LIQUID CRYSTAL BAR GRAPH DISPLAY

• US 3,835,465 A
• Filed: 02/28/1973
• Issued: 09/10/1974
• Est. Priority Date: 02/28/1973
• Status: Expired due to Term

• Current Assignee: John V. Hobbs, Lawrence E Tannas Jr
• Original Assignee: John V. Hobbs, Lawrence E Tannas Jr
• Inventors: Tannas, Lawrence E. Jr., Hobbs, John V.
• Primary Examiner(s): Trafton, David L.
• Application Number:
  US05/337,259
• Time in Patent Office: 559 Days
• Field of Search: 340/324R,378R,336 315/169R 350/16LC
• US Class Current: 345/40
• CPC Class Codes: G01R 13/407 using a plurality of passive display elements, e.g. liquid crystal or Kerr-effect display elements G01R13/408 takes precedence
• CPC Class Codes: G02F 1/133 Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements arrangements or circuits for control of liquid crystal elements in a matrix, not structurally associated with these elements G09G3/36

Abstract

An analog display in the form of a plurality of bar graphs is provided by an arrangement of horizontally extending graphic electrode strips cooperating with vertically disposed and mutually discrete common electrode strips and a film of liquid crystal material confined between the electrodes. Selected groups of the horizontal graphic electrode strips are energized in accordance with the magnitude of a bidirectionally varying signal, and a selected one or more of the common electrodes are concurrently energized to selectively display the several bar graphs in a time shared arrangement.

Claims

1. A display comprising a panel including first and second plates, a layer of liquid crystal material coNfined between said plates, common electrode means on said first plate, a plurality of discrete electrode strips arranged on said second plate in a pattern to collectively delineate a continuous bar extending normal to the extent of individual ones of said strips, means for electrically energizing said common electrode means, means for electrically energizing one or more of said electrode strips whereby the energized electrode strips will visually express the value of an analog signal by activating a portion of said confined liquid crystal layer along a length of said bar pattern, a first transducer for developing a first variable analog signal, a second transducer for developing a second variable analog signal, said means for electrically energizing said electrode strips including a multiplexer responsive to signals fed from said first and second transducers for energizing groups containing a number of strips substantially proportional to the signals fed from said transducers to said multiplexer, said common electrode means comprising first and second discrete common electrodes each extending the full length of said bar pattern and each having a width less than the full extent of said individual electrode strips, and means for alternately energizing said common electrodes in synchronism with said multiplexer.

2. The display of claim 1 wherein said common electrode means includes first and second discrete common electrodes each extending in a direction normal to the extent of individual ones of said electrode strips, each of said discrete common electrodes having the length of said bar pattern and a width of a fraction of the length of said electrode strips, said means for electrically energizing said electrode strips comprising means for energizing different electrode strips in accordance with different analog signals, said means for energizing said common electrode means comprising means for energizing said first and second common electrodes in synchronism with the energization of said electrode strips in accordance with said analog signals.

3. The display of claim 1 wherein, said display includes a scale positioned in proximity to said bar pattern and having indicia extending along said bar, said scale includes a plurality of strips of different colors respectively indicating different conditions of the values displayed.

4. The display of claim 1 wherein each of a group of said strips extends continuously from an intermediate portion of said second plate to an edge of said second plate for connection with said strip energizing means, and including a second plurality of discrete electrode strips arranged in a pattern to collectively delineate a second continuous bar extending normal to the extent of individual ones of said second plurality of electrodes strips, said second continuous bar being positioned adjacent to said first continuous bar, each of the strips of said second plurality of electrode means extending from said intermediate portion of said second plate to a second edge of said second plate, means connected to said second plurality of electrode means at said second edge for energizing one or more of said second plurality of electrode strips, second common electrode means on said first plate oppositely disposed with respect to said second bar pattern, and means for electrically energizing said second common electrode means.

5. The display of claim 4 wherein each strip of said first graphic electrode means extends continuously for the width of both said first and second common electrodes.

6. The display of claim 4, wherein said second graphic electrode means is electrically isolated from said first-mentioned graphic electrode means.

7. A parameter display comprising first and second glass plates and a liquid crystal material confined between said plates, first and second mutually discrete common electrodes extending substantially continuousLy in a bar pattern on said first plate, graphic electrode means on said second plate, said graphic electrode means comprising a plurality of mutually discrete, adjacent and parallel electrode strips each extending continuously across the width of both of said common electrodes to an edge of said second plate, said graphic electrode means collectively delineating first and second continuous bars, each congruent with a respective one of said common electrodes, means for receiving first and second bidirectionally variable analog signals, means responsive to said analog signals for electrically energizing said electrode strips in alternate groups of adjacent strips, said groups including a number of strips that varies in either sense in accordance with alternate ones of said analog signals, means for alternately energizing said first and second common electrodes, means for synchronizing the alternate energization of said common electrodes with the alternate energization of said groups of graphic electrode strips in accordance with said first and second bidirectionally variable analog signals, third and fourth common electrodes on said first plate each extending for the length of said first and second common electrodes and being insulated relative to each other and to said first and second common electrodes, second graphic electrode means electrically isolated from said first-mentioned graphic electrode means and comprising a plurality of mutually discrete, adjacent and mutually parallel electrode strips arranged in a pattern congruent with both of said third and fourth common electrodes to collectively delineate third and fourth continuous bars congruent to said third and fourth common electrodes, respectively, means for receiving third and fourth analog signals, means for electrically energizing the electrode strips of said second graphic electrode means in alternate groups of adjacent strips, said groups including a number of strips that varies in either sense in accordance with said third and fourth analog signals alternately, means for electrically energizing said third and fourth common electrodes alternately in synchronism with the energization of said alternate groups of strips of said second graphic electrode means in accordance with said third and fourth analog signals, respectively, electrode strips of said first graphic electrode means extending to a first edge of said second plate for external electrical connection, and electrode strips of said second graphic electrode means extending to a second edge of said second plate for external electrical connection.