US4100570A
Expired / Lapsed
US
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Optical image pickup system
Assignee: Hitachi Ltd
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Filing: 1976-02-24
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Granted: 1978-07-11
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Expires: 1996-02-24
Abstract
Abstract An optical image pickup system for reducing spurious color signals generated in an image pickup system including a stripe-shaped color separation or color encoding filter, wherein a double refraction plate and a diffraction grating spatial frequency filter are arranged serially in an optical path to maintain a high resolution power in the luminance band and at the same time present a sufficient reduction of the spurious color signal.
Inventors
- 👤 Saburo Nobutoki
- 👤 Yukio Okano
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 02:34
CPC Classifications
H; H01; H01J; H01J29/00; H01J29/86; H01J29/89; G; G02; G02B; G02B27/00; G02B27/42; G02B27/46
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
61 words
An optical image pickup system having an optical transfer function including a stripe-shaped color separation filter, comprising at least one double refraction plate and at least one diffraction grating spatial frequency filter arranged serially in an optical image pickup path, thereby reducing the optical transfer function of said optical image pickup system in at least the chromaticity band spatial frequency range.
Claim 2
Dependent Claim
61 words
An optical image pickup system having an optical transfer function including a stripe-shaped color separation filter, comprising at least one double refraction plate and at least one diffraction grating spatial frequency filter arranged serially in an optical image pickup path, thereby reducing the optical transfer function of said optical image pickup system in at least the chromaticity band spatial frequency range.
Claim 3
Dependent Claim
23 words
An optical image pickup system according to claim 1, wherein said optical transfer function R(f) in said chromaticity band is defined by R(f)≦0.2.
Claim 4
Dependent Claim
56 words
An optical image pickup system according to claim 2, wherein the optical transfer function R(f 2 ) at the upper limit frequency f 2 in said chromaticity band is smaller than or equal to the optical transfer function R(f 1 ) at the lower limit frequency f 1 in said chromaticity band, i.e., R(f.sub.1) ≧ R(f.sub.2).
Claim 5
Dependent Claim
34 words
An optical image pickup system according to claim 2 wherein the optical transfer function R(f 1 ) at the lower limit frequency in said chromaticity band is defined by R(f 1 ) ≧ 0.1.
Claim 6
Dependent Claim
29 words
An optical image pickup system according to claim 1 wherein said double refraction plate is arranged closer to the image pickup tube than said diffraction grating spatial frequency filter.
Claim 7
Dependent Claim
24 words
An optical image pickup system according to claim 1 wherein said diffraction grating spatial frequency filter is built in an image pickup lens system.
Claim 8
Dependent Claim
32 words
An optical image pickup system according to claim 1 wherein said double refraction plate is made of a material selected from a group essentially consisting of quartz, calcite and LiNbO 3 .
Claim 9
Dependent Claim
30 words
An optical image pickup system according to claim 1 wherein said double refraction plate comprises two materials selected from a group essentially consisting of quartz, calcite and LiNbO 3 .
Claim 10
Dependent Claim
20 words
An optical image pickup system according to claim 8 wherein said diffraction grating spatial frequency filter is a one-dimensional array.
Claim 11
Dependent Claim
20 words
An optical image pickup system according to claim 8 wherein said diffraction grating spatial frequency filter is a two-dimensional array.
Claim 12
Dependent Claim
20 words
An optical image pickup system according to claim 8 wherein said diffraction grating spatial frequency filter is a random array.
Claim 13
Dependent Claim
22 words
An optical image pickup system according to claim 1 wherein said diffraction grating spatial frequency filter is a square wave phase grating.
Claim 14
Dependent Claim
22 words
An optical image pickup system according to claim 1 wherein said diffraction grating spatial frequency filter is a sine wave phase grating.
Claim 15
Dependent Claim
78 words
An optical image pickup system including a stripe-shaped color separation filter, comprising at least one double refraction plate and at least one diffraction grating spatial frequency filter arranged serially in an optical image pickup path, an overall optical transfer function R(f) representative of the product of an optical transfer function of said double refraction plate and an optical transfer function of said diffraction grating spatial frequency filter being determined as R(f)≦0.2 in a chromaticity band spatial frequency range.
Claim 16
Dependent Claim
78 words
An optical image pickup system including a stripe-shaped color separation filter, comprising at least one double refraction plate and at least one diffraction grating spatial frequency filter arranged serially in an optical image pickup path, an overall optical transfer function R(f) representative of the product of an optical transfer function of said double refraction plate and an optical transfer function of said diffraction grating spatial frequency filter being determined as R(f)≦0.2 in a chromaticity band spatial frequency range.
References Cited (Backward Citations)
US3910683A
Cited
US3940788A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-07-10 | 1982-01-09 | 1982-07-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-07-10 | 1986-01-09 | 1986-07-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-07-10 | 1990-01-09 | 1990-07-11 | $7700.00 | Window Closed / Lapsed |