JP2010078625A - Liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display device having conductive rubber disposed in a cell case without causing misalignment between an electrode of the conductive rubber and electrodes provided on a liquid crystal display panel and a circuit board. <P>SOLUTION: The liquid crystal display device includes: a liquid crystal display panel 1 having an electrode terminal 13 formed at one end thereof; a cell case 3 including a side wall holding the liquid crystal display panel 1 and an outer wall 33 provided at the outside of a side wall 31A corresponding to the electrode terminal 13, along and in parallel with the side wall 31A; a circuit board 5 disposed at the rear of the cell case 3 and having a circuit terminal 51 formed correspondingly to the electrode terminal 13; and conductive rubber 6 disposed in a space S1 between the side wall 31A and the outer wall 33 and electrically connecting the electrode terminal 13 to the circuit terminal 51. A wall portion 332 protrudes along a lengthwise direction of the outer wall 33 on an outer surface 331 of the outer wall 33. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a liquid crystal display device including a liquid crystal display panel and a conductive rubber as a current-carrying member for the liquid crystal display panel.

  As a liquid crystal display device including a liquid crystal display panel, a circuit board on which a circuit for driving the liquid crystal display panel and the like are mounted, and a conductive rubber as a current-carrying member that electrically connects the liquid crystal display panel and the circuit board, for example, There exists patent document 1. FIG. Patent Document 1 discloses a liquid crystal display element 1 (corresponding to the liquid crystal display panel of the present application), a synthetic resin holder 5 (corresponding to a cell case) that holds the liquid crystal display element 1, and a back of the holder 5. As a current-carrying member for electrically connecting the liquid crystal display element 1 and the circuit board 4 to a hard circuit board 4 on which a light source 3 for illuminating the liquid crystal display element 1 and a circuit for driving the liquid crystal display element 1 are mounted. A liquid crystal display device provided with a conductive rubber 7 is described.

The conductive rubber 7 is inserted into an insertion hole 57 formed in a part of the peripheral wall portion 51 of the holder 5 having a frame shape. The size of the insertion hole 57 is substantially equal to the thickness of the conductive rubber 7, and the insertion hole 57 is formed by providing a side wall portion (not indicated) parallel to the peripheral wall portion 51 outside the peripheral wall portion 51 ( (Refer FIG. 2 of patent document 1).
JP 2008-89660 A

  However, in the liquid crystal display device of Patent Document 1, there is a possibility that the side wall portion of the holder 5 formed by injection molding is deformed. As shown in FIG. 2, the peripheral wall 51 is thick and rigid because the step receiving portion 52 and the bottom are integrally provided, and is difficult to be deformed. There is a possibility that the central part may be deformed by molding shrinkage. When the vicinity of the center of the side wall portion warps (deforms) toward the peripheral wall portion 51, the conductive rubber 7 does not enter the insertion hole 57 or is difficult to enter. Therefore, it is conceivable that the size of the insertion hole 57 allows for warping. In this case, since the conductive rubber 7 enters the insertion hole 57, but both sides of the insertion hole 57 are wide (become the thickness of the conductive rubber 7), the conductive rubber is inserted in the insertion hole 57 in the process of assembling the liquid crystal display device. 7 may move, and positional displacement may occur between the electrode of the conductive rubber 7 and the electrode provided on the liquid crystal display element 1 or the circuit board 4. Further, when the vicinity of the center of the side wall portion is warped outward, the center portion of the insertion hole 57 is widened, and the electrode of the conductive rubber 7 and the electrode provided on the liquid crystal display element 1 or the circuit board 4 are the same as described above. There is a possibility that misalignment occurs. As a result, an energization failure may occur and the display of the liquid crystal display element 1 may be hindered.

  The present invention has been made in view of such a point, and the conductive rubber is disposed in the cell case without causing displacement of the electrodes of the conductive rubber and the electrodes provided on the liquid crystal display panel and the circuit board. An object of the present invention is to provide a liquid crystal display device capable of performing

  In order to achieve the above object, the present invention provides a liquid crystal display panel having an electrode terminal formed at one end thereof, a side wall on which the liquid crystal display panel is held, and a side wall portion corresponding to the electrode terminal and provided parallel to the outside. A cell case having an outer wall formed thereon, a circuit board disposed behind the cell case and having circuit terminals formed corresponding to the electrode terminals, and disposed in a space between the side wall and the outer wall. A conductive rubber for electrically connecting the electrode terminal and the circuit terminal is provided, and a wall portion along the longitudinal direction of the outer wall is projected from the outer surface side of the outer wall.

