EP1228400A1 - Ecran de diffusion ou de projection - Google Patents

Ecran de diffusion ou de projection

Info

Publication number
EP1228400A1
EP1228400A1 EP00973033A EP00973033A EP1228400A1 EP 1228400 A1 EP1228400 A1 EP 1228400A1 EP 00973033 A EP00973033 A EP 00973033A EP 00973033 A EP00973033 A EP 00973033A EP 1228400 A1 EP1228400 A1 EP 1228400A1
Authority
EP
European Patent Office
Prior art keywords
light
grooves
workpiece
sheet
laser
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.)
Withdrawn
Application number
EP00973033A
Other languages
German (de)
English (en)
Inventor
Robin James Thomas Clabburn
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.)
Microsharp Corp Ltd
Original Assignee
Microsharp Corp Ltd
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 Microsharp Corp Ltd filed Critical Microsharp Corp Ltd
Publication of EP1228400A1 publication Critical patent/EP1228400A1/fr
Withdrawn legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
    • G03B21/00—Projectors or projection-type viewers; Accessories therefor
    • G03B21/54—Accessories
    • G03B21/56—Projection screens
    • G03B21/60—Projection screens characterised by the nature of the surface
    • G03B21/62—Translucent screens
    • G03B21/625—Lenticular translucent screens
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
    • G03B21/00—Projectors or projection-type viewers; Accessories therefor
    • G03B21/54—Accessories
    • G03B21/56—Projection screens
    • G03B21/60—Projection screens characterised by the nature of the surface
    • G03B21/602—Lenticular screens

Definitions

  • Such a diffuser is of utility, for example, in projection applications, where the off-axis effect allows observers viewing a projection screen to perceive a projected image at maximum brightness without the observers themselves being in the way of the light projected towards the screen or, for example, as a means of allowing an LCD display to be viewed in ambient light, in such a way that the observer's head may conveniently be located in a position, in relation to the screen, in which it does not interfere with light incident on the screen at the angle appropriate for optimum viewing of the screen by the observer.
  • Other possible applications of such a diffuser will be evident to those skilled in the art.
  • the material destined to form the diffusion screen may be directly acted on by the laser beam, but in practice the laser scanning technique will normally be used to form a master, from which, by known electrotyping or other techniques, an embossing tool or mould having a corresponding surface configuration may be produced, with the diffusing screen being produced by impressing plastics material, in a flowable condition, using the mould or embossing tool thus produced.
  • the master created by laser machining a plastics material may have silver deposited by vacuum deposition on its machined surface and a layer of nickel may thereafter be applied by an electroplating technique onto the silver to form a nickel shim or mould to be used to replicate the original shape of the plastics master. In the replication process, a u.v.
  • FIGURE 3 is a diagrammatic perspective view illustrating a laser machining process forming a stage in the manufacture of the screen of Figures 1 and 2
  • FIGURE 4 is a diagrammatic perspective view to a larger scale than Figure 3 showing laser apparatus forming part of that illustrated in Figure 3
  • the pitch between the grooves 5, i.e. between the ramps of the Fresnel profile illustrated in Figures 1 and 2 may be of the order of 40 microns, whereas the smaller transverse grooves 7 may be around 5 microns wide, (i.e. may be arranged at approximately 5 microns pitch).
  • the structure illustrated in Figure 1 may be produced by laser machining of a workpiece in the form of a sheet of, for example, plastics, by a laser, in a process illustrated highly schematically in Figures 3 and 4.
  • a plastics workpiece 20 in the form of a Mylar (polyester) sheet may be machined using a pulsed excimer laser pulsed at a pulse repetition rate of 20 to 120 Hz.
  • the output power of such a laser may be 0.2 - 1.2 J/cm 2 .
  • the laser apparatus 26 is illustrated in Figure 4 as comprising a laser proper, represented at 28, directing a laser beam 30 through a first optical element or system 31 adapted to expand or diverge the beam (this expansion of the beam serves, inter alia, to avoid damage to the mask), then through an apertured plate 32 the image of the aperture in which is focused by a lens or optical system 34 onto the workpiece 20 to form an illuminated patch on the workpiece which is of the same configuration as the aperture in the plate 32.
  • the grooved or saw-tooth profiled surface of the diffuser produced as described above may be provided, as illustrated in Figure 9, with a transparent coating 50 intimately contacting the grooved surface of the substrate, referenced 20a, produced as described above and providing a flat optically smooth exposed surface 52 which thus forms one of two opposite flat surfaces of the resulting product.
  • a transparent coating 50 intimately contacting the grooved surface of the substrate, referenced 20a, produced as described above and providing a flat optically smooth exposed surface 52 which thus forms one of two opposite flat surfaces of the resulting product.
  • the diffuser is transmissive rather than reflective
  • such layer 50 is selected to have a refractive index significantly different from that of substrate 20a.
  • the grooved surface of substrate 20a is arranged to be a light-reflective diffuser
  • the layer 50 may be, but need not be, of a different refractive index from the material of the substrate 20a (if the substrate 20a is indeed light-transmitting).
  • the arrangement may be similar to that disclosed in GB-23149
  • the first, A comprised an array of parallel grooves 5 generally of the form shown in Figure 2 defining a corresponding array of parallel prisms with a prism angle of 10° and a prism pitch of 50 ⁇ m;
  • the second, B comprised a similar arrangement of parallel grooves and prisms, but in which successive prisms had different prism angles such that the array comprised a repeating sequence of 3 prisms with prism angles of 8°, 12° and 16° each with a pitch of 30 ⁇ m, the sequence repeating every 90 ⁇ m.
  • the light scattering of the microgroove substructure was examined under a microscope and the diffusion of the substructure measured separately.
  • the substructure of -A- (single prism) was as represented in Figure 1.
  • the grooves 7 had a width of about 3 ⁇ m.
  • the scattering (diffusion) as measured using a goniometer was about 15° (full width, half maximum intensity).

