GB2384101A - Lighting assembly - Google Patents

Lighting assembly Download PDF

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Publication number
GB2384101A
GB2384101A GB0200481A GB0200481A GB2384101A GB 2384101 A GB2384101 A GB 2384101A GB 0200481 A GB0200481 A GB 0200481A GB 0200481 A GB0200481 A GB 0200481A GB 2384101 A GB2384101 A GB 2384101A
Authority
GB
United Kingdom
Prior art keywords
lighting assembly
light
liquid crystal
crystal display
light source
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Withdrawn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
GB0200481A
Other versions
GB0200481D0 (en
Inventor
David Thomas Summerland
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.)
BPC CIRCUITS Ltd
Original Assignee
BPC CIRCUITS 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 BPC CIRCUITS Ltd filed Critical BPC CIRCUITS Ltd
Priority to GB0200481A priority Critical patent/GB2384101A/en
Publication of GB0200481D0 publication Critical patent/GB0200481D0/en
Publication of GB2384101A publication Critical patent/GB2384101A/en
Withdrawn legal-status Critical Current

Links

Classifications

    • 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 
    • G02F1/23—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  for the control of the colour
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21S—NON-PORTABLE LIGHTING DEVICES; SYSTEMS THEREOF; VEHICLE LIGHTING DEVICES SPECIALLY ADAPTED FOR VEHICLE EXTERIORS
    • F21S10/00—Lighting devices or systems producing a varying lighting effect
    • F21S10/02—Lighting devices or systems producing a varying lighting effect changing colors
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
    • F21V14/00—Controlling the distribution of the light emitted by adjustment of elements
    • F21V14/003—Controlling the distribution of the light emitted by adjustment of elements by interposition of elements with electrically controlled variable light transmissivity, e.g. liquid crystal elements or electrochromic devices
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
    • F21V9/00—Elements for modifying spectral properties, polarisation or intensity of the light emitted, e.g. filters
    • F21V9/40—Elements for modifying spectral properties, polarisation or intensity of the light emitted, e.g. filters with provision for controlling spectral properties, e.g. colour, or intensity
    • 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
    • G02F1/1343—Electrodes
    • G02F1/134309—Electrodes characterised by their geometrical arrangement
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
    • Y02B20/00—Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps

Abstract

A lighting assembly 10 has a conical housing 12 having a light source 14 adjacent one end of the housing 12 and a shutter arrangement 16 at the large diameter output end of the housing 12. The shutter arrangement 16 includes a liquid crystal display (LCD) 18 disposed between a plurality of coloured filters 20 (for example cyan, magenta and yellow) and a cover 22. The LCD 18 includes a plurality of cells, each cell being selectively controllable between an open position, in which light may pass through the LCD 18, and a closed position, in which light may not pass through the LCD 18. The lighting assembly enables the output colour of light from the assembly to be selectively altered. The light source 14 may be a compact fluorescent lamp having a uniform light distribution, which can be positioned with relative simplicity to direct light towards the output end of the housing 12.

