JPH03184204A - Illumination device - Google Patents

Abstract

PURPOSE:To absorb dispersion originating from molding process and deformations due to thermal expansion and contraction by inserting the end of a discharge lamp through a hole in each lamp holder made of an elastic material, supporting the said end by this lamp holder, and pinching this movably by a casing and hold plate for mounting thereto. CONSTITUTION:Between a circuit board 25 and a cover 30, lamp holders 13, 13 are held with a pinching force in such a degree as capable of sliding in the direction of arrow, so that there is no hindrance to mechanically bear the ends 10, 10 of a lamp 7, but this is rather a pinching force which allows sliding of the lamp holders 13, 13. Thereby generation of thermal stresses can be prevented by allowing the lamp holders 13, 13 to slide even in case variation is generated in the distance between the ends 10, 10 of the lamp 7 due to dispersion of the shape when lamps were manufactured or due to thermal expansion and contraction resulting from repeated lighting-up and extinction of the lamp.

Description

[Detailed description of the invention] [Object of the invention] (Industrial application field) The present invention uses a low pressure discharge lamp such as a fluorescent lamp as a light source,
The present invention relates to a lighting device suitable for backlights of liquid crystal televisions and liquid crystal meters.

(Conventional technology) LCD televisions, LCD meters, etc. are designed to illuminate the LCD surface by shining light from the back of the transmissive LCD panel.
Such a backlight requires a device that illuminates a liquid crystal surface having a predetermined spread with uniform brightness as a whole.

This type of backlight has traditionally housed a hot cathode or cold cathode fluorescent lamp in a shallow dish-shaped casing.
A lighting device is used in which the light emitted from the lamp is reflected by a reflective surface formed in a casing and illuminated on the back side of a liquid crystal panel through a light diffusing and transmitting plate installed in an opening of the casing.

When a hot cathode or cold cathode fluorescent lamp is used as a light source, these fluorescent lamps have superior luminous activity and generate less heat than incandescent lamps, have a long life, and have a long discharge path, so their light emitting area is small. It has the advantage that it is large and the light distribution can be easily made uniform. In particular, 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. This is advantageous for illuminating a display surface with uniform brightness.

By the way, when such a bent fluorescent lamp is fixed to the western part of the casing, it is necessary to support the lamp so that it will not be damaged even if vibrations or shocks are applied to the entire device from the outside.

For this reason, a structure is adopted in which the bent portion and both ends of the lamp are supported by a lamp holder made of an elastic material such as silicone rubber.

(Problems to be Solved by the Invention) However, in bent lamps, the relative distance between both ends often varies due to molding variations, heating and cooling distortion during molding, and the like.

Further, after the lamp is assembled into the casing, the distance between the two ends becomes relatively wide due to the heat generated by the lamp during lighting and use, and narrows when the lamp is turned off.

Therefore, if the lamp holder that supports both ends of the lamp is firmly fixed to the casing, it will not be possible to absorb the above-mentioned molding variations, and it will not be possible to absorb the spread or pinching of both ends due to thermal expansion and contraction, causing the bulb to There is a risk that stress will occur and cracks will occur.

For this reason, it is desirable that the lamp holder supporting both ends of the lamp be movably attached to the casing.

However, if the lamp holder is attached so as to be movable relative to the casing, the original lamp supporting function will be impaired. For this reason, the lamp holder can absorb molding variations as well as thermal expansion.

It can absorb the spread and pinching of both ends due to shrinkage, but the lamp must be attached to the casing to support it, and this attachment requires a complicated structure.

The present invention provides a lighting device that can support a lamp holder that supports both ends of a lamp with a simple structure while maintaining the lamp support function and absorbing deformation due to molding variations, thermal expansion, and contraction. That is.

[Structure of the invention] (Means for solving the problem) The first aspect of the present invention is that a lamp holder made of 4+11 material supporting the end of a bent low-pressure discharge lamp is attached to a casing and the casing. It is characterized by being movably clamped with a presser plate.