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Overhead Projectors And Projection Screens (AREA)
  • Optical Elements Other Than Lenses (AREA)
  • Transforming Electric Information Into Light Information (AREA)

Abstract

La présente invention concerne un écran diffuseur comprenant une feuille (20) de matériau dont une surface présente une structure cannelée comprenant une série de premières nervures ou rainures parallèles (5) de profil angulaire ou lenticulaire. La surface principale de chaque nervure ou rainure précitée (5) possède une fine structure ou texture composée d'un réseau de nervures ou rainures généralement parallèles (7), sensiblement plus étroites que les premières nervures ou rainures (5) et s'étendant perpendiculairement à la longueur des premières nervures ou rainures (5). L'écran peut être fabriqué par usinage laser d'une pièce en mode ligne par ligne à l'aide d'un laser pulsé.
EP00973033A 1999-11-05 2000-11-02 Ecran de diffusion ou de projection Withdrawn EP1228400A1 (fr)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
GBGB9926315.4A GB9926315D0 (en) 1999-11-05 1999-11-05 Diffusion or projection screen
GB9926315 1999-11-05
PCT/GB2000/004221 WO2001033299A1 (fr) 1999-11-05 2000-11-02 Ecran de diffusion ou de projection

Publications (1)

Publication Number Publication Date
EP1228400A1 true EP1228400A1 (fr) 2002-08-07

Family

ID=10864080

Family Applications (1)

Application Number Title Priority Date Filing Date
EP00973033A Withdrawn EP1228400A1 (fr) 1999-11-05 2000-11-02 Ecran de diffusion ou de projection

Country Status (5)

Country Link
EP (1) EP1228400A1 (fr)
JP (1) JP2003513338A (fr)
AU (1) AU1158901A (fr)
GB (1) GB9926315D0 (fr)
WO (1) WO2001033299A1 (fr)

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100487105B1 (ko) * 2004-06-04 2005-05-04 주식회사 엘지에스 광학필름
DE102005040147A1 (de) * 2005-08-25 2007-03-01 Leopold Kostal Gmbh & Co. Kg Sonnensensor für ein Kraftfahrzeug
JP4918768B2 (ja) * 2005-09-22 2012-04-18 凸版印刷株式会社 光学スクリーンとそれを用いたプロジェクションスクリーンおよびその光学スクリーンの製造方法
JP5040187B2 (ja) * 2005-09-28 2012-10-03 ソニー株式会社 賦型の製造方法およびレンズシートの製造方法
CN104460213A (zh) * 2014-12-26 2015-03-25 成都宽显科技有限责任公司 投影屏幕及投影显示系统
CN112219163B (zh) * 2018-05-25 2022-09-13 Ａｇｃ株式会社 影像投影结构体及其制造方法、以及影像显示系统

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3782805A (en) * 1972-11-30 1974-01-01 Qantix Corp Front projection screen made from a transparent material
US3966301A (en) * 1974-12-19 1976-06-29 Qantix Corporation Transparent screen having intermittent portions for reducing reflection from ambient light
US4040717A (en) * 1975-11-26 1977-08-09 Cinque Alphonse P Projection screen for optical images
AU7881291A (en) * 1990-05-21 1991-12-10 Sar Realisations Limited Improvements in or relating to microlens screens, photopolymerisable materials and artifacts utilising the same
US5448401A (en) * 1992-12-25 1995-09-05 Sony Corporation Screen of projection display
EP0801767B1 (fr) * 1993-06-15 1999-08-25 Nashua Corporation Procédé pour fabriquer un masque randomisé pour écran diffuseur

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO0133299A1 *

Also Published As

Publication number Publication date
WO2001033299A1 (fr) 2001-05-10
AU1158901A (en) 2001-05-14
GB9926315D0 (en) 2000-01-12
JP2003513338A (ja) 2003-04-08

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