Compact microlenslet arrays imager

• US 7,009,773 B2
• Filed: 08/03/2004
• Issued: 03/07/2006
• Est. Priority Date: 05/23/2001
• Status: Expired due to Term

• 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.
• Primary Examiner(s): MAI, HUY KIM
• Application Number:
  US10/910,148
• Publication Number:
  US 20050007673A1
• Time in Patent Office: 581 Days
• Field of Search: 359/619, 359/621, 359/622, 359/626, 359/630, 349/11, 345 7- 9
• US Class Current: 359/622
• 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 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 a microdisplay within the HMPD or the HMD 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 HMPD or said HMD and within the field of view of said miniature projection optics or said eyepiece optics; and

wherein both of said miniature projection optics or said eyepiece optics and said retro-reflective means are located internally of the external housing of said HMPD or HMD assembly, respectively.

2. The assembly of claim 1, wherein a baffle is located between the second array and the image plane.

3. The assembly of claim 1, 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 image plane.

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

5. The assembly of claim 1 wherein the first baffled microlenslet arrays comprises:

multiple arrays.

6. The assembly of claim 1 wherein the second microlenslet array comprises:

multiple arrays.

7. A method of forming a head mounted display (HMD) or head mounted projection display (HMPD) having 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;

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

(d) further magnifying the images with a miniature projection optics in the HMPD or an eyepiece optics in the HMD; and

(e) disposing the magnified images on a retro-reflective screen, wherein said miniature projection optics or eyepiece optics are integrated on an interior of said HMPD or HMD.

8. The method described in claim 7, further comprising the step of:

combining said the baffle with the second microlenslet array.

9. The method described in claim 7, further comprising the step of:

combining said baffles with the first and the second microlenslet array.

10. The method of claim 7, further comprising the step of:

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