WO2018083066A1

WO2018083066A1 - Controlling a light source in dependence on a measured property

Info

Publication number: WO2018083066A1
Application number: PCT/EP2017/077800
Authority: WO
Inventors: Ties Van Bommel; Rifat Ata Mustafa Hikmet
Original assignee: Philips Lighting Holding B.V.
Priority date: 2016-11-03
Filing date: 2017-10-30
Publication date: 2018-05-11

Abstract

A lighting system comprises: one or more light sensors (57) positioned at a first side of an at least partly transparent textile surface (3); one or more light sources (5-7) positioned at a second side of said textile surface (3), said textile surface (3) being at least partly illuminated by said one or more light sources (5-7), said second side being opposite said first side, wherein said one or more light sources form a plurality of display elements; and a light controller (1) configured to receive one or more measured properties of one or more light transmissions (15-17) from said one or more light sensors (57), and to control said one or more light sources (5-7) in dependence on said one or more measured properties. The light controller is configured to select a subset of said plurality of display elements in dependence on said one or more measured properties of said one or more light transmissions and to control said one or more light sources to display a text and/or a graphic in said selected subset of display elements.

Description

CONTROLLING A LIGHT SOURCE IN DEPENDENCE ON A MEASURED PROPERTY

FIELD OF THE INVENTION

The invention relates to a light controller and an apparatus comprising a light controller.

The invention further relates to a method of controlling one or more light sources.

The invention also relates to a computer program product enabling a computer system to perform such a method.

BACKGROUND OF THE INVENTION

WO2010/052606 A2 discloses a lighting arrangement comprising a carpet structure and a control unit. The carpet structure comprises a carpet back lighting system and a light transmissive carpet unit. The control unit is configured to generate, in response to one or more input signals, one or more output signals to control the light generated by the light sources of the carpet back lighting. The input signals may be a direction of a person and the light generated by the light sources may be in the form of a light pattern indicative of this direction, for example.

WO2010/052606 A2 does not take into account that different textile surfaces, or different areas of a patterned textile surface, may have different properties which absorb the light transmitted through them differently.

JP 2008/264430 A relates to a target color emphasizing system wherein a color of an illumi-nating light, which may illuminate clothing, is corrected in accordance with a detection result of an ambient light detection part and luminance of the illuminating light is adjusted in ac-cordance with the detection result of the color illuminance detection part.

US 2013/0320860 Al discloses vase-shaped device comprising an output unit configured to output a signal as controlled; a first light-emitting device configured to illuminate a flower, for example a nylon or silk flower, put in the vase-shaped device; a color sensor configured to obtain data on a color of the flower by using light emitted by the first light-emitting device and reflected from the flower; a determination unit configured to determine the color of the flower based on the data obtained by the color sensor; and control processing unit config-ured to generate the signal to be outputted from the output unit, according to a result of the determination by the determination unit.

US 2012/0139956 Al discloses an apparatus for providing a viewer with a blend of displayed and reflected content. The apparatus includes an emissive display device with a display screen operable providing digital content. The emissive display device includes a light source selectively articulating and transmitting light through the display screen at a particular illumina-tion level to display digital content such as text and graphics. The apparatus includes a the-matic overlay positioned over the display screen with a front surface configured to provide diffuse reflection of light striking the front surface from a viewer space such that the front sur-face appears substantially opaque to the viewer and the viewer cannot see the display screen when the light source is inactive or at low brightness. When the light source is in active mode, the displayed content is visible as emissive display content concurrently with the diffuse re-flection content but the display screen remains hidden from view.

SUMMARY OF THE INVENTION

It is a first object of the invention to provide a light controller for use with a luminous textile, which takes into account at least one property of the textile surface.

It is a second object of the invention to provide a method of controlling one or more light sources for use with a luminous textile, which takes into account at least one property of the textile surface.

In a first aspect of the invention, the object is achieved by a lighting system comprising:

- one or more light sensors positioned at a first side of an at least partly transparent textile surface,

- one or more light sources positioned at a second side of said textile surface, said textile surface being at least partly illuminated by said one or more light sources, said second side being opposite said first side, wherein said one or more light sources form a plurality of display elements, and

- a light controller configured to receive one or more measured properties of one or more light transmissions from said one or more light sensors, and to control said one or more light sources in dependence on said one or more measured properties, wherein said light controller is configured to select a subset of said plurality of display elements in dependence on said one or more measured properties of said one or more light transmissions and to control said one or more light sources to display a text and/or a graphic in said selected subset of display elements.

