JP2003036815A - Fluorescent lamp and lighting system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluorescent lamp and its lighting system, which allows electrons to transfer more easily and improves a darkness starting characteristic without complicating and enlarging the end part structure of the fluorescent lamp, and also without need for an additional power source. SOLUTION: The fluorescent lamp is characterized in that in the tubular bulb (2) which rare gas, or rare gas and mercury is sealed in with both ends blocked and a phosphor film (3) formed on the inner surface thereof, a pair of the external electrodes (4), (5) are disposed on the external surfaces of both ends in the tube axis direction of the tubular bulb (2), and the end surfaces in the tube axis direction of the respective external electrodes (4), (5) are formed in toothing (4a).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention comprises a fluorescent lamp used as a light source for liquid crystal backlights, a scanner light source for facsimiles, an eraser light source for copying machines, and other light sources for displays, decorations, displays, and the like. Lighting device.

[0002]

2. Description of the Related Art Conventionally, a fluorescent lamp of this type has a phosphor film formed on the inner surface of a tubular bulb whose both ends are sealed, and a rare gas containing xenon gas as a main component and mercury are enclosed therein. A structure in which an electrode that connects to an introduction line that is hermetically sealed inside both ends of a tubular bulb is sealed, and an aperture portion (opening for light transmission) is formed along the axial direction of the tubular bulb by removing the phosphor layer. There are many.

In recent years, as shown in FIG. 8, a phosphor coating is provided on the inner surface of the tubular bulb (52) and an aperture portion (56) is formed along the bulb axis of the bulb (52). By providing a pair of strip-shaped external electrodes (9) on the outer surface of the tubular valve (52) in the longitudinal direction along the tube axis of the valve (52) with a predetermined spacing therebetween, and vertically spaced from each other, A configuration has been proposed in which the electrode (9) is not provided inside the tubular valve (52). By attaching a terminal (10) made of a metal member having excellent conductivity to the end portion of the strip-shaped external electrode (9) and connecting the terminal (10) to a lighting circuit device by a lead wire (not shown), the lighting device is completed. It is configured.

In the fluorescent lamp having the aperture portion, high-frequency electric power is supplied between the strip-shaped external electrodes to generate high-frequency discharge in the tubular bulb, so that rare gas such as xenon gas sealed in the tubular bulb is generated. Ionizing gas,
The phosphor is excited to emit light, and the emitted visible light of the phosphor coating and the light reflected by the strip-shaped external electrode are emitted to the outside from the aperture portion which is the light projection opening of the tubular bulb. .

Since the apertures of these tubular bulbs have a brightness several times higher than that of the phosphor layer and are formed along the tube axis direction of the bulbs, the illuminance distribution reaches the ends of the tubular bulbs. It is uniform.

[0006]

A fluorescent lamp having an external electrode can obtain a high light projection output and is not particularly inconvenient in a relatively bright place during the day.
In a completely dark state such as at night, that is, in a dark state, the discharge is delayed and it takes a long time to start the start, and there is a problem that it does not light for a predetermined time even if a voltage is applied.

In order to solve this problem, a conductive material is provided in the discharge space of the tubular valve, and when electric power is externally supplied to the external electrode, the discharge space is short-circuited and a high electric field is partially generated between the external electrodes. However, there has been proposed a device in which a discharge is generated to generate ultraviolet rays.

According to the above method, there is an advantage that the starting characteristic in the dark state is improved, but since the conductive material is provided on the inner surface of the end portion inside the glass bulb, the power consumption increases, There was the problem of being uneconomical.

Further, a small heat-generating light bulb or an auxiliary light source for LED is installed near the high-voltage side electrode to utilize the photoelectric effect of the light emitted by them, or α-alumina is formed on the glass inner surface of the tubular valve near the electrode. , CsSO4 (cesium sulfate) is applied, and the free electrons emitted from these oxides are used to cope with the dark starting characteristic. However, if a small light bulb or an auxiliary light source such as an LED is installed near the electrodes, the rubber holder that holds the fluorescent lamp will become larger and the shape will become complicated, and metal oxides will fluoresce near the electrodes. When applied to the body surface, the amount of light at the phosphor coating portion is reduced, so the dark starting characteristics have not been completely improved.

The present invention has been made in view of the above problems, and an object thereof is to transfer electrons without complicating or enlarging the end structure of a fluorescent lamp and without requiring a separate power source. It is an object of the present invention to provide a fluorescent lamp and a lighting device for the fluorescent lamp, in which a dark state is created and which has improved dark starting characteristics.

[0011]

In order to solve the above-mentioned problems, the invention according to claim 1 encloses a rare gas or a rare gas and mercury to close both ends and form a phosphor coating on the inner surface. In this tubular bulb, external electrodes are arranged on the outer surfaces of both ends of the tubular bulb in the tube axial direction, and the tube axial ends of the respective external electrodes are formed in a concavo-convex shape. Depending on the configuration, an environment is created in which electrons easily move, and the electric field is concentrated to facilitate the discharge, so that the discharge is started without delay and the dark starting characteristic can be improved.

