PURPOSE: To extend the distance between a lens and a video tube sufficiently and to eliminate the evil influence of temperature variation by employing the three-group, three-element of the 1st positive lens having aspherical surfaces as both surfaces, the 2nd biconvex glass lens, and the 3rd negative lens having spherical surfaces as both surfaces, and satisfying specific inequalities.

CONSTITUTION: The lens system has the three-group, three-element constitution, i.e. consists of the 1st lens L1 which has aspherical surfaces as both surfaces while having a surface with larger curvature on a screen side, the 2nd biconvex lens L2, and the 3rd lens L3 which has aspherical surfaces as both surfaces and a larger-curvature surface on the screen side, and the surface interval between the 2nd lens L2 and the 3rd lens L3 is made shorter than before so as to obtain necessary distance between the lens and video tube. Plastic lenses are used as the 1st and the 3rd lenses L1 and L3, and glass lens is used as the 2nd lens L2. Further, inequalities I WV hold to realize the image projection lens which causes no misconvergence.