The inventors have recognized that by measuring the light illuminating the textile surface at the side from which persons will normally view the textile surface and automatically controlling the light sources illuminating the textile surface based on this measurement, at least one property of the textile surface can be taken into account, e.g.

amplified or compensated for. The invention may be used, for example, to prevent that colored light of a color which would be absorbed by the textile surface is used, which would decrease the efficiency of the (e.g. carpet) lighting.

Textile is a flexible material consisting of a network of natural or artificial fibres (yarn or thread). Yarn is produced by spinning raw fibres of wool, flax, cotton, or other material to produce long strands. Textiles are formed by weaving, knitting, crocheting, knotting, or felting.

Said textile surface may be part of a floor cover, a wall cover, a ceiling cover, a furniture cover or a piece of clothing. A floor cover may comprise a carpet or carpet tile, for example. A wall cover may comprise a wall paper, a wall tile, or a curtain, for example. A furniture cover may comprise a seat cover, for example.

Said light controller may be configured to receive one or more first measured properties and one or more second measured properties from said one or more light sensors, to control a first subset of said one or more light sources in dependence on said one or more first measured properties, and to control a second subset of said one or more light sources in dependence on said one or more second measured properties.

When the textile surface is a patterned, e.g. a color patterned, textile surface, this allows one or more light sources illuminating a first area to be controlled independently from one or more light sources illuminating a second area, e.g. to use the light sources to compensate for the differences in light absorption and create uniform light output. This is beneficial, because when a patterned colored surface is used, light is absorbed differently in different areas leading to color and/or intensity variations. For example, when white light is used below a carpet, certain wavelengths are absorbed more than others, leading to the colored appearance of the white light. Said light controller may be configured to determine one or more properties of said textile surface from said one or more measured properties of said one or more light transmissions and to control one or more settings of said one or more light sources to amplify or compensate for said one or more properties of said textile surface. Amplifying said one or more properties of said textile surface may be used to save energy. Compensating for said one or more properties of said textile surface may be used to ensure uniform light output. Determining a property of the textile surface may comprise determining a change in a light transmission when it passes through the textile surface, for example. A property of a textile surface may comprise one or more colors that are identified as being absorbed significantly by the textile surface, a degree of absorption or transmission of one or more colors by the textile surface and/or one or more colors that are identified as being absorbed insignificantly by the textile surface.

Said light controller may be configured to determine one or more dominant colors from said one or more measured properties of said one or more light transmissions and/or to receive one or more dominant colors determined from said one or more measured properties of said one or more light transmissions and to control said one or more light sources to decrease intensity of colors other than said one or more dominant colors in said illumination provided by said one or more light sources. This saves light and therefore energy that would otherwise would not be used efficiently.

Said light controller may be configured to determine and/or receive one or more first dominant colors and one or more second dominant colors, to control a first subset of said one or more light sources to decrease intensity of colors other than said one or more first dominant colors in illumination provided by said first subset of said one or more light sources and to control a second subset of said one or more light sources to decrease intensity of colors other than said one or more second dominant colors in illumination provided by said second subset of said one or more light sources. For example, a textile surface consisting of patterned blue and red areas may be illuminated from below with matching light transmissions so that the blue areas do not have red illumination, while the red areas do not have blue illumination in order to save light.

Said one or more measured properties of said one or more light transmissions may comprise a first measured property and a second measured property and said light controller may be configured to determine or receive a target average or median of said first measured property and said second measured property, to control a first subset of said one or more light sources in dependence on a difference between said first measured property and said target average or median and to control a second subset of said one or more light sources in dependence on a difference between said second measured property and said target average or median. This may be used to prevent uniform illumination from appearing nonuniform on a colored patterned textile surface. For example, when uniform light output is desired from the whole surface, then blue areas may be illuminated with more red light and the red areas may be illuminated with more blue light.

Said light controller may be configured to control said one or more light sources to use a first light spectrum to obtain a desired color, to control said one or more light sources (5-7) to use a second light spectrum different from said first light spectrum to obtain said desired color, and to calculate and select a light spectrum from said first and second light spectrum which has the lowest light loss, i.e. a higher transmission and thus lower absorption and reflection, , and to control said one or more light sources (5-7) to use the light spectrum which has the lowest light loss. This saves energy that would otherwise would not be used efficiently.

