Compact microlenslet arrays imager

• US 20050007673A1
• Filed: 08/03/2004
• Published: 01/13/2005
• Est. Priority Date: 05/23/2001
• Status: Active Grant

• Current Assignee: University of Central Florida (State University System of Florida)
• Original Assignee: University of Central Florida (State University System of Florida)
• Inventors: Rolland, Jannick P., Martins, Ricardo F., Chaoulov, Vesselin I.
• Granted Patent: US 7,009,773 B2
• Time in Patent Office: Days
• US Class Current: 359/630
• CPC Class Codes: G02B 2027/011 comprising device for correcting geometrical aberrations, distortion
• CPC Class Codes: G02B 2027/0116 comprising devices for correcting chromatic aberration
• CPC Class Codes: G02B 2027/0134 of stereoscopic type
• CPC Class Codes: G02B 27/0172 characterised by optical features
• CPC Class Codes: G02B 3/0062 Stacked lens arrays, i.e. refractive surfaces arranged in at least two planes, without structurally separate optical elements in-between
• CPC Class Codes: G02B 3/04 with continuous faces that are rotationally symmetrical but deviate from a true sphere , e.g. so called "aspheric" lenses

Abstract

Extremely compact and light-weight optical systems, apparatus, devices and methods to image miniature displays. Such systems include, for example, head-mounted projection displays (HMPD), head-mounted displays (HMDs), and cameras for special effects, compact microscopes and telescopes as well as applications in which magnification and compactness are design criteria. The invention includes an ultra-compact imaging system based on microlenslet arrays and demonstrates that such a system can achieve an object-to-image distance as low as approximately 1.7 mm. with the usage of commercially available microlenslet arrays. The replacement of bulk macro-optical system by multi-aperture micro-optics is achieved.

Claims

1. A compact optical assembly comprising:

(a) a first set of baffles;

(b) a first microlenslet array adjacent to said baffles; and

(c) a second microlenslet array adjacent to said first microlenslet array;

whereby the combination of the baffles, the first microlenslet array, and the second microlenslet array allows for magnified images with an assembly of reduced weight and reduced overall object to image length.

2. The assembly of claim 1, wherein at least one of the baffles is located between the second array and the images.

3. The assembly of claim 1, wherein the baffles are located between the object and the first microlens array and between the second microlens array and the images.

4. The assembly of claim 1, where the microlenslet arrays are aspherical shaped.

5. A compact optical assembly useful for head mounted projection display (HMPD) or head-mounted displays (HMDs) comprising:

(a) a first baffled microlenslet array and a second cooperating microlenslet array which provide an optical means for magnifying images written on the microdisplay within the HMPD before imaging to the users'"'"' eye

(b) miniature projection optics for further magnifying the images in HMPD or an eyepiece optics for further magnifying the images in HMD; and

(c) retro-reflective means for receiving said magnified images by disposing them on a micro-structures retro-reflective screen integrated on the interior surface of said head mounted projection display and within the field of view of said optical magnifying means; and

wherein both of said optical means and said retro-reflective means are located internally of the external housing of said HMPD assembly.

6. The assembly of claim 5, wherein a baffle is located between the second array and the images.

7. The assembly of claim 5, wherein a baffle is located between an object and the first microlens array and wherein another baffle is located between the second microlens array and the images.

8. The assembly of claim 5, where the microlenslet arrays are aspherical shaped.

9. The assembly of claim 5 wherein the first baffled microlenslet arrays comprises:

multiple arrays.

10. The assembly of claim 5 wherein the second microlenslet array comprises:

multiple arrays.

11. An optical lens assembly comprising in combination:

(a) a baffled first microlenslet array; and

,

(b) a common axially disposed second microlenslet array, whereby a viewed object is seen as an image of increased size to a user of the optical lens assembly.

12. The assembly of claim 11, wherein a baffle is located between the second array and the image.

13. The assembly of claim 11, wherein a baffle is located between the object and the first microlenslet array and another baffle is located between the second microlenslet array and the image.

14. The assembly of claim 11, where the microlenslet arrays are aspherical shaped.

15. An optical lens assembly comprising in combination:

(a) a baffled first microlenslet array; and

,

(b) a common axially disposed second microlenslet array, whereby a viewed object is seen as an image of decreased size to a user of the optical lens assembly.

16. The assembly of claim 15, wherein a baffle is located between the second array and the image.

17. The assembly of claim 15, wherein a baffle is located between the object and the first microlenslet array and another baffle is located between the second microlenslet array and the image.

18. The assembly of claim 15, where the microlenslet arrays are aspherical shaped.

19. An optical lens assembly comprising in combination:

(a) a baffled first microlenslet array; and

,

(b) a common axially disposed second microlenslet array, whereby a viewed object is seen as an image of same size to a user of the optical lens assembly.

20. The assembly of claim 19, wherein a baffle is located between the second array and the image.

21. The assembly of claim 19, wherein a baffle is located between the object and the first microlenslet array and another baffle is located between the second microlenslet array and the image.

22. The assembly of claim 19, where the microlenslet arrays are aspherical shaped.

23. A method of forming a compact lens display assembly comprising the steps of:

(a) combining a baffle with a first microlenslet array; and

(b) combining said combined baffle and first microlenslet array with a second microlenslet array; and

(c) providing images of an object to be viewed by a user of the compact lens display assembly with said combined baffle and said first microlenslet array and said second microlenslet array.

24. The method described in claim 23, wherein the baffle is combined with the second microlenslet array.

25. The method described in claim 23, wherein baffles are combined both with the first and the second microlenslet array.

26. The method of claim 23, further comprising:

providing a distance between the object and the image as low as approximately 1.7 mm.