[go: up one dir, main page]

WO1989006001A1 - Procede et appareil reduisant ou eliminant la tacheture dans la reproduction d'une image a partir d'un hologramme - Google Patents

Procede et appareil reduisant ou eliminant la tacheture dans la reproduction d'une image a partir d'un hologramme Download PDF

Info

Publication number
WO1989006001A1
WO1989006001A1 PCT/GB1988/001109 GB8801109W WO8906001A1 WO 1989006001 A1 WO1989006001 A1 WO 1989006001A1 GB 8801109 W GB8801109 W GB 8801109W WO 8906001 A1 WO8906001 A1 WO 8906001A1
Authority
WO
WIPO (PCT)
Prior art keywords
screen
hologram
image
speckling
reproduction
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/GB1988/001109
Other languages
English (en)
Inventor
William Nevil Heaton Johnson
Nicholas John Phillips
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Scientific Applied Research SAR PLC
Original Assignee
Scientific Applied Research SAR PLC
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Scientific Applied Research SAR PLC filed Critical Scientific Applied Research SAR PLC
Priority to KR1019890701503A priority Critical patent/KR900700933A/ko
Publication of WO1989006001A1 publication Critical patent/WO1989006001A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03H—HOLOGRAPHIC PROCESSES OR APPARATUS
    • G03H1/00—Holographic processes or apparatus using light, infrared or ultraviolet waves for obtaining holograms or for obtaining an image from them; Details peculiar thereto
    • G03H1/32—Systems for obtaining speckle elimination

Definitions

  • a method of reducing or eliminating "speckling" in repro ⁇ duction of an image by a technique involving the illumination of a hologram by light from a laser source comprising the interposition, between the laser source and the hologram, of a microlens screen,-and subjecting the screen to transverse movements' in the plane of the screen, during exposure of an imaging arrangement.
  • a laser beam 10 is shown, incident upon a transmission hologram 12 at an angle, with a resultant real image (planar in the example shown) being formed at 14, for example on a photo ⁇ sensitive layer on a planar support.
  • a light transmitting microlens screen 16 Extending trans ⁇ versely across, the beam 10, in the path of the light directed towards the hologram 12, and generally normal to the beam axis, is a light transmitting microlens screen 16.
  • the screen comprises a transparent sheet which carries an array of lenslets or microlenses, formed integrally in or on said sheet and having their principal axes substantially normal to the plane of the sheet.
  • said lenslets or microlenses are formed by a method including a photographic imagaging step, carried out upon a photopolymer.
  • the screen 16 is formed by providing on a transparent substrate a material having localised variations in refractive index so as to afford said microlenses or lenslets in the form of graded refractive index lenses.
  • the screen 16 is preferably formed by a method which utilises a compound applied to said substrate in monomeric form and which, upon selective exposure to ultraviolet light, will polymerise selectively in such a way as to afford said graded refractive index lenses and wherein the layer of monomer is initially exposed, to ultraviolet light, at each of an array of spots over the surface of the layer, to provide the desired microlenses by consequent polymerisation of the material, the material subsequently being subjected to a blanketing exposure of ultraviolet light to complete poly ⁇ merisation.
  • the material is raised to its softening temperature intermediate the selective exposure and the blanketing exposure, to enhance the refractive index variation within the regions of the microlenses.
  • Similar graded refractive index lenses may be formed in a layer of dichromated gelatin (DCG) .
  • the microlenses or lenslets may be formed by localised shaping of the surfaces of: sai sheet in the region of the or each., microlens, for example to give the microlens the form of a conventional refractive lens.
  • a sheet of the last-noted character may be formed for example, by casting, moulding or pressing an appro ⁇ priate plastics material in or upon a "master" mould or die having a surface of complementary configuration. Such a "master" mould or die may, for example, be fashioned using laser and/or holographic techniques, or by etching techniques or even mechanically.
  • such a master may be formed by coating a glass sheet with a photosensitive . resist, exposing the resist to light whilst the resist layer is in contact with a screen bearing an array of opaque dots, carrying out a developing procedure in the course of which the unexposed resist layer in the region of said- dots is removed (to assist which, after the removal of. the bulk of the unexposed resist, the resist layer may be * subjected to ion bombardment to remove residual resist from the unexposed areas and thereby- "sharpen" :the. image), and etching the resist coated surface of the glass with hydrofluoric acid for a predetermined time.
  • the layer in which the microlenses are formed may be of the order of 25 ⁇ to 50 ⁇ thick, with the diameters of the lenses and the pitch between adjacent lenses in the array, being of the same order.
  • the image formed at 14 is typically characterised by "speckling", as a consequence of which, for example features in the image which should have straight edges, may have ragged or ill-defined edges.
  • the screen 16 is, as noted above, a transparent sheet bearing a closely packed array of integral lenslets or microlenses, each microlens being a lens with positive power having its axis substantially corresponding with that of the beam 10. The power of the microlenses need only be low, as compared with the values readily obtainable using the techniques described.
  • the screen 16 is mounted by means, (not shown), arranged in operation to apply a transverse movement to the screen, such as an oscillating movement in the directions of arrows 18, for example, an oscillating or vibratory movement, of the order of a millimetre or less in amplitude.
  • a transverse movement such as an oscillating movement in the directions of arrows 18, for example, an oscillating or vibratory movement, of the order of a millimetre or less in amplitude.
  • the effect of the transverse displacement of the screen is to move the "speckle" features back and forth across the image plane 14 to an extent large in relation to the size of the speckle features, whilst leaving the portions of the image due to the hologram substantially stationary.
  • a similar technique is known using, for example, a ground glass screen.
  • this known technique there is substantial scattering of light from the laser beam in directions such as to miss the hologram 12 altogether, and this leads to a significant reduction in the effective power of the laser in such a known arrangement.
  • Such scattering can be largely eliminated by the use of the microlens screen, which can, indeed, be “tailored” to afford a desired maximum angle of deflection or effective "scattering” by arranging the focal lengths of the microlenses accordingly.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Holo Graphy (AREA)
  • Diffracting Gratings Or Hologram Optical Elements (AREA)

