Patents by Inventor Allan R. Kmetz

Allan R. Kmetz 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).

  • Patent number: 4529271
    Abstract: A matrix addressed, bistable liquid crystal optical display is disclosed. The display includes a liquid crystal twist cell which has at least two states which are stable in the presence of a single given holding voltage. A form of 3:1 matrix addressing is used in the display which enhances operational characteristics.
    Type: Grant
    Filed: March 12, 1982
    Date of Patent: July 16, 1985
    Assignee: AT&T Bell Laboratories
    Inventors: Dwight W. Berreman, William R. Heffner, Allan R. Kmetz
  • Patent number: 4506955
    Abstract: Liquid crystal elements are interconnected in an array of rows and columns, which are not independent of one another, and are addressed by pulsed signals which together reduce the number of leads N required to operate the display. The interconnection scheme includes connecting together the last column to the second row, the penultimate column to the third row, etc., and the first column to the last row. In one embodiment for randomly accessing the display, the addressing scheme divides a row-select signal and a column-select signal into two time-wise sequential subsets: a first subset which includes pulses of one polarity in the time slots corresponding to the elements in that row, and a second subset which includes pulses of either polarity depending on which elements in that column are to be turned on and which off. The coincidence of two pulses of opposite polarity applied to an element from the row-select and column-select signals in sufficent to turn on that element.
    Type: Grant
    Filed: May 6, 1983
    Date of Patent: March 26, 1985
    Assignee: AT&T Bell Laboratories
    Inventor: Allan R. Kmetz
  • Patent number: 4340277
    Abstract: A liquid crystal display including a cell which consists of two cell plates and a liquid crystal with positive dielectric anisotropy layered between the plates, where the molecules of the liquid crystal next to the plates exhibit preferred directions rotated by 90.degree.. The display includes only one polarizer that is placed on the front cell plate. A reflector formed of a layer of insulated metal particles is located inside the cell on the rear plate and exhibits a structure determining the preferred direction of the liquid crystal molecules. The electrode segments are holohedral and the operating voltage applied thereto lies between 1.3 and 2.5 times the Freedricksz threshold voltage.
    Type: Grant
    Filed: September 6, 1979
    Date of Patent: July 20, 1982
    Assignee: BBC Brown, Boveri, & Company, Limited
    Inventors: Meinolph Kaufmann, Allan R. Kmetz
  • Patent number: 4298249
    Abstract: An electro-optical display composed of two plates which enclose a display medium and a reflector located on the rear plate. The reflector consists of a thermoplastic material and consists of reflecting surface strips, inclined to the display plane, which reflect incident light beams into the eye of an observer. The surface strips which can be semi-transparent and/or diffusely reflecting are inclined with respect to the display plane at an angle .alpha. and extend rectilinearly in at most two different directions over the surface of the reflector. The angle of inclination .alpha. is either the same for all surface strips and has a value of between 20.degree. and 40.degree., or decreases progressively from an outermost surface strip to the subsequent surface strip. The reflector strips are produced by milling, embossing or injection molding of a suitable thermoplastic material.
    Type: Grant
    Filed: August 15, 1979
    Date of Patent: November 3, 1981
    Assignee: BBC Brown, Boveri & Company, Ltd.
    Inventors: Ernst Gloor, Meinolph Kaufmann, Allan R. Kmetz
  • Patent number: 4281902
    Abstract: An electro-optical display for the display of dark symbols against a bright background, wherein except for fine separation lines the front and rear cell plates are almost entirely covered with isolated electrode elements. The regions of overlap between these various front and rear electrode elements define the areas of the selectable display segments. The display employs an electro-optic media requiring no polarizers, for example, cholesteric liquid crystals to which has been added pleochroic dyes, or electrophoretic suspensions. The display device is addressed through the application of appropriate signals to the electrodes so that a vanishingly small potential difference lies across the liquid crystal layer in the region of the selected display segments which remain dark. In all the other regions of the display, however, there exists a potential difference which is larger than the transition voltage of the electro-optical medium, and these regions therefore appear as a bright background.
    Type: Grant
    Filed: July 17, 1978
    Date of Patent: August 4, 1981
    Assignee: BBC Brown, Boveri & Company Limited
    Inventors: Allan R. Kmetz, Klaus Muller
  • Patent number: 4271391
    Abstract: A digital voltmeter device is disclosed which displays both the numerical value of a measured voltage and a visual representation of an input waveform. The device includes an electro-optical display matrix utilizing display elements arranged in lines and columns. In order to make maximum use of the display matrix for representing input waveforms, the peak-to-peak voltage of the input waveform is measured and utilized as a reference for an analog to digital converter having output signals which form the address signals for the display matrix. The peak values of the input waveform thus appear at the top and bottom of the display matrix respectively.
    Type: Grant
    Filed: November 1, 1979
    Date of Patent: June 2, 1981
    Assignee: BBC Brown, Boveri & Co. Ltd.
    Inventor: Allan R. Kmetz
  • Patent number: 4258364
    Abstract: A display device including a plurality of adjoining display elements which comprise front and rear electrodes. The display elements are disposed geometrically in at least one row and are electrically grouped together to form at least one matrix. The display device further includes a drive circuit which drives the display elements in such a manner that along each row there is at most one transition from a first optical condition to a second optical condition different from the first.
