Patent attributes
A method of and system for displaying a high bit depth pulse width modulated image at a low frame rate without image flicker. The frame period (1902) is divided into a series of refresh periods (1904, 1906, 1908, 1910). The more significant image bits (1912, 1914, 1916) are displayed in every refresh period, while the bits of lesser significance (1918, 1920, 1922) are displayed only during a subset of the refresh periods. The bits of lesser significance ideally are arranged out of phase with one another such that an equal, or comparable, duration of the lesser significant bit periods is included in each of the refresh periods. Because the minimum temporal frequency necessary to avoid flicker is greater for longer bit durations, this method provides a higher frequency for the more significant bits compared to the bits of lesser significance that are less likely to flicker. This provides the advantage of enabling greatly increase bit depth without requiring unnecessarily short bit planes.