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EP1570303A1 - High index of refraction coated light management films - Google Patents

High index of refraction coated light management films

Info

Publication number
EP1570303A1
EP1570303A1 EP03789876A EP03789876A EP1570303A1 EP 1570303 A1 EP1570303 A1 EP 1570303A1 EP 03789876 A EP03789876 A EP 03789876A EP 03789876 A EP03789876 A EP 03789876A EP 1570303 A1 EP1570303 A1 EP 1570303A1
Authority
EP
European Patent Office
Prior art keywords
film
organic light
light management
transparent inorganic
inorganic film
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Withdrawn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
EP03789876A
Other languages
German (de)
French (fr)
Inventor
Bret Chisholm
Eugene Olczak
Marc Schaepkens
Dennis Coyle
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.)
SABIC Global Technologies BV
Original Assignee
General Electric Co
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
Priority claimed from US10/065,957 external-priority patent/US6811274B2/en
Application filed by General Electric Co filed Critical General Electric Co
Publication of EP1570303A1 publication Critical patent/EP1570303A1/en
Withdrawn legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
    • G02B6/0011—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
    • G02B6/0033—Means for improving the coupling-out of light from the light guide
    • G02B6/005—Means for improving the coupling-out of light from the light guide provided by one optical element, or plurality thereof, placed on the light output side of the light guide
    • G02B6/0053—Prismatic sheet or layer; Brightness enhancement element, sheet or layer
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B1/00—Optical elements characterised by the material of which they are made; Optical coatings for optical elements
    • G02B1/10—Optical coatings produced by application to, or surface treatment of, optical elements
    • G02B1/11—Anti-reflection coatings
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B1/00—Optical elements characterised by the material of which they are made; Optical coatings for optical elements
    • G02B1/10—Optical coatings produced by application to, or surface treatment of, optical elements
    • G02B1/11—Anti-reflection coatings
    • G02B1/111—Anti-reflection coatings using layers comprising organic materials
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/20—Filters
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/20—Filters
    • G02B5/28—Interference filters
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/20—Filters
    • G02B5/28—Interference filters
    • G02B5/285—Interference filters comprising deposited thin solid films
    • G02B5/287—Interference filters comprising deposited thin solid films comprising at least one layer of organic material
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/30—Polarising elements
    • G02B5/3025—Polarisers, i.e. arrangements capable of producing a definite output polarisation state from an unpolarised input state
    • G02B5/3033—Polarisers, i.e. arrangements capable of producing a definite output polarisation state from an unpolarised input state in the form of a thin sheet or foil, e.g. Polaroid
    • G02B5/3041—Polarisers, i.e. arrangements capable of producing a definite output polarisation state from an unpolarised input state in the form of a thin sheet or foil, e.g. Polaroid comprising multiple thin layers, e.g. multilayer stacks
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333—Constructional arrangements; Manufacturing methods
    • G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333—Constructional arrangements; Manufacturing methods
    • G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
    • G02F1/1336—Illuminating devices
    • G02F1/13362—Illuminating devices providing polarized light, e.g. by converting a polarisation component into another one

