	US 12,469,471 B2
	Pulse width modulation for phase-modulating display
Ian Kyles, West Linn, OR (US); and Howard V. Goetz, Tigard, OR (US)
Filed by Ian Kyles, West Linn, OR (US)
Filed on Feb. 13, 2024, as Appl. No. 18/440,675.
Claims priority of provisional application 63/487,795, filed on Mar. 1, 2023.
Prior Publication US 2024/0296811 A1, Sep. 5, 2024
Int. Cl. G09G 3/36 (2006.01)

CPC G09G 3/3696 (2013.01) [G09G 3/3607 (2013.01); G09G 2300/0857 (2013.01); G09G 2310/027 (2013.01); G09G 2310/0289 (2013.01)]

20 Claims

1. A method for controlling a liquid crystal pulse width modulated display, the method comprising:

determining a desired number N of pulses of a unit duration over a repetition period, the repetition period consisting of:

a first number A of group periods;

each group period consisting of a second number B of modulation intervals; and

each modulation interval comprising a third number (C−1) of unit durations followed by, for each modulation interval except a final modulation interval of a final group period, an additional unit duration;

such that the repetition period spans (A×B×C)−1 unit durations;

determining a group period baseline number of pulses D equal to an integer quotient of a Euclidean division of N by A;

determining a modulation interval baseline number of pulses H equal to an integer quotient of a Euclidean division of D by B;

determining a main segment modulation interval pattern consisting of H unit duration pulses at the first H unit durations of each modulation interval;

determining a repetition period remainder L2 equal to the integer remainder of the Euclidean division of N by A;

determining a group period remainder L equal to the integer remainder of the Euclidean division of D by B;

determining a baseline group period pattern consisting of:

the main segment modulation interval pattern applied to each modulation interval of the group period; and

an additional L unit duration pulses allocated to a unit duration following the first H unit durations of each of L modulation intervals selected from the group period; and

determining a repetition sequence for the repetition period consisting of:

the baseline group period pattern repeated for each group period of the repetition period; and

an additional L2 unit duration pulses allocated to a unit duration following the first H unit durations of a final modulation interval of each of L2 group periods selected from the repetition period; and

generating a drive sequence for controlling the liquid crystal pulse width modulated display, the drive sequence comprising the repetition sequence repeated one or more times.