JP2007171361A - Display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display device capable of preventing a display panel and a surface light emitting device from peeling off each other owing to a reaction force due to bending of a flexible wiring board, thereby keeping the display brightness of the display panel appropriately. <P>SOLUTION: A pressure-sensitive adhesive sheet 22 is provided between a reverse surface side of the surface light emitting device 14 and a control board 12. This pressure-sensitive adhesive sheet 22 comprises a rectangular body area 22a and branch areas 22b projecting in a wing shape from the body area 22a to both sides. The branch areas 22b projects from the body area 22a closely to the flexible wiring board 13. The branch areas 22b are folded back from side edges while holding the surface light emitting device 14 and a liquid crystal display panel 11 inside, and stuck outside a display area 11a of the liquid crystal display panel 11. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a display device including a flexible wiring board that connects a display panel and a control board.

  In recent years, the use of small liquid crystal display devices (display devices) is expanding in small portable devices such as mobile phones, portable televisions, and portable game machines. A liquid crystal display device incorporated in these small portable devices includes a liquid crystal display panel and a control board on which an integrated circuit or the like for controlling the liquid crystal display panel is mounted. And these liquid crystal display panels and the control board are connected by the flexible wiring board which can be bent (for example, refer patent document 1).

In such a liquid crystal display device, a surface light emitting device (backlight) that illuminates the liquid crystal display panel is attached to the back side of the liquid crystal display panel with an adhesive sheet or the like, and a control board is attached to the back side of the surface light emitting device. It has a layer structure that is affixed with a sheet or the like. The flexible wiring board is bent by 180 °, and the liquid crystal display panel located in the upper and lower layers is connected to the control board via the surface light emitting device.
JP 2004-117659 A

  However, in the display device as described above, since the illumination light of the surface light emitting device is incident on the liquid crystal display panel, the liquid crystal display panel and the surface light emitting device are in close contact with each other by an adhesive sheet provided only at the peripheral portion. For this reason, since the surface light emitting device and the liquid crystal display panel having low adhesive strength because they are connected only at the peripheral portion connect the liquid crystal display panel positioned in the upper and lower layers and the control board via the surface light emitting device. The repulsive force (restoring force) of the flexible wiring board bent by 180 ° may cause a problem that the flexible wiring board is peeled off from the position near the flexible wiring board. If even part of the surface light-emitting device and the liquid crystal display panel are peeled off, the illumination light from the surface light-emitting device will not be incident on the liquid crystal display panel with uniform illuminance, resulting in uneven display brightness of the liquid crystal display panel and reduced visibility Problem arises.

  The present invention has been made in view of the above circumstances, and prevents the display panel and the surface light emitting device from being peeled off by the repulsive force caused by the bending of the flexible wiring board, and the display brightness of the display panel can be maintained appropriately. An object is to provide an apparatus.

  In order to achieve the above object, according to the present invention, a display panel for displaying an image, a control board on which electronic components for controlling the display panel are mounted, and the display panel and the control board are electrically connected. A display device comprising a flexible wiring board that can be flexibly connected and a surface light-emitting device that illuminates the display panel from the back side, the main body joining the back side of the light-emitting surface of the surface light-emitting device and the control board An adhesive sheet extending between the surface light emitting device and the control board is provided between the surface light emitting device and the control board. A display device is provided.

  The main body area | region of the said adhesive sheet should just be arrange | positioned with the adhesive material on both sides | surfaces, and the said branch area | region should just be arrange | positioned with the adhesive material on one side. The branch area of the adhesive sheet may be adhered to the outside of the display area of the display panel. In addition, at least the branch region of the pressure-sensitive adhesive sheet may be formed of a light shielding material.

  According to the display device of the present invention, even if a force that causes the back surface side of the liquid crystal display panel and the surface light emitting device to peel off due to the repulsive force caused by the bending of the flexible wiring board, the liquid crystal is formed by the branch region formed on the adhesive sheet. Since the display panel and the surface light-emitting device are fixed from the side edges, the liquid crystal display panel and the surface light-emitting device are reliably prevented from being separated near the flexible wiring board.

  In addition, since the branch region of such an adhesive sheet is adhered to the outside of the display region of the liquid crystal display panel, the display region is not hidden and the light of the surface light emitting device is transmitted to the entire display region of the liquid crystal display panel. Can be uniformly incident. This makes it possible to maintain good visibility of the liquid crystal display device without causing uneven brightness in the liquid crystal display panel.

  Hereinafter, a display device according to the present invention will be described with reference to the drawings. FIG. 1 is an external perspective view showing a liquid crystal display device which is an embodiment of the display device of the present invention. A liquid crystal display device (display device) 10 according to the present embodiment includes a liquid crystal display panel (display panel) 11 that displays images in order from the upper layer, and a surface light emitting device (backlight) 14 that illuminates the display panel 11 from the back surface. And a control board 12 on which electronic components for controlling the display panel 11 are placed. In addition, a flexible wiring substrate 13 that electrically connects the liquid crystal display panel 11 and the control substrate 12 is provided.

  2 is a cross-sectional view taken along line AA of the liquid crystal display device shown in FIG. 1, and FIG. 3 is an exploded perspective view of the liquid crystal display device. The liquid crystal display panel 11 has a known layer structure such as a liquid crystal layer or an electrode layer, and displays a predetermined image in the display area 11 a in accordance with a control signal output from the control substrate 12. The control board 12 has a control IC 12b mounted on the printed wiring board 12a, and outputs a control signal to the liquid crystal display panel 11 via the flexible wiring board 13 in accordance with an image signal to be displayed.