Definitions

  • This invention is related generally to high refractive index light management films, and devices incorporating such films, and methods for forming such films.
  • Light management films are known to be used in optical device applications such as, for example, for liquid crystal displays (LCDs).
  • LCDs may include, for example, one or more quarter wave plates, brightness enhancing films, retardation foils, diffuser films, color filters, high pass filters, band pass filters, and low pass filters.
  • These light management films are typically formed of organic materials with a refractive index typically less than 1.7.
  • the light management films may include a number of raised features.
  • an optical structure comprising: a light source; an organic light management film having an index of refraction of less than 1.7 disposed above the light source; and a transparent inorganic film having an index of refraction of greater than 1.7 disposed adjacent the organic light management film.
  • an optical device comprising: a backlight comprising a source of light; a modulation array comprising a liquid crystal material disposed above the back light; an organic light management film having an index of refraction of less than 1.7 disposed above the backlight; and a transparent inorganic film having an index of refraction of greater than 1.7 disposed adjacent the organic light management film.
  • a method of forming an optical structure comprising: providing an organic light management film having an index of refraction of less than 1.7; depositing under vacuum a transparent inorganic film having an index of refraction of greater than 1.7 on the organic light management film; and disposing the organic light management film into an optical structure which includes a light source before or after the step of depositing under vacuum.
  • Figure 1 is a side view of an optical structure according to a preferred embodiment of the invention.
  • Figure 2 is a side view of an optical structure according to another preferred embodiment of the invention.
  • Figure 3 is a side view of an optical structure according to another preferred embodiment of the invention.
  • Figure 4 is a schematic illustrating the optical effect of the high index inorganic film.
  • Figure 5 is a schematic illustrating the optical effect of the high index inorganic film according to a preferred embodiment of the invention.
  • Figure 6 is a side view of an optical structure acting as an interference filter according to a preferred embodiment of the invention.
  • Figure 7 is a side view of an optical structure acting as an interference filter according to another preferred embodiment of the invention.
  • Figure 8 is a side view of an optical structure acting as an interference filter according to another preferred embodiment of the invention.
  • Figure 9 is a graph illustrating the % reflectance as a function of wavelength for the optical structure of Figure 6.
  • Figure 10 is a graph illustrating the % reflectance as a function of wavelength for the optical structure of Figure 7.
  • Figure 11 is a graph illustrating the % fransmittance as a function of wavelength for the optical structure of Figure 8.
  • Figure 12 is a side view of an optical device according to another preferred embodiment of the invention.
  • Figure 13 is a side view of an optical structure according to another preferred embodiment of the invention.
  • an inorganic high index of refraction material i.e., a material with an index of refraction greater than 1.7, preferably greater than 2
  • adjacent an organic light management film with an index of refraction less than 1.7, preferably less than 1.5 can enhance the optical effects achieved with the organic light management film.
  • the organic light management film with the adjacent high index inorganic film can manipulate the directionality of the light toward a viewer, or select certain polarizations over others.
  • the high index film by further affecting the directionality of light, may improve the viewing angle for a viewer of and LCD and the contrast of an LCD display.
  • a high index film on a low index light management film enhances the specific performance of the coated light management film.
  • FIG. 1 is a schematic illustration of an optical structure according to an embodiment of the invention.
  • the optical structure 10 includes a light source 14 in a substrate 12, with an organic light management film 16 disposed above the light source 14.
  • the organic light management film 16 may be a quarter wave plate, brightness enhancing film, retardation foil, diffuser film, color filter, high pass filter, band pass filter, or low pass filter, for example.
  • the organic light management film 16 is a color filter, it may be a color filter array with individual red, blue and green pixel sized filters. If it is a filter, the filter might be used as a color selective transflector, a neutral density filter, an IR blocking filter or a UN blocking filter, for example.
  • the optical structure 10 also includes a high index (i.e., an index of refraction greater than 1.7) transparent inorganic film 18 adjacent the organic light management film 16.
  • the organic light management film 16 and the transparent inorganic film 18 may also be arranges as a number of alternating layers, i.e., a plurality of films 18 alternating with a plurality of films 16.
  • the organic light management film 16 may have a plurality of raised features 20, such as prismatic features, for example.
  • the transparent inorganic film 18 may be disposed conformally on the organic light management film 16 with the plurality of raised features 20.
  • the organic light management film 16 comprises two sublayers, a substrate layer 16A and an overlayer 16B. While the substrate layer 16A does not have raised features, the overlayer 16 does have the raised features 20.
  • Figure 2 illustrates another embodiment where the organic light management film 16 includes only a substrate layer 16A, and the substrate layer 16A includes a plurality of raised features 20.
  • Figure 3 illustrates another embodiment where the organic light management film 16 includes only a substrate layer 16A.
  • the substrate layer 16A does not include raised features, but the transparent inorganic film 18 disposed on the substrate layer 16A includes a plurality of raised features 20.
