JP2010276934A - Liquid crystal display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a break in bending of a flexible wiring board which is stuck to a first substrate of a liquid crystal display panel. <P>SOLUTION: The liquid crystal display includes: a liquid crystal display panel having a first substrate and a second substrate; a backlight disposed on the rear side of the liquid crystal display panel; and the flexible wiring board connected with the first substrate, wherein the backlight has a frame-shaped mold, the first substrate has non-overlapping region not overlapping with the second substrate, the flexible wiring board is connected with an edge of the non-overlapping region of the first substrate, the flexible wiring board is bent and a portion thereof is placed on the rear side of the frame-shaped mold, the mold has a protrusion on a face of the liquid crystal display panel side of an edge parallel to the one edge of the non-overlapping region of the first substrate, and the height of the protrusion is lower than a contact face of the first substrate and the flexible wiring board. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a liquid crystal display device, and more particularly to a technique effective when applied to a backlight that houses a light guide plate, an optical sheet group, and the like.

A liquid crystal display device (also referred to as a liquid crystal display module) having a small TFT (Thin Film Transistor) type liquid crystal display panel is widely used as a display portion of a mobile device such as a mobile phone.
In general, a liquid crystal display device includes a liquid crystal display panel and a backlight that irradiates light to the liquid crystal display panel. It is comprised with a mold (henceforth a mold), the optical sheet group arrange | positioned inside a mold, a light-guide plate, and the reflective sheet arrange | positioned under a light-guide plate. The liquid crystal display panel includes a first substrate (for example, a glass substrate), a second substrate, and a liquid crystal sandwiched between the first substrate and the second substrate.
That is, a liquid crystal display device for a cellular phone has a structure in which a first substrate constituting a liquid crystal display panel is bonded and fixed to a frame-shaped mold so that light from a lower backlight is transmitted. Here, a semiconductor chip constituting a driver IC that drives liquid crystal and a flexible wiring board (FPC) that transfers power and video data are bonded to the first substrate via an anisotropic conductive film.

JP 2007-25484 A

The flexible printed circuit board (FPC) bonded to the first substrate of the liquid crystal display panel may be used as it is, but in general, in a mobile phone or the like having a small vertical dimension, FIG. As shown in FIG. 5, the flexible wiring board is often used by being bent on the back side of the liquid crystal display device.
4 is a plan view of a conventional liquid crystal display device, and FIG. 5 is a cross-sectional view showing a cross-sectional structure taken along the line AA ′ of FIG. 4 and 5, 1 is an upper polarizing plate, 2 is a second substrate (also referred to as a CF substrate), 3 is a first substrate (also referred to as a TFT substrate), 4 is a semiconductor chip, and 5 is a flexible wiring substrate (hereinafter, referred to as “a substrate”). FPC), 6 is a resin frame mold (hereinafter referred to as a mold), 8 is a light shielding tape, 9 is a reflection sheet, 10 is a light guide plate, 11 is an optical sheet group, 12 is a lower polarizing plate, 13 is a spacer tape, 14 Is a flexible wiring board for light source (hereinafter referred to as LED-FPC), 15 is a fixing tape, and 16 is a lower frame.
When the FPC 5 is bent to the back side of the liquid crystal display device, the FPC 5 is generally wound around the side wall of the mold 6 and bent. Therefore, when the folding position is close to the end of the first substrate, as shown in FIG. 5, the FPC 5 protruding from the end of the first substrate (for example, glass substrate) is wound around the mold 6 so as to be bent obliquely downward. Become. Since the end surface of the first substrate 3 functions like a blade, the slanted FPC 5 comes into contact with the end of the first substrate 3 as shown in FIG. Cause.
The present invention has been made to solve the above-described problems of the prior art, and an object of the present invention is to prevent disconnection at the time of bending of a flexible wiring substrate bonded to a first substrate of a liquid crystal display panel. It is to provide a technology that makes it possible.
The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

Of the inventions disclosed in this application, the outline of typical ones will be briefly described as follows.
(1) A liquid crystal display comprising a liquid crystal display panel having a first substrate and a second substrate, a backlight disposed on the back side of the liquid crystal display panel, and a flexible wiring substrate connected to the first substrate. The backlight includes a frame-shaped mold, the first substrate includes a non-overlapping region that does not overlap with the second substrate, and the flexible wiring substrate includes the first substrate. Connected to one side of the non-overlapping region, the flexible wiring board is bent and a part of the flexible wiring substrate is disposed on the back side of the frame-shaped mold, and the mold is formed on the non-overlapping region of the first substrate. A protrusion is provided on a surface of the side wall parallel to one side on the liquid crystal display panel side, and the height of the protrusion is lower than the contact surface between the first substrate and the flexible wiring substrate.
(2) In (1), the corners of the protrusions formed on the mold that are in contact with the flexible wiring board are chamfered.
(3) In (1), a corner portion of the side wall parallel to one side of the non-overlapping area of the first substrate of the mold on the side opposite to the liquid crystal display panel is chamfered. It has been subjected.
(4) In any one of (1) to (3), the protrusion of the mold has a width equal to or greater than ¼ of the width of the bent portion of the flexible wiring board.

