JP2007199464A - Display device and flexible printed wiring board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display device capable of enhancing reliability of connection of a flexible printed wiring board. <P>SOLUTION: In a liquid crystal display device 100 having a liquid crystal display panel 101, a control circuit 105 controlling the liquid crystal display panel 101 and the flexible printed wiring board 103 connecting the liquid crystal display panel 101 to the control circuit 105, the flexible printed wiring board 103 has a notched part 107 provided from an end side thereof and an aperture part 108 of an almost circular shape is provided at a tip of the notched part 107. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a display device and a flexible printed wiring board, and more particularly to a display device having a flexible printed wiring board for connecting a display panel and a control circuit, and a flexible wiring board used therefor.

  In recent years, a display device such as a liquid crystal display device has been used in many electronic devices such as a mobile phone, a portable information terminal, an electronic notebook, a portable TV, and an automobile speed meter because of convenience such as small size and light weight and power saving. In the liquid crystal display device, while the display screen is enlarged, it is desired to make the area other than the display area of the liquid crystal display panel, that is, the frame area as small as possible (narrow frame).

In order to cope with such a narrow frame, a drive circuit for driving a liquid crystal display panel is mounted on a glass substrate constituting the liquid crystal display panel, and control for supplying a power supply voltage and a drive signal to the drive circuit In order to connect circuits, a flexible printed wiring board (hereinafter referred to as FPC (Flexible Printed Circuit)) is mounted on the outer periphery of a liquid crystal display panel (for example, see Patent Document 1). .
Japanese Patent Laid-Open No. 11-024097

  Generally, after connecting the liquid crystal display panel and the FPC with a conductive material such as ACF (Anisotropic Conductive Film), the connection terminal provided on the FPC is directly soldered to the connection terminal on the control circuit side, or control is performed. The FPC and the control circuit are connected by being inserted into the connector on the circuit side.

  However, when the FPC is connected to the liquid crystal display panel in a shifted state, the position of the FPC connection terminal is shifted from the connection terminal position of the control circuit. In this case, if the FPC and the control circuit are forcibly connected, the FCP will be bent or stretched. Due to such bending or stretching of the FPC, a load is applied to the FPC, the FPC is disconnected from the control circuit or the liquid crystal display panel, and a connection failure occurs.

  Further, in the current liquid crystal display device, display contents are increased and the number of wirings is increased. For this reason, the number of connection terminals increases, and the connection terminals naturally have to have a narrow pitch. As described above, when the position of the FPC is slightly shifted, there is a problem that adjacent connection terminals are short-circuited. For this reason, in the manufacturing process of the liquid crystal display device, the positioning of the FPC requires a lot of time, and the working efficiency is poor.

  The present invention has been made in the background as described above, and an object of the present invention is to provide a display device capable of improving the connection reliability of a flexible printed wiring board and a flexible printed wiring board used therefor. Is to provide.

  A display device according to a first aspect of the present invention is a display device including a display panel, a circuit that supplies a signal to the display panel, and a flexible printed wiring board that connects the display panel and the circuit. The flexible printed wiring board has a cut portion provided from a side edge, and a substantially circular opening is provided at the tip of the cut portion. With such a configuration, a highly reliable connection between the display panel and the control circuit using a flexible printed wiring board can be easily performed.

  In the display device according to the second aspect of the present invention, in the display device described above, the size of the opening is larger than the width of the cut portion. Thus, by setting the size of the opening to be larger than the width of the notch in the width direction of the notch, the allowable range of misalignment of the flexible printed wiring board can be further expanded. .

  In the display device according to a third aspect of the present invention, in the above display device, the length of the cut portion from the side end side is not more than half of the width of the flexible printed wiring board. With such a configuration, connection reliability can be improved.

  In the display device according to a fourth aspect of the present invention, in the above display device, at least one of the cut portions is provided on each of opposite side edges of the flexible printed wiring board. Thereby, the tolerance | permissible_range of the position shift of a flexible printed wiring board can further be expanded.

  The flexible printed wiring board concerning the 5th mode of the present invention is a flexible printed wiring board which connects a display panel and a circuit which supplies a signal to the display panel, and the flexible printed wiring board is from a side edge. A cut portion is provided, and a substantially circular opening is provided at the tip of the cut portion. Thereby, the flexible printed wiring board which can perform highly reliable connection with a display panel and a control circuit easily can be provided.

  In the flexible printed wiring board according to the sixth aspect of the present invention, in the flexible printed wiring board described above, the size of the opening is larger than the width of the cut portion. Thereby, the freedom degree of a flexible printed wiring board can be improved.

  A flexible printed wiring board according to a seventh aspect of the present invention is the above-mentioned flexible printed wiring board, wherein the length of the cut portion from the side edge is not more than half of the width of the flexible printed wiring board. It is. Thereby, the reliability of connection can be improved.