Said one or more light sources form a plurality of display elements and said light controller is configured to select a subset of said plurality of display elements in dependence on said one or more measured properties of said one or more light transmissions, and to control said one or more light sources to display a text and/or a graphic in said selected subset of display elements. In this way, the light controller may calculate the most energy efficient location for displaying the text and/or the graphic.

Said one or more measured properties of said one or more light transmissions may comprise at least one of: a light spectrum, a light wavelength, a color point, and a color temperature. Said light controller may be configured to control an intensity, a color and/or a light spectrum of said one or more light sources.

Moreover, an apparatus which comprises the light controller described herein is provided. Said apparatus may comprise said one or more light sources and/or said textile surface.

In a second aspect of the invention, the object is achieved by a method of controlling one or more light sources, said one or more light sensors being positioned at a first side of an at least partly transparent textile surface, said textile surface being at least partly illuminated by one or more light sources positioned at a second side of said textile surface, said second side being opposite said first side, wherein said one or more light sources form a plurality of display elements, the method comprising:

- receiving one or more measured properties of one or more light transmissions from one or more light sensors,; and

- selecting a subset of said plurality of display elements in dependence on said one or more measured properties of said one or more light transmissions,

- controlling said one or more light sources to display a text and/or a graphic in said selected subset of display elements.

. The method may be implemented in hardware and/or software. The method may be carried out by the light controller, for example.

Moreover, a computer program for carrying out the methods described herein, as well as a non-transitory computer readable storage-medium storing the computer program are provided. A computer program may, for example, be downloaded by or uploaded to an existing device or be stored upon manufacturing of these systems.

A non-transitory computer-readable storage medium stores at least one software code portion, the software code portion, when executed or processed by a computer, being configured to perform executable operations comprising: receiving one or more measured properties of one or more light transmissions from one or more light sensors, said one or more light sensors being positioned at a first side of an at least partly transparent textile surface, said textile surface being at least partly illuminated by one or more light sources positioned at a second side of said textile surface, said second side being opposite said first side, and controlling said one or more light sources in dependence on said one or more measured properties.

As will be appreciated by one skilled in the art, aspects of the present invention may be embodied as a device, a method or a computer program product.

Accordingly, aspects of the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, micro- code, etc.) or an embodiment combining software and hardware aspects that may all generally be referred to herein as a "circuit", "module" or "system." Functions described in this disclosure may be implemented as an algorithm executed by a processor/microprocessor of a computer. Furthermore, aspects of the present invention may take the form of a computer program product embodied in one or more computer readable medium(s) having computer readable program code embodied, e.g., stored, thereon.

Any combination of one or more computer readable medium(s) may be utilized. The computer readable medium may be a computer readable signal medium or a computer readable storage medium. A computer readable storage medium may be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of a computer readable storage medium may include, but are not limited to, the following: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In the context of the present invention, a computer readable storage medium may be any tangible medium that can contain, or store, a program for use by or in connection with an instruction execution system, apparatus, or device.

A computer readable signal medium may include a propagated data signal with computer readable program code embodied therein, for example, in baseband or as part of a carrier wave. Such a propagated signal may take any of a variety of forms, including, but not limited to, electro-magnetic, optical, or any suitable combination thereof. A computer readable signal medium may be any computer readable medium that is not a computer readable storage medium and that can communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device.

Program code embodied on a computer readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber, cable, RF, etc., or any suitable combination of the foregoing. Computer program code for carrying out operations for aspects of the present invention may be written in any

combination of one or more programming languages, including an object oriented programming language such as Java(TM), Smalltalk, C++ or the like and conventional procedural programming languages, such as the "C" programming language or similar programming languages. The program code may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer, or entirely on the remote computer or server. In the latter scenario, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider).

Aspects of the present invention are described below with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the present invention. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor, in particular a microprocessor or a central processing unit (CPU), of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer, other programmable data processing apparatus, or other devices create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer readable medium that can direct a computer, other programmable data processing apparatus, or other devices to function in a particular manner, such that the instructions stored in the computer readable medium produce an article of manufacture including instructions which implement the function/act specified in the flowchart and/or block diagram block or blocks.

The computer program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other devices to cause a series of operational steps to be performed on the computer, other programmable apparatus or other devices to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide processes for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.