  The liquid crystal display device further includes a pressing frame for fixing the cell case to the circuit board. The pressing frame covers a peripheral upper surface of the liquid crystal display panel, and the outer wall extends from the covering unit. A side portion extending along the circuit board side and a leg portion provided on the side portion and having a locking portion on the lower end side, and the locking portion at the wall portion corresponding to the locking portion. Is provided so as to extend along the outer surface of the outer wall, and a hole portion through which the locking portion is inserted is provided at the circuit board portion.

  Further, the wall portion is provided at an end portion of the outer wall on the circuit board side so as to be in contact with the circuit board.

  It is possible to obtain a liquid crystal display device in which the conductive rubber can be disposed in the cell case without causing positional displacement between the electrode of the conductive rubber and the electrodes provided on the liquid crystal display panel and the circuit board.

  FIG. 1 is an exploded perspective view of a liquid crystal display device showing an embodiment of the present invention. 2 is a cross-sectional view of the liquid crystal display device showing the AA direction in FIG. 1, and FIG. 3 is a cross-sectional view of the liquid crystal display device showing the BB direction in FIG.

  The liquid crystal display device includes a transmissive liquid crystal display panel 1, a sheet-like diffusion plate 2 disposed behind the liquid crystal display panel 1, a cell case 3 in which the liquid crystal display panel 1 and the diffusion plate 2 are held, A rigid circuit board mounted behind the cell case 3 and mounted with a light emitting diode 4 as a light source for illuminating the liquid crystal display panel 1 and the diffusion plate 2 from the back, a circuit (not shown) for driving the liquid crystal display panel 1, and the like 5, for example, a conductive rubber 6 as an energizing member that electrically connects an electrode portion (not shown) formed on the liquid crystal display panel 1 and a circuit of the circuit board 5, and the liquid crystal display panel 1 and the cell case 3. A metal pressing frame 7 for fixing to the circuit board 5 is provided.

  Although not shown in detail, the liquid crystal display panel 1 includes liquid crystal molecules sealed between a front glass substrate 11 and a rear glass substrate 12, and a polarizing film is pasted on each glass substrate 11 and 12, as is well known. is there. When a signal (voltage) corresponding to the external measurement amount is applied to the electrode portions of the glass substrates 11 and 12 via the conductive rubber 6, the vehicle operating state (for example, the vehicle speed and travel distance, or the fuel remaining) The liquid crystal display portion on which the amount is displayed appears in black. The background portion other than the liquid crystal display portion is transmitted and illuminated by lighting of the light emitting diode 4.

  Although not shown in detail, the conductive rubber 6 has a laminated structure in which conductive layers and insulating layers are alternately laminated along the longitudinal direction, and is formed by being drawn around the back side of the front glass substrate 11 of the liquid crystal display element 1. The circuit board 5 and the liquid crystal display element 1 are electrically connected by interposing between the electrode terminal 13 formed and the circuit terminal 51 formed around the circuit board 5 and closely contacting the electrode terminal 13 and the circuit terminal 51. It is the electricity supply member which has the elasticity which aims at.

  The diffusion plate 2 uniformly guides the light from the light emitting diode 4 to the back side of the liquid crystal display panel 1, and the outer shape is substantially the same as that of the liquid crystal display panel 1. Although not shown, the diffusion plate 2 has a white transmissive layer printed on the surface (surface on the liquid crystal display panel 1 side) of a sheet material made of, for example, a polycarbonate resin that is a colorless and transparent synthetic resin. In addition, light control printing (halftone printing or the like) is performed on the back surface (light emitting diode 4 side) so that the light irradiated on the diffusion plate 2 is almost uniform and emitted to the liquid crystal display panel 1 side. Further, positioning pieces 21 for positioning with the cell case 3 are projected from both edges in the longitudinal direction. Note that the diffusion plate 2 may be a synthetic resin sheet material having transparency, for example, milky white.

  The cell case 3 is made of, for example, white synthetic resin, and the side wall 31 on which the diffusion plate 2 and the liquid crystal display panel 1 are held, and the periphery of the diffusion plate 2 and the liquid crystal display panel 1 formed on the side wall 31 are placed. Diffusion plate mounting surface 311 and panel mounting surface 312, a bottom wall 32 having an opening 321 provided corresponding to the light emitting diode 4, and a side wall corresponding to the electrode terminal 13 formed in the liquid crystal display panel 1. It has the outer wall 33 provided in parallel with the outer side of the side wall 31A along 31A location. By providing the outer wall 33, the conductive rubber 6 is inserted (arranged) in a space S1 formed between the side wall 31A. The size of the void S1 is approximately equal to the thickness of the conductive rubber 6.

