Abstract: A method for printing grayscale images. A sliding window memory stores an array of exposure data. The memory is initialized (80) with zero values. The memory is then addressed (82) so that the last row of the array is filled with exposure data. A microimage is then generated based on the exposure data (84). The data in the array is then decremented (86). If the page to be printed is not completed, the array's addresses are rotated (82) so that the data for the first row drops out, the data for other rows is readdressed as the next row, and new data fills the last row.

Abstract: Higher quality printing is difficult in implementation in spatial light modulator printers. The two major problems are accomplishing gray scale within the line time constraints, and eliminating staircasing artifacts within the images printed (81). It can be improved by using an alternate way of resetting cells on the spatial light modulator when data is being loaded onto the cells, timing delay (86), horizontal offset (84), and differently sized pixels (80, 82).

Abstract: An optical guide (10, 40, 50, 60) for horizontally aligning two vertically stacked images generated by one or two SLMs. The optical guide has a channel separator (10a) that directs both images along two different paths. A pair of aligning reflectors (10b and 10c) on each path vertically shift the images with respect to each other so that at least part of the images on the first path are aligned side-by-side with at least part of the images on the second path. The channel separator (10a) then redirects the images to the image plane 15. Along both paths, at least two of the reflecting surfaces of channel separator (10a) or aligning reflectors (10b and 10c) are optically powered so as to change the width or height of the images.

Abstract: A motor control unit (15c) for synchronizing a color wheel (15) to an incoming video signal and for re-synchronizing the color wheel after a channel change. The motor control unit (15c) has an error control unit (31), which detects an out-of-phase condition, and derives a color wheel sync signal from the pixel sample clock adjusted by any phase error. A drive unit (33) phase locks this sync signal to an index signal provided by the color wheel. The result is a tightly controlled re-synchronization that minimizes perceived effects.

Abstract: Various light collection systems (10, 20, 30), for providing light to be reflected from, or transmitted by, an SLM. Two systems (10, 20) include reflectors (11, 21), which are designed to collect rear-emitted light from a source, as well as lenses (12, 22) having low f-numbers and achromatic transmission, and may include an integrator (14, 23). A third system (30) includes a special reflector (31) coupled directly to an integrator (33).

Abstract: An optical guide for horizontally aligning two vertically stacked images generated by one or two SLMs. The optical guide has a beam splitter that directs both images along two different paths. A first and a second aligning reflectors each disposed along each path for aligning the images. The beam splitter then redirects the images to the image plane 15. Along both paths, at least the aligning reflectors are optically powered so as to change the width or height of the images.

Abstract: A method of detecting and compensating for colors displayed by a display system (10) that uses a light source (16) and a color wheel (15). A desired color balance is specified in terms of a power ratio of three primary colors. This ratio is then compared to the actual power of light filtered through each color of the color wheel. (FIGS. 2A, 2B). In a first embodiment, the filter transmission characteristics are adjusted. (FIG. 3). In a second embodiment, the size of the color wheel's segments are changed as well as the display times for data corresponding to each segment. (FIG. 4). The two embodiments can also be combined to achieve a desired color balance.

Abstract: An intelligent printing system (110). The overall system has a light-imaging subsystem (120), an electrophotography subsystem (130) and a printing substrate subsystem (140). The system processor (126) monitors all of the characteristics of the system, including toner content and quantity, photoreceptor wear and usage, heat of the fuser, quantity of printing substrates remaining, power of the light source, and profile of a spatial light modulator. The monitored processes are used to adjust the printing process so that the maximum print quality is achieved. Additionally, the information received assists in maintaining the highest level of quality functioning of the system through the maintenance cycle.

Abstract: A device for patterning an imaging member (46) is provided. The device comprises a light source (24) which emits light rays (26). Light rays (26) pass through a collimator lens (28) to collimate the light rays (30). The light then strikes a spatial light modulator (32) which is controlled by a computer (40) to reflect the light (42). The light passes through an imaging lens (44) to magnify the pattern for striking imaging member (46). Imaging member (46) is thus patterned by changing modulator (32) by computer (40).

Abstract: A method of adjusting color temperature of images displayed by a display system (10) whose images are based on sequential pixel data and are filtered with a color wheel (15, 15', 15"). The relative display times for each color are adjusted to result in a corresponding adjustment of color temperature. In a first embodiment (FIG. 2), the size of the color wheel's segments are changed as well as the display times for data corresponding to each segment. In a second embodiment (FIG. 3), the display times for data corresponding to one or more segments are decreased with a black display time to fill in the difference.