The flowchart and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of devices, methods and computer program products according to various embodiments of the present nvention. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in some alternative implementations, the functions noted in the blocks may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustrations, and combinations of blocks in the block diagrams and/or flowchart illustrations, can be implemented by special purpose hardware-based systems that perform the specified functions or acts, or combinations of special purpose hardware and computer instructions. BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects of the invention are apparent from and will be further elucidated, by way of example, with reference to the drawings, in which:

Fig. 1 is a block diagram of a first embodiment of a lighting system comprising an embodiment of the light controller;

Fig. 2 is a block diagram of a second embodiment of the lighting system; Fig. 3 is a block diagram of a third embodiment of the lighting system;

Fig. 4 is a block diagram of a fourth embodiment of the lighting system; Fig. 5 is a block diagram of a fifth embodiment of the lighting system;

Fig. 6 illustrates a first light source being switched on in order to perform a measurement;

Fig. 7 illustrates a second light source being switched on in order to perform a measurement;

Fig. 8 illustrates a third light source being switched on in order to perform a measurement;

Fig. 9 illustrates a remote measurement of a light transmission; Fig. 10 illustrates a near measurement of a light transmission;

Fig. 1 1 depicts a first example of a color patterned textile surface through which a text is displayed;

Fig. 12 depicts a second example of a color patterned textile surface through which a text is displayed;

Fig. 13 is a flow diagram of the method of controlling one or more light sources; and

Fig. 14 is a block diagram of an exemplary data processing system for performing the method.

Corresponding elements in the drawings are denoted by the same reference numeral. DETAILED DESCRIPTION OF THE DRAWINGS

Fig. l shows a first embodiment of the apparatus, an apparatus 19, and a first embodiment of the light controller, a light controller 1. The light controller 1 is configured to receive one or more measured properties of light transmissions 15-17 from one or more light sensors, the one or more light sensors being positioned at a first side of an at least partly transparent textile surface 3, the textile surface 3 being at least partly illuminated by light sources 5-7 positioned at a second side of the textile surface 3, the second side being opposite the first side, and to control the light sources 5-7 in dependence on the one or more measured properties.

The light source 5 transmits a light transmission 11. Some of the frequencies of the light transmission 11 may be absorbed by the surface 3. Light transmission 15 is the part of the light transmission 11 that is able to pass through the textile surface 3. The light source 6 transmits a light transmission 12. Some of the frequencies of the light transmission 12 may be absorbed by the textile surface 3. Light transmission 16 is the part of the light transmission 12 that is able to pass through the textile surface 3. The light source 7 transmits a light transmission 13. Some of the frequencies of the light transmission 13 may be absorbed by the textile surface 3. Light transmission 17 is the part of the light transmission 13 that is able to pass through the textile surface 3. For example: the transmission of first light of the light source 6 through a first part of the textile surface 3 is 50%, while the transmission of second light of the light source 7 through a second part of the textile surface 3 is 70%. The first light and second light are of the same color, e.g. blue. The apparatus 19 may measure and analyze the light transmissions 15 and 16 and decide to power the light source 7 and not the light source 6, because the transmission of the second light though through the second part of the textile surface 3 is higher than the transmission of the first light through the first part of the textile surface 3.

The one or more measured properties of the light transmissions 15-17 may comprise a light spectrum, a light wavelength, a color point and/or a color temperature, for example. The light controller 1 may be configured to control an intensity, a color and/or a light spectrum of the light sources 5-7. The textile surface 3 may comprise a carpet, a carpet tile, a wall paper or a wall tile, for example.

The apparatus 19 may comprise a communication interface for receiving the one or more measured properties of light transmissions 15-17 from the one or more light sensors (either directly or indirectly). The one or more measured properties may be received via a wire or wireless. The communication interface of the apparatus 19 may use WiFi, Bluetooth and/or Zigbee to receive the one or more measured properties, for example.

The light sources 5-7 are preferably solid state lighting. The light sources 5-7 may be semiconductor LEDs, organic LEDs or polymer LEDs, for example. The LEDs are preferably colored LEDs. For example, light source 5 may be a red LED, light source 6 may be a green LED and light source 7 may be a blue LED. The light controller 1 may comprise one or more general-purpose processors and/or one or more application-specific processors. The invention may be implemented using a computer program running on one or more processors. The apparatus 19 may comprise other components typical for a controller device, e.g. a power supply. The one or more light sensors may comprise one or more diodes, for example.