  Further, a wall portion 332 along the longitudinal direction of the outer wall 33 is provided on the outer surface 331 side of the outer wall 33. The wall portion 332 protrudes from the end of the outer wall 33 on the circuit board 5 side in a direction substantially orthogonal to the outer wall 33 and is in contact with the circuit board 5. A plurality of through holes 333 are provided at the corners of the outer wall 33 and the wall portion 332 along the outer surface 331 of the outer wall 33.

  Further, holding pieces 34 for locking the upper surface of the edge of the diffusion plate 2 are provided at 31 locations on the side wall 31 of the cell case 3 corresponding to the four corners of the diffusion plate 2.

  In addition, positioning pins 322 are formed at appropriate positions on the bottom wall 32. The positioning pin 322 is inserted into a positioning hole 52 provided in the circuit board 5 to position the cell case 3 and the circuit board 5.

  The presser frame 7 is formed by pressing a metal plate. A frame-shaped cover 71 that continuously covers the peripheral upper surface of the liquid crystal display panel 1 and the side wall 31 and the outer wall 33 of the cell case 3 from the cover 71. A frame-like side portion 72 extending toward the circuit board 5 along the plurality of leg portions 73 provided at appropriate locations on the side portion 72 and having a locking portion 731 on the lower end side. The leg portions 73 are provided corresponding to the through holes 333 provided in the cell case 3, and are also provided at 72 locations on the side portion corresponding to the side wall 31 located on the side opposite to the side wall 31A on the outer wall 33 side. is there.

  The leg 73 provided corresponding to the through hole 333 is inserted into the through hole 333 and also inserted into the hole 53 provided at five locations on the circuit board corresponding to the through hole 333. It has become. Further, the leg portion 73 provided on the side portion 72 corresponding to the side wall 31 is inserted into the hole portion 53 provided at five locations on the circuit board corresponding to the leg portion 73. A synthetic rubber sheet 8 is disposed between the cover 71 and the peripheral upper surface of the liquid crystal display panel 1. The synthetic rubber sheet 8 is for buffering the cover 71 and the liquid crystal display panel 1 and is pasted on the cover 71 of the holding frame 7 in advance.

  The liquid crystal display device is assembled as follows. First, the positioning pin 322 of the cell case 3 is inserted into the positioning hole 52 of the circuit board 5, and the cell case 3 is arranged on the circuit board 5. Next, the diffusion plate 2 is inserted between the holding piece 34 and the diffusion plate mounting surface 311 while bending the diffusion plate 2. Accordingly, the upper surface of the edge of the diffusion plate 2 is locked by the holding piece 34 and is held by the cell case 3. Then, the conductive rubber 6 is disposed in the space S <b> 1 formed in the cell case 3.

  Next, the liquid crystal display panel 1 is placed on the panel placement surface 312 of the cell case 3, and the pressing frame 7 is attached from above the liquid crystal display panel 1. At that time, the locking portion 731 and the leg portion 73 provided on the holding frame 7 are moved along the outer wall 33 and the side wall 31 of the cell case 3, and the leg portion 73 having the locking portion 731 is moved to the outer surface 331 of the outer wall 33. Are inserted through the through holes 333 provided along the circuit board 5 and through the holes 53 provided in the circuit board 5. The leg 73 moved while being moved along the side wall 31 is directly inserted into the hole 53 of the circuit board 5. Then, each locking portion 731 is bent on the back side of the circuit board 5.

  By doing so, the liquid crystal display panel 1 is held by the cell case 3 and is assembled to the circuit board 5. The liquid crystal display panel 1 may be press-fitted and fixed on the side wall 31 of the cell case 3 or a so-called hook stop by providing an elastic locking piece on the side wall 31. In addition, the diffusion plate 2 may be held in the cell case 3 in advance, and when the diffusion plate 2 is held on the diffusion plate mounting surface 311, the method is not limited to the method of holding the upper surface of the edge of the diffusion plate 2 with the holding piece 34. However, press fitting, hooking, etc. are optional.

  In this manner, the liquid crystal display panel 1 having the electrode terminal 13 formed at one end, the side wall 31 on which the liquid crystal display panel 1 is held, and the side wall 31A corresponding to the electrode terminal 13 are parallel to the outside of the side wall 31A. Between the cell case 3 having the outer wall 33 provided, the circuit board 5 disposed behind the cell case 3 and having the circuit terminals 51 corresponding to the electrode terminals 13, and between the side wall 31 </ b> A and the outer wall 33. The conductive rubber 6 is disposed in the space S1 and electrically connects the electrode terminal 13 and the circuit terminal 51, and the wall portion 332 along the longitudinal direction of the outer wall 33 protrudes on the outer surface 331 side of the outer wall 33. Thus, the outer wall 33 having rigidity is obtained, and deformation of the outer wall 33 is suppressed.

