SCANNER DEVICES UTILIZING FIELD EFFECT LIGHT SCATTERING DIELECTRICS

• US 3,820,875 A
• Filed: 04/14/1972
• Issued: 06/28/1974
• Est. Priority Date: 04/14/1972
• Status: Expired due to Term

• Current Assignee: Control Interface Company Limited
• Original Assignee: Bohmer W
• Inventors: BOHMER W
• Application Number:
  US05/243,996
• Time in Patent Office: 805 Days
• US Class Current: 349/74
• CPC Class Codes: G02F 1/05 with ferro-electric properties G02F1/035, G02F1/055 take 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
• CPC Class Codes: G02F 1/133514 Colour filters
• CPC Class Codes: G02F 1/1347 Arrangement of liquid crystal layers or cells in which the final condition of one light beam is achieved by the addition of the effects of two or more layers or cells

Abstract

A region of a field effect light scattering dielectric is selectively actuated in a device including a pair of spaced plates having said field effect light scattering dielectric therebetween and having a resistor defining a resistive electrical path of predetermined length and configuration mounted on the inner surface of one of said plates and a substantially nonresistive conductor mounted on the inner surface of the other of said plates in facing relation to said resistor. At least one of said plates and the resistor or conductor mounted thereon are transparent. A first voltage is applied between the ends of the electrical path of said resistor and a second variable voltage is applied to said conductor. Selective adjustment of said second voltage displaces the point on said resistor at which the voltage equals said second voltage to render the region of said dielectric adjacent said point visually distinguishable from other regions thereof.

Claims

1. A device for rendering selected regions of field effect light scattering dielectrics visually distinguishable from other regions thereof by selective alteration of the light scattering capabilities thereof comprising first and second base members aligned in spaced relation along an axis;

a resistor mounted on said first base member facing said second base member and defining a resistive electrical path of predetermined length and a zig-zag configuration, said electrical path including an array of substantially parallel, closely spaced segments;

a substantially non-resistive conductor mounted on said second base member facing and overlapping said resistor in the direction of said axis;

a field effect light scattering dielectric positioned between said first and second base members at least in the region of said resistor and conductor, at least one of said first and second base members and the one of said resistor and conductor mounted thereon being substantially transparent; and

means for applying a first voltage across at least the portion of the electrical path of said resistor defining said array and for applying a second variable voltage to said conductor, said means permitting selective setting of said second voltage to displace along the portion of said electrical path of said resistor defining said array the point on said electrical path at which the voltage equals said second voltage to render the region of said dielectric adjacent said zero potential difference point visually distinguishable from other regions thereof.

2. A device as recited in claim 1, wherein said dielectric is a liquid crystal material of a type rendered substantially opaque when subjected to a D.C. electric field and rendered substantially transparent when subjected to an A.C. field, said first and second voltages being D.C. voltages for producing D.C. electric fields, and including means for applying an A.C. electrical field to said dielectric simultaneous with the application of said D.C. electrical fields for rendering the region of said dielectric adjacent said zero potential difference point substantially transparent.

3. A device as recited in claim 2, wherein said liquid crystal material is a storage mode nematic-cholesteric liquid crystal material.

4. A device as recited in claim 1, wherein said dielectric is a liquid crystal material of a type rendered substantially opaque when subjected to a D.C. electric field and rendered substantially transparent when subjected to an A.C. electric field, said first and second voltages being A.C. voltages of substantially the same frequency and substantially 180* out of phase for producing A.C. electric fields, and including means for applying a D.C. electric field to said dielectric simultaneous with the application of said A.C. electric fields for rendering the region of said dielectric adjacent said zero potential difference point substantially opaque.

5. A device as recited in claim 4, wherein said liquid crystal material is a storage mode nematic-cholesteric liquid crystal material.

6. A device as recited in claim 1, wherein said portion of said electrical path of said resistor has a substantially linear resistance.

7. A device as recited in claim 1, wherein said dielectric is a nematic liquid crystal material.

8. A device as recited in claim 1, wherein said dielectric is a ferroelectric ceramic crystal material.

9. A device as recited in claim 1, wherein both said conductor and resistor and both of said base members are substantially transparent.

10. A device as recited in claim 1, wherein said voltage means is adapted to permit the continuous adjustment of said second voltage along a range of values corresponding to the voltage drop across said length of said resistor.

11. A device as recited in claim 1, wherein said voltage means is adapted to permit selective control of the rate of varying of said second voltage, the degree to which the region of said dielectric adjacent each zero potential difference point along said electrical path is visually distinguishable from other regions thereof depending on the period of time during which said zero potential difference point remains substantially adjacent said region.

