JPH024100B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the structure of a forced cooling type ultra-high pressure mercury lamp used for exposing the fluorescent surface of a color cathode ray tube.

Conventionally, as a light source for exposing the fluorescent surface of a color cathode ray tube, as shown in FIG. A high-pressure mercury lamp 2 was installed and used. When in use, this lamp generates intense heat rays in addition to ultraviolet light, near ultraviolet light, and visible light due to transposition emission of mercury vapor. High-pressure air is blown into the forced flow space 1 in the lamp house 1.
3 and then drained from the drain 7. As shown in FIG. 2, this forced cooling type ultra-high pressure mercury lamp 2 has mercury 9 sealed in a quartz glass pipe 3, an electrode 8 provided thereon, and a high voltage (approximately 0.5 to 1.5 KV) applied between electrode terminals 6. It operates depending on the situation.
For exposure of the fluorescent surface of a color cathode ray tube, the near-ultraviolet emission of 3650 Å from the transition emission of mercury vapor is useful. Conventionally, in order to shorten the exposure time of the fluorescent surface, a reflector 10 was installed so that the axis was concentric with the tube wall of the lamp as shown in FIG. Attempts were made to increase the intensity of the exposed lines by reversing the beam. If a reflector 10 with sufficient reflectance is used, it is possible to increase the intensity of the exposed rays to about twice as much in the initial stage. If the surface becomes oxidized or impurities in the high-pressure air are burned onto the mirror surface, the reflectance of the mirror 10 decreases, which not only reduces the intensity of the exposure light beams, but also reduces the uniformity of the light distribution of the exposure light beams. This is a fatal defect for the exposure process of the fluorescent surface of color cathode ray tubes, which requires highly accurate light distribution.
The positional relationship between the lamp and the reflector is also important, and if this setting is not accurate, it may become a double light source, which is extremely difficult to use as a light source for exposing the fluorescent surface of a color cathode ray tube, where positional accuracy is important. This will be undesirable. In order to eliminate such drawbacks of the reflector, a metal such as Al (aluminum) or Ag (silver), for example, is directly applied to one side of the outer circumferential surface of the quartz glass pipe 3 of the forced cooling type ultra-high pressure mercury lamp 2 as shown in Fig. 4. An attempt is made to form a vapor deposited film 11. With this type of direct reflecting mirror, the aforementioned problems of the reflection characteristics of the reflecting mirror changing over time and the problem of the positional relationship between the lamp and the reflecting mirror are all solved, and exposure lines with good intensity can be obtained. A new and serious problem has arisen. In other words, the heat rays emitted from the inside are reflected back into the part where the metal vapor-deposited film 11 is attached, so the temperature of the lamp in this part rises abnormally, resulting in damage to the lamp or damage to the quartz glass.・Pipe 3
This causes serious damage, such as the occurrence of devitrification, which significantly shortens the life of the lamp, and the devitrification, which impedes the light distribution characteristics of the exposed lines.

This invention was made in order to solve the above-mentioned problems, and it is possible to sufficiently increase the exposure light intensity without shortening the lamp life or deteriorating the light distribution characteristics due to devitrification. The purpose is to provide a cooled ultra-high pressure mercury lamp.

An embodiment of the present invention will be described below with reference to FIG. 4, which shows a conventional forced cooling type ultra-high pressure mercury lamp 2 on which a metal vapor deposited film 11 is formed.

In this invention, cerium oxide (CeO ₂ ) and magnesium fluoride (MgF ₂ ) are used instead of the metal vapor deposited film 11.
A multilayer film of uniform thickness is formed in close contact with the outer peripheral surface of the quartz glass pipe 3. Such an optical film 12 utilizes the interference phenomenon of light and is known in principle as a cold mirror, and if the film thickness of each deposited layer is sufficiently controlled, it can achieve a reflectance in the near ultraviolet region of 3650 Å. 70-90%, infrared reflectance 10-20
% selective optical film 12 can be obtained. This kind of selective optical film 12 is made of conventional Al (aluminum).
If it is used in place of the vapor deposited film 11 of metal such as Ag (silver), most of the heat rays radiated from inside the lamp will not be reflected back inside, and most of the near ultraviolet light of 3650 Å will be reflected again. Although the intensity of the exposed lines is increased by being reflected to the side, there are no problems such as shortened lamp life due to lamp temperature rises or problems with the light distribution characteristics of the exposed lines due to devitrification that are obstructed by conventional lamps. .

Although the forcibly cooled ultra-high pressure mercury lamp using air as a refrigerant has been described above, this invention is not limited to this, and the present invention is not limited to this.
If a combination of these is selected, it can also be applied to forced cooling ultra-high pressure mercury lamps using water as a refrigerant.

As described above, according to the present invention, of the outer circumferential surface of the quartz glass pipe in the mercury lamp installed in the forced flow space of the refrigerant in the lamp house, approximately half the circumferential surface on the side that does not emit the exposure light beam.
A selective optical film made of a multilayer film of cerium oxide and magnesium fluoride that transmits most of the heat rays and reflects most of the near-ultraviolet light is formed in close contact with the film, so that the forced-flowing refrigerant cools the entire lamp. Combined with the effect of suppressing the temperature rise caused by the reflection of heat rays into the interior of the lamp, thermal damage to the lamp and devitrification of the quartz glass pipe can be suppressed as much as possible. Therefore, it is possible to increase the reflection efficiency of near-ultraviolet light and sufficiently increase the intensity of the exposure light while sufficiently suppressing the reduction in lamp life and the deterioration of the light distribution characteristics of the exposure light due to the addition of the film. It has the effect of being able to do it.

[Brief explanation of drawings]

Figure 1 is a side view showing a conventional lamp house;
FIG. 2 is a side view showing a conventional forced cooling type, FIG. 3 is a side view showing a conventional reflective type, and FIG. 4 is a side view showing an embodiment of the present invention. In the figure, 3 is a quartz glass pipe, and 12 is a selective optical film. In addition, in the figures, the same reference numerals indicate the same or corresponding parts.

[Claims]

1 Lamp total length is 120mm or less, power consumption is 1.5W
A compact fluorescent lamp as described below, characterized in that the electrode is of thermionic emission type. 2. A compact fluorescent light according to claim 1, which is filled with a gas selected from argon, krypton or neon at a pressure of 6 to 50 torr. 3. The small-sized fluorescent light according to claim 1, wherein a three-wavelength type phosphor having high optical output at wavelengths of approximately 440 nm, 550 nm, and 610 nm is coated on the inner surface of a glass enclosure.