JP5273553B2 - Liquid crystal display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display device that connects a liquid crystal display to a circuit board through a flexible printed wiring board, and can be thinned, while suppressing deflection of the flexible printed wiring board. <P>SOLUTION: In the liquid crystal display device includes the liquid crystal display 2, having a liquid crystal display panel 1, a hard circuit board 4, that is arranged behind the liquid crystal display 2 and has a connector 3 mounted on its rear side, and the flexible printed wiring board 5 for connecting the liquid crystal display panel 1 to the connector 3, the flexible printed wiring board 5 includes a display panel connection section 17, connected to one end of the liquid crystal display panel 1; a connector connection section 25 connected to the connector 3; and a fixing section 26 fixed to the rear side of the liquid crystal display 2. The circuit board 4 has a notch 28 for pulling the flexible printed wiring board 5, disposed from the fixing section 26 to the connector connection section 25 up to the connector 3. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a liquid crystal display device provided in, for example, a vehicle meter, and more particularly to a liquid crystal display device in which a liquid crystal display panel and a hard circuit board are connected by a flexible printed wiring board.

  As such a liquid crystal display device, for example, there is Patent Document 1 below. In the liquid crystal display device described in Patent Document 1, when the liquid crystal display body 3 and the circuit board 1 are electrically connected using a flexible tape 4 (flexible printed wiring board), the conventional technique is shown in FIG. As shown, the flexible tape 4 is drawn around the end face of the liquid crystal display body 3 and the end face of the circuit board 1. However, when an impact or load is applied to the flexible tape 4 from the end face side, the flexible tape 4 has an acute angle. The conductive pattern is disconnected by being pressed against the end face and the end face of the circuit board 1, and there is a problem that electrical connection between the liquid crystal display 3 and the circuit board 1 cannot be taken. Therefore, as shown in FIG. 1 of Patent Document 1, since an opening 5 is provided in the circuit board 1 and the flexible tape 4 is passed through the opening 5 so that no load is applied directly to the flexible tape 4, It is possible to prevent a problem that the liquid crystal display body 3 end face and the circuit board 1 end face are pressed and disconnected.

Japanese Patent Laid-Open No. 11-212483

  However, even when the structure shown in FIG. 1 of Patent Document 1 is applied, when the liquid crystal display device is vibrated, the flexible tape 4 is shaken, and particularly the end face of the opening 5 of the circuit board 1 is rubbed to break the conductive pattern. There is a fear. The conventional (FIG. 2) is the same, but since the flexible tape 4 is drawn around the end face of the liquid crystal display 3 and the end face of the circuit board 1 (end face of the opening 5), it bends to the bent portion of the flexible tape 4. Occurs. And when this bending is large, a liquid crystal display device will become thick and there exists a problem that it is not suitable for thickness reduction.

  The present invention has been made in view of the above points, and in a liquid crystal display device in which a liquid crystal display and a circuit board are connected by a flexible printed wiring board, the thickness of the flexible printed wiring board is reduced while suppressing vibration. 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 provided with a liquid crystal display panel, a rigid circuit board disposed behind the liquid crystal display and having a connector mounted on the back side, the liquid crystal display panel, and the liquid crystal display panel. In a liquid crystal display device comprising a flexible printed wiring board for connecting to a connector, the flexible printed wiring board is connected to one end of the liquid crystal display panel and a connector connected to the connector. A notch for routing the flexible printed wiring board from the fixing part to the connector connecting part to the connector; and a connecting part and a fixing part fixed to the back side of the liquid crystal display. It has a part.

Further, the connector, the conjunction than the fixing portion which is fixed to the rear surface side of the liquid crystal display is mounted on 箇 office corresponding to the connector connecting portion closer, the inserted part of the connector assembly is inserted Is substantially parallel to the plate surface of the circuit board.

  The fixing part is an area where electronic parts for driving the liquid crystal display are mounted.

  In a liquid crystal display device in which a liquid crystal display and a circuit board are connected by a flexible printed wiring board, it is possible to obtain a liquid crystal display device that can be reduced in thickness while suppressing deflection of the flexible printed wiring board.

It is a back view of the liquid crystal display device which shows embodiment of this invention. It is a side view of the liquid crystal display device. It is a fragmentary sectional view which shows the principal part of the liquid crystal display device.

  The liquid crystal display device includes a liquid crystal display 2 having a liquid crystal display panel 1, a rigid circuit board 4 disposed behind the liquid crystal display 2 and having a connector 3 mounted on the back side, the liquid crystal display panel 2 and the connector. The flexible printed wiring board 5 which connects 3 is provided.

  The liquid crystal display 2 includes a rectangular transmissive liquid crystal display panel 1, a case 6 disposed behind the liquid crystal display panel 1, and a light emitting diode 8 disposed along the inside of the peripheral wall portion 7 of the case 6. And a light guide plate 10 having a light receiving portion 9 disposed between the liquid crystal display panel 1 and the case 6 and facing the light emitting diode 8, and an optical film such as a diffusion sheet or a prism sheet disposed on the front side of the light guide plate 10 11, the rear frame 12 which is disposed between the light guide plate 10 and the case 6 and holds the light guide plate 10 and the optical film 11, and holds the liquid crystal display panel 1 while holding the peripheral portions of the optical film 11 and the light guide plate 10. A front frame 13 and a panel holding member 14 for holding the peripheral portion of the liquid crystal display panel 1 are provided.

