Canon Kabushiki Kaisha

Texas Instruments Corporation

Other

Yoshiyuki Takishima

Masanori Uchidoi

Hiroshi Aizawa

Masami Shimizu

Nobuaki Date

Tadashi Ito

Tetsuya Taguchi

Takao Kinoshita

Tokuichi Tsunekawa

Susumu Kozuki

Yukio Mashimo

Stephen C Kwan

Bernhard H Andresen

Zenzo Nakamura

Yukio Iura

Robert C Martin

Tatsuya Taguchi

Tokuichi Tunekawa

David Fullagar

An electronic camera electronically records an optical image by using a non solid-state memory and includes an image pickup element, an image pickup section, and an external recording section. The image pickup section includes a solid-state memory means for digital-recording at least one-frame image signals supplied from the image pickup element. The external recording section includes a non solid-state memory means, and a D/A converter for analog-recording a digital image signal supplied from the image pickup section on the non solid-state memory means. The image pickup section and the external recording section are detachable.

Electronic camera

A camera detects which of a number of operating modes is dialed into a flash unit by sensing the current level produced by a source. In response to dialing of a daylight EE mode, the camera measures the brightness of the object to be photographed and conforms the diaphragm aperture to a preselected shutter speed. In one flash mode the flash unit transmits desired aperture and shutter speed data suitable for flash and the camera automatically responds. In another mode, the shutter speed is set into the camera and the camera automatically controls the diaphragm aperture on the basis of data transmitted by the flash unit.

Photographic mode selector system

A storage device for storing photographic exposure information employs a closed-loop analog-to-digital (A-D) converter circuit includes a counter and a digital-to-analog (D-A) converter. The influence of erroneous signals which are created at the output of the D-A converter when the exposure information is stored in the counter is eliminated. The D-A converter circuit employs a ladder network of coarse accuracy. The stored exposure value, however, is highly accurate because of the closed-loop nature of the A-D converter circuit. Means responsive to the stored value for operating the exposure system of the camera are disclosed.

Exposure information storage device for a photographic camera

In the camera disclosed, a light measuring device and input data setting device establish exposure control signals which regulate exposure elements. When the control signal is out of range of an element, a switch turns on an adjusting arrangement which resets the setting device. The setting device may preset an element such as the aperture or shutter.

Exposure adjusting device for camera

The present invention relates to a camera having an exposure control device designed so that the light measurement, the exposure condition determination and the photographing operation are carried out by means of a release means including an electromagnet element to be controlled by means of a plural number of switches operating successively with the release operation of the camera. The invention is characterized in that the time at which the output signal of the control circuit for controlling the operation of the camera after the light measurement in accordance with the magnitude of the output signal of the light measuring means is controlled so as to be delayed in such a manner that a correct operation can be obtained even if the light measuring time is short.

Camera having a release control device

A camera which permits change-over between different light measuring systems is disclosed. The camera includes a first light measuring element which measures light coming from an object to be photographed and an operational amplifier responsive to the element. A light measurement information producing circuit is included for producing a light measurement information signal for exposure computation. A change-over device is connected between the light measurement information producing circuit and the operational amplifier. The change-over device is arranged to be shiftable between a first position wherein the operational amplifier is connected to the light measurement information producing circuit and a second position wherein the operational amplifier is not so connected. An accessory device is attachable to the camera body. The accessory device includes a second light receiving element for measuring light from the object within a light measurement range different from that of the first light receiving element and another operational amplifier responsive thereto. A terminal is responsive to the signal from the latter operational amplifier. The terminal is disposed at the second position of the change-over device so that the signal from the latter operation is applied to the light measurement information producing circuit when the change-over device is in this position.

Automatic exposure control system for single reflex camera

An automatic exposure control system for cameras of flash photographic capabilities which is switched to either of the daylight or the mode depending upon whether or not a storage capacitor across which a flash tube is connected is sufficiently charged. The system comprises first and second computers for deriving daylight and flash exposure aperture values respectively, a diaphragm control circuit selectively receptive of the outputs of the computers through a first switch, first and second timing circuits for providing daylight and flash exposure times respectively, and a shutter control circuit selectively receptive of the outputs of the timing circuits through a second switch. The system is characterized in the use of a single mode selection actuator which is common to the first and second switches and which causes an automatic selection of the flash mode when the camera release occurs after the attainment of the voltage of the storage capacitor to the normal firing level. Thus, it is made possible to prevent occurrence of an event where the flash tube is actuated for firing with the simultaneous occurrence of selection of the flash exposure time, while the daylight exposure aperture remains effective, as the storage capacitor voltage reaches the normal firing level at a point in time during the daylight exposure operation.

Camera for daylight and flash photography

In the camera disclosed, an electromagnetic actuator is responsive to a timing pulse of short duration from an exposure control circuit for controlling the closing movement of a shutter. A permanent magnet may accidently be left latched and hold the rear curtain in cocked position after the timing pulse because of possible damage to an electromagnetic control circuit as a result of a battery short circuit. This may cause the film to fog during subsequent winding or rewinding. To prevent this, an indicator produces a visible indication either in the field of view of the camera finder or, in the case of remote shutter operation, outside the camera housing, that the rear curtain must be manually unlatched.

Camera with a device for protecting film against fogging

A motor drive unit adapted for use with a camera having a motorized shutter speed adjusting device. When a continuous series of frame exposures are to be made at a predetermined frame frequency, the set value of shutter time in the camera is made to be compared with the longest possible shutter time dependent upon that frame frequency by a comparator provided in the motor drive unit. When the actual shutter time value exceeds the longest possible one, the motorized shutter speed adjusting device is actuated, causing the shutter time value to change itself to the longest possible value.

Motor drive unit for a camera

In the system disclosed, a feedback circuit connects the output of the last of a plurality of cascaded amplifier stages to the input of the first stage. A photoelectric transducer is connected to one of the stages. The feedback connection compresses the output signal relative to the signal at the photoelectric transducer, logarithmically. Preferably all the stages are linear and the feedback circuit is linear so that no logarithmic members are required. Preferably each of the stages is composed of an amplifier and a connection corresponding to an emitter-follower connection. A suitable system then utilizes the compression characteristic in a shutter control. This system may use a second compression circuit comparable to the first. Additional photographic information may be applied to the input of any of the stages in either compression circuit.

Control circuit for a memory type electric shutter

A camera having an indication system to determine suitable diaphragm aperture value by measuring the light penetrating through a photographing lens and to indicate the same digitally, wherein when said diaphragm aperture value exceeds the limit value of exposure control of a camera, a warning indication is given by the indication means to indicate the fact that the diaphragm aperture value is outside of control limit, and the number of input/output lead wires to the indication means is reduced. Thus simplifying the set-up.

Indication system of a camera

A temperature compensating device for devices comprising semiconductors. The temperature compensating device comprises a temperature compensating circuit, such as a circuit including a diode, and a current control circuit which adjusts the quantity of the electric current flowing through the temperature compensating circuit. The temperature characteristic of the temperature compensating circuit is mutually compensatory with that of the output of the device comprising semiconductors. When the temperature characteristic of the output of said temperature compensating circuit differs from that of the output of such semiconductor device, the current control circuit causes a current which corresponds to the difference between the temperature coefficient of the compensating circuit and that of the semiconductor device to flow through the temperature compensating circuit, so that satisfactory temperature compensation can be accomplished.

Growing community of inventors

Yokohama, Japan

Yoshiyuki Takishima