JPH0426047A - Noble gas discharge lamp - Google Patents

Abstract

PURPOSE:To reduce temperature dependency by using xenon or mixed gas consisting of xenon and inert gas an noble gas that radiates ultra-violet ray. CONSTITUTION: A discharge lamp 1 has a bulb 2 inside of which a thin and long discharge space 3 is formed. The bulb 2 consisting of a glass tube forms a needle shape of, for example, 2.5mm in outer diameter, 1.5mm in inner diameter, and 60mm in overall length approximately. A pinch seal unit 20 formed on one end of the bulb 2 contains an internal electrode 4 that is formed of a cold cathode. Yttrium oxide fluorescent material (Y203:Eu) is used as a fluorescent material, while xenon or mixed gas consisting of xenon and inert gas is used as noble gas. Thus, it is possible to reduce temperature dependency and improve luminous efficiency with less deterioration and a longer life of the fluorescent material achieved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a rare gas discharge lamp that emits orange light.

(Prior Art) Recently, attempts have been made to use low-pressure discharge lamps as display indicators on display panels of audio equipment, measuring instruments, and the like.

For example, a low-pressure discharge lamp such as a cold cathode fluorescent lamp is shaped into an extremely thin hollow needle with an inner diameter of 2 to 3 degrees or less.
A device has been developed in which one end of this discharge lamp is attached to the rotating pointer shaft of the meter, and the rotating pointer shaft rotates to rotate the discharge lamp as a unit. Moreover, when the discharge lamp is turned on, it emits light by itself and illuminates the display scale, so it has the advantage that no other special illumination is required.

It has traditionally been thought that discharge lamps used as pointers in such meters should preferably emit white or green light.

For this reason, in the conventional case, calcium halophosphate phosphor t3cai (PO
4) CaX2: (Sb, Mn) is used, and the bulb is configured to be filled with inert gas such as mercury (Hg) and argon (Ar). This product excites the calcium halophosphate phosphor with ultraviolet light around 254 nm emitted by mercury, causing it to emit white or green light.

However, if the color of the light emitted from the discharge lamp used as the above-mentioned guide is white light or green light, the color temperature may be high and the user may feel dazzling, which may cause eye fatigue. For this reason, there has recently been a trend to display meter needles and scales in orange, which gives a relatively soft feel.

In order to change the light emitted from the discharge lamp used for the pointer to an orange color, strontium phosphate phosphor ((S r, M) (
It is formed by using PO4)2:Sn) and filling the bulb with an inert gas such as mercury and argon. This also excites the strontium phosphate phosphor with ultraviolet light around 2 5 J ni emitted from mercury.
Emits an orange-red light color.

(Problems to be Solved by the Invention) However, the discharge lamp that emits orange light excites a phosphor with ultraviolet light emitted from mercury, and this mercury has strong temperature dependence. In other words, the mercury vapor pressure inside the bulb depends on the temperature of the bulb, and when the ambient temperature is low, the mercury vapor pressure is low, resulting in poor startability and low luminous efficiency even during stable lighting.

For this reason, when used in vehicle meters, etc., there will be differences in startability and brightness between cold and hot seasons, resulting in variations in characteristics.

For this reason, xenon (X,
e) Alternatively, it is conceivable to seal a mixed gas of xenon and other inert gas in the pallet to form a so-called xenon glow discharge lamp.

However, when the above-mentioned strontium phosphate phosphor is excited and emitted by ultraviolet light of around 1.47 nm emitted from xenon, the efficiency is extremely low, and moreover, the phosphor deteriorates prematurely.

The present invention was developed based on the above circumstances, and its purpose is to provide a material with low temperature dependence, high luminous efficiency, little deterioration of the phosphor, long life, and orange luminescence. The aim is to provide a rare gas discharge lamp.

[Structure of the Invention] (Means for Solving the Problems) The present invention uses a yttrium oxide phosphor (
Y203: Eu) is used, and xenon (Xe) or a mixed gas of xenon and an inert gas is used as the rare gas.