  The flexible printed wiring board according to an eighth aspect of the present invention is the above-described flexible printed wiring board, wherein the cut portion is provided at one or more on opposite side edges of the flexible printed wiring board. is there. Thereby, the freedom degree of a flexible printed wiring board can further be improved.

  According to the present invention, it is possible to provide a display device capable of improving the reliability of connection of a flexible printed wiring board and a flexible printed wiring board used therefor.

  Hereinafter, embodiments to which the present invention can be applied will be described. The following description explains the embodiment of the present invention, and the present invention is not limited to the following embodiment.

  An embodiment of the present invention will be described with reference to FIG. FIG. 1 is a diagram showing an example of the configuration of a display device according to the present invention. Here, an STN (Super Twisted Nematic) type simple matrix liquid crystal display device 100 will be described as an example of a display device. As shown in FIG. 1, the liquid crystal display device 100 according to this embodiment includes a liquid crystal display panel 101, a drive circuit 102, an FPC 103, an external connection terminal 104, a control circuit 105, a connector 106, a cut portion 107, and an opening portion 108. Have.

  The liquid crystal display panel 101 displays an image based on the input display signal. The liquid crystal display panel 101 has a configuration in which liquid crystal is sealed between two substrates made of glass or the like. On one substrate, a plurality of signal electrodes are formed at regular intervals in the column direction. On the other substrate, scanning electrodes are formed at regular intervals in the row direction so as to cross the signal electrodes. The intersection between the scanning electrode and the signal electrode corresponds to a pixel. The scanning electrode and the signal electrode are formed of a transparent conductive thin film such as ITO (Indium Tin Oxide). In the liquid crystal display panel 101, the display area is composed of a plurality of pixels.

  The drive circuit 102 is electrically connected to the liquid crystal display panel 101 and outputs various control signals, scanning voltages, display voltages, and the like necessary for image display based on display signals input from the outside. . The drive circuit 102 is mounted on a glass substrate on one side of the liquid crystal display panel 101 by COG (Chip On Glass).

  A backlight unit (not shown) is provided on the back surface of the liquid crystal display panel 101. The backlight unit irradiates the liquid crystal display panel 101 with planar light from the non-viewing side of the liquid crystal display panel 101. As the backlight unit, for example, one having a general configuration including a light source, a light guide plate, a prism sheet, and the like is used.

  The FPC 103 is thermocompression bonded by ACF (Anisotropic Conductive Film) or the like on one side where the drive circuit 102 of the liquid crystal display panel 101 is provided. ACF contains a predetermined amount of conductive particles such as metal particles in an insulating adhesive. A connection terminal (not shown) provided on the FPC 103 and a connection terminal (not shown) on the liquid crystal display panel 101 side are electrically connected by conductive particles contained in the ACF, and the FPC 103 and the liquid crystal display panel 101 are also connected. Is bonded.

  Further, an external connection terminal 104 is provided on a side of the FPC 103 that faces the side connected to the liquid crystal display panel 101. The external connection terminal 104 is inserted into a connector 106 provided in the control circuit 105. Thereby, the control circuit 105 and the liquid crystal display panel 101 are connected via the FPC 103. The wiring of the FPC 103 is provided from the connector 106 side to the connection terminal side of the liquid crystal display panel 101. Further, the wiring of the FPC 103 is formed in a wave shape, for example, so as to bypass a cut portion 107 described later. The liquid crystal display panel 101 can be driven by supplying a power supply voltage and a display signal from the control circuit 105 to the drive circuit 102 through the wiring of the FCP 103.

  A cut portion 107 is provided on the side edge of the FPC 103. The cut portion 107 is formed from the side edge of the FPC 103 toward the center in the width direction. This cut portion 107 can be easily formed by punching a general FPC 103. When the FPC 103 is connected to the liquid crystal display panel 101 in a shifted state, the position of the external connection terminal 104 of the FPC 103 is shifted from the position of the connector 106 of the control circuit 105. Conventionally, in such a case, if the FPC and the control circuit are forcibly connected, the FCP will be bent or stretched. A load is applied to the FPC due to such bending or stretching of the FPC, and the FPC is disconnected from the control circuit or the liquid crystal display panel, resulting in poor connection.

  However, in the present invention, the stress generated by the position shift of the FPC 103 can be absorbed by the cut portion 107. That is, the stress generated in the FPC 103 can be dispersed by the cut portion 107. Therefore, a highly reliable connection between the liquid crystal display panel 101 and the control circuit 105 by the FPC 103 can be easily performed. In addition, even if the external connection terminal 104 of the FPC 103 and the connector 106 are slightly deviated from each other, a highly reliable connection can be performed. Therefore, the positioning of the FPC 103 required for the connection between the FPC 103 and the liquid crystal display panel 101 is possible. Such time can be shortened and work efficiency can be improved.

