Matsushita Electronics Corporation

Masakazu Maeda

Kakuichiro Hosokoshi

Hiroto Nakamura

Akira Sato

In a process for exposing a photosensitive layer formed upon the inside of the faceplate of a color-picture tube so as to form a desired pattern of phosphor dots or temporary dots or the like, an optical correction system for causing the light beam to precisely impinge at a point where the electron beam impinges is interposed between a light source and a shadow mask. The system comprises an optical lens system for correcting .DELTA.S deviation characteristics and an optical lens system for correcting .DELTA.P deviation characteristics consisting of a first optical correction system and a second optical system. The first optical system is so designed as to attain the average correction depending only upon the deflection angle regardless of each of the radial directions of deflection while the second optical system is so designed as to attain the individual .DELTA.P deviation characteristics depending not only upon the deflection angle but also upon each of the radial directions of deflection. The correction lenses may have a relatively simple aspherical surface.

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Ibaraki, Japan

Masakazu Maeda