JPH044555A - Discharge lamp device - Google Patents

Abstract

PURPOSE:To simplify the structure of a discharge lamp device and preclude influence of ultraviolet rays upon peripheral members of the discharge lamp by embodying a globe in a cylinder whose tip is blocked, retaining the rear end opening fixedly at the globe retaining part in the closed state, and covering lead supports protruding ahead of the globe retaining part and the discharge lamp with this globe. CONSTITUTION:An insulative base 20 is embodied in such a structure that a globe retaining part 40 made of ceramics is installed in a single piece with the front face of the base foundation 30 made of plastics, and a globe 50A is formed in a cylinder whose tip is blocked. An opening at tail of this globe is held fixedly at this globe retaining part 40 in closed condition, and lead supports 22, 24 protruding ahead of the part 40 and a discharge lamp 12 are covered with the globe 50A. This certainly shuts off emission of ultraviolet rays to outside the globe 50A, wherein ultraviolet rays are generated by the globe 50A for an ultraviolet rays shielding film together with light emission from the discharge lamp 12. As made of ceramics, the globe retaining part 40 blocking the open end of the globe is free of degradation even though it is exposed to ultraviolet rays. This allows simplification of the structure and preclude the peripheral members of the discharge lamp from being influenced by the ultraviolet rays.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a discharge lamp device, and more particularly to a discharge lamp device equipped with a glass tube for shielding ultraviolet rays surrounding the discharge lamp.

[Prior art and problems to be solved by the invention] In the recent automotive lamp industry, 9 has good luminous efficiency and color rendering properties,
In addition, discharge lamps are attracting attention because of their long lifespan and low λ and &N. However, for example, metal halide lamps, which are a type of discharge lamp.

Due to the sealing gas (mercury, iodide, Xe gas) in the discharge space, a large amount of ultraviolet rays are generated along with visible rays when light is emitted. Ultraviolet rays in the wavelength range of 240 to 290 nm destroy protein molecules;
Ultraviolet rays cause skin cancer, and the wavelength range is 360~
It is said that ultraviolet rays of 370 nm can destroy resin materials. As described above, since the light emitted from the discharge lamp contains ultraviolet rays that are harmful to the human body, there is a problem in that exposure to the irradiation over a long period of time is not good for health, and the resin members around the discharge lamp deteriorate quickly.

As a conventional technology for cutting ultraviolet rays, Japanese Patent Publication No. 6
No. 0-138845, which has a structure in which a glass tube 4 for cutting ultraviolet rays is arranged around a discharge lamp 2, as shown in FIG. Other conventional techniques include Japanese Patent Publication No. 62-53904, which is the seventh
As shown in the figure, a discharge lamp 2 is sealed inside a glass tube 6 for cutting off ultraviolet rays.

[Problem to be solved by the invention]

However, in the first prior art described above, the lead stay 5
Although it has a simple structure in which the glass tube 4 is supported through the
Since the glass tube 4 has the opening 4a, there is a problem in ensuring reliable shielding of ultraviolet rays.

Furthermore, in the second prior art, in order to reduce the adverse effects of the temperature and pressure inside the sealed glass tube 6 on the lighting of the discharge lamp 2, the glass tube 6 is filled with an inert gas such as N2 gas, or a vacuum is used. However, there are problems in that equipment for this is required and manufacturing is also troublesome.

The present invention has been made in view of the problems of the prior art,
The purpose is to have a simple structure that can reliably block UV rays.
Moreover, it is an object of the present invention to provide a discharge lamp device in which the surrounding members of the discharge lamp are not affected by ultraviolet rays.

[Means to solve the problem]

In order to achieve the above object, in the discharge lamp device according to the present invention, the discharge lamp is supported by a pair of lead supports protruding forward from an insulating base, and an ultraviolet shielding glove is arranged around the discharge lamp. In the discharge lamp device, the insulating base has a structure in which a ceramic globe holder is assembled and integrated with the front surface of the base base made of synthetic resin, and the globe has a cylindrical shape with a closed end. The rear end opening of the glove is fixedly held in a closed state by the glove holding part, and the lead support and discharge lamp protruding forward of the glove holding part are completely covered by the glove.

