JP2008241777A - Liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display device which reduces the occurrence of chatter noise, squeak noise, or the like. <P>SOLUTION: The liquid crystal display device includes a liquid crystal display panel and a backlight disposed on the back of the liquid crystal display panel, and the backlight comprises a plurality of bar-shaped light sources provided in parallel within a plane facing the liquid crystal display panel and a base which supports respective bar-shaped light sources in their electrode parts through electrode metal fittings, and electrode metal fittings supporting the electrode parts of each bar-shaped light source are connected to a connection part extending in the direction where the bar-shaped light sources are provided in parallel, and connection parts are fixed to the base through at least an adhesive. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a liquid crystal display device, and more particularly to a liquid crystal display device including a so-called direct type backlight.

  As the liquid crystal display device has been increasing in size, liquid crystal display devices have been used as direct-type backlights that can make the planar light source uniform.

  In such a backlight, a plurality of fluorescent tubes are juxtaposed in a direction perpendicular to the longitudinal direction in a plane facing the liquid crystal display panel of a base having a light reflecting function. It is configured to be supported by the base via electrode fittings held between the electrode portions at both ends.

  In addition, the electrode fittings sandwiched between, for example, the plus electrode on one end side of each fluorescent tube are configured to be connected in common, and the electrode fittings sandwiched between the minus electrode on the other end side are also configured. Each is configured to be connected in common.

  For this reason, each of the electrode fittings commonly connected to each other is provided on an electrode support material made of a strip-shaped conductive material that extends relatively long in the direction in which the fluorescent tubes are juxtaposed.

A liquid crystal display device having such a backlight is disclosed in, for example, Patent Document 1 below.
JP 2005-347259 A

  However, in the liquid crystal display device configured as described above, when the electrode support material is fixed to the base side, the reliability of the fixing itself must be improved, as a matter of course. There is a demand for a fixing structure that reduces the squeak or chatter noise caused by the noise.

  That is, since the electrode support material is made of a relatively long strip-shaped conductive material as described above, the degree of expansion due to heat from the fluorescent tube is increased, and tentatively, the electrode support material has several points along its longitudinal direction. When it fixes to the base side (for example, three or more places), the bending | flexion which liberates from the base side will generate | occur | produce in the electrode support material between those fixed parts.

  For this reason, the number of fixing of the electrode support material to the base side is reduced, so that the part of the electrode support material which is not fixed is contacted by another member formed separately from the base (for example, (Alternatively, attempts are being made to press). However, when the electrode support member is stretched due to thermal expansion, there is a disadvantage that a squeak noise is generated between the other members.

  Therefore, an attempt has been made to arrange the other members slightly apart from the electrode support material so that the electrode support material is not separated too much from the base side. When it vibrates by the above, etc., it comes into contact with the other member, and there arises an inconvenience that a roaring sound is generated.

  An object of the present invention is to provide a liquid crystal display device in which generation of squeak noise or chatter noise is reduced.

   Of the inventions disclosed in this application, the outline of typical ones will be briefly described as follows.

(1) A liquid crystal display device according to the present invention includes, for example, a liquid crystal display panel and a backlight disposed on the back surface of the liquid crystal display panel.
The backlight is composed of a plurality of rod-shaped light sources arranged in parallel in a plane facing the liquid crystal display panel, and a base that supports each of the rod-shaped light sources via electrode fittings at the electrode portions thereof,
The electrode fittings are configured to support the corresponding electrode portions of each rod-shaped light source, connected to a connection portion extending in the juxtaposition direction of the rod-shaped light sources,
The connection portion is fixed to the base side through at least an adhesive.

(2) The liquid crystal display device according to the present invention is, for example, on the premise of the configuration of (1), wherein the adhesive is made of a double-sided tape extending along the longitudinal direction of the connecting portion.

(3) The liquid crystal display device according to the present invention is based on, for example, the configuration of (1), and the connection portion is fixed to the base side via a screw at one end side thereof.

