Tokyo Shibaura Electric Co., Ltd.

Hisafumi Okada

Eizaburo Hamano

Hidetoshi Yamazaki

Disclosed is an in-line type color picture tube apparatus which comprises an in-line type color picture tube including a phosphor screen for displaying a substantially rectangular picture with horizontal, vertical, and diagonal axes and an in-line electron gun arranged in parallel with the horizontal axis so as to be allowed to cast electron beams on the phosphor screen to reproduce a color image, a deflection yoke disposed around the outer periphery of the tube and generating such a magnetic field that may give positive isotropic astigmatism to the electron beams when the electron beams are deflected along the horizontal axis, may give negative isotropic astigmatism to the electron beams when the electron beams are deflected along the vertical axis, and may give negative anisotropic astigmatism to the electron beams when the electron beams are deflected along the diagonal axes, and a correction deflection element formed of a plurality of permanent magnets arranged in the vicinity of the end portion of the deflection yoke on the phosphor screen side, generating such a magnetic field that may diagonally constrict the end portions of the diagonal axes of a raster formed of the electron beams by means of an action of the deflection yoke and give positive anisotropic astigmatism to the electron beams when the electron beams are deflected along the diagonal axes. According to this in-line type color picture tube apparatus, raster distortion may be corrected practically completely without using a correction circuit, and self-convergence system may be realized.

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Kumagaya, Japan

Hisafumi Okada