WO2001014790A1 - Diffuse lighting arrangement - Google Patents

Diffuse lighting arrangement Download PDF

Info

Publication number
WO2001014790A1
WO2001014790A1 PCT/GB2000/003177 GB0003177W WO0114790A1 WO 2001014790 A1 WO2001014790 A1 WO 2001014790A1 GB 0003177 W GB0003177 W GB 0003177W WO 0114790 A1 WO0114790 A1 WO 0114790A1
Authority
WO
WIPO (PCT)
Prior art keywords
front
diffraction grating
light
spaced
light source
Prior art date
Application number
PCT/GB2000/003177
Other languages
French (fr)
Inventor
Robin James Thomas Clabburn
Original Assignee
Microsharp Corporation Limited
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 to GB9919689.1 priority Critical
Priority to GBGB9919689.1A priority patent/GB9919689D0/en
Application filed by Microsharp Corporation Limited filed Critical Microsharp Corporation Limited
Publication of WO2001014790A1 publication Critical patent/WO2001014790A1/en

Links

Classifications

    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS, OR APPARATUS
    • G02B6/00Light guides
    • G02B6/0001Light guides specially adapted for lighting devices or systems
    • G02B6/0011Light guides specially adapted for lighting devices or systems the light guides being planar or of plate-like form
    • G02B6/0033Means for improving the coupling-out of light from the light guide
    • G02B6/005Means 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
    • G02B6/0051Diffusing sheet or layer
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21LIGHTING
    • F21VFUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
    • F21V5/00Refractors for light sources
    • F21V5/002Refractors for light sources using microoptical elements for redirecting or diffusing light
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21LIGHTING
    • F21VFUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
    • F21V5/00Refractors for light sources
    • F21V5/02Refractors for light sources of prismatic shape
    • GPHYSICS
    • G02OPTICS
    • G02FDEVICES OR ARRANGEMENTS, THE OPTICAL OPERATION OF WHICH IS MODIFIED BY CHANGING THE OPTICAL PROPERTIES OF THE MEDIUM OF THE DEVICES OR ARRANGEMENTS FOR THE CONTROL OF THE INTENSITY, COLOUR, PHASE, POLARISATION OR DIRECTION OF LIGHT, e.g. SWITCHING, GATING, MODULATING OR DEMODULATING; TECHNIQUES OR PROCEDURES FOR THE OPERATION THEREOF; FREQUENCY-CHANGING; NON-LINEAR OPTICS; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00Devices 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
    • G02F1/01Devices 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 
    • G02F1/13Devices 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
    • G02F1/133Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333Constructional arrangements; Manufacturing methods
    • G02F1/1335Structural association of cells with optical devices, e.g. polarisers or reflectors
    • G02F1/1336Illuminating devices
    • G02F1/133602Direct backlight
    • G02F1/133603Direct backlight with LEDs
    • GPHYSICS
    • G02OPTICS
    • G02FDEVICES OR ARRANGEMENTS, THE OPTICAL OPERATION OF WHICH IS MODIFIED BY CHANGING THE OPTICAL PROPERTIES OF THE MEDIUM OF THE DEVICES OR ARRANGEMENTS FOR THE CONTROL OF THE INTENSITY, COLOUR, PHASE, POLARISATION OR DIRECTION OF LIGHT, e.g. SWITCHING, GATING, MODULATING OR DEMODULATING; TECHNIQUES OR PROCEDURES FOR THE OPERATION THEREOF; FREQUENCY-CHANGING; NON-LINEAR OPTICS; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00Devices 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
    • G02F1/01Devices 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 
    • G02F1/13Devices 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
    • G02F1/133Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333Constructional arrangements; Manufacturing methods
    • G02F1/1335Structural association of cells with optical devices, e.g. polarisers or reflectors
    • G02F1/1336Illuminating devices
    • G02F1/133602Direct backlight
    • G02F1/133606Direct backlight including a specially adapted diffusing, scattering or light controlling members
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21LIGHTING
    • F21YINDEXING SCHEME ASSOCIATED WITH SUBCLASSES F21K, F21L, F21S and F21V, RELATING TO THE FORM OR THE KIND OF THE LIGHT SOURCES OR OF THE COLOUR OF THE LIGHT EMITTED
    • F21Y2115/00Light-generating elements of semiconductor light sources
    • F21Y2115/10Light-emitting diodes [LED]
    • GPHYSICS
    • G02OPTICS
    • G02FDEVICES OR ARRANGEMENTS, THE OPTICAL OPERATION OF WHICH IS MODIFIED BY CHANGING THE OPTICAL PROPERTIES OF THE MEDIUM OF THE DEVICES OR ARRANGEMENTS FOR THE CONTROL OF THE INTENSITY, COLOUR, PHASE, POLARISATION OR DIRECTION OF LIGHT, e.g. SWITCHING, GATING, MODULATING OR DEMODULATING; TECHNIQUES OR PROCEDURES FOR THE OPERATION THEREOF; FREQUENCY-CHANGING; NON-LINEAR OPTICS; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00Devices 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
    • G02F1/01Devices 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 
    • G02F1/13Devices 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
    • G02F1/133Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333Constructional arrangements; Manufacturing methods
    • G02F1/1335Structural association of cells with optical devices, e.g. polarisers or reflectors
    • G02F1/1336Illuminating devices
    • G02F1/133602Direct backlight
    • G02F1/133611Direct backlight including means for improving the brightness uniformity
    • GPHYSICS
    • G02OPTICS
    • G02FDEVICES OR ARRANGEMENTS, THE OPTICAL OPERATION OF WHICH IS MODIFIED BY CHANGING THE OPTICAL PROPERTIES OF THE MEDIUM OF THE DEVICES OR ARRANGEMENTS FOR THE CONTROL OF THE INTENSITY, COLOUR, PHASE, POLARISATION OR DIRECTION OF LIGHT, e.g. SWITCHING, GATING, MODULATING OR DEMODULATING; TECHNIQUES OR PROCEDURES FOR THE OPERATION THEREOF; FREQUENCY-CHANGING; NON-LINEAR OPTICS; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F2203/00Function characteristic
    • G02F2203/22Function characteristic diffractive

