Stereoscopic image display and method of controlling backlight thereof

摘要

A stereoscopic image display device comprises a frame rate conversion unit that divides 3D input data into left eye image data and right eye image data, inserts reset frame data containing black grayscale data between the left eye image data and the right eye image data, and generates the (n+1)-th frame data to the (n+4)-th frame data containing the left eye image data, the black grayscale data, the right eye image data, respectively, and the black grayscale data, a look-up table that stores local dimming values used to control brightness for the overall local dimming zones to the minimum during the (n+2)-th and (n+4)-th frame periods, and local dimming values used to control brightness for each local dimming zone to target brightness during the (n+1)-th and (n+3)-th frame periods, and a backlight controller that controls light source brightness of the backlight unit for each local dimming zone.

主权项

1. A stereoscopic image display device, comprising:
a liquid crystal display panel having a plurality of gate lines, a plurality of data lines, and a plurality of pixels arranged at intersections of the gate lines and the data lines, and where frame data is addressed in an order of a (n+1)-th (where n is a positive integer) frame data to a (n+4)-th frame data; a backlight unit of which an emission surface is divided into local dimming zones which can be controlled in brightness and which provides light to the liquid crystal display panel, each local dimming zone corresponding to one or more pixels of the liquid crystal display panel; a frame rate conversion circuit configured to divide 3D input data into left eye image data and right eye image data, to insert reset frame data containing black grayscale data between the left eye image data and the right eye image data, and to thereby generate the (n+1)-th frame data containing the left eye image data, the (n+2)-th frame data containing the black grayscale data, the (n+3)-th frame data containing the right eye image data, and the (n+4)-th frame data containing the black grayscale data; a local dimming value selection circuit configured to receive the (n+1)-th to the (n+4)-th frame data from the frame rate conversion circuit, to select a local dimming value used to control brightness for the overall local dimming zones of the backlight unit to the minimum during the (n+2)-th and (n+4)-th frame periods regardless of a preceding frame data, and to select a local dimming value used to control brightness for each local dimming zone of the backlight unit to a respective target brightness for the left eye image data or the right eye image data during the (n+1)-th and (n+3)-th frame periods, wherein, for the (n+1)-th and (n+3)-th frame periods, when the brightness of a frame data of the local dimming zone two frames earlier is greater than the brightness of the current frame data of the local dimming zone, the local dimming value selection circuit selects the local dimming value of the associated local dimming zone to reduce the brightness of the local dimming zone and to reach the target brightness of a corresponding pixel data for the current frame, and when the brightness of the frame data of the local dimming zone two frames earlier is less than the brightness of the current frame data of the local dimming zone, the local dimming value selection circuit selects the local dimming value of the associated local dimming zone to increase the brightness of the local dimming zone and to reach the target brightness of the corresponding pixel data for the current frame; and a backlight controller configured to control light source brightness of each local dimming zone of the backlight unit, depending on the associated local dimming value output from the local dimming value selection circuit, wherein the local dimming zones are arranged in a plurality of columns and a plurality of rows, and wherein the left eye image data includes left eye RGB data, and the right eye image data includes right eye RGB data.