JP4431348B2 - Liquid crystal display - Google Patents

Description

  The present invention relates to a liquid crystal display device that performs display on both front and back sides suitable for realizing miniaturization.

  2. Description of the Related Art Conventionally, a liquid crystal display device that is small, lightweight, and requires less installation space is known as a type of display device that displays information. A liquid crystal is interposed between a pair of substrates as a display unit of such a liquid crystal display device. An encapsulated liquid crystal display panel is used.

  As a liquid crystal display panel in recent years, a connection terminal is formed in a terminal forming portion of a substrate, and an anisotropic conductive material is used for a bump of a liquid crystal driving semiconductor element such as a liquid crystal driving LSI or a liquid crystal driving IC. COG (chip on glass) mounting method that can be directly connected can easily reduce the number of members and man-hours required for the package of the semiconductor element for driving the liquid crystal, make the terminal pitch finer, and simplify the structure. (For example, refer to Patent Document 1).

  In recent years, a liquid crystal display device capable of performing individual display on both the front and back sides by two liquid crystal display panels has been used as a display device for a small portable terminal such as a foldable mobile phone ( For example, Patent Document 2).

  A conventional liquid crystal display device capable of performing display on both the front and back surfaces will be described by exemplifying a liquid crystal display device used for a folding mobile phone.

  FIG. 3 is a schematic cross-sectional view of a conventional liquid crystal display device that performs display on both front and back surfaces, and FIG. 4 is a schematic plan view of a sub-panel.

  As shown in FIG. 3, for example, a conventional liquid crystal display device 1 has two liquid crystal display panels 2 for performing individual display on both the front and back sides. These two liquid crystal display panels 2 are formed in a substantially rectangular shape having a long side in the left-right direction in FIG. 3, and are arranged with a light guide plate 3 constituting a part of a common illumination device interposed therebetween. . Of the two liquid crystal display panels 2, the liquid crystal display panel shown in the upper part of FIG. 3 is a large main panel 2M used for displaying main information. The liquid crystal display panel shown in the lower part of FIG. The sub-panel 2S has a small size used for displaying schematic or auxiliary information. The image display area 4M of the main panel 2M is formed larger than the image display area 4S of the sub panel 2S, and the outer dimensions of the main panel 2M are larger than the outer dimensions of the sub panel 2S. The length dimension 5M along the long side shown in the left-right direction is larger than the length dimension 5S along the long side of the sub-panel 2S. Further, the two liquid crystal display panels 2 are arranged so that their left end surfaces are substantially flush with each other.

  At least the right side of the substrate 2Ma shown in the upper part of FIG. 3 of the main panel 2M protrudes outside the substrate 2Mb shown in the lower part of FIG. 3, that is, outside the image display area 4M, as exaggerated in FIG. A terminal forming portion 6M is formed. A liquid crystal driving semiconductor element 7, more specifically, a liquid crystal driving semiconductor element 7M for a main panel is mounted on the terminal forming portion 6M. Further, one end of a flexible wiring board 8 used for supplying power, signals, and the like, specifically, a flexible wiring board 8M for a main panel, is connected to the board edge side of the terminal forming portion 6M.

  At least on the right side of the substrate 2Sa shown in the lower part of FIG. 3 of the sub-panel 2S, as exaggerated in FIGS. 3 and 4, to the outside of the substrate 2Sb shown in the upper part of FIG. 3, that is, outside the image display region 4S. A projecting terminal forming portion 6S is formed. A liquid crystal driving semiconductor element 7, more specifically, a sub panel liquid crystal driving semiconductor element 7S is mounted on the terminal forming portion 6S. In addition, one end of a flexible wiring board 8 used for supplying power, signals, and the like, specifically, a flexible wiring board 8S for a sub panel, is connected to the substrate edge side of the terminal forming portion 6S.

  Note that the terminal forming portions 6 (reference numeral 6 is a generic name for the terminal forming portion 6M and the terminal forming portion 6S) of both the liquid crystal display panels 2 are both external connection terminals used for connection to the flexible wiring board 8, and liquid crystal driving. A large number of terminals such as an input terminal and an output terminal used for connection to the bumps of the semiconductor element 7 are formed, and an external connection terminal and an input terminal are provided on the frame portion of the liquid crystal display panel including the terminal formation portion 6. Predetermined patterns such as input-side routing wirings to be connected and output-side routing wirings to connect the output terminals and the display electrodes are formed.

