JP2008170691A - Liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make the quality of a liquid crystal display device high by protecting a liquid crystal display panel against external damage and improving the mechanical strength. <P>SOLUTION: The liquid crystal display device 100 includes the liquid crystal panel 1, a surface light source unit 2 disposed over the back of the liquid crystal display panel 1, a flexible circuit board 6 connected to the liquid crystal display panel 1, a PCB 3 disposed on the back of the surface light source unit 2 and connected to the liquid crystal display panel 1 through the flexible circuit board 6, and a cover unit 4 which has a first side 4a fixed to the surface light source unit 2 and a second side 4b extended and arranged to form a gap portion with the liquid crystal display panel 1 from the back of the PCB 3 to a side edge side of the liquid crystal display panel 1, where the flexible circuit board 6 is connected to a portion of a side edge of the liquid crystal display panel 1 and a protection member 15a formed to support the cover portion 4 on the side of the second side 4b is disposed in the gap portion where the flexible circuit board 6 is not arranged. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a liquid crystal display device.

  In recent years, liquid crystal display devices have been widely used as monitors for portable communication terminals, game machines, and the like. FIG. 4 is a partially cutaway sectional view of a main part of a conventional liquid crystal display device. As shown in FIG. 4, the liquid crystal display device includes a liquid crystal display panel 201, a surface light source unit 202 superimposed on the back surface of the liquid crystal display panel 201, and a PCB (Printed Circuit Board) disposed on the back surface of the surface light source unit 202. : Printed circuit board) 203 and a metal cover portion 204 disposed so as to cover the PCB 203 from the back side in order to protect the PCB 203 (see, for example, Patent Document 1).

  In the liquid crystal display panel 201, liquid crystal is disposed between two glass substrates 201a and 201b, and polarizing plates 201c and 201d are disposed on the front side (outer side) of the glass substrate 201a and the back side of the glass substrate 201b, respectively. Is provided. The liquid crystal display panel 201 and the PCB 203 are connected via a flexible circuit board 206 on which a driving IC (Integrated Circuit) 205 is mounted.

  The surface light source unit 202 is disposed on a light source 210 such as an LED (Light Emitting Diode), a light guide 211 that converts light from the light source 210 into planar light, and a front surface side (liquid crystal display panel side) of the light guide 211. Optical sheet 212, a reflection sheet 213 disposed on the back side of the light guide 211, a metal frame 214 that covers the light source 210, the light guide 211, the optical sheet 212, and the reflection sheet 213 from the back side, Consists of.

  The frame 214 has a front frame portion 214 a formed along the outer periphery on the front surface side of the surface light source unit 202, and a back frame portion 214 b formed on the side surface side and the back surface side. A spacer 215 having a rectangular vertical cross section is provided in a gap between the glass substrate 201b and the front frame portion 214a of the surface light source unit 202. The liquid crystal display panel 201 is fixed to the surface light source unit 202 by a double-sided tape 216 provided on the front surface and the back surface of the spacer 215.

The first side 204a of the cover unit 204 is fixed to the back surface of the surface light source unit 202 by screwing or bonding means, and the second side 204b is near the side edge of the liquid crystal display panel 201 (the flexible circuit board 206 is It is open in the vicinity of where it is located).
JP 2006-171388 A

  However, in the conventional liquid crystal display device shown in FIG. 4, since the second side 204b of the cover part 204 is opened without being supported, vibration may occur depending on the stress of the cover part 204, the dimensions of the member, the mounting position, and the like. During the test or the like, the cover portion 204 may come into contact with the vicinity of the side edge of the liquid crystal display panel 201 and the liquid crystal display panel 201 may be chipped. Moreover, the positioning of the cover part 204 may be incomplete, and the external dimensions may be exceeded. Furthermore, when the metal cover portion 204 comes into contact with the circuit portion of the liquid crystal display panel 201, the continuity becomes unstable, and display defects such as flickering and non-lighting may occur.

  In order to protect the liquid crystal display panel from external damage, there is a method of providing a frame along the side and back of the liquid crystal display panel. However, in the case of a liquid crystal display panel with a narrow frame such as a portable communication terminal, there is a space for providing the frame. Since the frame is narrow, there is a problem in that the thickness of the frame becomes thin, so that the parts cannot be held due to the broken frame, resulting in insufficient strength. Further, when the frame is not provided, the liquid crystal display panel is exposed, and the member may be chipped or scratched due to contact with other members.

