Abstract:
Apparatus and method for the display of autostereoscopic images, in which two or more perspective views are generated by a single transmissive display screen, is provided. A structured light source behind the screen directs light through different sets of display elements to correspondingly different viewing zones. In certain embodiments, the structured source comprises a patterned mask which prevents light from passing through a particular set of elements and reaching the wrong zone. The pattern of the mask may be programmed. Observer co-ordinate data permits the correct viewing zone to be co-located with each of the observer's corresponding eyes. A tapered lenticular structure can provide the means for adapting to changes in the observer's distance from the display. In further embodiments a holographic optical element (HOE) may be used instead of an array of conventional lens elements. The HOE typically incorporates the function of providing in conjunction with a suitably located light source the viewing zones required for respective sets of display elements. The display may also be used to provide conventional two-dimensional images at the display screen's full resolution.
Abstract:
Apparatus for producing a record of an object field in which substantially perspective change in one direction only is recorded. The apparatus comprises elongate aperture means (35) and an array of lens elements (34) which extends in two dimensions and is disposed in an image field. Each lens element (34) is convergent in all planes orthogonal to the array. Recording means are so arranged that each lens element (34) forms an image thereon. Each recorded image (36) is derived from rays from a range of perspectives of the object field in one direction and a substantially smaller range in an orthogonal direction and each recorded image (36) is distinct from each other recorded image. Reproduction apparatus allows an autostereoscopic image to be formed on conventional lenticular material from an intermediate record produced by the recording apparatus.
Abstract:
Stereoscopic apparatus is described in which the spectral components of each perspective of the image are supplied in sequence and in such a way that whilst the left eye is receiving one spectral component of one of the perspectives, the right eye receives the other spectral component of the other perspective, and in alternating periods the left eye receives the other spectral component of its perspective whilst the right eye receives the first spectral component of its perspective. Various means for producing the image and for viewing the two perspectives are illustrated.
Abstract:
Apparatus such as a camera for producing autostereoscopic images from convergent optical assemblies and imaging devices including (in a preferred embodiment of FIG. 11) curved reflecting surfaces. Light from the object field represented by rays R1, R2 and R3 enters the camera through a horizontally long but vertically narrow slot 210. The light is split into reflected and transmitted components by semi-transparent mirror 211. Two horizontal apertures 212 and 213, one in each component beam, prevent unwanted vignetting. A plane mirror 214 folds the reflected component from mirror 211 so that it is approximately parallel to the transmitted component. A curved reflector assembly 215 which typically comprises a series of curved reflectors side by side horizontally creates one or more intermediate images of the object field at a retroreflective screen 216, which is arranged to move in its own plane during exposure of the film and receives both the transmitted and reflected components of light. Following the return of each ray by the retro-reflector substantially down its original path, the two component rays are recombined by semi-transmitting mirror 211 and pass through the camera's shutter mechanism shown here to consist of two moving sheets 217. Three mirrors 218, 219 and 220 fold the optical path to the lenticular screen and emulsion 221. Imaging of the object field is achieved by providing mirrors 219 and 220 with the necessary curvature. The optimum viewing distance of the final picture may be independently defined by use of a weak field lens 222.
Abstract:
Apparatus for producing a record of an object field in which substantially perspective change in one direction only is recorded. The apparatus comprises elongate aperture means (35) and an array of lens elements (34) which extends in two dimensions and is disposed in an image field. Each lens element (34) is convergent in all planes orthogonal to the array. Recording means are so arranged that each lens element (34) forms an image thereon. Each recorded image (36) is derived from rays from a range of perspectives of the object field in one direction and a substantially smaller range in an orthogonal direction and each recorded image (36) is distinct from each other recorded image. Reproduction apparatus allows an autostereoscopic image to be formed on conventional lenticular material from an intermediate record produced by the recording apparatus.
Abstract:
Stereoscopic apparatus is described in which the spectral components of each perspective of the image are supplied in sequence and in such a way that while the left eye is receiving one spectral component of one of the perspectives, the right eye receives the other spectral component of the other perspective, and in alternating periods the left eye receives the other spectral component of its perspective while the right eye receives the first spectral component of its perspective. Various means for producing the image and for viewing the two perspectives are illustrated.
Abstract:
A method and apparatus for the production of an autostereoscopic and/or animated image on a lenticular screen is provided. In order to achieve the required accuracy for a good lenticular image, a detector is used to measure the location of an edge of the image bearing substrate and image data is positioned relative to this edge. The substrate may be a conventional print medium for subsequent attachment to the lenticular screen or the screen itself. As an alternative to the edge of the substrate, the lens elements of the screen can provide the frame of reference for accurate registration of the image. This is achieved by viewing a defined reference grid through the lenticular screen and converting the observed Moiré pattern into data suitable for positioning the elements of the required image, thereby accommodating dimensional variations within the screen.
Abstract:
A stereoscopic image acquisition and display system and associated method, suitable for effective eye-hand co-ordination during videoscopic surgery, is provided. The problems of previous three-dimensional acquisition and display systems are addressed by ensuring that the convergence angle for image acquisition lies within the range of 3 to 16 degrees and that the observer's visual convergence is set within similar limits. Simultaneous display of left and right eye images avoids the problems of field sequential displays. By providing the observer with a displayed image which is sufficiently bright and ensuring that the binocular disparity between corresponding points in the left and right eye images is correct, the system allows the observer to fuse a pair of stereo-images, without causing conflict between visual accommodation and convergence. The location of the displayed image may be adjusted.
Abstract:
A stereo-endoscope, by which two perspective views of an objective field are viewed, is provided. A divergent optical arrangement, positioned between the object field and two objective lenses, each of which forms a respective image of the object field, reduces the disparity between corresponding points in the two image fields, where such disparity is caused by distortion of the image formed.
Abstract:
Optical distance measuring apparatus has a focusing lens (16) directing light reflected from a target toward a detector (18), The lens has discrete or continuous zones each associated with a target distance. The area of the lens zones increases with an increase in associated target distance so as to compensate for a reduction in intensity according to the inverse square law.