[Effect]

The opening end of the globe is fixedly held by an insulating-based globe holder, and the area around the discharge lamp is completely covered by a UV-shielding globe, and this UV-shielding film is used to generate light as the discharge lamp emits light. Reliably blocks ultraviolet rays from exiting the glove. In addition, the glove holder that closes the opening end of the glove is made of ceramic and will not deteriorate even when exposed to ultraviolet rays.

〔Example〕

Next, embodiments of the present invention will be described based on the drawings.

1 to 3 show a first embodiment of the present invention,
FIG. 1 is a partially cutaway perspective view of the discharge lamp device;
Figure 2 is an exploded perspective view of the insulating base, which is the main part of the lamp device, and Figure 3 is a longitudinal sectional view of the lamp device inserted into a reflector and used as a bulb for an automobile headlamp. be.

In these figures, the discharge lamp device 10 includes a discharge lamp 12 which is a light emitting part, lead supports 22 and 24 which protrude from an insulating base 20 and support the discharge lamp 12, and which are fixedly held on an insulating base 2o. It mainly consists of an ultraviolet shielding glove 50A that completely covers the discharge lamp 12.

The discharge lamp 12 has an ellipsoidal sealed glass bulb 1 formed by pinching both ends of a quartz glass tube to form a discharge space.
With a structure in which pinch parts 14 and 14 are formed at both ends of 3,
The glass bulb 13 is filled with a starting rare gas, mercury, and metal halide. Further, a discharge electrode 15.15 made of tungsten is disposed facing each other in the discharge space, and the discharge electrode 15.15 is connected to a molybdenum foil 16 sealed to the pinch part 14. A lead wire 18° 18 connected to the molybdenum foil 16 is led out from the frame. The rear end lead wire 18 is attached to a metal support 19 fixed to a lead support 22 that projects forward of the insulating base 20, and the distal end lead wire 18 is attached to a lead support 24 that projects forward of the insulating base 20. Each is connected to the bent part of the tip by spot welding,
The discharge lamp 12 has a structure in which both ends are supported by lead supports 22.24 via lead wires 18.18.

The insulating base 20 has an integrated structure in which a disk-shaped globe holding part 40 made of ceramic and having a diameter slightly smaller than the base base 3o is bonded to a disk-shaped base base 30 made of synthetic resin.

A shallow concave surface 31 is formed on the front surface of the base 30, and the glove holding section 40 is engaged with the concave surface 31. This glove holding part 40 is a UV shielding glove 50A which will be described later.
It is a part that closes the rear end opening and is directly exposed to the ultraviolet rays generated when the discharge lamp 12 emits light, and is made of ceramic that is unlikely to be deteriorated by ultraviolet rays. Furthermore, four ventilation holes 26 are formed in the insulating base 2o, which are communication holes communicating from the front side to the sides. At the periphery of the bulb insertion hole 9 (see Fig. 2) of the reflector 8,
A notch 9a is formed to open the side opening of the ventilation hole 26 of the insulating base 20 in the front region of the reflector. That is, the rear end opening of the ultraviolet ray shielding glove 50A is sealed in the glove holding part 40, and the glove 50A
Although the inside is sealed, the inside of the glove 50A is opened to the front area of the reflector 8 through the ventilation hole 26, thereby ensuring ventilation inside and outside the glove. The arrows in FIG. 3 indicate the convection that occurs between the front area of the reflector 8 and the interior of the globe 50A via the ventilation hole 26. This prevents the performance of the discharge lamp 12 from deteriorating or shortening its life due to the inside of the globe 50A being kept at a high temperature. Note that this ventilation hole 26 is connected to a groove 36 on the base base 30 side.
and a hole 46 on the glove holding part 40 side. Further, the outer edge 32 of the base 30 is attached to the light reflecting surface (
It acts as a focusing ring for positioning in the front, rear, left and right directions (front, rear, left and right when looking at the reflector from the front) with respect to the paraboloid (paraboloid) 8a, and the front surface of the outer edge portion 32 has contact reference surfaces at three equally spaced locations in the circumferential direction. A raised portion 33 is formed. Further, this outer edge portion 32 is formed with a circumferential positioning notch 34 that engages with an engagement protrusion (not shown) on the reflector side when the lamp device 10 is inserted into the bulb insertion hole 9. ing. A groove 3 forming a part of the ventilation hole 26 from near the center of the base to the side edge of the base 30 is formed on the front surface of the base 30.
6 is formed. Further, a lead support 22 which is insert-molded in the base portion 30 projects from the front. - On the other hand, the ceramic base holding part 40 is a disc-shaped body with an outer flange, and has a central disc part 42 protruding from the front surface that matches the inner diameter of the opening end of the glove. occlude the opening. Further, a ring-shaped groove 44 is formed around the second central disc part 42, and the glove opening edge engages with this groove 44, and the adhesive loaded in the engagement part forms the glove 50A. The inside is completely sealed. Also, the base base 30
And the glove holding part 40 has a lead support 24.2.
Holes 38, 48, 49 are formed for penetrating the lead support 24, and the lead support 24 is inserted into the ceramic discharge prevention insulating cylinder 47, and is fitted into the hole 38, 48 and fixed with adhesive. . Reference numerals 22a and 24a designate the protruding portions 1 of the lead supports 22, 24 toward the rear of the base 30, which are protected by a synthetic resin cylindrical body 28 adhesively fixed to the base 30.

