Backlighting system for a liquid crystal display including an integrally molded light guiding plate and frame with a deformation absorbing means

A backlighting apparatus for a liquid crystal display, comprising:

• a substantially transparent light guiding plate having a substantially rectangular shape;
• a frame formed to surround at least two sides of the light guiding plate;
• and
• a diffusion sheet covering an illuminated surface of the light guiding plate, wherein
• the light guiding plate and the frame are molded together to form a single unit resistant to deformation resulting from water absorption expansion in said single unit, and wherein materials for at least the light guiding plate and the frame are selected whose difference of water absorption coefficients of expansion is within a range of .+-.50%, relative to the water absorption coefficient of expansion of the material of the frame.

A backlighting apparatus for a liquid crystal display, comprising:

• a substantially transparent light guiding plate having a substantially rectangular shape;
• a frame formed to surround at least two sides of the light guiding plate;
• and
• a diffusion sheet covering an illuminated surface of the light guiding plate, wherein
• the light guiding plate and the frame are molded together to form a single unit resistant to deformation in said single unit resulting from expansion due to environmental effects, and including slits in at least one side of the frame, wherein the resistance to deformation is provided at least in part by the slits.

A backlighting apparatus for a liquid crystal display, comprising:

• a substantially transparent light guiding plate having a substantially rectangular shape;
• a frame formed to surround at least two sides of the light guiding plate;
• and
• a diffusion sheet covering an illuminated surface of the light guiding plate, wherein
• the light guiding plate and the frame are molded together to form a single unit resistant to deformation in said single unit resulting from expansion due to environmental effects, and including a plurality of through holes in the frame, extending in the thickness direction of the frame, wherein the resistance to deformation is provided at least in part by the through holes.

A backlighting apparatus for a liquid crystal display, comprising:

• a substantially transparent light guiding plate having a substantially rectangular shape;
• a frame formed to surround at least two sides of the light guiding plate;
• and
• a diffusion sheet covering an illuminated surface of the light guiding plate, wherein
• the light guiding plate and the frame are molded together to form a single unit resistant to deformation resulting from thermal or water absorption expansion in said single unit, and wherein
• materials for at least the light guiding plate and the frame are selected having a difference of thermal expansion coefficients within a range of .+-.50%, relative to the thermal expansion coefficient of the frame,
• materials for at least the light guiding plate and the frame are selected having a difference of water absorption coefficients of expansion within a range of .+-.50%, relative to the water absorption coefficient of expansion of the frame,
• the materials are an acrylic resin for the light guiding plate and wherein the frame comprises one of the set consisting of an acrylic resin, an alloy material of an acrylic resin and a polycarbonate resin, an alloy material of a polycarbonate resin and a vinyl resin, and a resin having a glass content of 20 to 40%, and wherein the diffusion sheet is attached to one of the set of the light guiding plate and the frame.

A backlighting apparatus for a liquid crystal display, comprising:

• a substantially transparent light guiding plate having a substantially rectangular shape;
• a frame formed to surround at least two sides of the light guiding plate;
• and
• a diffusion sheet covering an illuminated surface of the light guiding plate, wherein
• the light guiding plate and the frame are molded together to form a single unit resistant to deformation resulting from water absorption expansion in said single unit, and wherein materials for at least the light guiding plate and the frame are selected whose difference of water absorption coefficients of expansion is within a range of .+-.50%, relative to the water absorption coefficient of expansion of the material of the light guiding plate.

A backlighting apparatus for a liquid crystal display, comprising:

• a substantially transparent light guiding plate having a substantially rectangular shape;
• a frame formed to surround at least two sides of the light guiding plate;
• and
• a diffusion sheet covering an illuminated surface of the light guiding plate, wherein
• the light guiding plate and the frame are molded together by one piece molding to form a single unit resistant to deformation in said single unit resulting from expansion due to environmental effects,
• wherein the light guiding plate has a flange portion having a thickness smaller than that of a central portion thereof and projecting from at least one side thereof, the frame has a flange receiving portion corresponding to the flange portion, and wherein the flange portion is joined to the flange receiving portion such that a space is present between an end surface of the light guiding plate and an inner end surface of the frame.