Abstract: A projection lens regulator for a projection TV is disclosed to include of a base, a barrel, and an adjusting hoop. The base includes at least one guide slot positioned radially at a peripheral wall thereof. The barrel is fitted inside the base and includes at least one slope guide groove positioned radially at a peripheral wall thereof. The adjusting hoop is fitted on the base. At least one slide member is mounted on the adjusting hoop and inserted into the guide groove of the barrel through the guide slot of the base. The adjusting hoop is turned to drive the slide member to move along the slope guide groove of the barrel, and then the slide member drives the barrel to move with respect to the base axially.

Abstract: A lens assembly includes an aperture and a lens unit. The lens unit includes a first lens, a second lens, and a third lens in sequence from an object side toward an image side. The first lens is a positive lens having a concave surface that faces the image side. The second lens is a meniscus lens having a concave surface that faces the first lens and a convex surface that faces the third lens. The third lens is a non-spherical lens having two wavelike surfaces in the formation of concavity-convexity-concavity or convexity-concavity-convexity and being symmetrically formed with respect to an optical axis. The aperture is disposed behind the first lens. A coverage angle of the lens unit is ranged between 60° and 70°. Accordingly, the arrangement of the lens assembly greatly reduces the optical distortion to improve the image quality.