JPH1019676A - Infrared light source device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To extend the life of a light source and reduce the flicker noise by supplying an alternating current having a specified frequency or more to a metal heating element, and heating a ceramic light emitting body to emit a light. SOLUTION: An infrared ray having a prescribed wavelength is extracted from the infrared ray from an infrared light source device 52 by a spectroscope 54 to emit a sample chamber 56. The sample chamber 56 collects the transmitted light, and a desired data processing is performed by a data processing device 60 from the detected 58 infrared information. The infrared light source means 62 of the light source device 52 has a metal layer heating element heated by current-carrying and a ceramic light emitting body which coversits circumference and emits an infrared ray by heating. A control means 66 controls the output voltage of an ac driving means 64 on the basis of the luminance information of a luminance measuring part 68 so as to constantly keep the luminance of the infrared ray generated from the light source means 62. The driving means 64 converts the supplied power from a commercial power-source 70 of 50-60Hz to 80Hz or more and supplies the resulting power to the light source means 62. Thus, flicker noise is reduced, and a long life of 500 hours or more can be ensured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an infrared light source device, and more particularly to an improvement of a lighting mechanism thereof.

[0002]

2. Description of the Related Art An infrared light source device is well known as a light source such as an infrared spectrophotometer or a Fourier-exchange infrared spectrophotometer, and these infrared light source devices generally include ceramics which generate infrared light by heating. A luminous body made is used.
As the ceramic light emitting element, a direct light emitting method in which an electric current is applied to the ceramic itself to generate heat and emit light, or a heating element made of a metal wire such as tungsten is embedded in the ceramic light emitting element, and a current is applied to the metal heating element. The heat generating element generates heat, and the ceramic light emitting element is further heated to generate infrared light. The direct light-emitting method has the advantage of a simple structure, but on the other hand, the ceramics that make up the light-emitting body do not conduct much current, so the infrared light emission efficiency is low. The external light source device has advantages.

[0003]

However, when the infrared light source device of the indirect light emitting method is turned on by a direct current, a metal heating element embedded in the ceramic light emitting element causes migration in a ceramic called migration. Insulation breakdown occurs due to migration of ions, and the life is extremely shortened.
That is, the infrared light source device of the indirect light emission system is usually configured as shown in FIG.

The infrared light source 10 shown in FIG. 1 includes a metal heating element 12 that generates heat when energized, and a ceramic light emitting element 14 that covers the outer periphery of the metal heating element 12 and generates infrared rays by heating. . And the metal heating element 1
Reference numeral 2 denotes a metal wire that is drawn in a zigzag manner in a ceramic light emitting body 14, and is energized by applying a voltage difference to both ends of the metal wire 12 to heat and emit the ceramic light emitting body. . However, the gap d between the relative portions of the metal wires 12 is set to be relatively small, and as a result, insulation breakdown due to the movement of ions between the opposed metal wires 12 occurs.

On the other hand, when the current supplied to the metal heating element is an alternating current, the dielectric breakdown due to the migration as described above is less likely to occur and the life is extended, but on the other hand, flicker noise or the like is generated. Alternatively, a new problem such as a decrease in long-term stability of light luminance occurs. SUMMARY OF THE INVENTION The present invention has been made in view of the problems of the related art, and has as its object to provide a stable and long-life infrared light source device.

[0006]

In order to achieve the above object, an infrared light source device according to the present invention comprises a wire-shaped metal heating element which generates heat when energized, and an outer periphery of the heating element.
A ceramic luminous body that generates infrared rays by heating,
And an AC driving means for supplying an AC current of 80 Hz or more to the heating element of the infrared light source means. Further, in the device according to the present invention, it is preferable that the AC current supplied by the AC driving means is a rectangular wave AC current.

In the apparatus according to the present invention, it is preferable that the apparatus further comprises a luminance detecting means for measuring the luminance of the luminous body, and that the AC driving means controls the voltage of a driving power supply supplied to the infrared light source means based on the luminance. It is. In the apparatus according to the present invention, it is preferable that the apparatus further includes a temperature measuring unit that measures the temperature of the metal heating element, and that the AC driving unit controls the voltage of the driving current supplied to the infrared light source unit based on the output. is there.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The infrared light source device according to the present invention can be driven by an alternating current of 80 Hz or more as described above, so that flicker noise can be reduced and a long life of 500 hours or more can be ensured. Further, by setting the driving current supplied to the metal heating element to a rectangular wave alternating current of 80 Hz or more, flicker noise can be further reduced, light luminance can be easily adjusted, and long-term stability can be achieved. . Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. FIG. 2 shows a schematic configuration of an infrared spectrophotometer using the infrared light source device according to the present invention.

The infrared spectrophotometer 50 shown in FIG. 1 includes an infrared light source device 52, a spectroscope 54 for extracting infrared light of a predetermined wavelength from infrared light emitted from the infrared light source device 52, A sample chamber 56 for irradiating the sample with infrared light of a predetermined wavelength emitted from the spectroscope 54 and collecting the transmitted light or reflected light thereof;
A detector 58 for detecting infrared light reflected or transmitted by the sample in the sample chamber 56; and a data processing device 60 for performing desired data processing based on the infrared light information detected by the detector 58. . The infrared light source device 52, which is a feature of the present invention, includes a metal heating element that generates heat by energization and a ceramic light emitting element that covers the outer periphery of the metal heating element and generates infrared light by heating, as in FIG. An infrared light source means 62 having a body, an AC drive means 64 for supplying a drive current to a metal heating element of the infrared light source means, and the AC drive means 64
And control means 66 for controlling the driving state of.

