Abstract: An image projection system includes an image generator, a screen and a focus and aim component. The focus and aim component receives modulated light from the image generator and focuses and deflects the light as a function of a position on the screen. The component consists of an array of lenslets with wedge. The wedge or prism refracts the light and the lens focuses the light. As a result, the optics are selectively tailored to provide a clear image over the entire field of view, even in systems compact in depth that would otherwise rely on a short focal length lens. Acute incidence angles at the periphery of the screen are handled by TIR Fresnel lens elements or by diffractive elements. The focus and aim capability is alternatively provided by holographic elements in a holographic array.

Abstract: An infrared radiation detector includes a bolometer or micro-cantilever detector device which functions as a null detector in conjunction with electronic circuitry. The electronic circuitry senses a change in an output signal of the detector as the detector responds to infrared radiation incident upon the detector and provides a signal to a control element which provides a stimulus to the detector device to maintain the detector output signal at the same level. The element may be a piezoelectric element, a heater or a pair of electrodes and the corresponding stimulus may be stress, heat, or electrostatic change. The stimulus compensates for the effect of the infrared radiation and maintains the chosen detector output level at the same level. The nulling circuitry improves the linearity and dynamic range of the detector device.

Abstract: Recovery from a record of data recorded in an elongated information track, comprising depressed areas of a given width, a given depth and variable length, alternating along the length of the track with relatively non-depressed areas, is effected by an optical playback system. The playback system employs means for focusing light from a laser source on the information track as a light spot having a diameter which is diffraction limited. The focusing system includes an additional light source (e.g., laser) which impinges on the surface of the record as a circular spot which illuminates a plurality of elongated tracks. The circular spot is imaged by a lens system on a detector plane which is positioned at a plane which is conjugate to the record surface.

Abstract: Recovery from a record of data recorded in an elongated information track, comprising undulations representative of the data is effected by an optical playback system. In the system, the data is recorded within two substantially different frequency bands. The optical playback system has a dual response characteristic to provide improved response at the two different frequency bands. A modifying means interposed in the light beam path shapes the light beam to effect this dual response characteristic (i.e., two different bandwidth responses).

Abstract: A redundant Fraunhofer or Fresnel hologram is recorded by interfering a temporal-information beam with a reference beam of mutually coherent light. The temporal-information beam is intensity-modulated with each of a series of samples of the temporal information signal. The relative phase difference between the two interfering beams is selectively determined for each sample of the series and the effective value of the angular displacement between the two interfering beams is changed for each successive sample of the series. The hologram can be recorded directly from an electronic signal, such as television, without the need for a coherently illuminated object, or an intermediate imaging step, such as transcribing from television to film.