Projection device based on LED light source

A projection device based on LED light source, wherein the projection device comprises an LED light source, a color wheel, a light-equalizing rod, a convex lens, a first Fresnel lens, a first polarizing plate, an LCD panel and a projection lens, the first polarizing plate is positioned between the first Fresnel lens and the LCD panel;

• a ray of target light emitted by the LED light source emits a target alternating light through the color wheel, and the target alternating light comprises five monochromatic lights, the monochromatic lights comprise red light, green light, blue light, yellow light and white light, and the five monochromatic lights enter the light-equalizing rod for uniform treatment to emit an uniform light spot, the uniform light spot is imaged at the first Fresnel lens through the convex lens, then irradiated into the LCD panel, and projected by the projection lens;
• the projection device further comprises a grating arranged between the first polarizing plate and the LCD panel, the grating is configured to properly refract an incident light from the first polarizing plate and enter an corresponding area of the LCD panel at a desired angle.