In this embodiment, the control means 66
Is connected to a luminance measuring unit 68 for measuring the luminance of the infrared light generated by the infrared light source means 62, and by giving an output voltage control instruction to the AC driving means 64 based on the luminance information, The brightness of the infrared light generated by the means 62 is kept constant. The infrared light source device 52 according to the present embodiment is configured as outlined above, and its operation will be described next with reference to FIGS. The AC driving means 64 of the infrared light source device according to the present embodiment is supplied with power from a commercial power supply 70 of 50 Hz to 60 Hz, converts the power into an AC current of 80 Hz or more, and supplies it to the infrared light source means 62.

That is, as shown in FIG.
Hz alternating current is supplied to the infrared light source means 62,
The traveling direction of the ions moving in the gap d between the metal wires shown in FIG. 1 is also changed at a cycle of 80 Hz, and the possibility of dielectric breakdown is extremely reduced. As a result,
As shown in FIG. 4, the life of the infrared light source at 200 Hz or less at 50 Hz to 60 Hz becomes 500 hours or more, which is practically sufficient. Further, the infrared light source means 6
2B is as shown in FIG. 3B, and the fall time t of the driving power supplied to the metal heating element is shortened. As a result, flicker noise is reduced,
Stable lighting is possible despite AC lighting.

FIG. 5 shows an infrared light source device according to a second embodiment of the present invention, corresponding to FIG. What is characteristic in the present embodiment is that the drive current output from the AC drive means 64 is a rectangular wave AC current of 80 Hz or more. As a result, the power supplied to the infrared light source means 62 is always constant as shown in FIG.
As can be understood from comparison with (B), flicker noise can be further reduced and voltage adjustment is easy, so that long-term stability of light luminance can be easily maintained.

FIG. 6 shows the main part of the AC driving means suitably used in the present embodiment. The AC driving means 64 shown in FIG. 7 includes a rectifying / constant-pressure converting section 80 for rectifying and converting a 50 Hz to 60 Hz sine wave AC current supplied from a commercial power supply 70, and driver transistors 82 and 84. , 84 on / off control alternately, and the driver 8
6, a switching transistor 8 that is turned on / off in accordance with on / off of the driver transistors 82 and 84
8, 90, 92, 94.

Then, in synchronism with the driver transistors 82 and 84, which are turned on / off at a cycle of 80 Hz or more, the constant-voltage DC current supplied from the rectifying / constant-pressure converting unit 80 is converted into a rectangular wave by the rectangular wave forming unit 96. Convert. By supplying a rectangular wave AC current of 80 Hz or more to the infrared light source means 62 by the AC drive means having the simple configuration as described above, almost no flicker noise is generated and the long life of the infrared light source means is measured.

In the above-described embodiment, the luminance of the infrared light emitted from the infrared light source is monitored, and a change in the luminance is fed back to the control means 66. In this case, it is possible to easily increase or decrease the rectangular wave voltage to keep the luminance constant. In this case, a control signal may be given to the rectification / constant-pressure converter 80, and voltage control may be performed at a DC current stage where control is easy. Instead of monitoring the brightness, it is also preferable to directly or indirectly measure the temperature of the heating element of the infrared light source means and feed back the change to the control means 66 to keep the brightness of the light source constant. It is.

[0016]

As described above, the infrared light source device according to the present invention supplies an alternating current of 80 Hz or more to the metal heating element to heat and emit the ceramic light emitting element. It is possible to reduce the flicker noise as the life is extended.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of an infrared light source means to which the present invention is applied.

FIG. 2 is an explanatory diagram of an infrared spectrometer using the infrared light source device according to the present invention.

FIG. 3 is an explanatory diagram of an operation of a characteristic AC driving means in the present invention.

FIG. 4 is an explanatory diagram showing the relationship between the frequency of a drive current supplied to a metal heating element and the life of a light source.

FIG. 5 is an explanatory diagram of an operation of the infrared light source device according to the second embodiment of the present invention.

FIG. 6 is a detailed explanatory diagram of an AC drive unit used in the infrared light source device according to the second embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Infrared light source 12 ... Metal heating element 14 ... Ceramic light emitting body 52 ... Infrared light source device light source device 62 ... Infrared light source means 64 ... AC drive means

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Seichi Kashiwara 2967 Ishikawacho, Hachioji-shi, Tokyo 5 Japan Spectroscopy Corporation

Claims (4)

[Claims] 1. An infrared light source means comprising: a wire-shaped metal heating element that generates heat when energized; a ceramic light emitting element that covers an outer periphery of the heating element and generates infrared rays by heating; An AC driving means for supplying an AC current of 80 Hz or more to the heating element of (1). 2. The infrared light source device according to claim 1, wherein the AC current supplied by the AC driving means is a rectangular wave AC current. 3. An apparatus according to claim 1, further comprising: a luminance detecting means for measuring the luminance of the luminous body, wherein the AC driving means controls the voltage of a driving current supplied to the infrared light source means based on the luminance. An infrared light source device characterized by the above-mentioned. 4. The apparatus according to claim 1, further comprising temperature measuring means for measuring the temperature of the metal heating element, and controlling the voltage of the driving current supplied to the infrared light source means by the AC driving means based on the output of the temperature measuring means. An infrared light source device.