JPH0378904A - Luminaire - Google Patents

Abstract

PURPOSE:To prevent the generation of leakage of the current between a lamp and a heating means and improve the flux distribution characteristic of the generated light by interposing an insulating member for reflecting the visible radiation between a base member and the lamp. CONSTITUTION:A heater 15 as a heating member is fixed on the bottom surface of a casing 1 with the adhesive 4. An insulating film 2 of which largeness is as same as the heater 15 in outline and keeping insulation from the heater 15 and reflecting the visible radiation is fixed on the heater 15 with the adhesive 4. In this case, the insulating member 2 having the high visible radiation reflectance is located between a fluorescent lamp 6 and a heater main frame 16 located in the casing 1, and the leakage of the current to be generated during the lighting of the fluorescent lamp 6 is prevented by the insulating member 2. Since the material having the high visible radiation reflectance is used, the flux distribution characteristic is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a lighting device that uses a discharge lamp such as a fluorescent lamp as a light source and is suitable for use as a backlight for a liquid crystal television or a liquid crystal meter.

(Conventional technology) LCD televisions, LCD meters, etc. are designed to illuminate the liquid crystal surface by shining light from the back of the liquid crystal panel. Therefore, a lighting device that can emit light with even brightness is required.

This type of backlight has conventionally housed a hot cathode or cold cathode fluorescent lamp as a light source in a gauge having a semi-slanted inner surface, and the light emitted from the lamp is reflected by the reflective surface to open the casing. A lighting device is used in which light is emitted to the outside through a light diffusing and transmitting plate installed in the irradiation part.

When a hot cathode or cold cathode fluorescent lamp is used as a light source, these fluorescent lamps have superior luminous efficiency, generate less heat, and have a longer lifespan than incandescent bulbs.
Since it has a narrow discharge path, it has advantages such as a large light emitting area and a uniform light emission distribution.

In the case of fluorescent lamps, it is easy to configure the discharge path into a bent shape, such as a U-shape or a W-shape. Fluorescent lamps with such a bent shape have a wider light-emitting surface in plan, so it is easier to configure the discharge path in a bent shape, such as a U-shape or a W-shape. This is advantageous for illuminating a wide display surface with uniform brightness.

If you try to start a low-pressure mercury vapor discharge lamp, such as the fluorescent lamp mentioned above, in a low-temperature atmosphere, the emission of electrons will not be smooth, so the starting voltage will be high and the rise time will be long. In addition, if the ambient temperature is low during lighting, the vapor pressure of the luminescent metal or luminescent gas that is enclosed will be low, resulting in a decrease in luminous efficiency.

For this purpose, means is provided for heating the discharge lamp with a heater.

(Problem to be Solved by the Invention) However, when the heating means described above is used, current leakage may occur between the lamp and the heating means when the lamp is operated by means such as a high-frequency lighting circuit. .

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a lighting device that prevents current leakage between a lamp and a heating means and that has good light distribution of the generated light. .

[Structure of the Invention] (Means for Solving the Problems) The present invention provides a lighting device comprising a lamp and a heating element for heating the lamp disposed in a main body having a translucent substrate on one side, wherein the substrate is The lamp is characterized in that an insulating member that reflects visible light is interposed between the lamp and the lamp.

(Function) According to the present invention, an insulating member with a high visible light reflectance is arranged between the fluorescent lamp placed in the gauging and the heater body, and the insulating member prevents current leakage that occurs during lighting of the fluorescent lamp. [This can be prevented.]

Furthermore, since a material with a high visible light reflectance is used, the light distribution characteristics are good, and when used as a backlight of a liquid crystal display device, the liquid crystal display can be performed without uneven brightness.

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

In the figure, ■ is a main body that has a translucent base on one side, and is a tray-shaped casing with an open top surface.For example,
It is made of synthetic resin such as polycarbonate, and the upper opening is used as the irradiation part.

On the bottom of this gauging 1 is a heater 15 which is a heating element.
is fixed via adhesive 4.