Abstract

A diffuse lighting arrangement, for example for backlighting an LCD display, comprises a two dimensional array of individual localised light sources, such as light emitting diodes (12) and at least one two dimensional grating (14) spaced in front of that array. A light diffusing plate or sheet (16) is preferably disposed in front of the diffraction grating (14).

Description

Title: " Diffuse Lighting Arrangement"

THIS INVENTION relates to an arrangement for providing a diffuse light source, for example, as a back-lighting arrangement for LCD displays, such as are utilised in portable computers.

Conventionally, back-lighting arrangements for LCD displays in portable computers and the like have comprised edge-lit reflector blocks, generally edge-lit by a linear light source such as a fluorescent tube, the reflector blocks being configured internally so that light entering the block from the source along one edge is reflected by reflective surfaces bounding the block and/or by total internal reflection at angled surfaces contrived within the block, to emerge from a front face of the block at various locations on that front face and along various exit paths. An alternative back-lighting arrangement which has been used in the past comprises a cold-cathode fluorescent tube in a sinuous shape to provide an array of laterally parallel bars, interconnected by bends, backed by a reflector. In either case, a diffuser is normally disposed in front of the edge-lit reflector block or the sinuous discharge tube in an attempt to provide as far as possible an evenly light-emitting source with no perceptible "hot spots". The diffusers required in either case must generally have a strong diffusive effect to avoid perception of the shape and configuration of the underlying light source or reflector arrangement, and consequently most of the light passing through the diffuser passes in directions too far removed from the normal viewing angle to serve usefully to illuminate the display. (With a view to increasing the amount of light which is at least initially directed normal to the plane of the display, it is known to interpose one or more layers of prismatic transparent plastics films, (also referred to as brightness-enhancing films) between the diffuser and the remainder of the back-lighting arrangement, but this expedient besides being less than wholly successful, also adds to the size (i.e. depth) of the display, to manufacturing complexity and, albeit to a minor extent, to the weight of the apparatus). These prior back-lighting arrangements are thus relatively inefficient in terms of energy usage, which is a significant consideration with battery-powered apparatus such as portable computers, and additionally tend to generate unwanted heat. The light sources, such as cold- cathode fluorescent discharge tubes, used in such prior displays, may also require high voltages, requiring complex additional electrical circuitry, resulting in further energy inefficiency and added weight and manufacturing costs.

