TWI566017B - Ultraviolet radiation device - Google Patents

Description

Ultraviolet irradiation device

The embodiment of the present invention relates to an ultraviolet irradiation device used in a manufacturing process of a liquid crystal panel or the like.

In the manufacturing process of a liquid crystal panel, a light alignment engineer called a PSA (Polymer Sustained Alignment) project is generally performed in order to control the alignment. This project is a process in which a liquid crystal panel having a monomer of a liquid crystal and a photoreactive substance is irradiated with ultraviolet rays to polymerize a monomer to control the direction of the liquid crystal. For the irradiation of ultraviolet rays, as in Patent Document 1, an ultraviolet lamp is mainly used.

Here, the single-system absorption spectrum is the highest before and after 250 nm, and tends to be low toward a long wavelength. In order to polymerize a monomer, it is effective to irradiate ultraviolet rays before and after 250 nm having a high absorption spectrum. However, when ultraviolet rays of 300 nm or less are irradiated, the liquid crystal panel is affected, and the reliability of the liquid crystal panel may be lowered. Further, a light system having a longer wavelength than 380 nm has a possibility of causing heat to the liquid crystal panel.

Accordingly, in order to suppress damage to the liquid crystal panel, it is necessary to irradiate ultraviolet rays of 310 nm to 380 nm, particularly 320 nm to 350 nm, for polymerizing the monomers.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Laid-Open Patent Publication No. 2011-146363

The present invention provides an ultraviolet irradiation device capable of irradiating a strong ultraviolet ray at 310 nm to 380 nm, particularly 320 nm to 350 nm, as a problem to be solved.

In order to achieve the above-described problem, the ultraviolet irradiation device of the embodiment is an ultraviolet irradiation device that is irradiated onto a liquid crystal panel containing a photoreactive substance, and includes a fluorescent material having a phosphor containing LaPO ₄ having a peak wavelength of 310 nm to 340 nm. The first light source of the bulk layer and the second light source formed with a phosphor layer containing a phosphor of YPO ₄ having a peak wavelength of 340 nm to 360 nm.

Hereinafter, embodiments for carrying out the invention will be described.

The ultraviolet irradiation device of the embodiment will be described with reference to the drawings. Fig. 1 is a view for explaining an embodiment of an ultraviolet irradiation device.

Fig. 1 is a schematic view showing an ultraviolet irradiation device used for light alignment of a liquid crystal panel. The ultraviolet irradiation device is provided with a casing 1. The casing 1 is made of a metal or the like which is excellent in reflectivity against ultraviolet rays, and is incorporated therein. There is space in the department. The first light source and the second light source are disposed in the space system. The first light source is a tubular first fluorescent lamp 2, and the tube axes are arranged in parallel in a parallel connection. The second fluorescent lamp 3 having a tubular shape of the second light source is disposed between the first fluorescent lamps 2, and is disposed in parallel with each other in parallel with the tube axis.

The structure of the first fluorescent lamp 2 will be described with reference to Fig. 2 . As shown in FIG. 2, the first fluorescent lamp 2 is a hot cathode type fluorescent lamp (chemical lamp), and a glass tube 21 is provided as a main portion. The glass tube 21 is made of, for example, a glass made of ultraviolet-permeable quartz, and a rare gas in which mercury or a monomer such as argon, helium, neon or the like is mixed is sealed in the inside. Further, a phosphor layer 22 is formed on the inner wall surface. For both ends of the glass tube 21, for example, one of the pairs of wires 23 sealed with Kovar is held, and a filament 24 is held at the front end portion of the glass tube. The filament 24 is, for example, a spiral coil formed of tungsten, and a portion of the spiral portion is coated with a thermoelectron emitting material (emitter) having, for example, (Ba, Ca, Sr)O as a main component.

The second fluorescent lamp 3 has the same structure, but the phosphor layer is different for each fluorescent lamp. In the first fluorescent lamp 2, LaPO ₄ :Ce (铈-activated yttrium phosphate) is used as the phosphor layer 22, and in the second fluorescent lamp 3, YPO ₄ :Ce (yttrium activated phosphoric acid) is used as the phosphor layer. yttrium). LaPO ₄ :Ce and YPO ₄ :Ce are phosphors having an emission spectrum as shown in FIG. As can be seen from this figure, LaPO ₄ :Ce is 310 nm to 340 nm, specifically, has a peak wavelength near 337 nm, and YPO ₄ :Ce is between 340 nm and 360 nm, specifically, has a peak wavelength near 355 nm.

