Matsushita Electric Industrial Co., Ltd.

Kazushige Kida

Kazuhiro Yamada

Takahisa Hatano

Susumu Tsujihara

Ikunori Inoue

Yoshikuni Shindo

Kazunari Yamaguchi

Hideki Abe

Noriyuki Iwakura

The invention presents a dot clock reproducing apparatus for automatically reproducing the dot clock easily, by setting the dot clock frequency of a video signal source, and correcting the phase difference of the dot clock occurring in the transmission route or the like, and also presents a dot clock reproducing method comprising, in dot clock reproduction, a step of sampling at a frequency different from the dot clock of video signal, a step of detecting the aliasing frequency component occurring at this time, and a step of reproducing the dot clock so as not to cause this aliasing frequency component, and as an apparatus employing such method, the invention further provides a dot clock reproducing apparatus comprising A/D converting means for receiving an adjusting signal delivered from a video signal source, and sampling this adjusting signal to convert into a digital signal, PLL means for dividing a specified synchronizing signal and generating a sampling clock for the A/D converting means, frequency analyzing means for analyzing the frequency of the adjusting signal from the output of the A/D converting means, and dividing ratio setting means for controlling the dividing ratio of the PLL means from the output of the frequency analyzing means, wherein the dot clock is reproduced so that the output of the PLL means may be used as the dot clock signal, thereby realizing a dot clock reproducing apparatus for reproducing automatically the dot clock easily, by setting the dot clock frequency of the video signal source, and correcting the phase difference of the dot clock occurring in the transmission route or the like.

Dot clock reproducing method and dot clock reproducing apparatus using

By providing a plurality of landing correction coil pairs each comprised of a correction coil in the x-axis direction and a correction coil in the y-axis direction at four peripheral corner portions of the cathode ray tube (CRT) and by controlling the direction and magnitude of the resultant vector of the correction magnetic fields generated by the x-axis direction correction coil and the y-axis direction correction coil, the influence of the geomagnetism is canceled to allow a high-accuracy landing correction to be achieved. Furthermore, by detecting the chromaticity and luminance information on the screen to obtain a mislanding quantity and by forming a correction current corresponding to the quantity through the aforementioned correction means to perform an automatic correction to allow a quantitative landing correction to be performed correctly in a short time.

Beam landing correction apparatus for a cathode ray tube

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Settsu, Japan

Kazushige Kida