The light controller 1 may be configured to determine one or more properties of the textile surface 3 from the one or more measured properties of the light transmissions 15-17 and to control one or more settings of the light sources 5-7 to amplify or compensate for the one or more properties of the textile surface 3.

If the textile surface 3 has a colored pattern, preferably a first subset of the light sources 5-7 is used to illuminate a first area of the textile surface 3 and a second subset of the light sources 5-7 is used to illuminate a second area of the textile surface 3. The one or more light sensors may then be used to measure one or more first properties of a light transmission emanating from the first area and one or more second properties of a light transmission emanating from the second area. If the textile surface 3 has a colored pattern, the light controller 1 is preferably configured to receive the one or more first measured properties and the one or more second measured properties from the one or more light sensors, to control the first subset of the light sources 5-7 in dependence on the one or more first measured properties, and to control a second subset of the light sources 5-7 in dependence on the one or more second measured properties.

In order to amplify the one or more properties of the textile surface 3, the light controller 1 may be configured to determine one or more dominant colors from the one or more measured properties of the light transmissions 15-17 and/or to receive one or more dominant colors determined from the one or more measured properties of the light transmissions 15-17 and to control the light sources 5-7 to decrease (some or all) colors other than the one or more dominant colors in the illumination provided by the light sources 5-7. In this way, energy is saved. The one or more dominant colors may be determined by the light controller 1 itself and/or by one or more other devices, e.g. the one or more light sensors.

Another way of saving energy is to configure the light controller 1 to control the light sources 5-7 to use a first light spectrum to obtain a desired color instead of a second light spectrum suitable for obtaining the desired color with a higher light loss. For example, colored LEDs may be used with a tunable spectrum such that it has at least two settings with different spectra, but the same visual appearance to a person (i.e. the same color point). Dependent on the measured transmission properties, the light controller 1, e.g. a computer program running on the light controller 1 , may calculate and select the spectrum with the lowest light loss and adapt the light of the selected light source such that a desired color point is obtained. A user interface of the lighting system may allow a user, e.g. using a mobile phone or tablet, to overrule the calculations of the light controller 1.

If the textile surface 3 has a colored pattern, the light controller 1 may be configured to determine and/or receive one or more first dominant colors (one or more of the light transmissions 15-17) and one or more second dominant colors (one or more of the light transmissions 15-17), to control a first subset of the light sources 5-7 to decrease (some or all) colors other than the one or more first dominant colors in illumination provided by the first subset of the light sources 5-7 and to control a second subset of the light sources 5-7 to decrease (some or all) colors other than the one or more second dominant colors in illumination provided by the second subset of the light sources 5-7. The one or more first and second dominant colors may be determined by the light controller 1 itself and/or by one or more other devices, e.g. the one or more light sensors.

In order to compensate for the one or more properties of the textile surface 3, in particular for differences between properties of different areas of the textile surface 3, e.g. if the textile surface 3 has a colored pattern, the light controller 1 may be configured to determine or receive a target average or median of a first measured property of a light transmission emanating from the first area and a second measured property of a light transmission emanating from the second area, to control a first subset of the light sources 5-7 in dependence on a difference between the first measured property and the target average or median and to control a second subset of the light sources 5-7 in dependence on a difference between the second measured property and the target average or median.

In the first embodiment of the lighting system shown Fig. l, the apparatus 19 comprises the light controller 1, but does not comprise any of the light sources 5-7 or the textile surface 3. The light sources 5-7 are part of a light assembly 21 separate from the textile surface 3. In a second embodiment of the lighting system shown in Fig.2, an apparatus 29 comprises both the light controller 1 and the light sources 5-7, but this apparatus does not comprise the textile surface 3.

In a third embodiment of the lighting system shown in Fig.3, a luminous textile 31 comprises the light sources 5-7 as well as the textile surface 3, but not the light controller 1. Like in the first embodiment shown in Fig.1 , the light controller 1 is part of the separate apparatus 19. In a fourth embodiment of the lighting system shown in Fig. 4, a luminous textile 49 comprises the light sources 5-7 as well as the textile surface 3 and the light controller 1. The size of the light controller 1 of this apparatus may be adapted to the dimensions of the textile surface 3.

