Abstract: An electronic method for addressing and synchronizing a spatial light modulator (SLM) device when used with color scrolling recovery (SCR) illumination. This method applies all the colors to a single SLM simultaneously and recaptures secondary light, redirecting it along the primary color paths to significantly improve the brightness in single-chip display applications. The SCR concept requires multiple colors to be imaged on to an SLM array simultaneously. This requires that the SLM be divided into reset groups so that separate groups of pixels can project bits from the different colors at the same time. As these color bands 602, 604, 606 scroll across the array, the various reset groups tracks these regions and change content to match. The method requires that the device be divided and controlled at an independent reset group level, with each group being delayed by a group_skew time 608 from the previous group.

Abstract: An SLM PWM clocking method, called “jog clear,” for generating short bit periods where block data clears (74) are inserted between block data loads (72, 76) within a frame refresh period. The method significantly reduces the short bit duration that requires use of the earlier reset-release method and it eliminates undesirable artifacts present in these earlier SLM clocking methods.

Abstract: A method and system of detecting whether the intensity of light incident a spatial light modulator varies periodically. One embodiment provides a method of operating a spatial light modulator, the method comprising: determining a peak level of light incident the modulator over a period of time; setting a threshold level equal to a fraction of the peak level; monitoring a current level of light incident the modulator; comparing the current level of light and the threshold level; and disabling the modulator based on the comparison. Another embodiment provides a modulator array.

Abstract: A display system 100 includes a light source 110 and a color wheel 114. An optical section 112 is arranged to receive light from the light source 110 and to direct the light toward a color wheel 114. A digital micromirror device 122 is arranged to receive the light from the color wheel 114 and to direct image data toward a display. The image data includes an array of pixels arranged in rows and columns. The array of pixels is arranged as curved color bands during a first time period and rectangular color bands during a second time period. The second time period being concurrent with but of a shorter duration than the first time period.

Abstract: A display system includes a light source 110 and a spatial light modulator 122 located to receive light from the light source. The spatial light modulator (e.g., a DMD) includes a number of independently controllable elements that are activated for a period of time to display light of a desired brightness. A light sensor 136 is located to determine a characteristic of light from the light source 110. A control circuit 126 is coupled to the spatial light modulator 122 and controls the period of time that the independently controllable elements are activated. This period of time is based at least in part by an input received from the light sensor 136.

Abstract: An electronic method for addressing and synchronizing a spatial light modulator (SLM) device when used with color scrolling recovery (SCR) illumination. This method applies all the colors to a single SLM simultaneously and recaptures secondary light, redirecting it along the primary color paths to significantly improve the brightness in single-chip display applications. The SCR concept requires multiple colors to be imaged on to an SLM array simultaneously. This requires that the SLM be divided into reset groups so that separate groups of pixels can project bits from the different colors at the same time. As these color bands 602, 604, 606 scroll across the array, the various reset groups tracks these regions and change content to match. The method requires that the device be divided and controlled at an independent reset group level, with each group being delayed by a group_skew time 608 from the previous group.

Abstract: A method for using pulse-width modulation in displays. A series of PWM sequences is established. Each subsequent sequence clears the previous sequence before it, eliminating the need for a separate clearing reset at the end of the previous sequence. This allows for use of spoke bits in color-sequential systems. In non-color sequential systems and rapid color-switching systems it allows the sequence for one frame to flow directly into the sequence for the next frame.

Abstract: A method of addressing an array of spatial light modulator elements. The method divides the array into blocks of elements, provides reset lines (MRST) to each of the block of elements, separate from the other blocks of elements, as well as address voltage supplies (VCCADDR) to each of the block of elements, separate from the other blocks of elements, addresses data to each of the blocks independent of the other blocks, resets each of the blocks, and steps address voltage to each of the block, where only blocks that are being reset receive the stepped address voltage. A spatial light modulator array (32) is also provided that has a layout to facilitate the method, including internal or external circuitry (34) to provide control of the stepped addressing voltages.

Abstract: A spatial light modulator clocking method, called fast-clear, which employs embedded clear hardware in the SLM to enable the fast-clear bit to generate least-significant short-bit periods and without any bit ordering restrictions. In this method, fast data clears 34 are inserted between block data loads 32,36 within a frame refresh period. This method virtually eliminates the artifacts associated with the earlier reset-release timing method without the bit-ordering restriction of the jog-clear method.

Abstract: A method and system of detecting whether the intensity of light incident a spatial light modulator varies periodically. One embodiment provides a method of operating a spatial light modulator, the method comprising: determining a peak level of light incident the modulator over a period of time; setting a threshold level equal to a fraction of the peak level; monitoring a current level of light incident the modulator; comparing the current level of light and the threshold level; and disabling the modulator based on the comparison. Another embodiment provides a modulator array.