Coloured LEDs (light emitting diodes) have been available for several years. However, white LEDs have been created and are now commercially available with increasing brightness and lower cost such that they are now considered cost effective when compared with incandescent and fluorescent sources of similar brightness. LEDs have the added advantage of low operating voltage.

In accordance with one aspect of the present invention, it is proposed to use, as a diffuse light source suitable for back-illumination of LCD displays and like applications, an array of light- emitting diodes (LEDs) to afford an efficient means of generating light with low voltages such as those generally available in and utilised by portable computers and the like and without significant heat generation, etc. Thus, in accordance with the present invention, there is provided an LCD display which is back-lit by a lighting arrangement utilising one or more light- emitting diodes (LEDs) as a light source.

In an alternative embodiment of the present invention, there is provided a lighting arrangement comprising one or more LEDs as a light source suitable for domestic or commercial lighting or as a light box for the detailed examination of light transparent images such as X-ray photographs.

In order to provide uniform lighting, i.e. so that perception of individual LEDs does not intrude upon perception of the display, some additional measure is required unless the LEDs are to be so numerous and closely packed as to present, visually, a continuous illuminated surface. Given the effectiveness, or lack of it, of conventional diffusers, merely placing such a conventional diffuser in front of an aπay of even a moderate number of LEDs does not allow the desired uniformity of illumination to be achieved without significant loss of brightness.

It is a further object of the present invention in a preferred embodiment to provide a means whereby a uniform illumination can be provided by an array of a relatively few LEDs.

According to another aspect of the invention, therefore, there is provided a diffusive lighting arrangement comprising at least one localised light source, at least one diffraction grating spaced in front of said light source and at least one diffuser spaced in front of the diffraction grating.

The diffused lighting arrangement may, for example, be a back-lighting arrangement for an LCD display or the like. The effect of the diffraction grating, as described in more detail later, is to create from a single or point light source such as a laser, pixel or LED a diffracted light pattern comprising zero, first and subsequent orders. However, when a multi wavelength or "white" light source is used, the grating will also tend to split the light into the primary colours. Although the primary use of the diffuser is to produce a more uniform light source, a secondaiy function is to combine colours from separate coloured LEDs or recombine the light from white LEDs such that the lighting anangement exliibits both uniform colour and brightness.

An embodiment of the invention is described below by way of example with reference to the accompanying drawings in which: -

FIGURE 1 is a schematic perspective exploded view illustrating a back-lighting arrangement in accordance with the invention applied to an LCD display, for example of a portable computer,

FIGURE 2 is a schematic cross sectional view of such a display, and

FIGURE 3 is a schematic cross-sectional view illustrating the effect of the diffraction grating in an anangement in accordance with the invention.

Referring to Figures 1 and 2, reference 10 represents a back plane, which may, for example, simply be a rear wall of a display structure supporting an anay of light-emitting diodes (LEDs) 12, the anay comprising rows and columns of LEDs 12. The LEDs 12 have, of course, conductors which are connected in manner known per se with an electrical power supply (not shown). The back plane or support 10 preferably has a reflective coating on its front surface, (i.e. on the side on which the LEDs are exposed) to ensure that any light emitted or scattered in the rearward direction is reflected forwards towards the LCD cell (see below). The back plane 10 may, for example, comprise a printed circuit board on which the LEDs are soldered and which connects the LEDs to a power supply. The reflecting coating may be applied to the front of that printed circuit board or may be provided by a separate reflective sheet mounted slightly in front of the printed circuit board and having apertures to receive the LEDs.

By way of example, the individual LEDs may have a light-emitting area of around 2 mm squared and may be aπanged 5 to 10 mm apart.

