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: 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 method and system of increasing the intensity of secondary colors in sequential color display systems. The method utilizes light during a transition period between two primary color periods to form a secondary color. The light generated during this transition is generally not used since it does not represent a pure primary color, but instead typically starts as light of a first pure primary and ends as light of a second pure primary. A display controller determines which secondary color is needed, and the amount of the secondary color needed, and enables the transition or spoke light to contribute to the image during a time period appropriate to desired secondary color intensity given the intensity and switching characteristics of the light during the transition period. For example, light (210) filtered by a color wheel (200) during the transitional period (212 to 214) between a red (102) and green (106) filter is used to increase the yellow component of the image.

Abstract: A display system (902) and method for increasing the brightness of an image through the use of a color wheel (504) having white light generating segment. The display system comprises a RGBW processing function (906), a hue correction function (906), and a gain correction function (904). The RGBW processing function (906) includes circuitry to generate an intensity word for use during the white light generating segment. The hue correction function (906) includes circuitry to adjust the relative intensities of the primary color components to compensate for the addition of the white segment data. The gain correction function (904) includes circuitry to adjust the intensity of pixel data based on the white content of the pixel and the intensity of the pixel. After the pixel data is processed, it is formatted by data formatting logic (912) and displayed using a spatial light modulator (914).

Abstract: A method and display system for using the light (110) passing through the spokes of a color wheel (100). The light is a mixed and rapidly changing color. Adding all of the spoke times produces white, but adding a subset creates color artifacts. The spoke times cannot all be added at the same time without altering the white point of the display. The spoke times are added in a sequence and the sequence is altered over time for the same pixel such that the pixel converges to white over time. The pattern of spoke bits is arranged so that as adjacent spoke bit pixels are added, the net spoke light converges to white. The patterns are also varied so that as more and more spoke bit periods are turned on, the net spoke light converges to white. Each spoke bit period adds n-LSBs of white light intensity, so as each spoke bit period is added, n−I LSBs of white light are subtracted from the white data.

Abstract: A method and apparatus for controlling a lamp. A timer (106) reads a rated safe life value from a memory (102) associated with a lamp in a lamp module (104). The memory (102) in the lamp module (104) contains a series of locations in which the rated safe life of the lamp has been stored, and a series of locations for storing the elapsed on time of the lamp. The timer controller (106) reads the series of locations storing the rated safe life of the lamp and verifies the validity of the values using a series of checksums and comparisons between the various values. The timer controller (106) also reads the series of locations storing the elapsed on time for the lamp and verifies the elapsed on time in a similar manner. If either the rated safe on time or the elapsed on time cannot be verified, the lamp is disabled. If both can be verified, and the lamp is enabled until the elapsed on time equals or exceeds the rated safe life.

Abstract: A method and apparatus for controlling a lamp. A timer controller (106) reads a rated safe life value from a memory (102) associated with a lamp in a lamp module (104). The memory (102) in the lamp module (104) contains a series of locations in which the rated safe life of the lamp has been stored, and a series of locations for storing the elapsed on time of the lamp. The timer controller (106) reads the series of locations storing the rated safe life of the lamp and verifies the validity of the values using a series of checksums and comparisons between the various values. The timer controller (106) also reads the series of locations storing the elapsed on time for the lamp and verifies the elapsed on time in a similar manner. If either the rated safe on time or the elapsed on time cannot be verified, the lamp is disabled. If both can be verified, and the lamp is enabled until the elapsed on time equals or exceeds the rated safe life.

Abstract: A method and system for performing spatial temporal multiplexing using a multi-threshold mask. A mask generator (404) outputs a threshold value for each pixel of a display. The mask generator typically creates a blue noise mask for a given pixel array that is replicated over the face of the entire display. The blue noise mask generator (404) typically is implemented as a memory lookup table. An index generator (402) provides an offset into the memory lookup table that allows the table to be shifted from time to time. The output of the blue noise mask generator (404), which may be the threshold value itself or a signal representing which threshold is being used, is an input to a selective inverter (406). The selective inverter (406) provides the option of inverting the blue noise mask. To reduce artifacts, the mask is periodically shifted and/or inverted. The value from the mask generator (404), whether inverted or not, is compared to the LSBs of the input data word to yield the fractional bit values.

Abstract: A method and display system for using the light (110) passing through the spokes of a color wheel (100). The light is a mixed and rapidly changing color. Adding all of the spoke times produces white, but adding a subset creates color artifacts. The spoke times cannot all be added at the same time without altering the white point of the display. The spoke times are added in a sequence and the sequence is altered over time for the same pixel such that the pixel converges to white over time. The pattern of spoke bits is arranged so that as adjacent spoke bit pixels are added, the net spoke light converges to white. The patterns are also varied so that as more and more spoke bit periods are turned on, the net spoke light converges to white. Each spoke bit period adds n-LSBs of white light intensity, so as each spoke bit period is added, n−1 LSBs of white light are subtracted from the white data.

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: A method for performing pulse width modulation (PWM) on a binary spatial light modulator using spatial-temporal multiplexing. A 10% light boost is achieved by eliminating deadtimes that are typically generated using the global-reset operation of a DMD when bit-planes having small on times are utilized. The number of bit-planes required is reduced by using a combination of binary and ternary bit-planes to achieve grayscale of a displayed digital image. By using a combination of spatial and temporal processing, digital pixel values can be displayed using a reduced number of bit-planes, without generating perceived artifacts such as pulsing due to pixels being turned on-off from frame to frame.