Patent ID: 10764547

Abstract:
A projection system projects images onto a projection surface in, for example, a computer game head-mounted display (HMD). The light is projected through a spatial light modulator that is combined with a Freeform Fourier Lens that is a combination of a Fresnel lens, an X-phase grating, a Y-phase grating, and a radial grating. The freeform lens causes the gradual shrinking of portions of the laser-projected image, decreasing the perceived pixel pitch in at least one foveal area on the projection surface compared to a non-modulated laser image. The center positions of the Fresnel lens and radial grating can be changed in the X and Y axes, moving the condensed foveal areas in accordance with eye tracking of the user. In effect, the system projects a Foveated image that contains variable pixel pitch such that a user perceives a higher visual acuity in his gaze direction.