12. A device as recited in claim 11, including mask means aligned with said portion of said electrical path of said resistor defining said array, said mask means including alternate transparent and opaque regions, said opaque regions masking zero potential points in registration therewith to render them visually indistinguishable.

13. A device as recited in claim 12, wherein said transparent regions of said mask means are selectively colored for the selective coloring of the visually distinguishable regions of said dielectric.

14. A device as recited in claim 11, including mask means aligned with said portion of said electrical path of said resistor defining said array, said mask means including alternating regions of at least three colors for selectively coloring the visually distinguishable regions of said dielectric.

15. A device for rendering selected regions of field effect light scattering dielectrics visually distinguishable by selective alteration of the light scattering capabilities thereof comprising first and second base members aligned in spaced relation along an axis;

a resistor mounted on said first base member facing said second base member along said axis and defining a resistive electrical path of predetermined length and configuration;

a plurality of parallel substantially non-resistive conductor strips mounted on said first member and extending, in a direction substantially transverse to said axis, from and electrically connected to a plurality of points spaced along the length of said electrical path of said resistor;

a substantially non-resistive conductor mounted on said second base member so as to face and overlap at least said conductor strips along said axis;

a field effect light scattering dielectric positioned between said first and second base members at least in the region of said conductor strips and conductor, at least one of said first and second base members and the resistor, conductor strips or conductor mounted thereon being substantially transparent; and

means for applying a first voltage across said electrical path of said resistor and for applying a second variable voltage to said conductor, said voltage means permitting selective setting of said second voltage to displace, along said electrical path, the point on said electrical path at which the voltage equals said second voltage, each of said conductor strips substantially assuming the voltage of the associated point on said electrical path so as to render the region of said dielectric adjacent the conductor strip associated with said zero potential difference point on said electrical path visually distinguishable from other regions thereof.

16. A device as recited in claim 15, including first and second of said devices aligned on said axis and overlapping in the direction of said axis, said first device being oriented relative to said second device about said axis so that a projection of the conductor strips of said first device in the direction of said axis inTersects the conductor strips of said second device, at least all of the base members, resistors, conductive strips and conductors of said first and second devices except one outer base member and the resistor, conductive strips or conductor mounted thereon as viewed along said axis being transparent whereby a selected aligned region of the respective dielectrics of said first and second devices representing the intersection of the second zero potential difference strip regions of said first and second devices is rendered visually distinguishable from other regions thereof.

17. A device as recited in claim 16, including control circuit means for coordinately controling the voltage means of said first and second devices for coordinately setting the respective second voltages of said first and second devices to select the aligned region to be rendered visually distinguishable.

18. A device as recited in claim 16, wherein said first and second devices are aligned so that the projection of the conductive strips of said first device along said axis intersects the conductor strips of said second device at a substantially right angle.

19. A device as recited in claim 18, wherein the respective resistors of said first and second devices are formed so that each of said electrical paths extend along a straight line, the projection of the electrical path of the resistor of said first device along said axis on the electrical path of the resistor of said second device intersecting said electrical path of said second device at substantially a right angle.

20. A device as recited in claim 16, wherein one of the first and second base members of said first device is formed integral with one of said first and second base members of said second device.

21. A device for rendering selected regions of field effect light scattering dielectrics visually distinguishable from other regions thereof by selective alteration of the light scattering capabilities thereof comprising first, second, third and fourth base members aligned along an axis with said first and second base members in spaced relation and said third and fourth base members in spaced relation along said axis;

a resistor mounted on said first base member facing said second base member along said axis and defining a resistive electrical path of predetermined length and configuration;

a substantially non-resistive conductor mounted on said second base member so as to face and overlap said resistor in the direction of said axis;

a first field effect light scattering dielectric positioned between said first and second base members at least in the region of said resistor and conductor;

means for applying a first voltage across said electrical path of said resistor and for applying a second variable voltage to said conductor, said means permitting selective setting of said second voltage to displace along said electrical path the point on said electrical path at which the voltage equals said second voltage to render the region of said dielectric adjacent said zero potential difference point visually distinguishable from other regions thereof;

a second substantially non-resistive conductor mounted on said third base member facing said fourth base member along said axis and overlapping said resistor in the direction of said axis;

a third substantially non-resistive conductor mounted on said fourth base member so as to face and overlap said third conductor in the direction of said axis;

a second field effect light scattering dielectric positioned intermediate said third and fourth base members in the region of said second and third conductors, at least all but one outer, as viewed along said axis, of said first, second, third and fourth base members and the resistor or conductor mounted thereon being substantially transparent; and

second means for applying a selectively variable third voltage between said second and third conductors for the application of an electric field of selected strength to said second dielectric for tHe selective control of the light transmission capability thereof, whereby the selective setting of said third voltage modulates the degree to which the region of said first-mentioned dielectric adjacent the zero potential difference point on the electrical path of said resistor is rendered visually distinguishable.