In a fifth embodiment of the lighting system shown in Fig. 5, a light controller 53 is part of a mobile device 51. The light controller 53 of this apparatus communicates with a further controller 61 , which is part of a controller device 59. The further controller 61 forwards control instructions from the light controller 53 to the light sources 5-7. A luminous textile 31 comprises the light sources 5-7 as well as the textile surface 3. In an alternative embodiment, the further controller 61 is part of the luminous textile 3 1. The mobile device 51 may be a mobile phone, a tablet or a camera, for example. The mobile device 51 further comprises a light sensor 57, which is used by the light controller 53 in the manner described in previous paragraphs. The light sensor 57 may be a photo diode or a camera of the mobile device 51, for example. The light controller 53 may be implemented on a general purpose or application-specific processor, which may also be used to implement other functions.

In order to accurately measure how a single light source's light transmission is affected by the textile surface 3, the light controller 1 may switch on the light sources in sequence so that during each measurement only one light source is switched on and measurements are performed for each light source. When multiple light sources cannot be or are not independently controlled, these multiple lights sources may be switched on together and the corresponding measurement(s) will apply to the group comprising the multiple light sources.

The light controller 1 may be able to instruct the one or more light sensors, or a particular one of a plurality of light sensors, to perform a measurement, for example.

Alternatively, the light controller 1 may be configured to receive a continuous stream of measurements from the one or more light sensors and to associate the correct measurement(s) with the corresponding light source, for example.

In an ideal configuration, each light source and group of jointly controlled light sources mostly illuminates one area of the textile surface 3. If a light source or group of jointly controlled light sources contributes significantly to the illumination of multiple (differently colored) areas of the textile surface 3, the light controller 1 may be configured to control the light source (group) with a setting that is optimal for only a subset of the multiple areas or with a setting that is an average of the optimal settings for each of the multiple areas, for example.

Fig. 6 illustrates a first stage in which only the light source 5 is switched on so that the one or more light sensors can measure one or more properties of the light transmission 15. Fig. 7 illustrates a second stage in which only the light source 6 is switched on so that the one or more light sensors can measure one or more properties of the light transmission 16. Fig. 8 illustrates a third stage in which only the light source 7 is switched on so that the one or more light sensors can measure one or more properties of the light transmission 17.

In order to accurately measure a light source's light transmission, the one or more light sensors are preferably shielded from receiving other light transmissions. In this case, a single light sensor may need to be moved in each stage of the measurements or multiple light sensors may need to be used. Fig. 9 shows a measurement device 71 comprising the light sensor 57 in a remote configuration, i.e. farther from the textile surface 3. The measurements may be better when the proximity configuration shown in Fig. 10 is used. In this configuration, the measurement device 71 is positioned near the textile surface 3.

Fig. 1 1 depicts a first example of a colored patterned textile surface through which a text is displayed. The colored patterned textile surface comprises nine areas 81 -89. Behind the nine areas 81-89, a plurality of light sources forms a plurality of display elements for displaying a text and/or graphic. In an embodiment of the light controller, the light controller 1 is configured to select a subset of the plurality of display elements in dependence on the one or more measured properties of the one or more light transmissions and to control the plurality of light sources to display a text and/or a graphic in the selected subset of display elements.

In the first example of the colored patterned textile surface, areas 81, 83, 85, 87 and 89 of the textile surface 3 absorb a relatively large portion of light and areas 82, 84, 86 and 88 of the textile surface 3 absorb a relatively small portion of light. In order to benefit efficiency, the light sources behind area 84-86 are selected to display a, e.g. blue, text "TXT", because two of these areas (84 and 86) absorb a relatively small portion of light.

In the second example of the colored patterned textile surface depicted in Fig. 12, areas 92, 94, 96 and 98 of the textile surface 3 absorb a relatively large portion of light and areas 91, 93, 95, 97 and 99 of the textile surface 3 absorb a relatively small portion of light. In order to benefit efficiency, the light sources behind areas 91 -93 are selected to display a, e.g. blue, text "TXT", because two of these areas (91 and 93) absorb a relatively small portion of light.

The method of controlling one or more light sources comprises at least a step 11 1 and a step 113, see Fig. 13. Step 11 1 comprises receiving one or more measured properties of one or more light transmissions from one or more light sensors. The one or more light sensors are positioned at a first side of an at least partly transparent textile surface. The textile surface is at least partly illuminated by one or more light sources positioned at a second side of the textile surface opposite the first side. Step 113 comprises controlling the one or more light sources in dependence on the one or more measured properties. The method may be performed by the light controller described in relation to Figs. 1 to 12, for example.

