Three-dimensional display using variable focusing lens

• US 20050179868A1
• Filed: 02/13/2004
• Published: 08/18/2005
• Est. Priority Date: 02/13/2004
• Status: Active Grant

• Current Assignee: Stereo D Inc., Stereo Display, Inc.
• Original Assignee: Angstrom, Inc., Stereo Display, Inc.
• Inventors: Seo, Cheong Soo, Cho, Gyoung Il, Baek, Sang Hyune, Gim, Dong Woo, Boyd, James Greenup
• Granted Patent: US 7,077,523 B2
• Time in Patent Office: Days
• US Class Current: 353/7
• 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 three-dimensional display device comprising:

a) a two-dimensional display displaying a first image; and

b) a variable focusing lens receiving light from the two-dimensional display and forming a second image;

wherein the first image comprises a predetermined depth number of first depthwise images that are displayed within a unit time, and the second image comprises corresponding second depthwise images, wherein each of the first depthwise images represents the portion of the first image having the same image depth, wherein the two-dimensional display displays one first depthwise image at a time, wherein the focal length of the variable focusing lens changes according to the depth of the first depthwise image being displayed, wherein the focusing speed of the variable focusing lens is at least equal to the product of the afterimage speed of the human eye and the number of depths, and wherein the variable focusing lens reflects light from the two-dimensional display.

2. The three-dimensional display device of claim 1, wherein the variable focusing lens is made of a micromirror array lens.

3. The three-dimensional display device of claim 2, wherein the variable focusing lens is a reflective Fresnel lens.

4. The three-dimensional display device of claim 2, 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.

5. The three-dimensional display device of claim 4, wherein the micromirrors are arranged in a flat plane.

6. The three-dimensional display device of claim 5, wherein the micromirrors are arranged to form one or more concentric circles.

7. The three-dimensional display device of claim 4, wherein the translational motion of each of the micromirrors is controlled.

8. The three-dimensional display device of claim 4, wherein the rotational motion of each of the micromirrors is controlled.

9. The three-dimensional display device of claim 4, wherein the rotational motion and the translational motion of each of the micromirrors are controlled.

10. 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.

11. 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.

12. 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.

13. The three-dimensional display device of claim 12, further comprising a screen for displaying the second image, and wherein the auxiliary lens increases the size of the screen.

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

15. A three-dimensional display device wherein an image of an object is divided into sectional images along the depth of the object, and each sectional image is focused at the depth of the sectional image so that image focused from the sectional images looks three-dimensional to a viewer, the three-dimensional device comprising:

a) a two-dimensional display displaying a predetermined depth number of first images; and

b) a variable focusing lens receiving light from the two-dimensional display and forming a second image;

wherein the focusing speed of the variable focusing lens is at least equal to the product of the afterimage speed of the human eye and the number of depths, and wherein the variable focusing lens reflects light from the two-dimensional display.

16. The three-dimensional display device of claim 15, wherein the variable focusing lens is made of a micromirror array lens, 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.

17. The three-dimensional display device of claim 16, wherein the variable focusing lens is a reflective Fresnel lens.

18. A three-dimensional display method comprising the steps of:

a) displaying a first depthwise image in two-dimension;

b) displaying a second depthwise image by receiving light from the displayed first depthwise image and focusing the light according to the depth of the first depthwise image; and

c) repeating steps a) and b) for a predetermined depth number of the first depthwise images within a unit time;

wherein the predetermined number of the first depthwise images forms a first image, and each of the first depthwise images represents the portion of the first image having the same image depth, wherein the focusing speed in the step of displaying the second depthwise images is at least equal to the product of the afterimage speed of the human eye and the number of depths, and wherein in the step of displaying the second depthwise images, the light received from the displayed first depthwise image is reflected.

19. The three-dimensional display method of claim 18, wherein the step of displaying the second depthwise images is performed with a micromirror array lens.

20. A three-dimensional display device comprising:

a) a two-dimensional display comprising a plurality of pixels; and

b) a plurality of variable focusing lenses, each of the variable focusing lenses corresponds to each of the pixels;

wherein the focusing speed of the variable focusing lens is at least equal to the afterimage speed of the human eye, and each of the variable focusing lenses reflect light from the two-dimensional display, and wherein the focal length of each of the variable focusing lenses changes according to the image depth of an image displayed by each of the pixels.

21. The three-dimensional display device of claim 20, wherein each of the variable focusing lenses is made of a micromirror array lens.