(Function) According to the present invention, since xenon (Xe) or a mixed gas of xenon and an inert gas is used as the rare gas that emits ultraviolet rays, it has less temperature dependence than mercury, and lamp characteristics are affected by temperature differences. Less variation. Yttrium oxide phosphor (Y203: E
u ), this phosphor effectively emits orange light when excited by the ultraviolet light around 147 nm emitted from the xenon.

(Example) The present invention will be described below based on an example shown in the drawings.

In the figure, ] indicates a cold cathode xenon glow discharge lamp used for an indicator needle of a meter, and this discharge lamp is equipped with a bulb 2 having an elongated discharge space 3 formed therein. The bulb 2 is made of a glass tube, and has, for example, an outer diameter of 2.5 mm, an inner diameter of 1.5 mm, and a total length of about 60 mm, and is shaped like a needle.

One end of the valve 2 has a pinch seal portion 20, and the other end has a tip-off structure.

An internal electrode 4 is sealed in a pinch seal portion 20 formed at one end of the bulb 2. The internal electrode 4 is formed of a cold cathode, and includes an electrode head 41, a lead wire 42 which also serves as an electrode axis, and an electron emitting material (emitter) (not shown) filled inside the electrode head 41. The Riet wire 42 passes through the crush sealing portion 20 in an airtight manner.

A phosphor coating 6 is formed on the inner surface of the bulb 2 facing the discharge space 3. The phosphor coating 6 uses a yttrium oxide phosphor (Y203 diEu).

In addition, xenon (Xe) is contained in the valve 2 at 5 to 40 T.
orr, the preferred range is about 20 to 40 Torr.

An external electrode 7 is provided on the outer surface of the bulb 2 in the form of a band along the axial direction. This external electrode 7 is constructed by coating a paste such as carbon phenol or silver epoxy in a band shape along the axial direction of the bulb 2, and then firing this.

One end of the external electrode 7 is located at a portion facing the internal electrode 4, and the other end extends to the tip-off portion of the bulb 2.

A first power receiving terminal 10 is formed on the outer surface of the end of the bulb 2 that seals the cold cathode 4 inside. This first
The power receiving terminal 10 is formed in the form of a film formed by applying and baking a conductive paste such as silver epoxy, and is connected to the lead wire 42 .

Further, on the outer surface of the bulb 2, the first power receiving terminal 10 is provided.
A second power receiving terminal 11 is formed at a position spaced apart from each other in the axial direction. The second power receiving terminal 11 is also made by applying and firing a conductive paste such as silver epoxy, and extends in the circumferential direction with a predetermined width. This second power receiving terminal 11 is connected to the external electrode 7.

Note that the second power receiving terminal 11 is formed so as to avoid a slit portion 9 of the light shielding film 8, which will be described later.

Furthermore, a light-shielding coating 8 is formed on the outer surface of the bulb 2.

The light-shielding film 8 has components of carbon, epoxy resin, and adhesive, and is applied to the surface of the bulb 2 on which the external electrode 7 is provided, covering the external electrode 7, and is formed by firing this coating film. ing.

The light-shielding film 8 has a light-transmitting slit portion 9 located on a surface opposite to the surface on which the external electrode 7 is provided and extending in the axial direction. In other words, the light-transmitting slit portion 9 is formed by the light-shielding coating 8
It is formed of a transparent part that does not form a

To explain further, as shown in cross section in FIG. 2, an external electrode 7 is provided on one side of the outer surface of the bulb 2, and this external electrode 7 is covered with a light shielding film 8. A light-transmitting slit portion 9 on which no light-shielding film 8 is formed is formed on the other surface 180 degrees opposite to the light-shielding film 7 .

The light within the bulb 2 is emitted to the outside only through the light transmitting slit portion 9, so that the discharge lamp 1 has an aperture shape.

In the xenon discharge lamp 1 configured in this manner, the first power receiving terminal 10 and the second power receiving terminal 11 are connected to a high frequency power source, and high frequency power is supplied to the internal electrode 4 and the external electrode 7.