Located in front of the aιτay of LEDs 12, and extending parallel with the latter and thus with the back plane 10, is a two-dimensional light diffracting sheet 14 which for convenience will be refeπed to hereafter as a diffraction grating. The grating 14 may indeed simply be a sheet of glass or transparent plastics having a surface on which is formed by a rectangular grid comprising two sets of mutually perpendicular grid lines, scored, etched or impressed upon such surface. However, it is prefeιτed to use a diffracting sheet 14 such as described in GB-2314943 comprising a plastics sheet having on one surface thereof a regular array of upstanding cylinders, conical frustums or other geometrical features taking advantage of the possibility afforded for tailoring the relative intensities of the different diffraction orders, for example, by appropriate design of the individual upstanding features. Typically, the individual cylinders or like features in such a diffracting sheet may be 25 μ in height and diameter and spaced 40μ apart. Such diffraction sheets or gratings may be readily produced by embossing plastics for example. (As described in GB- 2314943, the relief features may be covered or the regions between features filled, by a medium of different refractive index to afford a diffracting sheet smooth on both sides). Disposed in front of the grating 14, spaced therefrom and parallel therewith, is a diffusing screen 16, which may be of conventional form or may be of the kind disclosed, for example, in European Patent Application No. 0294122 and comprising an anay of minute graded refractive index lenses or like optical features. Finally, a conventional LCD cell structure 18, (represented in Figure 2 as a single sheet since the structure of such cells is well known), is spaced in front of the diffuser 16 and again is ananged parallel with the back plane 10, sheet 14, and diffuser 16. It will be appreciated that where the display is intended for a portable computer or the like, the LCD cell 18 comprises an array of individually activatable elements providing respective "pixels" of a display.

Referring to Figure 3, and assuming, for simplicity, the light from a single LED 12 of the aιτay to be monochromatic and coherent, a given beam from the LED 12 to a given point, A, on the diffraction grating 14 will be diffracted by the latter to form, in addition to a zero order beam I0, transmitted through the grating, first, second, third, etc. order beams Ils I2, I3 etc. as illustrated, diverging from the grating at different angles. Because of the two-dimensional nature of the diffraction grating 14, the beam I will be diffracted into first, second, third, etc. order beams not only in a plane perpendicular to the plane of the grating and to a first set of parallel grating lines, but also in a perpendicular plane, also perpendicular to the plane of the grating, parallel to the second set of grating lines, and additionally into beams in various other planes perpendicular to the plane of the grating and thus will give rise to a relatively complex bundle of diffracted rays emerging from the grating 14 towards the diffuser 16. A corresponding effect is provided, of course, on each ray passing from the LED 12 to any other point on the diffraction grating 14 (e.g. point B) and thus at coιτesponding different angles. Coπesponding effects are, of course, provided by each of the LEDs, with the result that, from the perspective of the diffuser 16, the diffraction grating 14 acts as an aιτay of a veiy large number of individual light sources. The effect is in some ways analogous to the effect of a random diffuser, but because of the organised and "tailored" nature of the grating 14, the "spread" of light from each LED after diffraction by grating 14, can be engineered to be predominantly in the desired direction towards the LCD cell. The grating 14 is thus more efficient than and provides more unifonn illumination than would a conventional diffuser. By way of example by appropriate detailed design of the diffraction grating, it is possible to arrange matters so that, for example, the intensity of the first-order diffracted beams is substantially the same as that of the zero order beam transmitted through the grating whilst the intensity of high order diffracted beams is significantly reduced. By such design teclmiques, and appropriate selection of the spacing between the diffraction grating and the LED aιτay, it is possible in effect to multiply the number of light sources and reduce their spacing, from a point of view in front of the grating, and to approach the ideal of an infinite number of uniformly arranged light sources, of the same intensity spaced apart infinitesimally. It will be understood that, in principle, the more light sources per unit area of the back-lighting anay, the less powerful (i.e. less strongly diffusive) need be the diffuser to achieve uniformity of illumination, and the more efficient the back-lighting anangement becomes in directing light forwardly into the region from which the display is likely to be viewed. The diffraction grating or gratings 14 may take any of many different forms. GB2314943 describes various diffraction gratings or diffraction arcays which may be formed for example, by embossing plastics, and which are described in GB2314943 as being of use as depixellators. Both planar and surface relief diffracting arrays are disclosed. These devices are based on diffracting substructures which create first and second order diffracted sources from a single point source. The detailed design determines the relative strength of the primary first and second orders. The diffuser 16 serves to disperse only slightly the diffracted rays striking it from the diffraction grating 14, with the result that, from the perspective of the LCD cell 18, the diffuser 16 is effectively a uniform diffusive light source. The diffuser 16 is preferably a relatively weak "random" diffuser and thus has little or no tendency to absorb light or scatter it back unduly.