  Therefore, the conductive rubber 6 can be inserted even if the space S1 in which the conductive rubber 6 is disposed has a size approximately equal to the thickness of the conductive rubber 6. Further, since it is not necessary to increase the space S1, the electrode of the conductive rubber 6 and the electrode terminal 13 formed on the liquid crystal display panel 1 and the circuit terminal 51 formed on the circuit board 5 are not displaced. A liquid crystal display device having a good display state can be obtained.

  The liquid crystal display device also includes a pressing frame 7 for fixing the cell case 3 to the circuit board 5. The pressing frame 7 includes a cover 71 that covers the upper surface of the periphery of the liquid crystal display panel 1, and the cover 71. A wall portion 332 having a side portion 72 extending toward the circuit board 5 along the outer wall 33 and a leg portion 73 provided on the side portion 72 and having a locking portion 731 on the lower end side, corresponding to the locking portion 731. By providing a through hole 333 through which the locking portion 731 is inserted along the outer surface 331 of the outer wall 33 and providing a hole 53 through which the locking portion 731 is inserted at five locations on the circuit board, the locking portion 731 can be inserted through the through hole 333 along the outer wall 33. That is, the retaining frame 7 may be inserted into the through-hole 333 while the retaining frame 7 is moved in a state where the engaging portion 731 is in contact with the outer surface 331 of the outer wall 33, so that the engaging portion 731 and the leg portion 73 are inserted into the through-hole 333. Good workability when inserting into the cable.

  Further, since the wall portion 332 is provided at the end of the outer wall 33 on the circuit board 5 side so as to be in contact with the circuit board 5, the locking portion 731 and the leg portion 73 inserted through the through hole 333 of the cell case 3 are connected to the circuit board 5. It becomes easy to enter the hole 53 of the substrate 5.

  In the present embodiment, the metal pressing frame 7 is used to fix the liquid crystal display panel 1 and the cell case 3 to the circuit board 5, but a synthetic resin pressing frame may be used. In that case, the holding frame may be screwed to the circuit board 5 or the holding frame may be hooked to the circuit board 5 using an elastic locking piece.

  In addition, the liquid crystal display device of the present invention can be applied even when the liquid crystal display device is incorporated in a vehicle meter device equipped with a speedometer, a tachometer, etc. In this case, the cell case is a meter constituting the meter device. It may be integral with the case.

The disassembled perspective view of the liquid crystal display device which shows embodiment of this invention. Sectional drawing of the liquid crystal display device which shows the AA direction in FIG. Sectional drawing of the liquid crystal display device which shows the BB direction in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Liquid crystal display panel 13 Electrode terminal 2 Diffusion board 3 Cell case 31, 31A Side wall 33 Outer wall 331 Outer surface 332 Wall part 333 Through-hole S1 Space 5 Circuit board 51 Circuit terminal 53 Hole part 6 Conductive rubber 7 Holding frame 71 Cover part 72 side Part 73 leg part 731 locking part

Claims (3)

  A cell case having a liquid crystal display panel having an electrode terminal formed at one end thereof, a side wall on which the liquid crystal display panel is held, and an outer wall provided parallel to the outside along the side wall portion corresponding to the electrode terminal; A circuit board disposed behind the cell case and having a circuit terminal formed corresponding to the electrode terminal, and the electrode terminal and the circuit terminal disposed in a space between the side wall and the outer wall are electrically connected. And a conductive rubber connected to the outer wall, wherein a wall portion along the longitudinal direction of the outer wall projects from the outer surface of the outer wall.   The liquid crystal display device includes a pressing frame for fixing the cell case to the circuit board, and the pressing frame covers a peripheral upper surface of the liquid crystal display panel, and extends from the covering section along the outer wall. A side portion extending to the circuit board side and a leg portion provided on the side portion and having a locking portion on the lower end side, and the locking portion is inserted into the wall portion corresponding to the locking portion. The liquid crystal display device according to claim 1, wherein a through-hole to be formed is provided along the outer surface of the outer wall, and a hole portion through which the locking portion is inserted is provided at the circuit board portion.   The liquid crystal display device according to claim 2, wherein the wall portion is provided at an end portion of the outer wall on the circuit board side so as to be in contact with the circuit board.

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