JP7509356B2 - Discharge lamp, light source device, method for producing synthetic silica glass tube for discharge lamp or light source device, and light emitting member - Google Patents

Description

The present invention relates to discharge lamps such as excimer lamps, light source devices, and methods for manufacturing synthetic silica glass tubes.

In an excimer lamp, a high voltage is applied at high frequency between a pair of electrodes with a dielectric between them, creating an excimer discharge in a discharge space filled with a discharge gas, which then emits ultraviolet light. Ozone is generated by irradiating air with ultraviolet light.

In an excimer lamp equipped with a discharge vessel made of silica glass (quartz glass), visible light is emitted along with ultraviolet light by adjusting the type of silica glass, the processing conditions during manufacture, the type of discharge gas, etc. To allow the user to confirm that the lamp is on, for example, a window that transmits visible light is provided in the housing of the ozone generator, allowing the user to visually confirm (see Patent Document 1).

JP 2019-043786 A

Ozone generation using ultraviolet irradiation with excimer lamps does not produce nitrogen oxides, which are harmful substances. Therefore, it is not only used in unoccupied spaces such as disinfecting hospital rooms and cleaning semiconductors in factories, but is also in demand in spaces where people are present, such as homes, hotel rooms, restaurants, and public facilities.

Lamps and light source devices used in such environments exposed to the general public need to be excellent in terms of both functionality and lighting design, as they need to satisfy people's psychological and physiological needs. However, conventional commercial and industrial excimer lamps have not been developed or designed with consideration given to lighting design, including the psychological and physiological effects on people.

Therefore, there is a need to provide discharge lamps and light source devices with excellent lighting designs that take into account the psychological and physiological effects.

A method for manufacturing a synthetic silica glass tube for a discharge lamp or light source device, which is one aspect of the present invention, includes the steps of forming a synthetic silica glass tube, contacting the synthetic silica glass tube with a fluorescent material that emits fluorescence in the visible light wavelength range when exposed to ultraviolet light, and heat treating the synthetic silica glass tube at a temperature below the softening point of the synthetic silica glass tube. The fluorescent material includes, for example, at least one of copper, magnesium, gold, and indium.

The discharge lamp according to one aspect of the present invention includes a discharge section that emits ultraviolet light by discharge, and a light-emitting section that transmits ultraviolet light and visible light emitted from the discharge section together with the ultraviolet light, and emits fluorescence in the visible light wavelength range upon receiving the ultraviolet light. For example, the light-emitting section can be made to emit fluorescence by at least one of copper, magnesium, gold, and indium.

It is possible to configure the device so that visible light and fluorescent light are simultaneously visible as the emitted color of the light-emitting section. For example, the discharge is a weak discharge that occurs and disappears instantaneously, and the shape of the weak discharge can be seen.

A discharge vessel that houses the discharge section may be further provided, and the light-emitting section may be formed in at least a part of the discharge vessel. Alternatively, a discharge vessel that houses the discharge section and a lamp housing section that houses the discharge vessel may be further provided, and the light-emitting section may be formed in at least a part of the lamp housing section.

The light source device according to one aspect of the present invention includes a discharge lamp that emits ultraviolet light, and a light-emitting section that transmits ultraviolet light and visible light emitted from the discharge lamp together with the ultraviolet light, and emits fluorescence in the visible light wavelength range upon receiving the ultraviolet light.

The light-emitting member according to one aspect of the present invention is a tubular light-emitting member capable of housing a discharge lamp that simultaneously emits ultraviolet light and visible light, and transmits ultraviolet light and visible light, and emits fluorescence in the visible light wavelength range when exposed to ultraviolet light.

The present invention makes it possible to provide discharge lamps, light source devices, and the like with excellent lighting designs that take into account psychological and physiological effects.

1 is a schematic diagram of an excimer lamp (discharge lamp) according to a first embodiment. FIG. 11 is a schematic diagram of an excimer lamp according to a second embodiment. FIG. 13 is a schematic diagram of an excimer lamp according to a third embodiment. FIG. 13 is a schematic configuration diagram of a light source device according to a fourth embodiment. FIG. 13 is a diagram showing a table showing the relationship between the fluorescent material used and the visually recognized luminescent color.

Below, an embodiment of the present invention will be described with reference to the drawings.

Figure 1 is a schematic diagram of an excimer lamp according to the first embodiment.