(4) The liquid crystal display device according to the present invention is, for example, on the premise of the configuration of (1), wherein the connecting portion is fixed to the base side via screws at both ends thereof.

(5) The liquid crystal display device according to the present invention is based on, for example, the configuration of (1), and the connection portion includes a pair of connection portions that connect the electrode fittings at both ends thereof, and the base The adhesive for fixing to the side is provided in each of the connection portions.

(6) The liquid crystal display device according to the present invention is based on, for example, the configuration of (1), and the connection portion includes a pair of connection portions that connect the electrode fittings at both ends thereof, and the base The adhesive for fixing to the side is provided so as to be interposed in one of the connecting portions.

(7) The liquid crystal display device according to the present invention is based on, for example, any one of the configurations (5) and (6), and the base is connected to one end of one of the connecting portions via a screw. It is fixed to the side.

(8) The liquid crystal display device according to the present invention is premised on, for example, the configuration of (5) or (6), and the above-described connection portions are respectively connected to both ends of one connection portion via screws. It is fixed to the base side.

  In addition, this invention is not limited to the above structure, A various change is possible in the range which does not deviate from the technical idea of this invention.

  The liquid crystal display device configured as described above can reduce the occurrence of squeak noise, chatter noise, or humming.

  Hereinafter, embodiments of a liquid crystal display device according to the present invention will be described with reference to the drawings.

  FIG. 2 is a schematic configuration diagram showing an embodiment of the liquid crystal display device according to the present invention.

  First, the liquid crystal display panel PNL, the optical sheet OS, and the backlight BL are sequentially arranged from the observer side.

  The liquid crystal display panel PNL includes a pair of parallelly arranged substrates SUB1 and SUB2 made of glass, for example, as an envelope, and liquid crystal is interposed between the substrates SUB1 and SUB2.

  Pixels (not shown) arranged in a matrix are formed on the surface of the substrates SUB1 and SUB2 on the liquid crystal side as a component of the liquid crystal, and the light transmittance of the liquid crystal can be controlled for each of these pixels. It is like that.

  Then, an area in which these pixels are formed is defined as a liquid crystal display area AR (area surrounded by an alternate long and short dash line frame in the figure), and light from a backlight BL described later is irradiated over the entire area of the liquid crystal display area AR. The viewer is made to recognize the image through light transmitted through the pixels.

  Note that the substrate SUB1 disposed behind the observer side has a larger area than the substrate SUB2, and a semiconductor including a circuit for independently driving each pixel is exposed around the substrate SUB2. A device SCD is mounted.

  On the back surface of the liquid crystal display panel PNL, for example, a backlight BL is disposed via an optical sheet OS made of a diffusion sheet, a prism sheet, or a laminate thereof. The optical sheet OS diffuses or condenses light from the backlight BL and guides it to the liquid crystal display panel PNL side.

  The backlight BL is a so-called direct type, and a plurality of external electrodes, for example, external electrodes arranged in a plane parallel to the liquid crystal display panel PNL in the longitudinal direction in the x direction in the figure and arranged in parallel in the y direction in the figure. A lower frame (indicated by reference sign BS in FIGS. 3 and 4) that includes a base that supports the fluorescent tube EFL is provided. The lower frame BS is made of, for example, a box-shaped metal. A reflection sheet RS is arranged on the surface of the lower frame BS, and the reflection sheet RS is bent on each side in the x direction in the figure and has an obtuse angle with respect to the lower frame BS. It has a wall surface BW. Further, the lower frame BS includes a side wall plate BWh that is formed of, for example, a resin material at each side in the y direction in the drawing and has a light reflecting function on the surface on the liquid crystal display panel PNL side. The lower frame BS is inclined and has an obtuse angle. The side wall plate BWh constitutes a substantial side wall portion of the backlight BL together with the side wall surface BW of the reflection sheet RS. The configuration of the backlight BL will be described in detail later.