The ultraviolet shielding glove 50A has a spherical front end,
It has a cylindrical shape with an open rear end.

The rear end opening is fitted into the ceramic globe holder 40 of the insulating base 20 and fixed with adhesive, so that the lead support 22, 24 and the discharge lamp 12 are completely covered by the globe 50A. The ultraviolet shielding globe 50A has a structure in which the outer peripheral surface of a glass tube with a closed end 51 is coated with an ultraviolet shielding film 52 made of Zn○, and the ultraviolet shielding film 52 covering the discharge lamp 12 is generated at the same time as the discharge lamp emits light. Glove 5 absorbs ultraviolet rays and allows only visible light to be cut off.
It is designed to emit outside of 0A.

To form the ultraviolet shielding film 52, fine particles of Zn◯ are dispersed in an inorganic binder (concentration 20 to 30%), and this is applied to the glove surface by an appropriate method such as dipping, spraying, or vapor deposition. In order to set the transmittance of ultraviolet rays in the wavelength range shorter than 370 nm to O, a film thickness of 1.6 μm or more is required, and from the viewpoint of preventing peeling, a film thickness of 5 μm or less is desirable. In addition, the wavelength range of ultraviolet rays that can be cut varies depending on the temperature around the glove (when the temperature gets higher, the wavelength range that is cut shifts to the longer wavelength side), so the film thickness must be such that it can at least block ultraviolet rays in the wavelength range of 370 to 380 nm or less. adjust.

Note that the film thickness can be adjusted by changing the dipping pulling speed, or by changing the number of times of coating and the number of times of vapor deposition.

In the above embodiment, the ultraviolet shielding film 52 is made of Zn○, but it may be made of a compound having an ultraviolet absorbing effect such as TiO2, CaO, Fe2O3, etc., although the ultraviolet absorbing effect is inferior to that of ZnO.

FIG. 4 shows the main part of a second embodiment of the present invention, showing an enlarged cross section of an ultraviolet shielding globe arranged around a discharge lamp.

In this figure, the reference numeral 50B is a glove for shielding ultraviolet rays, and the ultraviolet ray shielding film 54 formed on the outer peripheral surface of the glass tube 51 is made of TiO2, SiO2゜MgF, Taz○5.
It is composed of a dielectric multilayer film made of compounds each having a different refractive index and having an ultraviolet absorbing effect. In the figure, the ultraviolet shielding film 54 is composed of a dielectric multilayer film in which Si02 layers 54a and TiO2 layers 54b are alternately laminated, and ultraviolet rays in the wavelength range of 360 nm or less are
The ultraviolet rays in the wavelength range of 360 to 380 nm are absorbed by the Ti02 layer and the Ti02 layer, respectively, and are canceled out by the reflected light at the interface between each dielectric layer. Also, SiO2
It may be a structure in which layers and Ta206 layers are alternately laminated, and in this case, ultraviolet rays in the wavelength range of 300 nm or less are absorbed by each dielectric layer, and ultraviolet rays in the wavelength range of 300 to 380 nm are absorbed.
The ultraviolet rays are canceled out by the reflected light at the interface between each dielectric layer. Furthermore, a dielectric multilayer structure in which Ti02 layers and MgF layers are alternately laminated may be used.

That is, the film thickness d of each dielectric layer (for example, 54a and 54b)
is d = n / 4λ (λ: wavelength you want to cancel, n
: refractive index of the dielectric material), and by setting this film thickness d to an appropriate value, the phase of the reflected light at the interface between each dielectric layer is reversed with respect to the phase of the incident light, and this reflected light is The light acts to cancel out ultraviolet rays of wavelength λ.

