JP2007034148A - Display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display device which is free from cracks regardless of bend of a flexible printed board connecting a display panel and a control substrate. <P>SOLUTION: Many conductive patterns 22 are formed between a positioning mark 23a and a positioning mark 23b on a flexible printed board 13. A plurality of dummy conductive patterns 25 extending from the vicinity of the positioning marks 23a and 23b toward the control substrate with a certain length are formed in gaps A from the outside of the conductive patterns 22 to both sides of a resin film 21. <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 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 this flexible wiring board, a large number of conductive patterns for electrically connecting the display panel and the control board are formed on a flexible resin film, and the flexible wiring board and the liquid crystal display panel are formed on both side ends thereof. Positioning marks for accurately aligning the two are formed, and the flexible wiring board and the liquid crystal display panel are fixed while aligning with the positioning marks and a panel positioning mark of a liquid crystal display panel (not shown). The conductive pattern is formed so as to pass between the positioning marks formed on both side ends of the flexible wiring board. When such a display device is incorporated into a device, the flexible wiring board is bent on the display panel side with respect to the positioning mark, and the display panel and the control board are incorporated so as to overlap each other.
JP 2004-117659 A

  However, when the flexible wiring board is bent in order to overlap the display panel and the control board when the display device as described above is incorporated into the device, the flexible wiring board is cracked from both ends at the bent portion due to bending stress. There was a malfunction. When such a crack reaches a conductive pattern passing between the positioning marks, the conductive pattern is cut to cause a conduction failure, resulting in a malfunction of the display panel.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a display device that does not cause cracks even when a flexible wiring board that connects a display panel and a control board is bent.

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. And a flexible wiring board that can be flexibly connected,
Positioning marks are respectively arranged on both ends of the flexible wiring board, and a plurality of conductive patterns for connecting the display panel and the control board are arranged between the positioning marks, and the vicinity of the positioning marks A display device is provided, wherein a reinforcing dummy conductive pattern extending toward the control board is disposed between the outside of the conductive pattern and both side edges of the flexible wiring board.

  It is preferable that a plurality of the dummy conductive patterns are arranged on both side ends of the flexible wiring board, and the arrangement pitch of the plurality of dummy conductive patterns on the both side ends is the same as the arrangement pitch of the conductive patterns. The conductive pattern and the dummy conductive pattern may be formed in the same formation process. The flexible wiring board may be bent on the control board side with respect to the positioning mark, and the display panel and the control board may be overlapped. It is preferable that the positioning mark is disposed outside a covering region where the conductive pattern is covered with a resin, and the dummy conductive pattern is disposed from outside the covering region to inside the covering region.

  Conventionally, when a flexible wiring board is bent in order to overlap a liquid crystal display panel and a control board, the positioning mark formed on the outer side (on both side ends) of the conductive pattern is closer to the display panel than the positioning mark. Between the outer side of the conductive pattern forming region and both side edges of the flexible wiring board, a region having only a relatively wide resin film in which a conductive pattern or the like is not formed has been formed. When a region of only a resin film with a relatively wide width is formed on both side edges of the flexible wiring board, both sides of the flexible wiring board are bent when the flexible wiring board is bent to overlap the liquid crystal display panel and the control board. Cracks sometimes occurred from the side end toward the conductive pattern in the region only of the resin film at the end.

  However, according to the display device of the present invention, the dummy conductive pattern is formed between the outside of the conductive pattern forming region and the both ends of the flexible wiring substrate, so that the flexible wiring is formed by the metal thin film forming the dummy conductive pattern. Both side ends of the resin film constituting the substrate are reinforced, and even if the flexible wiring board is bent, cracks are effectively prevented from being generated from both ends of the flexible wiring board. Moreover, such a dummy conductive pattern can be formed in the same process as the conductive pattern that contributes to the electrical connection between the liquid crystal display panel and the control substrate. There is no negative effect such as an increase in cost.

