Autostereoscopic image display adjustable for observer location and distance

Apparatus for the display of autostereoscopic images, comprising:

• means for detecting the location of an observer with respect to an image forming region;
• optical means for providing, for a first and a second eye of the observer, respective regions of concentration of light, the light of a first region of concentration providing, in use, an image of a first single perspective of a scene at said image forming region, said first region of concentration being adjacent to a corresponding first region substantially void of light from said first perspective image, and the light of a second region of concentration providing, in use, an image of a second single perspective of said scene at said image forming region, said second region of concentration being adjacent to a corresponding second region substantially void of light from said second perspective image;
• means for providing an output signal from the detecting means indicative of the observer's location;
• and
• control means responsive, in use, to said output signal and causing the locations of said first and second regions of concentration of light to substantially track and be co-located respectively with the first and the second eyes of the observer, and the locations of said first and second void regions to be co-located respectively with the second and the first eyes of the observer,
• wherein the detection means is arranged to measure a viewing distance of the observer, and the control means is arranged to control the distance of the regions of concentration of light from said image forming region to correspond, in use, to said measured distance and to leave the scale of the image provided at said image forming region substantially unaltered by said control of distance.

Apparatus for detecting the location of a marker borne by an observer, comprising:

• a source of infrared radiation;
• imaging means for imaging the space illuminated by said source and for providing image data;
• and
• locating means for locating, in use, within the image data of said space, the image of the marker and deriving positional data corresponding to the located marker image,
• wherein said locating means is arranged to acquire image data from the imaging means periodically and said source is arranged to switch synchronously with the period so that, in use, an output signal is derived by said locating means from the difference between image data acquired during consecutive periods.

A method for displaying autostereoscopic images, comprising the steps of:

• locating a viewing location of an observer and outputting a location signal indicative of the viewing location;
• providing for a first and a second eye of the observer respective regions of concentration of light, the light of a first region of concentration providing an image of a first single perspective of a scene from an image forming region, said first region of concentration being adjacent to a corresponding first region substantially void of light from said first perspective image, and the light of a second region of concentration providing an image of a second single perspective of said scene from said image forming region, said second region of concentration being adjacent to a corresponding second region substantially void of light from said second perspective image;
• and
• controlling, in response to the location signal, the locations of said first and second regions of concentration of light to substantially track and be co-located respectively with the first and the second eye of the observer, and controlling the locations of said first and second void regions to be co-located respectively with the second and the first eye of the observer,
• the providing step including the substeps of:
• providing at least one lenticular screen having a substantially evenly spaced plurality of juxtaposed lens elements constituting a first periodic structure, and
• providing a second periodic structure for cooperating with the lenticular screen to supply at least one of said first and second regions of concentration of light and said corresponding void regions, and
• the control steps including the substep of:
• moving said lenticular screen in a first direction relative to said second periodic structure, thereby positioning the supplied region of concentration of light to provide tracking.

A method for displaying autostereoscopic images comprising the steps of:

• locating a viewing location of an observer and providing an output signal indicative of the viewing location;
• providing for a first and a second eye of the observer respective regions of concentration of light, the light of a first region of concentration providing an image of a first single perspective of a scene from an image forming region, said first region of concentration being adjacent to a corresponding first region substantially void of light from said first perspective image, and the light of a second region of concentration providing an image of a second single perspective of said scene from said image forming region, said second region of concentration being adjacent to a corresponding second region substantially void of light from said second perspective image;
• and
• causing, responsive to said output signal, the locations of said first and second regions of concentration of light to substantially track and be co-located respectively with the first and the second eye of the observer, and causing the locations of said first and second void regions to be co-located respectively with the second and the first eye of the observer, wherein said locating step includes measuring a first distance to the observer's viewing location;
• and said causing step includes controlling a second distance to the regions of concentration of light to correspond to said first distance;
• and leaving the scale of the scene provided at said image forming region substantially unaltered by said control of distance.

A method for locating the head of an observer, comprising the steps of:

• illuminating a space with a source of radiation;
• periodically acquiring an image of said space;
• locating, within said image, the image of said head and deriving positional data corresponding to the located image;
• and
• switching said source synchronously with the acquiring periods and deriving an output signal from a difference between the image data acquired during consecutive periods.

A display apparatus comprising:

• an image source extending in at least a first direction, said image source providing a plurality of first and second light components alternately provided along the first direction;
• and
• a first optical structure having a plurality of first periodic optical elements, each optical element extending in a second direction substantially orthogonal to the first direction, said first optical structure being displaceable relative to said image source in a direction orthogonal to the second direction, the plurality of optical elements operating to direct the first light components to a first imaging location and the second light components to a second imaging location;
• observer location detecting means for detecting a location of an observer;
• and
• movement control means, operatively connected to said observer location detecting means, for displacing said first optical structure relative to said image source such that the first and second imaging locations follow and are co-located with respective eyes of the observer.