The excimer lamp 10 comprises a discharge vessel 20, an inner electrode 30, and an outer electrode 40, and can be applied to, for example, an ultraviolet irradiation device. Here, the excimer lamp 10 is configured as a long lamp with a circular cross section, but it may have other shapes, such as a square lamp with a rectangular cross section. The discharge vessel 20 is filled with a discharge gas. For example, Xe, Ar or Kr gas, or a mixture of these gases, is filled.

The inner electrode 30 is disposed within the discharge vessel 20 and is covered with a dielectric 50 such as silica glass without being exposed to the discharge space. It is also possible to configure the inner electrode 30 in such a way that a foil-shaped inner electrode is embedded in a tubular dielectric 50 made of a silica glass tube by heating and melting it. The outer electrode 40 is disposed on the outer surface 20S of the discharge vessel 20 along the tube axis.

A voltage is applied between the inner electrode 30 and the outer electrode 40 from the lamp power supply (not shown) via a power supply line (not shown) connected to the ends of the inner electrode 30 and the outer electrode 40. This causes an excimer discharge in the discharge vessel 20, and ultraviolet light is emitted (see symbol L1).

The discharge here is a weak discharge that occurs and disappears instantaneously repeatedly. In a micro-discharge, a micro-discharge occurs locally along the radial direction of the discharge vessel 20 (local discharge), and ultraviolet light with a specific peak wavelength (e.g., 172 nm) is emitted. The applied voltage, its frequency, the enclosed gas pressure, etc. are determined so that a weak discharge occurs.

In addition to emitting ultraviolet light, the excimer lamp 10 also emits visible light (see symbol L2). The emission of visible light is achieved by selecting the type of synthetic silica glass tube that constitutes the discharge vessel 20, the heat treatment conditions, the type of discharge gas enclosed, the wavelength of the emitted ultraviolet light, and the like. By adjusting these factors, it is also possible to emit visible light in different wavelength ranges.

The discharge vessel 20 is made of a synthetic silica glass tube. The discharge vessel 20, i.e., the inside wall 20W of the discharge vessel 20 including the inner and outer surfaces, contains minute fluorescent material M in a scattered state. The fluorescent material M contains minute metals such as copper, magnesium, gold, or indium, or compounds thereof, and is scattered throughout the discharge vessel 20 along the tube axis. It may also be scattered in part.

The fluorescent material M has the property of emitting visible light when irradiated with ultraviolet light L1, and fluorescence (see symbol L3) in a visible light wavelength range different from the visible light L2 is emitted to the outside of the excimer lamp 10. On the other hand, since the fluorescent material M is dispersed on the outer surface 20S and/or inside the tube wall 20W, most of the ultraviolet light L1 and visible light L2 produced by the weak discharge pass through the discharge vessel 20 without being blocked by the fluorescent material M and are emitted to the outside of the excimer lamp 10.

As a result, while the excimer lamp 10 is on, visible light L2 and fluorescent light L3, which is visible light, are simultaneously visible along with ultraviolet light L1. Specifically, the visible light L2 allows the visibility of weak discharge parts where minute radial discharges occur at intervals along the tube axis direction, and the fluorescent light L3 allows the visibility of the shape of the discharge vessel 20. The fluorescent light L3 of the fluorescent material M does not block the visibility of the weak discharge parts of the excimer lamp 10. In other words, the shape of the weak discharge parts can be visually seen.

As described above, the wavelength ranges of the visible light L2 and the fluorescent light L3 vary depending on the type of discharge vessel 20, the fluorescent material M, etc., so by selecting them appropriately, it is possible to emit the visible light L2 and the fluorescent light L3 in the desired wavelength range. In addition, by visually checking the visible light L2 and the fluorescent light L3, the discharge state between the electrodes, i.e., the lamp operating state, can be confirmed from outside the lamp.

The discharge vessel 20 of the excimer lamp 10 can be manufactured as follows. First, a material that emits fluorescence in the visible wavelength range when exposed to ultraviolet light is brought into surface contact with the synthetic silica glass tube. For example, the above-mentioned metal or its compound is brought into contact with the entire synthetic silica glass tube using a rod-shaped tool. The contact area is then heat-treated at a temperature below the softening point of the synthetic silica glass tube. As a result, the fluorescent material is scattered on the surface and/or inside the tube wall of the synthetic silica glass tube, in a state in which ultraviolet light L1 and visible light L2 from the weak discharge can be transmitted through the discharge vessel 20 and the shape of the weak discharge area can be visually recognized. Note that the rod-shaped tool may be brought into contact with only a portion of the synthetic silica glass tube.

