Patents by Inventor Walter Bletz
Walter Bletz has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 6175695Abstract: A manually operable flashlight unit (10) having a foot part (11) fitting a finder shoe (6) on a camera (1), standard contacts (9′) for chassis ground and (8′) for flash release being arranged in the foot part (11), has the additional feature that a single further contact (7′) is provided in the foot part (11) for a bidirectional information exchange between a circuit arrangement (13) contained in the flashlight unit (10) and a circuit arrangement (12) arranged in the camera (1).Type: GrantFiled: April 29, 1999Date of Patent: January 16, 2001Assignee: Leica Camera AGInventors: Klaus Dieter Schaefer, Walter Bletz
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Patent number: 5907727Abstract: 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.Type: GrantFiled: August 20, 1997Date of Patent: May 25, 1999Assignee: Leica Camera AGInventors: Walter Bletz, Robert Denk, Gerhard Kranz, Rolf Magel
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Patent number: 4737668Abstract: 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.Type: GrantFiled: September 26, 1986Date of Patent: April 12, 1988Assignee: Ernst Leitz Wetzlar GmbHInventors: Walter Bletz, Rolf Magel, Helmut Bill
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Patent number: 4694155Abstract: 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.Type: GrantFiled: July 23, 1985Date of Patent: September 15, 1987Assignee: Ernst Leitz Wetzlar GmbHInventors: Walter Bletz, Rolf Magel
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Patent number: 4647175Abstract: 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.Type: GrantFiled: July 23, 1985Date of Patent: March 3, 1987Assignee: Ernst Leitz Wetzlar GmbHInventors: Walter Bletz, Rolf Magel
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Patent number: 4639134Abstract: 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.Type: GrantFiled: June 5, 1984Date of Patent: January 27, 1987Assignee: Ernst Leitz Wetzlar GmbHInventor: Walter Bletz
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Patent number: 4541700Abstract: 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.Type: GrantFiled: July 21, 1983Date of Patent: September 17, 1985Assignee: Ernst Leitz Wetzlar GmbHInventors: Walter Bletz, Herbert Machmerth, Walter Mandler
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Patent number: 4218613Abstract: 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.Type: GrantFiled: October 26, 1978Date of Patent: August 19, 1980Assignee: Ernst Leitz Wetzlar GmbHInventor: Walter Bletz
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Patent number: 4195909Abstract: 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.Type: GrantFiled: June 14, 1976Date of Patent: April 1, 1980Assignee: Ernst Leitz Wetzlar GmbHInventors: Werner Holle, Walter Bletz
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Patent number: 4117325Abstract: 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.Type: GrantFiled: October 26, 1977Date of Patent: September 26, 1978Assignee: Ernst Leitz Wetzlar GmbHInventors: Werner Holle, Walter Bletz
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Patent number: 4080611Abstract: Apparatus for storing a voltage analogous to an exposure parameter in photographic cameras with an electronic timer and with electric exposure measurement, having the characteristics that an analog-to-digital converter is provided as the storage unit, containing a digital-to-analog converter, the output voltage of which is fed to a comparator wherein this output voltage is compared with the voltage delivered by the exposure meter part. The signal obtained at the comparator output in the case of voltage identity stops the analog-to-digital converter and the voltage remaining at the output of the digital-to-analog converter controls the respective exposure parameter in the camera.Type: GrantFiled: July 1, 1976Date of Patent: March 21, 1978Assignee: Ernst Leitz GmbHInventors: Walter Bletz, Werner Holle
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Patent number: 4054887Abstract: Exposure control device for a photographic camera wherein, in a part of the exposure control device, electronic means are provided in order to form, from the luminous density of an object, the film sensitivity, and the preselected time, a voltage analogous to a diaphragm setting, and wherein a storage means is provided for storing this value, the improvement comprising the combination of the following features:A. when the camera release is actuated, the diaphragm begins to operate from an initial position corresponding to the maximum diaphragm opening, a diaphragm path meter coupled therewith operating simultaneously with this diaphragm and yielding a value corresponding to the change in aperture;B. means are provided which compare the value produced by the diaphragm path meter with the stored value and, in case of identical values, or compensation of the values, stop the operation of the diaphragm by a stop member;C.Type: GrantFiled: July 1, 1976Date of Patent: October 18, 1977Assignee: Ernest Leitz GmbHInventors: Werner Holle, Walter Bletz, Rolf Magel
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Patent number: 4047189Abstract: An electronic device for storing and indicating illumination parameters and for controlling the exposure time for photographic cameras having an exposure meter and a timer. The exposure meter includes an analog/digital converter with a digital storage part having a plurality of binary stages. These various stages correspond to different intensities of illumination of an object. The timer includes a combination of binary ratio reducers and logic gates and these are adapted to be selected by the analog/digital converter or by manual adjustment. A generator produces impulses which control the timer.Type: GrantFiled: March 15, 1976Date of Patent: September 6, 1977Assignee: Ernst Leitz GmbHInventors: Walter Bletz, Werner Holle
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Patent number: 4015275Abstract: Digital timers for the electronic control of a camera shutter having a pulse generator and a number of binary dividers each associated with a resistor, the total of these resistors performing a digital to analog conversion and being connected to a common point. The potential of the common point being representative for the number of the binary dividers being in "1" state. A comparator actuating a shutter solenoid when the potential of the common point reaches a predetermined value. All the resistors having the same conductance so that at those times corresponding to powers of 2 (reference timing series) values of potential are formed, which correspond to the logarithm of the time obtained.Type: GrantFiled: February 19, 1975Date of Patent: March 29, 1977Assignee: Ernst Leitz G.m.b.H.Inventor: Walter Bletz