Abstract: A light valve projector of the Schlieren dark field type is provided with an improved input bar plate configuration which achieves greater light efficiencies. The improved input bar plate has orthogonally related rows and columns of slots in which the row slots are spaced between the column slots. Alternating rows of lenslets of a first array divide columns of lenslets of a second array. Light filtering is provided such that one color passes through the row slots and another color passes through the column slots. The output bar plate has a configuration which is complementary to the input bar plate.

Abstract: A multiple light valve (MLV) projector apparatus for producing a color display includes two separate light valves of the Schlieren dark field type. One of the light valves produces a first primary color, for example green, and the other light valve produces two other primary colors, for example red and blue. In such an apparatus the output brightness is usually limited by the red light output. An improved input (and complementary output) mask is described which optimizes the transmission of the first, second and third diffraction orders through the slots in the portion of the input mask which transmits red light. Such an optimization provides a substantial increase in red light output compared to a conventional input mask.

Abstract: Improved masking of light valve spill light is disclosed for Schlieren dark field light valves. The mask is deposited on the interior or exterior of the output window (58) and comprises an opaque area (90) which surrounds a transparent window area (91). The mask is characterized by a zone (92) of graduated density from transparent to opaque. The effect of the graduated density zone is to eliminate spurious light diffracted by the edges of the mask and significantly improves the performance of the light valve.

Abstract: Improved signal modulating circuits for a light valve projector are disclosed which are capable of increasing the magenta efficiency of the projector. The projector has an input bar plate having slots, a deformable light modulating medium and an output bar plate having slots. The control circuits generate a first control signal for red and a second control signal for blue. The light modulating medium is modulated in accordance with the red and blue control signals. The control circuits enhance the magenta modulation of the light modulating medium by generating a third control signal for magenta.A first circuit provides a magenta control signal whenever there is a magenta component which is the result of simultaneous inputs from the red and blue signals. A separate signal level for magenta is derived from the red and blue signals and a separate magenta carrier frequency is used which will cause magenta light to pass through slots in the output bar plate.

Abstract: A high efficiency light collection system for a projector such as a light valve projector provides constant tangential magnification for all zones so that the images of the source just fills the pupil of the projection system thereby giving the best source utilization in all zones. The light collection system comprises a reflector (60) behind the source and a correcting refractor (61) in front of the source. The preferred embodiment uses an aconic reflector having continuously changing zonal focus with a single asphere corrector lens that has exactly compensating zonal focus characteristics. It is also possible to use a conic reflector, but this requires two asphere corrector lenses in order to provide the constant tangential magnification characteristics.

Abstract: A light valve projection system is disclosed in which information is impressed on a light modulating fluid overlying a disk wherein incident light is modulated by the information and projected onto a viewing surface. The fluid layer includes a raster area within which the information is written by the deposition of electric charge along scanning lines so as to form orthogonally related diffraction gratings which are parallel to a pair of coordinate axes in the plane of the disk. The diffraction gratings are composed of one set of gratings parallel to the scanning lines which contain green color information, and two sets of diffraction gratings orthogonal to the scanning lines containing red and blue color information. Improved green channel vertical resolution is obtained by axis dwell modulation of the scanning lines to better confine the detail modulation to the raster line axis.

Abstract: A light valve projection system is disclosed in which information is impressed on a light modulating fluid overlying a disk wherein incident light is modulated by the information and projected onto a viewing surface. The fluid layer includes a raster area within which the information is written by the deposition of electric charge along scanning lines so as to form orthogonally related diffraction gratings which are parallel to a pair of coordinate axes in the plane of the disk. The diffraction gratings are composed of one set of gratings parallel to the scanning lines which contain green color information, and two sets of diffraction gratings orthogonal to the scanning lines containing red and blue color information. Improved green channel vertical resolution is obtained by axis dwell modulation of the scanning lines to better confine the detail modulation to the raster line axis.

Abstract: A light collection system for projectors, such as light valve projectors, has a compound reflector associated with an arc lamp. The compound reflector includes an ellipsoidal reflector positioned to collect a portion of the light from the arc lamp and reflect a direct image of the light in a beam to an image forming plane of the projector and a spherical reflector positioned to collect another portion of the light from the arc lamp and reflect it back through the gap of the arc lamp to the ellipsoidal reflector to be reflected as a secondary image of the light from the lamp in the beam. The ellipsoidal and spherical reflectors are formed as full, uninterrupted surfaces of revolution. To provide uniform light distribution, the beam is directed through a pair of spaced lens plates, each having corresponding arrays, in rows and columns, of rectangular lenticules.

Abstract: A light valve projection system in which information is impressed on a light modulating fluid overlaying a rotatable disk wherein incident light is modulated by said information and projected onto a viewing surface, said fluid including a raster upon which said information is written by the deposition of electric charge along scanning lines so as to form orthogonally related diffraction gratings which are parallel to a pair of coordinate axes in the plane of said disk. The raster is positioned on said disk offset from said coordinate axes so that movement of said fluid responsive to disk rotation is along paths that intersect said diffraction gratings, which is found to provide a more uniform fluid thickness and light transmission efficiency within the raster and to improve certain aspects of the projected information.