TWI440065B - Ultraviolet discharge lamp - Google Patents

Description

Ultraviolet discharge lamp

The present invention relates to an ultraviolet radiation discharge lamp used for performing polymerization or hardening of a polymer material by ultraviolet irradiation, for example, a liquid crystal panel manufacturing step, and more particularly, to select a coated phosphor or An ultraviolet discharge lamp having a film thickness and improved luminous efficiency.

An ultraviolet discharge lamp of JP-A-2002-358926 (Prior Art 1) forms an airtight container of a soda lime glass light-emitting tube that transmits ultraviolet light having a wavelength of 253.7 nm, and a discharge medium containing mercury and a rare gas is sealed inside the light-emitting tube. A pair of electrodes that initiate a low-pressure mercury vapor discharge is disposed inside the arc tube. Because of the inner surface of the arc tube, BaSi ₂ O ₅ :Eu, Ce (MeBa) emitting near-ultraviolet light having a wavelength of 320 to 400 nm, which is excited by a mercury glow line having a wavelength of 253.7 nm radiated by a low-pressure mercury vapor discharge of a discharge medium, is emitted. At least one of a phosphor such as Al ₁₁ O ₁₉ or YPO ₄ :Ce or LaPO ₄ :Ce or a combination thereof, the UV-A region having a high internal permeability to the ultraviolet curable resin and the ultraviolet curable resin The UV-C light with strong surface hardening force can be obtained simultaneously by one lamp.

According to the technique of the prior art 1, although the light of the UV-A region and the UV-C region can be simultaneously obtained by one lamp, the illuminance at a wavelength of 320 to 340 nm cannot be improved. In order to increase the illuminance of the wavelength domain, it is necessary to increase the number of the lamps accordingly, and there is a problem of how much the cost increases.

A first object of the present invention is to provide a specific fluorescent body for ultraviolet light emission capable of emitting short-wavelength light on a hot cathode low-pressure mercury lamp formed of a light-sodium tube of soda-lime glass, thereby improving illuminance. UV discharge lamp.

A second object of the present invention is to improve the efficiency of ultraviolet irradiation by combining the appropriate thickness of LaPO ₄ :Ce used as a phosphor for ultraviolet irradiation and an emission tube for transmitting a specific wavelength. Possible UV discharge lamps.

Hereinafter, the best mode for carrying out the invention will be described in detail with reference to the drawings.

Fig. 1 and Fig. 2 are views for explaining an embodiment of an ultraviolet discharge lamp of the present invention, Fig. 1 is a configuration view, and Fig. 2 is a cross-sectional view taken along line I-I' of Fig. 1. In addition, Fig. 1 is a view showing a configuration of a hot cathode low-pressure mercury lamp as an example of an ultraviolet discharge lamp, partially shown in a broken state.

In Fig. 1 and Fig. 2, 11 is a transparent glass light-emitting tube made of inexpensive soda lime glass having a transmittance of 80% or more and a Na ₂ O of 10% or more at a wavelength of 320 to 340 nm. The transmittance of the arc tube using soda lime glass is as shown in Fig. 3, and a transmittance of 80% or more is obtained at a wavelength higher than 340 nm.

The arc tube 11 has a diameter D of 38 mm and a tube length L of 2367 mm, and has electrodes 121 and 122 at both ends. The electrodes 121 and 122 are formed by supporting the coil-shaped tungsten wires 14 with the conductive wires 131 and 132. The wires 131 and 132 penetrate the glass press-sealed portion 15. The wires 131, 132 are connected to pin-shaped contacts 171, 172 which are fixed to the respective plug connectors 161, 162 at opposite ends of the lamp.

Further, a rare gas such as argon (Ar) and a certain amount of mercury are sealed in the arc tube 11 at a low pressure of about 1 to 10 Torr. Further, the inner surface of the arc tube 11 is coated with an ultraviolet light-emitting phosphor 18 having a peak at 300 to 340 nm and having a peak of conversion efficiency as shown in FIG.

As such a phosphor 18, for example, NP-806 manufactured by Nichia Chemical Industry Co., Ltd. can be considered. The luminescent system is composed of LaPO ₄ (yttrium phosphate): Ce (铈).

Power is supplied from the electrodes 121 and 122 to the hot cathode low-pressure mercury lamp having the above configuration, and the characteristics of the spectral distribution as shown in Fig. 5 can be secured. In the spectral distribution, based on the light-emitting characteristics of the ultraviolet-emitting phosphor 18, it is found that the illuminance at 320 to 340 nm is further improved.

Figure 6 is a view showing the use and use of the phosphor of the present invention for the central portion (a), the sealed side (c), and the intermediate portion (b) of (a) and (c) of the ultraviolet discharge lamp of the present invention. A comparison result of the case where the illuminance at the measurement wavelength of 320 to 340 nm is different between the phosphors A and B will be described.

7 is an explanatory view for explaining a result of comparison between the case where the phosphor of the present invention is used and the illuminance using the different phosphors A and B.

The phosphor of the present invention has a composition of LaPO ₄ :Ce as described above, and the former phosphor A has a composition of YPO ₄ :Ce, and the former phosphor B has a composition of Ce(BaMgSr)Al ₁₁ O ₁₉ .

In the case of LaPO ₄ :Ce, the average illuminance at the lamp positions (a) to (c) is 0.457 (mW/cm ² ), and in the case of 100%, the phosphor A is 72.70%, and the phosphor B is 44.67%.

Therefore, in the case of coating a phosphor having a composition of LaPO ₄ :Ce on a hot cathode low-pressure mercury lamp comprising a transparent glass-emitting tube made of inexpensive soda lime glass containing 10% or more of Na ₂ O, coating and coating In the case of the phosphor B, the illuminance of 55% or more can be improved, and the illuminance of about 30% can be improved as compared with the case of applying the phosphor A.