  Further, the liquid crystal display panel PNL, the optical sheet OS, and the backlight BL are modularized by a frame FR and an intermediate frame MR. FIG. 3 shows a cross-sectional view of the liquid crystal display device thus modularized, and corresponds to a cross section taken along line III-III in FIG. The upper frame FR has an opening OP that exposes the liquid crystal display area AR of the liquid crystal display panel PNL on the viewer side, and accurately positions the liquid crystal display panel PNL, the optical sheet OS, and the backlight BL together with the intermediate frame MR. Let me fix it. In the present embodiment, the semiconductor device SCD is formed on the substrate SUB1, but a so-called tape carrier type semiconductor device disposed between the printed circuit board (not shown) may be used. The semiconductor device can be bent and arranged in the vertical direction of FIG. 3, and the frame can be further narrowed.

  4A is a plan view showing only the backlight BL, and FIG. 4B is a cross-sectional view taken along the line bb of FIG. 4A.

  The side wall plate BWh is attached to the lower frame BS via an electrode support base TMT formed of, for example, a resin material. The side wall plate BWh is formed with a plurality of holes (notches) HL arranged in parallel on the side of the lower frame BS, and each of the external electrode fluorescent tubes EFL disposed through the holes HL. The electrode TM formed at the end is positioned on the back side of the side wall plate BWh.

  Each electrode TM of the external electrode fluorescent tube EFL is sandwiched (engaged) by an electrode fitting TMF disposed on the electrode support base TMT. Thus, each external electrode fluorescent tube EFL is supported on the lower frame BS side by the electrode fitting TMF, and power is supplied through the electrode fitting TMF.

  As shown in FIG. 1, the electrode fitting TMF is configured to be integrated with the same metal electrode support materials TMS1 and TMS2 disposed on both ends of each external electrode fluorescent tube EFL. FIG. 1 is a plan view showing the electrode support materials TMS1 and TMS2, and these electrode support materials TMS1 and TMS2 are respectively disposed on the electrode support bases TMT (indicated by TMT1 and TMT2 in the figure). .

  In FIG. 1, one electrode support material TMS1 is disposed on the left side of the region where the external electrode fluorescent tube EFL (shown by a dotted line) is disposed, and the other electrode support material TMS2 is disposed on the right side of the region. Each has a shape extending in the direction (y direction in the figure) intersecting the longitudinal direction of each external electrode fluorescent tube EFL. As a result, the electrode support TMS1 commonly supports the electrode TM at the left end of each external electrode fluorescent tube EFL in the drawing, and the electrode support TMS2 is provided for the electrode TM at the right end of each external electrode fluorescent tube EFL in the drawing. It is comprised so that a part may be supported in common.

  Further, in the electrode support TMS1, for example, three electrode fittings TMF arranged along the longitudinal direction of the electrode TM on the left side of each external electrode fluorescent tube EFL in the drawing sandwich the electrode TM, thereby The electrode fluorescent tube EFL is configured to support the left end. Similarly, in the electrode support TMS2, for example, three electrode metals TMF arranged along the longitudinal direction of the electrode TM on the right side of each external electrode fluorescent tube EFL in FIG. The external electrode fluorescent tube EFL is configured to support the right end. This is to ensure electrical contact with the other remaining electrodes TMF when electrical contact with at least one electrode fitting TMF is insufficient.

  As a result, the electrode support materials TMS1 and TMS2 are each composed of a plurality of electrode fittings TMF arranged in parallel in a direction intersecting with the connection portions JC between the pair of connection portions JC extending opposite to each other. The bracket group is configured to be supported in parallel in the extending direction of the connecting portion JC.

  And these electrode support materials TMS1 and TMS2 are shape | molded by the press work of a board | plate material, for example.

  Here, the electrode support material TMS1 configured in this manner has a structure fixed to the electrode support base TMT1 using an adhesive such as a screw and a double-sided tape. That is, the electrode support TMS1 is fixed to the electrode support TMT1 by a screw SC1 at one end on the upper side of the connection portion JC (left connection portion JC (L)) on the left side in the drawing, and the left connection portion JC. (L) is fixed to the electrode support base TMT1 by a double-sided tape GL disposed along the longitudinal direction of the left side connection portion JC (L) in the central portion excluding, for example, both ends, and further of the electrode support material TMS1 In the right side connection portion JC (right side connection portion JC (R)) in the figure, the electrode support base TMT1 is fixed by a double-sided tape GL disposed along the longitudinal direction of the right side connection portion JC (R).

