to perform diffusion bonding between atoms using electrostatic bonding means, Unlike the bonding of the device, much higher airtightness can be obtained, high strength can be obtained even at high temperature, and the airtightness with very high reliability can be obtained for a long period of time.

Further, since this electrostatic joining means can be carried out in a normal gas atmosphere, when various gases for preventing the evaporation of the filament are filled, the joining is performed in this filled gas atmosphere so that the inside of the valve is filled. The desired gas can be enclosed, and the two steps of conventional bonding and gas enclosure can be integrated into one, resulting in cost reduction. Furthermore, the filling pipe for filling the gas and the mounting work thereof are unnecessary, and there is an effect that the cost can be reduced and the size can be reduced.

Further, according to the structure of the second problem solving means of the present invention, by providing means for reflecting infrared rays such as a foil film on the inner surface of the valve body other than the window for taking out infrared rays, as in the prior art. In this way, it is possible to prevent the absorption of infrared rays in the valve body and the large reflection loss in the transmission window, and to increase the infrared radiation efficiency. In addition, since this reflecting surface is formed as a paraboloid of revolution, a spherical surface, a spheroid, etc., and is configured to collect the emitted light of the filament, it is only necessary to use the emitted light from the front surface of the filament as in the prior art. Unlike the above, it is possible to use the emitted light to the side surface and the back surface, so that the radiation efficiency can be almost doubled, and at the same time, a miniaturized infrared light source with high energy density can be provided.

Furthermore, by providing a means for preventing the reflection of infrared rays on at least one surface of the window through which infrared rays are taken out, the reflection of infrared rays can be minimized and the radiation efficiency of infrared rays can be improved. . Furthermore, by providing an infrared light filter using a multilayer dielectric film on at least one surface of the window through which infrared light is taken out, it is possible to provide an infrared light source having wavelength selectivity in the infrared region. is there.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a main part of an infrared light source according to an embodiment of the present invention.

FIG. 2 is a principle diagram illustrating electrostatic bonding means.

FIG. 3 is a configuration diagram of a main part of an infrared light source according to another embodiment.

FIG. 4 is an infrared emission distribution chart according to the embodiment of FIG.

FIG. 5 is a main part configuration diagram of an infrared light source according to another embodiment of the valve body.

FIG. 6 is a configuration diagram of an essential part of an infrared light source according to another embodiment of the valve body.

[FIG. 7] FIG. 7 is a front view and (B) is a side view of the configuration of the main part of an infrared light source according to the prior art.

[Explanation of symbols]

 1, 65 Filament 2a, 2b Inner lead wire 3a, 3b Dumet wire 4a, 4b Outer lead wire 5, 25 Valve body 6 Bead 7 Anchor 8, 28, 62 Transmission window 9 Antireflection film 10 Reflective film 11 Base 12a, 12b Insulation Pipe 20 Silicon substrate 21 Glass substrate 22 Heater 23 Electrode 24 DC power supply 26 Metal bulb 27,30 Pyrex glass 61 Block 63 Gas filled pipe 64 Inside block 66a, 66a 'Hermetically sealed terminal lead 66b, 66b' Hermetically sealed terminal

Front page continuation (72) Inventor Masahiro Uno 1-1 Tanabe Nitta, Kawasaki-ku, Kawasaki-shi, Kanagawa Fuji Electric Co., Ltd.

Claims (7)

[Claims] 1. An infrared light source comprising a light emitting section for emitting infrared rays and a bulb for hermetically sealing the light emitting section. The bulb is provided in a part of the bulb and transmits infrared rays. A transparent window made of a material, and a valve body, and at least a bonding surface of the two materials at which the transparent window and the valve body are bonded to each other is made of a glass material and a metal or a semiconductor material. An infrared light source, which is configured to be in contact with each other and is bonded by using electrostatic bonding means. 2. The infrared light source according to claim 1, wherein the material of the infrared transmitting window is silicon and the material of the valve body is Pyrex glass. 3. The infrared light source according to claim 1, wherein an infrared reflecting means is provided on the inner surface of the valve body. 4. The infrared light source according to claim 3, wherein the inner surface of the bulb body is formed into any one of a paraboloid of revolution, a spherical surface and a spheroid. 5. The infrared light source according to claim 1, wherein the filament is made of a material having a high melting point and emitting infrared rays and having conductivity. 6. The infrared light source according to any one of claims 1 to 5, wherein the transmissive window made of an infrared transmissive material is provided with an antireflection coating on both sides of the transmissive window. Infrared light source. 7. The infrared light source according to claim 1, wherein the transmissive window made of an infrared transmissive material has a band-pass filter or a low-pass filter in which a multi-layered dielectric is formed on the transmissive window. Alternatively, an infrared light source is provided with any one of a high-pass filter.