Autostereoscopic screen and method for reproducing a 3D image

• US 9,398,291 B2
• Filed: 04/30/2012
• Issued: 07/19/2016
• Est. Priority Date: 04/03/2012
• Status: Active Grant

• Current Assignee: Fraunhofer Gesellschaft Zur Foerderung Der Angewandten Forsching E.V.
• Original Assignee: Fraunhofer Gesellschaft Zur Foerderung Der Angewandten Forsching E.V.
• Inventors: de la Barr, Ren, Jurk, Silvio
• Primary Examiner(s): MARINELLI, PATRICK
• Application Number:
  US14/390,759
• Publication Number:
  US 20150163481A1
• Time in Patent Office: 1,541 Days
• US Class Current: 1/1
• CPC Class Codes: H04N 13/302 for viewing without the aid of special glasses, i.e. using autostereoscopic displays
• CPC Class Codes: H04N 13/351 for displaying simultaneously
• CPC Class Codes: H04N 13/373 for tracking forward-backward translational head movements, i.e. longitudinal movements
• CPC Class Codes: H04N 2213/001 Constructional or mechanical details

Abstract

An autostereoscopic screen including a pixel matrix, an optical element, and a control unit. The pixel matrix having a multitude of disjoint subsets of pixels, with each of the subsets forming a family of parallel strips of pixels having a vertical or inclined to vertical course, wherein the subsets cyclically alternate in the horizontal direction. The optical element having a grating-like structure parallel to the strips, which sets a propagation direction of light emitted from the pixels, so that at a nominal distance from the screen, a number corresponding to the multitude, of viewing zones laterally offset relative to one another, are defined with each of the viewing zones assigned to one of the subsets and the light emitted from each of the subsets deflected into the viewing zone of the subset, the control unit for activating the pixel matrix in dependence on image data which defines a 3D-image.

Claims

1. An autostereoscopic screen for the simultaneous reproduction of several different images, comprising:

a pixel matrix, on which a multitude of at least six or at least eight disjoint subsets of pixels are defined such that each of the subsets forms a family of parallel strips of pixels with a vertical course or one which is inclined to a vertical, wherein the strips of the different subsets cyclically alternate in the horizontal direction,

an optical element which is arranged in front of or behind the pixel matrix and which has a grating-like structure orientated parallel to the strips and in each case sets a defined propagation direction of the light emitted or transmitted from the pixels, so that at a nominal distance (D_n) in front of the screen and which is set by a geometry of the screen, a number corresponding to the multitude, of viewing zones laterally offset relative to one another, are defined such that each of the viewing zones is assigned to exactly one of the subsets and that the light departing or transmitted from each of the subsets of pixels is deflected into the viewing zone assigned to this subset, and

a control unit for activating the pixel matrix in dependence on image data which define a 3D-image,

wherein a lateral offset (b) between the directly adjacent strips in each case is so small that the mentioned viewing zones at the nominal distance (D_n) in front of the screen are laterally offset with respect to the directly adjacent viewing zones in each case by less than an average eye distance,

wherein the control unit, for activating the pixel matrix for an autostereoscopic viewing of the 3D-image from a viewing distance (D) in front of the screen, said distance being different to the nominal distance (D_n), is configured to carry out the following steps;

defining a plurality smaller compared to the mentioned multitude, of at least three or at least four disjoint part-sets of the pixels of the pixel matrix which are different to the subsets, in a manner such that each of the part-sets forms a family of parallel bands, wherein each of these bands or each of the majority of the bands or each of at least some of the bands is formed by way of grouping together at least two of the strips of pixels which lie directly next to one another, and wherein the bands of the different part-sets cyclically alternate in the horizontal direction, and

reproducing a number corresponding to the plurality, of stereoscopic half-images which are defined by the image data and complement one another in pairs into a stereo-image perceivable as a 3D-image, by way of the pixels of the pixel matrix, in a manner such that in each case one of the stereoscopic half-images is reproduced on each of the thus defined part-sets,

wherein the part-sets and bands are defined such that at the viewing distance (D) in front of the screen, a number corresponding to the plurality, of regions which are laterally offset to one another, is defined such that each of these regions is assigned to exactly one of the part-sets and that the light departing or transmitted from each of the part-sets of pixels is deflected by the optical element into the region assigned to this part-set, wherein a line which runs through the respective band in the longitudinal direction and which is defined in that the light departing from this line falls exactly centrally into one of the regions, lies in each of the bands next to the middle of this band by no more than half the lateral offset (b).

2. The screen of claim 1, wherein the viewing zones at the nominal distance (D_n) in front of the screen are laterally offset with respect to the directly adjacent viewing zones in each case at the most by half an average eye distance.

