JPS5935351A - Discharge lamp - Google Patents

Abstract

PURPOSE:To obtain the captioned discharge lamp having uniform brightness on the luminous surface, a low operating voltage and thin construction, by disposing comb-like facing electrodes on the surface of a back substrate, covering the electrodes with dielectric, and hermetically sealing the captioned lamp with a light-transmitting front substrate in order to enclose rare gas thereinto. CONSTITUTION:On the surface of a slender back substrate 2 made of electric insulator, a comb-like electrode 3 and a comb-like electrode 3' are disposed to face each other spaced at a distance on the identical flat plane; said comb-like electrode 3 has an external leading-out electrode part 3a and a ribbon-like discharge electrode part 3b which projects from said electrode 3a like the teeth of a comb, and said comb-like electrode 3' has an external leading-out electrode and a discharge electrode part 3'b. Said electrodes 3, 3' are covered with dielectric 4 and further the surface of the dielectric 4 is covered with a protecting layer 8. In addition, a light-transmitting front substrate 6 made of the electric insulator is disposed through a discharging space 5 formed by inserting a spacer 9; the peripheral parts of substrates 2, 6 being hermetically sealed in order to form a gas-tight container 7. A discharging medium mainly composed of rare gas is enclosed in the container 7. Thus, a thin discharge lamp having uniform brightness on the luminous surface and a low operating voltage can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a discharge lamp in which comb-shaped electrodes are disposed on an electrically insulating substrate so as to face each other with a gap in between.
The present invention relates to a discharge lamp that is effective when applied to various light sources, such as a light source for film display, a light source for static elimination of photoreceptors in electronic copying machines and facsimile machines, and a back light source for liquid crystal displays.

Generally, in a panel-shaped discharge lamp in which two electrically insulating substrates are arranged facing each other with a discharge space in between, electrodes are arranged facing only on one substrate (7). Placing electrodes on opposite sides of each panel provides greater freedom in design in terms of electric field distribution, operating voltage, panel thickness, etc. However, on the other hand, there are also requirements for workability in substrate processing, and When attaching a phosphor to a substrate, it is necessary to arrange electrodes facing each other on only one substrate, and in this case, as mentioned above, the degree of freedom in design is reduced. This makes it difficult to select optimal conditions.

Therefore, in the conventional type discharge lamp in which electrodes are disposed only on one substrate, as shown in FIG. They are arranged facing each other with a discharge space 5 in between, and the peripheral part is covered with a sealing material 1o.
The discharge lamp 1 is constructed by sealing the envelope to form an airtight envelope 7 and filling it with discharge gas. Further, a pair of ribbon-shaped electrodes 6°3' are disposed on the surface of the rear substrate 20 so as to face each other in the same plane, and the electrodes 6°3' are covered with a dielectric material 4, and the top thereof is covered as necessary. With a structure covered with a protective layer 8, it can be operated in an indirect discharge mode, and the light emitted by the discharge can be directly emitted, or by coating a phosphor (not shown) on the inner surface of the front substrate 6, the phosphor can be excited and emitted light. are used as various light sources.

However, in the electrode structure of the conventional discharge lamp 1, the gap between the electrodes 3, 3' is smaller than the gap between the opposing electrodes 3, 3'.
Since the width of ' is very large, there will be a difference in the electric field strength between the parts near and far from the gap between the electrodes 6 and 3', and the amount of radiation 12 generated by the discharge will be as shown in Figure 1 @. As shown (
, it is more abundant in the electrode portions where the electric field strength is strong, that is, the portions close to the electrode gap, and is less in the electrode portions where the electric field strength is weak, that is, the portions far from the electrode gap. Therefore, when this is visually observed from the front substrate 6 side of the discharge lamp 1, the central part of the light emitting surface 1B of the discharge lamp 1 is bright, and the side edges are dark, making the brightness unevenness of the light emitting surface 13 extremely noticeable. becomes. On the other hand, K, which eliminates the above-mentioned brightness unevenness, is the electric current 1 (
71) Increase the electric field strength of 5.3' or electrode 3.
5' and the inner surface of the front substrate 6 to facilitate the diffusion of the discharge and increase the uniformity of the electric field strength in each part of the electrode, but there is no way to increase the electric field strength. This method increases the operating voltage of the discharge lamp, and increasing the distance between the electrode and the front substrate increases the thickness of the discharge lamp and increases the absorption of radiation by the discharge gas. There is a problem that brightness decreases.

The present invention was devised to solve the above-mentioned problems, and by increasing the uniformity of the electric field strength on the electrode, uniform brightness can be obtained over the entire light emitting surface, and the thickness can be reduced. The object is to provide a discharge lamp that is thin and has a low operating voltage.