A second feature of the present invention is that a lamp holder made of an elastic material that supports the end of a bent low-pressure discharge lamp is movably held between a circuit board attached to a casing and a presser plate attached to the casing. shall be.

(Function) In both the first and second aspects of the present invention, the lamp holder made of an elastic material that supports the end of the low-pressure discharge lamp is formed by a casing or a circuit board attached to the casing, and a presser plate attached to the casing. Since it is held by the movable member, it is possible to maintain the lamp support function and absorb deformation due to molding variations, thermal expansion, and contraction. Moreover, this structure is simple as it only requires clamping the lamp holder on +11.
It is t.

(Example) The present invention will be described below based on an example shown in FIGS. 1 to 3.

In the figure, 1 is a casing with an open top surface;
For example, it is made of a metal such as conductive aluminum. This casing 1 has a lamp housing part 2 having a relatively large area on one side, and a circuit board housing part 3 on the other side.

The lamp accommodating portion 2 has a shallow dish shape, and a reflective surface 4 is formed on the inner surface.

The circuit board accommodating part 3 has four topography parts and has a deeper bottom wall than the lamp accommodating part 2.

The upper surface opening of such a casing 1 is used as an irradiation part, and a fixing piece 5 for attaching the casing 1 to the main body chassis of a liquid crystal display device, etc. is formed in this opening, and these fixing pieces 5 ... are formed with mounting holes 6.

A bent fluorescent lamp 7 is accommodated in the casing 1 . The fluorescent lamp 7 of this embodiment is a W-shaped cold cathode fluorescent lamp. That is, 8 is a valve bent into a W-shape, and this valve 8 is provided with substantially parallel straight parts, and these straight parts are U-shaped bent parts 9a.

Qb and Qc are electrically connected. Both ends 10 of valve 8.
A cold cathode type electrode 11.11 is sealed to 10.

A phosphor coating (not shown) is formed on the inner surface of the bulb 8, and a predetermined amount of mercury and a starting rare gas such as argon or xenon are sealed inside the bulb 8.

The fluorescent lamp 7 having such a configuration has both ends 10.10.
is accommodated in the circuit board accommodating section 3, and the other parts are accommodated in the lamp accommodating section 2.

This lamp 7 is then supported by a lamp holder 12, 13, 13.

The lamp holders 12, 13, 13 are made of an elastic material such as white silicone rubber.

One lamp holder 12 is a bulb 8 bent into a W shape.
A recess 1 into which the two U-shaped bent portions 9a and 9b fit.
2a and 12b, and is arranged at the other end of the lamp housing section 2. The lamp holder 12 is held immovably by presser tabs 14 cut and raised from the bottom wall of the lamp accommodating portion 2, and is held between the casing 1 and a light diffusing and transmitting plate 20, which will be described later.

The other two lamp holders 13.13 are fluorescent lamps 7
The insertion hole 13 a s through which both ends 10.10 of the
13 a, these lamp holders 13.13
is accommodated in the circuit board accommodating portion 3 and supported by means described later.

Incidentally, projections 15 are formed on both upper and lower surfaces of these lamp holders 13.13.

A light diffusing and transmitting plate 20 is attached to the open upper surface of the lamp accommodating portion 2 of the casing 1 . This light diffusing and transmitting plate 20 is made of a milky white material such as acrylic resin and has a light diffusing and transmitting effect, and a bulb 8 is provided on the lower surface (or upper surface) of this light diffusing and transmitting plate 20. Thick portions 21 are formed in portions facing each straight portion. The thickness of these thick portions 21 gradually becomes thinner as the distance from the valve 8 increases.

The light diffusing and transmitting plate 20 is fixed to the casing 1 by bending and caulking fixing pieces 22 formed in the opening of the casing 1 so as to cover the upper opening of the lamp accommodating portion 2 . Therefore, the negative lamp holder 12 is held between the bottom wall of the lamp accommodating portion 2 and the light diffusing and transmitting plate 20.

The circuit board accommodating portion 3 of the casing 1 includes a circuit board 2
5 and both ends 10.10 of the fluorescent lamp 7 are accommodated.

