Digital pixel driver with gradation control using pulse width modulation

Fuente: Wipo "digitalization"
A digital pixel driver that operates in response to an M-bit digital input value defining the apparent brightness of the pixel. The pixel driver generates a pixel drive signal having a duty cycle that sets the apparent brightness of the pixel. The pixel driver comprises a memory, a digital sequence generator and a comparator. The memory receives and stores an N-bit word that represents the digital input value. The digital sequence generator generates a digital sequence of P-bit digital values that defines the temporal duration of the pixel drive signal and includes a first P-bit word that represents at least part of the digital input value at a location temporally corresponding to the duty cycle of the pixel drive signal as defined by the at least part of the digital input value. The comparator is connected to receive the digital sequence from the digital sequence generator and a second P-bit word from the memory. The second P-bit word constitutes at least part of the N-bit word. The comparator includes an output that provides the pixel drive signal and that changes state in response to correspondence between the first P-bit word and the second P-bit word.