  As described above, the conventional liquid crystal display device has a problem in that the quality of the liquid crystal display device is deteriorated due to insufficient protection of the liquid crystal display panel and insufficient mechanical strength.

  An object of the present invention is to improve the quality of a liquid crystal display device by protecting the liquid crystal display panel from external damage and improving the mechanical strength.

  The liquid crystal display device of the present invention includes a liquid crystal display panel, a surface light source unit arranged to be overlapped on the back surface of the liquid crystal display panel, and a flexibility connected to the liquid crystal display panel and bent to the back side of the surface light source unit. A circuit board, a printed circuit board disposed on the back surface of the surface light source unit and connected to the liquid crystal display panel via the flexible circuit board, and a first side fixed to the surface light source unit; A cover portion having a second side extending from the back surface of the printed circuit board to the side edge side of the liquid crystal display panel so as to form a gap with the liquid crystal display panel; The liquid crystal display panel is placed between the second side of the part and the surface light source part, and supports at least one of the inside of the second side of the cover part or the surface of the flexible circuit board. Protective member is placed And said that you are.

  According to the present invention, the protective member is provided in the gap between the cover and the liquid crystal display panel, thereby protecting the liquid crystal display panel from external damage and improving the mechanical strength. Quality can be improved.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the drawings referred to below are schematic, and the ratio of dimensions between the components is different from the actual one.

  FIG. 1 shows a top perspective view of a liquid crystal display device 100 according to an embodiment of the present invention, FIG. 2 shows an elevational sectional view taken along the line II-II in FIG. 1, and FIG. Fig. 3 shows an elevational sectional view as seen from the arrow III.

  As shown in FIGS. 1 to 3, the liquid crystal display device 100 includes a liquid crystal display panel 1, a surface light source unit 2 superimposed on the back surface of the liquid crystal display panel 1, and a PCB disposed on the back surface of the surface light source unit 2. (Printed Circuit Board: Printed Circuit Board) 3 and a metal cover portion 4 disposed so as to cover the PCB 3 from the back side.

  In the liquid crystal display panel 1, liquid crystal is disposed between two glass substrates 1a and 1b, and polarizing plates 1c and 1d are disposed on the front side (outside) of the glass substrate 1a and the back side of the glass substrate 1b, respectively. Is provided. In FIG. 1, the polarizing plate 1c is omitted.

  The liquid crystal display panel 1 and the PCB 3 are connected via a flexible circuit board 6. The flexible circuit board 6 is a flexible circuit board such as COF (Chip On Film), FPC (Flexible Printed Circuit), etc., as shown in FIG. 1, near the center of one side edge of the liquid crystal display panel 1 It is connected to the. FIG. 2 is an elevational sectional view of a portion where the flexible circuit board 6 is not disposed, and FIG. 3 is an elevational sectional view of a portion where the flexible circuit board 6 is disposed.

  As shown in FIG. 3, a driving IC (Integrated Circuit) 5 is sealed with a resin 7 on the flexible circuit board 6. A double-sided tape 19 is provided between the drive IC 5 and the PCB 3, and the drive IC 5 is fixed to the PCB 3 by the double-sided tape 19.

  In the present embodiment, a single flexible circuit board 6 is used. However, a plurality of flexible circuit boards 6 are connected at a predetermined interval along one side edge of the liquid crystal display panel 1. The part where the flexible circuit board 6 is not disposed and the part where the flexible circuit board 6 is disposed may be configured as shown in FIGS.

  The glass substrate 1b of the liquid crystal display panel 1 has a protruding portion 1e with one side surface protruding outward (the cover portion 4 side). As shown in FIG. 3, the flexible circuit board 6 has an ACF (Anisotropic Conductive Film) on one side 6a of a connection pad (not shown) formed near the center of the front surface of the protruding portion 1e of the glass substrate 1b. 3 portions 6c and 6d between the PCB 3 and the cover portion 4 that are connected using an anisotropic conductive film and are bent along the shape of a protective member 15b (described later) formed near the side surface of the overhang portion 1e. 6e, and the other side 6b is connected to a connection pad (not shown) formed on the front surface (the liquid crystal display panel side) of the PCB 3 using solder.