  • the structure 10 of the embodiments of Figures 1, 2 or 3 may also include an interlayer 15 disposed between the substrate 12 and the organic light management film 16.
  • the interlayer 15 may be a thin metal layer, for example.
  • the interlayer may be disposed between the organic light management film 16 and the transparent inorganic film 18.
  • Figure 4 illustrates the effect of the inorganic film 18 on the light emitted from the light source 10.
  • the organic light management film 16 and the inorganic film 18 have indices of refraction of m and n 2 , respectively, with ni ⁇ 1.7 and n 2 > 1.7.
  • a light ray 30 travels in the organic light management film 16 at an angle ⁇ i with respect to the normal 34 to the bottom surface 36 of the organic light management film 16.
  • the light ray 30 is refracted at the interface of the organic light management film 16 and the inorganic film 18 due to the different indices of refraction for these materials according to known optical principles, and makes an angle ⁇ 2 with respect to the normal to the surface 38 of the inorganic film 18.
  • Figure 5 illustrates the effect of the inorganic film 18 on the light emitted from the light source 10 in the case where the organic light management film 16 includes a number of raised features 20.
  • Figure 5 has the same structure as Figure 4 except for the raised features 20.
  • the raised features 20 are prismatic structures having prismatic surfaces, and the inorganic film 18 is conformal to the organic light management film 16.
  • the light ray 30 in Figure 5 travels in the organic light management film 16 at an angle ⁇ with respect to the normal 34 to the bottom surface 36 of the organic light management film 16.
  • the light ray 30 is refracted at interface of the organic light management film 16 and the inorganic film 18 due to the different indices of refraction for these materials according to known optical principles, h Figure 5, the light ray 30 passes from the inorganic film 18 to air or vacuum with an index of refraction of about 1.0. Because the top surface 39 of the organic light management film 16 is not parallel to that of the bottom surface 36, and because the inorganic film 18 is conformal to the organic light management film 16, in Figure 5, the light ray 30 may leave the inorganic film 18 in a direction which is normal to the bottom surface organic light management film 16 at an oblique angle, may leave the inorganic film 18 at an angle normal to bottom surface 36 of the organic light management film 16.
  • Figure 5 illustrates an example of how oblique light rays may be redirected using the high index inorganic film 18.
  • the inorganic film 18 not only affects the directionality of light leaving the film 18, but also can selectively affect the polarization of the light, as disclosed in U.S. application serial no. 10/065,957, filed on December 4, 2002, entitled "POLARIZATION SENSITIVE OPTICAL SUBSTRATE", which is hereby incorporated by reference in its entirety.
  • Figures 6-8 illustrate embodiment of the invention where the inorganic films 18 and the organic light management films 16 alternate in optical structures, wherein the optical structures act as interference filters.
  • An interference filter as is known in the art, is a filter that controls the spectral composition of transmitted (and reflected) light energy in part through interference of light reflected at the layer interfaces of the films making up the filter.
  • Figure 6 illustrates an embodiment with two inorganic films 18 and two organic light management films 16 arranged in alternate fashion.
  • the optical structure 70 of Figure 6 is arranged to operate as a narrow antireflection filter.
  • Figure 9 is a graph showing the % reflectance as a function of wavelength for normal light incidence on the optical structure 70 of Figure 6.
  • Figure 9 shows the % reflectance specifically for the case where the index of refraction of the inorganic films 18 and the organic light management films 16 is 2.5 and 1.45, respectively, and where the layer thicknesses from the top to the bottom layer in Figure 6 is 17.35 rrm, 35.32 nm, 132.66 nm and 94.50 nm, respectively.
  • Figure 7 illustrates an embodiment with a single inorganic film 18 and a single organic light management film 16 arranged as shown.
  • the optical structure 80 of Figure 7 is arranged to operate as a wide antireflection filter.
  • Figure 10 is a graph showing the % reflectance as a function of wavelength for normal light incidence on the optical structure 80 of Figure 7.
  • Figure 10 shows the % reflectance specifically for the case where the index of refraction of the inorganic film 18 and the organic light management film 16 is 2.05 and 1.38, respectively, and where the layer thicknesses of the inorganic film 18 and the organic light management film 16 in Figure 7 is 134.15 nm, 99.64 nm, respectively.
  • Figure 8 illustrates an embodiment with several inorganic films 18 and several organic light management films 16 arranged in alternate fashion.
  • the optical structure 90 of Figure 8 is arranged to operate as a wide band reflection filter.
  • Figure 11 is a graph showing the % fransmittance as a function of wavelength for normal light incidence on the optical structure 90 of Figure 9.
  • Figure 11 shows the % reflectance specifically for the case where the index of refraction of the inorganic films 18 and the organic light management films 16 is 2.35 and 1.45, respectively, and where the layer thicknesses from the top to the bottom layer in Figure 8 ranges between about 20 m l and about 225 nm, respectively.
  • the total number of inorganic films 18 and the organic light management films 16 together is 59 for the graph of Figure 11. Of course in practice the total number of layers will vary depending upon the application.
  • Figure 12 is a schematic of an optical device 40 according to an embodiment of the present invention.
  • the optical device 40 includes a modulation array 42 comprising a liquid crystal material.
  • the modulation array selectively allows light to pass through a pixel of the array as is known in the art.
  • the optical device 40 may be a liquid crystal display (LCD), for example.
  • the optical device 40 may include elements of the optical structure described above with respect to Figure 1.