After manufacturing the synthetic silica glass tube containing the fluorescent material, a discharge lamp is manufactured through conventional lamp manufacturing processes such as electrode arrangement and heat treatment. Instead of contacting the fluorescent material with the surface of the synthetic silica glass tube, metal powder that serves as the fluorescent material may be placed inside the synthetic silica glass tube. In this case, by heating the silica glass tube from the outside below its softening point, the fluorescent material can be contained in a scattered state inside the synthetic silica glass tube.

As described above, according to this embodiment, the discharge vessel 20 of the excimer lamp 10 contains fluorescent material M in a scattered state inside the tube wall 20W. By making the discharge vessel 20 a vessel in which visible light L2 emitted by discharge together with ultraviolet light L1, and fluorescent light 3 emitted from the fluorescent material M can be simultaneously viewed, it is possible to provide lighting that leaves a strong psychological and physiological impression on the user without making major changes to the structure of conventional excimer lamps.

Next, the second embodiment will be described with reference to FIG. 2. In the second embodiment, the fluorescent material is dispersed in the dielectric material that covers the inner electrode.

Figure 2 is a schematic diagram of an excimer lamp according to a second embodiment. In the excimer lamp 100, fluorescent material M is contained in a scattered state in the dielectric 150 that covers the inner electrode 30. With this configuration, ultraviolet light L1, visible light L2, and fluorescent light L3 are emitted to the outside of the lamp, as in the first embodiment. Visible light L2 allows the band-shaped weak discharge portion along the tube axis direction to be visible, and fluorescent light L3 allows the shape of the dielectric 150 to be visible.

Next, a third embodiment will be described with reference to FIG. 3. In the third embodiment, a synthetic silica glass member containing a fluorescent material is placed inside the discharge vessel.

Figure 3 is a schematic diagram of an excimer lamp according to a third embodiment. The excimer lamp 200 is provided with a tubular member 260 that is open at both ends. The tubular member 260 is made of a synthetic silica glass tube and contains fluorescent material M. With this configuration, ultraviolet light L1, visible light L2, and fluorescent light L3 are emitted to the outside of the lamp, just like in the first embodiment. Visible light L2 allows the weak discharge portion to be seen, and fluorescent light L3 allows the shape of the tubular member 260 to be seen.

Next, a fourth embodiment of the light source device will be described with reference to FIG. 4. In the fourth embodiment, the fluorescent material M is dispersed in a tube that houses the excimer lamp.

Figure 4 is a schematic diagram of a light source device according to a fourth embodiment. Here, the light source device 400 is incorporated into an ozone generator 500, and an excimer lamp 40 is disposed in a flow path tube 440 through which a gas containing oxygen flows. When the lamp is turned on, the excimer lamp 40 radiates ultraviolet light L1 and visible light L2 to the outside of the lamp. The discharge vessel 420 does not contain fluorescent material M.

The flow path tube 440 is a tube manufactured according to the synthetic silica glass tube manufacturing process described above, and fluorescent material M is scattered on the surface of the synthetic silica glass tube and inside the tube wall 440W. The flow path tube 440 is configured as a light-emitting section that transmits ultraviolet light L1 and visible light L2 from the excimer lamp 40 and emits fluorescent light L3, allowing the user to simultaneously view the visible light L2 emitted together with the ultraviolet light L1 and the fluorescent light L3. In this way, a light source device with improved lighting design can be provided while using a conventional excimer lamp 10.

It is also possible to configure an excimer lamp equipped with a member that has a shape similar to that of the flow path tube 440 and functions as a lamp cover (lamp storage section). For example, a lamp can be configured with a lamp cover that contains scattered fluorescent material and is attached to a support stand directly above the excimer lamp. Also, a lamp cover may be equipped to a lamp other than an excimer lamp that emits visible light along with ultraviolet light.

The following experiment was conducted to confirm the simultaneous visibility of visible light and fluorescent light. Figure 5 shows a table showing the relationship between the fluorescent material used and the visible emission color.

