Compact optical system with improved contrast uniformity

• US 10,012,838 B2
• Filed: 12/16/2015
• Issued: 07/03/2018
• Est. Priority Date: 01/21/2014
• Status: Active Grant

• Current Assignee: Mentor Acquisition One, LLC (Magic Leap, Inc.)
• Original Assignee: Osterhout Design Group
• Inventors: Border, John N.
• Primary Examiner(s): Martinez, Joseph P
• Application Number:
  US14/970,635
• Publication Number:
  US 20160216516A1
• Time in Patent Office: 930 Days
• CPC Class Codes: G02B 2027/0112 comprising device for genereting colour display
• CPC Class Codes: G02B 2027/0116 comprising devices for correcting chromatic aberration
• CPC Class Codes: G02B 2027/0118 comprising devices for improving the contrast of the display / brillance control visibility
• CPC Class Codes: G02B 2027/0123 comprising devices increasing the field of view
• CPC Class Codes: G02B 2027/0127 comprising devices increasing the depth of field
• CPC Class Codes: G02B 2027/013 comprising a combiner of particular shape, e.g. curvature
• CPC Class Codes: G02B 2027/0134 of stereoscopic type
• CPC Class Codes: G02B 2027/0138 comprising image capture systems, e.g. camera
• CPC Class Codes: G02B 2027/014 comprising information/image processing systems
• CPC Class Codes: G02B 2027/0141 characterised by the informative content of the display
• CPC Class Codes: G02B 2027/0147 comprising a device modifying the resolution of the displayed image
• CPC Class Codes: G02B 2027/015 involving arrangement aiming to get less bulky devices
• CPC Class Codes: G02B 2027/0159 with mechanical means other than scaning means for positioning the whole image
• CPC Class Codes: G02B 2027/0178 Eyeglass type eyeglass details G02C
• CPC Class Codes: G02B 2027/0181 Adaptation to the pilot/driver
• CPC Class Codes: G02B 2027/0185 Displaying image at variable distance
• CPC Class Codes: G02B 2027/0187 slaved to motion of at least a part of the body of the user, e.g. head, eye
• CPC Class Codes: G02B 27/0018 with means for preventing ghost images anti-reflection coatings G02B1/11
• CPC Class Codes: G02B 27/0075 with means for altering, e.g. increasing, the depth of field or depth of focus
• CPC Class Codes: G02B 27/0093 with means for monitoring data relating to the user, e.g. head-tracking, eye-tracking
• CPC Class Codes: G02B 27/017 : Head mounted
• CPC Class Codes: G02B 27/0172 : characterised by optical features
• CPC Class Codes: G02B 27/0176 : characterised by mechanical features
• CPC Class Codes: G02B 27/0927 : Systems for changing the beam intensity distribution, e.g. Gaussian to top-hat
• CPC Class Codes: G02B 27/283 : used for beam splitting or combining
• CPC Class Codes: G02B 30/34 : Stereoscopes providing a stereoscopic pair of separated images corresponding to parallactically displaced views of the same object, e.g. 3D slide viewers
• CPC Class Codes: G02B 5/28 : Interference filters
• CPC Class Codes: G02B 5/30 : Polarising elements light-modulating devices with active elements G02F1/00
• CPC Class Codes: G02B 5/3025 : Polarisers, i.e. arrangements capable of producing a definite output polarisation state from an unpolarised input state G02B5/3008, G02B5/3016 take precedence
• CPC Class Codes: G02B 5/3083 : Birefringent or phase retarding elements G02B5/3008, G02B5/3016 take precedence; systems for polarisation control G02B27/286; manufacturing phase modulating patterns by lithographic processes G03F7/001
• CPC Class Codes: G06F 3/011 : Arrangements for interaction with the human body, e.g. for user immersion in virtual reality blind teaching G09B21/00
• CPC Class Codes: G06F 3/013 : Eye tracking input arrangements G06F3/015 takes precedence
• CPC Class Codes: G06F 3/017 : Gesture based interaction, e.g. based on a set of recognized hand gestures interaction based on gestures traced on a digitiser G06F3/04883
• CPC Class Codes: G06F 5/10 : having a sequence of storage locations each being individually accessible for both enqueue and dequeue operations, e.g. using random access memory G06F5/065 takes precedence
• CPC Class Codes: G06T 19/006 : Mixed reality object pose determination, tracking or camera calibration for mixed reality G06T7/00
• CPC Class Codes: G09G 2310/0235 : Field-sequential colour display
• CPC Class Codes: G09G 3/3208 : organic, e.g. using organic light-emitting diodes [OLED]
• CPC Class Codes: H05B 45/10 : Controlling the intensity of the light
• CPC Class Codes: H05B 45/12 : using optical feedback
• CPC Class Codes: H05B 45/20 : Controlling the colour of the light

Abstract

An optical system for a head-worn computer may include a light source positioned within the head-worn computer and adapted to project non-polarized illuminating light towards a partially reflective partially transmissive surface such that the illuminating light reflects through a field lens and towards a reflective display and a polarizing film adjacent to a surface of the reflective display that polarizes the illuminating light after it passes through the field lens. The illuminating light reflects off a surface of the reflective display, forming image light which is then analyzed by the polarizing film prior to being transmitted through the field lens and then through the partially reflective partially transmissive surface to a non-polarizing lower display optical system adapted to present the image light to an eye of a user wearing the head-worn computer.

Claims

1. An optical system for a head-worn computer, comprising:

a light source positioned within the head-worn computer and adapted to project non-polarized illuminating light towards a partially reflective partially transmissive surface such that the illuminating light reflects through a field lens and towards a reflective display; and

a polarizing film adjacent to a surface of the reflective display that polarizes the illuminating light after it passes through the field lens,

wherein the illuminating light reflects off a surface of the reflective display, forming image light which is then analyzed by the polarizing film prior to being transmitted through the field lens and then through the partially reflective partially transmissive surface to a non-polarizing lower display optical system adapted to present the image light to an eye of a user wearing the head-worn computer.

2. The optical system of claim 1, wherein the field lens has more than 30 nm of birefringence.

3. The optical system of claim 1, wherein the polarizing film is an absorptive polarizer.

4. The optical system of claim 1, wherein the polarizing film is a circular polarizer.

5. The optical system of claim 4, wherein the quarter wave film of the circular polarizer faces the reflective display.

6. The optical system of claim 1, wherein the non-polarizing lower display system also provides a see-through view of the surrounding environment.

7. The optical system of claim 1, wherein the reflective display is an LCOS or FLCOS.

8. The optical system of claim 1, wherein the reflective display is an interferometric modulator display.

9. The optical system of claim 1, further comprising a light trap positioned adjacent to a wall of a housing opposite the light source to trap stray light that is not reflected by the partially reflective partially transmissive surface.

10. The optical system of claim 9, wherein the light trap includes flat black paint.

11. The optical system of claim 9, wherein the light trap includes a textured structure.

12. The optical system of claim 1, wherein the partially reflective partially transmissive surface is a segmented surface with at least one flat segment.