Three-dimensional display using variable focusing lens

• US 7,077,523 B2
• Filed: 02/13/2004
• Issued: 07/18/2006
• Est. Priority Date: 02/13/2004
• Status: Active Grant

• Current Assignee: Stereo D Inc., Stereo Display, Inc.
• Original Assignee: Angstorm Incorporated, Stereo Display, Inc.
• Inventors: Seo, Cheong Soo, Cho, Gyoung Il, Baek, Sang Hyune, Gim, Dong Woo, Boyd, James Greenup
• Primary Examiner(s): KOVAL, MELISSA J
• Application Number:
  US10/778,281
• Publication Number:
  US 20050179868A1
• Time in Patent Office: 886 Days
• Field of Search: 353/10, 353/122, 353/102, 359290-292, 359/15, 359/619, 359625-627, 359/630, 359/631, 359/633, 359/666, 359/851, 349/95, 396/18
• US Class Current: 353/10
• 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: G03B 21/008 using micromirror devices
• CPC Class Codes: G03B 35/00 Stereoscopic photography
• CPC Class Codes: H04N 13/322 using varifocal lenses or mirrors
• 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 three-dimensional display device includes a two-dimensional display displaying a first image, and a variable focusing lens receiving light from the two-dimensional display and forming a second image. The variable focusing lens reflects light from the two-dimensional display. The first image includes a predetermined number of first depthwise images that are displayed within a unit time, and the second image includes corresponding second depthwise images. Each depthwise image represents the portion of the first image having the same image depth, and the two-dimensional display displays one depthwise image at a time. The focal length of the variable focusing lens changes according to the depth of the depthwise image being displayed. A micromirror array lens is used as the variable focusing lens. The micromirror array lens has enough speed and focusing depth range for realistic three-dimensional display.

Claims

1. A volumetric three-dimensional display device for displaying an object comprising:

a) a display means for presenting two-dimensional images (first images), wherein the two-dimensional images are the image representatives of the cross section of the object at different positions along the third dimension,; and

b) a Micromirror Array Lens receiving light from the display means and forming a three-dimensional image by imaging two-dimensional images (second images);

wherein the Micromirror Array Lens is a Diffractive-Reflective Hybrid Fresnel Variable Focusing Lens, wherein the changing rate of the focal length is at least equal to the product of a number of cross-sectional images times persistence rate (afterimage speed) of average human eye so that the two-dimensional images with different imaging planes appear to fuse into a three-dimensional image of an object to a viewer, wherein the focal length of the Micromirror Array Lens is controlled to change imaging planes of the two-dimensional images along the third dimension.

2. The three-dimensional display device of claim 1, wherein the micromirror array lens comprises a plurality of micromirrors, and wherein each micromirror is controlled to change the focal length of the variable focusing lens.

3. The three-dimensional display device of claim 1, further comprising a beam splitter positioned in the path of light between the two-dimensional display and the variable focusing lens.

4. The three-dimensional display device of claim 1, wherein the variable focusing lens is positioned so that the path of the light reflected by the variable focusing lens is not blocked by the two-dimensional display.

5. The three-dimensional display device of claim 1, further comprising an auxiliary lens having a predetermined focal length, and wherein the second image is formed by the variable focusing lens and the auxiliary lens together.

6. The three-dimensional display device of claim 1, wherein the focal length of the variable focusing lens is controlled to be fixed.

7. The three-dimensional display device of claim 2, wherein the micromirrors are arranged in a flat plane, wherein the micromirrors are arranged to form one or more concentric circles.

8. The three-dimensional display device of claim 2, wherein the translational motion of each of the micromirrors is controlled.

9. The three-dimensional display device of claim 2, wherein the rotational motion of each of the micromirrors is controlled.

10. The three-dimensional display device of claim 2, wherein the rotational motion and the translational motion of each of the micromirrors are controlled.

11. The three-dimensional display device of claim 5, further comprising a screen for displaying the second image, and wherein the auxiliary lens increases the size of the screen.

12. The three-dimensional display device of claim 1, the micromirror array lens is synchronized with the two-dimensional display to display the two-dimensional first images according to its depths.