STRIPED DICHROIC FILTER AND METHOD FOR MAKING THE SAME

• US 3,771,857 A
• Filed: 04/19/1971
• Issued: 11/13/1973
• Est. Priority Date: 04/19/1971
• Status: Expired due to Term

• Current Assignee: David G. Thomasson, Frederick K. Crosher, Leroy A. Bartolmei, Michael D. Temple, Richard Ian Seddon
• Original Assignee: David G. Thomasson, Frederick K. Crosher, Leroy A. Bartolmei, Michael D. Temple, Richard Ian Seddon
• Inventors: Seddon, Richard Ian, Thomasson, David G., Crosher, Frederick K., Temple, Michael D., Bartolmei, Leroy A.
• Primary Examiner(s): Wibert, Ronald L.
• Application Number:
  US05/135,131
• Time in Patent Office: 939 Days
• Field of Search: 350/163-166,316,317
• US Class Current: 359/587
• CPC Class Codes: G02B 5/201 in the form of arrays
• CPC Class Codes: G02B 5/285 comprising deposited thin solid films G02B5/281 - G02B5/289 take precedence; multilayered film filters for fibre optic multiplexing G02B6/29361
• CPC Class Codes: G03B 33/00 Colour photography, other than mere exposure or projection of a colour film printing apparatus G03B27/00; stereoscopic colour photography G03B35/00

Abstract

Striped dichroic filter having a substantially transparent glass substrate with a surface and having first and second sets of spaced parallel stripes disposed on said surface at an angle with respect to each other and with each of said sets of stripes being capable of reflecting at least one different color and with the stripes being formed of a plurality of layers of high and low index dielectric materials. In the method for making a striped dichroic filter, first and second sets of spaced parallel stripes are sequentially formed by sequentially depositing dielectric coating materials on sequentially formed stripe material which is subsequently etched away to remove the undesired portions of the coating material so that there remains first and second sets of spaced parallel stripes at angles with respect to each other and with each being capable of reflecting at least one different color.

Claims

1. In a striped dichroic filter, a substantially transparent glass substrate having a surface, a first set of spaced parallel stripes for reflecting at least one color, and a second set of spaced parallel stripes for reflecting at least one color different from said one color reflected by said first set of stripes, said first and second sets of stripes being disposed on said surface at an angle with respect to each other with the first and second sets overlying each other on certain areas of said surface, each of said stripes being formed of a plurality of layers of high and low index dielectric materials.

2. A filter as in claim 1 wherein said stripes are are formed with an outermost layer of a dielectric to permit cleaning of said filter.

3. A filter as in claim 1 wherein said first set of stripes is formed to reflect red and wherein said second set of stripes is capable of reflecting blue.

4. A filter as in claim 3 wherein said stripes of said first set of stripes includes a red reflecting stack which reflects from approximately 590 to 750 nanometers together with anti-reflection layers disposed on opposite sides of the red reflecting stack.

5. A filter as in claim 3 wherein each of said stripes of said second set of stripes includes a blue reflecting stack reflecting from approximately 380 to 485 nanometers and an anti-reflection coating disposed on each side of the blue reflecting stack.

6. A filter as in claim 1 together with a third set of spaced parallel stripes carried on said surface at an angle with respect to said first and second sets for transmitting at least one color different from said one colors reflected by said first and second sets.

7. A filter as in claim 6 wherein each of said stripes of said third set of stripes includes a green transmitting stack transmitting from approximately 505 to 585 nanometers and anti-reflection layers disposed on each side of the green transmitting stack.

8. A filter as in claim 4 wherein said high index material is titanium dioxide and said low index material is a quartz-like material.

9. A filter as in claim 6 wherein said high index material is zirconium oxide and said low index material is a quartz-like material.

10. A filter as in claim 1 wherein said stripes of each set have a thickness in excess of one micron.