JP4430993B2 - Backlight device and liquid crystal display device - Google Patents

Description

  The present invention relates to a lamp holder, a backlight device, and a liquid crystal display device used in a liquid crystal display device.

  With the increase in the size of non-light-emitting displays such as liquid crystal displays, it is inevitable that the fluorescent tube used for the backlight will be long.

  In addition, since the fluorescent tube has a higher luminous efficiency as the tube inner diameter is smaller, it is desirable to make it thinner than a long tube, and the mechanical strength (particularly against bending) of the fluorescent tube alone is very weak. Become.

  In particular, when considering a direct-type backlight, the fluorescent tube is usually positioned using a rubber holder that insulates the solder joint between the lead wire from the fluorescent tube electrode and the power circuit harness. When the fluorescent tube is bent and bent, it causes a large luminance unevenness, and in the worst case, the fluorescent tube is destroyed.

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

  Various proposals have been made for a fluorescent tube holder structure of a backlight device used in a liquid crystal display device or the like, but there are many proposals for a small liquid crystal display device, and the fluorescent tube holder for a small liquid crystal display device has a short tube length. Basically, the method of supporting only the vicinity of both ends of the fluorescent tube, or the method of supporting the whole and having an opening only in the light irradiation direction, and the method for supporting the intermediate portion of the fluorescent tube, are proposals for lighting fixtures. Is helpful.

  JP-A-9-115326 (Patent Document 1) and JP-A-10-326516 (Patent Document 2) are disclosed as proposals for this type of fluorescent tube holder.

  In Patent Document 1, there is a fluorescent lamp holder that is flexible and has a fluorescent lamp holder that is gripped and attached to a partially-circular grip ring material that has an opening in a part thereof. A plurality of locking tools that engage with the locking holes provided in the mounting body are provided by shifting the locking tools in the circumferential direction of the grip ring, thereby engaging 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 removal when the fluorescent lamp is taken out of the fluorescent lamp holder by appropriately selecting and using the locking tool, so that the fluorescent lamp and the fluorescent lamp holder can be attached and detached without damage. It is.

In patent document 2, it consists of the reflecting plate for raising illuminance, and the fixture for attaching this reflector to the tube part of a fluorescent lamp, and the fixture has a first boss having a head and a neck, A second boss having a height lower than that of the boss and a holder portion for fitting and fixing the tube portion of the fluorescent lamp; and the reflector includes an insertion portion and a neck portion for inserting the head portion of the first boss A first hole having a retaining portion for engaging and holding the fixture; and when the first boss is inserted into the first hole and then moved to engage the neck, the second boss is received. The second reflector hole is provided to fix the fixture to the reflector, so that it is easy to mount and adjust, and the reflector assembly for a fluorescent lamp is proposed.
JP-A-9-115326 JP-A-10-326516

  As described above, also in the liquid crystal display device, at least one or two fluorescent tube intermediate portions are provided 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 an increase in size. It is necessary to support at a point, and a lamp holder having a shape including Patent Document 1, Patent Document 2, and the like is required.

  Due to the lengthening and narrowing of the fluorescent tube of the backlight device, and in addition to the increase in the number of tubes, the variation in the position 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 has to be in contact with the fluorescent tube in some form, and there is a problem that some luminance unevenness occurs at that portion, and the conventional lamp holder mainly prevents the destruction of the fluorescent tube. In addition to this, it is necessary to consider the display quality by the lamp holder itself and its arrangement method.

In the present invention, in a direct type backlight device having a plurality of fluorescent tubes arranged in a single row so that their longitudinal directions are substantially the same direction, and support portions that support the vicinity of both ends of the fluorescent tubes A plurality of transparent lamp holders for supporting the fluorescent tubes between the support portions, and the lamp holders adjacent to the arrangement direction of the plurality of fluorescent tubes are arranged so that the positions in the longitudinal direction of the fluorescent tubes are different. It is characterized by that.
Specifically, the lamp holders may be arranged in a staggered manner.

The liquid crystal display device includes the direct type backlight device and a liquid crystal panel.

It is preferable that the lamp holder includes a protrusion that protrudes closer to the liquid crystal panel than the plurality of fluorescent tubes.