22. A device as recited in claim 21, wherein at least one of said first and second base members and one of said third and fourth base members are formed integral with each other.

23. A device as recited in claim 21, including control circuit means for the coordinate regulation of said first and second voltage means for the selective control of the third voltage applied by said second means at each zero potential difference point along the electrical path of said resistor.

24. A device for rendering selected regions of field effect light scattering dielectrics visually distinguishable from other regions thereof by selective alteration of the light scattering capabilities thereof comprising first, second, third and fourth base members aligned along an axis with said first and second base members in spaced relation and said third and fourth base members in spaced relation along said axis;

a resistor mounted on said first base member facing said second base member along said axis and defining a resistive electrical path of predetermined length and configuration;

a substantially non-resistive conductor mounted on said second base member so as to face and overlap said resistor in the direction of said axis;

a first field effect light scattering dielectric positioned between said first and second base members at least in the region of said resistor and conductor;

means for applying a first voltage across said electrical path of said resistor and for applying a second variable voltage to said conductor, said means permitting selective setting of said second voltage to displace along said electrical path the point on said electrical path at which the voltage equals said second voltage to render the region of said dielectric adjacent said zero potential difference point visually distinguishable from other regions thereof;

a second resistor mounted on said third base member and facing said fourth base member along said axis and defining a resistive electrical path of predetermined length and configuration corresponding to and overlapping in the direction of said axis the electrical path of said first-mentioned resistor;

a second conductor mounted on said fourth base member so as to face and overlap said second resistor in the direction of said axis;

a second field effect light scattering dielectric positioned between said third and fourth base members in the region of said second resistor and said second conductor, all but the outer, as viewed in the direction of said axis, of said first, second, third and fourth base members and the resistor or conductor mounted thereon being substantially transparent; and

means for applying a third voltage across the electrical path of said second resistor and for applying a fourth variable voltage to said second conductor, said means permitting selective setting of said fourth voltage to displace along the electrical path of said second resistor the point on said electrical path at which the voltage equals said fourth voltage, the respective overlapping regions, as viewed in the direction of said axis, of said first and second dielectrics being rendered visually distinguishable to the extent that the respective zero potential difference points on the electrical paths of said firstmentioned and second resistors overlap.

25. A device as recited in claim 24, wherein one of said first and second base members and one of said second and third base members are integrally formed.

26. A device as recited in claim 24, including control circuit means operatively coupled to said first and second means for coordinately controlling said second and fourth voltages for selectively controlling the degree of overlapping in the direction of said axis of the respective zero potential difference points on the electrical paths of said first-mentioned and second resistors.

27. A device for rendering selected regions of field effect light scattering dielectrics visually distinguishable from other regions thereof by selective alteration of the light scattering capabilities thereof comprising first and second base members aligned in spaced relation along an axis;

a resistor mounted on said first base member facing said second base member along said axis and defining a resistive electrical path of predetermined length and configuration;

a substantially non-resistive conductor mounted on said second base member so as to face and overlap said resistor in the direction of said axis;

a field effect light scattering dielectric positioned between said first and second base members at least in the region of said resistor and conductor, at least one of said first and second base members and the resistor or conductor mounted thereon being substantially transparent;

means for applying a first voltage across the electrical path of said resistor and for applying a second variable voltage to said conductor, said means permitting selective setting of said second voltage to displace along said electrical path the point on said electrical path at which the voltage equals said second voltage to render the region of said dielectric adjacent said zero potential difference point visually distinguishable from other regions thereof, said field effect light scattering dielectric being a liquid crystal material of a type rendered substantially opaque when subjected to a D.C. electric field and rendered substantially transparent when subjected to an A.C. field, said first and second voltages being D.C. voltages for producing D.C. electric fields, and means for applying an A.C. electric field to said dielectric for rendering the region of said dielectric adjacent said zero potential point substantially transparent.

28. A device as recited in claim 27, wherein said means for applying said A.C. electric field includes an A.C. source adapted to produce an A.C. signal of an amplitude and frequency selected to render said dielectric substantially transparent;

and means for connecting said A.C. source between said resistor and said conductor, said connecting means including means for providing D.C. isolation for said A.C. source.

