Back light module
AssigneeChunghwa Picture Tubes, Ltd.
InventorsHan-Yu Chao, Chien-Lung Tsou
Life of this patent
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Abstract
A back light module is provided. The back light module includes a plurality of light source matrixes, a current adjusting circuit and a light source driving circuit, wherein each of the light source matrixes includes N light emitting units and N is an integer greater than 1. First ends of the light emitting units are electrically connected to each other, and a second end of the ith light emitting unit is electrically connected to an ith level switch line, wherein i is an integer and 1≦i≦N. The current adjusting circuit supplies and controls the current of each of the light source matrixes through level switch lines. The light source driving circuit drives the light source matrixes sequentially.
Claims13
A backlight module, comprising:
- a plurality of light source matrixes, wherein each of the light source matrixes is electrically connected to N level switch lines and comprises:
- N light emitting units, wherein first ends of the light emitting units are electrically connected to each other and a second end of the ith light emitting unit is electrically connected an ith level switch line, N being an integer greater than 1, i being an integer and 1≦i≦N;
- and
- a current adjusting circuit, electrically connected to the level switch lines to provide and control the current that flows through the light source matrixes;
- and
- a light source driving circuit, electrically connected to the first ends of the light emitting units of each of the light source matrixes to sequentially drive the light source matrixes, wherein the light source driving circuit comprises:
- a plurality of second switches, respectively corresponding to the light source matrixes, wherein first ends of the second switches receive a predetermined voltage, second ends of the second switches are electrically connected to the first ends of the light emitting units in the corresponding light source matrixes, and the light source driving circuit sequentially turns on the second switches in a frame period;
- and
- a level control circuit, for generating the predetermined voltage and adjusting a level of the predetermined voltage once in every dimming time so as to switch the level of the predetermined voltage to one of a plurality of specified levels.
A back light module, comprising:
- a light source driving circuit, for sequentially generating a plurality of driving pulses, wherein the light source driving circuit comprises:
- a plurality of second switches, wherein first ends of the second switches are use to receive a predetermined voltage, second ends of the second switches are used to provide the driving pulses, and the light source driving circuit sequentially turns on the second switches;
- and
- a level control circuit, for generating the predetermined voltage and adjusting a level of the predetermined voltage once in every dimming time so as to switch the level of the predetermined voltage to one of a plurality of specified levels;
- a plurality of light source matrixes, electrically connected to the light source driving circuits and N level switch lines and respectively driven according to the driving pulses, wherein N is an integer greater than 1, and each of the light source matrixes comprises:
- N light emitting units, wherein first ends of the light emitting units receive one of the driving pulses and a second end of the ith light emitting unit is electrically connected to the ith level switch line, i being an integer and 1≦i≦N;
- and
- a current adjusting circuit, electrically connected to the level switch lines to provide and to control a current that flows through the light source matrixes.
Dependencies are inferred from the claim text.