Therefore, glow discharge occurs between the internal cold cathode 4 and the external electrode 7 within the discharge space 3.

This glow discharge excites the xenon gas filled in the discharge space 3, and xenon has a unique spectrum, for example 147
Emit ultraviolet light around nm. This short wavelength light is covered by a phosphor W! 6 is excited, and this phosphor coating 6 generates visible light. Since the phosphor of the present invention uses a yttrium oxide phosphor (Y2O,: Eu), it is excited by the ultraviolet rays and emits orange light.

Such orange light is emitted to the outside through the slit portion 9.

For this reason, in addition to the fact that the bulb 2 is originally thin, the narrow slit portion 9 further restricts the band of light, so that the discharge lamp 1 emits orange light in the form of a thin needle-like band.

For this reason, this discharge lamp 1 shows a display scale and emits light by itself, so that no other special light source is required.

Since such cold cathode xenon glow discharge lamps do not contain mercury, they are less affected by temperature, and are superior to conventional lamps containing mercury in terms of lamp characteristics such as startability and luminous efficiency. ing.

As the rare gas, we used xenon (Xe), which emits ultraviolet light around 1.47nllll, and as the phosphor, we used a yttrium oxide phosphor (Y203: Eu), so this phosphor can be made from the above xenon. It is efficiently excited by the emitted ultraviolet light around 147 nm and emits orange light.

Therefore, when applied to a meter, it can be displayed in orange, which is easy to identify and is soft on the eyes.

A combination of these xenon and yttrium oxide phosphors results in less deterioration of the phosphors and a long life.

FIG. 3 shows the emission spectrum characteristics, and the solid line shows the emission spectrum characteristics due to the combination of the xenon and yttrium oxide phosphors.

The characteristics shown by the broken line are the emission spectrum characteristics due to the combination of mercury and yttrium oxide phosphor, and in this case, pink light is emitted and the desired orange color cannot be obtained.

Note that the present invention is not limited to the above embodiments.

In other words, the discharge lamp of the present invention is not limited to the case where it is used as an indicator needle of a meter; in short, it may be any rare gas discharge lamp that has the configuration specified in the claims and emits orange light, and can be used as a color lamp. It may be. therefore,
It may also be a hot cathode discharge lamp.

Further, the rare gas sealed in the bulb is not limited to xenon alone, and a mixed gas containing at least one of neon, argon, and krypton in addition to xenon may also be sealed.

Further, the valve is not limited to a straight shape, but may be a bent shape.

[Effects of the Invention] As explained above, according to the present invention, xenon (Xe) or a mixed gas of xenon and an inert gas is used as the rare gas that emits ultraviolet rays, so it has less temperature dependence than mercury. This reduces variations in lamp characteristics due to temperature differences.

Yttrium oxide phosphor (Y20) is also used as a phosphor.
3: Eu), this phosphor effectively emits orange light when excited by ultraviolet light around 147 nm emitted from the xenon. and,
In this case, there is an advantage that the phosphor deteriorates less and has a longer life.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, in which Fig. 1 is a perspective view of a xenon glow discharge lamp used as a meter pointer, Fig. 2 is a cross-sectional view taken along line U-n in Fig. 1, and Fig. 3 shows an emission spectrum. FIG. 1... Discharge lamp, 2... Bulb, 4... Internal electrode,
6. Phosphor coating, 7. External electrode, 8. Light-shielding coating, 9. Translucent slit portion. Applicant's agent Patent attorney Takehiko Suzue 9th, Figure 2

Claims (1)

[Claims] A rare gas discharge lamp in which a rare gas that emits ultraviolet rays is sealed inside a bulb with a phosphor film formed on the inner surface, wherein a yttrium oxide phosphor (Y_2) is used as the phosphor.
A rare gas discharge lamp characterized in that it uses xenon (Xe) or a mixed gas of xenon and other inert gas as the rare gas.