Fine-line diffractive subtractive color filters
First Claim
1. In a fine-line rectangular-profile diffractive subtractive filter surrounded by a medium having an index of refraction n1 and responsive to the illumination thereof with unpolarized white light for deriving zero diffraction order output light exhibiting a single one of the group of colors consisting of cyan, magenta, yellow and green, wherein said filter has a given line spacing d and said rectangular-profile has a given aspect ratio b and a given optical depth a;
- the improvement;
wherein the respective values of n1 d and b define a point within a certain one of plot areas 200, 202, 204, 206 and 208 of FIG. 2.
0 Assignments
0 Petitions
Accused Products
Abstract
Rectangular groove profile grating, having an effective line spacing no greater than 2μm, has grating parameters specified to provide at least acceptable or, preferably, good zero diffraction order color characteristics for subtractive primary colors and green when grating is illuminated with unpolarized white light.
20 Citations
40 Claims
-
1. In a fine-line rectangular-profile diffractive subtractive filter surrounded by a medium having an index of refraction n1 and responsive to the illumination thereof with unpolarized white light for deriving zero diffraction order output light exhibiting a single one of the group of colors consisting of cyan, magenta, yellow and green, wherein said filter has a given line spacing d and said rectangular-profile has a given aspect ratio b and a given optical depth a;
- the improvement;
wherein the respective values of n1 d and b define a point within a certain one of plot areas 200, 202, 204, 206 and 208 of FIG. 2. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38)
- the improvement;
- 2. The filter defined in claim 2, wherein said single one of the colors is green, and wherein the respective values of n1 d and b define a point within a certain one of plot areas 200 and 202 of FIG. 2.
-
39. In a fine-line rectangular-profile diffraction subtractive filter surrounded by a medium having an index of refaction n1 and responsive to the illumination thereof with unpolarized white light for deriving zero diffraction order output light;
- the improvement;
wherein said filter over a first region thereof has a line spacing multiplied by n1 of substantially 1.4μ
m, an aspect ratio of substantially 0.3 and an optical amplitude of substantially 460nm, whereby said output light from said first region exhibits a cyan color,wherein said filter over a second region thereof has a line spacing multiplied by n1 of substantially 1.4μ
m, an aspect ratio of substantially 0.3 and an optical amplitude of substantially 710nm, whereby said output light from said second region exhibits a yellow color andwherein said filter over a third region thereof has a line spacing of multiplied by n1 of substantially 1.4μ
m, an aspect ratio of substantially 0.3 and an optical amplitude of substantially 1200nm whereby said output light from said third region exhibits a green color.
- the improvement;
-
40. In a fine-line rectangular-profile diffraction subtractive filter surrounded by a medium having an index of refraction n1 and responsive to the illumination thereof with unpolarized white light for deriving zero diffraction order output light;
- the improvement;
wherein said filter over a first region thereof has a line spacing multiplied by n1 of substantially 1.4μ
m, an aspect ratio of substantially 0.325 and an optical amplitude of substantially 430nm, whereby said output light from said first region exhibits a cyan color,wherein said filter over a second region thereof has a line spacing multiplied by n1 of substantially 1.4μ
m, an aspect ratio of substantially 0.325 and an optical amplitude of substantially 710nm whereby said output light from said second region exhibits a yellow color, andwherein said filter over a third region thereof has a line spacing multiplied by n1 of substantially 1.4μ
m, an aspect rationof substantially 0.325 and an optical amplitude of substantially 1180 whereby said output light from said third region exhibits a green color.
- the improvement;
Specification