  • the optical device 40 includes a substrate 12, which may be a backlight, for example, including a light source 14. Disposed between the modulation array 42 and the substrate 12, or on the opposite side of the modulation array 42 from the substrate 12 are one or more organic light management films 16 (with an index of refraction less than 1.7) with a corresponding adjacent transparent inorganic film 18 (with an index of refraction greater than 1.7).
  • the organic light management film 16 may be one or more of a quarter wave plate, brightness enhancing film, retardation foil, diffuser film, color filter, high pass filter, band pass filter, low pass filter, for example. If the organic light management film 16 is a color filter, it may be a color filter array with individual red, blue and green pixel sized filters, for example. If a filter, the filter might be used as a color selective transflector.
  • the organic light management film 16 and the transparent inorganic film 18 may also be disposed alternately in a number of layers.
  • the organic light management films 16 may have a plurality of raised features 20, such as prismatic features, for example.
  • the transparent inorganic films 18 may be disposed conformally on their respective organic light management film 16 with the plurality of raised features 20.
  • the organic light management film 16 may comprise a substrate layer and a overlayer as in the embodiment of Figure 1, or just a substrate layer as in the embodiments of Figures 2 and 3.
  • the organic light management film 16 and the transparent inorganic film 18 may also be arranged alternately as in the embodiments of Figures 6-8.
  • the transparent inorganic film 18 in the above embodiments of may be formed of inorganic materials such as, for example, metal oxides, such as titanium oxide and zinc oxide, or nitrides, such as silicon nitride, or oxynitrides, such as silicon oxynitride.
  • the transparent inorganic film 18 may also be formed of ceramic compounds, such as boron carbon nitride. Thin transparent metal films may also be used for the transparent inorganic film 18.
  • the transparent inorganic film 18 may also be formed of transparent conducting oxide coatings such as Indium Tin Oxide, Indium Oxide, Tin Oxide, or Cadmium Tin Oxide.
  • the material for the organic light management film 16 will depend upon the application, and may be, for example, an organic polymer such as polycarbonate.
  • Method of forming transparent inorganic film will depend upon the application, and may be, for example, an organic polymer such as polycarbonate.
  • the transparent inorganic film 18 is preferably formed by depositing under vacuum in an enclosed deposition chamber. Because the film 18 is inorganic, there are a variety of deposition methods under vacuum in an enclosed deposition chamber which may be used. Suitable techniques for deposition of the transparent inorganic film 18 include physical vapor deposition techniques. These physical vapor deposition techniques include, for example, electron beam evaporation, thermal evaporation, and sputtering. Suitable techniques for deposition of the transparent inorganic film 18 also include chemical vapor deposition techniques. These chemical vapor deposition techniques include, for example, chemical vapor deposition, plasma assisted chemical vapor deposition, expanding thermal plasma deposition and atmospheric plasma chemical vapor deposition.
  • the raised features 20 either on the organic light management film 16, or on the transparent inorganic film 18, can be formed by conventional photolithography techniques, such as be depositing photoresist, exposing through a photomask, developing the photoresist to pattern it, followed by etching through the patterned photoresist.
  • the transparent inorganic film 18 may be deposited in a conformal fashion over existing raised features 20 in the organic light management film 16. However, for specific applications directional deposition either from normal angle or oblique angle relative to the substrate 12 maybe preferred.
  • the organic light management film 16 may be disposed into an optical structure which includes a light source, such as onto a backlight, for example.
  • Figure 13 illustrates an optical structure 50 where the raised features 20 are prismatic features, and only those portions of the features with a surface perpendicular to the direction from which the material is deposited are coated with a first transparent inorganic film 18 A.
  • the organic light management film 16 will be effected by the first transparent inorganic film 18A only for those portions covered by the first transparent inorganic film 18 A.
  • the organic light management film 16 may comprise a substrate layer and an overlayer as in the embodiment of Figure 1, or just a substrate layer as in the embodiment of Figure 2.
  • those portions of the organic light management film 16 not covered with the first transparent inorganic film 18 A may be covered with a second transparent inorganic film 18B.
  • the second fransparent inorganic film 18B may be made of the same or a different material from the first transparent inorganic film 18 A.
  • the second transparent inorganic film 18B is made of a different material from the first transparent inorganic film 18 A with a different index of refraction.
  • the second transparent inorganic film 18B may be formed by directional deposition after the first transparent inorganic film 18A.
  • the orientation of the substrate is changed relative to the direction from which the material is deposited so that a different surface is perpendicular to the direction from which the material is deposited to form the second transparent inorganic film 18B.
  • the thickness of the organic light management films 16 and the transparent inorganic films 18 in the above embodiments will depend on the application but are typically between 10 nm and 10,000 nm.
  • the thickness of the optical structures in the above embodiments will also depend on the application but are typically between 100 nm and 5 cm.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Nonlinear Science (AREA)
  • Mathematical Physics (AREA)
  • Chemical & Material Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Polarising Elements (AREA)
  • Physical Vapour Deposition (AREA)
  • Surface Treatment Of Optical Elements (AREA)
  • Planar Illumination Modules (AREA)

