Light source

• US 20060022604A1
• Filed: 03/17/2005
• Published: 02/02/2006
• Est. Priority Date: 07/27/2004
• Status: Active Grant

• Current Assignee: NGK Insulators Limited
• Original Assignee: NGK Insulators Limited
• Inventors: Nanataki, Tsutomu, Ohwada, Iwao, Akao, Takayoshi, Takeuchi, Yukihisa
• Granted Patent: US 7,230,371 B2
• Time in Patent Office: Days
• US Class Current: 315/169.300
• CPC Class Codes: B82Y 10/00 Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
• CPC Class Codes: H01J 1/312 having an electric field perpendicular to the surface, e.g. tunnel-effect cathodes of metal-insulator-metal [MIM] type H01J1/304- H01J1/308 take precedence
• CPC Class Codes: H01J 2201/306 Ferroelectric cathodes
• CPC Class Codes: H01J 63/08 Lamps with gas plasma excited by the ray or stream

Abstract

A light source has a rear glass substrate and a front glass substrate having a plate surface disposed in facing relation to a principal surface of the rear glass substrate. The plate surface of the front glass substrate is coated with a phosphor. A two-dimensional array of electron emitters is disposed on the principal surface of the rear glass substrate. A space defined between the rear glass substrate and the front glass substrate is filled with a gas. The gas may be an Hg (mercury) gas or an Xe (xenon) gas.

Claims

1. A light source of a discharge lamp type, wherein

electrons ignite or assist in an electric discharge;

a source of said electrons comprises an electron emitter; and

said electron emitter comprises an emitter of a dielectric material and a first electrode and a second electrode which are disposed on said emitter;

wherein when a drive voltage is applied between said first electrode and said second electrode, at least a portion of said emitter has its polarization inverted or changed to emit electrons.

2. A light source according to claim 1, wherein when said drive voltage is applied between said first electrode and said second electrode, at least said portion of said emitter has its polarization inverted to position positive poles of dipoles around said first electrode to draw primary electrons from said first electrode, and said primary electrons drawn from said first electrode impinge upon said emitter to cause said emitter to emit secondary electrons.

3. A light source according to claim 2, including:

a triple point made up of said first electrode, said emitter, and a vacuum atmosphere;

wherein said primary electrons are drawn from a portion of said first electrode near said triple point, and said primary electrons drawn from said first electrode impinge upon said emitter to cause said emitter to emit secondary electrons.

4. A light source according to claim 1, including:

means for applying AC pulses between said first electrode and said second electrode to cause at least said portion of said emitter to have its polarization inverted or changed;

wherein electrons are intermittently emitted from said emitter.

5. A light source according to claim 4, wherein before light emitted by a first emission of electrons is extinguished, next electrons are emitted to emit light continuously.

6. A light source according to claim 1, including:

a plurality of said electron emitters, said electron emitters being arranged in a two-dimensional array.

7. A light source according to claim 1, including:

means for modulating said drive voltage based on a control signal to control an amount of electrons emitted from said electron emitter for controlling emitted light.

8. A light source for emitting light by exciting a phosphor with an ultraviolet radiation generated from a gas sealed in a space in the light source, wherein

electrons assist in generating the ultraviolet radiation from the gas;

a source of said electrons comprises an electron emitter; and

said electron emitter comprises an emitter of a dielectric material and a first electrode and a second electrode which are disposed on said emitter;

wherein when a drive voltage is applied between said first electrode and said second electrode, at least a portion of said emitter has its polarization inverted or changed to emit electrons.

9. A light source according to claim 8, wherein when said drive voltage is applied between said first electrode and said second electrode, at least said portion of said emitter has its polarization inverted to position positive poles of dipoles around said first electrode to draw primary electrons from said first electrode, and said primary electrons drawn from said first electrode impinge upon said emitter to cause said emitter to emit secondary electrons.

