Projector in a projection television

摘要

A liquid cooling type projector is provided with greater flexibility to meet different screen sizes of a projection television and, thus, contributes to the reduction of production cost. The projector has a cylindrical frame containing a projection lens unit mounted by a liquid-tight member thereto and coupled at a rear end to a CRT in liquid-tight arrangement such that a liquid-sealing space is established between the projection lens and the CRT. In particular, the projection lens unit is arranged so as to be movable with respect to the frame along its optical axis. Also, the liquid-tight member is arranged to maintain the liquid-tight condition regardless of the position of the projection lens unit relative to the frame. Thus, the projection lens unit can arbitrarily be displaced towards and away from the CRT, increasing a focusing range. Accordingly, the projector will successfully be matched to different sizes of projection screens contributing to the reduction of the production cost of projection televisions.