JP 2002-196703 A JP 2001-067049 A

  By the way, in the conventional liquid crystal display device 1 described above, since the liquid crystal driving semiconductor element 7 is mounted on each of the terminal forming portions 6 of the two liquid crystal display panels 2, the recent narrowing of the frame. In the case of a liquid crystal display device used as a display unit of a small portable terminal such as a cellular phone in recent years, for example, a liquid crystal display panel is required to be narrowed and miniaturized in units of 0.5 mm or 1 mm. There was a problem that we could not respond.

  That is, in the conventional liquid crystal display device 1, the liquid crystal driving semiconductor element 7 is mounted on each of the terminal forming portions 6 of the two liquid crystal display panels 2. It is necessary to provide a mounting area for the semiconductor element 7 for use, and the length dimension of the terminal forming portion 6 shown in the left-right direction in FIG. 3 is increased by about 3 mm, for example, by the mounting area of the semiconductor element 7 for liquid crystal driving. was there. As a result, the length 5M of the main panel 2M is increased by an amount corresponding to the mounting area of the liquid crystal driving semiconductor element 7, which hinders narrowing of the frame and downsizing.

  The present invention has been made in view of this point, and an object of the present invention is to provide a liquid crystal display device that can be easily narrowed and reduced in size.

In order to achieve the above-described object, the liquid crystal display device according to claim 1 of the present invention is characterized in that in the liquid crystal display device in which individual display is performed on both the front and back surfaces by two liquid crystal display panels, A liquid crystal driving semiconductor element for driving the one liquid crystal display panel, wherein an image display area in one of the two liquid crystal display panels is formed larger than an image display area in the other liquid crystal display panel and a liquid crystal driving semiconductor element for driving the other liquid crystal display panel is in that it is both mounted on the terminal formation portion of the other of the liquid crystal display panel. By adopting such a configuration, it is not necessary to provide a mounting region for mounting a liquid crystal driving semiconductor element in the terminal forming portion of the liquid crystal display panel having a large outer size among the two liquid crystal display panels. .

  According to the liquid crystal display device of the present invention according to claim 1, since it is not necessary to provide a mounting region for mounting a liquid crystal driving semiconductor element in a terminal forming portion of a liquid crystal display panel having a large outer size, There are extremely excellent effects such as easy downsizing.

  The present invention will be described below with reference to embodiments shown in the drawings.

  1 and 2 show the main part of an embodiment of a liquid crystal display device according to the present invention. FIG. 1 is a schematic sectional view, and FIG. 2 is a schematic plan view of a sub-panel.

  The liquid crystal display device according to the present embodiment is exemplified for a foldable mobile phone.

  As shown in FIG. 1, the liquid crystal display device 11 of this embodiment has two liquid crystal display panels 12 for performing individual display on both the front and back sides. These two liquid crystal display panels 12 are formed in a substantially rectangular shape having a long side in the left-right direction in FIG. 3, and are arranged with a light guide plate 13 constituting a part of the shared lighting device interposed therebetween. . The liquid crystal display panel shown in the upper part of FIG. 1 of the two liquid crystal display panels 12 is a large main panel 12M used for displaying main information. The liquid crystal display panel shown in the lower part of FIG. The sub-panel 12S has a small size used for displaying schematic or auxiliary information. The image display area 14M of the main panel 12M is formed larger than the image display area 14S of the sub panel 12S, and the outer dimensions of the main panel 12M are larger than the outer dimensions of the sub panel 12S. The length dimension 15M along the long side shown in the left-right direction in FIG. 1 is formed larger than the length dimension 15S along the long side of the sub-panel 12S. Further, the two liquid crystal display panels 12 are arranged so that their left end surfaces are substantially flush with each other.

  As shown in an exaggerated manner in FIG. 1, at least the right side of the substrate 12Ma shown in the upper part of FIG. 1 of the main panel 12M projects to the outside of the substrate 12Mb shown in the lower part of FIG. 1, that is, outside the image display area 14M. A terminal forming portion 16M is formed. One end of a flexible wiring board 18 that electrically connects the main panel 12M and the sub panel 12S is connected to the terminal edge side of the terminal forming portion 16M in order to receive power and signals from the sub panel 12S. Yes. The terminal forming portion 16M of the main panel 12M is formed with external connection terminals used for connection to the flexible wiring board 18. The frame portion including the terminal forming portion 16M has external connection terminals and display electrodes. A predetermined pattern such as a lead wiring that connects the two is formed.