29. A device as recited in claim 27, wherein said means for applying said A.C. electric field includes a layer of electrically insulating material mounted on said first base member intermediate said first base member and said resistor;

a second substantially non-resistive conductor mounted on said first base member intermediate said first base member and said layer of insulating material and overlapping, in the direction of said axis, said resistor;

an A.C. source adapted to produce an A.C. signal of an amplitude and frequency selected to render said dielectric substantially transparent; and

means for connecting said A.C. source between said first and second conductors for applying said A.C. field to said dielectric.

30. A device as recited in claim 28, wherein said dielectric is a storage mode nematic-cholesteric liquid crystal material.

31. A device as recited in claim 29, wherein said dielectric is a storage mode nematic-cholesteric liquid crystal material.

32. A device as recited in claim 29, wherein said A.C. source is adjustable to control the degree of visibility of said zero potential difference point.

33. A device for rendering selected regions of field effect light scattering dielectrics visually distinguishable from other regions thereof by selective alteration of the light scattering capabilities thereof comprising first and second base members aligned in spaced relation along an axis;

a resistor mounted on said first base member facing said second base member along said axis and defining a resistive electrical path oF predetermined length and configuration;

a substantially non-resistive conductor mounted on said second base member so as to face and overlap said resistor in the direction of said axis;

a field effect light scattering dielectric positioned between said first and second base members at least in the region of said resistor and conductor, at least one of said first and second base members and the resistor or conductor mounted thereon being substantially transparent;

means for applying a first voltage across the electrical path of said resistor and for applying a second variable voltage to said conductor, said means permitting selective setting of said second voltage to displace along said electrical path the point on said electrical path at which the voltage equals said second voltage to render the region of said dielectric adjacent said zero potential difference point visually distinguishable from other regions thereof, said field effect light scattering dielectric being a liquid crystal material of a type rendered substantially opaque when subjected to a D.C. electric field and rendered substantially transparent when subjected to an A.C. field, said first and second voltages being A.C. voltages of substantially the same frequency and substantially 180* out of phase with each other for producing A.C. electric fields; and

means for applying a D.C. field to said dielectric simultaneous with the application of said A.C. fields for rendering the region of said dielectric adjacent said zero potential difference point on said electrical path of said resistor substantially opaque.

34. A device as recited in claim 33, wherein said means for applying said D.C. electric field includes a D.C. source;

and means for connecting said D.C. source between said resistor and said conductor, said connecting means including means for D.C. isolating said D.C. source from said A.C. voltages.

35. A device as recited in claim 33, wherein said means for applying a D.C. field includes a layer of insulating material mounted on said first base member intermediate said first base member and said resistor;

a second substantially non-resistive conductor mounted on said first base member intermediate said layer of insulating material and said first base member and overlapping in the direction of said axis said resistor;

a D.C. source; and

means connecting D.C. source between said first-mentioned and second conductors for applying a D.C. electric field to said dielectric simultaneous with the application of said A.C. electric fields for rendering the region of said dielectric adjacent said zero potential difference point substantially opaque.

36. A device as recited in claim 34, wherein said dielectric is a storage mode nematic-cholesteric liquid crystal material.

37. A device as recited in claim 35, wherein said dielectric is a storage mode nematic-cholesteric liquid crystal material.

38. A device as recited in claim 35, wherein said D.C. source is variable for the selective control of the degree of visibility of said zero potential difference point.

39. A device for rendering selective regions of field effect light scattering dielectrics visually distinguishable from other regions thereof by selective alteration of the light scattering capabilities thereof comprising first and second base members positioned in spaced relation along an axis;

a resistor mounted on said first base member facing said second base member along said axis and defining a resistive electrical path of predetermined length and configuration;

a substantially non-resistive conductor mounted on said second base member so as to face and overlap said resistor in the direction of said axis;

a field effect light scattering dielectric positioned between said first and second base members at least in the region of said resistor and conductor, at least one of said first and second base members and the resistor or conductor mounted thereon being substantially transparent;

anD means applying a first voltage across said electrical path of said resistor and for applying a second variable voltage to said conductor, said means permitting selective variation of said second voltage at selected rates of voltage variation to displace along said electrical path the point on said electrical path at which the voltage equals said second voltage to selectively render each region of said dielectric adjacent each zero potential difference point along said electrical path visually distinguishable from other regions thereof when the rate of voltage variation is less than a predetermined value and not visually distinguishable from other regions thereof when the rate of voltage variation exceeds said predetermined value.