According to the present invention, not only the vicinity of both ends of a fluorescent tube used in a liquid crystal display device is supported, but also an intermediate portion of the fluorescent tube is held by a lamp holder formed of a transparent member, thereby Even if the fluorescent tube becomes longer or narrower with an increase in size, it is possible to prevent the fluorescent tube from being damaged and uneven brightness due to the deflection of the fluorescent tube, and to maintain the performance and quality of the apparatus. In addition, since the lamp holder is formed of a transparent member, even when the intermediate portion of the fluorescent tube is held by a large liquid crystal display device, a decrease in luminance of the light source can be minimized.
And since the slight influence on the optical path by the lamp holder is not concentrated on a specific part, the quality with respect to luminance unevenness is improved.

  As an embodiment of the present invention, a direct 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 / side view of the periphery of the liquid crystal panel and the backlight device. In FIG. 1, 1 is a fluorescent tube, 2 is a lamp holder, 3 is a reflector, 4 is a fluorescent tube support, 5 is a diffuser, and 6 is a liquid crystal panel. The reflector 3, the fluorescent tube support 4, the lamp holder mounting hole, and the substrate mounting boss (not shown) are formed by integral molding.

In addition, the lamp holder 2 has a partially circular fluorescent tube grip shape having an opening in a part thereof, and is made of a transparent acrylic material having flexibility.
FIG. 2 is a view showing the relationship between the lamp holder and the reflector, and FIG. 3 is a view showing how the lamp holder is attached.
In FIG. 3, reference numeral 7 denotes a substrate on which device driving circuit components arranged on the back side of the reflector 3 are mounted, and 8 denotes a screw.

  As shown in FIG. 2, the assembling method of 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 attached to the fluorescent tube support 4 and the lamp holder 2. In addition, the lead is pulled out from the fluorescent tube electrode lead extraction hole formed on the side surface of the reflecting plate 3, and the fluorescent tubes 1 are mounted while being adjusted so that they are in the center position in the reflecting plate 3.

  In front of the backlight, the diffusion plate 5 and the liquid crystal panel 6 are arranged and fixed at a predetermined interval. The electrode lead of the fluorescent tube 1 is soldered to a backlight drive power supply 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 driving voltage from the liquid crystal driving power supply circuit under the control of the control circuit mounted on the substrate 7, and the direct light of the emitted light and the reflecting plate 3 are turned on. Reflected light reaches the diffusion plate 5 and is diffused to uniformly irradiate the back surface of the liquid crystal panel 6.

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

  In this way, by adopting the lamp holder 2, it is possible to protect against destruction due to deformation of the fluorescent tube 1, to ensure the positional accuracy of the fluorescent tube 1 array and prevent luminance unevenness on the information display surface, and By using the lamp holder 2, it is possible to prevent the luminance of the information display surface from being affected by the shade of the lamp holder 2 and the influence on the luminance unevenness.

  Since the liquid crystal display device is required to be thin, the spatial distance between the reflective plate 3 and the heat generating component disposed on the substrate 7 or the like is close, and the resin reflective plate 3 is warped under the influence of the heat generating component. (And warping also appears depending on the molding conditions of the reflector 3).

  When the lamp holder 2 is fixed to a part that is deformed in this way, the absolute position of the lamp holder 2 is shifted in a manner that is affected by the deformation, and the fluorescent tube 1 is bent, which also has adverse effects such as uneven brightness and destruction of the fluorescent tube. Therefore, it is possible to make the lamp holder 2 in the shape as shown in FIG.

  Further, there is a case where a metal is used for the reflection plate 3, and a leak current is generated due to a delicate distance between the fluorescent tube 1 and the reflection plate 3, so that the fluorescent tube 1 is lit one side and luminance unevenness occurs. 1 is stressed and bent in the direction of the reflecting plate 3, so that a single lighting can be prevented if a sufficient distance is secured. Therefore, the insulation distance is secured by the thickness of the base portion of the lamp holder 2. It is also possible.

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

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

The method for assembling the backlight and the operation of the display device are the same as those in the first embodiment, and a description thereof is omitted.
In the direct type backlight, the diffusion plate 5 is usually arranged by opening a space of several tens of millimeters from the fluorescent tube 1 toward the screen direction.

