LED tile Luminance control circuitry and display containing the same
Exemplary embodiments include a backlight assembly for a display wherein the backlight assembly is comprised of a plurality of tiles. Each tile has a plurality of lights attached to it, such that when a single light or group of lights fail, the tile may be replaced without having to replace the entire backlight assembly. The current draw and/or illumination of each tile is calibrated and maintained throughout the life of the display to ensure a uniform distribution of light across the backlight assembly.
1 . A backlight assembly for a display comprising:
a mounting structure;
a plurality of tiles removably attached to said mounting structure;
a plurality of LEDs attached to each of said tiles;
electrical connections for each LED within each tile;
a means for controlling the current flow through the electrical connections of each tile; and
removable electrical connections for each tile.
2 . The backlight assembly from claim 1 wherein:
said tiles are comprised of printed circuit boards (PCBs).
3 . The backlight assembly from claim 2 wherein:
said PCBs are comprised of metal core PCBs.
4 . The backlight assembly from claim 1 wherein:
said tiles are removable from the back of the display.
5 . The backlight assembly of claim 1 wherein:
said means for controlling the current flow through the electrical connections of each tile comprises a pulse width modulating driver control integrated circuit.
6 . The backlight assembly of claim 1 further comprising:
an inductor in series with said LEDs.
7 . The backlight assembly of claim 1 wherein:
the electrical connections for the LEDs within each tile comprises a plurality of LED groups connected in series where each LED group comprises a plurality of LEDs connected in parallel.
8 . A liquid crystal display (LCD) having a rear and front, said LCD comprising:
a backlight assembly in the rear of the display, comprising:
a mounting structure;
a plurality of tiles removably attached to said mounting structure, wherein each tile can be attached and detached from the mounting structure through the rear of said display;
a plurality of LEDs attached to each of said tiles;
electrical connections for each LED within each tile; and
removable electrical connections for each tile.
a means for controlling the current flow through the electrical connections of each tile; and
an LCD stack in the front of the display and aligned with said backlight assembly.
9 . The backlight assembly from claim 8 wherein:
said tiles are comprised of printed circuit boards (PCBs).
10 . The backlight assembly from claim 9 wherein:
said PCBs are comprised of metal core PCBs.
11 . The backlight assembly of claim 8 wherein:
said means for controlling the current flow through the electrical connections of each tile comprises a pulse width modulating driver control integrated circuit.
12 . The backlight assembly of claim 11 further comprising:
an inductor in series with said LEDs.
13 . The backlight assembly of claim 1 wherein:
the electrical connections for the LEDs within each tile comprises a plurality of LED groups connected in series where each LED group comprises a plurality of LEDs connected in parallel.
14 . A static display comprising:
a power source;
a mounting structure;
a plurality of tiles removably attached to said mounting structure, each tile comprising:
a first group of LEDs comprising a plurality of LEDs connected in parallel;
a positive conduction line connected to said power source and to said first group of LEDs;
a second group of LEDs comprising a plurality of LEDs connected in parallel, wherein said second group of LEDs is connected in series to said first group of LEDs; and
a negative conduction line connected to said second group of LEDs and returning to said power source;
a control box electrically removably connected to each tile, said control box comprising;
a means for controlling the current flow through the conduction lines of each tile; and
an image adapted to be illuminated by said LEDs.
15 . The display of claim 14 further comprising:
a light diffusing element positioned between said image and said plurality of tiles.
16 . The display of claim 14 wherein:
said means for controlling the current flow through the conduction lines of each tile comprises a pulse width modulating driver control integrated circuit.
17 . The display of claim 14 wherein:
said tiles are comprised of printed circuit boards (PCBs).
18 . The display of claim 17 wherein:
said PCBs are comprised of metal core PCBs.
19 . The display of claim 14 wherein each tile further comprises:
a third group of LEDs comprising a plurality of LEDs connected in parallel; and
wherein said third group of LEDs is connected in series to said second group of LEDs and to said negative conduction line returning to said power source.
20 . The display of claim 19 wherein each tile further comprises:
an inductor in series with said third group of LEDs and said power source.