KR101934145B1

KR101934145B1 - Long-arc type discharge lamp and light irradiation apparatus

Info

Publication number: KR101934145B1
Application number: KR1020150072737A
Authority: KR
Inventors: 히데아키 야규
Original assignee: 우시오덴키 가부시키가이샤
Priority date: 2014-07-08
Filing date: 2015-05-26
Publication date: 2018-12-31
Also published as: JP2016018646A; KR20160006103A; CN105261547B; TWI638381B; JP5915976B2; TW201603110A; CN105261547A

Abstract

A long arc type discharge lamp in which a metal is sealed as a light emitting material in a light emitting tube and a strip-shaped reflective film is formed on an outer surface of the light emitting tube; and a light irradiation device using the short arc type discharge lamp, Even when high power and low power are frequently switched and turned on, the reflective film does not peel off and peels off. Wherein the OH group content of the tube wall of the arc tube is 50 ppm to 300 ppm and the OH group content of the reflective film is 100 ppm or more.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a long arc type discharge lamp,

The present invention relates to a long arc type discharge lamp and a light irradiation apparatus, and more particularly to a long arc type discharge lamp having a reflection film on the outer surface of an arc tube and a light irradiation apparatus having the same.

Background Art [0002] Conventionally, in the printing industry and the electronic industry, there has been known an ultraviolet light source of an apparatus for photochemical reaction used for drying of ink, paint, and curing resin, or an exposure used for exposing a semiconductor substrate or a liquid crystal substrate for a liquid crystal display As the ultraviolet light source of the apparatus, a long arc type discharge lamp such as a mercury lamp or a metal halide lamp is used.

The long arc type discharge lamp 1 used in the conventional light irradiation apparatus will be described with reference to Fig.

An encapsulating portion 3 is formed at both ends of the arc tube 2 and a pair of electrodes 4 and 4 are arranged in the arc tube 2. [

The rear end portion 4a of the electrode 4 is cut into a substantially prismatic shape so that the upper and lower portions thereof are flat.

A flat spacer glass 5 made of quartz glass is buried in the sealing portion 3 and a pair of metal foils 6a and 6b are formed on the upper and lower surfaces thereof so as to sandwich the spacer glass 5 therebetween. And the outer leads 8 are connected to the rear ends of the metal foils 6a and 6b.

A glass holding cylinder 7 is disposed in the sealing portion 3 and the electrode 4 is inserted into the holding cylinder 7 so that the electrode 4 is supported .

When the lamp 1 is fitted in the light irradiation device, the opening 9 is provided on the rear end of the sealing part 3 so that the opening of the lamp 1 Respectively.

On the outer surface of the arc tube 2, a strip-shaped reflective film 10 is formed over the entire length of the light emitting tube 2, and the light directed upward above the arc tube 2 is reflected to irradiate the irradiated object below will be.

From the viewpoint of heat resistance, the reflection film 10 is mainly composed of silica particles, and is composed of alumina particles or a mixture of silica particles and alumina particles. In the outer surface of the arc tube 2, Like shape.

In the long arc-type discharge lamp of the above-described configuration, metal such as mercury, iron or gallium is sealed in the arc tube 2 in order to radiate ultraviolet rays well.

The structure of the light irradiation device using such a long arc type discharge lamp is known from Japanese Patent Application Laid-Open No. 2008-130302 (Patent Document 1) and Japanese Patent Application Laid-Open No. 2012-198997 (Patent Document 2) The structure is shown in Fig.

Fig. 3 (A) is an explanatory diagram of a state in which the reflection mirror is opened. Fig.

Fig. 3 (B) is an explanatory diagram of a state in which the reflection mirror is closed;

The light irradiation device 20 has a tubular reflection mirror 21 surrounding the metal halide lamp 1 and has a reflection surface 22 made of a dielectric multilayer film or the like on the inner surface thereof.

The reflecting mirror 21 has a top opening 21a and a front opening 21b and is openable and closable and a top opening 21a is disposed corresponding to the cooling air exhaust opening 23 . 3 (A), the front opening 21b is opened. In the standby lighting mode such as the replacement of the processed object, as shown in Fig. 3 (B), in the normal lighting mode in which ultraviolet rays are irradiated on the object, , The reflecting mirror 20 is rotated to close the front opening 21b. Further, in the standby lighting mode, the input power to the lamp is lowered from the viewpoint of the sex power.

