JP2001210126A - Lamp holder and back light device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an improved lamp holder by solving such a problem that one or two points are required to support middle part of a fluorescence tube at least to maintain performance and quality of a device due to the fact that the fluorescence tube in the back light is getting longer and slimmer by getting larger in size for LCD display. SOLUTION: By employing the lamp holder which is formed in a segmented gripping shape having an opening in one part, made of a transparent material having flexibility, and integrally formed for a single tube and multiple tubes, the fluorescent tube is protected and also the positional accuracy of the fluorescent tube array is secured to prevent luminance unevenness of information display surface, and at the same time the luminance degradation of information display surface due to the shade of the lamp holder and the effect to the luminance unevenness can be prevented by using transparent materials.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backlight device used for a liquid crystal display device.

[0002]

2. Description of the Related Art As a non-light emitting display such as a liquid crystal display becomes larger, it is inevitable that a fluorescent tube used for the backlight is elongated.

Further, since the fluorescent tube has a smaller luminous efficiency as the tube inner diameter is smaller, it is desired to make the fluorescent tube thinner in addition to the longer tube, and the mechanical strength of the fluorescent tube alone (particularly against bending) is very high. It will be weak.

[0004] Especially when considering a direct backlight,
Normally, the fluorescent tube is positioned using a rubber holder that insulates the solder joint between the lead wire from the fluorescent tube electrode and the power supply circuit harness. It is a major cause of unevenness, and in the worst case, it causes destruction of the fluorescent tube.

In order to prevent this phenomenon, a positioning mechanism (lamp clip) is usually used at one or two points in the length direction of the fluorescent tube.

Various proposals have been made for the structure of a fluorescent tube holder portion of a backlight device used for a liquid crystal display device or the like, but many proposals have been made for a small liquid crystal display device, and the fluorescent tube holder for a small liquid crystal display device has a tube length. In general, a method of supporting only the vicinity of both ends of the fluorescent tube or a method of supporting the entirety and having an opening only in the light irradiation direction is mainly used. Suggestions on equipment will be helpful.

Japanese Patent Application Laid-Open Nos. Hei 9-115326 and Hei 10-326516 propose a fluorescent tube holder of this type.
Publication No. JP-A-2005-115122 is disclosed.

[0008] Japanese Patent Application Laid-Open No. Hei 9-115326 discloses a fluorescent lamp holder which has flexibility and is configured to grip and attach a fluorescent lamp to a partially circular holding ring material having an opening in a part thereof. , On the outer peripheral surface of the grip ring,
By providing a plurality of locking tools that engage with the locking holes provided in the mounting body and displaced in the circumferential direction of the holding ring, a plurality of locking tools that engage with the locking holes provided in the mounting body depending on the fluorescent lamp mounting location. Proposal that the user can select the direction of taking out the fluorescent lamp from the fluorescent lamp holder by selecting and using the appropriate fasteners, so that the fluorescent lamp and the fluorescent lamp holder can be attached and detached without damage. is there.

In Japanese Patent Application Laid-Open No. 10-326516, a reflector is provided for increasing the illuminance, and a fixture for attaching the reflector to a tube portion of a fluorescent lamp. A first boss having a first boss, a second boss having a height lower than the boss, and a holder for fitting and fixing the tube of the fluorescent lamp, and the reflecting plate holds the head of the first boss. A first hole having an insertion portion to be inserted and a holding portion that engages with the neck to hold the fixture;
And a second hole provided to receive the second boss when it is moved into engagement with the neck after being inserted into the hole, and to fix the fixture to the reflector.・ We propose a reflector assembly for fluorescent lamps that is easy to adjust and easy to handle.

[0010]

As described above, in order to maintain the performance and quality of the liquid crystal display device in order to maintain the performance and quality of the device in response to the lengthening and narrowing of the fluorescent tube of the backlight device accompanying the enlargement of the liquid crystal display device. It is necessary to support the tube intermediate portion at at least one or two points, and a lamp holder having a shape as disclosed in Japanese Patent Application Laid-Open Nos. 9-115326 and 10-326516 is required.

[0011] By increasing the length and the size of the fluorescent tube of the backlight device and increasing the number of tubes, the positional variation of the fluorescent tube may cause uneven brightness on the display screen, and the fluorescent tube moves in all directions. In order to prevent this, the lamp holder must be in some way in contact with the fluorescent tube, and there is a problem that a slight brightness unevenness occurs in that part.
In addition to the conventional concept of the lamp holder mainly for preventing the destruction of the fluorescent tube, it is necessary to further consider the display quality by the lamp holder itself and its arrangement method.

[0012]

According to the first and second aspects of the present invention, a one-pipe or multi-piece structure is made of a transparent member having a partially circular grip shape having an opening at a part thereof and having flexibility. By adopting a lamp holder integrally molded for the tube, it protects the fluorescent tube, secures the positional accuracy of the fluorescent tube arrangement, prevents luminance unevenness on the information display surface, and uses a transparent material to make the lamp holder It is possible to prevent the shadow from affecting the brightness of the information display surface and the uneven brightness due to the shadow.

