Television – Stereoscopic – Stereoscopic display device
Reexamination Certificate
1997-01-02
2001-08-14
Kelley, Chris (Department: 2613)
Television
Stereoscopic
Stereoscopic display device
C313S495000, C313S409000, C313S422000, C313S446000, C345S182000, C359S458000, C359S462000
Reexamination Certificate
active
06275254
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an auto-stereoscopic display system and auto-stereoscopic display device for inclusion in such a system.
2. Background Description
Three dimensional or stereoscopic images may be produced via holographic, volumetric, or multi-view techniques. A conventional multi-view technique involves viewing a frame sequential pair of images with specially adapted glasses. Specifically, a display device present alternate left and right views to the observer on a frame sequential basis. The glasses worn by the observer effectively route the views to each eye. Shutters or polarisers in the glasses are synchronised to the frame rate to control the routing. To prevent flicker, the frame rate must be doubled or the resolution halved with respect to the two dimensional equivalent image. A disadvantage with such as system is that the two images produce only a limited “look around” capability. Furthermore, glasses have to be worn to produce any effect.
Another conventional multi-view technique involves a barrier auto-stereoscopic display system. In some examples of such a system, a stereo pair of images is sliced into vertical strips. The strips of each image of the pair are meshed together on the display screen. A physical barrier is placed in front of the display screen. Small viewing zones are formed in the barrier so that the left eye can see only strips of the first image of the pair and the right eye can see only strips of the second image of the pair. The observer re-constructs the full image in three dimensions. A disadvantage with this arrangement is that the viewing zone is very narrow. Outside the zone, the observer sees multiple images or a stereo inversion. Furthermore, there is no “look around” effect. In a modification to the physical barrier system, the barrier is replaced by a lenticular lens screen having an array of vertical cylindrical lenses each corresponding to a different pair of left and right view strips.
The lenticular screen approach can be enhanced by assigning further image strips to each lens. For example, if each lens corresponds to four views (from four cameras instead of two) then repeating double viewing zones are generated instead of the repeating single viewing zone associated with the basic method described earlier. If the observer moves to the left of the display screen, a new image, to left of the previous image, is observed. The number of reverse stereo zones is reduced. Specifically, reverse stereo zones are produced only at the point where multiple zones repeat. The latitude of head movement is improved with increasing number of views. Each different view can be employed to simulate “look around” effects. A disadvantage with four view systems is that as the observer moves from the first view to the second view, the spatial resolution of the system causes a jump in continuity. In general, experiment suggests that 16 views are sufficient to produce satisfactory three dimensional viewing.
In an example of a conventional multi-view system, there is provided a 16 view time-multiplexed cathode ray tube (CRT) display comprising a slit shutter disposed at a distance of around 30 cm in front of the screen. A disadvantage with this time division arrangement is that the display system is required to operate at high CRT scan frequencies (greater than 150 kHz), very high EHT voltages (greater than 30 kV), and very fast phosphors. Furthermore, the spacing between the CRT and the shutter produces a cumbersome construction.
It is desirable in a multi-view lenticular system to display each view in relatively narrow stripes. The thickness of the stripe is dependent on the spot size of the display. Liquid crystal display (LCD) panels have a relatively large spot size. Relatively small spot sizes can be achieved in conventional CRTs. However, to achieve such spot sizes in a CRT, relatively high EHT voltages, fast video amplifiers, and fast phosphors are required, leading to added circuit complexity, power consumption, and manufacturing cost. Furthermore, for optimum results, the lenticular screen is preferably located close to a flat image source. The thickness and curvature of many conventional CRTs therefore renders them unsuitable.
It would be desirable to provide a new stereoscopic display technology in which the aforementioned problems associated with conventional stereoscopic display technologies such as LCD and CRT are solved.
SUMMARY OF THE INVENTION
In accordance with the present invention there is now provided an auto-stereoscopic display device comprising: a plane viewing screen; a plane cathode; a plane permanent magnet; a two dimensional array of rows and columns of channels extending between opposite poles of the magnet for receiving electrons from the cathode; a phosphor layer disposed between the screen and the magnet and having a plurality of pixels each corresponding to a different channel; grid electrode means disposed between the cathode and the magnet for selectively controlling flow of electrons from the cathode through each channel to the corresponding pixel in response to input video data; deflection anode means for sequentially deflecting, orthogonally to the columns, each electron beam to different parts of the corresponding pixel in response to an input video clock signal; and a lenticular lens array disposed between the phosphor layer and the screen and having a plurality of cylindrical lenses each corresponding to a different column of pixels.
The phosphor coating may be deposited on the side of the lens array remote from the screen. Alternatively, the phosphor coating may be deposited on a barrier disposed between the deflection anodes and the lens array. The barrier preferably comprises a glass layer secured to the lens array.
In preferred embodiments of the present invention, there is provided interpolating means for interpolating between different views in the video input data to generate one or more additional views.
It will be appreciated that the present invention extends to an auto-stereoscopic display system comprising a display device as hereinbefore described, a video data source for generating the input video data and the video clock signal, and a communication link for transferring the input video data and the video clock signal from the video data source to the display device.
Preferably, the communication link comprises compression means for compressing the input video data for transfer from the video source to the display device.
REFERENCES:
patent: 4618801 (1986-10-01), Kakino
patent: 4959641 (1990-09-01), Bass et al.
patent: 4973888 (1990-11-01), Morimoto et al.
patent: 5317393 (1994-05-01), Lee
patent: 5495576 (1996-02-01), Ritchey
patent: 5565742 (1996-10-01), Shichao et al.
patent: 5633650 (1997-05-01), Kishino et al.
patent: 5721561 (1998-02-01), Kishino et al.
patent: 5726800 (1998-03-01), Ezra et al.
patent: 5739634 (1998-04-01), Kinoshita et al.
patent: 2 183 900 (1987-06-01), None
patent: 2 271 464 (1994-04-01), None
Beeteson John
Knox Andrew
An Shawn S.
Dillon Andrew
Grosser George E.
International Business Machines - Corporation
Kelley Chris
LandOfFree
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