  Similarly, the electrode support member TMS2 is also fixed to the electrode support base TMT2 using an adhesive such as a screw and a double-sided tape. That is, the electrode support TMS2 is fixed to the electrode support TMT2 by a screw SC2 at one lower end of the right connection portion JC (right connection portion JC (R)) in the drawing, and the right connection portion. For example, in the central portion excluding both ends of JC (R), it is fixed to the electrode support base TMT2 by the double-sided tape GL disposed along the longitudinal direction of the right connection portion JC (R). Of these, the left connection portion JC (left connection portion JC (L)) in the drawing is fixed to the electrode support TMT2 by a double-sided tape GL disposed along the longitudinal direction of the left connection portion JC (L).

  As described above, in fixing the electrode support bases TMT1 and TMT2 of the electrode support materials TMS1 and TMS2, at least the adhesive such as the double-sided tape GL can be used to make the fixing reliable.

  From this, even if it is necessary to use screws to fix the electrode support bases TMT1 and TMT2 of the electrode support materials TMS1 and TMS2, as shown in FIG. 1, one end of each of the electrode support materials TMS1 and TMS2 It is not necessary to use a screw at the location where the adhesive is used.

  Therefore, even when the electrode support materials TMT1 and TMT2 are stretched due to thermal expansion, the adhesive can follow the stretch to some extent, and the electrode support materials TMS1 and TMS2 float from the electrode support bases TMT1 and TMT2. It is possible to secure adhesion without causing any damage.

  Therefore, as another countermeasure when the adhesive is not used, for example, the electrode support materials TMS1 and TMS2 are compared with a case where a member for pressing the electrode support materials TMS1 and TMS2 against the electrode support bases TMT1 and TMT2 is provided. In addition, it is possible to avoid a squeak noise generated between the member and the member due to expansion due to thermal expansion.

  Further, as another countermeasure when the adhesive is not used, for example, compared with the case where the electrode support materials TMS1 and TMS2 are only screwed at both ends, the cause from the outside of the electrode support materials TMS1 and TMS2 It can be set as the structure which can avoid the chatter sound which generate | occur | produces between the said members by the vibration by such as.

  FIG. 5A is a detailed view of the electrode support TMS described above, in which a portion indicated by a dotted line frame A in FIG. 1 is extracted and drawn.

  In FIG. 5A, the electrode support member TMS1 includes a substrate BP that commonly fixes three electrode fittings TMF arranged in parallel and a left connection portion JC (L that is commonly connected at each end side of the base portion BP. ) And the right connection part JC (R), and these base part BP and each connection part JC (L), JC (R) are formed in a ladder-like pattern when viewed in plan. .

  FIG. 5B shows the electrode fitting TMF, and shows a cross-sectional view taken along the line bb of FIG. 5A. The electrode fitting TMF is configured as a bifurcated structure including a pair of opposing tongue pieces for sandwiching the external electrode fluorescent tube EFL from both sides. That is, the base portion BP of the electrode support member TMS1 is provided with a pair of support portions SP bent from both sides, for example, in the vertical direction, and each of the support portions SP attaches the external electrode fluorescent tube EFL to the peripheral side surface thereof. Arc portions that are pressed from opposite sides are provided. Further, the electrode fitting TMF is provided with an introduction part IT that spreads radially at each tip of each support part SP, and this introduction part IT is intended to facilitate the introduction of the external electrode fluorescent tube EFL to the support part SP. . In addition, the dotted line circle shown in FIG.5 (b) has shown the surrounding side surface of the external electrode fluorescent tube TMF.

  FIG. 6A shows a perspective view of the electrode support TMT1 to which the above-described electrode support TMS1 is fixed, and FIG. 6B shows a side wall that is fixed (temporarily fixed) by covering the electrode support TMT1. A perspective view of the plate BWh is shown.

