Ernst Leitz Wetzlar Gmbh

Leica Camera Ag

Walter Bletz

Rolf Magel

Werner Holle

Gerhard Kranz

Walter Mandler

Robert Denk

Herbert Machmerth

Klaus Dieter Schaefer

Helmut Bill

A manually operable flashlight unit (,) having a foot part (,) fitting a finder shoe (,) on a camera (,), standard contacts (,) for chassis ground and (,) for flash release being arranged in the foot part (,), has the additional feature that a single further contact (,) is provided in the foot part (,) for a bidirectional information exchange between a circuit arrangement (,) contained in the flashlight unit (,) and a circuit arrangement (,) arranged in the camera (,).

Manually operable flashlight unit

A device for exposure metering in photographic cameras including a reflector located in the imaging beam path. The surface of the reflector is provided with a reflecting structure whose size corresponds at least approximately to that of the image recording format. At least one photoelectric receiver records the light intensity of a portion of the image reflected from the reflecting structure. The reflector is pivotally mounted in the camera housing such that during exposure metering the reflector surface is in the vicinity of the film plane of the camera. A limited portion of the reflector is transparent and a photoelectric receiver is set into the backside of the reflector behind the transparent portion.

Device for exposure metering

A circuit arrangement for reducing the settling time of amplifiers to which photoelectronic components are connected. A control circuit is provided which, operating in conjunction with components of this circuit arrangement, prevents the parasitic capacitance of the photoelectronic component from being charged up when the circuit arrangement is connected to the operating voltage.

Circuit arrangement for reducing the settling time of logarithmic

A circuit containing a photodiode for determining when there is sufficient illumination for an optical device to operate having provision for compensating signal variations due to temperature-dependent operation of the photodiode by supplying logarithmic means with an input from a potentiometer connected to a temperature-dependent distributor circuit.

Circuit arrangement to ascertain and indicate that a luminous density

In a switching circuit for an electronic exposure meter in optical devices with a photoelectric converter at the input of an amplifier which logarithmizes the output current from said converter, with a temperature compensation circuit and a photoelectric current limit value circuit and with an indicator, a voltage supply source having a main switch, means are provided on the device for coupling to the main switch. These means effect automatic connection or disconnection of the switching circuit to or from the supply source.

Circuit arrangement for an electronic exposure meter

To amplify an input current present at the input of a circuit arrangement with a feedback-coupled operational amplifier, two virtually equal potentials are built up in two different current paths with a common summing point. By means of the potentials, a current flow is produced for each current path. The current flow in one current path is determined by the input current, and the current in the second current path determined by a suitable choice of the impedances on the first and second current paths. The current in the second current path is greater by a multiple than the current in the first current path.

Process and circuit arrangement for amplifying an input current

Active lens components are provided for transmitting to a corresponding photographic camera information from a photographic field lens which is transformed into electrical signals. These components transform the information into electrical signals, the properties of which are convertible. The signals are transmitted to an evaluating circuit in the camera either serially via a contacting device or according to a predetermined chronological sequence. The evaluation circuit is provided with means by which the original information is gained back from the signals. The signals resulting from the recovery are fed to display means and/or to control arrangements for additional camera functions. The contact for the transfer of information is also employed as a power supply contact.

Method and devices for transferring electrical signal information

Disclosed is an amplifier for electrical signals obtained by means of a photoelectric transducer as a function of the intensity of illumination incident upon said transducer, comprising an operational amplifier adapted to be connected in series after the photoelectric transducer and having a feedback branch, wherein the feedback branch of the operational amplifier includes an electrical element having a nonlinear characteristic connected in parallel with a resistance.

Amplifier for electric signals

An improved scanning grating useful as an image scanner and spatial frequency filter, for a focusing detector to ascertain the focus of an optical system on deflecting the light incident from the optical system into two different directions for forming two images of the exit pupil or of parts thereof of said optical system. A slit grating is superimposed over the groove grating so that the ledges cover the peaks and the troughs thereof. It is thereby attained that the signals obtained from the peak and trough areas, which normally are more or less undefined, are exempt from evaluation. The ledges have a width ranging from 10 to 100 percent of that of the slit width.

Scanning grating for a focus detector

Apparatus for indicating and displaying the focus of an optical objective and particularly a photographic camera. An image of the object is projected by means of the objective onto a scanning disk or plate where the light rays are divided into two separate light beams originating from two different areas of the exit pupil of the objective. Two photoelectric detectors are provided behind said scanning disk with one of said light beams impinging on one detector. Each detector delivers an electrical signal, the phase difference between these signals being a measure of the degree of focus of the objective. For indicating said degree of focus two LED's (Light Emitting Diodes) are provided which are so coupled that for focus (phase difference = null) they are equally luminous and that for lack of focus they indicate the direction of the image offset from the focusing plane and approximately also the magnitude of this offset on account of their special coupling and their change in luminosity which is independent of object brightness.

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Braunfels, Germany

Walter Bletz