| 摘要 |
A method and apparatus for displaying a video picture on a matrix array of light emitting elements form of m rows and n columns of such elements. The video signal, which is comprised of periodic vertical intervals, each containing successive line intervals of video information, is sampled at a rate of n samples during each line interval. The resultant, n sampled picture elements for each sampled line interval in each vertical interval are stored. During a vertical interval, a given light emitting element, such as the i-th element in the j-th row, corresponding to a sampled picture element in a respective line interval, is energized for a duration greater than a line interval and less than a vertical interval as a function of the brightness of the sampled picture element when that sampled picture element is between and black and peak white levels. In a practical embodiment, a storage circuit stores the n sampled picture elements in each line in an mxn matrix array of storage elements. These stored, sampled picture elements are recirculated on a row-by-row basis periodically, all of the sampled picture elements being fully recirculated in a period which is less than the vertical interval. Each of the m rows of light emitting elements are conditioned sequentially are repetitively, in synchronism with the recirculation of the sampled picture elements in the storage circuit. A reference voltage generator generates a reference voltage of staircase waveform during each vertical interval, the step interval of the staircase waveform being equal to the aforementioned period. During each such period, the brightness of each picture element which is shifted into the first row of the storage circuit is compared to the reference voltage, and the columns of light emitting elements are selectively enabled for a duration that is a function of the brightness level of corresponding sampled picture elements. A light emitting element is energized if it is disposed in a row which is conditioned and in a column which is enabled. |