10. A light source according to claim 9, including:

a triple point made up of said first electrode, said emitter, and a vacuum atmosphere;

wherein said primary electrons are drawn from a portion of said first electrode near said triple point, and said primary electrons drawn from said first electrode impinge upon said emitter to cause said emitter to emit secondary electrons.

11. A light source according to claim 8, including:

means for applying AC pulses between said first electrode and said second electrode to cause at least said portion of said emitter to have its polarization inverted or changed;

wherein electrons are intermittently emitted from said emitter.

12. A light source according to claim 11, wherein before light emitted by a first emission of electrons is extinguished, next electrons are emitted to emit light continuously.

13. A light source according to claim 8, including:

a plurality of said electron emitters, said electron emitters being arranged in a two-dimensional array.

14. A light source according to claim 8, including:

means for modulating said drive voltage based on a control signal to control an amount of electrons emitted from said electron emitter for controlling emitted light.

15. A light source for emitting light from a phosphor by having electrons and/or ions impinge upon said phosphor, said electrons and/or ions being produced when electrons impinge upon molecules of a gas sealed in a space in said light source and ionize said molecules of the gas, wherein

a source of said electrons comprises an electron emitter;

and

said electron emitter comprises an emitter of a dielectric material and a first electrode and a second electrode which are disposed on said emitter;

wherein when a drive voltage is applied between said first electrode and said second electrode, at least a portion of said emitter has its polarization inverted or changed to emit electrons.

16. A light source according to claim 15, wherein when said drive voltage is applied between said first electrode and said second electrode, at least said portion of said emitter has its polarization inverted to position positive poles of dipoles around said first electrode to draw primary electrons from said first electrode, and said primary electrons drawn from said first electrode impinge upon said emitter to cause said emitter to emit secondary electrons.

17. A light source according to claim 16, including:

a triple point made up of said first electrode, said emitter, and a vacuum atmosphere;

wherein said primary electrons are drawn from a portion of said first electrode near said triple point, and said primary electrons drawn from said first electrode impinge upon said emitter to cause said emitter to emit secondary electrons.

18. A light source according to claim 15, including:

means for applying AC pulses between said first electrode and said second electrode to cause at least said portion of said emitter to have its polarization inverted or changed;

wherein electrons are intermittently emitted from said emitter.

19. A light source according to claim 18, wherein before light emitted by a first emission of electrons is extinguished, next electrons are emitted to emit light continuously.

20. A light source according to claim 15, including:

a plurality of said electron emitters, said electron emitters being arranged in a two-dimensional array.

21. A light source according to claim 15, including:

means for modulating said drive voltage based on a control signal to control an amount of electrons emitted from said electron emitter for controlling emitted light.

22. A light source of a discharge lamp type, wherein

electrons ignite or assist in an electric discharge;

a source of said electrons comprises an electron emitter; and

said electron emitter comprises an emitter of a dielectric material and a first electrode and a second electrode to which a drive voltage is applicable to emit electrons from said emitter;

said first electrode being disposed on a first surface of said emitter;

said second electrode being disposed on a second surface of said emitter;

at least said first electrode having a plurality of through regions through which said emitter is exposed; and

each of said through regions has a peripheral portion having a surface facing said emitter and spaced from said emitter.

23. A light source according to claim 22, wherein said first electrode emits electrons toward said emitter to charge said emitter in a first stage;

and

said emitter emits electrons in a second stage.

24. A light source according to claim 22, wherein electrons depending on an amount of charges on said emitter in a first stage are emitted from said emitter in a second stage.

25. A light source according to claim 22, wherein an amount of charges on said emitter in a first stage is maintained until electrons are emitted from said emitter in a second stage.

26. A light source according to claim 22, wherein said emitter is made of a piezoelectric material, an anti-ferroelectric material, or an electrostrictive material.

27. A light source according to claim 22, including:

means for applying AC pulses between said first electrode and said second electrode to cause at least said portion of said emitter to have its polarization inverted or changed;

wherein electrons are intermittently emitted from said emitter.

28. A light source according to claim 27, wherein before light emitted by a first emission of electrons is extinguished, next electrons are emitted to emit light continuously.