Abstract: An SLM PWM clocking method, called “jog clear,” for generating short bit periods where block data clears (74) are inserted between block data loads (72, 76) within a frame refresh period. The method significantly reduces the short bit duration that requires use of the earlier reset-release method and it eliminates undesirable artifacts present in these earlier SLM clocking methods.

Abstract: A method and apparatus for spatially and temporally multiplexing display data. The use of this method results in a bit-depth resolution higher than that achievable by the system given a number of bits of resolution. The method includes the steps of determining the desired perceived resolution (26), establishing the number of bit-planes to be used to achieve that perceived resolution (28), using at least one of those bit-planes for spatial-temporal least significant bit values (STMLSBs) (30), referencing the developed values of the STMLSBs to fractional bit gray code levels (32), developing spatial patterns (34), determining whether the spatial patterns will start in a predetermined sequence or randomly from frame-to-frame (36), loading the data onto the modulator and displaying it (38). The apparatus includes a random number generator (48) and a look up table (50) to enable the choice between random and predetermined spatial patterns, and pattern logic (46), which produces the pattern to be used.

Abstract: An SLM-based video receiver (10) receives a video input of some standardized format at a signal interface unit (11) and passes the input to a processor (12). The processor (12) performs analog-to-digital conversion if the pixel data is analog and also performs other enhancements to prepare the pixel data for loading into a video memory (14). The pixel data from the processor (12), representing a field of pixel data, is stored into the memory (14) for loading into rows of pixel elements of a spatial light modulator (16). The spatial light modulator (16) receives the pixel data in rows and each individual pixel element responds accordingly. The pixel elements of the spatial light modulator (16) emit light or reflect light from a source (18) and generate a video frame for display on a screen (20). By exploiting the addressing functions of the spatial light modulator (16), the SLM-based video receiver (10) displays a video frame using a field of pixel data.

Abstract: A display memory (15) for a display system (10, 20) having a spatial light modulator (SLM) (16). The memory (15) receives data in pixel format and delivers the data to the SLM (16) in bit-plane format. The memory (15) avoids the need for double buffering by reading out bit-planes that are comprised partly of data from one data from and partly of data from an adjacent data frame.

Abstract: A controller (800) for a pulse width modulated display system. The controller (800) periodically determining the output of a light source by sampling the output of a light detector (808) an creating a smoothed approximation of the periodic waveform of the light source. A processor (806) in the controller (800) reads a base bit split sequence from a read only memory (804) and modifies the sequence by lengthening or shortening the bit periods described therein in order to compensate for the periodic variations of the light source. The modified bit split sequence is stored in two-port random access memory (802) where it is later accessed by both the processor (806) and a sequencer (304). The sequencer (304) reads the modified bit split sequence from the two-port random access memory (802) to determine when to load each bit of image data into a modulator an-ay.

Abstract: A method of addressing an array of spatial light modulator elements. The method divides the array into blocks of elements, provides reset lines (MRST) to each of the block of elements, separate from the other blocks of elements, as well as address voltage supplies (VCCADDR) to each of the block of elements, separate from the other blocks of elements, addresses data to each of the blocks independent of the other blocks, resets each of the blocks, and steps address voltage to each of the block, where only blocks that are being reset receive the stepped address voltage. A spatial light modulator array (32) is also provided that has a layout to facilitate the method, including internal or external circuitry (34) to provide control of the stepped addressing voltages.

Abstract: A method of implementing pulse-width modulation in a display system (10, 20) that uses a spatial light modulator (SLM) (15). Each frame of data is divided into bit-planes, each bit-plane having one bit of data for each display element of the SLM and representing a bit weight of the intensity value to be displayed by the display elements. Each bit-plane has a display time corresponding to a portion of the frame period, with bit-planes of more significant bits having longer portions. The SLM is divided into reset groups connected to different reset lines (34), so that one reset group can be loaded and its display time begun while the next reset group is loaded. (FIG. 3). Short bit-planes are possible because the display time need not include the time to load the entire array, and for any reset group, its reset can be delayed while other reset groups are loaded.

Abstract: A sequence controller (18) for controlling load/reset sequences for a spatial light modulator (15). The sequence controller has a program memory (41) for storing load instructions and reset instructions. A load control processor (42) executes load instructions. A reset control processor (43) executes reset instructions. The two processors (42, 43) operate independently except for synchronization.

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 automatically generating a load/reset sequence for a display system having a spatial light modulator whose display elements that are loaded with data and reset between loads (FIG. 7). Bit-planes of data are classified according to their display times as normal, short, or reset-release (FIG. 5). Extra time of normal bit-planes is calculated (FIG. 5). The display times of normal bit-planes are adjusted by subtracting or adding extra time, such that any normal bit-plane displayed before a short or reset-release bit-plane includes sufficient extra time to allow for loading the short or reset-release bit-plane (FIG. 7). Also, reset conflicts are detected and avoided (FIGS. 7, 8, 9A and 9B).