Liquid crystal display device viewable from both surfaces and portable apparatus using same

Abstract

In front of a liquid crystal display element (1), a surface light source (25) is arranged which emits a light toward the liquid crystal display element (1) and lets lights coming from its front and its back permeate therethrough. The liquid crystal display element (1) has reflection / permeation means (10) which is provided behind a liquid crystal cell (2) and a liquid crystal layer (5), and which reflects a part of a light that comes to each of a plurality of pixels (80) from the front of the liquid crystal cell (2), and lets the other part of the light permeate the reflection / permeation means (10).

Description

TECHNICAL FIELD [0001] The present invention relates to a both surface display type liquid crystal display device and a portable apparatus having a both surface display function. BACKGROUND ART [0002] As disclosed in Unexamined Japanese Patent Application KOKAI Publication No. H10-90678 and Unexamined Japanese Patent Application KOKAI Publication No. 2001-290445, a liquid crystal display device in which two liquid crystal display elements are disposed back to back with their display surfaces facing the opposite directions from each other, and a surface light source for emitting a light toward both the liquid crystal display elements is disposed between them, is known as a both surface display type liquid crystal display device to be used in a portable apparatus such as a portable phone, which has a display function on both surfaces of its case. [0003] However, using two liquid crystal display elements as described above costs high, and both surface display with the use of one liquid...

AI Technical Summary

Benefits of technology

[0006] It is an object of the present invention to provide a liquid crystal display device which is capable of both surface display using one liquid crystal display element, capable of reducing its occupation area, and capable of displaying an image to be viewed from one surface and an image to be viewed from the other surface in a display manner using a light from a surface light source and in a display manner using an external light existing in the external environment.

[0007] It is another object of the present invention to provide a liquid crystal display device which is capable of being miniaturized as a portable apparatus having a both surface display function, capable of displaying images to be viewed from the respective surfaces in a sufficiently large screen size, and capable of displaying images to be viewed form the respective surfaces in a display manner using a light from a surface light source of the liquid crystal display device and in a display manner using an external light.

[0018] Accordingly, with this liquid crystal display device, it is possible to perform both surface display with the use of only one liquid crystal display element, and to make the occupation area of the liquid crystal display device smaller.

[0020] As described above, according to this liquid crystal display device of the present invention, both surface display can be achieved with the use of one liquid crystal display element, the occupation area can be reduced, and both of an image to be viewed from one surface (front surface) and an image to be viewed from the other surface (back surface) can be displayed in a display manner using a light from the surface light source and in a display manner using an external light which is a light in the external environment.

[0050] This portable apparatus of the present invention can be miniaturized by providing display windows to two opposing external surfaces of the portable apparatus respectively, and mounting the liquid crystal display device of the present invention inside the portable apparatus such that the front surface of the liquid crystal display device faces the display window on one of the two external surfaces and the back surface of the liquid crystal display device faces the display window on the other of the two external surfaces. Further, this portable apparatus can display both images to be viewed from the front and the back in a sufficiently large screen size, and can display images on both surfaces in a display manner using a light from the surface light source of the liquid crystal display device and in a display manner using an external light.

Problems solved by technology

However, using two liquid crystal display elements as described above costs high, and both surface display with the use of one liquid crystal display element is desired.

Accordingly, this liquid crystal display device can not be used in a portable apparatus such as a portable phone, in which the mount space for a liquid crystal display device is limited.

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