According to the third aspect of the present invention, a projection is provided on the lamp hold side for providing a space between a diffusion plate or a light guide plate disposed in front of the fluorescent tube, so that the fluorescent tube / reflection plate and the diffusion plate are formed. Or a light guide plate, thereby preventing luminance unevenness on the information display surface.

According to the fourth and fifth aspects of the present invention, in the backlight device having a plurality of fluorescent tubes, the mounting position of the lamp holder is arranged so as not to overlap at a position adjacent to the fluorescent tube in the longitudinal direction. By arranging the fluorescent tubes in a staggered manner in the direction in which the fluorescent tubes are arranged, it is possible to further improve the quality with respect to luminance unevenness by preventing the slight influence of the lamp holder on the optical path from being concentrated on a specific portion.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As an embodiment of the present invention, a direct type backlight device of a liquid crystal display device will be described with reference to FIGS.

A first embodiment will be described with reference to FIGS.

FIG. 1 is a front and side view of the periphery of a liquid crystal panel and a backlight device. In FIG. 1, 1 is a fluorescent tube, 2
Is a lamp holder, 3 is a reflection plate, 4 is a fluorescent tube support, 5 is a diffusion plate, and 6 is a liquid crystal panel. The reflector 3, the fluorescent tube support 4, the lamp holder mounting hole, and the board mounting boss (not shown) are integrally formed.

The lamp holder 2 has a shape of a partially circular fluorescent tube having an opening in a part thereof and is made of a transparent acrylic material having flexibility.

FIG. 2 is a diagram showing the relationship between the lamp holder and the reflector, and FIG. 3 is a diagram showing the state of attachment of the lamp holder.

In FIG. 3, reference numeral 7 denotes a substrate on the rear side of the reflection plate 3 on which device driving circuit components are mounted, and 8 denotes a screw.

As shown in FIG. 2, the method of assembling the backlight is such that the bushing-shaped portion of the lamp holder 2 is mounted and fixed in a predetermined mounting hole of the reflector 3, and the six fluorescent tubes 1 are connected to the fluorescent tube support 4 and the lamp. According to the holder 2, a lead is drawn out from a fluorescent tube electrode lead drawing hole formed on the side surface of the reflection plate 3,
Each fluorescent tube 1 is mounted while being adjusted so as to be at the center position in the reflector 3.

A diffusion plate 5 and a liquid crystal panel 6 are arranged and fixed at a predetermined interval in front of the backlight. Fluorescent tube 1
Are soldered to a backlight drive power output unit mounted on the substrate 7.

In the figure, when the liquid crystal display device is operated, the fluorescent tube 1 is turned on by the drive voltage from the liquid crystal drive power supply circuit under the control of the control circuit mounted on the substrate 7, and the direct light of the emitted light is The light reflected by the reflector 3 is diffused by the diffuser 5
, And is diffused to uniformly irradiate the rear surface of the liquid crystal panel 6.

The liquid crystal panel is also driven by the liquid crystal driving circuit, and a clear image is displayed by the backlight.

By employing the lamp holder 2 as described above, the fluorescent lamp 1 is protected from destruction and the like due to deformation, the positional accuracy of the fluorescent lamp 1 array is ensured, and the luminance unevenness on the information display surface is prevented. By using the lamp holder 2 made of a transparent material, it is possible to prevent the shadow of the lamp holder 2 from lowering the brightness of the information display surface and affecting the brightness unevenness.

Since the liquid crystal display device is required to be thin, the spatial distance between the reflection plate 3 and the heat-generating components disposed on the substrate 7 and the like is short, and the reflection plate 3 made of resin is affected by the heat-generating components. 3 is warped (also warps depending on the molding conditions of the reflector 3).

When the lamp holder 2 is fixed to a part which deforms as described above, the absolute position of the lamp holder 2 shifts in a form affected by the deformation, and the fluorescent tube 1 is bent, which also causes uneven brightness and destruction of the fluorescent tube. In order to have an adverse effect such as described above, it is also possible to adopt a method in which the lamp holder 2 is shaped as shown in FIG. 3 and screws 8 are fixed to a substrate 7 disposed on the back surface of the reflection plate 3.

There is also a case where a metal is used for the reflector 3 or the like, and a leak current is generated due to a delicate distance between the fluorescent tube 1 and the reflector 3 so that the fluorescent tube 1 is turned on one-sidedly, causing uneven brightness. Even if the fluorescent tube 1 is stressed and bent in the direction of the reflecting plate 3, it is possible to prevent one-sided lighting if a sufficient distance is provided. Therefore, the insulation distance is determined by the thickness of the base portion of the lamp holder 2. It is also possible to secure

Referring to the second embodiment of the present invention, FIGS.
It is explained together with.

FIG. 4 is a side view of the periphery of the liquid crystal panel and the backlight device. In FIG. 4, reference numeral 9 denotes a lamp holder for two tubes, which has a projection at the center between the fluorescent tube 1 holding portions as shown in the detailed view of FIG.

The method of assembling the backlight and the operation of the display device are the same as those of the first embodiment, and the description is omitted.

In the direct backlight, a diffusion plate 5 is usually arranged with a space of several tens of mm from the fluorescent tube 1 toward the screen.

