AUTOMATIC FOCUS ADJUSTING DEVICE

PURPOSE:To prevent the malfunction of automatic focus adjustment due to a random noise by providing a means which generates a control signal for moving a focus lens in a direction indicated by direction data when a specific number of the direction data indicating the same direction are counted conti...

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Bibliographic Details
Main Authors AZUMI TAKASHI, KAYANO YASUAKI
Format Patent
LanguageEnglish
Published 27.12.1990
Subjects
ACCESSORIES THEREFOR
APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USINGWAVES OTHER THAN OPTICAL WAVES
APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FORPROJECTING OR VIEWING THEM
CINEMATOGRAPHY
ELECTROGRAPHY
HOLOGRAPHY
OPTICAL ELEMENTS, SYSTEMS, OR APPARATUS
OPTICS
PHOTOGRAPHY
PHYSICS
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Summary:PURPOSE:To prevent the malfunction of automatic focus adjustment due to a random noise by providing a means which generates a control signal for moving a focus lens in a direction indicated by direction data when a specific number of the direction data indicating the same direction are counted continuously. CONSTITUTION:A far/close direction counter 13 which holds plural direction data outputs a signal indicating a rotating direction corresponding to the level of direction data when the direction data have the same level. Here, when the polarity of the integral voltage of a difference signal (A-B) is inverted owing to the mixing of a random noise, at least one of levels of the plural direction data held by the far/close direction counter 13 is affected by the random noise, so they are not equal in level and the far/close direction counter 13 does not output the signal k indicating the rotating direction of a motor. Consequently, a motor control circuit 12 stops the motor. Consequently, the malfunction due to the external random noise is precluded.
Bibliography:Application Number: JP19890132562