초록 ▼

Apparatus for use with an autofocus adjusting device which has a focus detecting circuit for detecting a focus state of an imaging optical system, and a driving circuit for driving the imaging optical system in accordance with the detected focus has a calculation circuit for performing a first calcu

Apparatus for use with an autofocus adjusting device which has a focus detecting circuit for detecting a focus state of an imaging optical system, and a driving circuit for driving the imaging optical system in accordance with the detected focus has a calculation circuit for performing a first calculation in which imaging plane positions at a plurality of points of time in the past and in the present time are determined on the basis of a signal representing a focusing state in the past and a signal representing a focusing state at the latest time to determine coefficients of a predetermined higher order function. The calculation circuit also performs a second calculation in which an imaging plane position at a time after a predetermined period of time has past is determined on the basis of the higher order function. A regulation circuit regulates the signal representing the focusing state detected by the focus detecting circuit when the second calculation is performed, and causes the second calculation to be performed on the basis of the regulated signal. A control circuit is provided for transmitting the signal representing the imaging plane position obtained by the calculation circuit to the driving circuit for driving the imaging optical system. This allows proper focus point prediction even when the zoom state of a zoom lens changes.

대표청구항 ▼

Apparatus for use with an auto focus adjusting device which is provided with a focus state detecting circuit for detecting a focusing state of an imaging optical system and a driving circuit for driving the imaging optical system n conformity with a result of the detection by said detecting circuit,

Apparatus for use with an auto focus adjusting device which is provided with a focus state detecting circuit for detecting a focusing state of an imaging optical system and a driving circuit for driving the imaging optical system n conformity with a result of the detection by said detecting circuit, comprising: (a) a calculation circuit for performing a first calculation in which imaging plane positions at a plurality of points of time in the past and at the present time are determined on the basis of a signal representing a focusing state in the past detected by said focus state detecting circuit and a signal representing a focusing state at the latest time to determine coefficients of a predetermined higher order function, and for performing a second calculation in which an imaging plane position at a time after a predetermined time has passed is determined on the basis of the higher order function: (b) a regulation circuit for regulating the signal representing the focusing state detected by said focus detecting circuit, and for causing the operation of said calculation circuit to be performed on the basis of said regulated signal; and (c) a control circuit for transmitting the signal representing the imaging plane position obtained by said calculation circuit to said driving circuit for driving said imaging optical system.