  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. 1A shows a state in which the display surface side of the display panel is turned up, and FIG. 1B shows a state in which the back side of the display panel is turned up. A liquid crystal display device (display device) 10 according to the present embodiment includes a liquid crystal display panel (display panel) 11 that displays an image, a control board 12 on which electronic components that control the display panel are mounted, and a liquid crystal display panel. 11 and a flexible flexible wiring board 13 that electrically connects the control board 12 and the control board 12.

  The liquid crystal display panel 11 has a known layer structure such as a liquid crystal layer and an electrode layer, and displays a predetermined image in accordance with a control signal output from the control board 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 flexible wiring board 13 is formed by forming a large number of conductive patterns 22 made of a conductive thin film such as copper on a flexible resin film 21 that can be bent, and can be bent freely according to an embedded device. Then, positioning marks 23 a and 23 b for positioning are formed on both side ends of the flexible wiring board 13 in the width direction. Further, as shown in FIG. 1 b, the flexible wiring board 13 is connected to the covering region where the covering resin 20 is formed so as to cover the conductive pattern 22 and the conductive pattern 22 for connecting to the liquid crystal display panel 11. Outside the covered region where the terminals are formed. That is, the flexible wiring board 13 has a two-layer structure of connection terminals that are continuous from the resin film 21 and the conductive pattern 22 (outside the coating area), a three-layer structure of the resin film 21, the conductive pattern 22, and the coating resin. Area (covering area). The positioning marks 23a and 23b are formed outside the covering region.

  When the liquid crystal display device 10 is manufactured, the liquid crystal display panel 11 is connected to the flexible wiring board 13 in a state where the flexible wiring board 13 is integrated with the control board 12. In this connection, the positioning marks 23a and 23b formed on the flexible wiring board 13 and the panel positioning marks (not shown) on the liquid crystal display panel 11 side are aligned, and the flexible wiring board 13 and the liquid crystal display panel 11 are connected. To fix.

  FIG. 2 is an enlarged plan view of the vicinity of the positioning marks 23 a and 23 b of the flexible wiring board 13. A large number of conductive patterns 22 are formed between the positioning marks 23a and 23b on the flexible wiring board 13 (see FIG. 1b). And in the space | interval A from the outer side of this conductive pattern 22 to the both sides of the resin film 21, the several dummy conductive pattern 25 extended in fixed length toward the control board 12 from the positioning marks 23a and 23b vicinity is formed. Yes. The plurality of dummy conductive patterns 25 are preferably formed from the outside of the covering area where the covering resin is not formed to the covering area.

  The dummy conductive pattern 25 is made of a conductive thin film such as copper, for example, and is formed in the same process as the process of forming the conductive pattern 22 on the resin film 21 when the flexible wiring substrate 13 is manufactured. However, unlike the conductive pattern 22, the dummy conductive pattern 25 does not contribute to signal communication between the control board 12 and the liquid crystal display panel 11, and a pattern in which no current flows, for example, the conductive pattern 22 and the like. Are formed in a form that is not electrically connected.

  For example, the dummy conductive pattern 25 is formed by forming one or several dummy conductive patterns having a wide width in addition to the pattern extending in a narrow width from the vicinity of the positioning marks 23a and 23b toward the control board 12 as illustrated. Various patterns such as extending obliquely with respect to the extending direction of the flexible wiring board 13 can be adopted, and the distance from the outside of the conductive pattern 22 to both sides of the resin film 21 constituting the flexible wiring board 13 However, any shape may be used as long as the pattern extends from the vicinity of the positioning marks 23a and 23b. The arrangement pitch of the plurality of dummy conductive patterns 25 is preferably formed to be the same as the arrangement pitch of the conductive patterns 22, and the width dimension of the dummy conductive patterns 25 is preferably the same as the width dimension of the conductive patterns 22. . With such a configuration, the bending stress of the conductive pattern portion and the bending stress of the dummy conductive pattern portion are not changed, and the force applied to both ends of the flexible wiring board can be reduced.

  Next, the operation of the dummy conductive pattern in the display device of the present invention as described above will be described. When the liquid crystal display device (display device) 10 is incorporated in a portable electronic device or the like, a control substrate 12 is superimposed on the back side of the liquid crystal display panel 11 as shown in FIG. At this time, the flexible wiring board 13 is bent around the line L shown in FIG. 2 (see FIG. 3).