29. A light source according to claim 22, including:

a plurality of said electron emitters, said electron emitters being arranged in a two-dimensional array.

30. A light source according to claim 22, including:

means for modulating said drive voltage based on a control signal to control an amount of electrons emitted from said electron emitter for controlling emitted light.

31. A light source for emitting light by exciting a phosphor with an ultraviolet radiation generated from a gas sealed in a space in said light source, wherein

electrons assist in generating said ultraviolet radiation from said gas;

a source of said electrons comprises an electron emitter; and

said electron emitter comprises an emitter of a dielectric material and a first electrode and a second electrode to which a drive voltage is applicable to emit electrons from said emitter;

said first electrode being disposed on a first surface of said emitter;

said second electrode being disposed on a second surface of said emitter;

at least said first electrode having a plurality of through regions through which said emitter is exposed; and

each of said through regions has a peripheral portion having a surface facing said emitter and spaced from said emitter.

32. A light source according to claim 31, wherein said first electrode emits electrons toward said emitter to charge said emitter in a first stage;

and

said emitter emits electrons in a second stage.

33. A light source according to claim 31, wherein electrons depending on an amount of charges on said emitter in a first stage are emitted from said emitter in a second stage.

34. A light source according to claim 31, wherein an amount of charges on said emitter in a first stage is maintained until electrons are emitted from said emitter in a second stage.

35. A light source according to claim 31, wherein said emitter is made of a piezoelectric material, an anti-ferroelectric material, or an electrostrictive material.

36. A light source according to claim 31, including:

means for applying AC pulses between said first electrode and said second electrode to cause at least said portion of said emitter to have its polarization inverted or changed;

wherein electrons are intermittently emitted from said emitter.

37. A light source according to claim 36, wherein before light emitted by a first emission of electrons is extinguished, next electrons are emitted to emit light continuously.

38. A light source according to claim 31, including:

a plurality of said electron emitters, said electron emitters being arranged in a two-dimensional array.

39. A light source according to claim 31, including:

means for modulating said drive voltage based on a control signal to control an amount of electrons emitted from said electron emitter for controlling emitted light.

40. A light source for emitting light from a phosphor by having electrons and/or ions impinge upon the phosphor, said electrons and/or ions being produced when electrons impinge upon molecules of a gas sealed in a space in said light source and ionize said molecules of the gas, wherein

a source of said electrons comprises an electron emitter;

and

said electron emitter comprises an emitter of a dielectric material and a first electrode and a second electrode to which a drive voltage is applicable to emit electrons from said emitter;

said first electrode being disposed on a first surface of said emitter;

said second electrode being disposed on a second surface of said emitter;

at least said first electrode having a plurality of through regions through which said emitter is exposed; and

each of said through regions has a peripheral portion having a surface facing said emitter and spaced from said emitter.

41. A light source according to claim 40, wherein said first electrode emits electrons toward said emitter to charge said emitter in a first stage;

and

said emitter emits electrons in a second stage.

42. A light source according to claim 40, wherein electrons depending on an amount of charges on said emitter in a first stage are emitted from said emitter in a second stage.

43. A light source according to claim 40, wherein an amount of charges on said emitter in a first stage is maintained until electrons are emitted from said emitter in a second stage.

44. A light source according to claim 40, wherein said emitter is made of a piezoelectric material, an anti-ferroelectric material, or an electrostrictive material.

45. A light source according to claim 40, including:

means for applying AC pulses between said first electrode and said second electrode to cause at least the portion of said emitter to have its polarization inverted or changed;

wherein electrons are intermittently emitted from said emitter.

46. A light source according to claim 45, wherein before light emitted by a first emission of electrons is extinguished, next electrons are emitted to emit light continuously.

47. A light source according to claim 40, including:

a plurality of said electron emitters, said electron emitters being arranged in a two-dimensional array.

48. A light source according to claim 40, including:

means for modulating said drive voltage based on a control signal to control an amount of electrons emitted from said electron emitter for controlling emitted light.