    Type: Grant
    Filed: December 20, 1977
    Date of Patent: March 24, 1981
    Assignee: BBC Brown Boveri & Company Limited
    Inventors: Meinolph Kaufmann, Allan R. Kmetz
  • Patent number: 4253096
    Abstract: A method for addressing an electro-optical display device having a display comprising display elements which adjoin one another and are arranged in a row, each display element having two electrodes of two different types which are opposite one another and are separated from one another by a liquid crystal. The electrodes of the first type are connected to one another groupwise in an electrically conducting manner and the electrodes of the second types are connected to one another segment-wise in an electrically conducting manner.
    Type: Grant
    Filed: April 12, 1978
    Date of Patent: February 24, 1981
    Assignee: BBC Brown, Boveri & Company, Limited
    Inventor: Allan R. Kmetz
  • Patent number: 4241344
    Abstract: An electro-optical display for the display of dark symbols against a bright background, wherein except for fine separation lines the front and rear cell plates are almost entirely covered with isolated electrode elements. The regions of overlap between these various front and rear electrode elements define the areas of the selectable display segments. The display employs an electro-optic media requiring no polarizers, for example, cholesteric liquid crystals to which has been added pleochroic dyes, or electrophoretic suspensions. The display device is addressed through the application of appropriate signals to the electrodes so that a vanishingly small potential difference lies across the liquid crystal layer in the region of the selected display segments which remain dark. In all the other regions of the display, however, there exists a potential difference which is larger than the transition voltage of the electro-optical medium, and these regions therefore appear as a bright background.
    Type: Grant
    Filed: April 5, 1979
    Date of Patent: December 23, 1980
    Assignee: BBC Brown, Boveri & Company, Limited
    Inventors: Allan R. Kmetz, Klaus Muller, Terry J. Scheffer
  • Patent number: 4203104
    Abstract: A procedure for the display of measured quantities as a bargraph with the help of a row of addressable display elements, whereby the display elements are interconnected on one side into contiguous groups and on the other side according to like position within each group. Either the on-groups, in which all display elements are to be excited, or the mixed group, in which only a part of the display elements are to be excited, are addressed in a rapid alteration imperceptible to the eye of the beholder. The amplitude of the driving voltage across display elements in the mixed group is zero during the strobe interval for the on-groups.
    Type: Grant
    Filed: May 26, 1978
    Date of Patent: May 13, 1980
    Assignee: BBC Brown Boveri & Company Limited
    Inventor: Allan R. Kmetz
  • Patent number: 4142182
    Abstract: A procedure for the addressing of visual display devices comprising stylized alphanumeric characters which consist of similarly shaped front and rear display elements, whereby in the case of simultaneous selection of a front and the corresponding rear display elements, an optical activation of these elements results such that by coincident selection of the front and rear display elements of several pairs of elements having a specific geometrical configuration a corresponding alphanumeric character becomes visible, whereby further the number of address leads and drivers is reduced by interconnecting the display elements as a matrix and by time-sharing the address leads through multiplexed operation in such a way that the address leads in one matrix dimension are used to select the front elements of the display and the address lines in the second matrix dimension are used to select the rear elements of the display and the address leads in one of these matrix dimensions extend over more than one character.
    Type: Grant
    Filed: February 16, 1977
    Date of Patent: February 27, 1979
    Assignee: BBC Brown, Boveri & Company, Limited
    Inventor: Allan R. Kmetz
  • Patent number: 4088992
    Abstract: An electro-optical display device and a method of manufacturing it are disclosed. The display device includes a liquid crystal cell arranged between two polarizers. A light source is positioned adjacent one polarizer on the side thereof remote from the liquid crystal cell, and an electronic control device is coupled to the liquid crystal cell. A diaphragm is arranged on one side of the liquid crystal cell in the form of an aperture for limiting the display field of the liquid crystal. The device limits viewing parallax and improves contrast for both day and night viewing.
    Type: Grant
    Filed: April 30, 1976
    Date of Patent: May 9, 1978
    Assignee: BBC Brown, Boveri & Company, Limited
    Inventors: Allan R. Kmetz, Peter J. Wild
  • Patent number: 3946421
    Abstract: Adjacent CCD phase electrodes in different levels separated by an insulating layer are connected to multi level phase buses on one side of the phase electrode by secondary bus means extending from one electrode in one level to an electrode of the same phase spaced therefrom in a different level by way of a vias through the insulation layer at a location intermediate the buses and the phase electrodes.
    Type: Grant
    Filed: June 28, 1974
    Date of Patent: March 23, 1976
    Assignee: Texas Instruments Incorporated
    Inventors: Glenn A. Hartsell, Allan R. Kmetz
  • Patent number: 3931510
    Abstract: A dispersion compensated CTD controlled data display where a serial-parallel-serial CTD is loaded at a low data rate with clock means to shift data from the CTD at a high data rate. A transversal filter is connected in series with the CTD to provide a dispersion corrected output of the data. The output is applied to the input of the CTD at the high data rate and to a display unit with reloading of the CTD to change the display.
    Type: Grant
    Filed: July 12, 1974
    Date of Patent: January 6, 1976
    Assignee: Texas Instruments Incorporated
    Inventor: Allan R. Kmetz