Nikon Corporation

Nippon Kogaku K.k.

Hiroshi Meguro

Toru Kosaka

Tadashi Otani

Sakuji Watanabe

Naoto Inaba

Tsugio Takahashi

Hitoshi Aoki

Yoshiaki Ohtsubo

Nobuo Okabe

Nobuhiko Terui

Yuji Okubo

Takashi Tanemura

A laser drive circuit for modulating a laser beam intensity emitted from a laser device to a maximum power and a minimum power in accordance with a first and second values of a binary signal comprises: a photo-detector for detecting the laser beam emitted from the laser device to produce a detection output signal; a first differential amplifier for producing a maximum error detection signal representing a difference between the detection output signal applied thereto and a maximum reference; a second differential amplifier for producing a minimum error detection signal representing a difference between the detection output signal applied thereto and a minimum reference, a first sample and hold circuit for sampling and holding the maximum error detection signal at a timing of the first value of the binary signal and outputting the same as a maximum error signal; a second sample and hold circuit for sampling and holding the minimum error detection signal at a timing of the second value of the binary signal and outputting the same as a minimum error signal; and a laser drive amplifier for controlling the maximum power and the minimum power of the laser beam emitted from the laser device in accordance with the maximum error signal and the minimum error signal.

Laser drive circuit with independently adjustable maximum and minimum

Laser drive circuit

In a camera system including an electronic flash apparatus, a main capacitor of the flash apparatus is charged for a predetermined time interval, in response to a preparatory operation such as a first stroke of a release button. During this time interval, operation of an automatic distance measuring device, an automatic exposure controlling device and an object luminance discriminating circuit is prevented. A warning device warns a photographer that the main capacitor is insufficiently charged. Several voltage detectors detect different voltage levels of the main capacitor and produce detection signals for inhibiting the operation of the warning device and/or preventing further charging of the main capacitor.

Electronic flash apparatus for cameras

A lens shutter camera comprises a mode signal output device for outputting either a first flash mode signal or a second flash mode signal, a shutter driving device for effecting the opening movement of the lens shutter slowly and effecting the closing movement of the lens shutter quickly when the first flash mode signal is being outputted, and for effecting both of the opening and closing movements of the lens shutter slowly when the second flash mode signal is being outputted, and a flash start signal output device for outputting a flash start signal during the opening movement of the lens shutter when the first flash mode signal is being outputted, and for outputting the flash start signal during the closing movement of the lens shutter when the second flash mode signal is being outputted.

Flash taking lens shutter camera

A distance-measuring apparatus comprises a first detecting device for detecting a distance to a central portion of an object field corresponding to a photographing frame and generating data corresponding to a detected distance, a second detecting device for detecting distances to a plurality of peripheral portions of the object field except for the central portion and generating data corresponding to detected distances, and an operating device for operating the first and second detecting devices. The oeprating device has a first operation step of operating the first detecting device and a second operation step of operating the second detecting device. The first step is executed to determine the detected distance to the central portion. The execution of the second step depends on the determination result and may produce an average peripheral distance output or a shortest peripheral distance output for driving a phototaking lens. Depending upon the determination result, a central distance output may instead by produced.

Distance-measuring apparatus for camera

There is disclosed a zooming control device for a camera, enabling photographing with a constant magnification of an object, and still avoiding overflowing of an object from the photographed frame in zooming of the lens. The frame is divided into plural areas, and there is discriminated whether an object is present only in the central area, or also in the peripheral area or areas. In the former case the lens is zoomed to achieve a preset image magnification, but, in the latter case, the zooming is limited in order to avoid overflowing of an object from the frame.

Zooming control device for camera

An exposure control apparatus of a camera comprises exposure control device adjusted to control the quantity of light applied onto a photosensitive film, a device for preparing a photometering output responsive to the quantity of light from an object to be photographed, the preparing device effective to prepare on the basis of the photometering output a first output used to adjust the exposure control device so that the quantity of light applied onto the film is proper, a device for setting the exposure amount by manual operation, the setting device being effective to prepare a second output used to adjust the exposure control device so that the set exposure amount is obtained, selecting device having a first selecting position for making the first output effective and a second selecting position for making the second output effective, in order to adjust the exposure control device, and operating device operated to store the photometering output, the operating device including change-over means operated when the selecting device is in the second selecting position to thereby act on the selecting device and make the first output instead of the second output effective.

Exposure mode setting device in an exposure control apparatus of a camera

A lens structure with an imaging optical system detachably mountable on a camera body having a focus detecting device capable of detecting the positional relationship between the image of an object formed by the imaging optical system and a predetermined plane and of producing a corresponding detection signal comprises means for adjusting the imaging optical system in response to the detection signal, terminal means to be electrically connected to the camera body upon mounting of the lens structure on the camera body and detecting means adapted to transmit, to the camera body, a first signal in a first state where the imaging optical system is focused to the object at infinite distance, or a second signal in a second state where the imaging optical system is focused to the object at a shortest distance, or a third signal in a third state other than said first or second state.

Automatic focusing camera system and photographing lens structure

In a camera having a phototaking lens capable of manual focusing operation by an operating ring and automatic focusing operation by a drive control device responsive to the output of an in-focus detecting device and wherein the manual focusing operation and the automatic focusing operation can be selectively accomplished by means of a change-over operating device, there are provided display means capable of displaying information on the in-focus condition of the phototaking lens in response to the output of the in-focus detecting device, focus lock means operable to restrain the movement of the phototaking lens at any position related to the focusing operation of the phototaking lens and at the same time fix the display by the display means, and means for blocking the operation of the focus lock means in response to the selection of the manual focusing operation by the change-over operating device.

Growing community of inventors

Kawasaki, Japan

Hiroshi Meguro