Although not shown, the enclosure board 25 has high-frequency lighting circuit components such as an inverter transformer, a capacitor, and a noise filter mounted thereon.

This circuit board 25 is supported by support protrusions 26.26 that project inward from the side wall of the circuit board accommodating portion 3, and support pieces 27.27 formed by cutting and raising the bottom wall of the circuit board accommodating portion 3. The upper surface of the circuit board 25 is placed at approximately the same height as the bottom wall of the lamp accommodating portion 2 .

The circuit board 25 includes fixing tongue pieces 28 and 28 that project inward from the side wall of the circuit board accommodating portion 3;
Two caulking pieces formed at the upper end of the support piece 27 and 27,
It is fixed to the circuit board accommodating part 3 by caulking 29. Note that there are caulking pieces 29 and 29 on the circuit board 25.
A cutout groove 24.24 into which the caulking piece 2 is inserted is formed.
9.29 is inserted through the cutout groove 24.24 and is torsionally deformed.

This circuit board accommodating portion 3 is covered with a cover 30 which corresponds to the holding plate of the present invention.

The cover 30 is formed of a metal plate such as aluminum, and covers only the top opening of the circuit board accommodating portion 3 in the casing 1.

This cover 30 is formed with a partition wall 31 that partitions the lamp accommodating part 2 and the circuit board accommodating part 3, and this partition wall 31 has a notch 32 through which both ends of the lamp 7 pass.
32 is formed. Further, the cover 30 is formed with locking claws 33, 33 on both sides.

This cover 30 is placed over the top opening of the circuit board accommodating part 3 in the casing 1, is supported by a support protrusion 34 formed on the side wall of the circuit board accommodating part 3, and is protruded from the top opening of the circuit board accommodating part 3. The provided hooking claws 35 are engaged with the hooking holes 36 provided in the cover 30,
Further, the cover 30 is fixed to the casing 1 by engaging locking claws 33, 33 provided on both sides of the cover 30 into locking holes 37 formed in the bottom wall of the circuit board accommodating portion 3.

In this case, two lamp holders 13.13 supporting both ends 10.10 of the fluorescent lamp 7 are sandwiched between the circuit board 25 and the cover 30, as shown in FIG. That is, the protrusions 15 formed on both the upper and lower surfaces of the lamp holder 13, 13 are pressed between the cover 30 and the circuit board 25, and are shaped into elastic protrusions.

This provides mechanical support for the two lamp holders 13.13, supporting both ends 10.10 of the lamp 7.

In this case, these lamp holders 13.13 are connected to the bulb 8.
When thermal stress occurs, the circuit board 25 and the cover 30 are held together with such a clamping force that they can be slid, for example, in the direction of the arrow in FIG.

Note that there are holes 39 for heat radiation in the side wall of the circuit board accommodating part 3.
・is formed.

The operation of the embodiment with such a configuration will be explained.

When the fluorescent lamp 7 is electrically connected to the circuit board 25 and high-frequency power is applied to the lamp 7 to light it, the lamp 7
emits light in a shape along the W-shaped bulb 8.

A part of the light emitted from the fluorescent lamp 7 is reflected by the reflective surface 4 of the lamp accommodating part 2 and passes through the light diffusing and transmitting plate 2 of the opening.
0, and the remaining light is directed directly to the light diffusing and transmitting plate 20.
heading to Therefore, almost all of the light emitted from the lamp 7 is irradiated to the outside through the light diffusing and transmitting plate 20.

In this case, thick portions 21, . exists, and this thick part 2'1 reduces the amount of light transmission, and the thick part 2'1
As the distance from 1 increases, the wall thickness decreases and the amount of light transmitted increases. Therefore, the light diffusing and transmitting plate 20 has the effect of eliminating brightness unevenness by itself.

For this reason, the luminance on the light diffusing and transmitting plate 20 is equalized, unevenness in luminance is reduced, and uniform brightness can be achieved over the entire surface.

The bent fluorescent lamp 7 housed in the casing 1 has two U-shaped bent portions 9a.

