Canon Kabushiki Kaisha

Hideto Iwama

Masamichi Toyama

Hidekazu Okajima

Toshikazu Ichiyanagi

Mamoru Shimazaki

Noritsugu Hirata

Tomoshi Takigawa

Akimasa Nishimura

Kazuo Ishikawa

A motion picture camera provided with an automatic focusing device is arranged to have an image of light emitted from an infrared ray emitting diode projected toward an object to be photographed, and to detect an in-focus state by detecting a peak value of output voltage from a light sensitive element as the direction of the emitted light is varied by a rotatable distance measuring cam. The automatic focusing device is adapted for a zoom lens assembly and is arranged to drive an imaging lens, supported by a shaft which is guided by plate shaped masks at both ends of the lens assembly, in the direction of the lens optical axis. The force for driving the imaging lens is kept low, so that the imaging lens can be accurately adjusted by a rotatable focusing cam during a focusing operation. The rotational position of the distance measuring cam, and that of the focusing cam, are provided in the form of resistance values which vary according to the cam lifts, or in the form of digital codes. When digital codes are employed, distance intervals are established so that the depth of field at each interval overlaps an adjacent interval. Satisfactory focusing thus is provided for all distances within any measured interval.

Motion picture camera with automatic focusing device

The present invention relates to a camera having an automatic focus adjusting device, being characterized in that the motor for the focus adjustment is not provided particularly, whereby the motor for the shutter operation and the film feeding is changed over by means of a clutch so as to be used for the focus adjustment.

Camera having an automatic focus adjusting device

In the disclosed motion picture system a shutter drive control circuit renders it possible to operate a rotary shutter in various exposure control modes including a mode in which rotation of the shutter is stopped for each long exposure of motion picture frame, the system can defer release of the shutter to the exposure aperture closed position pending completion of a picture frame exposure in any of the modes. The system terminates the preceding manual actuation of a shutter trigger when the taking of the particular picture frame is in progress.

Motion picture system

In the disclosed automatic exposure control device for a motion picture camera and so on, a diaphragm driving arrangement drives a diaphragm arrangement. An exposure control arrangement having a light sensing element for sensing scene light and producing an electrical output corresponding to the scene brightness, controls the diaphragm driving arrangement on the basis of the output of the light sensing element, the sensitivity information of the film to be used and so on, so that a proper exposure can be obtained. A diaphragm presetting arrangement electrically controls the diaphragm driving arrangement independently of the exposure control arrangement to set the diaphragm arrangement at an intermediate opening position. A selector normally disables the control of the diaphragm driving arrangement by means of the exposure control arrangement and enables the control of the diaphragm driving arrangement by arrangement of the diaphragm presetting means. However, in response to the operation of the camera release, enables control of the diaphragm driving arrangement by the diaphragm presetting arrangement, and enables the control of the diaphragm driving arrangement by means of the exposure control arrangement. In consequence, before the camera as been released the diaphragm arrangement is always preset at the intermediate open position by means of the diaphragm presetting arrangement. Hence even when the brightness of the object to be photographed is very low, the response delay of the light sensing element is improved in and at the time of camera release and the diaphragm arrangement is quickly adjusted to a position for producing giving a proper exposure with the exposure control means.

Automatic aperture presetting and exposure control device for camera

A motion picture camera provided with a device which ensures satisfactory film exposure by cutting off unnecessary electric power supply to an electrical circuit of an information indicating lamp or the like in response to a camera setting action made to allow the camera to operate even after the operator thereof moves away from the camera.

Motion picture camera

A light metering system for a photographic camera which may be selectively operated in a through-the-lens (TTL) light metering mode or an outside-the-lens (OTL) light metering mode to improve the exposure control accuracy over an extended range of light levels particularly towards the low light level side. In one embodiment, the light metering system employs a single light value sensing element in combination with light path changeover means arranged upon movement to change over the light metering aspect between the TTL and OTL light metering modes. In another embodiment, there is provided two light value sensing elements of different light response characteristics from each other for adaptation to the respective light metering modes in combination with a circuit transfer switch operable to select either the TTL light metering mode or the OTL light metering mode. With a camera equipped with a shutter preselection automatic exposure control range and a diaphragm preselection automatic exposure control range, it is possible to realize suitable combinations of the exposure control modes with the light metering modes.

Light metering system for a photographic camera

A self-timer for cinecameras wherein an electric delay circuit is used for detecting a length of time from the release to the commencement of a photographing process which takes place with an electric power having been actually supplied to a film feeding motor. The amount of the rotation made by the film feeding motor from the start of the rotation of the motor is either mechanically or electrically detected. When the detected amount of rotation reaches a preset value corresponding to a number of frames of the film required for self-timer photographing, the motor is stopped to terminate the photographing operation, so that the photographing operation with the self-timer can be accomplished exactly for a preset number of frames.

Self-timer

An automatic exposure control system for controlling the diaphragm of a motion picture camera in accordance with the object brightness level photoelectrically determined from the amount of light passing through the diaphragm is provided with a manually switchable shutter control device having a number ofswitched positions including positions for selection of various speeds of rotation of the camera shutter and for selection of various shutter intervals each effected in one revolution of the shutter in combination with a corresponding number of branch circuits of the exposure metering device controlling operation of the camera diaphragm, whereby it is made possible to make exposures not only at normal light levels but also at low light levels outside the lower limit of the normal light level range.

Exposure control system and a motion picture camera using the same

A self-timer device for a motion picture camera of the type having a first motor for driving a film feeding device and a shutter device and a second motor for driving other moving parts such as a zoom lens system. In the device, automatic photographing controlling means which is provided with cam portions for controlling the timing for starting and stopping the camera release operation is operated by the second motor. For photographing, an interlock arrangement between the second motor and the other moving parts which are to be driven by the motor is released while, at the same time, the cam portions of the controlling means are brought into a given relation to a camera release arrangement. This is done in such a manner that the timing for starting and stopping the camera release, i.e. the time intervals between setting for automatic photographing and the actual commencement of it and between the start of photographing and the end of it, is controlled by the cam portions of the controlling means as the controlling means is operated by the second motor to accomplish an automatic photographing operation.

Growing community of inventors

Kawasaki, Japan

Hideto Iwama