Abstract

Afin d'éliminer la ''tacheture'' dans la reproduction d'une image holographique utilisant une lumière laser, on a interposé entre la source de la lumière laser et l'hologramme (12), un écran (16) comprenant un réseau de microlentilles. L'écran (16) est soumis à de petits mouvements transversaux dans son propre plan, pendant l'exposition d'un agencement d'imagerie (14). Il s'ensuit une égalisation sur la période d'exposition, des effets des ''défauts'' dans le système optique utilisé dans la préparation de l'hologramme original, et ainsi une élimination de ladite tacheture dans l'image formée dans l'agencement d'imagerie (14).
PCT/GB1988/001109 1987-12-15 1988-12-13 Procede et appareil reduisant ou eliminant la tacheture dans la reproduction d'une image a partir d'un hologramme Ceased WO1989006001A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
KR1019890701503A KR900700933A (ko) 1987-12-15 1988-12-13 홀로그램에 영상을 재현시킴에 있어서 작은 반점의 찍힘을 감소시키거나 제거시키는 방법 및 그 장치

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB8729212 1987-12-15
GB878729212A GB8729212D0 (en) 1987-12-15 1987-12-15 Method of & apparatus for reducing/eliminating speckling in reproduction of image from hologram

Publications (1)

Publication Number Publication Date
WO1989006001A1 true WO1989006001A1 (fr) 1989-06-29

Family

ID=10628507

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/GB1988/001109 Ceased WO1989006001A1 (fr) 1987-12-15 1988-12-13 Procede et appareil reduisant ou eliminant la tacheture dans la reproduction d'une image a partir d'un hologramme

Country Status (3)

Country Link
KR (1) KR900700933A (fr)
GB (1) GB8729212D0 (fr)
WO (1) WO1989006001A1 (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19704741A1 (de) * 1997-02-13 1998-08-20 Daimler Benz Ag Holografischer Bildschirm mit integrierter Speckleunterdrückung
EP1260850A1 (fr) * 2001-05-25 2002-11-27 EADS Deutschland Gmbh Méthode et dispositif pour éliminer des perturbations stationnaires d'images pendant la projection d'images avec la lumière cohérente en temps ou dans l'espace et système de projection d'images

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR101227474B1 (ko) * 2004-12-31 2013-01-30 엘지전자 주식회사 레이저 반점 감소 장치 및 이를 이용한 광학계