According to a second aspect of the present invention, a rare gas, or a rare gas and mercury are enclosed to close both ends, and an outer surface of both ends in the tube axis direction of a tubular valve having a phosphor coating on the inner surface is external. It features a fluorescent lamp in which electrodes are arranged and a coiled conductive metal is arranged on the end surface of this external electrode.Since the end structure of the fluorescent lamp can be simplified and miniaturized, the inside of the glass tube can be reduced. Since the photoelectric effect is used as compared with the case where the metal oxide is applied to the substrate, the effect of improving the dark starting characteristic is also increased.

The invention according to claim 3 is characterized in that the coil-shaped conductive metal is used as a closed loop high frequency induction power source, and a separate power source can be eliminated.

According to a fourth aspect of the present invention, a rare gas, or a rare gas and mercury are enclosed to close both ends, and an outer surface is provided on the outer surface of both ends in the tube axis direction of a tubular valve having a phosphor layer formed on the inner surface. Characterized by a fluorescent lamp in which electrodes are arranged and the outer diameter of the glass tube at both ends of the tubular bulb is reduced so that the outer diameter of the state where the outer electrodes are adhered and the outer diameter of the central portion of the glass tube are almost equal. The invention according to claim 5, wherein the fluorescent lamp holding portion as the illuminating device is not larger than other portions and the degree of freedom of installation can be increased. 4. The fluorescent lamp according to any one of 4 above,
The lighting device is provided with a lighting circuit device connected to the fluorescent lamp, and the dark starting characteristic can be improved.

[0015]

DETAILED DESCRIPTION OF THE INVENTION An embodiment of the present invention will be described below with reference to the drawings. In the fluorescent lamp (1) shown in FIGS. 1 and 2, both ends of a tubular bulb (2) are sealed, and a phosphor coating (3) is formed on the inner surface of the both ends except for a small length dimension. At the same time, as a discharge medium that emits ultraviolet rays by receiving a discharge inside, one of rare gases such as xenon (Xe), argon (Ar), krypton (Kr), neon (Ne), or a mixed gas thereof. And mercury (Hg) is enclosed, and external electrodes (4) and (5) are provided on the outer surfaces of both ends of the tubular valve.

The phosphor coating (3) is formed with a thickness of 15 to 25 μm along the bulb axis of the tubular bulb (2), and the phosphor is provided in a portion facing the light guide plate of the lighting device (not shown). An aperture portion (6), which is an opening for light transmission, in which the coating film (3) is removed is provided.

The external electrodes (4) and (5) provided on the outer surfaces of both ends of the tubular valve (2) are made of conductive paint such as conductive copper foil, aluminum tape or silver paste. The tubular bulb (2) is wound or coated in an annular shape on each end, and is connected to the lighting device (8) by a lead wire (7).

High-pressure side electrode (4) of the tubular valve (2)
Is formed on the end face so as to have a concavo-convex shape directed toward the electrode part (5) at the other end and having a protruding part (4a) at the tip. Then, by applying a high voltage, an electric field is concentrated on the tip end protruding portion (4a) of the electrode end surface to form a high electric field, and a situation in which discharge is likely to occur is positively created to improve the starting characteristics in the dark due to discharge. It is a thing.

The shape of the end face of the electrode is not limited to the above-mentioned concavo-convex shape, but the projection (4) having a zigzag shape shown in FIG.
b) or the protrusion (4c) having the corrugated shape shown in FIG. Further, as shown in FIG. 5, the electrode (4) may be formed in a narrow band shape and meandered and attached to form the protruding portion (4d).

As another embodiment of the present invention, as shown in FIG. 6, tungsten (W) is formed inside the glass tube near the external electrode (14) at the high pressure side end of the tubular valve (12). A coil-shaped light emitting member (9) made of a metal such as nickel (Ni), iron, copper, molybdenum (Mo), tantalum (Ta), cobalt (Co), or aluminum may be housed and arranged. This light emitting member (9)
Is energized by an external power source other than the high-voltage power source for discharge, or the coil (9) is closed loop as shown in the figure, and the coil (9) is driven by high-frequency induction of high voltage for discharge. By making light emit, a situation in which thermoelectrons are easily activated by its photoelectric effect is promoted and discharge is promoted, so that even in a dark state, there is no delay in discharge and it is started.

In each of the above-mentioned embodiments, the end shape of the tubular valve (2) has substantially the same diameter as that of the central part, but in the present invention, as shown in FIG. The outer diameter of the portion of the glass tube (22a) in which the external electrode (24) is arranged is formed to be slightly smaller than the light emitting portion in the central portion of the tubular bulb (22). Then, the external electrode (24) in a state of being adhered from the outer surface of the tubular valve (22).
The outer diameter of the portion is made equal to the outer diameter of the central light emitting portion of the bulb (22). With this configuration, the holding portion at the end of the fluorescent lamp (21) in the lighting device does not have a large diameter,
Even when a large number of fluorescent lamps used for a liquid crystal backlight or the like are arranged in a row, a degree of freedom in installation dimensions can be obtained, and the lamps can be easily arranged.