(5) In any one of (1) to (4), a part of the side wall parallel to one side of the non-overlapping region of the first substrate of the mold has a low height region, The protrusion is provided in the low height region of the side wall parallel to one side of the non-overlapping region of the first substrate, and the protrusion of the mold is one side of the non-overlapping region of the first substrate. The first side wall and the second side wall are formed with a first and second gaps between the side wall and the portion other than the lower region.
(6) In (5), the first distance between the protrusion of the mold and a portion of the side wall parallel to one side of the non-overlapping region of the first substrate other than the low region. Has a groove into which the lead-out portion of the light source wiring board on which the light source for the backlight is mounted is inserted.
(7) In (6), the light source for the backlight is a white light emitting diode.
(8) In (6) or (7), the lead-out portion of the light source wiring board is bent, and a part thereof is disposed on the back side of the frame-shaped mold. The part is connected to a part of the flexible wiring board on the back side of the frame-shaped mold.
(9) In any one of (1) to (8), it has a lower frame that houses the mold, the lower frame has an opening through which the flexible wiring board passes, and the flexible wiring board A part of the lower frame is disposed on the back side of the lower frame through the opening.

The effects obtained by the representative ones of the inventions disclosed in the present application will be briefly described as follows.
ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to prevent the disconnection at the time of bending of the flexible wiring board adhere | attached on the 1st board | substrate of a liquid crystal display panel.

It is a disassembled perspective view which shows the liquid crystal display device of the Example of this invention. It is sectional drawing which shows the cross-section of the liquid crystal display device of the Example of this invention. It is a figure for demonstrating the mold of the Example of this invention. It is a top view of the conventional liquid crystal display device. FIG. 5 is a cross-sectional view showing a cross-sectional structure taken along the line A-A ′ of FIG. 4.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
In all the drawings for explaining the embodiments, parts having the same functions are given the same reference numerals, and repeated explanation thereof is omitted.
FIG. 1 is an exploded perspective view showing a liquid crystal display device according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view showing a cross-sectional structure of the liquid crystal display device according to the embodiment of the present invention. 2 is a cross-sectional view showing a cross-sectional structure at the same location as FIG. In addition, the top view of the liquid crystal display device of a present Example is the same as FIG.
1 and 2, 1 is an upper polarizing plate, 2 is a second substrate (also referred to as a CF substrate), 3 is a first substrate (also referred to as a TFT substrate), 4 is a semiconductor chip, and 5 is a flexible wiring substrate (hereinafter referred to as “a wiring board”). FPC), 6 is a resin frame mold (hereinafter referred to as a mold), 8 is a light shielding tape, 9 is a reflection sheet, 10 is a light guide plate, 11 is an optical sheet group, 12 is a lower polarizing plate, 13 is a spacer tape, 14 Is a flexible wiring board for light source (hereinafter referred to as LED-FPC), 15 is a fixing tape, and 16 is a lower frame.
The liquid crystal display panel LCD of this embodiment has a first substrate 3, a second substrate 2, a liquid crystal layer (not shown) sandwiched between the first substrate 3 and the second substrate 2, and a drive circuit. The mounted semiconductor chip 4, the FPC 5 connected to one side of the first substrate 3, the lower polarizing plate 12 attached on the first substrate 3, and the upper polarization attached on the second substrate 2 Plate 1. Here, the opposite side of the liquid crystal layer of the second substrate 2 is the observer side.

As the first and second substrates (2, 3), for example, transparent insulating substrates such as glass are used. The long side of the first substrate 3 is longer than the long side of the second substrate 2, and the first substrate 3 has a configuration that does not overlap with the second substrate 2 (hereinafter referred to as a non-overlapping region). The semiconductor chip 4 is mounted in a non-overlapping region on the surface of the first substrate 3 on the liquid crystal layer side.
Thin film transistors, pixel electrodes, and the like are formed on the first substrate 3, and color filters and the like are formed on the second substrate 2. Here, in the case of an IPS liquid crystal display panel, the counter electrode is provided on the first substrate 3 side. In the case of a TN or VA liquid crystal display panel, the counter electrode is provided on the second substrate 2 side.
The backlight BL includes a mold 6, a light guide plate 10, an optical sheet group 11, a reflection sheet 9, and a lower frame 16.
As shown in FIG. 1, the light guide plate 10 is disposed in the mold 6, and the optical sheet group 11 is disposed on the light guide plate 10. A reflective sheet 9 is disposed below the light guide plate 10. Further, a lower frame 16 is disposed below the mold 6. Here, the optical sheet group 11 includes, for example, a lower diffusion sheet, two lens sheets, and an upper diffusion sheet.