It will be appreciated that it is normally desirable that the LCD screen should be illuminated by white light rather than by monochromatic light. To this end, the LEDs 12 may comprise red, green and blue LEDs interspersed with one another on the supporting plane 10. However, more preferably, the LEDs 12 may be white light LEDs of the sort which have recently become available.

It will be understood that, depending upon the number and size of LEDs available, two or more gratings 14 may be provided, one spaced in front of the other, instead of the single grating 14. In this case, of course, different such gratings may comprise each a single set of mutually parallel grid lines, with the grid lines of each grating being perpendicular to or at a selected different angle to the grid lines of the other grating or gratings. Likewise several random diffusers may be provided instead of the diffuser 16 or one diffuser may be interposed between two gratings 14, according to the properties desired.

In the present specification "comprise" means "includes or consists of and "comprising" means "including or consisting of.

The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for perfoπning the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

Claims

1. A diffusive lighting arrangement comprising at least one localised light source and at least one diffraction grating spaced in front of the light source.
2. A diffusive lighting arrangement according to claim 1, including at least one diffuser spaced in front of the diffraction grating.
3. A diffuse lighting arrangement comprising a two dimensional array of localised light sources, at least one two-dimensional diffraction grating spaced from said array and in front of the latter, and at least one diffuser disposed in front of said diffraction grating.
4. A back-lighting anangement suitable for an LCD display, the backlighting arrangement comprising at least one localised light source, at least one diffraction grating spaced in front of said light source and at least one diffuser spaced in front of the diffraction grating.
5. A back-lighting anangement suitable for an LCD display, the backlighting anangement comprising a two-dimensional anay of localised light sources, at least one two-dimensional diffraction grating spaced from said array and in front of the latter, and at least one diffuser disposed in front of said diffraction grating and spaced therefrom.
6. An arrangement according to any of claims 1 to 4 wherein the or each said localised light source comprises a light-emitting diode (LED).
7. An anangement according to any preceding claim including a second diffraction grating spaced in front of the first-mentioned diffraction grating.
8. An aiTangement according to claim 6 wherein the or each said localised light source comprises a white-light light-emitting diode (LED).
PCT/GB2000/003177 1999-08-19 2000-08-16 Diffuse lighting arrangement WO2001014790A1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
GB9919689.1 1999-08-19
GBGB9919689.1A GB9919689D0 (en) 1999-08-19 1999-08-19 Back-lighting arrangement and the like

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
AU67068/00A AU6706800A (en) 1999-08-19 2000-08-16 Diffuse lighting arrangement
EP00954707A EP1210548A1 (en) 1999-08-19 2000-08-16 Diffuse lighting arrangement
JP2001518627A JP2003507864A (en) 1999-08-19 2000-08-16 Diffuse illumination device

Publications (1)

Publication Number Publication Date
WO2001014790A1 true WO2001014790A1 (en) 2001-03-01

Family

ID=10859469

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/GB2000/003177 WO2001014790A1 (en) 1999-08-19 2000-08-16 Diffuse lighting arrangement

Country Status (5)

Country Link
EP (1) EP1210548A1 (en)
JP (1) JP2003507864A (en)
AU (1) AU6706800A (en)
GB (1) GB9919689D0 (en)
WO (1) WO2001014790A1 (en)

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2002079862A2 (en) * 2001-03-30 2002-10-10 Koninklijke Philips Electronics N.V. Direct backlighting for liquid crystal displays
FR2848288A1 (en) * 2002-12-05 2004-06-11 Schneider Electric Ind Sas An LED lighting
EP1594172A2 (en) * 2004-05-07 2005-11-09 LumiLeds Lighting U.S., LLC Multi-colored LED array with improved brightness profile and color uniformity
US7583331B2 (en) 2004-07-27 2009-09-01 Dolby Laboratories Licensing Corporation Diffuser for light from light source array and displays incorporating same
US7623197B2 (en) 2005-03-10 2009-11-24 Nanogate Advanced Materials Gmbh Flat screen
US20120224018A1 (en) * 2011-03-04 2012-09-06 Canon Kabushiki Kaisha Optical Writing Head and Image Forming Apparatus
US8487519B2 (en) 2002-11-13 2013-07-16 Heptagon Micro Optics Pte. Ltd. Light emitting device
JP2015506071A (en) * 2011-12-16 2015-02-26 コーニンクレッカ フィリップス エヌ ヴェ Optical device comprising a diffractive optical element
US9519184B2 (en) 2007-07-19 2016-12-13 Samsung Electronics Co., Ltd. Backlight unit
US9711111B2 (en) 2008-06-25 2017-07-18 Dolby Laboratories Licensing Corporation High dynamic range display using LED backlighting, stacked optical films, and LCD drive signals based on a low resolution light field simulation