3 (A), the cooling wind flows from below the reflecting mirror 21, passes through the periphery of the lamp 1 to cool it, passes through the top opening 21a through the exhaust opening 23 Out.

3 (B), the lamp is turned on at a lower power than the rated power, and the front opening 21b of the reflecting mirror 21 is closed at this time, 21 are heated. In order to protect the dielectric multilayer film constituting the reflecting surface 22 of the reflecting mirror 21, it is necessary to cool the dielectric multilayer film, so that the cooling wind is not stopped and the ventilation is maintained.

As described above, in the production line as much as possible, the power consumption is required. In the work non-treatment period such as the work exchange, the discharge lamp is lighted at a sufficiently low power (while being maintained in the lighting state of the discharge lamp, Standby lighting mode is adopted.

As a result, the discharge lamp is in a state in which the power value is greatly changed in a short period of time of several tens seconds, which is referred to as a processing period and a non-processing period of the work, and the high temperature state and the low temperature state are changed in a short cycle.

Here, for example, the power per unit length at the effective light emission length is 280 W / cm at normal lighting and 80 W / cm at standby lighting (for example, power at normal lighting and power at standby lighting / cm.

As described above, the high power and the low power are frequently changed, and the electric power is conventionally increased to increase the level difference, so that the thermal stress becomes more conspicuous at the interface between the light-emitting tube and the reflective film. With the lapse of the lighting time of the discharge lamp, The reflective film is peeled off.

Japanese Patent Application Laid-Open No. 2008-130302 Japanese Patent Application Laid-Open No. 12-199997

SUMMARY OF THE INVENTION In view of the problems of the prior art described above, the present invention has been made in view of the above problems in the prior art, in which a pair of electrodes are disposed opposite to each other in a light emitting tube, a metal is sealed as a light emitting material, Arc type discharge lamp in which the reflection film is peeled off and does not fall even when the discharge lamp is frequently turned on by changing the high power and the low power in the long arc type discharge lamp in which the reflection film of the long arc type discharge lamp is formed over the entire light emission length .

It is another object of the present invention to provide a light irradiation apparatus using a long arc type discharge lamp and a method of using the long arc type discharge lamp without using the light reflection film radiated toward the opening of the reflection mirror uselessly, And it is an object of the present invention to provide a highly reliable light irradiation apparatus that does not detach and peel off the reflective film even if the lamp is frequently turned on by switching between high power and low power.

In order to solve the above problems, the long arc discharge lamp according to the present invention is characterized in that the OH group content of the tube wall of the arc tube is 50 ppm to 300 ppm, and the OH group content of the reflective film is 100 ppm or more.

The light irradiating apparatus according to the present invention is characterized in that the long arc type discharge lamp is used and a reflecting surface surrounding the discharge lamp is provided and a reflecting mirror having a trough- And a control unit.

According to the long arc type discharge lamp of the present invention, even when the discharge lamp is frequently turned on with high power and low power, OH groups are contained in both the reflective film and the arc tube, A strong adhesion can be obtained by dehydration condensation reaction, so that the film can be lighted for a long time without peeling or cracking even in a severe lighting condition.

In addition, since the OH group of the light emitting tube is 50 ppm or more, sufficient OH groups to be bonded to the reflective film are sufficiently present, and sufficient bonding with the reflective film is obtained, and since this is 300 ppm or less, the amount of OH released from the light emitting tube into the discharge space becomes too large It is possible to avoid the phenomenon called electrode oxidation.

Since the OH group content of the reflective film is 100 ppm or more, the dehydration condensation reaction between the OH groups of the light emitting tube and the reflective film contributes to bonding of the silica particles to each other, making the reflective film itself difficult to peel off.

Further, according to the light irradiation device including the long arc type discharge lamp and the cylindrical reflection mirror, the light radiated from the discharge lamp toward the opening is not nullified while maintaining the cooling structure of the mirror opening, It is possible to provide a light irradiation apparatus having high reliability even when the discharge lamp is frequently turned on and off with high power and low power so that the reflection film does not peel off or peel off.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a partial cross-sectional view of an arc tube in a long arc type discharge lamp of the present invention. Fig.
2 is a sectional view of a conventional long arc type discharge lamp.
3 is an overall sectional view of a conventional light irradiation apparatus.

The whole structure of the long arc type discharge lamp in the present invention is the same as that shown in Fig. 2, and the metal enclosed in the arc tube 2 as a light emitting material is, for example, mercury (Hg) , Gallium (Ga), and the like, or a mixture of two or more thereof.