  In the conventional display device, when the flexible wiring board is bent in order to overlap the liquid crystal display panel and the control board in this way, the positioning mark formed on the outer side (on both side ends) of the conductive pattern is more than the positioning mark. However, an area of only a relatively wide resin film in which a conductive pattern or the like is not formed is formed between the outer side of the conductive pattern forming area and both ends of the flexible wiring board near the display panel. When a region of only a resin film with a relatively wide width is formed on both side edges of the flexible wiring board, both sides of the flexible wiring board are bent when the flexible wiring board is bent to overlap the liquid crystal display panel and the control board. Cracks sometimes occurred from the side end toward the conductive pattern in the region only of the resin film at the end.

  However, as in the present invention, the dummy conductive pattern 25 is formed between the outside of the region where the conductive pattern 22 is formed and both ends of the flexible wiring board 13 (see the region indicated by the arrow A in FIG. 2). Both side ends of the resin film 21 are reinforced by the metal thin film forming the dummy conductive pattern 25, and even if the flexible wiring board 13 is bent, cracks are effectively prevented from being generated from both side ends of the flexible wiring board 13. Moreover, since the dummy conductive pattern 25 can be formed in the same process at the same time as the formation of the conductive pattern 22 that contributes to the electrical connection between the liquid crystal display panel 11 and the control substrate 12, productivity due to the generation of a new process is achieved. There is no negative effect such as a decrease in manufacturing cost and an increase in manufacturing cost. In particular, since the dummy conductive pattern 25 is arranged from the outside of the covering region of the two-layer structure to the covering region of the three-layer structure, the flexible wiring board 13 is likely to occur outside the covering region having the two-layer structure. Cracks can be effectively prevented. Further, by making the dummy conductive patterns 25 formed on both side ends the same as the arrangement pitch of the conductive patterns 22, the bending degree can be leveled and the bending stress applied to both side ends can be alleviated. It is possible to prevent cracks generated at both ends of the substrate 13.

  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 such as an organic EL panel. In addition, the dummy conductive pattern may be formed in a range branched from a part of the conductive pattern and having no influence on the circuit configuration.

It is an external appearance perspective view which shows an example of the display apparatus of this invention. It is an enlarged plan view which shows the positioning mark vicinity of a flexible wiring board. It is an external appearance perspective view which shows the apparatus incorporation state of the display apparatus of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Liquid crystal display device (display apparatus), 11 ... Liquid crystal display panel (display panel), 12 ... Control board, 13 ... Flexible wiring board, 22 ... Conductive pattern, 23a, 23b ... Positioning mark, 25 ... Dummy conductive pattern

Claims (5)

A display comprising a display panel for displaying an image, a control board on which electronic components for controlling the display panel are placed, and a flexible wiring board that can be flexibly connected to the display panel and the control board. A device,
Positioning marks are respectively arranged on both ends of the flexible wiring board, and a plurality of conductive patterns for connecting the display panel and the control board are arranged between the positioning marks, and the vicinity of the positioning marks A display device, wherein a reinforcing dummy conductive pattern extending toward a control board is disposed between the outside of the conductive pattern and both side edges of the flexible wiring board. A plurality of the dummy conductive patterns are arranged on both side ends of the flexible wiring board,
The display device according to claim 1, wherein an arrangement pitch of the plurality of dummy conductive patterns on the both side ends is the same as an arrangement pitch of the conductive patterns.   The display device according to claim 1, wherein the conductive pattern and the dummy conductive pattern are formed in the same formation process.   4. The display according to claim 1, wherein the flexible wiring board is bent on the control board side with respect to the positioning mark, and the display panel and the control board are overlapped with each other. 5. apparatus. 5. The positioning mark according to claim 1, wherein the positioning mark is disposed outside a covering region where the conductive pattern is covered with a resin, and the dummy conductive pattern is disposed from outside the covering region to inside the covering region. The display device according to any one of the above.

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