Autostereoscopic screen and method for the simultaneous reproduction of more than two different pictures

Patent metadata

Field	Value
Publication number	US-9883171-B2
Application number	US-201214420662-A
Country	US
Kind code	B2
Filing date	Oct 4, 2012
Priority date	Aug 10, 2012
Publication date	Jan 30, 2018
Grant date	Jan 30, 2018

Abstract

An autostereoscopic screen for the simultaneous reproduction of more than two different pictures, including a pixel matrix with a multitude of pixels, an optical element arranged on front of or behind the pixel matrix, and a control unit for activating the pixel matrix and the optical element. The optical element forms an optical grid with a family of strip-like structures which run next to one another, wherein a period length of the optical grid is changeable by way of activating the optical element. Thereby, for a change of a viewing distance (L n , L; L′) the control unit is configured to increase or reduce the period length and to simultaneously change a distribution of picture information onto the pixel matrix. The disclosure further relates to a corresponding method for the simultaneous reproduction of more than two different pictures.

First claim

The invention claimed is:

1. An autostereoscopic screen for the simultaneous reproduction of more than two different pictures, comprising a pixel matrix with a multitude of pixels, an optical element arranged in front of or behind the pixel matrix and a control unit for activating the pixel matrix,
wherein the pixels of the pixel matrix are arranged in a multitude of parallel strips of pixels, the strips being vertical or inclined with respect to the vertical,
wherein the optical element forms an optical grid with a family of strip-like structures running equidistantly next to one another and parallel to the strips, said grid in each case setting a defined propagation direction for the light departing from or transmitted by the pixels,
wherein the control unit is configured to activate the pixel matrix in dependence on picture information of a plurality of stereoscopic half-pictures, such that each of these half-pictures is reproduced in each case on one of a corresponding number of subsets of pixels wherein each of these subsets is formed by a family of bands of pixels which are formed in each case by one or more of the strips, wherein the bands of the different subsets cyclically alternate in the horizontal direction, so that each of the stereoscopic half-pictures is visible at a viewing distance (L n , L; L′) in front of the screen, in each case from one of several laterally offset viewing zones, wherein a period length of the optical grid which is defined by a lateral offset of adjacent, strip-like structures, is changeable by way of activation of the optical element, wherein the optical element is activatable by the control unit, and the control unit is configured to carry out the following steps for a change of the viewing distance:
enlarging or reducing the period length of the optical grid and
redefining the mentioned subsets in a manner such that a width or an average width of the bands of pixels which form the subsets is changed by at least a width of one of the mentioned strips,

so that a relative change of a lateral offset of the adjacent viewing zones is smaller than a relative change of the viewing distance, wherein the control unit is configured to increase the width of the bands forming the subsets for reducing the viewing distance and to reduce the width of the bands for increasing the viewing distance.

2. The autostereoscopic screen according to claim 1 , wherein the control unit is configured, for the change of the viewing distance, to additionally increase or reduce the number of subsets and accordingly the plurality of reproduced stereoscopic half-pictures.

3. The autostereoscopic screen according to claim 1 , wherein the control unit is configured to thereby define the subsets in each case such that all or a majority of the bands are formed in each case by an integer number of the strips of pixels which is equal for these bands, wherein the control unit is further configured to increase or to reduce this integer number for the change of the viewing distance and thereby to change the period length of the optical grid by a factor which corresponds to a ratio of a product of the number of subsets and the integer number after the change, to the product of the number of subsets and the integer number before the change.

4. The autostereoscopic screen according to claim 3 , wherein the control unit is configured to thereby define the subsets in each case such that for a number of bands of pixels which corresponds to the number of subsets, there is on average less than one strip of pixels which is assigned to none of the bands or contributes to a width of one of the bands which differs from a width of the majority of the bands.

5. The autostereoscopic screen according to claim 3 , wherein the optical element for activation comprises a family of electrodes running parallel to the strips, wherein the control unit is configured to activate the electrodes in each case with electrical command variables varying periodically from the left to the right, so that in each case a number of electrodes which corresponds to the product of the number of subsets and the integer number, forms a period.

6. The autostereoscopic screen according to claim 5 , wherein one of the electrodes is assigned to each of the strips of pixels, wherein a lateral offset of adjacent electrodes is smaller than a lateral offset (d) of adjacent strips of pixels by a factor (L n /L n +a), wherein a indicates a distance between the pixel matrix and the optical grid, and L n a nominal viewing distance of the autostereoscopic screen.

7. The autostereoscopic screen according to claim 1 , wherein the optical element is given by a liquid-crystal structure.

8. The autostereoscopic screen according to claim 1 , wherein the optical grid is a lenticular lens, and the strip-like structures form cylindrical-lens-like lenses.

9. The autostereoscopic screen according to claim 1 , wherein the optical element is a liquid-crystal lens system.

10. Autostereoscopic screen according to claim 1 , wherein it comprises a device for detecting a distance of a viewer head or eye pair, to the screen, wherein the control unit is configured to activate the pixel matrix and the optical element such that the viewing distance corresponds to the detected distance, and to carry out the steps when a viewing distance exceeds or falls short of a threshold value.

11. The autostereoscopic screen according to claim 1 , wherein the control unit is configured to fix the viewing distance in dependence on a manual input or an input signal and to carry out the steps when, by way of the input or the input signal, a change of the viewing distance is defined, by way of which the viewing distance exceeds or falls short of a threshold value.

12. The autostereoscopic screen according to claim 10 , characterised in that for at least one integer k≧1 there is such a threshold value L k which is defined as
L k =L n ×K −1 ×(1+ v )/( k+ 1),

wherein L n indicates a nominal viewing distance of the autostereoscopic screen,
K is a factor which is defined in that light departing from two adjacent strips of pixels, at the nominal viewing distance falls laterally offset by K×IPD through a viewing plane orientated parallel to the screen, wherein IPD is defined as the pupil distance of an average eye pair, and v a parameter which has a value of between 0 and 1,
and wherein the control unit is configured, on falling short of this threshold value L k , to increase a number of strips of pixels, from which all or a majority of the bands are formed in each case, from k to k+1, and on exceeding this threshold value L k , to reduce the number of strips of pixels, from which all or a majority of the bands are formed in each case, from k+1 to k.

13. The autostereoscopic screen according to claim 1 , wherein the control unit is configured to fix the number of subsets and accordingly the plurality of the reproduced stereoscopic half-pictures in dependence on a manual input or an input signal.

14. A method for the simultaneous reproduction of more than two different pictures on an autostereoscopic screen, which comprises a pixel matrix with a multitude of pixels and an optical element arranged in front of or behind the pixel matrix, wherein the pixels of the pixel matrix are arranged in a multitude of parallel strips of pixels, the strips being vertical or inclined with respect to the vertical, and wherein the optical element forms an optical grid with a family of strip-like structures which run parallel to the strips and equidistantly next to one another, said grid in each case setting a defined propagation direction for the lig

Assignees

• Fraunhofer-Gesellschaft Zur Foerderung Der Angewandten Forschung E V

Inventors

• De La Barré René
• Jurk Silvio

Classifications

• G02B30/27

  involving lenticular arrays · CPC title

• G02B26/00

  Optical devices or arrangements for the control of light using movable or deformable optical elements (control of light by modification of the optical properties of the media of the elements involved therein G02F1/00) · CPC title

• H04N13/324

  Colour aspects · CPC title

• H04N13/31

  using parallax barriers · CPC title

• H04N13/373

  for tracking forward-backward translational head movements, i.e. longitudinal movements · CPC title