Patent EP0122783A2 successfully refreshed from Google Patents.
EP0122783A2
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Method and apparatus for light beam scanning using a hologram
Assignee: Fujitsu Ltd
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Filing: 1984-04-13
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Granted: —
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Expires: 2004-04-13
Abstract
Abstract A method for constructing a hologram on a transparent disk (11) comprising the steps of: irradiating a referencewave light beam having a diverging spherical wave front from a first point light source located at a predetermined distance (f A ) on a center axis (12) of the transparent disk, irradiating an object wave light beam having a diverging spherical wavefrontfrom a second point light source located at a predetermined distance (fs) on a normal line (13) located a predetermined distance (R) from the center axis, causing interference between the reference wave light beam from the first point light source and the object wave light beam from the second point light source on the transparent disk, and forming interference fringes, having spatial variation of spatial frequency including a maximum, as a hologram on the disk, wherein, a reconstruction beam is irradiated to a position (P 3 ) on the disk in the vicinity of the maximum.
Inventors
- 👤 Fumio Yamagishi
- 👤 Shinya Hasegawa
- 👤 Hiroyuki Ikeda
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 19:07
CPC Classifications
G; G06; G06K; G06K15/00; G06K15/02; G06K15/12; G06K15/1285; G02; G02B; G02B26/00; G02B26/08; G02B26/10; G02B26/106
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
158 words
A method for constructing a hologram on a transparent disk comprising the steps of: first irradiating a reference wave light beam as a construction wave light beam having a diverging spherical wave front from a first point light source located at a predetermined distance on a center axis, or in the vicinity of the center axis of said transparent disk, second irradiating an object wave light beam as a construction wave light beam having a diverging spherical wave front from a second point light source located at a predetermined distance on a normal line located a predetermined distance from said center axis, causing interference between said . reference wave light beam irradiated by said first point light source and said object wave light beam irradiated by said second point light source on said transparent disk, and forming interference fringes having a spatial variation of spatial frequency, said variation including a minimum of rate of change of spatial frequency.
Claim 2
Independent Claim
158 words
A method for constructing a hologram on a transparent disk comprising the steps of: first irradiating a reference wave light beam as a construction wave light beam having a diverging spherical wave front from a first point light source located at a predetermined distance on a center axis, or in the vicinity of the center axis of said transparent disk, second irradiating an object wave light beam as a construction wave light beam having a diverging spherical wave front from a second point light source located at a predetermined distance on a normal line located a predetermined distance from said center axis, causing interference between said . reference wave light beam irradiated by said first point light source and said object wave light beam irradiated by said second point light source on said transparent disk, and forming interference fringes having a spatial variation of spatial frequency, said variation including a minimum of rate of change of spatial frequency.
Claim 3
Dependent Claim
53 words
A method as claimed in claim 1, wherein, said first irradiating and said second irradiating are performed by said first point light source and said second point light source located at a position symmetrical with respect to a normal line on a point of which a reconstruction beam is irradiated to said hologram.
Claim 4
Dependent Claim
41 words
A method of reconstructing a hologram constructed according to the method of claim 1 or claim 2, wherein a reconstruction beam is directed to a point at, or in the vicinity of, said minimum of rate of change of spatial frequency.
Claim 5
Dependent Claim
27 words
A method as claimed in claim 3, wherein, the wavelength of said construction wave light beam is longer than the wavelength of said reconstruction wave light beam.
Claim 6
Independent Claim
89 words
A method for scanning a light beam comprising the steps of: irradiating a hologram obtained by interference of a reference wave light beam having one diverging spherical wave front and an object wave light beam having another diverging spherical wave front with a reconstruction beam, and moving said hologram, thereby obtaining a scanning light beam, being said reconstruction beam/irradiated to points corresponding to a position at, or in the vicinity of which, the spatial rate of change of spatial frequency of interference fringes of said hologram is a minimum.
Claim 7
Independent Claim
89 words
A method for scanning a light beam comprising the steps of: irradiating a hologram obtained by interference of a reference wave light beam having one diverging spherical wave front and an object wave light beam having another diverging spherical wave front with a reconstruction beam, and moving said hologram, thereby obtaining a scanning light beam, being said reconstruction beam/irradiated to points corresponding to a position at, or in the vicinity of which, the spatial rate of change of spatial frequency of interference fringes of said hologram is a minimum.
Claim 8
Independent Claim
108 words
An apparatus for scanning a light beam comprising: a hologram obtained by interference of a reference wave light beam and an object wave light beam, a light beam source operable to generate a reconstruction beam for irradiating said hologram, and shifting means for shifting said hologram thereby obtaining a scanning light beam, characterised in that both said reference wave light beam and said object wave light beam have a - diverging spherical wave front, and said reconstruction beam being irradiated to a point at, or in the vicinity of, a position where the rate of change of spatial frequency of interference fringes of said hologram, is a minimum.
Claim 9
Independent Claim
108 words
An apparatus for scanning a light beam comprising: a hologram obtained by interference of a reference wave light beam and an object wave light beam, a light beam source operable to generate a reconstruction beam for irradiating said hologram, and shifting means for shifting said hologram thereby obtaining a scanning light beam, characterised in that both said reference wave light beam and said object wave light beam have a - diverging spherical wave front, and said reconstruction beam being irradiated to a point at, or in the vicinity of, a position where the rate of change of spatial frequency of interference fringes of said hologram, is a minimum.
Claim 10
Dependent Claim
21 words
An apparatus for scanning a light beam as claimed in claim 6, wherein said apparatus is used as a laser printer.
Claim 11
Independent Claim
80 words
An apparatus for producing a scanning light beam, comprising a hologram, a light beam source operable to generate a reconstruction beam, and means for moving the hologram relative to the reconstruction beam, wherein the hologram has interference fringes having a spatial variation of spatial frequency, said variation including a minimum of rate of change of spatial frequency, the apparatus being arranged to direct said reconstruction beam to points corresponding to a position at, or in the vicinity of, said minimum.
Claim 12
Independent Claim
80 words
An apparatus for producing a scanning light beam, comprising a hologram, a light beam source operable to generate a reconstruction beam, and means for moving the hologram relative to the reconstruction beam, wherein the hologram has interference fringes having a spatial variation of spatial frequency, said variation including a minimum of rate of change of spatial frequency, the apparatus being arranged to direct said reconstruction beam to points corresponding to a position at, or in the vicinity of, said minimum.
References Cited (Backward Citations)
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