Hitachi Displays, Ltd.

Japan Display Inc.

Panasonic Liquid Crystal Display Co., Ltd.

Hitachi Display Devices, Ltd.

Hitachi Displays Devices, Ltd.

Saburo Watanabe

Hiroshi Tokuyama

Norihisa Fukayama

Yoshio Toriyama

Seiichi Nishiyama

Akio Tezuka

Liquid crystal display device preventing brightness reduction of a backlight even when a recess is formed in a lower frame accommodating the backlight and a light-emitting diode substrate mounted with a light-emitting diode is accommodated in the recess. A backlight includes a reflection member arranged on the back side of a light guide plate, and the light-emitting diode irradiating the light guide plate with illumination light from a side portion of the light guide plate. The recess protruding on the back side is formed in the lower frame for accommodating and arranging the light-emitting diode substrate mounted with the light-emitting diode therein. A part of an end portion of the reflection member protrudes into a space formed by the recess toward the light emitting diode. A holding member is arranged between the reflection member and the lower frame at least to hold the protruding region of the reflection member.

Liquid crystal display device

Provided is a display device, including: a first protrusion formed to an inner side surface of one of side walls of the frame on a short side of an angled corner portion surrounded by the side walls; a second protrusion formed to an inner side surface of one of the side walls on a long side of the angled corner portion; and a third protrusion formed at another angled corner portion on another end side of at least one of the side walls sharing the angled corner portion provided with the first and second protrusions, and formed to an inner side surface of one of the side walls that is opposed to the side wall to which the first protrusion and/or the second protrusion are/is arranged, the optical sheet including cut-out first to third recesses which are to be fitted to the first to third protrusions.

Display device

In a liquid crystal display device which uses light emitting diodes as a light source, the present invention provides a light source which can be effectively housed in a housing casing of a backlight even when an area of a printed circuit board is increased by taking radiation of heat from the light emitting diodes into consideration. A printed circuit board is formed by arranging light emitting diodes on a flexible substrate. The printed circuit board is formed with an area larger than an area of a light incident surface of a light guide plate, and is arranged to face the light incident surface of the light guide plate in an opposed manner. The light guide plate and the printed circuit board are housed in the inside of a housing casing, the printed circuit board is made foldable by forming slits in the printed circuit board thus enabling housing of the printed circuit board in the housing casing in a folded shape. Due to housing of the printed circuit board in a folded shape, a contact area of the printed circuit board with the housing casing is increased thus enhancing a heat radiation effect.

Plural light-emitting diodes are disposed in an on-line arrangement on a surface a circuit board facing an optical guide and spacers having a projecting dimension larger than the projecting dimension of this light-emitting diode from the surface are disposed adjacent to the light-emitting diode on the surface of the circuit board.

Liquid crystal display device having spacers disposed between an edge lit optical guide and light-emitting elements

There is provided a light source, which can efficiently be housed even if the area of the substrate increases while giving extra consideration to the heat radiation of the light emitting diodes in a liquid crystal display device using the light emitting diodes as a light source. A plate-like light source section is formed by arranging the light emitting diodes on a metal substrate. The plate-like light source section is formed to have a larger area than an entrance surface of a light guide plate, and is disposed so as to face the entrance surface of the light guide plate. The light guide plate and the plate-like light source section are housed in a housing case, and the housing case is formed to have a larger depth in a part for housing the plate-like light source section than in a part for housing the light guide plate. A cushion member is provided between the light guide plate and the housing case to prevent the light guide plate from being moved by vibrations.

An object of the present invention is to improve the color reproduction capability of a liquid crystal display backlight using white LEDs. A backlight of the present invention includes: a light guide plate; a light diffusing optical waveguidedisposed adjacent the light guide plate; a plurality of white LEDsdisposed on the light diffusing optical waveguide; and single color LEDs (red LEDs)disposed on respective opposite sides of the light diffusing optical waveguide; wherein light from the white LEDspasses through the light diffusing optical waveguideand enters the light guide platethrough a side thereof, whereas light from the single color LEDsis diffused by the light diffusing optical waveguidebefore entering the light guide platethrough the same side thereof. Thus, the light diffusing optical waveguidemixes light from the white LEDsand single color LEDs, resulting in improved color reproduction capability of the backlight.

LED backlight and liquid crystal display device using thereof

In a liquid crystal display device which uses light emitting diodes as a light source, a backlight can efficiently house a heat radiation plate even when an area of the heat radiation plate is increased by taking the radiation of heat from the light emitting diodes into consideration. Light emitting diodes are arranged on a metal substrate to form a plate-shaped light source portion. A heat radiation effect is enhanced by adhering a heat radiation plate to the plate-shaped light source portion. The heat radiation plate to which the plate-shaped light source is adhered is constituted as a housing casing thus efficiently housing the heat radiation plate. A problem which occurs due to the use of the metal-made housing casing can be overcome by mounting a resin-made light guide plate fixing member on the housing casing.

A planar illumination device is provided that can achieve even distributions of mixed colors and luminance, downsizing and weight saving without lowering the luminous efficiency of LED chips. In addition, a liquid crystal display device using the planar illumination device as a backlight is provided. A polygonal flat plate-like light guide plate GLB is combined with a plurality of LED chips DDDemitting light with different colors from each other to constitute a color mixing unit DUT. A plurality of the color mixing units are arranged on printed circuit boards RFB having a reflection function to constitute a planar illumination device. The planer illumination device is installed on the back of a liquid crystal display panel, thus constituting a liquid crystal display device.

Growing community of inventors

Ichinomiya, Japan

Saburo Watanabe