In order to achieve the above object, the discharge lamp of the present invention has comb-shaped electrodes disposed on the surface of a back substrate made of an electrical insulator so as to face each other with a gap in the same plane. as well as covering the electrode and dielectric,
A translucent front substrate made of an electrical insulator is arranged to separate the back substrate from the discharge space, and the periphery of both substrates is sealed to form an airtight container. It has a configuration in which a discharge medium mainly consisting of gas is sealed, and an alternating electric field is applied between both electrodes to operate in an indirect discharge mode.An embodiment of the present invention will be described below based on the drawings. do. Second
Figures 1 and 2 are an exploded perspective view of a main part and a sectional view showing a light emitting state of a discharge lamp according to an embodiment of the present invention, respectively. In the figure, 1 is the entire discharge lamp, 2 is a rear substrate, 5
．． 3' is an electrode, 4 is a dielectric, 5 is a discharge space, 6 is a front substrate, and 7 is an airtight container. Thus, the discharge lamp 1 of the present invention has an external lead-out electrode part 6a and a plurality of comb-teeth shaped electrodes formed from the external lead-out electrode part 6a on the surface of the elongated back substrate 2 made of an electrical insulator such as glass or ceramic. One comb-shaped electrode 6 has a ribbon-shaped discharge electrode part 6b protruding from the outside, and also has an external lead-out electrode part (not shown) and a plurality of ribbon-shaped ribbon-like discharge electrode parts 6b protruding from the external lead-out electrode part (not shown). The other comb-shaped electrode 3' having a discharge electrode part 3'b7
One of the external lead-out electrode parts 3a and the other external lead-out electrode part are formed on one end and the other end of the back substrate 2, and one discharge electrode part 6b and the other discharge electrode part are formed. 3'b are disposed so as to extend in the longitudinal direction of the rear substrate 2 and are alternately arranged facing each other with small gaps in between. In this case, the electrodes 3 and 5' are applied to the surface of the rear substrate 2 by thick film printing technology;
Using other vapor deposition techniques or plasma spraying techniques using reducing gases mainly composed of rare gases, conductive materials such as iron, Ni-Sokel, and chromium-kowara alloys are applied in a predetermined number of turns. It can be easily formed by adhering it. 1, the above comb-shaped electrode 6.3' is g
The surface of the dielectric 4 is further coated with a material having a small work function and strong against ion bombardment, depending on the needs of the electric body 4. The dielectric material 4 and the protective layer 8 can be easily deposited and formed by thick film printing technology, vapor deposition technology, plasma spraying technology, or the like. Furthermore, a comb-shaped electrode 3 is provided on the front surface of the rear substrate 2.
, 3', thin plate glass covering the dielectric 4 and the storage layer 8;
A long and narrow front substrate 6 made of a translucent electrical insulator such as glass is inserted through a discharge space 5 formed by inserting a spacer 9 made of a glass rod or a glass piece.
The peripheries of the rear substrate 2 and front substrate 6 are sealed with a vacuum adhesive 10 such as frit glass to form an airtight container 7.In addition, an exhaust pipe is attached to the outside of the rear substrate 2. 11, a discharge gas consisting mainly of rare gases such as Ne, A, and R alone or in a mixture is sealed inside the airtight container 7, and an alternating electric field is applied to both electrodes 6 and 6'. ] In addition, the second
As shown in FIG. a3), discharge light emission 12 corresponding to a plurality of discharge electrode parts is generated and the light is emitted from the discharge surface 13.

FIG. 6 is an exploded perspective view and a sectional view of a main part of a discharge lamp according to another embodiment of the present invention, respectively. That is, a fluorescent material 14 is coated on the surface facing the rear substrate 2, and an ultraviolet emitting gas mainly consisting of a single or mixed rare gas such as E (e, Xe, etc.) is placed inside the airtight container 7. is inserted into the other comb-shaped electrode 31 on the back surface, and an alternating electric field is applied to the other comb-shaped electrode 31 to operate in an indirect discharge mode, and the ultraviolet rays generated by the discharge excite the fluorescent substance 14.
It provides uniform light emission in the form of light. Similarly, in this embodiment, configurations other than those described above, such as the shape, arrangement, and texture of the electrodes 3 and 5', the dielectric material 4 covering the electrodes 6 and 51, the protective layer 8, or the rear substrate 2 and front substrate 6 shape, material,
The arrangement etc. are essentially the same as the embodiment shown in FIG.