The material of the diffusion plate 5 is made of acrylic or the like, and is very sensitive to thermal expansion. If there is a temperature difference between the front and back of the diffusion plate 5, the temperature of the diffusion plate 5 becomes higher. When used in a direct-type backlight, it warps in the direction of the fluorescent tube 1, which also causes uneven brightness.

Therefore, as shown in FIG. 4, it is possible to maintain the distance from the diffusion plate 5 by the projection at the intermediate portion of the lamp holder 9 and suppress luminance unevenness.

That is, the lamp holder 9 has both functions of preventing the bending of the fluorescent tube 1 and preventing the diffusion plate 5 from warping.

A third embodiment of the present invention will be described with reference to FIGS.

FIGS. 6 and 7 show examples of the arrangement of the lamp holder of the present invention, and FIGS. 8 and 9 show examples of the arrangement of the lamp holder which may affect the display quality.

In a backlight device having a plurality of fluorescent tubes, even if a transparent lamp holder as in the present invention is used, a slight influence on light dispersion and light quantity reduction can be considered. 8 and FIG.
When the lamp holder 2 is arranged at a position adjacent to the above, or when the in-line type lamp holder 10 for holding the whole tube is used, even if the assembling operation is simplified, the influence of the lamp holder on the optical path is slight. By focusing on certain parts,
Luminance unevenness and luminance decrease.

In the present invention, the mounting positions of the lamp holders 2 and 9 are arranged so that they do not overlap each other in the longitudinal direction of the fluorescent tube, or in the direction in which the fluorescent tubes 1 are arranged as shown in FIGS. On the other hand, by arranging in a staggered manner, a slight influence on the optical path by the lamp holder is not concentrated on a specific portion, thereby further improving the quality with respect to luminance unevenness.

[0040]

According to the first and second aspects of the present invention, a one-tube or multi-tube type is integrally formed with a transparent transparent member which has a partially circular grip shape having an opening part and is made of a flexible transparent member. The adoption of a molded lamp holder protects the fluorescent tubes, secures the positional accuracy of the fluorescent tube arrangement, prevents luminance unevenness on the information display surface, and uses a transparent material to provide information due to the shadow of the lamp holder. It is possible to prevent a reduction in luminance of the display surface and an effect on luminance unevenness.

According to a third aspect of the present invention, a projection is formed on the lamp hold side so as to have a distance from a diffusion plate or a light guide plate disposed in front of the fluorescent tube, so that the diffusion tube and the reflection plate can be diffused. It is possible to secure a space between the light guide plate and the light guide plate, thereby preventing luminance unevenness on the information display surface.

According to the fourth and fifth aspects of the present invention, in the backlight device having a plurality of fluorescent tubes, the mounting position of the lamp holder is arranged so as not to overlap at a position adjacent to the longitudinal direction of the fluorescent tubes. By arranging the fluorescent tubes in a staggered manner with respect to the direction in which the fluorescent tubes are arranged, it is possible to further improve the quality with respect to luminance unevenness by preventing the slight influence of the lamp holder on the optical path from being concentrated on a specific portion.

[Brief description of the drawings]

FIG. 1 is a front, cross-sectional, and side view of a backlight and a liquid crystal display unit according to an embodiment of the present invention.

FIG. 2 is a lamp holder mounting diagram of the embodiment of the present invention.

FIG. 3 is a view showing a lamp holder according to the embodiment of the present invention;

FIG. 4 is a view showing a lamp holder mounted according to the embodiment of the present invention.

FIG. 5 is a view showing a lamp holder mounted according to the embodiment of the present invention.

FIG. 6 is a layout diagram of a lamp holder according to the embodiment of the present invention.

FIG. 7 is a layout view of a lamp holder according to the embodiment of the present invention.

FIG. 8 is an example of a lamp holder arrangement.

FIG. 9 is a diagram illustrating an example of a lamp holder arrangement.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fluorescent tube 2 Lamp holder 3 Reflector 4 Fluorescent tube support 5 Diffusion plate 6 Liquid crystal panel

Claims (5)

[Claims] 1. A lamp holder, such as a fluorescent tube, disposed on a reflector in a backlight device of a liquid crystal display device, wherein the lamp holder has a partially-circular grip shape having an opening in a part thereof. A lamp holder characterized by being made of a transparent member having flexibility. 2. The lamp holder according to claim 1, wherein the lamp holder has a plurality of lamp holding portions and is integrally molded. 3. The lamp holder according to claim 1, wherein a projection is formed on the lamp hold side so as to have an interval with a diffusion plate or a light guide plate disposed in front of the fluorescent tube. 4. A backlight device having a plurality of fluorescent tubes, wherein the mounting positions of the lamp holders according to the first, second and third aspects are arranged so as not to overlap at adjacent positions in the longitudinal direction of the fluorescent tubes. Backlight device characterized. 5. A backlight device having a plurality of fluorescent tubes, wherein the mounting positions of the lamp holders according to claim 1, 2 and 3 are arranged in a staggered manner in the direction in which the fluorescent tubes are arranged. Light device.