Patent ID: 11927734
Assignee: LUMUS LTD.
Field: Optics (Instruments)
Classification: CPC G  B | IPC B  G

Claim 14:
15. An apparatus comprising:
(a) a light guiding element having a plurality of faces including first and second parallel faces, said light guiding element being configured for guiding rays of an image by internal reflection at said first and second parallel faces, one of said plurality of faces providing a coupling surface;
(b) a coupling prism having an interface surface for attachment to said coupling surface and an input surface for input of rays of an image into the light guiding element; and
(c) a quantity of transparent adhesive deployed between said coupling surface and said interface surface so as to form an optically transmissive interface, a part of said quantity of adhesive forming a partial filling of an angled recess between said light guiding element and said coupling prism,, wherein an air gap extends along one of said faces of said light guiding element beneath said partial filling, said air gap terminating at an edge within said adhesive so as to define an optical cutoff edge adjacent to said coupling surface of said light guiding element.