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3490827A (en) * 1967-10-19 1970-01-20 American Optical Corp Method and apparatus for speckle reduction in the reconstruction of holographic images
US3850515A (en) * 1970-07-16 1974-11-26 Texas Instruments Inc Coherent light array for use in image projection systems
GB1410056A (en) * 1972-09-13 1975-10-15 Thomson Csf Systems for constructing small fresnel holograms

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3490827A (en) * 1967-10-19 1970-01-20 American Optical Corp Method and apparatus for speckle reduction in the reconstruction of holographic images
US3850515A (en) * 1970-07-16 1974-11-26 Texas Instruments Inc Coherent light array for use in image projection systems
GB1410056A (en) * 1972-09-13 1975-10-15 Thomson Csf Systems for constructing small fresnel holograms

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
Journal of the Optical Society of America, volume 61, no. 7, July 1971, Optical Society of America, S. Lowenthal et al.: "Speckle removal by a slowly moving diffuser associated with a motionless diffuser", pages 847-851 *
Journal of the Optical Society of America, volume 63, no. 9, September 1973, C.N. Kurtz et al.: "Design and synthesis of random phase diffusers", pages 1080-1092 *

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6268941B1 (en) 1997-02-07 2001-07-31 Daimlerchrysler Ag Holographic display screen with integrated speckle suppression
DE19704741A1 (de) * 1997-02-13 1998-08-20 Daimler Benz Ag Holografischer Bildschirm mit integrierter Speckleunterdrückung
EP1260850A1 (fr) * 2001-05-25 2002-11-27 EADS Deutschland Gmbh Méthode et dispositif pour éliminer des perturbations stationnaires d'images pendant la projection d'images avec la lumière cohérente en temps ou dans l'espace et système de projection d'images

Also Published As

Publication number Publication date
GB8729212D0 (en) 1988-01-27
KR900700933A (ko) 1990-08-17

Similar Documents

Publication Publication Date Title
US5442482A (en) Microlens screens, photopolymerisable materials and artifacts utilising the same
US3580657A (en) Blazed surface hologram
US4523807A (en) Method for making a member having microstructure elements arranged thereon
US4132479A (en) Pattern transfer optical system
EP0415230B1 (fr) Procédé pour fabriquer des hologrammes évanescents graduellement sur les bords
DK167782B1 (da) Bagprojektionsskaerm og fremgangsmaade til fremstilling af samme
KR101060323B1 (ko) 네가티브 포토레지스트를 이용하여 기판을 통과하는미세구조의 마스터링을 위한 시스템과 그 방법 및 상기방법으로 제조한 미세구조 마스터
KR101192624B1 (ko) 외부층들 사이에 개재된 감광조사층을 이미지 전사함으로써 미세구조를 제조하는 시스템 및 방법과 이를 이용하여 제조된 미세구조
EP0251681A2 (fr) Fabrication de circuits intégrés utilisant des techniques holographiques
US4421398A (en) Focussing plate
US3669673A (en) Recording of a continuous tone focused image on a diffraction grating
US4244633A (en) Multicolor hologram and method for forming same
WO1994004948A1 (fr) Appareil pour creer des images autostereoscopiques et dynamiques et procede pour sa fabrication
KR100870800B1 (ko) 고정밀도 구경을 갖는 자기 정합 구경 마스크
US3630598A (en) Optical demodulation filter
US3630593A (en) Holographically produced image arrays for photolithography
EP4123347A1 (fr) Procédé de réplication d'un élément optique holographique de grande surface, et élément optique holographique de grande surface répliqué par celui-ci
EP0671638B1 (fr) Méthode de fabrication d'un diffuseur et diffuseur
JPH05228946A (ja) 光学部品の製造法および光学部品複製用母型
T O’Neill et al. Refractive elements produced in photopolymer layers
US4372649A (en) Extended area diffractive subtractive color filters
WO1989006001A1 (fr) Procede et appareil reduisant ou eliminant la tacheture dans la reproduction d'une image a partir d'un hologramme
EP0396538A1 (fr) Procede de fabrication d'une fine lentille
US5278008A (en) Diffraction efficiency control in holographic elements
EP0135047B1 (fr) Procédé de fabrication d'une lentille holographique

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): JP KR US

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): AT BE CH DE FR GB IT LU NL SE