  The surface light source unit 2 includes a light source 10 such as an LED (Light Emitting Diode) mounted on a flexible substrate 20, a light guide 11 that converts light from the light source 10 into planar light, and a light guide 11. The optical sheet 12 disposed on the front side of the light source, the reflection sheet 13 disposed on the back side of the light guide 11, and the metal that covers the light source 10, the light guide 11, the optical sheet 12, and the reflection sheet 13 from the back side Frame 14.

  The frame 14 has a front frame portion 14 a formed along the outer periphery on the front surface side of the surface light source portion 2, and a back frame portion 14 b formed on the side surface side and the back surface side of the surface light source portion 2. An insulating tape 17 is attached to the outer surface of the frame 14 to prevent energization from the vicinity of the joint between the front frame portion 14a and the back frame portion 14b along the opposing surface of the PCB 3. The surface light source unit 2 to which the insulating tape 17 is attached and the one side 6b or the PCB 3 of the flexible circuit board 6 are fixed by a double-sided tape 18.

  The first side 4a of the cover unit 4 is fixed to the back surface of the surface light source unit 2 by screwing or bonding means, and the second side 4b of the cover unit 4 extends from the back side of the PCB 3 to the side edge side of the liquid crystal display panel 1 ( The liquid crystal display panel 1 is extended and arranged so that a gap is formed up to the vicinity of the overhanging portion 1e).

  Protective members 15a and 15b made of a resin having a light shielding property are provided between the liquid crystal display panel 1 and the cover portion 4. As shown in FIG. 1, the protection member 15b is provided in the portion where the flexible circuit board 6 is disposed as described above, and the protection member 15a is the flexible circuit board of the protruding portion 1e of the glass substrate 1b. 6 is provided in the part (two places in FIG. 1) where it is not arranged.

  As shown in FIG. 2, the protection member 15 a is larger than the thickness of the glass substrate 1 b so as to protrude from the flat portion 21 and the front end side of the liquid crystal display panel 1 orthogonal to the flat portion 21. The projecting portion 22 is formed, and a step portion is formed between the projecting portion 22 and the flat portion 21. The flat part 21 is disposed in a gap between the protruding part 1e of the glass substrate 1b and the front frame part 14a of the surface light source part 2, and the liquid crystal display panel 1 is placed on the step part. The protruding portion 22 is formed in a gap between the side surface of the protruding portion 1e of the glass substrate 1b and the cover portion 4, protrudes from the protruding portion 1e toward the cover portion 4 and fills the gap portion. 4 has a shape along the inner surface. The second side 4 b of the cover part 4 is supported by at least a part of the outer surface of the protruding part 22 contacting the cover part 4. By the protective member 15a having such a configuration, the vertical and horizontal movements of the cover part 4 are suppressed, and the second side 4b of the cover part 4 can be prevented from coming into contact with the liquid crystal display panel 1.

  Similarly to the protection member 15a, the protection member 15b has a flat portion 23 and a guide portion 24 (corresponding to the protruding portion 22 of the protection member 15a) as shown in FIG. However, the height of the guide portion 24 is set lower than that of the protruding portion 22, and the height of the step portion constituted by the flat portion 23 and the guide portion 24 substantially corresponds to the thickness of the glass substrate 1b. It is set to height. The flat part 23 is disposed in a gap between the protruding part 1e of the glass substrate 1b and the front frame part 14a of the surface light source part 2, and the glass substrate 1b is placed on the stepped part. The guide portion 24 is formed in a gap between the side surface of the protruding portion 1 e of the glass substrate 1 b and the cover portion 4 and has a shape that guides the routing of the flexible circuit board 6. Specifically, in order to prevent damage to the flexible circuit board 6 that comes into contact, the contact surface with the flexible circuit board 6 is preferably curved. And it is made so that an unnecessary stress may not be added to the connection place of the flexible circuit board 6 and the glass substrate 1b by forming so that the front-end | tip of the guide part 24 and the glass substrate 1b surface may become planar shape. Is preferred. Further, a gap is left between the guide part 24 and the cover part 4 so that the flexible circuit board 6 disposed along the guide part 24 does not contact the cover part 4.

  Between the glass substrate 1b and the front frame part 14a of the surface light source part 2, in addition to the protection members 15a and 15b arranged along the overhanging part 1e, as shown in FIG. 1, other than the overhanging part 1e A spacer 15c is arranged along the outer periphery of the. A double-faced tape 16 is provided on the front and back surfaces of the protective member 15a, the protective member 15b, and the spacer 15c. Fixed horizontally.