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4688553B2 (en) * 2005-04-18 2011-05-25 京セラ株式会社 A light-emitting device and a lighting device
JP4788184B2 (en) * 2005-04-26 2011-10-05 ソニー株式会社 Backlight device and a liquid crystal display device
JP4701334B2 (en) * 2006-01-27 2011-06-15 株式会社オプトデザイン Planar illumination light source device and a surface illuminating device using the same
JP4939970B2 (en) * 2007-02-20 2012-05-30 ニューパラダイムテクノロジー株式会社 Planar light emitting structure
JPWO2009004740A1 (en) * 2007-06-29 2010-08-26 アーベル・システムズ株式会社 led lighting device using a diffraction member
JP2011222421A (en) * 2010-04-13 2011-11-04 Asahi Kasei E-Materials Corp Light-emitting device

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0641967A1 (en) * 1993-09-03 1995-03-08 MAGNETI MARELLI S.p.A. Lighting device, particularly for motor vehicles
EP0704655A1 (en) * 1994-09-30 1996-04-03 CARELLO S.p.A. Light guide lighting system for forming a thin lighting device
EP0802446A1 (en) * 1995-11-06 1997-10-22 Seiko Epson Corporation Illuminator, liquid crystal display using the illuminator and electronic device
GB2314943A (en) 1996-07-01 1998-01-14 Nashua Corp Projection or depixelating screen
US5803579A (en) * 1996-06-13 1998-09-08 Gentex Corporation Illuminator assembly incorporating light emitting diodes
EP1016817A1 (en) * 1998-12-30 2000-07-05 Nokia Mobile Phones Ltd. A backlighting light pipe for illuminating a flat-panel display

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0641967A1 (en) * 1993-09-03 1995-03-08 MAGNETI MARELLI S.p.A. Lighting device, particularly for motor vehicles
EP0704655A1 (en) * 1994-09-30 1996-04-03 CARELLO S.p.A. Light guide lighting system for forming a thin lighting device
EP0802446A1 (en) * 1995-11-06 1997-10-22 Seiko Epson Corporation Illuminator, liquid crystal display using the illuminator and electronic device
US5803579A (en) * 1996-06-13 1998-09-08 Gentex Corporation Illuminator assembly incorporating light emitting diodes
GB2314943A (en) 1996-07-01 1998-01-14 Nashua Corp Projection or depixelating screen
EP1016817A1 (en) * 1998-12-30 2000-07-05 Nokia Mobile Phones Ltd. A backlighting light pipe for illuminating a flat-panel display

Cited By (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2002079862A3 (en) * 2001-03-30 2003-02-20 Koninkl Philips Electronics Nv Direct backlighting for liquid crystal displays
WO2002079862A2 (en) * 2001-03-30 2002-10-10 Koninklijke Philips Electronics N.V. Direct backlighting for liquid crystal displays
US8487519B2 (en) 2002-11-13 2013-07-16 Heptagon Micro Optics Pte. Ltd. Light emitting device
FR2848288A1 (en) * 2002-12-05 2004-06-11 Schneider Electric Ind Sas An LED lighting
EP1594172A2 (en) * 2004-05-07 2005-11-09 LumiLeds Lighting U.S., LLC Multi-colored LED array with improved brightness profile and color uniformity
EP1594172A3 (en) * 2004-05-07 2012-06-13 Philips Lumileds Lighting Company LLC Multi-colored LED array with improved brightness profile and color uniformity
US7583331B2 (en) 2004-07-27 2009-09-01 Dolby Laboratories Licensing Corporation Diffuser for light from light source array and displays incorporating same
US8692956B2 (en) 2004-07-27 2014-04-08 Dolby Laboratories Licensing Corporation Diffuser for light from light source array and displays incorporating same
US7973878B2 (en) 2004-07-27 2011-07-05 Dolby Laboratories Licensing Corporation Diffuser for light from light source array and displays incorporating same
US8212966B2 (en) 2004-07-27 2012-07-03 Dolby Laboratories Licensing Corporation Diffuser for light from light source array and displays incorporating same
US7623197B2 (en) 2005-03-10 2009-11-24 Nanogate Advanced Materials Gmbh Flat screen
US9519184B2 (en) 2007-07-19 2016-12-13 Samsung Electronics Co., Ltd. Backlight unit
US9711111B2 (en) 2008-06-25 2017-07-18 Dolby Laboratories Licensing Corporation High dynamic range display using LED backlighting, stacked optical films, and LCD drive signals based on a low resolution light field simulation
US20120224018A1 (en) * 2011-03-04 2012-09-06 Canon Kabushiki Kaisha Optical Writing Head and Image Forming Apparatus
US9278546B2 (en) * 2011-03-04 2016-03-08 Canon Kabushiki Kaisha Optical writing head and image forming apparatus
JP2015506071A (en) * 2011-12-16 2015-02-26 コーニンクレッカ フィリップス エヌ ヴェ Optical device comprising a diffractive optical element

