Canon Kabushiki Kaisha

Hiroto Ohkawara

Masahide Hirasawa

Tatsuya Yamazaki

Hirofumi Suda

Taeko Tanaka

Toshimichi Kudo

Kenji Kyuma

Toshinobu Yamaguchi

A video camera includes a gate circuit for extracting a sharpness signal relative to an area which is set in a portion of a picture, a focus adjusting device for performing focus adjustment on the basis of the sharpness signal relative to the area, and an area selecting circuit for controlling the gate circuit to vary the area in size and determining a size of the area during a driving of a variator lens in accordance with a size of the area and a focal length used before the driving of the variator lens.

Video camera apparatus including automatic focusing

In order to be able to reduce power consumption while making possible manual operation in any scene when the photographic situation demands its use, an image pickup apparatus has a ring member arranged concentrically with the optical axis of lenses, a detecting device for detecting the quantity of variation resulting from the rotation of the ring member, a control device for shifting/stopping a group of optical lenses in the direction of their optical axis on the basis of the result of detection by the detecting device, and a power supply control device for changing the state of power supply to the detecting device according to the mode of use. Power supply to the detecting device is prohibited when in the automatic focusing mode, and permitted in a focusing-locked state when in the photo shooting mode. It is also prohibited in the viewing mode.

Image pickup apparatus and power supply control method therefor

In an interchangeable lens assembly video camera system including an interchangeable lens assembly and a camera, a filter of an AF signal processing circuit () of the camera extracts a focus evaluation value signal from an image sensing signal corresponding to one or a plurality of focus detection areas in an image sensing surface, and on the basis of the transmitted focus evaluation value signal from the camera and data stored in a ROM (), the microcomputer () performs a zooming operation of a zoom lens () while maintaining an in-focus state of a focus lens ().

Interchangeable lens video camera system

A lens control apparatus and an image pickup apparatus each of which, during a magnification varying operation in an inner focus type of lens system, predicts a destination position to be reached by a variator lens after a predetermined time period, calculates a speed at which to move a focusing lens to a correction position of a focal plane relative to the predicted position of the variator lens, and controls the focusing lens.

Image pickup apparatus with focusing lens control device

A video camera system having a camera () and an interchangeable lens assembly () attachable to and detachable from the camera. A distance measurement frame is set by a distance measurement frame controller () on photographer's line-of-sight position information detected by line-of-sight detecting units (to), and a focal-point evaluation value is extracted by an AF signal processing circuit () from an image signal corresponding to the distance measurement frame. The line-of-sight position information, focal-length evaluation value, etc, are transmitted to the lens assembly (). A zoom lens () and focusing lens () are controlled by the lens assembly ().

Video camera system with interchangeable lens assembly

An automatic focus adjusting device in which a distance measuring area is set from a plurality of distance measuring areas including a first distance measuring area and a second distance measuring area which differs in size from the first distance measuring area. A state of focus is discriminated in a distance measuring area before a focus adjusting operation is started by driving an optical element for focus adjustment when the optical element is in an in-focus state, and on the basis of the discrimination, a distance measuring area to be used after the focus adjusting operation is started is selected from the first distance area and the second distance area.

Automatic focus adjusting device with distance measuring area selection based on discrimination of a state of focus

An image sensing apparatus having a function of correcting vibration of an image limits operation of a vibration correction unit in correspondence with the ratio of the correction amount as an output from the vibration correction unit to the maximum correction range of that unit.

Image vibration prevention apparatus

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 has a lens unit detachably mounted on a camera body. A zoom ring is rotatably arranged on the lens unit. A magnification varying action of a zooming lens is controlled by a lens microcomputer according to the rotation of the zoom ring detected by a rotation detecting circuit. The magnification varying action can be controlled also by a camera-body microcomputer according to the operation of a zoom switch disposed on the side of the camera body. The magnification varying action by the zoom ring has priority over the magnification varying action by the zoom switch.

Lens control device with operator and signal control

An interchangeable lens video camera system which can stably focus on a main target object under any conditions of the object or the environment. The camera system includes a lens assembly detachably attached to a camera for photoelectrically converting incident light to sense an image and output an image signal. The camera system further includes a zoom lens and a focus lens controlled on the basis of an automatic focus evaluation value and data associated with exposure which are received from the camera while referring to a lens cam data unit which stores locus information of the zoom lens and the focus lens in advance. The interchangeable lens video camera system allows for the reduction of blurring and degradation of image quality.

Interchangeable lens video camera system having improved focusing

Apparatus for improving image vibration suppression

Image pickup apparatus with lens control apparatus and focusing lens control

In an interchangeable-lens type camera to which a lens unit is removably secured, information relative to the amount of variation per unit time of the focal length of the magnification varying lens of the lens unit is transmitted from the lens unit to a camera-body side, and zoom control is performed on the camera-body side on the basis of such information.

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Toride, Japan

Hiroto Ohkawara