A discharge lamp 1 according to another embodiment of the present invention shown in FIG.
Lead portions 6C are formed on one end and the other end, respectively, and extend to one side edge of the rear substrate 2 in the longitudinal direction and the reinforcing side edge of the external lead-out electrodes 3a and 3/a, respectively. and 31c, and further connect the lead parts 3C and 3
Comb-shaped electrodes 3 and 3' in which a plurality of discharge electrode parts 3b and 3'b extending in the width direction of the rear substrate 2 and protruding from /c in a comb-like shape are alternately arranged with a minute gap in between. is disposed on the surface of the rear substrate 2 facing the front substrate 6, and an ultraviolet emitting gas is sealed in an airtight container 7 and operated in an indirect discharge mode to generate ultraviolet rays to emit light on the front substrate 6. The fluorescent substance 14 deposited on the inner surface is excited (to obtain uniform light emission in the form of transmitted light). In this embodiment, structures p'Q other than those described above, that is, the material of the electrodes 3 and 3',
The shape, material, arrangement, etc. of the dielectric 4, the retentive layer 8, the back substrate 2, and the front substrate 6, which cover the electrode openings 3', are essentially the same as those in the embodiment shown in FIG.

The embodiment shown in FIG. 5 has an electrode configuration in which the other discharge electrode part 5'b is a set of two, and one discharge electrode part 3'b
b is arranged between two discharge electrode portions 3'b with a minute interval therebetween. Note that the other discharge electrode section 3'b2
The area of one discharge electrode 3b is selected so that the total area of the two discharge electrodes 3b is the same. This embodiment is essentially the same as the embodiment shown in FIG. 4 in terms of configuration, discharge mode, light emission format, etc. other than those described above.

In the configuration of the discharge lamp 1 described above, the discharge electrode portion 5b of the electrodes 3, 3' is as shown in FIG.

If the width of 3'b is t1, the size of the gap between the discharge electrode parts 3b and 3'b is 81, and the height of the discharge space is d, then 1/4<
d/(t+S)<t, 8X to satisfy the condition of 2
By appropriately selecting the value of d, it is possible to obtain a discharge lamp with particularly low operating voltage required for discharge over the entire area of the electrodes and with high luminous efficiency.

That is, when set to d/(t+8))1/4,
It is easy to diffuse the discharge, and a discharge over the entire area of the electrode can be obtained at a very low operating voltage.In addition, when d/(t+s) is set to 2, the radiation generated by the discharge is absorbed by the filled gas. Since the light reaches the front substrate with almost no radiation, high brightness can be obtained. This effect is particularly significant in the case of ultraviolet radiation, which is easily absorbed by the gas enclosed.

As explained above, the discharge lamp of the present invention has an electrode structure in which comb-shaped electrodes coated with a galvanic material are disposed on the surface of the rear substrate so as to face each other with a gap in between. This eliminates the non-uniformity of the electric field strength, which reduces the operating voltage required to discharge the entire area of the electrode, and even if the distance between the electrode and the front substrate is reduced, the dispersion of the discharge is not prevented. , uniform brightness can be obtained over the entire emitting surface, and the structure is thin with low operating voltage.
It can be used suitably for various optical images, including a light source for film display, a light source for static elimination of photoreceptors in electronic copying machines and facsimile machines, and a back light source for liquid crystal displays.

[Brief explanation of the drawing]

1(A) and 0 are an exploded perspective view of a main part of a conventional example and a cross-sectional view showing a state of light emission, respectively, and FIGS. 2(G) and 0 are an exploded perspective view of a main part of an embodiment of the present invention. Fig. 3 and @ are a perspective view and a sectional view of a main part of another embodiment of the present invention, Fig. 4 is an exploded perspective view of a main part of another embodiment of the invention, FIG. 5 is an exploded perspective view of a main part of another embodiment of the present invention, and FIG. 6 is a sectional view showing the height of the discharge space, electrode width, and distance between electrodes of the embodiment of the present invention. 1...Discharge lamp 2...Back force plate 3, 3'
...Electrodeposition 4...Visiting object 5...Discharge space
6...Front board 7...Airtight container 14...
・Fluorescent substance (A) Figure 41 (B) (B)

Claims (2)

[Claims] (1) Comb-shaped electrodes are disposed on the surface of a back substrate made of an electrical insulator, facing each other with a gap in between, and the electrodes are covered with a dielectric material. A translucent front substrate made of an electrical insulator is placed so as to cover the back substrate and the discharge space, and the peripheries of both substrates are sealed to form an airtight container. A discharge lamp 0 characterized in that it is filled with a discharge medium mainly composed of a rare gas. (2) A fluorescent substance is coated on the inner surface of the front substrate [7] The discharge according to claim 1, wherein an ultraviolet emitting gas is filled as a discharge medium to excite the fluorescent substance to emit light by discharge. lamp.