In this embodiment, by irradiating the phosphor for ultraviolet light-emitting with the inner wall of the light-emitting tube made of inexpensive soda lime glass containing 10% or more of Na ₂ O, the illumination of 320 to 340 nm can be increased at least compared with the previous one. About 30%. The illuminance of 320 to 340 nm is improved. For example, when the liquid crystal panel is irradiated with ultraviolet rays in a state in which a liquid crystal material is mixed and a liquid crystal material which reacts with ultraviolet rays is caused to be polymerized, the ultraviolet ray reactive material can be efficiently polymerized.

In addition, when the illuminance is improved, when the same illuminance can be completed, the number of lamps can be reduced, which contributes to power saving.

In this embodiment, a general-purpose ultraviolet light-emitting type of hot cathode lamp is used, and an ultraviolet lamp which emits light with high efficiency at a wavelength of 320 to 340 nm can be realized. In addition, the liquid crystal panel in which the liquid crystal material and the ultraviolet ray reactive material are mixed or sealed is not required to be irradiated with extremely short wavelength, and the ultraviolet light irradiated from the ultraviolet discharge lamp of the present invention can be prevented from damaging the liquid crystal material. High-efficiency polymerization of UV-responsive materials.

Fig. 8 is an explanatory view for explaining another embodiment of the ultraviolet discharge lamp of the present invention. In this embodiment, the film thickness of the phosphor is changed, and FIG. 8 is an explanatory view for explaining the relationship between the contrast degree when the film thickness of the phosphor 18 is changed.

Here, a hot cathode low-pressure mercury lamp having an emission length of 2382.8±2.4 mm and an inner diameter of the arc tube 11 of 38±1.5 mm is used, and the contrast degree (%) when the film thickness of the phosphor 18 is changed from 1 to 49 μm. The measurement was carried out (320 nm band).

As shown in Fig. 8, when the film thickness of the phosphor 18 is in the range of 5 to 40 μm, a degree of contrast of about 90% or more can be obtained. Therefore, if the composition of the phosphor 18 to be used is LaPO ₄ :Ce and the phosphor 18 having a film thickness of 5 to 40 μm, a hot cathode low-pressure mercury lamp which achieves high illuminance can be realized.

In the present embodiment, the phosphor 18 having the composition of LaPO ₄ :Ce is used. By making the thickness of the phosphor 18 in the range of 5 to 40 μm, the illuminance at a wavelength of 320 to 340 nm can be improved.

Therefore, the illuminance at a wavelength of 320 to 340 nm can be increased. It is possible to obtain a lamp having a wavelength of 320 to 340 nm without increasing the number of lamps required for the illuminance rise portion, which contributes to cost reduction and is effective.

Further, the particle size of the phosphor 18 is preferably about 1 to 5 μm. This is mainly because the transmittance of light is reduced when it is smaller than 1 μm; in the case of being larger than 5 μm, mercury is liable to adhere and blacken between the particle diameters inside the arc tube, resulting in a decrease in the life of the lamp.

Further, the present invention is not limited to the foregoing embodiments. Since it can be fabricated by using a general ultraviolet light-emitting type hot cathode lamp, it can be applied to a 2500 mm required for illumination of a large-sized panel such as a next-generation liquid crystal substrate.

11. . . Luminous tube

14. . . Tungsten

15. . . Sealing part

18. . . Phosphor

121, 122. . . electrode

131, 132. . . wire

161, 162. . . Plug connector

171, 172. . . contact

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a view showing the configuration of a partial break display for explaining an embodiment relating to the ultraviolet discharge lamp of the present invention.

Figure 2 is a cross-sectional view taken along line I-I' of Figure 1.

Fig. 3 is an explanatory view for explaining the ultraviolet transmittance of general soda glass.

Fig. 4 is an explanatory view for explaining a light emission distribution of a phosphor used in the present invention.

Fig. 5 is an explanatory view for explaining the effects of the present invention.

Fig. 6 is an explanatory view for explaining the comparison of the illuminance at different positions of the present invention with the previous lamp.

Fig. 7 is an explanatory view for explaining the comparison of the present invention with the previous illuminance.

Fig. 8 is an explanatory view for explaining another embodiment relating to the ultraviolet discharge lamp of the present invention.

11. . . Luminous tube

14. . . Tungsten

15. . . Sealing part

18. . . Phosphor

121, 122. . . electrode

131, 132. . . wire

161, 162. . . Plug connector

171, 172. . . contact

Claims (3)

An ultraviolet discharge lamp comprising: a transparent glass light-emitting tube; an encapsulating inert gas and a mercury encapsulation sealed in the arc tube; and a pair of discharge electrodes disposed opposite to each other in the arc tube; and coated on the foregoing The inner wall of the arc tube is a phosphor having a conversion spectrum of 253.7 nm and having a peak of conversion efficiency at a wavelength of 300 to 340 nm; and the above-mentioned arc tube is made of soda lime glass containing 10% or more of sodium oxide in 100% of the base material. The film thickness of the phosphor is 5 to 40 μm. An ultraviolet discharge lamp characterized by comprising: an ultraviolet light-transmissive light-emitting tube made of soda lime glass; an inert gas for starting the seal and a mercury seal enclosed in the light-emitting tube; and a pair of opposite electrodes in the light-emitting tube; And a phosphor formed of LaPO ₄ :Ce as a matrix material on the inner surface of the light-emitting tube; the phosphor has a film thickness of 5 to 40 μm. The ultraviolet discharge lamp of claim 1 or 2, wherein the phosphor has a particle diameter of 1 to 5 μm.