Sharp Kabushiki Kaisha Corporation

Tsuyoshi Ebi

Takeshi Masuda

Yukihiro Sumida

Yutaka Sawayama

A front-illuminating device of the present invention, which is placed over the entire surface of an object to be illuminated such as a reflection-type liquid crystal display device when it is used, is provided with a light source and a light-directing body. The light-directing body has an incident surface on which light from the light source (light-source light) is made incident, a first light-releasing surface for releasing the light toward the object to be illuminated, and a second light-releasing surface which faces the first light-releasing surface and releases reflected light from the object to be illuminated. The second light-releasing surface is formed into a step shape in which slanting portions and flat portions are alternately placed. The light source light, released from the first light-releasing surface to the object to be illuminated, is reflected by the object to be illuminated and the reflected light is allowed to reach the observer from the first light-releasing surface through the flat portions. In this case, among the light-source light rays, the light components progressing in parallel with the flat portions are reflected by the slanting portions and directed to the object to be illuminated. Consequently, the present invention makes it possible to provide a brighter front-illuminating device in which the efficiency of use of the light-source light is improved.

Front illuminating device and a reflection-type liquid crystal display using such a device

A front light () and a reflecting liquid crystal display of the present invention includes a dot light emitting source (), and a light guiding body () having a light incident surface () to which light from the dot light emitting source () is incident and a light outgoing surface () from which the incident light outgoes, and light from the dot light emitting source () is in a linearly emitting state at least when incident onto the light incident surface (). By so doing, it is possible to provide bright, inexpensive, low-power consuming front light () and reflecting liquid crystal display which do not cause shadows or a moire fringe from the dot light emitting source (), or a light-dark difference in luminance.

Lighting element for liquid crystal display

A liquid crystal display apparatus includes: an illumination section having a light source and an optical guide member, and a reflection type LCD having a display region including a plurality of pixels for performing a display function, the optical guide member having first and second principal faces opposite to each other and first and second end faces opposite to each other. The reflection type LCD is disposed on or above the first principal face of the optical guide member. Light from the light source enters the optical guide member at the first end face, exits the optical guide member at the first principal face so as to be incident on the reflection type LCD and reflected therefrom, reenters the optical guide member at the first principal face, and exits the optical guide member at the second principal face toward a viewer.

Liquid crystal display apparatus and electronic device incorporating the same

Featured are a front-illuminating device including a light source and first and second light-directing bodies. The first light-directing body is disposed in front of an object to be illuminated and has a first light-releasing surface from which light is released to the object to be illuminated and a second light-releasing surface, placed face to face with the first light-releasing surface, for releasing light reflected from the object to be illuminated. The second light-releasing surface also is formed into a step shape and includes slanting portions that reflect light mainly from the light source toward the first light-releasing surface. The second light-directing body is disposed between the first light-directing body and the object to be illuminated and is configured and arranged so a distance from each of the slanting portions to the surface of the second light-directing body second surface is essentially uniform.

Front-illuminating device and a reflection-type liquid crystal display using such a device

A reflective type LCD is provided with a front-light. The front light includes an optical film provided on the large face of a lightguide which faces the liquid crystal display device. A two dimensional area defined by the optical film is greater than a two dimensional area defined by a window formed in the protection member, but less than a two dimensional area defined by the lightguide, so that at least a portion of a peripheral edge of the optical film is located between the end face of the window and the end face of the light guide as viewed from a front of the LCD apparatus.

Reflective LCD with front light and protective member with window

Liquid crystal display apparatus and electronic device incorporating the same wherein the optical guide having particular periodic structure

A front light includes a light source, a light guide for receiving light from the light source through an end surface of the light guide and outputting the light through a first large surface which is substantially perpendicular to the end surface, and a polarization selecting section for selectively transmitting light having particular polarization, the polarization selecting section being attached to the first large surface of the light guide such that any reflection does not occur at an interface between the polarization selecting section and the light guide.

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Nara, Japan

Tsuyoshi Ebi