Hitachi Displays, Ltd.

Panasonic Liquid Crystal Display Co., Ltd.

Japan Display Inc.

Hitachi Display Devices, Ltd.

Hiroshi Nakamoto

Akiyoshi Tobe

Ken Kagabu

Yoshikazu Tanabe

Yoshiaki Takahashi

Masafumi Okada

Ken Sugiyama

Masahiro Ito

Koji Hiramoto

Mitsuhiro Sugiyama

Masayuki Mifune

Ken Saito

Toshitsugu Miyawaki

Michihide Shibata

Hidehiro Hanada

Shigeo Shimano

Hiroyuki Yoshida

Hirokazu Yabe

Kazuteru Furuichi

Masamitsu Miyata

Kouji Fujisawa

Display device is provided and includes display panel; and illumination device provided on rear surface side of display panel, wherein illumination device includes light sources, and light guiding member arranged at rear surface side of display panel, light guiding member has holes which penetrates the light guiding member, light sources are housed in corresponding hole, rear surface of light guiding member has first inclined surface inclined upwardly from light source housed in one of holes, front surface side of light guiding member has second inclined surface inclined upwardly from light source housed in one of the holes, and angle of first inclined surface to center line of one of holes is greater than angle of second inclined surface to center line.

Display device, illumination device, and light guiding member

According to an aspect, a display device includes: a display panel configured to transmit light; and an illumination device provided on a rear surface side of the display panel. The illumination device includes a plurality of light sources configured to emit light, and a light guiding member that has translucency and is arranged between the light sources on the rear surface side of the display panel. The light guiding member has a plurality of holes each of which opens in a first direction intersecting with a rear surface of the display panel and in each of which a corresponding one of the light sources is disposed, and a light guiding portion surrounding the holes. A rear surface of the light guiding portion is provided with a first inclined surface inclined with respect to the first direction and a plane orthogonal to the first direction.

A back light unit includes a light guide plate having at least one light introducing portion and a light exit portion, the front surface of the light exit portion being a light exit surface, and a light source facing the light guide plate and emitting light in a light emitting direction. The at least one light introducing portion includes a first portion and a second portion which is connected to the light exit portion, and in which the second portion spreads wider than the first portion in plan view.

Liquid crystal display device

Provided is a liquid crystal display device includes an optical switching member; a light guide plate made of a thermoplastic material, which includes at least one light introducing portion on at least one side surface thereof; and a light source disposed on the at least one side surface, in which: the at least one light introducing portion includes, in plan view of the light guide plate: a first portion extending from a light incident surface, which is an end surface of the at least one light introducing portion, while keeping a substantially constant width; and a second portion, which extends from the first portion and has a form which widens; and at least the second portion is connected to a front surface of the light guide plate through an inclined surface which is smoothly continuous with the front surface of the light guide plate.

In a method of forming a thin light guide plate which includes a compression step in an injection molding step, an optical pattern is liable to be adhered to a mold. Further, in removing the light guide plate from the mold using an ejector pin, a stress is concentrated on a local area of the light guide plate thus generating warping, deformation or irregularities in size of the light guide plate. To overcome such drawbacks, a liquid crystal display device is configured such that an optical pattern portion is compressed, and the light guide plate is removed by making use of a peripheral portion of a mold thus preventing the generation of stress in a local area of the light guide plate due to an ejector pin.

In a backlight which arranges light emitting diodes on a side surface of a light guide plate, even when the light guide plate is made thin by further reducing a thickness of the light guide plate and the light emitting diodes having a thickness larger than the thickness of the light guide plate are used, it is possible to manufacture the light guide plate with high accuracy in a short time. In a liquid crystal display device having a backlight which radiates light to a liquid crystal panel, LEDs are mounted on the light guide plate formed on the backlight as a light emitting element, a light radiation portion of the light guide plate is formed by molding by applying pressure and heat to a sheet-shaped resin, and a light incident portion of the light guide plate is formed by injection molding.

Liquid crystal display device comprising a light guide plate with a light radiation portion and a light incident portion joined by a joint surface and having an inclined surface and projecting portions

Provided is a liquid crystal display device including: an optical switching member; a light guide panel; and a light source, the light guide panel including, on at least one of a front surface and a back surface thereof, a plurality of surface structures including: a first raised surface extending outward being formed as a free surface; a first light reflection surface entering inside from the first raised surface; a second light reflection surface extending outside from the first light reflection surface; and a second raised surface which continues from the second light reflection surface and is formed as a free surface, whereby a liquid crystal display device may be obtained, which includes a thin light guide panel with a thickness of, for example, 1 mm or less.

In a backlight which arranges light emitting diodes on a side surface of a light guide plate, irregularities of radiation light from the backlight can be decreased. In a liquid crystal display device having a backlight which radiates light to a liquid crystal panel, LEDs which constitute a light emitting element are mounted on a light guide plate formed on the backlight, and teardrop-shaped lenses are formed on a light radiation surface of the light guide plate. By changing the advancing directions of lights radiated from the light emitting element using the teardrop-shaped lenses, it is possible to decrease irregularities of a planar light source by scattering the radiation lights from the light guide plate.

A light guiding plate is manufactured with high precision and in a short period of time in a backlight where light emitting diodes are provided on the side of the light guiding plate, even in the case where the light guiding plate is formed so as to have a spherical surface. In a liquid crystal display device having a backlight for illuminating a liquid crystal panel with light, LED's are provided in a light guiding plate in the backlight as a light emitting element, the light emitting portion of the light guiding plate is formed so as to have a spherical surface by applying heat and pressure to a resin in sheet form, and the light guiding plate is manufactured by fusing a light entering portion formed of a resin through injection molding with the light emitting portion.

The present invention provides a backlight of a liquid crystal display device having an inclination surface on a light guide plate and preventing a breakage of a liquid crystal panel, wherein light which leaks from the inclination surface is made to return to the light guide plate and the adhesiveness of the light guide plate and a flexible printed circuit board is increased. In a liquid crystal display device having a backlight which radiates light to a liquid crystal panel, LEDs are formed on a light guide plate formed on the backlight as light emitting elements. Between the plurality of light emitting elements, a projecting portion of the light guide plate is formed, and a reflection member is formed on an adhesive sheet which adheres a projection member and a flexible printed circuit board to each other. By arranging the reflective member and the cushion member close to an inclination surface, light from the inclination surface is made to return to a light guide plate side, and an external force from the outside can be alleviated by a cushion member.

A liquid crystal display device includes a liquid crystal panel and an illumination device. The illumination device has a light guide plate and at least one spot light source on at least one side surface of the light guide plate. The light guide plate includes a large number of upper-surface arcuate cross-sectional grooves in a direction orthogonal to the one side surface on a surface thereof which faces the liquid crystal panel, and a large number of light-incident-surface arcuate cross-sectional grooves are formed in a thickness direction of the light guide plate on at least a portion of the one side surface which faces a position at which the spot light source is arranged. A relationship is provided between a contact angle Oa of the upper-surface arcuate cross-sectional grooves and a contact angle Ea of the light-incident-surface arcuate cross-sectional grooves.

Growing community of inventors

Chiba, Japan

Hiroshi Nakamoto