Further, the internal space of the casing 1 is such that the liquid crystal panel 4 is disposed opposite to the plurality of first fluorescent lamps 2 and the second fluorescent lamps 3. With this, the direct ultraviolet rays generated in the first fluorescent lamp 2 and the second fluorescent lamp 3 and the ultraviolet rays which are reflected between the inner surfaces of the casing 1 can be slightly uniformly irradiated onto the panel of the liquid crystal panel 4. surface. The liquid crystal panel 4 is a panel in which a liquid crystal and a photoreactive substance are contained in a single body. This single system has, for example, an absorption spectrum as indicated by the dotted line of FIG. In other words, the absorption spectrum is the highest at 260 nm, and gradually decreases toward the long wavelength side, and becomes almost zero at 350 nm.

Here, it is possible to alternately arrange 10 ultraviolet light irradiation devices (for the first fluorescent lamp 2 and the second fluorescent lamp 3) having a total length of about 1150 mm and a total length of 10 (a total of 20), such as a tube diameter of 15.5 mm, at a pitch of 50 mm. In the examples, 165 mA and 28 W were applied to each lamp to illuminate, and the emission spectrum of the liquid crystal panel 4 passing through the ultraviolet ray irradiation device was measured. The results are shown in Fig. 4. However, the machine used in the measurement was MSR-7000 manufactured by OPTO RESEACH Corp.

From Fig. 4, the radiation spectrum of the ultraviolet irradiation apparatus of this embodiment is found to be 310 nm to 380 nm, and the intensity of ultraviolet rays is strong, which is weaker than the short wavelength side of 310 nm and the long wavelength side of 380 nm. Especially in the range of 320 nm to 350 nm, the strength is strong. Accordingly, in this ultraviolet irradiation device, it is possible to effectively react the monomer while suppressing damage to the liquid crystal panel 4.

Next, the ultraviolet irradiation device (Example) of the above-described ultraviolet irradiation device (Comparative Example 1) similar to the fluorescent lamp in which only the phosphor layer of LaPO ₄ :Ce is mounted, and only the YPO ₄ :Ce are mounted. The same ultraviolet irradiation device (Comparative Example 2) of the fluorescent lamp of the phosphor layer was used, and the same ultraviolet irradiation device was used to mount only the fluorescent lamp in which the phosphor layers of LaPO ₄ :Ce and YPO ₄ :Ce were mixed, and the comparison was performed. Radiation spectrum test. The results are shown in Fig. 5. In Comparative Example 3, LaPO ₄ :Ce was 90%, YPO ₄ :Ce was 10%, Comparative Example 4 was LaPO ₄ :Ce was 80%, YPO ₄ :Ce was 20%, and Comparative Example 5 was LaPO ₄ :Ce was 70%. %, YPO ₄ : Ce is 30%.

From Fig. 5, in the examples, the relative intensity was high in the whole region of 310 nm to 380 nm, but the intensity of 340 nm to 380 nm in Comparative Example 1 was low, and the strength in Comparative Example 2 from 310 nm to 330 nm was low. In Comparative Examples 3 to 5, the weak point of Comparative Example 1 was 340 nm to 380 nm, but the 310 nm to 330 nm was greatly lowered. That is, the examples are compared with Comparative Examples 1 to 5, and it can be said that the strength at 310 nm to 380 nm is particularly high.

Here, LaPO _4: Ce, etc. where phosphor of the type of ultraviolet radiation, which is considered better life characteristics: Ce and YPO _4. As shown in Fig. 6, when the ultraviolet irradiation type fluorescent system is compared with the visible light irradiation type phosphor, the luminous intensity maintenance rate is clearly low. The visible light irradiation type fluorescent system used in Fig. 6 is generally used as a blue-based phosphor in a fluorescent lamp, and Sr ₂ P ₂ O ₇ :Eu (铕-activated yttrium phosphate). The reason why the luminous intensity maintenance rate is lowered is that the adhesion of mercury to the phosphor or the ultraviolet excitation function due to the collision of ions in the tube is lost.