  The liquid crystal display panel 1 is a dot matrix type having pixels (dots) arranged in a matrix. Although details are omitted (not shown), after the front glass substrate 15 on which the transparent electrode made of ITO is formed and the rear glass substrate 16 are overlapped and the periphery is fixed with a sealant, each glass substrate 15, The liquid crystal molecules are sealed between the glass substrates 15 and 16 and, for example, smoked polarizing films are attached to the glass substrates 15 and 16.

  A display panel connection portion 17, which is one end portion of the flexible printed wiring board 5, is fixed to one end portion (one end of the square) on the front side of the rear glass substrate 16. When a signal (voltage) corresponding to the external measurement amount is applied to the transparent electrode through the flexible printed wiring board 5, various information such as the travel distance of the vehicle, the time of day, and the outside temperature is displayed in black on the liquid crystal display panel 1. The background is displayed and transmitted and illuminated by lighting of the light emitting diode 8.

  The case 6 is substantially the same shape as the liquid crystal display panel 1 and is made of, for example, aluminum which is a metal material. The case 6 includes a bottom wall portion 18 and a peripheral wall portion 7 erected around the bottom wall portion 18. A plurality of light emitting diodes 8 are arranged on the inner side of the peripheral wall portion 7 toward the light receiving portion 9 side of the light guide plate 10 through an FPC 19 in which a conductive circuit for lighting the light emitting diode 8 is formed.

  The light guide plate 10 is made of synthetic resin such as colorless and transparent acrylic or polycarbonate, and a light receiving portion 9 is provided on a side surface facing the light emitting diode 8. In addition, fine irregularities (textures) are formed on the back surface so that light from the light emitting diode 8 incident on the light guide plate 10 from the light receiving portion 9 is reflected by the irregularities and directed toward the front surface side of the light guide plate 10. It has become. The light guide plate 10 is accommodated in the rear frame 12.

  The rear frame 12 is made of, for example, white synthetic resin having a light shielding property, and has a bottom wall portion 18A and a mounting boss 20 that protrudes from the bottom wall portion 18A through the bottom wall portion 18 of the case 6 to the circuit board 4 side. Etc.

  The front frame 13 is made of, for example, a white synthetic resin having a light-shielding property, and has an edge portion 21 that presses the peripheral portions of the optical film 11 and the light guide plate 10, and an enclosure portion 22 that extends from the edge portion 21 toward the case 6. doing. The liquid crystal display panel 1 is disposed on the edge 21 of the front frame 13.

  After the light guide plate 10 and the optical film 11 are held, the frame 12 is accommodated in the case 6, and although not shown, the enclosure 22 of the front frame 13 is engaged with the peripheral wall portion 7 of the case 6. The peripheral portion is pressed by the edge portion 21 of the front frame 13, and the rear frame 12 holding the light guide plate 10 and the optical film 11 is assembled in the case 6.

  The panel retainer 14 is made of, for example, a stainless steel plate, which is a metal material, and has a panel edge 23 and a panel enclosure 24. After arranging the liquid crystal display panel 1 on the edge 21 of the front frame 13, although not shown, the peripheral edge of the liquid crystal display panel 1 is secured by engaging the panel enclosure 24 of the panel holder 14 with the enclosure 22 of the front frame 13. The portion is pressed by the panel edge 23 of the panel holder 14, and the liquid crystal display panel 1 is assembled to the front frame 13.

  Although not shown in detail, the flexible printed wiring board 5 is formed by etching, for example, a conductive portion (conductive circuit) made of copper foil connected to the electrode portion of the liquid crystal display panel 1 in a synthetic resin base film made of polyimide resin, for example. After forming by the method, a protective film for insulation protection is bonded. As described above, the display panel connection portion 17 connected to the liquid crystal display panel 1 is fixed to the surface side of the rear glass substrate 16. The other end side of the flexible printed wiring board 5 is a connector connecting portion 25 connected to the connector 3. Further, a fixing portion 26 is provided between the display panel connection portion 17 and the connector connection portion 25.

  The fixing portion 26 is a portion fixed to the back surface side of the liquid crystal display 2, in this embodiment, the back surface side of the case 6 (the back surface of the bottom wall portion 18). In the present embodiment, the fixing portion 26 is also a region where the electronic component 27 that drives the liquid crystal display 2 is mounted. Since the electronic component 27 is mounted on the fixed portion 26, the fixed portion 26 has rigidity compared to other regions (other than the fixed portion 26). The flexible printed wiring board 5 routed between the enclosure portion 22 of the front frame 13 and the panel enclosure portion 24 of the panel retainer 14 is fixed to the back side of the case 6 by using, for example, a double-sided adhesive tape. The In FIG. 1, the hatched area is the fixed portion 26 and is also an area where the electronic component 27 is mounted.

