Tri-color separating optical system
First Claim
1. A tri-color separating optical system for separating an optical image of a subject into three different color optical images, which comprises:
- (a) focusing means for focusing the subject optical image on a first optical image forming plane (Ig);
(b) dichroic reflecting means, optically coupled to said focusing means, for directly passing a first color optical image therethrough and reflecting a second color optical image in a first direction therefrom, and a third color optical image in a second direction opposite to the first direction therefrom;
(c) first optical block means having therein a first total reflection surface optically coupled to said dichroic reflecting means and causing a first extended optical path length, for reflecting the second color optical image reflected from said dichroic reflecting means in the first direction to a second optical image forming plane (Ib) through the first extended optical path length; and
(d) second optical block means having therein a second total reflection surface optionally coupled to said dichroic reflecting means and causing a second extended optical path length, for reflecting the third color optical image reflected from said dichroic reflecting means in the second direction to a third optical image forming plane (Ir) through the second extended optical path length;
the first, second and third different-color optical image forming planes (Ig, Ib, Ir) being aligned with each other in close vicinity on a single plane.
2 Assignments
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Accused Products
Abstract
To form three different color optical images in close vicinity to each other on the same image forming plane in a tri-color separating optical system, the optical system comprising a lens for focusing a subject optical image on a green optical image forming plane (Ig); dichroic mirrors or a dichroic prism for directly passing a green color image and reflecting a blue color image in the first direction and a red color image in the second direction; a first prism having therein a total reflection surface and an extended optical path length for reflecting the blue color image to a blue optical image-forming plane (Ib); and a second prism having therein a total reflection surface and an extended optical path length for reflecting the red color image to a red optical image-forming plane (Ir).
51 Citations
8 Claims
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1. A tri-color separating optical system for separating an optical image of a subject into three different color optical images, which comprises:
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(a) focusing means for focusing the subject optical image on a first optical image forming plane (Ig); (b) dichroic reflecting means, optically coupled to said focusing means, for directly passing a first color optical image therethrough and reflecting a second color optical image in a first direction therefrom, and a third color optical image in a second direction opposite to the first direction therefrom; (c) first optical block means having therein a first total reflection surface optically coupled to said dichroic reflecting means and causing a first extended optical path length, for reflecting the second color optical image reflected from said dichroic reflecting means in the first direction to a second optical image forming plane (Ib) through the first extended optical path length; and (d) second optical block means having therein a second total reflection surface optionally coupled to said dichroic reflecting means and causing a second extended optical path length, for reflecting the third color optical image reflected from said dichroic reflecting means in the second direction to a third optical image forming plane (Ir) through the second extended optical path length;
the first, second and third different-color optical image forming planes (Ig, Ib, Ir) being aligned with each other in close vicinity on a single plane. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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3. The tri-color separating optical system of claim 1, wherein said focusing means is an image pickup convex lens.
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4. The tri-color separating optical system of claim 1, wherein said dichroic reflecting means is a dichroic mirror composed of a first mirror for reflecting only the blue color optical image and passing through the red and green color optical images and a second mirror for reflecting only the red color optical image and passing through the blue and green color optical images.
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5. The tri-color separating optical system of claim 1, wherein said dichroic reflecting means is a dichroic prism having a first dichroic mirror surface for reflecting only the blue color optical image and passing through the red and green color optical images and a second dichroic mirror surface for reflecting only the red color optical image and passing through blue and green color optical images.
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6. The tri-color separating optical system of claim 1, wherein said first and second optical block means are first and second prisms each formed with a total reflection surface and an extended optical path length, respectively.
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7. A color image pickup apparatus, comprising:
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(a) a tri-color separating optical system for separating an optical image of a subject into three different color optical images, as recited in claim 1; and (b) photoelectric transducing elements arranged on the first, second and third different color optical image forming planes, respectively.
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8. A tri-color separating optical system for separating an optical image of a subject into three different color optical images, which comprises:
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(a) focusing means for focusing the subject optical image on a first optical image forming plane (Ig); (b) dichroic reflecting means, optically coupled to said focusing means, for directly passing a first color optical image therethrough and reflecting a second color optical image in a first direction therefrom, and a third color optical image in a second direction opposite to the first direction therefrom; (c) first optical block means having therein a first total reflection surface optically coupled to said dichroic reflecting means and causing a first extended optical path length, for reflecting the second color optical image reflected from said dichroic reflecting means in the first direction to a second optical image forming plane (Ib) through the first extended optical path length; and (d) second optical block means having therein a second total reflection surface optically coupled to said dichroic reflecting means and causing a second extended optical path length, for reflecting the third color optical image reflected from said dichroic reflecting means in the second direction to a third optical image forming plane (Ir) through the second extended optical path length;
the first, second and third different-color optical image forming planes (Ig, Ib, Ir) being aligned with each other in close vicinity on a single plane, wherein;
the first or second extended optical path length is determined in accordance with a formula as
space="preserve" listing-type="equation">x=d(n-1)nwhere x denotes an extended amount of optical path length;
d denotes an optical path length of said first or second optical block means; and
n denotes a refraction index of material of said optical block means.
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Specification