Abstract: A digital micro-mirror device (10), whose contacting elements (11, 17) are not prone to stick together. In the case of a deflecting mirror device, landing electrodes (17) are covered with a grating (19), which reduces the contacting area but still permits conduction between the mirror (11) and the landing electrode (17). Alternatively, the landing electrode (17) can be fabricated as a grated surface.

Abstract: A formatter (13) for formatting data for use by a spatial light modulator (15) in an image display system (10). The formatter (13) converts data from pixel format to bit-plane format. The formatter (13) has a square array of memory cells (41), which are connected so that they can shift data either across the array from column to column (vertically) or down the array from row to row (horizontally). The loading of data to the array is toggled between vertical and horizontal loading (FIGS. 6A-6D). While the array is loaded vertically from one side, data is shifted out of the array at the other side. While the array is loaded horizontally from the top, data is shifted out at the bottom. Because of the orthogonal input versus output, the output data is arranged by bit-weight rather than by pixel.

Abstract: A SLM-based projection display system (10) samples and processes video data for delivery to a spatial light modulator (SLM) (13c), and uses a color wheel (14a) to color the SLM-generated images. A frame memory (13b) provides data to the SLM (13c) and is managed so that, if the phase of the incoming video signal changes, a desired phase relationship between the color wheel position and the data available to the SLM (13c) can be maintained. Also, a motor control unit (15a) uses a horizontal sync signal to generate a drive signal for the color wheel motor (16a), which limits the transient time during phase-changing events, and which provides a means for adjusting the phase of the drive signal.

Abstract: A method of reducing artifacts in SLM-based display systems (10, 20), whose images are based on data displayed by bit-weight for pulse-width modulated intensity levels. The method can be used with a multiple spatial light modulators SLM system (20), which concurrently displays images of different colors, or with a single SLM system (10), which generates differently colored images sequentially during each frame period. For a multiple SLM system (20), the method is used with SLMs (14) that are memory-multiplexed, having "reset groups" that are loaded and displayed at different times. Corresponding rows of the SLM(s)s are associated with different reset groups.

Abstract: A display system with a pointer that is not restricted by wires or sensors. The display uses a spatial light modulator (14) for projecting an image on the screen (20). During a time period when all of the cells of the modulator (14) are in the same state, a cursor projected onto the screen by the pointer is reimaged from the screen to a detector (26), which translates the cursor image into signals for a central processing unit (38). The central processing unit (38) then directs the system as to what tasks are being dictated by the cursor.

Abstract: A method of using a display system having a spatial light modulator (14) to display holographic images. The spatial light modulator (14) generates images that represent vertical strips of a hologram. These images are de-magnified by a three-dimensional optics unit (18), in the horizontal direction so as to form image strips. A scanning mirror (45) scans the image strips in a series across an image plane at a rate sufficiently fast that the viewer perceives a composite hologram comprised of these image strips.

Abstract: An improved hinge (12) for a micro-mechanical device (10). The hinge is fabricated from alternating layers (12a, 12b) of different materials. A first material is selected on the basis of its amenability to fabrication processes and a second material is chosen for its strength, or some other desired characteristic, relative to the first material.

Abstract: A color wheel assembly (15, 15a, 15b) for use in a display system (10) that uses a beam of source illumination to generate images with a display device. The color wheel (15) is moveable in and out of the path of the source beam so as to provide varying levels of brightness or color saturation. The color wheel (15') may also have concentric rings (41, 43) for varying saturation or color balance.

Abstract: An improved support post (16, 23, 25) for micro-mechanical devices (10). A via (34a) that defines the outer surface of the support post (16) is etched into a spacer layer (34). An oxide layer (41) is conformally deposited over the spacer layer (34) and into the via (34a), and then etched back to the top surface of the spacer layer (34), leaving a sidewall ring (23a) on the inner surface of the via (34a). Next, a metal layer (61) is deposited over the spacer layer (34) and into the via (34a) so as to cover the sidewall ring (23a). This metal layer (61) is then etched to form a support post stem (23) inside the via (34a). The spacer layer (34) is removed, leaving the support post stem (23) and a sidewall ring (23a) around the stem (23).

Abstract: An optical guide (10, 40, 50, 60) for horizontally aligning two vertically stacked images generated by one or two SLMs. The optical guide has a channel separator (10a) that directs both images along two different paths. A pair of aligning reflectors (10b and 10c) on each path vertically shift the images with respect to each other so that at least part of the images on the first path are aligned side-by-side with at least part of the images on the second path. The channel separator (10a) then re-directs the images to the image plane 15. Along both paths, at least two of the reflecting surfaces of channel separator (10a) or aligning reflectors (10b and 10c) are optically powered so as to change the width or height of the images.