Abstract: Methods of controlling the illumination source (18) of an SLM-based display system (10). It is assumed that the system (10) displays pixel data formatted into a bit-plane format so that all bits of the same bit-weight can be displayed simultaneously. To provide greyscale, the amplitude of the source (18) may be modulated so that bit-planes having greater bit-weights are displayed with more intense illumination than bit-planes having smaller bit-weights (FIGS. 2 and 3). To avoid visual artifacts, the duty cycle of the bit-plane display times may be shortened relative to the frame period. (FIG. 4A). The latter method can be accompanied by a shortening of the duty time of the illumination on SLM (15). (FIG. 4B). The short duty cycle method may be used together with illumination amplitude modulation, or it may be used with the PWM method of providing greyscale.

Abstract: A method of evaluating pulse width modulation patterns for a spatial light modulator display device. The method makes use of a light difference series function. This series function is obtained by representing on or off times of a display element as a light function. (FIG. 3). Two such light functions can be subtracted to compare two different patterns on the same display element (interframe) or to compare the same pattern on different display elements (intraframe). (FIG. 4). The result of the subtraction is a light difference function (FIG. 5), which can be expressed as a series function. Mathematical expressions using the series function correlate to various optical characteristics.

Abstract: A method of controlling the display period of video data, and system thereof, that matches the frame period of displayed video data to the speed of a color wheel. The period of the color wheel is measured to determine the display period. An optimum frame sequence pattern is selected, based on the display period, to minimize the artifacts created in the displayed image while maximizing the portion of the frame period used to display the image data. The display period for each segment of the frame sequence pattern is scaled to fit the period of the color wheel, and each bit of the image data is loaded into the spatial light modulator and displayed at the proper time.

Abstract: A DMD spatial light modulator (20) having an improved reset waveform (80) that improves the electrostatic control over the DMD mirrors (30) during switching states (T3). An intermediate bias level is provided to the yoke (32) and mirror (30) during the mirror reset cycle (T3) which is sufficient to maintain a voltage differential between the mirror/yoke and the address electrodes (26,28,50,52) to dynamically park the mirror during a same-state transition, but which voltage differential is insufficient to overcome the hinge restoration forces during an opposite-state transition such that the mirror releases toward the neutral position and can be captured in the other state upon reapplication of the bias voltage. The transition bias level is maintained for a sufficient time period (T3) to allow the mirror/yoke to release from the landing pads (82) a sufficient distance toward the neutral position.

Abstract: A method for causing a micromechanical spatial light modulator to display data for a period less than its settling time. The modulator elements receive a first pulse (40) that causes them to release from their previous state, a bias voltage is removed and reapplied, allowing the elements to move to the unaddressed state, and then the elements receive a second pulse (46). After receiving a second pulse, the elements assume an unaddressed state. In one embodiment, new address data is loaded during this unaddressed state, after which a bias is reapplied causing them to achieve the state corresponding to the new state. In another embodiment, the previous addresses are cleared during the unaddressed state, forcing the elements into an OFF state. In either embodiment, a reset pulse may be applied after either the load or clear step.

Abstract: A method of implementing pulse-width modulated image display systems (10, 20) with a spatial light modulator (SLM) (15) configured for split-reset addressing. Display frame periods are divided into time slices. Each frame of data is divided into bit-planes, each bit-plane having one bit of data for each pixel element and representing a bit weight of the intensity value to be displayed by that pixel element. Each bit-plane has a display time corresponding to a number of time slices, with bit-planes of higher bit weights being displayed for more time slices. The bit-planes are further formatted into reset groups, each reset group corresponding to a reset group of the SLM (15). The display times for reset groups of more significant bits are segmented so that the data can be displayed in segments rather than for a continuous time. During loading, segments of corresponding bit-planes are temporally aligned from one reset group to the next.