PURPOSE: To keep convergence in a suitable state, by distributing plural CRTs in a line and in the same direction to realize the miniaturization, and to reduce the effect of earth magnetism.

CONSTITUTION: The CRT 16 and 18 and lens systems 19 and 21 of the side part are set closer to a screen 22 than a CRT17 and a lens system 20 at the center part. So that all optical axes are coincident with each other on the center axis of dichroic mirrors 23 and 24. In such a constitution, the effect of earth magnetism is never scattered even if the installing direction is changed since the CRT16, 17 and 18 are set in a line and in the same direction. This prevents the deterioration of convergence. At the same time, the miniaturization is attained owing to the in-line distribution of the same direction with the CRTs. In addition, all projection light beams are synthesized and projected on the screen 22 through the mirrors 23 and 24. Therefore, it is not needed to provide a troublesome correcting circuit for each CRT. As a result, the circuit constitution can be simplified.