In order to alleviate these reasons, a test for changing the film thickness of the phosphor layers of the first fluorescent lamp 2 and the second fluorescent lamp 3 was performed. The results are shown in Figures 7 to 9. Fig. 7 is a diagram showing LaPO ₄ :Ce, and Fig. 8 is a diagram showing the illuminance intensity retention rate when the thickness of the phosphor is changed in YPO ₄ :Ce. A graph showing the relationship between the film thickness of the light body and the luminous intensity maintenance rate. The luminous intensity of LaPO ₄ :Ce is UV-31 manufactured by Japan ORC Co., Ltd., and the luminous intensity of YPO ₄ :Ce is adjusted to 40 mm in the central portion of the lamp in the longitudinal direction of UV-35 manufactured by ORC Corporation of Japan. And to determine. That is, the luminous intensity value of LaPO ₄ :Ce shows the luminous intensity value of ultraviolet rays before and after 310 nm, and the luminous intensity value of YPO ₄ :Ce shows the luminous intensity value of ultraviolet rays before and after 350 nm.

From this result, even if LaPO ₄ :Ce and YPO ₄ :Ce are too small or too large, the tendency of the luminous intensity maintenance rate to fall is known. Specifically, in LaPO ₄ :Ce, the luminescence intensity retention rate becomes the maximum value before and after the film thickness = 10.5 μm, and in YPO ₄ :Ce, the luminescence intensity retention rate becomes maximum before and after the film thickness = 27.4 μm. value. In this case, in LaPO ₄ :Ce, the film thickness is set to 7.6 μm to 12.9 μm, and in YPO ₄ , the film thickness is preferably set to 23.4 μm to 29.0 μm.

However, for example, even the first fluorescent lamp 2 formed of a phosphor formed of Ca ₃ (PO ₄ ) ₂ : T1 (yttrium activated calcium phosphate) having a peak wavelength near 328 nm is combined, and has a peak formed near 360 nm. The same result was obtained for the second fluorescent lamp 3 of the phosphor formed by the wavelength of SrB ₄ O ₇ F:Eu (铕-activated lanthanum borate). That is, in the case of a lamp in which each of the phosphors is formed or a lamp in which the phosphors are mixed, a radiation spectrum having a high relative intensity at 310 nm to 380 nm can be obtained. Further, even if the first fluorescent lamp 2 formed of the phosphor layer 22 having a peak wavelength of (Ca, Zn) ₃ (PO ₄ ) ₂ : T1 (铊 activated calcium phosphate, zinc) is formed in the vicinity of 310 nm, and formed The same results were obtained for the second fluorescent lamp 3 having a phosphor layer of BaSi ₂ O ₅ :Pb and Ce (lead, ytterbium activated yttrium ytterbium) having a peak wavelength in the vicinity of 352 nm. In other words, the first fluorescent lamp 2 formed by combining the phosphor layers 22 having a peak wavelength of 310 nm to 340 nm and the second fluorescent lamp 3 having a phosphor layer having a peak wavelength of 340 nm to 360 nm are suppressed. At the same time as the damage of the liquid crystal panel 4, the monomer can be effectively reacted. However, when considering the environment, the lifetime of the phosphor, the matching of the wavelength of the phosphor, etc., the fluorescent system having a peak wavelength of 310 nm to 340 nm uses LaPO ₄ :Ce, and has a peak wavelength of 340 nm to 360 nm. The combination of YPO ₄ :Ce is optimal for the fluorescent system.

In the embodiment, the first fluorescent lamp 2, which is a phosphor having a peak wavelength of 310 nm to 340 nm and having a phosphor layer 22 made of LaPO ₄ :Ce, is disposed in parallel and arranged in parallel. The second fluorescent lamp 3, which is a phosphor having a peak wavelength of 340 nm to 360 nm and having a phosphor layer of YPO ₄ :Ce, is positioned between the first fluorescent lamps 2, and is arranged in parallel in parallel. In the liquid crystal panel 4 containing a monomer, 310 nm to 380 nm is strong, and 310 nm or less and 380 nm or more are light ultraviolet rays, and the liquid crystal panel 4 can be controlled and damaged. The monomer is allowed to react.

