Exposing apparatus

Abstract

In an exposing apparatus for forming a phosphor screen on the inner surface of a panel of a color cathode ray tube by exposure, a photosensitive layer is coated on the inner surface of the panel, and this panel is supported on a support table. Light rays that print a pattern corresponding to the apertures of a shadow mask are emitted from a light source unit, and the light rays are incident on a projection lens system, that guides the light rays to approximate the locus of an electron beam, through a correcting optical member. The light rays passing through the projection lens system are incident on the photosensitive layer through the apertures of the shadow mask. The correcting optical member has a light exit surface inclined with respect to its incident surface, and is rotated by a driving unit to rotate about the optical axis of the light rays, emitted from the light source unit toward the photosensitive layer, as the central axis. Therefore, the image of the light source unit is shifted by rotation, and the pattern of the aperture of the shadow mask which is close to a true circle is formed on the photosensitive layer. As a result, the landing margin can be set large, thereby manufacturing a color cathode ray tube whose color purity can be easily adjusted.