Systems and methods for multiplying the image resolution of a pixelated display

An apparatus for multiplying display resolution, the apparatus comprising:

• an image projector for directing light from pixels of a pixelated image source into unique angular directions wherein the image projector comprises a microdisplay panel optically connected to a projection lens and wherein the pixelated image source produces a native image and at least one shifted image;
• an image processor electrically connected to the image projector for computing the native image and the at least one shifted image in a predefined direction for sequential display by the image projector;
• and
• at least one switchable grating disposed within a waveguide and switchable between diffracting and non-diffracting states optically coupled to the image projector, wherein the at least one switchable grating have a first configuration for propagating the light of the native image and at least one configuration for propagating the light of the shifted image with an angular displacement corresponding to the image shift in the predefined direction, wherein the at least one switchable grating comprises first and second gratings disposed in a first waveguide and third and fourth gratings disposed in a second waveguide, wherein the first grating overlaps the third grating and the second grating overlaps the fourth grating, wherein the first and third gratings act as input couplers and the second and fourth gratings act as output couplers, wherein the first configuration is provided when the first and second gratings are in their diffracting states, and wherein the second configuration is provided when the first and second gratings are in their non-diffracting states.

A method of multiplying the resolution of a waveguide display, the method comprising:

• providing an image projector and an image processor;
• providing a waveguide containing first, second, third and fourth switchable gratings with the first and third gratings substantially overlapping and the second and fourth gratings substantially overlapping, wherein each grating have an optical prescription for applying an angular shift to incident light;
• selecting pixel shift (N+½) multiplied by P, where N is an integer greater than or equal to zero and P is a pixel dimension;
• computing a shifted image using the image processor;
• writing a shifted image to the image projector;
• switching one of the first and third switchable gratings and one of the second and fourth switchable gratings into their diffracting states;
• coupling shifted image light into the waveguide via the diffracting first or third switchable gratings;
• coupling image light out of the waveguide via the diffracting second or fourth switchable gratings with a pixel shift determined by the prescriptions of the diffracting switchable gratings.