  The circuit board 4 is made of, for example, an epoxy resin-based material, and in addition to the connector 3, a drive circuit for driving the liquid crystal display 2 and a power supply circuit for lighting the light-emitting diode 8 are mounted. The circuit board 4 is provided with a notch 28. The cutout portion 28 is provided to route the flexible printed wiring board 25 from the fixed portion 26 of the flexible printed wiring board 5 to the connector connecting portion 25 to the connector 3 mounted on the back side of the circuit board 4. The flexible printed wiring board 5 is provided at a location substantially corresponding to the fixing portion 26.

  The circuit board 4 is fixed to a mounting boss 20 provided on the rear frame 12 and penetrating the bottom wall portion 18 of the case 6 with, for example, screws 29. Since the 28 notch portions provided on the circuit board 4 are only locations corresponding to the fixing portions 26 of the flexible printed wiring board 5, the liquid crystal display 2 can be stably attached to the circuit board 4.

  When the fixing portion 26 of the flexible printed wiring board 5 is fixed to the back surface side of the case 6, the connector 3 is mounted on four places on the circuit board corresponding to the connector connecting portion 25 closer to the fixing portion 26. Further, the inserted portion 30 into which the connector connecting portion 25 of the flexible printed wiring board 5 is inserted is mounted so as to be substantially parallel to the plate surface of the circuit board 4.

  In this way, the liquid crystal display 2 provided with the liquid crystal display panel 1, the rigid circuit board 4 disposed behind the liquid crystal display 2 and having the connector 3 mounted on the back side, the liquid crystal display panel 1 and the connector 3 In the liquid crystal display device including the flexible printed wiring board 5 for connecting the liquid crystal display panel 1, the flexible printed wiring board 5 is connected to the display panel connecting portion 17 connected to one end portion of the liquid crystal display panel 1 and the connector 3. The connector connecting portion 25 and a fixing portion 26 fixed to the back surface side of the liquid crystal display 2 are provided. The fixing portion 26 is connected to the back surface side of the liquid crystal display device 2 (in this embodiment, the back surface side of the case 6). ), The vibration of the flexible printed wiring board 5 can be suppressed even when vibration is applied to the liquid crystal display device.

  In addition, the circuit board 4 is wound up by providing the circuit board 4 with a notch 28 for routing the flexible printed wiring board 5 from the fixing part 26 of the flexible printed wiring board 5 to the connector connection part 25 to the connector 3. Thus, there is no need to route the flexible printed wiring board 5, the amount of bending of the flexible printed wiring board 5 is suppressed, and the liquid crystal display device can be thinned.

  The connector 3 is mounted on four places on the circuit board corresponding to the connector connection portion 25 rather than the fixing portion 26 when the fixing portion 26 of the flexible printed wiring board 5 is fixed to the back side of the case 6. Since the inserted portion 30 into which the connector connecting portion 25 is inserted is substantially parallel to the plate surface of the circuit board 4, when the flexible printed wiring board 5 is routed, there is no need to wind up (turn back) the flexible printed wiring board 5. The flexible printed wiring board 5 can be routed along the board surface of the circuit board 4, and the flexible printed wiring board 5 does not protrude on the back side of the circuit board 4. The liquid crystal display device can be thinned.

  In addition, since the fixing part 26 is an area where the electronic component 27 that drives the liquid crystal display 2 is mounted, the fixing part 26 of the flexible printed wiring board 5 that is most likely to shake when vibration is applied to the liquid crystal display device ( Since the region where the electronic component 27 is mounted is fixed, a vibration-resistant liquid crystal display device can be obtained.

  The present invention can be applied even when the liquid crystal display device is incorporated in a vehicle instrument device equipped with a speedometer, a tachometer, etc. In that case, the circuit board is integrated with the circuit board constituting the instrument device. There may be.

DESCRIPTION OF SYMBOLS 1 Liquid crystal display panel 2 Liquid crystal display 3 Connector 4 Circuit board 5 Flexible wiring board 17 Display panel connection part 25 Connector connection part 26 Fixing part 27 Electronic component 28 Notch part 30 Insertion part

Claims (3)

  A liquid crystal display provided with a liquid crystal display panel, a rigid circuit board disposed behind the liquid crystal display and having a connector mounted on the back side, a flexible printed wiring board connecting the liquid crystal display panel and the connector, The flexible printed wiring board includes a display panel connection portion connected to one end portion of the liquid crystal display panel, a connector connection portion connected to the connector, and a back surface of the liquid crystal display device. A fixing portion fixed to the side, and the circuit board has a notch portion for routing the flexible printed wiring board from the fixing portion to the connector connecting portion to the connector. Liquid crystal display device. Said connector, said together than the fixed portion which is fixed to the rear surface side of the liquid crystal display is mounted on 箇 office corresponding to the connector connecting portion closer, the insertion portion of the connector connecting portion is inserted the The liquid crystal display device according to claim 1, wherein the liquid crystal display device is substantially parallel to a plate surface of the circuit board.   The liquid crystal display device according to claim 1, wherein the fixing portion is a region where an electronic component that drives the liquid crystal display is mounted.

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