  Further, even when the number of external connection terminals 104 is increased in the liquid crystal display device 100 and the connection terminals 104 have a narrow pitch, the FPC 103 can be dispersed by the cut portions 107 so that stress due to bending or stretching of the FPC 103 can be dispersed. Will not shift. Thereby, the problem that an adjacent connection terminal will short-circuit can be reduced.

  An opening 108 is provided at the tip of the cut portion 107. The opening 108 can be easily formed by punching the FPC 103, similarly to the formation of the notch 107 described above. Moreover, the shape of the opening part 108 is a substantially circular shape. By adopting such a shape, the movable range of the FPC 103, that is, the degree of freedom increases, and the allowable range of positional deviation of the FPC 103 is expanded. Further, even when a load is applied to the FPC 103 due to the bending or stretching of the FPC 103, the occurrence of a problem that the FPC 103 is cracked from the cut portion 107 and the pattern wiring on the FPC is cut is reduced. it can.

  Further, one or more cut portions 107 are provided on each of two opposing side edges of the FPC 103. In the present embodiment, as shown in FIG. 1, two notches 107 are provided on the left side edge and one on the right side edge. Further, the cut portions 107 formed on the opposite side edges are formed so as to be displaced from each other. As described above, since one or more cut portions 107 are provided on the opposite side edges of the FPC 103, the movable range of the FPC 103 is further expanded, and the allowable range of positional deviation of the FPC 103 is expanded.

  Here, the configuration of the FPC 103 will be described in detail with reference to FIG. FIG. 2 is an enlarged view showing a partial configuration of the FPC 103 according to the present invention. As described above, the FPC 103 is provided with the cut portion 107 and the opening 108.

  As shown in FIG. 2, the size (diameter D) of the opening 108 is larger than the width (d) of the notch 107. Thereby, as shown in FIG. 2, the notch part 107 can open large centering on the opening part 108. As shown in FIG. For this reason, as described above, the movable range of the FPC 103 is expanded, and the allowable range of misalignment of the FPC 103 is expanded. Moreover, it is preferable that the width | variety (d) of the notch part 107 is 1 mm or less. Thereby, the increase in the outer diameter dimension of the FPC 103 can be suppressed, and the cost increase can be reduced.

  In addition, the length (l) from the side edge of the cut portion 107 is preferably less than or equal to half the width (L) of the FPC 103. Thereby, even when the cut portion 107 is connected in a widened or narrowed state, the deviation of the FPC 103 from the liquid crystal display panel 101 can be reduced, and the reliability of the liquid crystal display panel 101 and the control circuit 105 by the FPC 103 can be reduced. High connection can be made easily.

  In this manner, by providing the cut portion 107 and the opening 108 in the FPC 103 connected to the liquid crystal display device 100, a highly reliable connection can be easily performed even when the FPC 103 is displaced.

  The method of the liquid crystal display panel is not limited to the above example. For example, as in the IPS (In Plane Switching) method, an electrode is formed only on one glass substrate, and the glass substrate is opposed to the glass substrate. A method in which a liquid crystal display panel is configured by sandwiching liquid crystal between substrates may be used.

  Moreover, although this invention illustrated and demonstrated the liquid crystal display device as embodiment, it is applicable also to other display apparatuses, such as an organic EL (Electro Luminescence) display apparatus. Needless to say, the present invention can be applied not only to the case where the FPC 103 is connected by the connector 106 but also to the case where the FPC 103 is connected by soldering or the like.

It is a figure which shows the structure of the liquid crystal display device concerning embodiment of this invention. It is a figure which shows the structure of the flexible printed wiring board which concerns on embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Liquid crystal display device 101 Liquid crystal display panel 102 Drive circuit 103 Flexible printed wiring board 104 External connection terminal 105 Control circuit 106 Connector 107 Notch part 108 Opening part

Claims (8)

A display panel;
A circuit for supplying a signal to the display panel;
A flexible printed wiring board for connecting the display panel and the circuit;
A display device comprising:
The flexible printed wiring board has a cut portion provided from a side edge,
A display device in which a substantially circular opening is provided at a tip of the cut portion.   The display device according to claim 1, wherein a size of the opening is larger than a width of the cut portion.   The display device according to claim 1, wherein a length of the cut portion from the side end side is equal to or less than half of a width of the flexible printed wiring board.   4. The display device according to claim 1, wherein at least one of the cut portions is provided on each of opposite side edges of the flexible printed wiring board. A flexible printed wiring board for connecting a display panel and a circuit for supplying a signal to the display panel,
The flexible printed wiring board has a cut portion provided from a side edge,
A flexible printed wiring board in which a substantially circular opening is provided at a tip of the cut portion.   The flexible printed wiring board according to claim 5, wherein a size of the opening is larger than a width of the cut portion.   The flexible printed wiring board according to claim 5 or 6, wherein a length of the cut portion from the side end side is not more than half of a width of the flexible printed wiring board.   8. The flexible printed wiring board according to claim 5, wherein one or more of the cut portions are provided on each of opposite side edges of the flexible printed wiring board.

Images