MULTI-PLANAR VOLUMETRIC DISPLAY SYSTEM AND METHOD OF OPERATION

• US 20020130820A1
• Filed: 03/20/2002
• Published: 09/19/2002
• Est. Priority Date: 04/20/1998
• Status: Active Grant

• Current Assignee: Lightspace Technologies, Inc. (LC-Tec Holding AB)
• Original Assignee: LightSpace Technologies AB (LC-Tec Holding AB)
• Inventors: Sullivan, Alan
• Granted Patent: US 6,806,849 B2
• Time in Patent Office: Days
• US Class Current: 345/6
• CPC Class Codes: G02B 30/52 the 3D volume being constructed from a stack or sequence of 2D planes, e.g. depth sampling systems
• CPC Class Codes: G06T 15/00 3D [Three Dimensional] image rendering
• CPC Class Codes: G09G 3/003 to produce spatial visual effects
• CPC Class Codes: H04N 13/363 using image projection screens volumetric display H04N13/388
• CPC Class Codes: H04N 13/388 Volumetric displays, i.e. systems where the image is built up from picture elements distributed through a volume
• CPC Class Codes: H04N 13/395 with depth sampling, i.e. the volume being constructed from a stack or sequence of 2D image planes
• CPC Class Codes: H04N 13/398 Synchronisation thereof; Control thereof

Abstract

A multi-planar volumetric display system and method of operation generate volumetric three-dimensional images using a multi-surface optical device including a plurality of individual optical elements arranged in an array; and an image projector for selectively projecting images on respective optical elements to generate a first volumetric three-dimensional image viewable in the multi-surface optical device. A floating-image generator may also be included for projecting the first volumetric three-dimensional image to generate a second volumetric three-dimensional image viewable as floating in space at a location separate from the multi-surface optical device.

Claims

1. A method for performing anti-aliasing of a first voxel of a three-dimensional image displayed on a plurality of optical elements, wherein a first voxel depth value of the first voxel is between a pair of optical element depth values corresponding to a pair of optical elements bounding the first voxel, the method comprising the steps of:

generating a depth adjustment value from the first voxel depth value;

adjusting a first color value associated with the first voxel using the depth adjustment value; and

displaying a second voxel on at least one of the pair of optical elements using the adjusted color value.

2. The method of claim 1, further comprising the step of:

scaling the first voxel depth value to be within a predetermined range of indices associated with the plurality of optical elements; and

wherein the step of generating the depth adjustment value includes the step of generating the depth adjustment value from the scaled voxel depth value.

3. The method of claim 2, wherein the step of generating the depth adjustment value includes the step of:

determining a fractional portion of the scaled voxel depth value to be the depth adjustment value.

4. The method of claim 3, wherein the step of adjusting the first color value includes the step of:

multiplying the first color value by a function of the fractional portion to generate a second color value as the adjusted color value, with the second color value being associated with the second voxel.

5. The method of claim 1, wherein the step of generating the depth adjustment value includes the step of:

modifying the depth adjustment value with an anti-aliasing parameter to control the degree of anti-aliasing of the display of the first voxel in the three-dimensional image.

6. The method of claim 1, wherein the step of adjusting the first color value includes the step of generating second and third color values from the first color value adjusted using the depth adjustment value;

and

wherein the step of displaying the second voxel includes the step of;

displaying the second voxel and a third voxel on a respective one of the pair of optical elements using the second and third color values, respectively.

7. The method of claim 6, wherein the plurality of optical elements are uniformly spaced.

8. The method of claim 6, wherein the plurality of optical elements are not uniformly spaced.

9. The method of claim 6, wherein the plurality of optical elements have variable spacings therebetween.

10. The method of claim 6, wherein the step of determining the pair of optical elements includes the steps of:

searching through a plurality of depth values associated with the plurality of optical elements to determine the pair of optical elements wherein the first voxel depth value of the first voxel is between the pair of optical element depth values associated with the pair of optical elements.

11. The method of claim 6, wherein the step of generating the depth adjustment value includes the step of:

generating the depth adjustment value from the first voxel depth value and the optical element depth values associated with the voxel and the pair of optical elements, respectively.

12. The method of claim 1, wherein the step of generating a depth adjustment value includes the step of:

interpolating the first voxel depth value D_V with the pair of optical element depth values D_NEAR1 and D_NEAR2 according to;

$\mathrm{\lambda <br><br>}=<br><br>\frac{D_V-D_{\mathrm{NEAR1}}}{D_{\mathrm{NEAR1}}-D_{\mathrm{NEAR2}}}<br><br>$

in which |X| is the absolute value or magnitude function of a value or variable X.

14. The method of claim 13, further comprising the step of:

projecting the first volumetric three-dimensional image from the multi-surface optical device using a floating-image generator, to generate a second volumetric three-dimensional image viewable as floating in space at a location separate from the multi-surface optical device.

15. The method of claim 14 further comprising the step of:

controlling the translucency of each of the plurality of individual optical elements of the multi-surface optical device using an optical element controller to respectively receive and display the anti-aliased slices.

16. The method of claim 15, wherein the step of controlling includes the steps of:

causing a single liquid crystal element to have an opaque light-scattering state to receive and display the anti-aliased slices; and

causing the remaining liquid crystal elements to have a translucency to allow the set of images to be respectively projected thereon.

18. The system of claim 17, further comprising:

a floating-image generator for projecting the first volumetric three-dimensional image from the multi-surface optical device to generate a second volumetric three-dimensional image viewable as floating in space at a location separate from the multi-surface optical device.

19. The system of claim 17, wherein each of the plurality of individual optical elements of the multi-surface optical device includes a liquid crystal element having a controllable variable translucency to receive the anti-aliased images.

20. The system of claim 19, further comprising:

an optical element controller for controlling the translucency of the liquid crystal elements wherein;

a single liquid crystal element is controlled to have an opaque light-scattering state to receive and display the respective one of the set of anti-aliased images from the image projector; and

the remaining liquid crystal elements are controlled to be substantially transparent to allow the viewing of the displayed image on the opaque liquid crystal element.

13. A method for generating volumetric three-dimensional images, the method comprising the steps of:

providing image data corresponding to a set of two-dimensional slices of a three-dimensional image to an image projector; and

selectively projecting each of the two-dimensional slices from the image projector onto a respective optical element selected from a plurality of optical elements forming a multi-surface optical device, including the steps of;

performing anti-aliasing of voxels at transitions between at least one pair of the optical elements to generate the slices with adjusted color values derived from the anti-aliased voxels; and

generating a first volumetric three-dimensional image viewable in the multi-surface optical device from the anti-aliased slices selectively projected on the plurality of liquid crystal elements.

17. A system for generating volumetric three-dimensional images, the system comprising:

a multi-surface optical device including a plurality of individual optical elements arranged in an array; and

an image projector for performing anti-aliasing of voxels at transitions between pairs of the optical elements to generate the slices with adjusted color values derived from the anti-aliased voxels, and for selectively projecting a set of images including the anti-aliased voxels on respective optical elements of the multi-surface optical device to generate a first volumetric three-dimensional image viewable in the multi-surface optical device.