PURPOSE: To rationalize production by making the optical axis of projection lens of a projection tube in which the optical axis of the projection lens is inclined eccentric against a screen and the optical axis of the projection tube against the optical axis among three projection tubes of blue, green and red.

CONSTITUTION: When the eccentric amount of the optical axis of the projection tube and the optical axis of the projection lens is set to be δ, it is assumed that δ=Rsinβ, where tanβ=(n/m)tanθ, R= curvature of projection tube surface, m= magnification of projection lens, n= cooling liquid refractive index, θ= screen incident angle. Since both optical axis are made eccentric by δ, an action similar to that for inclining the optical axis of the projection lens 20 by a scheinpflug angleβ against the optical axis of the projection tube is generated. The trapezoidal distortion of a video can be corrected and focusing can be executed on the whole screen. Since the size of the screen of the projection television is changed, only the eccentric amount making a coupler eccentric to right and left is changed when a distance from the projection tube to the screen is changed, and it is not required to newly generate the coupler.