Apparatus for generating light by utilizing microwave

• US 4,933,602 A
• Filed: 02/12/1988
• Issued: 06/12/1990
• Est. Priority Date: 03/11/1987
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Murayama, Seiichi, Sekine, Kenji, Ono, Tetsuo
• Primary Examiner(s): Laroche, Eugene R.
• Assistant Examiner(s): NOT, DEFINED
• Application Number:
  US07/155,507
• Time in Patent Office: 851 Days
• Field of Search: 315/39, 315/248, 315/111.21, 315/111.31, 315/344, 315/267, 313/231.31, 313/231.41, 250/504 R, 250/493.1
• US Class Current: 315/39
• CPC Class Codes: H01J 65/04 Lamps in which a gas filling is excited to luminesce by an external electromagnetic field or by external corpuscular radiation, e.g. for indicating plasma display panels

Abstract

A light source apparatus for irradiating a large area with high intensity of light comprises a microwave cavity having a section of a flat shape and a plurality of electrodeless lamps disposed within the cavity in juxtaposition with one another in a flat array.

Claims

1. A light source apparatus, comprising:

means for generating microwaves of a predetermined wavelength;

microwave transmitting means having one end coupled to said microwave generating means for transmitting the generated microwaves;

a cavity coupled to the other end of said microwave transmitting means; and

a plurality of electrodeless lamps juxtaposed with one another within said cavity in a flat array;

wherein said cavity is a rectangular parallelepiped of flat configuration, opaque to said microwaves, having length, width and thickness dimensions, wherein said thickness is less than 1/2 of the wavelength of said microwaves, and includes a mesh-like portion transparent to light emitted from said lamps.

2. A light source apparatus according to claim 1, wherein each of said lamps has a portion projecting outwardly from said cavity.

3. A light source apparatus according to claim 1, wherein microwave input energy per unit volume of said lamp is at least 0.73 W/cm³.

4. A light source apparatus according to claim 1, wherein said cavity is coupled to said microwave transmitting means through a hole having an area of at least 12 cm² and formed in one side of said cavity.

5. A light source apparatus according to claim 2, wherein said cavity is coupled to said microwave transmitting means through a hole having an area of at least 12 cm² and formed in one side of said cavity.

6. A light source apparatus according to claim 3, wherein said cavity is coupled to said microwave transmitting means through a hole having an area of at least 12 cm² and formed in one side of said cavity.

7. A light source apparatus according to claim 4, wherein said cavity is coupled to said microwave transmitting means through a hole having an area of at least 12 cm² and formed in one side of said cavity.

8. A light source apparatus according to claim 1, wherein said cavity is coupled to said microwave transmitting means through a hole having an area of at least 4.5% of that of a top side face of said cavity and formed in said top side face.

9. A light source apparatus according to claim 8, wherein said hole is apertured over at least 3/4 of the length of an area covered by said lamps in the axial direction of said microwave transmitting means.

10. A light source apparatus according to claim 8, wherein said hole has a width equal to at least 3/10 of a long side of a section of said microwave transmitting means.

11. A light source apparatus, comprising:

means for generating microwaves of a predeermined wavelength;

microwave transmitting means having one end coupled to said microwave generating means for transmitting the generated microwaves;

a cavity coupled to the other end of said microwave transmitting means; and

a plurality of lamps juxtaposed with one another within said cavity in a flat array;

said cavity being in the form of a rectangular parallelpiped having length, width and thickness dimensions, wherein said thickness is less than 1/2 of the wavelength of said microwaves, said cavity further being opaque to light emitted from said lamps and including a mesh-like portion transparent to light emitted from said lamps, and wherein the input microwave energy per unit volume of said lamp is at least 0.73 W/cm³.

12. A light source apparatus, comprising:

means for generating microwaves of a predetermined wavelength;

microwave transmitting means having one end coupled to said microwave generating means for transmitting the generated microwaves;

a cavity coupled to the other end of said microwave transmitting means; and

a plurality of lamps juxtaposed with one another within said cavity in a flat array;

said cavity being in the form of a rectangular parallelepiped having length, width, and thickness dimensions wherein said thickness is less than 1/2 of the wavelength of said microwaves, said cavity further being opaque to light emitted from said lamps and including a mesh-like portion transparent to light emitted from said lamps, and wherein each of said lamps has a portion projecting outwardly from said cavity.

13. A light source apparatus, comprising:

means for generating microwaves of a predetermined wavelength;

microwave transmitting means having one end coupled to said microwave generating means for transmitting the generated microwaves;

a cavity coupled to the other end of said microwave transmitting means; and

a plurality of lamps juxtaposed with one another within said cavity in a flat array;

said cavity being in the form of a rectangular parallelepiped having length, width and thickness dimensions, wherein said thickness is less than 1/2 of the wavelength of said microwaves, being opaque to light emitted from said lamps, and including a mesh-like portion transparent to light emitted from said lamps, wherein each of said lamps has a portion projecting outwardly from said cavity, and further wherein the input microwave energy per unit volume of said lamp is at least 0.73 w/cm³.