초록 ▼

A method for expanding pulse width modulation sequences that control a display system to adapt to varying video frame times. A minimal amount of extra circuitry (10) is provided that regulates a sequencer (26). After calculating the appropriate expansion factor needed to stretch a base sequence, the

A method for expanding pulse width modulation sequences that control a display system to adapt to varying video frame times. A minimal amount of extra circuitry (10) is provided that regulates a sequencer (26). After calculating the appropriate expansion factor needed to stretch a base sequence, the system control circuit (22) sends that information to the circuitry (10). The circuitry (10) includes a counter (14) that repetitively counts down a number of clock cycles and causes the clock to drop a cycle. This dropping of clock cycles causes the sequence time to be expanded, as it takes the system longer to reach the necessary number of clock cycles that determine a sequence. Several base pulse width modulation sequences could be stored in memory, each of which can be used for a range of frame times, eliminating the need for one sequence for every possible variation in the frame time.

대표청구항 ▼

[ What is claimed is:] [1.] A method for controlling PWM sequence times in a display system, comprising the steps of:a) setting said PWM sequence time in said system to be substantially equal to a predetermined number of clock cycles of a sequencer clock;b) expanding said PWM sequence time by causin

[ What is claimed is:] [1.] A method for controlling PWM sequence times in a display system, comprising the steps of:a) setting said PWM sequence time in said system to be substantially equal to a predetermined number of clock cycles of a sequencer clock;b) expanding said PWM sequence time by causing said sequencer clock to drop counts, thereby delaying said sequencer clock reaching said predetermined number of clock cycles, resulting in an expanded PWM sequence time; andc) selecting one of a series of base pulse width modulation sequences, wherein said selection of said one sequence is based upon a display frame time.