  As described above, according to the liquid crystal display device 100 of the present embodiment, the liquid crystal display panel 1 is externally damaged by providing the protective members 15 a and 15 b in the gap between the cover 4 and the liquid crystal display panel 1. It is possible to improve the mechanical strength and improve the quality of the liquid crystal display device 100.

  In particular, the protective member 15a provided in the portion where the flexible circuit board 6 is not disposed fills the gap between the cover portion 4 and the liquid crystal display panel 1, and covers the second side 4b of the cover portion 4. By having a shape to support, even in a vibration test or the like, the movement of the cover portion 4 in the vertical and horizontal directions is suppressed, and the cover portion 4 does not come into contact with the liquid crystal display panel 1 and the display as conventionally generated is possible. Problems can be prevented.

  In addition, the protective member 15b provided in the portion where the flexible circuit board 6 is disposed has a shape that guides the flexible circuit board 6, so that the lead connected to the liquid crystal display panel 1 is provided. It is difficult to apply stress to the portion (not shown), and display defects due to disconnection of the lead portion can be prevented.

  Furthermore, by using a light-shielding member as the protective members 15a and 15b, it is possible to block light leaking from the side surface of the liquid crystal display panel 1, and to prevent display defects due to light leakage.

  Further, by disposing the planar portion 21 of the protective member 15a and the planar portion 23 of the protective member 15b in the gap between the glass substrate 1b of the liquid crystal display panel 1 and the front frame portion 14a of the surface light source unit 2, The protection members 15a and 15b can function as spacers as in the past.

  Note that the description in the present embodiment can be changed as appropriate without departing from the spirit of the present invention.

  For example, instead of the protective member 15b (see FIG. 3) provided in the portion where the flexible circuit board 6 is disposed, a spacer 215 having a rectangular cross section as shown in FIG. 4 may be provided. Good. In this case, the liquid crystal display panel 1 is protected by the protective member 15a (see FIG. 2) provided in a portion where the flexible circuit board 6 is not provided, but does not have the guide function of the flexible circuit board 6. The effect and mechanical strength are sufficiently secured.

1 is a schematic top perspective view showing a liquid crystal display device according to an embodiment of the present invention. Fig. 2 is a vertical sectional view taken along the line II-II in Fig. 1. Fig. 3 is a vertical sectional view taken along the line III-III in Fig. 1. The partially cutaway sectional view of the main part of the conventional liquid crystal display device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Liquid crystal display panel 1a, 1b Glass substrate 1c, 1d Polarizing plate 2 Surface light source part 3 PCB
4 Cover portion 4a First side 4b Second side 5 Drive IC
6 Flexible circuit board 10 Light source 11 Light guide 12 Optical sheet 13 Reflective sheet 14 Frame 14a Front frame part 14b Back frame parts 15a and 15b Protection member 15c Spacers 21 and 23 Planar part 22 Projection part 24 Guide part 100 Liquid crystal display device

Claims (4)

A liquid crystal display panel;
A surface light source unit superimposed on the back surface of the liquid crystal display panel;
A flexible circuit board connected to the liquid crystal display panel and bent to the back side of the surface light source unit;
A printed circuit board disposed on the back surface of the surface light source unit and connected to the liquid crystal display panel via the flexible circuit board;
The first side fixed to the surface light source unit and the back side of the printed circuit board to the side edge side of the liquid crystal display panel are arranged to extend so as to form a gap between the liquid crystal display panel and the first side. A cover portion having a second side,
The liquid crystal display panel is placed between the second side of the cover part and the surface light source part, and at least one of the inner side of the second side of the cover part or the surface of the flexible circuit board is provided. A liquid crystal display device, wherein a protective member to be supported is disposed.   The protective member includes a flat portion and a protruding portion, the flat portion is disposed in a gap between the liquid crystal display panel and the surface light source portion, and the protruding portion is one glass substrate constituting the liquid crystal display panel. The liquid crystal display device according to claim 1, wherein the liquid crystal display device protrudes outward and is brought into contact with the cover portion.   The protective member includes a flat portion and a protruding portion, the flat portion is disposed in a gap between the liquid crystal display panel and the surface light source portion, and the protruding portion is connected to the flexible circuit board. The liquid crystal display device according to claim 1, wherein the liquid crystal display device is projected to substantially the same height as a glass substrate constituting the panel, and the flexible circuit board is guided along an outer surface of the protruding portion.   The liquid crystal display device according to claim 1, wherein the protective member has a light shielding property.

Images