Abstract: A lens shift mechanism 32 of the projection-type image display device 10 includes a horizontal movable base 60 for horizontally shifting a projection lens 31, a vertical movable base 70 for vertically shifting the projection lens 31, and a horizontal drive actuator 61 and a vertical drive actuator 71 for driving these bases 60, 70. Driving forces of these actuators 61, 71 are transmitted via respective lead screws 671 (751) and a pair of lead nuts 672, 672b (752, 752b) meshing with the lead screws to shift the bases 60, 70. A pair of lead nuts are installed with elastic bodies 672c (752c) applying a pressure such that the pair of lead nuts recede from or approach each other in the axial direction of the lead screw. In this configuration, a delay in the shift operation is removed by reducing a backlash in the lens movement.

Abstract: Methods and apparatus are provided for reorienting control moment gyros (CMGs) to compensate for CMG failure or change in spacecraft (S/C) mass properties or mission. An improved CMG comprises a drive means for rotating the CMG around an axis not parallel to the CMG gimbal axis. Releasable clamps lock the CMG to the spacecraft except during CMG array reorientation. CMGs arrays are combined with attitude sensors, a command module, memory for storing data and programs, CMG drivers and sensors (preferably for each CMG axis), and a controller coupling these elements. The method comprises determining whether a CMG has failed or the S/C properties or mission changed, identifying the working CMGs of the array, determining a new array reorientation for improved spacecraft control, unlocking, reorienting and relocking the CMGs in the array and updating the S/C control parameters for the new array orientation.

Abstract: An improved target sighting device of the type particularly suited for use on moving vehicles, such as military aircraft, and in which a vertically-disposed C-shaped elevation gimbal is supported for rotary movement about an elevation axis at the center of the gimbal to enable a vertically extending mirror on the gimbal to be aimed toward a target along a line of sight at one side of the gimbal, for reflection of target information along such axis and through the open end of the gimbal to a fixed optical pickup assembly. Improvement resides in the support of the open end of the gimbal by a ring bearing encircled by an annular flex pivot assembly that limits the extent of rotary aim-influencing vibration that can be transmitted from the exterior of the device to the gimbal and mirror circumferentially through the ring bearing by friction.