3. The screen of claim 1, wherein the regions at the viewing distance (D) in front of the screen, are laterally offset with respect to the directly adjacent regions in each case by more than half the average eye distance.

4. The screen of claim 1, wherein the viewing distance (D) differing from the nominal distance (D_n) is smaller than the nominal viewing distance (D_n).

5. The screen of claim 1, wherein the control unit is configured for the manual input or for the entry of a parameter which defines a distance value, wherein the control unit is configured to activate the pixel matrix such that the viewing distance (D) corresponds to this distance value.

6. The screen of claim 1, comprising a tracking device for determining a distance between an eye pair of at least one viewer and the screen, wherein the control unit is configured to activate the pixel matrix such that the viewing distance (D) corresponds to the distance determined by the tracking device.

7. The screen of claim 6, wherein the tracking device is configured to determine a lateral position of the at least one eye pair, wherein the control unit is configured to activate the pixel matrix in dependence on the lateral position determined by the tracking device, so that the at least one eye pair is located in a field which is spanned by the regions and from which the stereo-image is autostereoscopically visible.

8. The screen of claim 1, wherein the optical element is controllable and forms lens elements with refraction characteristics which can be changed depending on an activation of the optical element, wherein the control unit is configured to activate the optical element depending on the viewing distance (D), in order to adapt refraction characteristics of the lens elements to this viewing distance (D).

9. A method for reproducing a 3D-image on an autostereoscopic screen with a pixel matrix and with an optical element arranged in front of or behind the pixel matrix,

wherein a multitude of at least six or at least eight disjoint subsets of pixels are defined on the pixel matrix such that each of the subsets forms a family of parallel strips of pixels with a course which is vertical or inclined with respect to the vertical, wherein the strips of the different subsets cyclically alternate in the horizontal direction,

and wherein the optical element has a grating-like structure orientated parallel to the strips and in each case sets a defined propagation direction for light departing or transmitted from the pixels, so that at a nominal distance (D_n) in front of the screen and set by a geometry of the screen, a number corresponding to the multitude, of viewing zones laterally offset to one another are defined such that each of the viewing zones is assigned to exactly one of the subsets and that the light departing or transmitted from each of the subsets of pixels is deflected into the viewing zone assigned to this subset,

wherein the pixel matrix is activated in dependence on image data which define a 3D-image,

wherein

a lateral offset (b) between the directly adjacent strips in each case is so small, that the mentioned viewing zones at the nominal distance (D_n) in front of the screen are laterally offset with respect to the directly adjacent viewing zones, in each case by less than an average eye distance,

and the pixel matrix is activated for an autostereoscopic viewing of the 3D-image from a viewing distance (D) in front of the screen, said distance being different to the nominal distance (D_n), wherein the method comprises the following steps:

defining a plurality smaller compared to the multitude, of at least three or at least four disjoint part-sets of the pixels of the pixel matrix, which are different to the subsets, in a manner such that each of the part-sets forms a family of parallel bands, wherein each of these bands or each of the majority of the bands or each of at least some of the bands is formed by way of grouping together at least two of the mentioned strips of pixels which lie directly next to one another, and wherein the bands of the different part-sets cyclically alternate in the horizontal direction, and

reproducing a number corresponding to the mentioned plurality, of stereoscopic half-images which are defined by the image data and complement one another in pairs into a stereo-image perceivable as a 3D image, by way of the pixels of the pixel matrix, in a manner such that in each case one of the stereoscopic half-images is reproduced on each of the thus defined part-sets,

wherein the part-sets and bands are defined such that at the mentioned viewing distance (D) in front of the screen, a number corresponding to the plurality, of regions laterally offset to one another are defined such that each of these regions is assigned to exactly one of the part-sets and that the light departing or transmitted from each of the part-sets of pixels is deflected by the optical element into the region assigned to this part-set, wherein a line which runs in the longitudinal direction through the respective band and which is defined in that the light departing from this line falls exactly centrally into one of the regions, lies in each of the bands next to the middle of this band by not more than half the lateral offset (b).

10. The method of claim 9, comprising a parameter which defines a distance value is inputted into a control unit of the screen or transferred to the control unit, wherein the pixel matrix is activated by the control unit such that the viewing distance (D) corresponds to this distance value.

11. The method of claim 9, comprising a distance between an eye pair of at least one viewer and the screen is detected, wherein the pixel matrix is activated such that the viewing distance (D) corresponds to the thus detected distance.

12. The method of claim 11, comprising a lateral position of the at least one eye pair is to be detected, wherein the pixel matrix is then activated in dependence on the detected lateral position such that the at least one eye pair is located in a field which is spanned by the regions and from which the stereo-image is autostereoscopically viewable.