The invention relates to a naked-eye 3D display
system based on a multi-layer
phase modulation composite
grating, belongs to the technical field of stereoscopic display, and aims to overcome the technical bottlenecks of low brightness of an existing
parallax barrier
grating, large
crosstalk caused by large thickness of a
cylindrical lens and serious dispersion of a
diffraction element. The
system comprises a two-dimensional display panel and a composite
diffraction grating, pixel units of the display panel are composed of red, green and blue sub-pixel matrixes and are coded according to
viewpoints. The composite
diffraction grating is attached to the light emitting side of the panel, is made of an optical anisotropic material and is of a multi-layer structure, and a first micro-nano structure layer and a second micro-nano structure layer are sequentially arranged along a light path; the first layer is an aspherical focusing array, and the phase
delay of the aspherical focusing array meets a quadric
surface function so as to collimate light
waves; the second layer is a
dispersion compensation type deflection array, and the grating period of the second layer is accurately matched with the central
wavelength of the sub-pixels, so that light of different colors is projected at the same
deflection angle. According to the invention, full-color dispersion-free display is realized, the thickness of the device is less than 50 microns, and
crosstalk is obviously reduced.