Description

<Desc/Clms Page number 1>
TITLE: Lighting assembly The present invention relates to a lighting assembly, more particularly, but not exclusively, to a lighting assembly for selectively controlling the output colour from a light source.
Light beams are commonly used to create a pleasurable effect in visual displays for public entertainment, for example in theatre or at musical events. In particular, a plurality of light beams each having a selectively changeable colour are used to create atmosphere within a theatrical or musical performance.
It is known to provide a lighting assembly which enables an area within the beam angle of a light source, such as a lamp, to be set to any colour in the visible spectrum. Typically, such a lighting assembly includes a plurality of different coloured bulbs, usually, but not always, red, green and blue, or a corresponding number of filters, usually, but not always, dichroic filters.
Liquid crystal display (LCD) projectors having a plurality of light filter display panels are also known, which filtered, green and blue signals from projection lamps, e. g. for projecting the image from a transparency or the like. Hence, LCD projectors can also be used to enable an area within the beam angle of a lamp to be set to any colour in the visible spectrum. However, LCD projectors use multiplexed display technology, in which particular cells of a display panel are activated by selecting a row and column from a predefined matrix. The disadvantage of this technology is that standard LCD displays have a low contrast ratio, i. e. the difference between the amount of light which is passed through the display when the LCD is off and the amount of light which is passed through the display when the LCD is on.
For example, a multiplexed LCD may only pass 50% of the light when on and 40 % of the light when off, having a contrast ratio of 1.25 to 1.
It is an object of the invention to provide an improved lighting assembly for selectively controlling the output colour from a light source.
<Desc/Clms Page number 2>
According to the broadest aspect of the present invention, there is provided a lighting assembly for selectively controlling the output colour from a light source comprising a housing having a light source, a liquid crystal display (LCD) and a plurality of coloured filters interposed in the path of light from the light source, wherein the LCD includes a plurality of cells, each cell being selectively controllable between an open position, in which light may pass through the LCD, and a closed position, in which light may not pass through the LCD, to enable the output of light from the lighting assembly to be selectively altered.
The lighting assembly achieves the same result as the prior art assembly referred to above but has no moving mechanical parts. Hence, the lighting assembly has the advantage of a relatively simple mechanical construction which is cost effective and easily maintainable.
The cells are preferably directly actuable.
The contrast ratio for the LCD having directly actuable cells is higher than that which is achievable with a multiplexed LCD, as described above. This is of particular advantage in obtaining a controlled colour output.
In a preferred embodiment, the light source is a compact fluorescent lamp.
A compact fluorescent lamp having a uniform light distribution can be used in the
lighting assembly. This is particularly advantageous, in that compact fluorescent lamps 1- in are widely available, i. e. from a local hardware outlet, and are relatively inexpensive and energy efficient. Further, a compact fluorescent lamp has a very long lamp life, typically between 10,000 to 20,000 hrs, and runs very cool with no hot spots. It also is a lowpressure lamp which is not prone to explosion, so is safe for use in public areas with little or no external protection. Moreover, a compact fluorescent lamp having a uniform light distribution can be positioned with relative simplicity to direct light towards the output end of the housing.
<Desc/Clms Page number 3>
Conveniently, the internal walls of the housing are reflective for reflecting light emitted from the light source to the output end of the housing.
The invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a diagrammatic cross-sectional view through a lighting assembly according to the invention; and
Figure 2 is a diagrammatic view from the front of the lighting assembly of Figure 1.
A lighting assembly is indicated generally at 10 and includes a frusto-conical housing 12 having a circular cross-section in plan view (not shown). A light source in the form of a compact fluorescent lamp 14 is securably mounted in the smaller diameter end of the housing 12 for connection to a power source (not shown).
The housing 12 is made from spun aluminium and acts as a reflector, to cause light emitted from the lamp 14 to be at least partially reflected within the walls of the housing 12, to provide a substantially even and flat distribution of light at its large diameter end.
A shutter arrangement 16 is provided over the large diameter end of the housing 12. The shutter arrangement 16 includes a liquid crystal display (LCD) 18 disposed between a plurality of coloured filters, indicated at 20, provided on the left hand side as viewed, and a cover 22 on the outer side of the LCD 18.
The LCD 18 is polygonal and consists of a plurality of shutter sectors 24, each shutter sector 24 being divided into a plurality of brightness cells 26 of radially increasing area.
As can be seen from Figure 2, in this embodiment the LCD 18 has nine shutter segments, each segment having six brightness cells. Hence, the LCD 18 has a"spider's web" configuration.
<Desc/Clms Page number 4>
Each brightness cell 26 is selectively operable by, direct actuation, between an open position, in which light from the lamp 14 may pass through the shutter arrangement 16, and a closed position, in which light from the lamp 14 may not pass through the shutter
arrangement 16.
1 In this embodiment, the coloured filters 20 consist of three groups of three different coloured filters, cyan 28, magenta 30 and yellow 32, which are arranged at radially spaced intervals on the inner surface of the LCD 18, to provide an even distribution of light from the housing 12.
By selectively opening and/or closing individual brightness cells 26, a binary build up of light output is available on each colour filter 20, which allows the light output to be adjusted to a predetermined percentage for each filter, for selectively controlling the output colour from the lamp 14. Hence, the LCD 18 acts as a shutter, to let different amounts of light pass through the filters 20, to enable the output from the lamp 14 to be set to any colour in the visible spectrum.
With each of the brightness cells in the open position (i. e. 100% light output for each filter 20), an output of white light is achievable. By selectively closing the outer brightness cells, for example, a progressively duller light output can be achieved. By combining various outputs from each filter 20, the output colour from the lighting assembly can be selectively controlled.
For example, a blue output colour can be achieved by 95% cyan and 92% magenta. By way of further example, an orange output colour can be achieved by 3% cyan, 39% magenta and 94% yellow.
The cover 22 is provided to restrict light escaping from the housing 12 without passing through the LCD 18 and filters 22 and to provide a uniform boundaries for each shutter sector.
<Desc/Clms Page number 5>
The LCD 18 is controllable by a processor (not shown) in a known manner.