At this time, containing LaPO _4: The thickness of the phosphor layer to the phosphor 22 of Ce is set to 7.6μm ~ 12.9μm, and containing the YPO _4: The thickness of the phosphor layer formed between the phosphor of Ce When it is set to 23.4 μm to 29.0 μm, it can be used as a long-life lamp with excellent luminous intensity maintenance rate.

The present invention is not limited to the above embodiments, and various modifications can be made. For example, the first and second light sources are not limited to the hot cathode fluorescent lamp, but may be a cold cathode fluorescent lamp. In addition, an LED having a fluorescent layer, for example, an LED having a plastic film resin containing a phosphor may be disposed on a substrate. Mainly, it can be applied to a light source with a phosphor.

The embodiments of the present invention have been described, but the above embodiments are presented as examples and are not intended to limit the scope of the present invention. The above-described novel embodiments can be implemented in various other forms, and various omissions, substitutions and changes can be made without departing from the scope of the invention. The above embodiments and variations thereof are included in the scope and content of the present invention, and are included in the scope of the invention described in the claims.

1‧‧‧Shell

2‧‧‧1st light source

3‧‧‧2nd light source

4‧‧‧LCD panel

Fig. 1 is a view for explaining an embodiment of an ultraviolet irradiation device.

Fig. 2 is a view for explaining the fluorescent lamp of Fig. 1.

Fig. 3 is a view for explaining the radiation spectrum and the absorption spectrum of a single body of the phosphor formed in the first fluorescent lamp and the second fluorescent lamp of Fig. 1 .

Fig. 4 is a view for explaining the radiation spectrum obtained by the ultraviolet irradiation device of Fig. 1 and the absorption spectrum of the monomer.

Fig. 5 is a view for explaining the radiation spectra of the examples of Fig. 1 and Comparative Examples 1 to 5.

Fig. 6 is a view for explaining the luminous intensity maintenance ratio of the ultraviolet irradiation type phosphor (LaPO ₄ : Ce) and the visible light irradiation type phosphor (Sr ₂ P ₂ O ₇ : Eu).

FIG. 7 is a view for explaining the luminous intensity maintenance rate when the thickness of the phosphor of the fluorescent lamp having the phosphor layer formed of LaPO ₄ :Ce is changed.

FIG. 8 is a view for explaining the luminous intensity maintenance rate when the thickness of the phosphor of the fluorescent lamp having the phosphor layer formed of YPO ₄ :Ce is changed.

9 includes a system for LaPO _4: Ce fluorescent lamp formed by the phosphor layer, and includes ₄ YPO: Relationship retention rates of Ce to the fluorescent lamp phosphor layer with a thickness of phosphor emission intensity For the sake of illustration.

1‧‧‧Shell

2‧‧‧1st light source

3‧‧‧2nd light source

4‧‧‧LCD panel

Claims (4)

An ultraviolet irradiation device which is an ultraviolet irradiation device that irradiates a liquid crystal panel containing a photoreactive substance, and is characterized in that it comprises a first light source in which a phosphor layer containing a LaPO ₄ phosphor having a peak wavelength of 310 nm to 340 nm is formed, And a second light source formed with a phosphor layer of a YPO ₄ phosphor having a peak wavelength of 340 nm to 360 nm. The application ultraviolet irradiation apparatus described in item 1 of the patent, which contains the phosphor layer thickness based LaPO ₄ formed by the phosphor of the firefly 7.6μm ~ 12.9μm simultaneously, formed by containing the phosphor YPO ₄ The thickness of the photo-layer is 23.4 μm to 29.0 μm. An ultraviolet irradiation device which is an ultraviolet irradiation device that irradiates a liquid crystal panel containing a photoreactive substance, and is characterized in that: a first light source including a phosphor layer containing a phosphor having a peak wavelength of 310 nm to 340 nm is formed, and is formed There is a second light source containing a phosphor layer of a phosphor having a peak wavelength of 340 nm to 360 nm. The ultraviolet irradiation device according to any one of the first to third aspect, wherein the first light source and the second light source are tubular fluorescent lamps, and the first light source tube axis is parallel and parallel. In a plurality of positions, the second light source is disposed between the first light sources and arranged in parallel with the tube axis of the first light source in parallel.