  The surface light emitting device (backlight) 14 includes a light guide plate made of, for example, a transparent resin, and a light source such as an LED that makes light incident on the light guide plate. Such a surface light-emitting device 14 irradiates illumination light uniformly from the light emitting surface 14a, and illuminates the liquid crystal display panel 11 from the back surface side.

  The flexible wiring board 13 is formed by forming a large number of conductive patterns made of a conductive thin film such as copper on a flexible resin film, and a liquid crystal display panel 11 and a control board positioned in upper and lower layers via a surface light emitting device 14. In order to connect 12, it is bent at approximately 180 ° (see FIG. 1).

  The back side of the liquid crystal display panel 11 and the surface light emitting device (backlight) 14 are connected by a double-sided adhesive tape 21 at the peripheral edge. A portion surrounded by the double-sided adhesive tape 21 is a light emitting surface 14 a of the surface light emitting device 14. In this way, by connecting the back side of the liquid crystal display panel 11 and the surface light emitting device (backlight) 14 only at the periphery, the illumination light of the surface light emitting device 14 is incident on the liquid crystal display panel 11 from the back side. Can do.

  On the other hand, an adhesive sheet 22 is provided between the back side of the surface light emitting device (backlight) 14 and the control board 12. The pressure-sensitive adhesive sheet 22 includes a rectangular main body region 22a and branch regions 22b projecting in a wing shape on both sides from the main body region 22a (see FIG. 3). The main body region 22a of the pressure-sensitive adhesive sheet 22 is formed with a pressure-sensitive adhesive material on both surfaces, and bonds the back surface side of the surface light emitting device 14 and the control board 12 over the entire surface.

  The branch region 22b protrudes from the main body region 22a near the flexible wiring board 13. The branch region 22b is formed with an adhesive material only on the upper surface side in FIG. 3 and is folded back so as to embrace the surface light emitting device 14 and the liquid crystal display panel 11 from the side edge. It sticks on the outer side of 11a (refer FIG. 1). With such a configuration, the liquid crystal display panel 11 and the surface light emitting device 14 are attached to the peripheral portion of the display area by the double-sided adhesive tape 21, and on the flexible wiring board 13 side by the branch area 22 b of the adhesive sheet 22. Fixed from the side edge.

  With the above-described configuration, even if a force that causes separation between the back surface side of the liquid crystal display panel 11 and the surface light emitting device (backlight) 14 due to a repulsive force caused by bending of the flexible wiring board 13 is formed on the adhesive sheet 22. Since the liquid crystal display panel 11 and the surface light emitting device 14 are fixed from the side edges by the wing-shaped branch region 22b, the liquid crystal display panel 11 and the surface light emitting device 14 are peeled off near the flexible wiring board 13. Is surely prevented.

  In addition, since the branch region 22b of the pressure-sensitive adhesive sheet 22 is attached to the outside of the display region 11a of the liquid crystal display panel 11, the display region is not hidden and the light of the surface light emitting device 14 is displayed on the liquid crystal display. The light can be uniformly incident on the entire display area 11 a of the panel 11. Thereby, the brightness of the liquid crystal display panel 10 can be kept good without causing uneven brightness on the liquid crystal display panel 11.

  In addition, by configuring the branch region 22b of the pressure-sensitive adhesive sheet 22 with a light-shielding sheet or the like, it is also possible to prevent the visibility from being deteriorated due to stray light entering from the outside of the display region 11a of the liquid crystal display panel 11. It is.

  As shown in FIG. 3, the liquid crystal display device (display device) 10 is assembled by first attaching the back surface side of the liquid crystal display panel 11 and the surface light emitting device (backlight) 14 with a double-sided adhesive tape 21 at the periphery. . Next, the flexible wiring substrate 13 is bent by 180 °, and the back surface side of the surface light emitting device 14 and the control substrate 12 are bonded to each other in the main body region 22 a of the adhesive sheet 22. Finally, the branch region 22b of the pressure-sensitive adhesive sheet 22 may be folded upward and attached to the outside of the display region 11a of the liquid crystal display panel 11. Moreover, in this embodiment, although the adhesive material was formed in the main body area | region and the branch area | region entirely, you may arrange | position an adhesive material partially, for example in frame shape and strip | belt shape.

  In the above-described embodiment, the liquid crystal display panel is used as the display panel. However, the display panel can be applied to various display devices having a flexible wiring board.

It is an external appearance perspective view which shows an example of the display apparatus of this invention. It is sectional drawing in the AA of FIG. It is a disassembled perspective view of the display apparatus of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Liquid crystal display device (display device), 11 ... Liquid crystal display panel (display panel), 12 ... Control board, 13 ... Flexible wiring board, 14 ... Surface light-emitting device (backlight), 22 ... Adhesive sheet, 22a ... Main body area | region , 22b ... branch region.

Claims (4)

A display panel for displaying an image, a control board on which electronic components for controlling the display panel are mounted, a flexible wiring board that can be bent to electrically connect the display panel and the control board, and a display panel A display device including a surface light emitting device that illuminates from the back side,
A pressure sensitive adhesive sheet comprising a main body region that joins the back side of the light emitting surface of the surface light emitting device and the control board, and a branch region that extends from the main body region and closely contacts the surface light emitting device and the display panel from a peripheral side. A display device provided between the surface light emitting device and the control board.   The display device according to claim 1, wherein an adhesive material is disposed on both side surfaces of the main body region of the adhesive sheet, and an adhesive material is disposed on one side surface of the branch region.   The display device according to claim 1, wherein the branch region of the adhesive sheet adheres to the outside of the display region of the display panel. The display device according to claim 1, wherein at least the branch region of the pressure-sensitive adhesive sheet is formed of a light-shielding material.

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