Minolta Camera Kabushiki Kaisha

Hidenori Fukuoka

Masatoshi Itoh

Takashi Iida

Kazuhiko Kojima

Takeya Tsukamoto

Masataka Hamada

Hiroshi Ootsuka

Kenji Ishibashi

Takashi Kondo

Toru Ishii

Daigo Yoshioka

Hiroyuki Tsumazawa

Atsushi Kuwada

An in-focus detection apparatus used for a video camera includes edge width detector for detecting a plurality of edge widths of an object, and an calculation device for calculating the amount of driving a lens based on the distribution state of these plurality of edge width data. The apparatus uses a video signal and provides the in-focus state of an actual object with a high accuracy without requiring slight movement of a focusing lens.

In-focus detection apparatus using video signal

An automatic focusing apparatus according to the present invention comprises a photo-taking lens system, in which a focus has to be adjusted every time the focal length is changed, including at least a first lens unit for changing the focal length by means of its movement along an optical axis of the photo-taking lens during the zooming operation and a second lens unit for adjusting the focus by means of its movement along the optical axis, and a controller for controlling the speed of the second lens unit during the zooming operation based on the focal length of the photo-taking lens system, the lapse of the time related with focus detection cycles, the reliability of the result of the focus detection and so on.

Camera having a zoom lens unit

The disclosure relates to an automatic focusing apparatus for use in a photographic camera and, in a particular video-camera. The apparatus includes a defocus amount detecting device such as charged coupled devices (CCD) array for detecting the defocus amount of a photographic lens, a memorizing device for memorizing the focusing zone to carry out the lens-focus-adjustment, a comparing device for comparing between the specific setting value and the detected defocus amount, a selecting device for selecting the focusing zone so as to carry out the lens-focus-adjustment in accordance with a detection of the focusing condition, a focus adjusting mechanism for carrying out the lens-focus-adjustment on the basis of the defocus amount of the focusing zone selected by the selecting device, and a focusing zone alteration device for rememorizing the focusing zone with respect to the change of the focusing zone at which the lens-focus-adjustment is carried out. The displacement of the defocus amount corresponding to the change of a relative location of the object to the photographic lens is approximately proportional to the displacement of the output signal of the defecting device of the defocus amount, so that it is possible to know by detecting the defocus amount whether or not the photographic lens is properly focused and where the object is located in a photographic field if not focused.

Automatic focusing apparatus

A focus detection condition display device suitable for use in a camera provided with an electronic viewfinder. The pattern signal corresponding to a focus detection zone on which focus detection is conducted by a focus detecting system is superimposed on the video signal of the object field and said signal is output to an electronic viewfinder. When the focus detection has become impracticable for such reason as lack of contrast of the object field, or focusing has become impracticable because of the object coming too close to the camera, an alarm is issued by the pattern corresponding to a focus detection zone displayed on the electronic viewfinder displaying in a manner different from that ordinarily used.

Focus detection condition display device for camera

When a teleconverter is attached, the variator is once moved to the tele end regardless of its position. Thereafter, by the input of zoom operation key, the movement of the variator to the wide side, namely zooming, becomes possible with the range of movement automatically limited in a prescribed range in order to prevent shading due to the attachment of the teleconverter. Meanwhile, if a wide converter is attached, the variator is similarly moved to the wide end. Thereafter, the movement of the variator is prohibited regardless of the presence/absence of the input of the zoom operation key. When the teleconverter or the wide converter is detached, the limit of the range of movement or prohibition of the movement of the variator is cancelled and usual zooming operation is retrieved.

Camera having a converter-attachable zoom lens

When a variator lens is driven to effect zooming, focal length information of a zoom lens unit, a zooming direction and a defocus amount are detector. Integration in CCD for focus detection is regulated in a short time during zooming and a cycle of focus detection is set to a predetermined period. A moving speed of a compensator lens is controlled based on detected information. A moving range of the variator lens is divided into zones and a basic moving speed of the compensator lens is set for each zone. When the variator lens is driven and information obtained by focus detection or a zooming condition corresponds to a specified condition, the compensator lens is moved at a basic speed corresponding to the zone where the variator lens exists or at a moving speed of the compensator lens applied till then. Focus detection areas automatically changed dependent on a situation of an object are forbidden to be changed during zooming. In addition, a focus detection are indicating mark displayed in a finder of the camera is fixed and unchanged during zooming irrespective of actual change of the focus detection area.

The present invention relates to a white balance adjusting device for a color video camera for photographing an object irradiated by light from a blackbody radiation source or a non-blackbody radiation source. When recording operation is being performed, the white balance adjusting device prevents the moving operation of a fluorescent light correction filter and a color temperature conversion filter into an optical path of image pickup means and permits a white balance adjustment operation performed by electrically correcting an output of the image pickup means. When a recording operation is not being performed, the white balance adjusting device permits the moving operation of the fluorescent light correction filter and the color temperature conversion filter into the optical path and permits white balance adjustment operation performed by electrically correcting the output of the image pickup means.

White balance adjusting device for a color video camera

A camera such as a vide camera having an automatic focusing function, a power focusing function and a power zooming function which allows most reasonable change-over between the functions of the camera. The camera comprises manually operable mode change-over means for alternatively changing over the camera between a zooming mode and a focusing mode, and manually operable instructing means for instructing a direction of movement of a zooming lens system or a focusing lens system for zooming or focusing. When the zooming mode is selected, first actuating means actuates the zooming lens system for zooming in a direction instructed by the instructing means, but when the focusing mode is selected, second actuating means actuates the focusing lens system for focusing operation in a direction instructed by the instructing means. Several forms of instructing means are disclosed.

Growing community of inventors

Osaka, Japan

Hidenori Fukuoka