  Acrylic or the like is used as the material of the diffusion plate 5 and is very sensitive to thermal expansion. When there is a temperature difference between the front and back of the diffusion plate 5, the temperature is warped in the higher direction. When used in a backlight, it is warped in the direction of the fluorescent tube 1 and this also causes uneven brightness.

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

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

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

  6 and 7 are examples of lamp holder arrangement according to the present invention, and FIGS. 8 and 9 are examples of lamp holder arrangements that may affect display quality.

  Even in the case where a transparent lamp holder as in the present invention is used in a backlight device having a plurality of fluorescent tubes, there is a slight effect on light dispersion and a decrease in the amount of light. When the lamp holder 2 is arranged at a position adjacent to the fluorescent tube 1 as in FIG. 9 or when the in-line type lamp holder 10 for holding all the tubes is used, the assembly work is simplified, When the slight influence on the optical path is concentrated on a specific portion, luminance unevenness and luminance decrease.

  In the present invention, the mounting positions of the lamp holders 2 and 9 are arranged so as not to overlap at the positions adjacent to the longitudinal direction of the fluorescent tubes, or are staggered with respect to the direction in which the fluorescent tubes 1 are arranged as shown in FIGS. This is a method that further improves the quality against luminance unevenness by not concentrating a slight influence on the optical path by the lamp holder on a specific portion.

  As described above, the lamp holder according to the present embodiment is a lamp holder such as a fluorescent tube disposed on the reflector in the backlight device of the liquid crystal display device, and the lamp holder has an opening in a part thereof. It is made of a transparent member having a chip-like grip shape and having flexibility.

  Further, the lamp holder according to the present embodiment has a plurality of lamp hold portions and is integrally molded.

  In addition, the lamp holder according to the present embodiment is formed by forming a protrusion on the lamp hold side to have a gap with a diffusion plate or a light guide plate arranged in front of the fluorescent tube.

  In addition, the backlight device according to the present embodiment is a backlight device having a plurality of fluorescent tubes, and the mounting position of the lamp holder is arranged so as not to overlap with the longitudinal direction of the fluorescent tubes. It is.

  Further, the backlight device according to the present embodiment is a backlight device having a plurality of fluorescent tubes, and the mounting positions of the lamp holders are arranged in a staggered manner with respect to the arrangement direction of the fluorescent tubes.

  The present invention can be used in a non-luminous display such as a liquid crystal display.

It is a front, a section, and a side view of a backlight and a liquid crystal display unit of an embodiment of the present invention. It is a lamp holder mounting view of an embodiment of the present invention. It is a lamp holder attachment figure of embodiment of this invention. It is a lamp holder mounting view of an embodiment of the present invention. It is a lamp holder mounting view of an embodiment of the present invention. It is a lamp holder arrangement drawing of an embodiment of the present invention. It is a lamp holder arrangement drawing of an embodiment of the present invention. It is a lamp holder arrangement example figure. It is a lamp holder arrangement example figure.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fluorescent tube 2 Lamp holder 3 Reflector 4 Fluorescent tube support part 5 Diffuser plate 6 Liquid crystal panel 7 Substrate 8 Screw 9 Lamp holder for 2 tubes

Claims (4)

In a direct type backlight device having a plurality of fluorescent tubes arranged in a row so that the longitudinal direction is substantially the same direction, and a support portion that supports the vicinity of both ends of the fluorescent tubes,
A plurality of transparent lamp holders that support the fluorescent tube between the support parts,
The direct-type backlight device, wherein the lamp holders adjacent to each other in the arrangement direction of the plurality of fluorescent tubes are arranged so that positions in the longitudinal direction of the fluorescent tubes are different. The direct-type backlight device according to claim 1, wherein the lamp holders are arranged in a staggered manner. A liquid crystal display device comprising the direct type backlight device according to claim 1 and a liquid crystal panel. The liquid crystal display device according to claim 3, wherein the lamp holder includes a protrusion that protrudes closer to the liquid crystal panel than the plurality of fluorescent tubes.

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