Canon Kabushiki Kaisha

Taeko Tanaka

Kitahiro Kaneda

Hiroto Ohkawara

Tatsuya Yamazaki

Masahide Hirasawa

Hirofumi Takei

Seiya Ohta

Hitoshi Yasuda

It is an object of this invention to provide an image sensing method which allows object focus tracking during zooming regardless of the shutter speed. In order to achieve this object, a zoom motor for driving a zoom lens is controlled by a lens control microcomputer to decrease the zoom speed.

Image sensing method, image sensing apparatus, lens control method therefor, and storage medium

An automatic focusing device includes an extracting circuit which extracts a focus signal corresponding to a degree of focus from a picked-up image signal, a focusing lens and a direction deciding circuit which decides the direction of driving the focusing lens on the basis of the output of the extraction circuit when the state of focus deviates from an in-focus state. The extracting circuit is arranged to simultaneously extract a plurality of focus signals having different frequency components from each other. The direction deciding circuit is arranged to perform computing operations on the focus signals separately from each other with respect to the focusing lens driving direction and to decide the focusing lens driving direction when the results of the computing operations come to coincide with each other.

Automatic focus adjusting device

A video camera having a variator lens and focus lens which calculates in-focus positions varying with the drive of the variator lens based on previously stored in-focus position data, and performs the calculation a plurality of times during a period of a vertical-synchronizing signal in an image signal.

Lens control apparatus, lens control method, and video camera having same

A lens control device comprising a variator lens, a compensation lens for compensating for the displacement of the focal plane associated with the movement of the variator lens, a conversion lens disposed in an optical path in a detachable manner for limiting the area of the movement of the variator lens, and correction means for modifying the area of the movement of the compensation lens in response to the mounting of the conversion lens.

Lens control device for moving range correction

An image pickup apparatus capable of performing shooting action control appositely to each of different modes of shooting such as moving image shooting and still image shooting includes an instructing part for selectively instructing the apparatus to perform moving image shooting or still image shooting, and a control part for variably setting control characteristics for various control actions such as backlight correction control, white balance control, automatic focusing control, shutter speed control, etc., according to the instruction of the instructing part.

Apparatus for still and moving image recording and control thereof

An image pickup apparatus includes a first mode for picking up an image of a subject located at a close distance and a second mode for performing normal photography, and is arranged to vary the moving range of a variator lens and/or the characteristics of an automatic focus adjustment device during the first mode.

Apparatus for picking up images of photographed and unphotographed subjects

A lens control device comprising a variator lens group for zooming, a focusing lens group for compensating for a change introduced into the focused position as a result of a zooming operation by the variator lens group, a conversion lens group for changing a focusable shifting area of the variator lens group from a first area to a second area, a computing circuit for determining driving information for driving the focusing lens group during the shifting of the variator lens group, based on focused position data, according to object distance, of the focusing lens group relative to the position of the variator lens group, and a control circuit for shifting the variator lens group from the first area to the second area in response to the mounting of the conversion lens group and for controlling a computing operation of the computing circuit so that a focused position of the focusing lens group is determined when the variator lens group moves within the second area.

Lens control device with AF restart feature

Automatic focus adjusting device with driving direction control

Lens control apparatus

A lens control apparatus includes a lens, a counter which indicates a driving position of the lens, and a control part which initializes a count value of the counter every time the lens passes a predetermined reference position during an image pickup operation.

A lens control apparatus drives a lens with a sine wave by means of a pulse motor and detects the position of the lens by counting the number of pulses during the driving of the pulse motor, and stores a stop phase which is reached by a rotor when the pulse motor is brought to a driving-stopped state. When the lens control apparatus is to move the lens to an initial position and initialize a counter for detecting the position of the lens, the lens control apparatus corrects the count value of the counter by using information indicative of the stored stop phase of the rotor.

A focus control apparatus comprises a first detector for detecting a focus state of an object image formed on an image screen, a second detector for detecting a dispersion (degree of spread) of an eye point of a photographer on the image screen, and a control unit for controlling the focus state using outputs from the first and second detectors.

Image pickup apparatus using eye point dispersion in focus control

A lens control apparatus which corrects a variation in a focus position due to a zooming operation by driving a compensator lens at a standard speed according to a predetermined cam locus is arranged to determine a correction direction on the basis of an integral value of a high-frequency component and a correction speed on the basis of the ratio of the high-frequency component to a luminance difference, and to combine the correction speed based on the state of focus with the standard speed.

An automatic focusing device includes an image pickup device for outputting an image signal by performing photoelectric conversion of an image of an object, a band-pass filter for extracting a sharpness signal corresponding to the sharpness from among the image signal, a diaphragm for controlling the amount of light incident upon the image pickup device, and a control circuit for controlling prohibition of the drive of a focusing lens based on a change in the sharpness signal output from the band-pass filter and a change in the state of the diaphragm. It is thereby possible to exactly detect an operation, such as panning or the like, and to prevent the stop of the focusing lens at a defocused position caused by an erroneous operation by prohibiting the drive of the focusing lens when panning has been detected.

Automatic focusing device capable of detecting panning

A lens control device includes a variator lens for zooming, a focusing lens for compensating for a focus plane position change associated with the variator lens' movement, a conversion lens for modifying the focal length determined by the variator lens, a driver for driving the variator lens and the focusing lens, and a control circuit for changing a driving speed of the variator lens between when the conversion lens is mounted and when the conversion lens is not mounted.

Growing community of inventors

Kanagawa-ken, Japan

Taeko Tanaka