Further, the thickness of the dielectric layer is increased as the distance from the glass bulb 13, which is the light emitting part, increases, thereby preventing the wavelength range of the ultraviolet rays to be cut from changing. That is, the wavelength range of ultraviolet light absorbed by the ultraviolet shielding film shifts toward shorter wavelengths in proportion to the angle of incidence of light on the film. Therefore, if the thickness t of the ultraviolet shielding film (dielectric multilayer film) 54 is made uniform in the longitudinal direction of the glove, there is a problem that the ultraviolet absorption effect at the front and rear ends of the glove is poor. More specifically, compared to the central region of the globe that directly faces the glass bulb 13 and where the incident angle of light is close to 0,
The incident angle θ of light on the ultraviolet shielding film is large, and the ultraviolet ray cutting effect is inferior (the ultraviolet wavelength range to be cut shifts to the shorter wavelength side).

Therefore, as shown in FIG. 5, the thickness of the ultraviolet shielding film 54 is increased by increasing the diameter of the front and rear ends of the glove and the thickness of each dielectric layer. They are adjusted to be approximately the same in the longitudinal direction.

Note that in the two embodiments described above, the ultraviolet shielding film 52.5
Although the structure in which the UV shielding films 52 and 54 are formed on the outside of the glove has been described, the ultraviolet shielding films 52 and 54 may be formed on the inside of the glove, or may be formed on both the outside and inside of the glove.

Furthermore, when the discharge lamp device according to the present invention is used as a light source for an automobile headlamp, a light-shielding coating called a black top that blocks direct light from the discharge lamp is formed at the tip of the closed-end glass tube, Ultraviolet shielding films 52 and 54 may be formed in the glass tube area except for this light-shielding coating.

Further, the ultraviolet shielding glove in the above embodiment had a structure in which the glass tube 51 was coated with an ultraviolet shielding film 52, 54, but the glove was made of soda glass, hard glass, alumina silicate glass, etc., which have an ultraviolet ray shielding effect. It may be configured.

〔Effect of the invention〕

As is clear from the above description, according to the discharge lamp device according to the present invention, the opening end of the globe is fixedly held by the globe holding part of the insulating base, and the circumference of the discharge lamp is surrounded by the globe for shielding ultraviolet rays. It is completely covered, and the UV-shielding film globe reliably blocks the UV rays generated when the discharge lamp emits light from exiting the globe, so there is no problem with UV rays being generated when the lamp is turned on, unlike in conventional discharge lamp devices. It never happens. Furthermore, the insulating-based glove holder that closes the end of the globe opening is made of ceramic and does not change in quality even when exposed to ultraviolet rays, thereby improving the durability of the discharge lamp device.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway perspective view of the discharge lamp device;
Fig. 2 is an exploded perspective view of the insulating base, which is the main part of the lamp device, and Fig. 3 is a longitudinal sectional view of the lamp device inserted into a reflector and used as a bulb for an automobile headlamp. FIG. 4 is an enlarged cross-sectional view of a UV-shielding glove which is a main part of the second embodiment of the present invention, FIG. 5 is a cross-sectional view illustrating means for adjusting the thickness of the UV-shielding film, and FIGS.
Each figure is a perspective view of the prior art. DESCRIPTION OF SYMBOLS 10... Discharge lamp device, 12... Discharge lamp, 20... Insulating base, 22.24... Lead support, 30... Base base, 40... Glove holding part, 42...・Central disc part of the glove holding part that closes the opening end of the glove, 50A, 50B...Glove for ultraviolet shielding, 52.
...Ultraviolet shielding film, 54...Dielectric multilayer film that is an ultraviolet shielding film.

Claims (1)

[Claims] (1) In a discharge lamp device in which a discharge lamp is supported by a pair of lead supports protruding forward from an insulating base and an ultraviolet shielding glove is arranged around the discharge lamp, the insulating base is made of synthetic resin. has a structure in which a ceramic glove holder is assembled and integrated on the front surface of the base, and the glove has a cylindrical shape with a closed end, and the opening at the rear end of the glove is closed by the glove holder. 1. A discharge lamp device characterized in that a lead support and a discharge lamp that are fixedly held in a fixed position and project forward of a glove holding part and a discharge lamp are completely covered by a glove.