Abstract

There is provided an optical structure. The optical structure includes a light source (14). The optical structure also includes an organic light management film (16) having an index of refraction of less than 1.7 disposed above the light source, and a transparent inorganic film (18) having an index of refraction of greater than 1.7 disposed adjacent the organic light management film (16). A optical device is also provided including the organic light management film (16) and the transparent inorganic film (18). A method of forming the optical structure is also provided. The method includes depositing the transparent inorganic film (18) under vacuum.

Description

HIGH INDEX OF REFRACTION COATED LIGHT MANAGEMENT FILMS
RELATED INVENTIONS
This application is a continuation-in-part application of U.S. application serial no. 10/065,957, filed on December 4, 2002, entitled "POLARIZATION SENSITIVE OPTICAL SUBSTRATE", which is hereby incorporated by reference in its entirety.
FIELD OF THE INVENTION
This invention is related generally to high refractive index light management films, and devices incorporating such films, and methods for forming such films.
BACKGROUND OF THE INVENTION
Light management films are known to be used in optical device applications such as, for example, for liquid crystal displays (LCDs). Light management films in LCDs may include, for example, one or more quarter wave plates, brightness enhancing films, retardation foils, diffuser films, color filters, high pass filters, band pass filters, and low pass filters. These light management films are typically formed of organic materials with a refractive index typically less than 1.7. Depending on the application, the light management films may include a number of raised features.
SUMMARY OF THE INVENTION
In accordance with one aspect of the present invention, there is provided an optical structure comprising: a light source; an organic light management film having an index of refraction of less than 1.7 disposed above the light source; and a transparent inorganic film having an index of refraction of greater than 1.7 disposed adjacent the organic light management film.
In accordance with another aspect of the present invention, there is provided an optical device comprising: a backlight comprising a source of light; a modulation array comprising a liquid crystal material disposed above the back light; an organic light management film having an index of refraction of less than 1.7 disposed above the backlight; and a transparent inorganic film having an index of refraction of greater than 1.7 disposed adjacent the organic light management film.
In accordance with another aspect of the present invention, there is provided a method of forming an optical structure comprising: providing an organic light management film having an index of refraction of less than 1.7; depositing under vacuum a transparent inorganic film having an index of refraction of greater than 1.7 on the organic light management film; and disposing the organic light management film into an optical structure which includes a light source before or after the step of depositing under vacuum.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a side view of an optical structure according to a preferred embodiment of the invention.
Figure 2 is a side view of an optical structure according to another preferred embodiment of the invention.
Figure 3 is a side view of an optical structure according to another preferred embodiment of the invention.
Figure 4 is a schematic illustrating the optical effect of the high index inorganic film.
Figure 5 is a schematic illustrating the optical effect of the high index inorganic film according to a preferred embodiment of the invention.
Figure 6 is a side view of an optical structure acting as an interference filter according to a preferred embodiment of the invention.
Figure 7 is a side view of an optical structure acting as an interference filter according to another preferred embodiment of the invention.
Figure 8 is a side view of an optical structure acting as an interference filter according to another preferred embodiment of the invention. Figure 9 is a graph illustrating the % reflectance as a function of wavelength for the optical structure of Figure 6.
Figure 10 is a graph illustrating the % reflectance as a function of wavelength for the optical structure of Figure 7.
Figure 11 is a graph illustrating the % fransmittance as a function of wavelength for the optical structure of Figure 8.
Figure 12 is a side view of an optical device according to another preferred embodiment of the invention.
Figure 13 is a side view of an optical structure according to another preferred embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference will now be made in detail to presently preferred embodiments of the present invention. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.
The present inventors have realized that applying an inorganic high index of refraction material, i.e., a material with an index of refraction greater than 1.7, preferably greater than 2, adjacent an organic light management film with an index of refraction less than 1.7, preferably less than 1.5, can enhance the optical effects achieved with the organic light management film. The organic light management film with the adjacent high index inorganic film can manipulate the directionality of the light toward a viewer, or select certain polarizations over others. The high index film, by further affecting the directionality of light, may improve the viewing angle for a viewer of and LCD and the contrast of an LCD display. Thus, a high index film on a low index light management film enhances the specific performance of the coated light management film. In particular the high index film may be used in an LCD to increase efficiency or enhance wavelength or polarization selectivity. Figure 1 is a schematic illustration of an optical structure according to an embodiment of the invention. The optical structure 10 includes a light source 14 in a substrate 12, with an organic light management film 16 disposed above the light source 14. The organic light management film 16 may be a quarter wave plate, brightness enhancing film, retardation foil, diffuser film, color filter, high pass filter, band pass filter, or low pass filter, for example. If the organic light management film 16 is a color filter, it may be a color filter array with individual red, blue and green pixel sized filters. If it is a filter, the filter might be used as a color selective transflector, a neutral density filter, an IR blocking filter or a UN blocking filter, for example.
The optical structure 10 also includes a high index (i.e., an index of refraction greater than 1.7) transparent inorganic film 18 adjacent the organic light management film 16. The organic light management film 16 and the transparent inorganic film 18 may also be arranges as a number of alternating layers, i.e., a plurality of films 18 alternating with a plurality of films 16. The organic light management film 16 may have a plurality of raised features 20, such as prismatic features, for example. The transparent inorganic film 18 may be disposed conformally on the organic light management film 16 with the plurality of raised features 20.
