Driving method for low consumption LCD modules

1 . A method for driving LCD modules having a multiplicity of display elements located at the intersections of a matrix having a plurality of row electrodes and a plurality of column electrodes, said method comprising the phases of:

applying an M bit electrical digital signal to at least one row electrode at a time, subdivided into a plurality of time intervals equal to 2 M −1;

said electrical digital signal suitable for illuminating each of said display elements with a predefined luminosity level chosen from among 2 M luminosity levels;

each of said M bits is applied for a preset duration; and

the preset duration of each of said M bits is then reduced in accordance with a predefined scale factor K and said M bits are subdivided into (2 M −1)/K pluralities of time intervals.

2 . The method of claim 1 wherein said M bits are combined with each other so as to reduce the number of possible switches.

3 . The method of claim 1 wherein said plurality of time intervals the bits that represent said 2 M luminosity levels in accordance with a predetermined scale of weights are subdivided.

4 . The method of claim 3 wherein said predetermined scale of weights assesses each bit for a preset number of said plurality of time intervals.

5 . The method of claim 4 wherein the instants of time in which a bit is assessed are distributed equally.

6 . The method of claim 1 wherein said scale factor K is determined so as to minimize current consumption of said LCD modules.

7 . The method of claim 1 wherein said scale factor K is determined so as to obtain a number of said plurality of time intervals in order to apply the technique known as Phase Tiling.

8 . The method of claim 1 wherein said scale factor K is determined so as to obtain a number of said plurality of time intervals equal to one from among 7, 11, and 13.

9 . A method for driving LCD modules having a plurality of display elements associated with a plurality of row electrodes and a plurality of column electrodes in a matrix, the method comprising:

illuminating each of the display elements with a predefined luminosity level chosen from among 2 M luminosity levels by applying an M-bit electrical digital signal to at least one row electrode at a time, the M-bit electrical digital signal subdivided into a plurality of time intervals equal to 2 M −1, each of said M-bits is applied for a preset duration; and

reducing the preset duration of each of said M-bits in accordance with a predefined scale factor K and subdividing M-bits into (2 M −1)/K plurality of time intervals.

10 . The method of claim 9 wherein the M-bits in the plurality of time intervals represent the 2 M luminosity levels in accordance with a predetermined scale of weights.

11 . The method of claim 10 wherein the predetermined scale of weights is used to assess each bit for a preset number of the plurality of time intervals.

12 . A method for driving LCD modules having a multiplicity of display elements coupled to a plurality of row electrodes and a plurality of column electrodes arranged in a matrix, the method comprising:

illuminating each of the display elements with a predefined luminosity level chosen from among 2 M luminosity levels by applying an M-bit electrical digital signal to at least one row electrode at a time, the M-bit electrical digital signal subdivided into a plurality of time intervals equal to 2 M −1, each of said M-bits is applied for a preset duration; and

reducing the preset duration of each of said M-bits in accordance with a predefined scale factor K.

13 . The method of claim 12 , further comprising subdividing the M-bits into (2M-1)/K pluralities of time intervals.

14 . The method of claim 13 wherein the scale factor K is determined so as to obtain a number of the plurality of time intervals in order to apply a Phase Tiling technique.

15 . The method of claim 12 wherein the scale factor K is determined so as to obtain a number of the plurality of time intervals equal to one from among 7, 11, and 13 time intervals.

16 . An LCD module, comprising:

an LCD display device having a multiplicity of display elements coupled to a plurality of row electrodes and a plurality of column electrodes arranged in a matrix; and

a circuit for driving the display elements, the circuit configured to illuminate each of the display elements with a predefined luminosity level chosen from among 2 M luminosity levels by applying an M-bit electrical digital signal to at least one row electrode at a time, the M-bit electrical digital signal subdivided into a plurality of time intervals equal to 2 M −1, each of said M-bits is applied for a preset duration, and then to reduce the preset duration of each of the M-bits in accordance with a predefined scale factor K and subdividing the M-bits into (2 M −1)/K plurality of time intervals.

17 . An LCD module, comprising:

an LCD display device comprising a multiplicity of display elements coupled to a plurality of row electrodes and a plurality of column electrodes arranged in a matrix; and

a driving circuit for driving the display elements by illuminating each of the display elements with a predefined luminosity level chosen from among 2 M luminosity levels by applying an M-bit electrical digital signal to at least one row electrode at a time, the M-bit electrical digital signal subdivided into a plurality of time intervals equal to 2 M −1, each of said M-bits is applied for a preset duration, and then reducing the preset duration of each of said M-bits in accordance with a predefined scale factor K.

18 . The module of claim 17 wherein the driver circuit is configured to subdivide the M bits into (2 M −1)/K pluralities of time intervals.

19 . The module of claim 18 wherein the scale factor K is determined to obtain a number of the plurality of time intervals in order to apply a Phase Tiling technique.

20 . The module of claim 18 wherein the scale factor K is determined so as to obtain a number of the plurality of time intervals equal to one from among 7, 11, and 13 time intervals.