According to the cold cathode fluorescent lamp having such a structure, as shown in FIG. 1, when a high frequency power source is applied from the lighting circuit device (8) to the external electrode (4), the tubular bulb (2). A discharge occurs in the mercury, which is excited by the discharge.
The inclusions such as rare gas generate ultraviolet rays, and the ultraviolet rays excite the phosphors on the inner surface of the tubular bulb (2), so that the phosphor coating (3) is irradiated over the entire area to obtain visible light. The visible light is directly emitted to the outside through the phosphor coating (3) together with the aperture portion (6) of the tubular bulb (2) which is an opening for light projection. Used as a light source for facsimiles, etc.

Since the electrodes (4) and (5) are provided as external electrodes on the outer surfaces of both ends of the tubular bulb (2), they are conventional fluorescent lamps containing mercury and a rare gas as inclusions. Like the electrode system enclosed in a tubular bulb, the surface of the phosphor coating in the vicinity of the electrode becomes black due to the reaction of the enclosed mercury with the electrode, so-called sputtering causes the brightness of the lamp to decline. It is possible to prevent the life of the electrode from being shortened due to the reduction of the enclosed mercury.

Further, according to the above-described embodiment of the present invention, even if the external electrode method is used, it is described as the prior art.
The aperture part is formed along the valve axis, and a pair of strip-shaped external electrodes are provided on the outer surface of the tubular valve along the valve axis with a predetermined interval. There is an advantage that there is no problem of area reduction and there is no restriction on the light projection direction due to the positional relationship between the strip electrode and the aperture portion.

[0025]

As described above, according to the present invention,
Compared with the conventional internal electrode method, mercury is not consumed by sputtering, so the electrode life is not reduced, and it is possible to form a fluorescent lamp with a minimum amount of mercury used, which is environmentally friendly. In addition to contributing to the above, the brightness of the plate surface of the light guide plate is improved when incorporated in the lighting device unit.

Further, the uneven shape of the end face of the external electrode makes it easy for electrons to move and positively creates a state for concentrating the electric field, which facilitates the discharge, so that the discharge is started without delay. The dark starting characteristics can be improved.

According to the second aspect of the invention, the structure of the end portion of the fluorescent lamp can be simplified and downsized, and if a coil or the like is connected in a closed loop, a separate power source can be eliminated. Further, as compared with the conventional case where the metal oxide is applied to the inside of the glass tube, the photoelectric effect is utilized, so that the effect of improving the dark starting characteristic is increased.

According to the invention of claim 4, the fluorescent lamp holding portion as the illuminating device is not larger than the other portions, and the degree of freedom of installation can be increased.

[Brief description of drawings]

FIG. 1 is a partially cutaway front view of a fluorescent lamp showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a front view of a main part of a fluorescent lamp showing another embodiment of the present invention.

FIG. 4 is a front view of a main part of a fluorescent lamp showing another embodiment of FIG.

5 is a partially cutaway front view showing still another embodiment of FIG. 3. FIG.

FIG. 6 is a cross-sectional view of main parts of a fluorescent lamp showing still another embodiment of the present invention.

FIG. 7 is a cross-sectional view of main parts of a fluorescent lamp showing still another embodiment of the present invention.

FIG. 8 is a perspective view of a conventional fluorescent lamp.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Fluorescent lamp 2 ... Tubular bulb 3 ... Phosphor coating 4, 5 ... External electrodes 4a, 4b, 4c, 4d ... Electron end surface uneven projection tip 6 ... Light projection opening (aperture) 9 ... Coil shape Light-emitting member 22a ... Small-diameter portion at end of tubular bulb

Claims (5)

[Claims] 1. A rare gas, or a rare gas and mercury are sealed to close both ends, and external electrodes are arranged on the outer surfaces of both ends in the tube axis direction of a tubular bulb having a phosphor coating formed on the inner surface, respectively. A fluorescent lamp in which the ends of the external electrodes in the tube axis direction are formed in a concavo-convex shape. 2. A rare gas, or a rare gas and mercury are sealed to close both ends, and external electrodes are arranged on the outer surfaces of both ends in the tube axis direction of a tubular bulb having a phosphor coating formed on the inner surface. A fluorescent lamp in which a coil-shaped conductive metal is arranged on an end surface of an external electrode. 3. The fluorescent lamp according to claim 2, wherein the coiled conductive metal is used as a closed loop high frequency induction power source. 4. A tubular gas in which a rare gas or a rare gas and mercury are enclosed to close both ends, and external electrodes are arranged on the outer surfaces of both ends in the tube axis direction of a tubular valve having a phosphor coating formed on the inner surface thereof. A fluorescent lamp characterized in that the outer diameter of the glass tube at both ends of the bulb is reduced so that the outer diameter in a state where the outer electrodes are adhered is substantially equal to the outer diameter of the central portion of the tubular bulb. 5. A lighting device comprising a fixture main body, the fluorescent lamp according to claim 1 provided in the fixture main body, and a lighting circuit device connected to the fluorescent lamp. .