  The side wall plate BWh shows a state viewed from the back side with respect to the surface on the liquid crystal display panel PNL side, and ribs RB extending in the short direction intermittently in the longitudinal direction are integrally formed. The rib RB is provided to improve the mechanical strength against deformation of the side wall plate BWh made of a resin material.

  The side wall plate BWh configured in this manner is placed on the electrode support base TMT1 shown in FIG. 6A by reversing the front and back from the state shown in the drawing, and further reversing the left and right. It can be made to.

  The electrode support base TMT1 is formed with screw holes SCH arranged in parallel in the longitudinal direction thereof, and the side wall plate WBh is also formed with screw holes SCH ′ corresponding to the screw holes SCH, with respect to the electrode support base TMT1. When the side wall plates BWh are temporarily fixed, their central axes are matched. The electrode support base TMT1 and the side wall plate BWh temporarily fixed in this way are fixed to the lower frame BS by screws (not shown) screwed into the lower frame BS through their screw holes SCH and SCH ′. It has become so.

  FIG. 7 shows a view in which the electrode support base TMT1 and the side wall plate BWh are fixed to the lower frame BS as viewed from the axial direction of the external electrode fluorescent tube EFL.

  In FIG. 7, the electrode supporting member TMS1 including the electrode fitting TMF has its connecting portion JC (the right connecting portion JC (R) is observed in the figure) fixed to the electrode supporting base TMT1 via the double-sided tape GL. It is shown that.

  Each rib RB formed integrally with the side wall plate WBh is provided, for example, between each adjacent electrode metal TMF, and the right side connection portion JC (R) of the electrode support member TMS1 and the left side connection (not shown). It is positioned with a sufficient distance W from the part JC (L). As described above, each rib RB of the side wall plate WBh is provided in order to improve the mechanical strength of the side wall plate BWh, and the function of preventing squeak or chatter noise caused by the electrode support material TMS1 by the ribs RB. It is not a configuration with As described above, the electrode support material TMS1 is fixed to the electrode support base TMT1 via the double-sided tape GL at the connection portion JC, thereby sufficiently reducing the occurrence of squeak noise or chatter noise. Because.

  In addition, according to the present invention, it is possible to reduce beat noise. As the cause of the roaring sound, periodic energy is applied to the external electrode fluorescent tube EFL of the backlight, the electrode support base TMT, the electrode support material TMS, and the like, and the sound is generated. This periodic energy is generated when PWM dimming is performed on the backlight system. The PWM dimming is a lamp dimming control by ON / OFF control of the lamp at a frequency up to several hundred Hz. That is, in a system that performs PWM dimming control, it is considered that displacement due to the piezoelectric effect on the electrode support material TMS occurs, and this may cause a roaring sound. Therefore, by fixing the electrode support material TMS to the electrode support base TMT as in the present invention, even if periodic energy is applied to these, the noise is reduced, and as a result, the beat sound is reduced. It is possible to do that.

  FIG. 8 is a view showing another embodiment of the liquid crystal display device according to the present invention and corresponds to FIG.

  1 is different from the case of FIG. 1 in that the electrode support TMS1 is fixed to the electrode support TMT1 by the double-sided tape GL at, for example, the right connection JC (R) of the electrode support TMS1. L) is not done. The electrode support TMS2 is fixed to the electrode support TMS2 by the double-sided tape GL, for example, at the left connection JC (L) of the electrode support TMS2 and not at the right connection JC (R).

  According to the present embodiment, the electrode support materials TMS1 and TMS2 may be fixed to the electrode support bases TMT1 and TMT2 by an adhesive at a required place, and does not necessarily need to cover the entire area. The configuration shown in FIG. 8 can be applied when the liquid crystal display panel PNL is about 26 inches in size and the backlight BL is not so large.

  FIG. 9 is a view showing another embodiment of the liquid crystal display device according to the present invention and corresponds to FIG.

