Optical see-through free-form head-mounted display

Patent metadata

Field	Value
Publication number	US-9239453-B2
Application number	US-201314010956-A
Country	US
Kind code	B2
Filing date	Aug 27, 2013
Priority date	Apr 20, 2009
Publication date	Jan 19, 2016
Grant date	Jan 19, 2016

Abstract

A see-through free-form head-mounted display including a wedge-shaped prism-lens having free-form surfaces and low F-number is provided.

First claim

What is claimed is:

1. A free-form prism-lens for use in an optical see-through head-mounted display, comprising:
a first free-form surface configured to receive light from a micro-display and configured to transmit the received light into the body of the prism-lens;
a second free-form surface configured to receive the light transmitted into the body of the prism-lens from the first free-form surface and configured to totally internally reflect the received light at the second surface; and
a third free-form surface configured to receive the light reflected by the second free-form surface and configured to reflect the light out of the prism-lens,
wherein the prism-lens has an f-number less than 3.5 and an effective focal length of 21 mm or less, wherein the exit pupil diameter is at least 6 mm.

2. The free-form prism-lens according to claim 1 , wherein the first free-form surface is described by

z
=

c
⁡

(

x
2

+

y
2

)

1
+

sqrt
⁡

(

1
-

(

1
+
k

)

⁢

c
2

⁡

(

x
2

+

y
2

)

)

+

∑

j
=
2

66

⁢

⁢

C
j

⁢

x
m

⁢

y
n

,

⁢

j
=

[

(

m
+
n

)

2

+
m
+

3
⁢
n

]

/
2

+
1

,

where the z is the sag of the first free-form surface measured along the z-axis of a local x, y, z coordinate system, c is the vertex curvature (CUY), k is the conic constant, and C j is the coefficient for x m y n .

3. The free-form prism-lens according to claim 2 , wherein the second free-form surface is described by

z
=

c
⁡

(

x
2

+

y
2

)

1
+

sqrt
⁡

(

1
-

(

1
+
k

)

⁢

c
2

⁡

(

x
2

+

y
2

)

)

+

Assignees

• Cheng Dewen
• Hua Hong
• Wang Yongtian
• Beijing Inst Technology
• Univ Arizona State

Inventors

• Cheng Dewen
• Hua Hong
• Wang Yongtian

Classifications

• G02B13/10

  involving prisms (G02B13/12 takes precedence) · CPC title

• G02B2027/013

  comprising a combiner of particular shape, e.g. curvature · CPC title

• G02B17/086

  wherein the system is made of a single block of optical material, e.g. solid catadioptric systems · CPC title

• G02B2027/0118

  comprising devices for improving the contrast of the display / brillance control visibility · CPC title

• G02B27/017

  Head mounted · CPC title