In the embodiment of Figure 1, the organic light management film 16 comprises two sublayers, a substrate layer 16A and an overlayer 16B. While the substrate layer 16A does not have raised features, the overlayer 16 does have the raised features 20.
Figure 2 illustrates another embodiment where the organic light management film 16 includes only a substrate layer 16A, and the substrate layer 16A includes a plurality of raised features 20.
Figure 3 illustrates another embodiment where the organic light management film 16 includes only a substrate layer 16A. In this embodiment the substrate layer 16A does not include raised features, but the transparent inorganic film 18 disposed on the substrate layer 16A includes a plurality of raised features 20.
The structure 10 of the embodiments of Figures 1, 2 or 3 may also include an interlayer 15 disposed between the substrate 12 and the organic light management film 16. The interlayer 15 may be a thin metal layer, for example. Alternatively, the interlayer may be disposed between the organic light management film 16 and the transparent inorganic film 18.
Figure 4 illustrates the effect of the inorganic film 18 on the light emitted from the light source 10. For ease of illustration, only the inorganic film 18 and the organic light management film 16 are shown in Figure 4. In the structure of Figure 4, the organic light management film 16 and the inorganic film 18 have indices of refraction of m and n2, respectively, with ni < 1.7 and n2 > 1.7. A light ray 30 travels in the organic light management film 16 at an angle θi with respect to the normal 34 to the bottom surface 36 of the organic light management film 16. The light ray 30 is refracted at the interface of the organic light management film 16 and the inorganic film 18 due to the different indices of refraction for these materials according to known optical principles, and makes an angle θ2 with respect to the normal to the surface 38 of the inorganic film 18.
Figure 5 illustrates the effect of the inorganic film 18 on the light emitted from the light source 10 in the case where the organic light management film 16 includes a number of raised features 20. Figure 5 has the same structure as Figure 4 except for the raised features 20. In this case the raised features 20 are prismatic structures having prismatic surfaces, and the inorganic film 18 is conformal to the organic light management film 16. In a similar fashion to the light ray 30 in Figure 4, the light ray 30 in Figure 5 travels in the organic light management film 16 at an angle θι with respect to the normal 34 to the bottom surface 36 of the organic light management film 16. Again, the light ray 30 is refracted at interface of the organic light management film 16 and the inorganic film 18 due to the different indices of refraction for these materials according to known optical principles, h Figure 5, the light ray 30 passes from the inorganic film 18 to air or vacuum with an index of refraction of about 1.0. Because the top surface 39 of the organic light management film 16 is not parallel to that of the bottom surface 36, and because the inorganic film 18 is conformal to the organic light management film 16, in Figure 5, the light ray 30 may leave the inorganic film 18 in a direction which is normal to the bottom surface organic light management film 16 at an oblique angle, may leave the inorganic film 18 at an angle normal to bottom surface 36 of the organic light management film 16. Thus, Figure 5 illustrates an example of how oblique light rays may be redirected using the high index inorganic film 18.
The inorganic film 18 not only affects the directionality of light leaving the film 18, but also can selectively affect the polarization of the light, as disclosed in U.S. application serial no. 10/065,957, filed on December 4, 2002, entitled "POLARIZATION SENSITIVE OPTICAL SUBSTRATE", which is hereby incorporated by reference in its entirety.
Figures 6-8 illustrate embodiment of the invention where the inorganic films 18 and the organic light management films 16 alternate in optical structures, wherein the optical structures act as interference filters. An interference filter, as is known in the art, is a filter that controls the spectral composition of transmitted (and reflected) light energy in part through interference of light reflected at the layer interfaces of the films making up the filter.
For ease of illustration, only the inorganic films 18 and the organic light management films 16 are shown in Figures 6-8, not the light source 14 and substrate 12 of the embodiments of Figures 1-3.
Figure 6 illustrates an embodiment with two inorganic films 18 and two organic light management films 16 arranged in alternate fashion. The optical structure 70 of Figure 6 is arranged to operate as a narrow antireflection filter.
Figure 9 is a graph showing the % reflectance as a function of wavelength for normal light incidence on the optical structure 70 of Figure 6. Figure 9 shows the % reflectance specifically for the case where the index of refraction of the inorganic films 18 and the organic light management films 16 is 2.5 and 1.45, respectively, and where the layer thicknesses from the top to the bottom layer in Figure 6 is 17.35 rrm, 35.32 nm, 132.66 nm and 94.50 nm, respectively. Figure 7 illustrates an embodiment with a single inorganic film 18 and a single organic light management film 16 arranged as shown. The optical structure 80 of Figure 7 is arranged to operate as a wide antireflection filter.
Figure 10 is a graph showing the % reflectance as a function of wavelength for normal light incidence on the optical structure 80 of Figure 7. Figure 10 shows the % reflectance specifically for the case where the index of refraction of the inorganic film 18 and the organic light management film 16 is 2.05 and 1.38, respectively, and where the layer thicknesses of the inorganic film 18 and the organic light management film 16 in Figure 7 is 134.15 nm, 99.64 nm, respectively.
Figure 8 illustrates an embodiment with several inorganic films 18 and several organic light management films 16 arranged in alternate fashion. The optical structure 90 of Figure 8 is arranged to operate as a wide band reflection filter.
Figure 11 is a graph showing the % fransmittance as a function of wavelength for normal light incidence on the optical structure 90 of Figure 9. Figure 11 shows the % reflectance specifically for the case where the index of refraction of the inorganic films 18 and the organic light management films 16 is 2.35 and 1.45, respectively, and where the layer thicknesses from the top to the bottom layer in Figure 8 ranges between about 20 m l and about 225 nm, respectively. The total number of inorganic films 18 and the organic light management films 16 together is 59 for the graph of Figure 11. Of course in practice the total number of layers will vary depending upon the application.
