Abstract An optical low-pass filter so formed that a rectangular wave phase grating including a plurality of sets of laminae for introducing phase retardation, in which laminae in each set being arranged in parallel with each other and the laminae of different sets being arranged to cross with an angle to each other is inserted in an optical system of the type having a color-encoding filter means disposed in the light path of the optical system for, such as, a single tube color television camera, and high frequency components of an objective image on the color-encoding filter means are attenuated less than a predetermined level, to the image focused on the color-encoding filter means, a degree of blur always larger than the value calculated from the grating period of the color-encoding filter means is given and another image focused on a position distant from said image as far as a predetermined distance brings about no interference to produce another color striped pattern with said color-encoding filter means, regardless of f-number of the objective lens and the diaphragm value so as to remove the influence effected by interference between the luminance and chrominance signal.
Inventors
👤 H Nishino
👤 I Hioki
Bibliographic Details
Application Number—
JurisdictionUS
Data Sourcegoogle_patents
Last Synchronized2026-10-24 14:30
CPC Classifications
G; G02; G02B; G02B27/00; G02B27/42; G02B27/46
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
134 words
In an optical system for introducing an image of an object scene to an image tube in a color television system and having a color encoding filter means disposed in the lightpath of said optical system and serving to spacially modulate at least two of three primary color images, the optical system comprising optical low pass filter means disposed between said object scene and said color encoding filter and including a plurality of sets of laminae for introducing phase retardation, laminae in each set being arranged in parallel with each other and disposed at an angle to the laminae of at least one other set, and laminae in one of the sets being so arranged to attenuate beats effected by interrelation between said color encoding filter and high frequency components in said object scene.
Claim 2
Dependent Claim
134 words
In an optical system for introducing an image of an object scene to an image tube in a color television system and having a color encoding filter means disposed in the lightpath of said optical system and serving to spacially modulate at least two of three primary color images, the optical system comprising optical low pass filter means disposed between said object scene and said color encoding filter and including a plurality of sets of laminae for introducing phase retardation, laminae in each set being arranged in parallel with each other and disposed at an angle to the laminae of at least one other set, and laminae in one of the sets being so arranged to attenuate beats effected by interrelation between said color encoding filter and high frequency components in said object scene.
Claim 3
Dependent Claim
34 words
An optical system as set forth in claim 1, wherein said low-pass filter further comprises a transparent base plate on which said plurality of sets of laminae are mounted in combination with each other.
Claim 4
Dependent Claim
27 words
An optical system as set forth in claim 1, wherein each set of laminae is respectively mounted on a transparent base plate to form a low-pass filter.
Claim 5
Dependent Claim
33 words
An optical system as set forth in claim 3, further comprising an objective lens on both sides of which the low-pass filters are disposed perpendicularly to the optical axis of the objective lens.
Claim 6
Dependent Claim
39 words
An optical system as set forth in claim 1, wherein each lamina is rectangular in cross section, and each set of laminae is mounted on a transparent base plate in the form of a rectangular wave phase diffraction grating.