  At least on the right side of the substrate 12Sa shown in the lower part of FIG. 1 of the sub-panel 12S, as shown exaggeratedly in FIGS. 1 and 2, to the outside of the substrate 12Sb shown in the upper part of FIG. An overhanging terminal forming portion 16S is formed. The terminal forming portion 16S includes two liquid crystal driving semiconductor elements 17, more specifically, a liquid crystal driving semiconductor element 17M for a main panel and a liquid crystal driving semiconductor element for a sub panel. 17S is implemented. Further, the other end of the flexible wiring board 18 is connected to the board edge side of the terminal forming portion 16S. Further, as shown in FIG. 2, one end of a flexible wiring board 19 for supplying power and signals to both of the two liquid crystal display panels 12 is connected to one end edge side of the terminal forming portion 16S. Yes. The terminal forming portion 16S of the sub-panel 12S is used for connecting two sets of external connection terminals used for connection to the two flexible wiring boards 18 and 19 and two bumps of the liquid crystal driving semiconductor element 17 respectively. A large number of terminals such as two sets of input terminals and output terminals are formed. On the frame portion of the liquid crystal display panel including the terminal forming portion 16S, an input side lead wiring for connecting the external connection terminal and the input terminal, an output A predetermined pattern such as an output-side routing wiring that connects the terminal and the display electrode is formed.

  Since other configurations are the same as those of a conventionally known liquid crystal display device, detailed description and illustration thereof will be omitted.

  In addition, it is good also as a structure which provides an illuminating device separately in each of the two liquid crystal display panels 12, and it is good also as a structure which does not provide the light-guide plate 13 between the two liquid crystal display panels 12. FIG.

  Next, the operation of the present embodiment having the above-described configuration will be described.

  According to the liquid crystal display device 11 of the present embodiment, the liquid crystal driving semiconductor element 17M for the main panel is mounted on the terminal forming portion 16S of the sub panel 12S. There is no need to provide a mounting area for mounting the semiconductor element 17. As a result, without changing the size of the image display area 14M of the main panel 12M, the length dimension shown in the horizontal direction in FIG. 1 of the terminal forming portion 16M of the main panel 12M is changed to the terminal forming portion 6M of the conventional main panel 2M. Compared to the configuration in which the liquid crystal driving semiconductor element 7 is mounted, it can be easily and reliably shortened by at least the amount necessary for mounting the liquid crystal driving semiconductor element 7. For example, while the length dimension of the conventional terminal forming portion 6M is about 5 mm, the length dimension of the terminal forming portion 16M of the present embodiment can be reduced to about 1.2 mm.

  That is, according to the liquid crystal display device 11 of the present embodiment, the length dimension 15M along the long side of the main panel 12M can be made shorter than before.

  Therefore, according to the liquid crystal display device 11 of the present embodiment, it is not necessary to provide a mounting region for mounting the liquid crystal driving semiconductor element 17 in the terminal forming portion 16M of the main panel 12M which is a large liquid crystal display panel. Therefore, it is possible to easily achieve a narrow frame and a small size.

  In addition, this invention is not limited to embodiment mentioned above, A various change is possible as needed.

  For example, the size of the sub panel may be smaller than that of the main panel, and may be approximately the same size.

  Further, the liquid crystal driving semiconductor element for driving the main panel may be mounted in any position as long as it is a terminal forming portion of the sub panel, and in parallel with each liquid crystal driving semiconductor element in a direction perpendicular to the protruding direction of the terminal forming portion. It may be installed.

Typical sectional drawing which shows the principal part of embodiment of the liquid crystal display device which concerns on this invention Schematic plan view showing the main part of the sub-panel of FIG. Typical sectional drawing which shows the principal part of the conventional liquid crystal display device Schematic plan view showing the main part of the sub-panel of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Liquid crystal display device 12 Liquid crystal display panel 12M Main panel 12S Sub panel 12Ma, 12Mb, 12Sa, 12Sb Substrate 14M, 14S Image display area 15M, 15S Length dimension 16, 16M, 16S Terminal formation part 17, 17M, 17S Liquid crystal drive semiconductor element

Claims (1)

In a liquid crystal display device which performs individual display on both the front and back surfaces by two liquid crystal display panels,
The image display area in one liquid crystal display panel of the two liquid crystal display panels is formed larger than the image display area in the other liquid crystal display panel,
The liquid crystal driving semiconductor element for driving the one liquid crystal display panel and the liquid crystal driving semiconductor element for driving the other liquid crystal display panel are both mounted on the terminal forming portion of the other liquid crystal display panel. A characteristic liquid crystal display device.