Figure 12 is a schematic of an optical device 40 according to an embodiment of the present invention. The optical device 40 includes a modulation array 42 comprising a liquid crystal material. The modulation array selectively allows light to pass through a pixel of the array as is known in the art. The optical device 40 may be a liquid crystal display (LCD), for example. The optical device 40 may include elements of the optical structure described above with respect to Figure 1.
The optical device 40 includes a substrate 12, which may be a backlight, for example, including a light source 14. Disposed between the modulation array 42 and the substrate 12, or on the opposite side of the modulation array 42 from the substrate 12 are one or more organic light management films 16 (with an index of refraction less than 1.7) with a corresponding adjacent transparent inorganic film 18 (with an index of refraction greater than 1.7). The organic light management film 16 may be one or more of a quarter wave plate, brightness enhancing film, retardation foil, diffuser film, color filter, high pass filter, band pass filter, low pass filter, for example. If the organic light management film 16 is a color filter, it may be a color filter array with individual red, blue and green pixel sized filters, for example. If a filter, the filter might be used as a color selective transflector.
The organic light management film 16 and the transparent inorganic film 18 may also be disposed alternately in a number of layers.
The organic light management films 16 may have a plurality of raised features 20, such as prismatic features, for example. The transparent inorganic films 18 may be disposed conformally on their respective organic light management film 16 with the plurality of raised features 20.
The organic light management film 16 may comprise a substrate layer and a overlayer as in the embodiment of Figure 1, or just a substrate layer as in the embodiments of Figures 2 and 3. The organic light management film 16 and the transparent inorganic film 18 may also be arranged alternately as in the embodiments of Figures 6-8.
The transparent inorganic film 18 in the above embodiments of may be formed of inorganic materials such as, for example, metal oxides, such as titanium oxide and zinc oxide, or nitrides, such as silicon nitride, or oxynitrides, such as silicon oxynitride. The transparent inorganic film 18 may also be formed of ceramic compounds, such as boron carbon nitride. Thin transparent metal films may also be used for the transparent inorganic film 18. The transparent inorganic film 18 may also be formed of transparent conducting oxide coatings such as Indium Tin Oxide, Indium Oxide, Tin Oxide, or Cadmium Tin Oxide.
The material for the organic light management film 16 will depend upon the application, and may be, for example, an organic polymer such as polycarbonate. Method of forming transparent inorganic film
The transparent inorganic film 18 is preferably formed by depositing under vacuum in an enclosed deposition chamber. Because the film 18 is inorganic, there are a variety of deposition methods under vacuum in an enclosed deposition chamber which may be used. Suitable techniques for deposition of the transparent inorganic film 18 include physical vapor deposition techniques. These physical vapor deposition techniques include, for example, electron beam evaporation, thermal evaporation, and sputtering. Suitable techniques for deposition of the transparent inorganic film 18 also include chemical vapor deposition techniques. These chemical vapor deposition techniques include, for example, chemical vapor deposition, plasma assisted chemical vapor deposition, expanding thermal plasma deposition and atmospheric plasma chemical vapor deposition.
The raised features 20 either on the organic light management film 16, or on the transparent inorganic film 18, can be formed by conventional photolithography techniques, such as be depositing photoresist, exposing through a photomask, developing the photoresist to pattern it, followed by etching through the patterned photoresist.
The transparent inorganic film 18 may be deposited in a conformal fashion over existing raised features 20 in the organic light management film 16. However, for specific applications directional deposition either from normal angle or oblique angle relative to the substrate 12 maybe preferred.
Either before or after the step of depositing the transparent inorganic film 18 under vacuum, the organic light management film 16 may be disposed into an optical structure which includes a light source, such as onto a backlight, for example.
With directional coatings, specific portions of the features may be coated without coating the entire feature 20. Figure 13 illustrates an optical structure 50 where the raised features 20 are prismatic features, and only those portions of the features with a surface perpendicular to the direction from which the material is deposited are coated with a first transparent inorganic film 18 A. In this case, the organic light management film 16 will be effected by the first transparent inorganic film 18A only for those portions covered by the first transparent inorganic film 18 A.
The organic light management film 16 may comprise a substrate layer and an overlayer as in the embodiment of Figure 1, or just a substrate layer as in the embodiment of Figure 2.
Optionally, those portions of the organic light management film 16 not covered with the first transparent inorganic film 18 A, may be covered with a second transparent inorganic film 18B. Together the first transparent inorganic film 18A and the second fransparent inorganic film 18B make up the transparent inorganic film 18. The second fransparent inorganic film 18B may be made of the same or a different material from the first transparent inorganic film 18 A. Preferably the second transparent inorganic film 18B is made of a different material from the first transparent inorganic film 18 A with a different index of refraction. Thus, a light ray passing through the optical structure 50 will encounter a different index of refraction passing through the first transparent inorganic film 18A as compared to the second transparent inorganic film 18B.
The second transparent inorganic film 18B may be formed by directional deposition after the first transparent inorganic film 18A. In this case, after the first transparent inorganic film 18A is formed, the orientation of the substrate is changed relative to the direction from which the material is deposited so that a different surface is perpendicular to the direction from which the material is deposited to form the second transparent inorganic film 18B.
The thickness of the organic light management films 16 and the transparent inorganic films 18 in the above embodiments will depend on the application but are typically between 10 nm and 10,000 nm. The thickness of the optical structures in the above embodiments will also depend on the application but are typically between 100 nm and 5 cm.
While the invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope of the invention. Thus, the breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents.

