CATHODE-RAY TUBE WITH SCREEN COMPRISING LASER CRYSTALS

• US 3,575,627 A
• Filed: 12/29/1967
• Issued: 04/20/1971
• Est. Priority Date: 12/29/1967
• Status: Expired due to Term

• Current Assignee: RCA Corporation
• Original Assignee: Frederick H. Nicoll
• Inventors: Nicoll, Frederick H.
• Application Number:
  US04/694,666
• Time in Patent Office: 1,208 Days
• US Class Current: 313/467
• CPC Class Codes: H01J 29/10 Screens on or from which an image or pattern is formed, picked up, converted or stored
• CPC Class Codes: H01S 3/0959 by an electron beam

Abstract

A cathode-ray tube has a screen comprising an array of laser crystals, in which the individual laser crystals emit coherent light in a narrow disclike beam when excited by an electron beam.

Claims

2. A cathode-ray tube as described in claim 1 wherein said laser crystals are hexagonal crystals of a material chosen from the group consisting of zinc oxide, zinc sulfide and cadmium sulfide.

3. A cathode-ray tube as described in claim 2 wherein said hexagonal laser crystals are arranged on said screen with their C axes parallel.

4. A cathode-ray tube as described in claim 1 wherein said laser crystals consist of gallium arsenide.

5. A cathode-ray tube as described in claim 4 wherein said laser crystals are arranged on said screen with their long axes parallel.

6. A cathode-ray tube as described in claim 1 wherein said laser crystals are less than 100 microns in thickness.

7. A cathode-ray tube as described in claim 1 wherein said array therefor of laser crystals comprises a mixture of laser crystals composed of different materials, said crystals being chosen to emit light at different respective frequencies.

8. A cathode-ray tube as described in claim 1, wherein said laser crystals are adapted to emit light at a relatively narrow angle.

9. A cathode-ray tube as described in claim 1 wherein each one of said laser crystals is adapted to emit light in a broad angle in at least one plane.

10. A cathode-ray tube as described in claim 9 wherein said broad angle is substantially 360* .

11. A cathode-ray tube as described in claim 9 wherein said crystals are elongated and said plane is substantially perpendicular to the respective major axes of said crystals.

12. A cathode-ray tube as described in claim 11 wherein said crystal has a hexagonal crystallographic structure and said major axes are the respective C axes of said crystals.

13. A cathode-ray tube aS described in claim 9, wherein said screen is adapted to emit light at an angle of substantially 180* and comprises means for causing substantially all of said emitted light to pass through said faceplate.

14. A cathode-ray tube as described in claim 13 wherein said means includes:

a first thin layer of a reflecting material adjacent to said crystals.

15. A cathode-ray tube as described in claim 1 wherein said target structure further includes:

a second thin layer of a material having an index of refraction lower than the index of refraction of said laser crystals between said screen and said first thin layer.