  1 differs from the case of FIG. 1 in that, for example, the left side connection portion JC (L) of the electrode support member TMS1 is fixed at both ends using screws SC1, SC′1, respectively, and the electrode support member TMS2 is connected to the right side, for example. At both ends of the portion JC (R), they are fixed using screws SC2, SC′2, respectively.

  In such a configuration, for example, the size of the backlight BL is not so large (the size of the liquid crystal display panel PNL is about 26 inches), and even if the electrode support materials TMS1 and TMS2 are expanded by heat, double-sided tape It can be applied to the case where the GL is adhered to the electrode support bases TMT1 and TMT2 without being peeled off.

  In the above-described embodiment, the electrode support TMS is fixed to the electrode support TMT with an adhesive made of the double-sided tape GL. However, it is not limited to a double-sided tape, and other adhesives may be used. This is because the same effect is achieved.

  Each of the embodiments described above may be used alone or in combination. This is because the effects of the respective embodiments can be achieved independently or synergistically.

It is a principal part block diagram which shows one Example of the liquid crystal display device by this invention. It is a schematic block diagram which shows one Example of the liquid crystal display device by this invention. It is a figure of the liquid crystal display device modularized, and is sectional drawing of the location corresponded to the III-III line | wire of FIG. It is a block diagram which shows one Example of the backlight of the liquid crystal display device by this invention. It is a block diagram which shows one Example of the electrode support material used for the liquid crystal display device by this invention. It is a perspective view which shows one Example of the electrode support stand used for the liquid crystal display device by this invention, and the side wall board fixed to it (temporarily fixed). It is explanatory drawing which shows the positional relationship of the rib of a side wall board, and an electrode support material. It is a principal part block diagram which shows the other Example of the liquid crystal display device by this invention. It is a principal part block diagram which shows the other Example of the liquid crystal display device by this invention.

Explanation of symbols

  PNL: Liquid crystal display panel, OS: Optical sheet, BL: Backlight, BS: Lower frame, RS: Reflective sheet, BW ... Side wall surface, BWh ... Side wall plate, EFL: External electrode fluorescent tube , FR: Upper frame, MR: Intermediate frame, TMS: Electrode support material, TMF ... Electrode fitting, JC: Connection part, BP ... Base part, SP ... Support part, IN ... Introduction part, GL ... Double-sided tape, TMT ... Electrode support base, SCH ... Screw hole, RB ... Rib, SC ... Screw.

Claims (8)

A liquid crystal display panel and a backlight disposed on the back of the liquid crystal display panel;
The backlight is composed of a plurality of rod-shaped light sources arranged in parallel in a plane facing the liquid crystal display panel, and a base that supports each of the rod-shaped light sources via electrode fittings at the electrode portions thereof,
The electrode fittings are configured to support the corresponding electrode portions of each rod-shaped light source, connected to a connection portion extending in the juxtaposition direction of the rod-shaped light sources,
The liquid crystal display device, wherein the connecting portion is fixed to the base side through at least an adhesive.   The liquid crystal display device according to claim 1, wherein the adhesive is made of a double-sided tape extending along a longitudinal direction of the connection portion.   The liquid crystal display device according to claim 1, wherein the connection portion is fixed to the base side via a screw at one end side thereof.   The liquid crystal display device according to claim 1, wherein the connection portion is fixed to the base side via screws at both ends thereof.   The connecting portion is composed of a pair of connecting portions that connect the electrode fittings at both ends thereof, and the adhesive for fixing to the base side is provided in each of the connecting portions. The liquid crystal display device according to claim 1.   The connecting portion is composed of a pair of connecting portions that connect the electrode fittings at both ends thereof, and the adhesive for fixing to the base side is attached to one connecting portion of the connecting portions. The liquid crystal display device according to claim 1, wherein the liquid crystal display device is interposed.   7. The liquid crystal display device according to claim 5, wherein one of the connection portions is fixed to the base side via a screw at one end side of the connection portion.   7. The liquid crystal display device according to claim 5, wherein the liquid crystal display device is fixed to the base side via a screw at both ends of one of the connection portions.

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