9b is supported by a lamp holder 12 made of an elastic material, and both ends 10.10 are also supported by lamp holders 13.13 made of an elastic material, so even if vibrations or shocks are applied from the outside, , these lamp holders 12.
13.13, and damage to the lamp 7 is prevented.

In this case, one lamp holder 12 is held between the casing 1 and the light diffusion/transmission plate 20, and is also held down by the presser tabs 14 cut and raised from the bottom wall of the lamp accommodating portion 2. It is immovable, and the support structure of this lamp holder 12 is simple.

Further, the other two lamp holders 13.13 supporting both ends 10.10 of the fluorescent lamp 7 are held between the circuit board 25 and the cover 30.

In this case, the lamp holders 13, 13 are held down between the circuit board 25 and the cover 30 with such a clamping force that they can be slid, for example, in the direction of the arrow in FIG. There is no problem in mechanically supporting the lamp holder 13.10.
3 has enough clamping force to be able to slide, so it is easy to manufacture lamps.
! If the distance between the two ends 10 and 10 of the lamp 7 changes due to variations in the shape of the lamp I or thermal expansion or contraction due to repeated lamp turning on and off, these lamp holders 13
．． The sliding movement of 13 can prevent the generation of thermal stress.

Therefore, cracks will not occur in the valve 8.

Note that since the lamp holders 13.13 are made of an elastic material, the stress of the bulb can be absorbed by the elastic deformation of these lamp holders 13.13, but any stress beyond that can be absorbed by the lamp holders 13.13. It is something that is absorbed through movement.

Moreover, in order to slidably hold these lamp holders 13.13, the structure is such that the lamp holders 13.13 are simply held between the circuit board 25 and the cover 30, and the supporting structure of the lamp holders 13.13 is extremely simple. It doesn't take much effort.

The present invention is not limited to the above embodiments.

That is, in the above embodiment, the lamp holder 13.13 is held between the cover 30 and the circuit board 25, but in the case of a lighting device that does not include the circuit board 25,
As shown as a modification in FIG. 4, the lamp holder 13.1
3 may be held between the casing 1 and the cover 30.

In addition to the W-shape, the fluorescent lamp may have a U-shape, a straight tube shape, etc., and one or a plurality of fluorescent lamps may be used.

Furthermore, the present invention may be a rare gas discharge lamp in which the bulb is not filled with mercury but only with a rare gas.

Further, the lamp is not limited to one that is lit at a high frequency.

Furthermore, the lamp holder is not limited to being pressed by the cover, but may be pressed by a light diffusing and transmitting plate, or may be pressed by another holding plate.

[Effects of the Invention] As explained above, according to the first and second aspects of the present invention, a lamp holder made of an elastic material supporting an end of a low-pressure discharge lamp includes a casing or a circuit board attached to the casing; Since it is movably held between the presser plate attached to the casing, it is possible to absorb molding variations and deformation due to thermal expansion and contraction while maintaining the lamp supporting function. Furthermore, since this structure simply involves holding the lamp holder between the casing or the circuit board attached to the casing and the holding plate attached to the casing, the structure is in the cylinder, and no particularly complicated parts are required for assembly. It doesn't require any effort.

[Brief explanation of drawings]

1 to 3 show one embodiment of the present invention, in which FIG. 1 is an exploded perspective view of the whole, FIG. 2 is a plan view with a part of the light diffusing and transmitting plate cut away, and FIG. 2 is a sectional view taken along the line ■--■ in FIG. 2, and FIG. 4 is a sectional view showing another embodiment of the present invention.

Claims (2)

[Claims] (1) In a lighting device in which a low-pressure discharge lamp is housed in a casing with an irradiation part provided on one side, and the light emitted from the discharge lamp is irradiated from the irradiation part of the casing, the end of the discharge lamp The lamp holder is supported by the lamp holder by passing through an insertion hole formed in the lamp holder made of an elastic material, and the lamp holder is movably held between the casing and a presser plate attached to the casing. lighting equipment. (2) A lighting device characterized in that a lamp holder made of an elastic material that supports an end of the low-pressure discharge lamp is movably held between a circuit board attached to the casing and a presser plate attached to the casing. .