Abstract:
Disclosed is an imaging directional backlight including an array of light sources, and a control system arranged to provide variable distribution of luminous fluxes, scaled inversely by the width associated with the respective light sources in the lateral direction, across the array of light sources. The luminous intensity distribution of output optical windows may be controlled to provide desirable luminance distributions in the window plane of an autostereoscopic display, a directional display operating in wide angle 2D mode, privacy mode and low power consumption mode. Image quality may be improved and power consumption reduced.
Abstract:
Disclosed is an imaging directional backlight that cooperates with a spatial light modulator to direct light into a first viewing window for one set of image pixels and into a second viewing window for a second set of image pixels. The waveguide may comprise a stepped structure, where the steps further comprise extraction features hidden to guided light, propagating in a first forward direction. Returning light propagating in a second backward direction may be refracted, diffracted, or reflected by the features to provide discrete illumination beams exiting from the top surface of the waveguide. Viewing windows are formed through imaging individual light sources and hence defines the relative positions of system elements and ray paths. Such an apparatus may be used to achieve an autostereoscopic display with a flat structure, not requiring fast response speed spatial light modulators.
Abstract:
Disclosed is an autostereoscopic display apparatus comprising a light guiding valve apparatus including an imaging directional backlight, an illuminator array and an observer tracking system arranged to achieve control of an array of illuminators which may provide a directional display to an observer over a wide lateral and longitudinal viewing range with low flicker.
Abstract:
An imaging directional backlight apparatus including a waveguide, a light source array, for providing large area directed illumination from localized light sources. The waveguide may include a stepped structure, in which the steps may further include extraction features optically hidden to guided light, propagating in a first forward direction. Returning light propagating in a second backward direction may be refracted, diffracted, or reflected by the features to provide discrete illumination beams exiting from the top surface of the waveguide. Viewing windows are formed through imaging individual light sources and hence defines the relative positions of system elements and ray paths. The uncorrected system creates non-illuminated void portions when viewed off-axis preventing uniform wide angle 2D illumination modes. The system may be corrected to remove this non uniformity at wide angles through the introduction of additional sources away from the system's object plane, additional imaging surfaces, and/or by altering ray paths.
Abstract:
An imaging directional backlight apparatus including a waveguide, a light source array, for providing large area directed illumination from localized light sources. The waveguide may include a stepped structure, in which the steps may further include extraction features optically hidden to guided light, propagating in a first forward direction. Returning light propagating in a second backward direction may be refracted, diffracted, or reflected by the features to provide discrete illumination beams exiting from the top surface of the waveguide. In operation, luminance streaks and bright illumination regions may be formed due to undesirable imaging characteristics from the structure of the Fresnel mirror. Fresnel mirror draft facets and reflective facet microstructures are provided that achieve reduction of visibility of light streaks and bright illumination regions.
Abstract:
Disclosed is an imaging directional backlight apparatus comprising a waveguide, a light source array, and a further optical element for providing large area directed illumination from localized light sources. The imaging directional backlight may comprise a stepped waveguide that may include a stepped structure, in which the steps may further include extraction features optically hidden to guided light, propagating in a first forward direction. Returning light propagating in a second backward direction may be refracted, diffracted, or reflected by the features to provide discrete illumination beams exiting from the top surface of the waveguide. Viewing windows are formed through imaging individual light sources. The further optical element may comprise a superlens comprising first and second aligned lens arrays that may be arranged to modify the output viewing windows to achieve enhanced window imaging from the directional backlight.
Abstract:
In telecommunication video calling and videoconferencing systems, it is strongly desirable for remote observers to interact with natural gaze cues. In natural gaze interaction, the camera for a source observer appears to be co-located in the eye region of a destination observer image and vice versa. The appearance of camera co-location is achieved for stereoscopic camera pair that are placed either side of an autostereoscopic 3D display. Such cameras typically provide stereoscopic images that have disparity distributions that provide unnatural perceived head roundness. The present embodiments achieve perceived head roundness that is closer to that expected in natural face to face interaction by modification of perceived local depth in detected regions of the head.
Abstract:
Disclosed is a light guiding valve apparatus including at least one transparent stepped waveguide optical valve for providing large area collimated illumination from localized light sources, and at least one further illumination source. A stepped waveguide may be a stepped structure, where the steps include extraction features hidden to guided light, propagating in a first forward direction. Returning light propagating in a second backward direction may be refracted, diffracted, or reflected by the features to provide discrete illumination beams exiting from the top surface of the waveguide. Such controlled illumination may provide for efficient, multi-user autostereoscopic displays as well as improved 2D display functionality. Light from a separate illumination source may pass through the transparent stepped waveguide optical valve to provide at least one further additional illumination function.
Abstract:
Teleconferencing is performed between two telecommunication devices having a display device and a stereoscopic pair of cameras positioned outside opposed sides of the display device at the same level partway along those sides. The separation between the centers of the cameras is in a range having a lower limit of 60 mm and an upper limit of 110 mm to improve the perceived roundness in a displayed stereoscopic image of a head. In captured stereo images that are video images, a head is segmented and the segmented backgrounds are replaced by replacement images that have a lower degree of perceived stereoscopic depth to compensate for non-linear depth perception in the displayed stereo images. Images are shifted vertically to position an eye-line of a detected face at the level of the stereoscopic pair of cameras of the telecommunication device where the images are displayed, improving the naturalness of the displayed image.
Abstract:
Disclosed is an imaging directional backlight apparatus for providing large area uniform directed illumination from localized light sources. Within an exemplary optical valve system, a waveguide comprises a stepped structure, where the steps comprise extraction features hidden to guided light, propagating in a first forward direction. Returning light propagating in a second backward direction may be refracted, diffracted, or reflected by the features to provide discrete illumination beams exiting from the top surface of the waveguide. Such controlled illumination may provide for efficient, multi-user autostereoscopic displays as well as improved 2D display functionality. Illumination uniformity is provided by the positioning, packaging, and optically modifying of individual input sources. The latter employs non-imaging and refractive optics.