Wearable virtual reality and augmented reality display apparatus

A method of displaying augmented reality (AR) or virtual reality (VR) images with a wearable display apparatus, the method comprising:

• generating images with a microdisplay;
• projecting the generated images with a projection optical system including an optical free-form surface;
• and
• coupling the projected images to an optical waveguide through an inclined optical path;
• wherein the optical waveguide comprises a planar waveguide optical element comprising:
• a rectangular prism input coupling end;
• a dichroic mirror array output coupling end;
• wherein parameters of the waveguide include:
• a plate thickness d;
• an angle θ between the dichroic mirror and a plane;
• a distance h1 between the input coupling end and the output coupling end;
• a distance h2 between dichroic mirrors of the array;
• a glass refractive index n;
• wherein of the waveguide device:
• the dichroic mirror array has mirrors parallel to each other;
• the angle θ satisfies 20°≦θ≦40°;
• the distance h2 between dichroic mirrors satisfies h2=d/tan (θ);
• the refractive index n satisfies 1.4≦n≦1.8;
• the thickness d satisfies 1.4≦d≦3.6 mm.

A method of displaying augmented reality (AR) or virtual reality (VR) images with a wearable display apparatus, the method comprising:

• generating images with a microdisplay;
• projecting the generated images with a projection optical system including an optical free-form surface;
• and
• coupling the projected images to an optical waveguide through an inclined optical path;
• wherein the microdisplay device comprises:
• a first and a second microdisplays, configured to display respectively a near and a far observation images relative to a user eye, or display respectively a far and a near observation images relative to the eye, wherein the first and second observation images being displayed have different distances to the user eye, but with substantially fields of view areas being covered, the first image weighted toward describing in a three-dimensional rendering of a scene an object having a nearer depth, the second imaged weighted toward describing in the three-dimensional rendering of the scene an object having a farther depth;
• wherein the projection optical system comprises:
• a first curved optical surface prism configured to magnify and place an image displayed by the first microdisplay at a distance relatively close to the user eye;
• a second curved optical surface prism configured to magnify and place an image displayed by the first microdisplay at a distance relatively far from the user eye;
• the first prism and the second prism surface include a pair of optical surfaces having same shape parameters but opposite signs, i.e., a second optical surface of the first prism and a first optical surface of the second prism, through the two surfaces glued together a seamless connection between the two prisms is achieved, wherein the connection is coated with a half-permeable membrane to achieve an integration of two focal plane images;
• wherein the first prism comprises three optical free-form surfaces, wherein:
• at least one light reflection occurs at one of the optical free-form surfaces, the second optical surface is a concave reflecting surface, a space surrounded by the three optical free-form surfaces is filled with glass or resin optical material having a refractive index greater than 1.4, the optical surfaces include one of a spherical surface, an aspherical surface, or a free-form surface such as a complex curvature XY polynomial surface;
• light emitted from the first microdisplay enters into the first prism through the third optical surface, reflected by the first optical surface to the second optical surface, and reflected by the second optical surface and transmits through the first optical surface to the user eye.