Further, on this heater 15, there is a space between this heater 15 and the road.
The insulating film 2, which is an insulating member for maintaining insulation with the heater 15 and reflecting visible light, is attached to the adhesive 4.
It is fixed to the above-mentioned holder 15 via.

Furthermore, on this insulating film 2, a bent fluorescent lamp 6, which is a lamp, is arranged at a predetermined interval, and a light diffusing and transmitting plate 1, which is a light-transmitting substrate, is placed on one side of the lamp.
3 are arranged to constitute a lighting device.

The above-mentioned bent fluorescent lamp uses a W-shaped cold cathode fluorescent lamp. That is, 7 is a valve bent and formed into a W shape, and this valve 7 is provided with straight portions 8a, 8b, 8C, and 8d that are substantially parallel to each other, and these straight portions 8a, 8b, 8c, and 8d are formed into a U shape. bent part 9a of
, 9b, and 9c are conductive. Cold cathode type electrodes 10a and 10b are sealed at both ends of the bulb 7.
Furthermore, caps 11a and llb are attached to the ends.

Further, a phosphor film (not shown) is formed on the inner surface of the bulb 7, and a predetermined amount of mercury and a starting rare gas such as argon or xenon are sealed inside the bulb 7.

The fluorescent lamp 6 having the above configuration is housed in the gauging 1, and in this case, the straight portions 8a, 8b, 8c of the bulb 7.

8d is installed so as to be substantially parallel to the bottom surface of the casing 1.

Furthermore, caps 11a, 11 at both ends of the fluorescent lamp 6
Part b is formed in the side wall of the casing 1 and has a mounting hole 12. ,.

It is fitted into the casing 1 and fixed to the casing 1 by suitable means such as adhesive.

A light diffusing and transmitting plate 13 is attached to the upper opening of the casing 1 . This light diffusing and transmitting plate 13 is made of a milky white material such as acrylic resin and has a light diffusing and transmitting effect, and the outer surface (or inner surface may be used) of this light diffusing and transmitting plate 13.
A thick portion 14 is formed in a portion facing the valve 7. The thickness of these thick portions 14 gradually becomes thinner as they move away from the valve 7.

A heater 15 is installed on the bottom surface of the gauging 1.

This heater 15 has a heater body 16 covered with heat-resistant insulating films such as polyester resin sheets 17 on both upper and lower surfaces.
18 is laminated.

The heater body 16 has a W-shape along the W-shaped bulb 7 of the cold cathode fluorescent lamp 6, and may be made of nichrome wire, but in the case of this embodiment, a film heater made of metal mesh is used as the W-shape. It is formed by cutting out a shape, or a meandering heater is formed into a W shape. The heat-resistant insulating films 17 and 18 each consist of one continuous film having a larger outline than the outline of the heater main body 16, and are formed into a substantially rectangular shape that does not correspond to the shape of the bottom surface of the gauging l, for example.

Further, in order to maintain insulation between the fluorescent lamp 6 and the heater 15, there is also a space between the fluorescent lamp 6 and the heater 15.
In order to effectively reflect visible light, a white insulating film 2 with a high reflectance is fixed to the heater 15 via an adhesive 4.

The effects of the embodiment with the above configuration will be explained.

When the fluorescent lamp 6 is energized, the lamp 6 emits light in a shape along the W-shaped bulb 7.

A part of the light emitted from the fluorescent lamp 6 is reflected by the side surface of the casing 1 and the insulating film 2 and goes toward the light diffusing and transmitting plate 13 in the opening, and the remaining light goes directly to the diffusing and transmitting plate 13. Almost all of the light emitted from the lamp 6 is irradiated to the outside through the light diffusing and transmitting plate 13.

At this time, a discharge occurs between the electric currents 10a and 10b of the fluorescent lamp 6, and a current also flows through the heater body 16, heating the fluorescent lamp 6.

Since both 6.16 are arranged via the insulating film 2, even if current flows through both 6.16 as described above, no leakage occurs between them.

Because of this, there is no loss of current in the fluorescent lamp 6, and the average brightness does not decrease.