A white light emitting diode (not shown) that functions as a light source is disposed on one side of the light guide plate 10. In FIG. 1, the white light emitting diode is mounted on the lower side of the LED-FPC 14.
The elongated lead-out portion 14A of the LED-FPC 14 is drawn out from the groove portion 31 formed in the side wall 6A parallel to the short side of the non-overlapping region of the first substrate 3 of the mold 6 and bent to the back side of the liquid crystal display device. .
The elongated lead-out portion 14A of the LED-FPC 14 is bent to the back side of the liquid crystal display device, and similarly connected to the FPC 5 bent to the back side of the liquid crystal display device. FIG. 4 shows a state where the lead-out / drawing portion 14A of the LED-FPC 14 is bent.
As shown in FIG. 1, the white light emitting diode mounted on the LED-FPC 14 is disposed on one side surface of the light guide plate 10 from the upper side.
The mold 6 is also formed with a support portion 6B for supporting the first substrate 3 of the liquid crystal display panel LCD. The LED-FPC 14 is provided on the support portion 6B in the non-overlapping region portion of the first substrate 3. A stepped portion 6C for mounting is formed. Further, the step portion 6C is formed with a recess 6D into which the white light emitting diode is inserted.
In the present embodiment, the LED-FPC 14 is fixed to the step portion 6 </ b> C of the mold 6 by the fixing tape 15. Further, the light shielding tape 8 is bonded to the region where the LED-FPC 14 is mounted on the first substrate 3 of the liquid crystal display panel LCD. A spacer tape 13 is disposed between the light shielding tape 8 and the LED-FPC 14. The spacer tape 13 is provided to adjust the distance between the liquid crystal display panel LCD and the step portion 6C of the mold 6 or the light guide plate 10, and is not necessarily required.

FIG. 3 is a view for explaining a portion of a region where the LED-FPC 14 is mounted in the mold 6 of this embodiment, and FIG. 3A is a side view (viewed from the direction of arrow A in FIG. 1). FIG. 3 and FIG. 3B are front views.
As shown in FIGS. 1 and 3, the mold 6 has a side wall 6 </ b> A around the mold 6. In this embodiment, the mold 6 has a low height on a part of the side wall 6 </ b> A parallel to one side of the non-overlapping region of the first substrate 3. The protrusion 30 is provided in a region having a region and having a low side wall parallel to one side of the non-overlapping region of the first substrate 3.
As a result, as shown in FIG. 2, in this embodiment, the FPC 5 that has exited the end of the first substrate of the liquid crystal display panel LCD reaches the protrusion 30 of the mold 6 in parallel with the first substrate 3. Since it is bent at a portion away from the end, in this embodiment, it is possible to avoid contact between the FPC 5 and the first substrate end, and thus it is possible to prevent disconnection of the wiring on the FPC 5.
As shown in FIG. 3, the protruding portion 30 has a first interval (T1 in FIG. 3) between a portion other than the low height region of the side wall 6A parallel to one side of the non-overlapping region of the first substrate 3. ) And a second interval (T2). Then, in the second interval (T2), a groove portion 31 into which the elongated lead-out portion 14A of the LED-FPC 14 is inserted is formed.

When the height of the protrusion 30 (H in FIG. 3) is higher than the contact surface between the first substrate 3 and the FPC 5, an upward force is applied to the FPC 5, so that the FPC 5 is peeled off from the connection portion with the first substrate 3. There is a fear. Therefore, the height of the protrusion 30 (H in FIG. 3) needs to be lower than the contact surface between the first substrate 3 and the FPC 5.
The height of the protrusion 30 (H in FIG. 3) is also related to the distance from the end of the first substrate to the bending position of the FPC 5, and therefore the height of the protrusion 30 (H in FIG. 3) is It is necessary to determine appropriately according to the distance from the end of the first substrate to the bending position of the FPC 5 that is lower than the contact surface between the first substrate 3 and the FPC 5.
In the present embodiment, as shown in FIG. 2, the corner portion with which the FPC 5 of the protrusion 30 abuts, and the protrusion 30 of the side wall 6 </ b> A parallel to the short side of the non-overlapping region of the first substrate 3 of the mold 6 The corner portion with which the FPC 5 abuts on the opposite side is chamfered, thereby preventing the FPC 5 from being bent at an acute angle and preventing the wiring on the FPC 5 from being disconnected.
In addition, if the width of the protrusion 30 is too narrow, the portion having no protrusion is not effective and cannot be supported, and the FPC 5 may be damaged when bent in reverse. What is necessary is just to have the above width (W of FIG. 3). Since the width of the bent portion of the FPC 5 is about 20 mm at the minimum, the protrusion 30 should have a width (W in FIG. 3) that is at least 1/4 of the width of the bent portion of the FPC 5. That's fine.