Further, the reflective film 10 is composed mainly of silica particles, and preferably comprises silica particles in a proportion of more than 50%.

As shown in Fig. 1 (A), the silica particles constituting the reflection film 10 contain OH groups. As a means for containing an OH group, for example, a method of producing silica by a wet method such as a precipitation method, a gel method or a sol-gel method can be suitably employed. Of course, even in the silica produced by the dry method, for example, by using a silica-based alkoxide solution as a binder, it becomes possible to form a reflective film having an OH group. The shape and diameter of the fine particles are not particularly specified as long as they function as the reflective layer, but the reflection mechanism of the fine-grained film is preferably reflected on the surface of the individual fine particles, For example, the shape of the fine silica particles is a shape such as a sphere shape or a flat shape, and the average particle diameter is preferably about 0.1 to 10 mu m.

The quartz glass constituting the arc tube 2 also contains an OH group. The OH group is contained by, for example, a method of melting quartz powder using an oxyhydrogen flame (flame-quartz quartz) or by heating the valve at a high temperature in a state exposed to the atmosphere.

1B, the OH group of the light emitting tube 2 and the OH group of the fine silica particles constituting the reflective film 10 are dehydrated and condensed as shown in Fig. 1 (B) And the adhesion of the reflective film 10 to the arc tube 2 can be increased.

The OH group content of the arc tube 2 is preferably 50 to 300 ppm. When it is 50 ppm or less, the OH groups to be bonded are reduced, and the adhesion strength of the reflective film 10 is lowered. On the other hand, if it exceeds 300 ppm, the amount of OH released from the arc tube 2 into the discharge space increases, and oxidation of the tungsten electrode in the discharge space occurs, thereby promoting the melting. As a result, tungsten adheres to the light-emitting tube, resulting in lowering the illuminance.

The content of OH groups in the reflective film 10 is preferably as large as possible, and these can increase the bonding force with the arc tube 2 and increase the bonding force between the fine particles.

As described above, according to the discharge lamp of the short arc type related to the present invention, the OH groups are contained in both the reflection film and the light-emitting tube, whereby OH groups are dehydrated and condensed at the interface, and stronger adhesion is obtained.

An experiment was conducted to demonstrate the effect of the present invention.

(Distance between a pair of electrodes) of 250 mm, an inner diameter of an arc tube of 22 mm, and an outer diameter of 26 mm using a reflection film and an arc tube differing in OH group content from each other. In each of the arc tubes, the enclosed amount of mercury was 58 mg, A long arc type mercury lamp in which 2.5 mg of mercury and 1 kPa of argon were enclosed and a slurry containing fine silica particles in the form of scales was applied as a reflective film material to a reflective film having a width of 10 mm in the longitudinal direction of the lamp, Then,

These lamps were turned on for 1000 h in a lighting mode in which the input was alternately changed between 80 W and 280 W per 1 cm arc length for 30 seconds, and the appearance of the reflective film was observed.

The results are shown in the following table.

As can be seen from the above table, when the OH groups of the light-emitting tube and the reflective film were small, the reflective film peeled off under severe lighting conditions in which the bonding force was weak, On the other hand, in the case of containing a large amount of OH groups, peeling of the reflective film did not occur even in severe lighting conditions.

In Comparative Example 3, peeling of the film did not occur, but the amount of OH groups contained in the arc tube was so large that the arc of the arc tube occurred, resulting in a remarkable reduction in the illuminance.

1: long arc type discharge lamp 2: arc tube
3: sealing part 4: electrode
5: spacer glass 6a, 6b: metal foil
7: retaining cylinder 8: outer lead
9: mouthpiece 10: reflective membrane
20: light irradiation device 21: reflection mirror
21a: Top opening 21b: Front opening
22: Reflecting surface 23: Cooling air exhaust port

Claims

A pair of electrodes are disposed opposite to each other in an elongated quartz glass bulb, a metal is sealed as a luminescent material,
In a long arc type discharge lamp in which a strip-shaped reflective film mainly composed of silica particles is formed on the outer surface of the arc tube over the entire emission length,
The content of OH groups in the wall of the arc tube is 50 ppm to 300 ppm,
Wherein an OH group content of the reflective film is 100 ppm or more.

A long arc type discharge lamp according to claim 1,
And a trough-shaped reflection mirror having a reflecting surface surrounding the long arc-type discharge lamp and having an opening corresponding to an upper portion of the long arc-type discharge lamp.