The excimer lamps of Examples 1 to 4 correspond to the first embodiment, and are excimer lamps equipped with a discharge vessel containing the fluorescent material shown in FIG. 5 according to the manufacturing process described above for a synthetic silica glass tube (outer diameter 25 mm, axial length 200 mm). In the excimer lamps of Examples 1 to 4, copper oxide, magnesium oxide, gold thin film, and indium iodide powder were used as fluorescent materials, respectively. Comparative Example 1 is an excimer lamp equipped with a discharge vessel that does not contain fluorescent material.

A lamp filled with Xe gas was turned on in the discharge space. As a result, as shown in Figure 5, visible light and fluorescent light were simultaneously visible in the excimer lamps of Examples 1 to 4. On the other hand, only visible light due to discharge was visible in the excimer lamp of the comparative example.

10 Excimer lamp (discharge lamp)
20 Discharge vessel (light emitting part)
150 Dielectric (light-emitting part)
260 Tubular member (light emitting part)
400 Light source device 440 Flow path tube (light emitting part)
M Fluorescent material

Claims (11)

forming a synthetic silica glass tube;
a step of bringing a powdered fluorescent material, which emits fluorescence in the visible light wavelength range when exposed to ultraviolet light, into surface contact with the synthetic silica glass tube or disposing the powdered fluorescent material on the inside of the synthetic silica glass tube;
and a step of heat treating the synthetic silica glass tube at a temperature equal to or lower than the softening point of the synthetic silica glass tube. The method for manufacturing a synthetic silica glass tube for a discharge lamp or light source device according to claim 1, characterized in that the fluorescent material contains at least one of copper, magnesium, gold, and indium. a tubular discharge vessel that forms a discharge space in which ultraviolet light is radiated by discharge;
a tubular dielectric covering an inner electrode provided in the discharge vessel;
the discharge vessel and the dielectric transmit the ultraviolet light and visible light emitted in the discharge space together with the ultraviolet light,
A discharge lamp characterized in that a fluorescent material that emits fluorescence in the visible light wavelength range when exposed to the ultraviolet rays is scattered within at least a part of the tube wall of the discharge vessel or the dielectric. 4. The discharge lamp according to claim 3, wherein the visible light and the fluorescent light are simultaneously viewed as luminous colors. The discharge lamp according to claim 3 or 4, characterized in that the fluorescent material is scattered within at least a portion of the tube wall of the discharge vessel. a tubular discharge vessel that forms a discharge space in which ultraviolet light is radiated by discharge;
a tubular lamp housing that houses the discharge vessel;
the discharge vessel and the lamp housing transmit the ultraviolet light and the visible light emitted in the discharge space together with the ultraviolet light,
A discharge lamp, characterized in that a fluorescent material that emits fluorescence in the visible light wavelength range upon receiving the ultraviolet rays is scattered within at least a part of the tube wall of the lamp storage portion. 7. The discharge lamp according to claim 3 , wherein the fluorescent material contains at least one of copper, magnesium, gold, and indium. A discharge lamp according to any one of claims 3 to 7, characterized in that the discharge is a weak discharge that occurs and disappears instantaneously. a tubular discharge vessel that forms a discharge space in which ultraviolet light is radiated by discharge;
a tubular dielectric covering an inner electrode provided in the discharge vessel;
a tubular member having both ends open and disposed within the discharge vessel and surrounding the dielectric;
the discharge vessel and the tubular member transmit the ultraviolet light and visible light emitted in the discharge space together with the ultraviolet light,
A discharge lamp, characterized in that a fluorescent material that emits fluorescence in the visible light wavelength range upon receiving the ultraviolet rays is scattered within at least a portion of the tube wall of the tubular member. A discharge lamp that emits ultraviolet light;
a tubular member capable of housing the discharge lamp and transmitting the ultraviolet light and visible light emitted from the discharge lamp together with the ultraviolet light;
A light source device characterized in that a fluorescent material that emits fluorescence in the visible light wavelength range when exposed to the ultraviolet rays is scattered within at least a portion of the tube wall of the tubular member. A tubular member capable of housing a discharge lamp that simultaneously emits ultraviolet light and visible light,
A tubular member, characterized in that a fluorescent material that transmits the ultraviolet light and the visible light and emits fluorescence in the visible light wavelength range when exposed to the ultraviolet light is dispersed within at least a portion of the tube wall.

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