US 12,111,471 B2
Free-form prism-lens group and near-eye display apparatus
Dewen Cheng, Beijing (CN); and Qiwei Wang, Beijing (CN)
Assigned to Beijing NED+AR Display Technology Co., Ltd., Beijing (CN)
Filed by Beijing NED+AR Display Technology Co., Ltd., Beijing (CN)
Filed on Apr. 10, 2022, as Appl. No. 17/658,651.
Application 17/658,651 is a continuation of application No. 16/423,005, filed on May 25, 2019, granted, now 11,327,308.
Application 16/423,005 is a continuation of application No. PCT/CN2017/113080, filed on Nov. 27, 2017.
Claims priority of application No. 201611123106.6 (CN), filed on Dec. 8, 2016.
Prior Publication US 2022/0236572 A1, Jul. 28, 2022
Int. Cl. G02B 27/01 (2006.01); G02B 5/04 (2006.01); G02B 27/09 (2006.01); G02B 27/12 (2006.01); G06F 3/01 (2006.01)
CPC G02B 27/0172 (2013.01) [G02B 5/04 (2013.01); G02B 27/01 (2013.01); G02B 27/0955 (2013.01); G02B 27/0972 (2013.01); G02B 27/12 (2013.01); G06F 3/011 (2013.01); G02B 2027/011 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A free-form prism-lens group, comprising: a primary prism, a first auxiliary lens, and a second auxiliary lens; wherein:
the primary prism has a plurality of surfaces including only three optical surfaces;
a first optical surface is configured as an incident surface facing a micro-display device for receiving an image light from the micro-display device, and transmitting the image light into the primary prism;
a second optical surface is configured as an exit surface;
a third optical surface is configured to reflect the image light back into the primary prism once during a process of the image light propagated from the first optical surface to the second optical surface and exiting from the primary prism;
the first optical surface, the second optical surface, and the third optical surface are free-form surfaces;
the first auxiliary lens is arranged adjacent to the primary prism and is not configured for imaging of the image light;
the second auxiliary lens is arranged adjacent to the primary prism and a gap with a predetermined thickness is arranged between the second auxiliary lens and the primary prism, and the adjacent surfaces of the primary prism and the second auxiliary lens have consistent free-form surfaces to satisfy the condition of total internal reflection of the image light when the image light reaches the second optical surface for a first time;
the second auxiliary lens extends in a direction perpendicular to an optical axis to cover an effective aperture of the image light entering the second auxiliary lens from the primary prism; and
the primary prism has extended edge portions disposed symmetrically about a vertical plane passing through the optical axis and extending from the first optical surface and the third optical surface, respectively, such that the freeform prism-lens group has a size not limited by the micro-display device, the extended edge portions have non-free-form surfaces and are not configured as optical surfaces for imaging of the image light while having smooth transitions with the first optical surface and the third optical surface, respectively.