Backlight unit and liquid crystal display apparatus employing the same

A liquid crystal display apparatus comprising:

• a liquid crystal panel;
• and
• a backlight including:
• a plurality of light-emitting device units disposed on a base plate in an array, each light-emitting device unit including a collimator to collimate light emitted by a light-emitting device so that the light propagates in a principal propagation direction,
• a plurality of side reflectors disposed in an array above the array of corresponding light-emitting device units, to reflect in lateral directions the light incident from the corresponding light-emitting device units,
• a reflective diffusion plate to reflect and diffuse light reflected by the side reflectors, and
• a transmissive diffusion plate that is disposed above the light-emitting device units, to transmit and diffuse the incident and reflected light toward the liquid crystal panel.

A method of providing a backlight to a panel, the method comprising:

• emitting light by an array of light-emitting device units disposed on a base plate in an array, each light-emitting device unit including a collimator to collimate light emitted by a light-emitting device so that the light propagates in a principal propagation direction;
• reflecting in lateral directions the light incident from the light-emitting units, by a plurality of side reflectors disposed above each light-emitting device unit;
• reflecting and diffusing the lateral reflected light;
• and
• transmitting and diffusing the light in the principal propagation direction.

A backlight unit comprising:

• a base plate;
• a reflective diffusing plate formed on the base plate;
• a plurality of light-emitting device units disposed on the reflective diffusing plate and spaced apart from each other to emit light in a principal propagation direction;
• a transmission diffusion plate spaced apart from the reflecting diffusing plate;
• and
• a plurality of side reflectors formed on the transmissive diffusion plate to reflect the light from corresponding ones of the plurality of light-emitting device units, in a lateral direction.

A method to form a backlight unit comprising:

• forming a base plate;
• forming a reflective diffusing plate formed on the base plate;
• placing a plurality of light-emitting device units on the reflective diffusing plate to be spaced apart from each other so that the light-emitting device units emit light in a principal propagation direction;
• forming a transmission diffusion plate to be spaced apart from the reflecting diffusing plate;
• and
• forming a plurality of side reflectors formed on the transmissive diffusion plate to reflect the light from each of corresponding light-emitting device units, in lateral directions.