Claims (16)

  1. Claims 1. A lighting assembly comprising a housing having a light source, a liquid crystal display and a plurality of coloured filters interposed in the path of light from the light source, wherein the liquid crystal display includes a plurality of cells, each cell being selectively controllable between an open position, in which light may pass through the liquid crystal display, and a closed position, in which light may not pass through the liquid crystal display, to enable the output of light from the lighting assembly to be selectively altered.
  2. 2. A lighting assembly as claimed in claim 1, in which the liquid crystal display is part of a shutter arrangement, wherein the liquid crystal display is disposed between the plurality of coloured filters and a cover on the outer side of the liquid crystal display.
  3. 3. A lighting assembly as claimed claim 1 or 2, in which the liquid crystal display consists of a plurality of shutter sectors, each shutter sector having a plurality of the selectively controllable cells.
  4. 4. A lighting assembly as claimed in any one of claims 1 to 3, in which the liquid crystal display is polygonal.
  5. 5. A lighting assembly as claimed in any preceding claim, in which the coloured filters are arranged at radially spaced intervals on the inner surface of the liquid crystal display.
  6. 6. A lighting assembly as claimed in any preceding claim, in which the coloured filters consist of one or more groups of three different coloured filters.
  7. 7. A lighting assembly as claimed in claim 6, in which the different coloured filters are cyan, magenta and yellow.
    <Desc/Clms Page number 7>
  8. 8. A lighting assembly as claimed in any preceding claim, in which the cells are directly actuatable.
  9. 9. A lighting assembly as claimed in any preceding claim, in which the light source has a uniform light distribution.
  10. 10. A lighting assembly as claimed in any preceding claim, in which the light source is a compact fluorescent lamp.
  11. 11. A lighting assembly as claimed in any preceding claim, in which the light source is a low- pressure lamp.
  12. 12. A lighting assembly as claimed in any preceding claim, in which the internal walls of the housing are reflective, for at least partially reflecting light emitted from the light source to an output end of the housing.
  13. 13. A lighting assembly as claimed in any preceding claim, in which the housing is conical.
  14. 14. A method of selectively controlling the output from a light source using the lighting assembly as described in any preceding claim.
  15. 15. A lighting assembly as hereinbefore described with reference to the accompanying drawings.
  16. 16. A method of selectively controlling the output colour from a light source as hereinbefore described with reference to the accompanying drawings.
GB0200481A 2002-01-10 2002-01-10 Lighting assembly Withdrawn GB2384101A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB0200481A GB2384101A (en) 2002-01-10 2002-01-10 Lighting assembly

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB0200481A GB2384101A (en) 2002-01-10 2002-01-10 Lighting assembly

Publications (2)

Publication Number Publication Date
GB0200481D0 GB0200481D0 (en) 2002-02-27
GB2384101A true GB2384101A (en) 2003-07-16

Family

ID=9928849

Family Applications (1)

Application Number Title Priority Date Filing Date
GB0200481A Withdrawn GB2384101A (en) 2002-01-10 2002-01-10 Lighting assembly

Country Status (1)

Country Link
GB (1) GB2384101A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2007057830A1 (en) * 2005-11-21 2007-05-24 Philips Intellectual Property & Standards Gmbh Optical system

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4396251A (en) * 1979-03-05 1983-08-02 Hitachi, Ltd. Pleochroic color display device
EP0237707A2 (en) * 1986-03-20 1987-09-23 VDO Adolf Schindling AG Display device
WO1993008558A1 (en) * 1991-10-24 1993-04-29 Stephen Weinreich Color display apparatus

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4396251A (en) * 1979-03-05 1983-08-02 Hitachi, Ltd. Pleochroic color display device
EP0237707A2 (en) * 1986-03-20 1987-09-23 VDO Adolf Schindling AG Display device
WO1993008558A1 (en) * 1991-10-24 1993-04-29 Stephen Weinreich Color display apparatus

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2007057830A1 (en) * 2005-11-21 2007-05-24 Philips Intellectual Property & Standards Gmbh Optical system

Also Published As

Publication number Publication date
GB0200481D0 (en) 2002-02-27

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