Liquid crystal display backlight control

Liquid crystal display (“LCD”) circuitry comprising:

• an LCD including a plurality of blocks of pixels arranged in a two-dimensional array of intersecting rows and columns of the blocks, each of the blocks including a respective plurality of the pixels;
• backlight circuitry for illuminating each block with a respective controllable amount of backlight;
• circuitry for determining a grayscale characteristic of pixel data applied to each of the blocks;
• circuitry for determining an amount of motion in the pixel data applied to each of the blocks, and for identifying a block as either still or moving depending on whether the image information for that block is still or moving, respectively, and additionally for identifying a block that is immediately adjacent to a moving block as a filtered block;
• and
• circuitry for determining the amount of backlight for each of at least some of the blocks by, at least in part, applying to the grayscale characteristic of that block at least one of a plurality of brightness functions;
• wherein:
• the at least one of the plurality of brightness functions is selected based on whether that block is only still, only moving, filtered and still, or filtered and moving.

A method of controlling backlighting of a plurality of portions (“blocks”) of a block-controllable display, the blocks being arranged in a two-dimensional array that is co-extensive with the display, a block including multiple pixels of the display, and a block having a respective backlight whose viewer-perceived brightness is controllable independently of the viewer-perceived brightness of other of the backlights, the method comprising for successive frames of image information supplied for display by the display:

• determining a grayscale characteristic of pixel data applied to each of the blocks;
• determining an amount of motion in the pixel data applied to each of the blocks, and identifying a block as either still or moving depending on whether the image information for that block is still or moving, respectively, and additionally for identifying a block that is immediately adjacent to a moving block as a filtered block;
• and
• determining the amount of backlight for each of at least some of the blocks by, at least in part, applying to the grayscale characteristic of that block at least one of a plurality of brightness functions;
• wherein:
• the at least one of the plurality of brightness functions is selected based on whether that block is only still, only moving, filtered and still, or filtered and moving.