Method and system using refractive beam mapper having square element profiles to reduce moire interference in a display system including multiple displays

• US 10,684,491 B2
• Filed: 01/19/2017
• Issued: 06/16/2020
• Est. Priority Date: 10/02/2015
• Status: Active Grant

• Current Assignee: Aptiv Technologies AG
• Original Assignee: Pure Depth Limited
• Inventors: Bell, Gareth P., Singh, Darryl
• Primary Examiner(s): Parikh, Dakshesh D
• Application Number:
  US15/409,711
• Publication Number:
  US 20170131558A1
• Time in Patent Office: 1,244 Days
• Field of Search: None
• CPC Class Codes: G02B 27/0927 Systems for changing the beam intensity distribution, e.g. Gaussian to top-hat
• CPC Class Codes: G02B 27/0961 Lens arrays lens arrays per se G02B3/0006
• CPC Class Codes: G02B 30/27 involving lenticular arrays
• 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: H04N 13/305 using lenticular lenses, e.g. arrangements of cylindrical lenses
• 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 2213/001 Constructional or mechanical details

Abstract

A multi-display system (e.g., a display including multiple display panels) includes at least first and second displays (e.g., display panels or display layers) arranged substantially parallel to each other in order to display three-dimensional (3D) features to a viewer(s). An optical element(s) such as at least a refractive beam mapper (RBM) is utilized in order to reduce moiré interference.

Claims

1. A display device comprising:

a first display in a first plane for displaying a first image;

a second display in a second plane for displaying a second image, wherein said first and second planes are approximately parallel to each other;

a beam mapping element located between the first and second displays and comprising a microlens array including a plurality of microlenses configured to direct rays output from the second display through sub-pixels of the first display and toward a viewer, wherein each of the microlenses in the array has a substantially square profile as viewed from above, from a point of view of a viewer normal to the display device, in order to improve image quality, and

wherein each of the microlenses has a phase number M of at least 8 and a width substantially the same as a width of a corresponding pixel in at least one of the displays, and covers the pixel.

2. The display device of claim 1, wherein the beam mapping element comprises a refractive beam mapper.

3. The display device of claim 1, wherein the beam mapping element is configured to direct rays output from the second display in a pseudo random manner through sub-pixels of the first display and toward a viewer.

4. The display device of claim 1, wherein the beam mapping element has asymmetric scattering angles.

5. The display device of claim 1, wherein the beam mapping element substantially preserves polarization.

6. The display device of claim 1, wherein the beam mapping element has refractive optics for realizing substantially a flat top profile, such that a far field pattern of output is close to a flat top profile.

7. The display device of claim 1, wherein the beam mapping element limits divergence from any point on the second display to less than a distance of one pixel offset when the rays proceed through the first display.

8. The display device of claim 1, wherein each of the microlenses has a diameter no greater than a length and/or a width of a subpixel in the second display.

9. The display device of claim 1, wherein the microlenses have a distribution of surface normals between 0 and approximately 20 degrees.

10. The display device of claim 1, wherein the beam mapping element is laminated to the second display.

11. The display device of claim 1, wherein curved surfaces of the microlenses contact a refractive index material having a refractive index of at least 1.4.

12. The display device of claim 1, wherein the second display is a rear display, and the first display is a front display, of the display device.

13. The display device of claim 1, wherein rays from a given subpixel in the second display are directed toward multiple different subpixels of the first display, and wherein rays from a plurality of different subpixels of the second display proceed through a given subpixel of the first display.

14. A method of displaying an image via a display device including a first display in a first plane for displaying a first image, and a second display in a second plane for displaying a second image, wherein said first and second planes are approximately parallel to each other, the method comprising;

directing light rays output from the second display through sub-pixels of the first display and toward a viewer, via a plurality of microlenses each having a substantially square profile as viewed from the point of view of a viewer, the microlenses being located between the first and second displays, and

wherein each of the microlenses has a phase number M of at least 8 and a width substantially the same as a width of a corresponding pixel in at least one of the displays, and covers the pixel.

15. The method of claim 14, wherein the microlenses are laminated to the second display.

16. The method of claim 14, wherein the second display is a rear display, and the first display is a front display, of the display device.

17. The method of claim 14, wherein rays from a given subpixel in the second display are directed toward multiple different subpixels of the first display, and wherein rays from a plurality of different subpixels of the second display proceed through a given subpixel of the first display.