Also Published As

Publication number Publication date
JP2003507864A (en) 2003-02-25
EP1210548A1 (en) 2002-06-05
GB9919689D0 (en) 1999-10-20
AU6706800A (en) 2001-03-19

Similar Documents

Publication Publication Date Title
US7311431B2 (en) Light-emitting apparatus having a plurality of adjacent, overlapping light-guide plates
EP0308828B1 (en) Illuminator and display panel employing it
US5894539A (en) Line light source having light pipe with rectangular cross-section
KR100499140B1 (en) Backlight unit
KR100518660B1 (en) Illumination system with light recycling to enhance brightness
KR100586968B1 (en) Led package and backlight assembly for lcd device comprising the same
JP4838986B2 (en) Generator of the luminance profile
CN100381903C (en) Light guide panel of edge-light type backlight system and edge-light type backlight system employing the same
KR100325673B1 (en) Lens film and plane light source device
EP1397610B1 (en) Compact illumination system and display device
US7537374B2 (en) Edge-lit backlight having light recycling cavity with concave transflector
RU2237932C2 (en) Light panel
US6330111B1 (en) Lighting elements including light emitting diodes, microprism sheet, reflector, and diffusing agent
JP4249631B2 (en) Backlight unit
JP3843393B2 (en) Planar lighting device
JP4925642B2 (en) A backlight unit and a liquid crystal display device employing the same
Feng et al. Novel integrated light-guide plates for liquid crystal display backlight
US7458714B2 (en) Optical plate and backlight module using the same
US6139163A (en) Planar light source unit
JP5702151B2 (en) Hollow backlight having a structured film
US20040109105A1 (en) Backlight unit and liquid crystal display device
US7614775B2 (en) Light guide member, planar lighting device using the same, and rod-type lighting device
JP5011151B2 (en) The liquid crystal display devices
US8462292B2 (en) Optically transmissive substrates and light emitting assemblies and methods of making same, and methods of displaying images using the optically transmissive substrates and light emitting assemblies
KR100484365B1 (en) Surface light source device of side light type, liquid crystal display and light guide plate

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AE AL AM AT AU AZ BA BB BG BR BY CA CH CN CR CU CZ DE DK DM EE ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MA MD MG MK MN MW MX NO NZ PL PT RO RU SD SE SG SI SK SL TJ TM TR TT TZ UA UG US UZ VN YU ZA ZW

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): GH GM KE LS MW MZ SD SL SZ TZ UG ZW AM AZ BY KG KZ MD RU TJ TM AT BE CH CY DE DK ES FI FR GB GR IE IT LU MC NL PT SE BF BJ CF CG CI CM GA GN GW ML MR NE SN TD TG

121 Ep: the epo has been informed by wipo that ep was designated in this application
DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
WWE Wipo information: entry into national phase

Ref document number: 2000954707

Country of ref document: EP

WWP Wipo information: published in national office

Ref document number: 2000954707

Country of ref document: EP

WWE Wipo information: entry into national phase

Ref document number: 10049402

Country of ref document: US

REG Reference to national code

Ref country code: DE

Ref legal event code: 8642

WWW Wipo information: withdrawn in national office

Ref document number: 2000954707

Country of ref document: EP