Furthermore, since the insulating film 2 uses a white film, the reflection efficiency of visible light is high, and as a result, the average brightness is increased by 20% compared to the conventional film.

In addition, a thick portion 14 is provided on a part of the surface of the light diffusing and transmitting plate 13.
・As a result, the thick part 14 faces directly above the bulb 7, and the amount of light transmitted through the thick part is reduced. The amount of transmission increases, and therefore, the light diffusing and transmitting plate 13 itself also functions to eliminate uneven brightness.

As detailed above, the brightness distribution on the light diffusing and transmitting plate 13 has uneven brightness both in the direction perpendicular to the straight parts 8a, 81), 8c, and 8d and in the direction along the straight parts 8a, 8b, 8c, and 8d. The brightness can be reduced and the brightness can be made uniform over the entire surface.

Further, in this embodiment, if the heater 15 is energized before starting, the heater 15 generates heat and heats the bulb 7 of the fluorescent lamp 6. Therefore, since the mercury and rare gas inside the bulb 7 are warmed to some extent, it is easier to start the discharge, and after the start of the discharge, the vapor pressure of the mercury and the rare gas is easier to rise to a predetermined pressure, and the luminous flux rises quickly. . In other words, starting characteristics are improved even at low ambient temperatures.

Further, during stable lighting, the fluorescent lamp 6 is heated by the heat generated by the heater 15, and the vapor pressure of mercury or rare gas is maintained at a predetermined pressure, thereby increasing the luminous efficiency.

For this reason, lamp efficiency can be improved even in a low temperature atmosphere.

In addition, the heater 15 is constructed by laminating a W-shaped film-shaped heater body 16 cut out with approximately rectangular heat-resistant insulating films 17 and 18 made of a continuous film each having a larger outline than the outer contour of the heater body 16. Therefore, the W-shaped heater main body 16 can be handled as a substantially rectangular sheet, making the bonding work easier.

Note that the heater 15 may be energized only when the surrounding temperature is particularly low, and therefore the energization of the heater 15 may be controlled by detecting the ambient temperature with a sensor or the like.

Further, a heater may be used to improve the rise even when the surrounding temperature is high, and a heat insulating layer may be provided between the reflector and the heater to speed up the rise in temperature of the heater.

Further, in the case of the above embodiment, the casing 1 is made of synthetic resin such as polycarbonate, but the present invention is not limited to this, and the casing 1 is made of metal such as aluminum, or other materials for high frequency shielding when the lamp is lit at high frequency. It may be made of conductive metal.

[Effects of the Invention] As explained above, according to the present invention, in a lighting device in which a lamp and a heating body for heating the lamp are disposed in a main body having a translucent substrate on one side, the above-mentioned substrate and Since this is a lighting device in which an insulating member that reflects visible light is interposed between the lamp and the heating body, both the lamp and the heating body are
Since they are disposed via an insulating member, even if current flows through both, leakage will not occur between them.

Because of this, there is no loss of current in the lamp, and the average brightness does not decrease.

Furthermore, since the insulating member uses a member with high luminous efficiency, the reflection efficiency of visible light is high, and as a result, the average luminance has increased by about 20% compared to the conventional one.

[Brief explanation of drawings]

1 and 2 show one embodiment of the present invention, with FIG. 1 being an exploded perspective view of the whole, and FIG. 2 being a sectional view. 1...Casing, 2...Insulating film, 6...
Fluorescent lamp, 7-...bulb, 8a, 8b, 1l
lc, 8d--straight section, 9a, 9b, 9cm
・Bending portion, 10a, 10b... Electrode, 13... Light diffusing and transmitting plate, 15... Heater, 16... Heater body, 17.18... Heat resistant insulating film.

Claims (2)

[Claims] (1) In a lighting device in which a lamp and a heating element for heating the lamp are disposed in a main body having a translucent base on one side, an insulating member that reflects visible light is provided between the base and the lamp. A lighting device characterized by intervening. (2) The lighting device according to claim 1, wherein the insulating member is a thin film.