As shown in FIG. 1, the lower frame 16 includes a bottom surface 16A and side walls 16B provided around the bottom surface 16A. An opening 33 is formed on the bottom surface 16 </ b> A of the lower frame 16.
In addition, as shown to 16C of FIG. 1, the side wall 6A parallel to one side of the non-overlapping area | region of the 1st board | substrate 3 of the lower flame | frame 16 is formed only in both ends, and is a part corresponding to the bending part of center FPC5 Is not formed. Thereby, when the FPC 5 is bent, the FPC 5 abuts against the side wall 16A of the lower frame 16, the FPC 5 is prevented from being bent at an acute angle, and the wiring on the FPC 5 is prevented from being disconnected.
As shown in FIG. 2, the FPC 5 passes through the opening 33 formed in the bottom surface 16 </ b> A of the lower frame 16, and a part thereof is disposed on the back side of the lower frame 16. Similarly, although not shown, the elongated lead-out portion 14A of the LED-FPC 14 also passes through the opening 33 formed in the bottom surface 16A of the lower frame 16, and a part thereof is disposed on the back side of the lower frame 16. .
As mentioned above, the invention made by the present inventor has been specifically described based on the above embodiments. However, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the invention. Of course.

1 Upper polarizing plate 2 Second substrate (CF substrate)
3 First substrate (TFT substrate)
4 Semiconductor chip 5 Flexible printed circuit board (FPC)
6 resin frame mold 6A side wall 6B support portion 6C stepped portion 6D recessed portion 8 light shielding tape 9 reflecting sheet 10 light guide plate 11 optical sheet group 12 lower polarizing plate 13 spacer tape 14 flexible wiring board for light source (LED-FPC)
14A Drawer 15 Fixing tape 16 Lower frame 16A Bottom 16B Side wall 30 Protrusion 31 Groove 33 Opening LCD LCD LCD panel B / L Backlight

Claims (10)

A liquid crystal display panel having a first substrate and a second substrate;
A backlight disposed on the back side of the liquid crystal display panel;
A liquid crystal display device comprising a flexible wiring substrate connected to the first substrate,
The backlight has a frame-shaped mold,
The first substrate has a non-overlapping region that does not overlap with the second substrate;
The flexible wiring board is connected to one side of the non-overlapping region of the first board,
The flexible wiring board is bent and a part thereof is arranged on the back side of the frame-shaped mold,
The mold has a protrusion on a surface on the liquid crystal display panel side of a side wall parallel to one side of the non-overlapping region of the first substrate,
The liquid crystal display device, wherein a height of the protrusion is lower than a contact surface between the first substrate and the flexible wiring substrate.   2. The liquid crystal display device according to claim 1, wherein a corner portion of the protruding portion formed on the mold with which the flexible wiring substrate abuts is chamfered.   The corner of the side of the mold that is parallel to one side of the non-overlapping region of the first substrate on the side opposite to the liquid crystal display panel is chamfered at the corner where the flexible wiring board abuts. The liquid crystal display device according to claim 1.   4. The liquid crystal display device according to claim 1, wherein the protrusion of the mold has a width equal to or greater than ¼ of a width of a bent portion of the flexible wiring board. 5. In a part of the side wall parallel to one side of the non-overlapping region of the first substrate of the mold, a region having a low height is provided.
The protrusion of the mold is provided in the low region of the side wall parallel to one side of the non-overlapping region of the first substrate,
The protrusion of the mold is formed with a first and second gap between a portion of the side wall parallel to one side of the non-overlapping region of the first substrate other than the low-height region. The liquid crystal display device according to claim 1, wherein the liquid crystal display device is a liquid crystal display device.   The first interval between the protrusion of the mold and a portion of the side wall of the first substrate other than the low-height region parallel to one side of the non-overlapping region is for the backlight. 6. The liquid crystal display device according to claim 5, further comprising a groove into which a lead portion of the light source wiring board on which the light source is mounted is inserted.   The liquid crystal display device according to claim 6, wherein the light source for the backlight is a white light emitting diode. The lead-out portion of the light source wiring board is bent and a part thereof is disposed on the back side of the frame-shaped mold,
8. The liquid crystal display device according to claim 6, wherein the lead-out portion of the light source wiring board is connected to a part of the flexible wiring board on a back side of the frame-shaped mold. . A lower frame for housing the mold;
The lower frame has an opening through which the flexible wiring board passes,
9. The flexible wiring board according to claim 1, wherein a part of the flexible wiring board passes through the opening of the lower frame and is disposed on the back side of the lower frame. The liquid crystal display device described.   10. The liquid crystal display device according to claim 1, wherein a semiconductor chip is mounted on the non-overlapping region of the first substrate. 11.

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