Claims

WHAT IS CLAIMED IS:
1. An optical structure comprising:
a light source (14);
an organic light management film (16) having an index of refraction of less than 1.7 disposed above the light source (14); and
a transparent inorganic film (18) having an index of refraction of greater than 1.7 disposed adjacent the orgamc light management film (16).
2. The optical structure of claim 1, wherein the transparent inorganic film (18) is disposed on the organic light management film (16).
3. The optical structure of claim 1, wherein the transparent inorganic film (18) comprises a first transparent inorganic film (18A) and a second transparent inorganic film (18B), the first transparent inorganic film disposed on a first portion of the organic light management film and the second transparent inorganic film disposed on a second portion of the organic light management film different from the first portion.
4. The optical structure of claim 1, further comprising an interlayer (15) disposed between the light source (14) and the organic light management film (16) or between the organic light management film (16) and the transparent inorganic film (18).
5. The optical structure of claim 2, wherein the organic light management film (16) includes a plurality of raised features (20).
6. . The optical structure of claim 1, wherein the organic light management film (16) is one of a quarter wave plate, a brightness enhancing film, a retardation foil, a diffuser film, a color filter, a low pass filter, a band pass filter, a high pass filter, a color selective fransflector, a neutral density filter, an IR blocking filter an UV blocking filter and combinations thereof.
7. An optical device comprising:
a backlight (12) comprising a source of light;
a modulation array (42) comprising a liquid crystal material disposed above the backlight (12);
an organic light management film (16) having an index of refraction of less than 1.7 disposed above the backlight (12); and
a transparent inorganic film (18) having an index of refraction of greater than 1.7 disposed adjacent the organic light management film (16).
8. The optical device of claim 7, wherein the organic light management film (16) is disposed between the backlight (12) and the modulation array (42).
9. The optical device of claim 7, wherein the transparent inorganic film (18) is disposed on the organic light management film (16).
10. A method of forming an optical structure comprising:
providing an organic light management film (16) having an index of refraction of less than 1.7;
depositing under vacuum a transparent inorganic film (18) having an index of refraction of greater than 1.7 on the organic light management film (16); and
disposing the organic light management film (16) into an optical structure which includes a light source (14) before or after the step of depositing under vacuum.
EP03789876A 2002-12-04 2003-11-20 High index of refraction coated light management films Withdrawn EP1570303A1 (en)

Applications Claiming Priority (5)

Application Number Priority Date Filing Date Title
US65957 2002-12-04
US10/065,957 US6811274B2 (en) 2002-12-04 2002-12-04 Polarization sensitive optical substrate
US248129 2002-12-19
US10/248,129 US6951400B2 (en) 2002-12-04 2002-12-19 High index coated light management films
PCT/US2003/037116 WO2004051325A1 (en) 2002-12-04 2003-11-20 High index of refraction coated light management films

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EP1570303A1 true EP1570303A1 (en) 2005-09-07

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WO2008069162A1 (en) 2006-12-05 2008-06-12 Semiconductor Energy Laboratory Co., Ltd. Anti-reflection film and display device
WO2008069222A1 (en) 2006-12-05 2008-06-12 Semiconductor Energy Laboratory Co., Ltd. Plasma display panel and field emission display
WO2008069221A1 (en) 2006-12-05 2008-06-12 Semiconductor Energy Laboratory Co., Ltd. Plasma display panel and field emission display
WO2008069112A1 (en) 2006-12-05 2008-06-12 Semiconductor Energy Laboratory Co., Ltd. Plasma display panel and field emission display
WO2008069219A1 (en) 2006-12-05 2008-06-12 Semiconductor Energy Laboratory Co., Ltd. Antireflective film and display device
WO2008069163A1 (en) 2006-12-05 2008-06-12 Semiconductor Energy Laboratory Co., Ltd. Plasma display panel and field emission display
WO2008069164A1 (en) 2006-12-05 2008-06-12 Semiconductor Energy Laboratory Co., Ltd. Antireflection film and display device

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4556288A (en) * 1981-10-27 1985-12-03 Canon Kabushiki Kaisha Liquid crystal device with anti-reflection function in dielectric layer
EP0573905A1 (en) * 1992-06-08 1993-12-15 Minnesota Mining And Manufacturing Company Retroreflecting polarizer for presentation systems
TW594115B (en) * 1992-10-09 2004-06-21 Asahi Glass Co Ltd A liquid crystal display device and an illumination device for a direct viewing type display element
US5508091A (en) * 1992-12-04 1996-04-16 Photran Corporation Transparent electrodes for liquid cells and liquid crystal displays
FR2731806B1 (en) * 1994-03-17 1998-03-06 Lg Electronics Inc ANTI-REFLECTIVE LAYER FOR A DISPLAY DEVICE
US6545809B1 (en) * 1999-10-20 2003-04-08 Flex Products, Inc. Color shifting carbon-containing interference pigments

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO2004051325A1 *

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AU2003294393A1 (en) 2004-06-23
BR0316331A (en) 2005-09-27

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