Method and apparatus for controlling the partitions of a backlight unit of a 3D display apparatus

A three-dimensional (3D) display apparatus comprising:

• a liquid crystal display (LCD) unit including a plurality of partial regions;
• said LCD display unit displaying an image of an input 3D video sequence;
• a backlight unit partitioned into a plurality of sub-blocks that separately emit light to the LCD unit;
• a light guide plate delivering the light emitted from the backlight unit;
• and
• the backlight unit includes a control unit which controls light sources of the backlight unit,
• wherein the control unit of the backlight unit comprises:
• a sub-block turn-on time determining unit which determines image brightness of the 3D video sequence displayed on the LCD unit, for each of partial regions of the LCD unit to which the plurality of sub-blocks of the backlight unit emit light;
• said sub-block turn-on time determining unit determining turn-on times for the plurality of sub-blocks of the backlight unit, based on an image brightness level of each of the partial regions of the LCD unit;
• and
• the sub-block turn-on period determining unit determines turn-on periods for the plurality of sub-blocks of the backlight unit
• said sub-block turn-on period determining unit synchronizing with a frame period of the 3D video sequence and a switching period between a set including a left visual point frame and a right visual point frame, of the 3D video sequence,
• wherein a turn-on time for a sub-block of the backlight unit indicates time duration from a turn-on point to a turn-off point of the sub-block of the backlight unit, and
• wherein a turn-on period for a sub-block of the backlight unit indicates time duration from the turn-on point to the subsequent turn-on point of the sub-block of the backlight unit,
• wherein the control unit of the backlight unit repeatedly turns on and off each of the plurality of sub-blocks of the backlight unit, the turn-on and turn-off is based on both the turn-on times and the turn-on periods of the plurality of sub-blocks of the backlight unit, which are separately adjusted by being synchronized with a frame period of the 3D video sequence,
• wherein the sub-block turn-on time determining unit differently determines the turn-on times for the plurality of sub-blocks of the backlight unit with respect to same frame,
• wherein the sub-block turn-on period determining unit determines the turn-on periods of the sub-blocks of upper backlight unit to be longer from one sub-block to a next sub-block along a first direction, and determines the turn-on periods of the sub-blocks of lower backlight unit to be shorter from one sub-block to a next sub-block along the first direction.