Fig. 14 depicts a block diagram illustrating an exemplary data processing system that may perform the method as described with reference to Fig. 13.

As shown in Fig. 14, the data processing system 300 may include at least one processor 302 coupled to memory elements 304 through a system bus 306. As such, the data processing system may store program code within memory elements 304. Further, the processor 302 may execute the program code accessed from the memory elements 304 via a system bus 306. In one aspect, the data processing system may be implemented as a computer that is suitable for storing and/or executing program code. It should be appreciated, however, that the data processing system 300 may be implemented in the form of any system including a processor and a memory that is capable of performing the functions described within this specification.

The memory elements 304 may include one or more physical memory devices such as, for example, local memory 308 and one or more bulk storage devices 310. The local memory may refer to random access memory or other non-persistent memory device(s) generally used during actual execution of the program code. A bulk storage device may be implemented as a hard drive or other persistent data storage device. The processing system 300 may also include one or more cache memories (not shown) that provide temporary storage of at least some program code in order to reduce the number of times program code must be retrieved from the bulk storage device 310 during execution.

Input/output (I/O) devices depicted as an input device 312 and an output device 314 optionally can be coupled to the data processing system. Examples of input devices may include, but are not limited to, a keyboard, a pointing device such as a mouse, or the like. Examples of output devices may include, but are not limited to, a monitor or a display, speakers, or the like. Input and/or output devices may be coupled to the data processing system either directly or through intervening I O controllers.

In an embodiment, the input and the output devices may be implemented as a combined input/output device (illustrated in Fig. 14 with a dashed line surrounding the input device 312 and the output device 314). An example of such a combined device is a touch sensitive display, also sometimes referred to as a "touch screen display" or simply "touch screen". In such an embodiment, input to the device may be provided by a movement of a physical object, such as e.g. a stylus or a finger of a user, on or near the touch screen display.

A network adapter 316 may also be coupled to the data processing system to enable it to become coupled to other systems, computer systems, remote network devices, and/or remote storage devices through intervening private or public networks. The network adapter may comprise a data receiver for receiving data that is transmitted by said systems, devices and/or networks to the data processing system 300, and a data transmitter for transmitting data from the data processing system 300 to said systems, devices and/or networks. Modems, cable modems, and Ethernet cards are examples of different types of network adapter that may be used with the data processing system 300.

As pictured in Fig. 14, the memory elements 304 may store an application 318. In various embodiments, the application 318 may be stored in the local memory 308, the one or more bulk storage devices 310, or separate from the local memory and the bulk storage devices. It should be appreciated that the data processing system 300 may further execute an operating system (not shown in Fig. 14) that can facilitate execution of the application 318. The application 318, being implemented in the form of executable program code, can be executed by the data processing system 300, e.g., by the processor 302.

Responsive to executing the application, the data processing system 300 may be configured to perform one or more operations or method steps described herein.

Various embodiments of the invention may be implemented as a program product for use with a computer system, where the program(s) of the program product define functions of the embodiments (including the methods described herein). In one embodiment, the program(s) can be contained on a variety of non-transitory computer-readable storage media, where, as used herein, the expression "non-transitory computer readable storage media" comprises all computer-readable media, with the sole exception being a transitory, propagating signal. In another embodiment, the program(s) can be contained on a variety of transitory computer-readable storage media. Illustrative computer-readable storage media include, but are not limited to: (i) non-writable storage media (e.g., read-only memory devices within a computer such as CD-ROM disks readable by a CD-ROM drive, ROM chips or any type of solid-state non-volatile semiconductor memory) on which information is permanently stored; and (ii) writable storage media (e.g., flash memory, floppy disks within a diskette drive or hard-disk drive or any type of solid-state random-access semiconductor memory) on which alterable information is stored. The computer program may be run on the processor 302 described herein.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/ or groups thereof.

The corresponding structures, materials, acts, and equivalents of all means or step plus function elements in the claims below are intended to include any structure, material, or act for performing the function in combination with other claimed elements as specifically claimed. The description of embodiments of the present invention has been presented for purposes of illustration, but is not intended to be exhaustive or limited to the implementations in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the present invention. The embodiments were chosen and described in order to best explain the principles and some practical applications of the present invention, and to enable others of ordinary skill in the art to understand the present invention for various embodiments with various modifications as are suited to the particular use contemplated.

Claims

CLAIMS:

1. A lighting system comprising:

- one or more light sensors (57) positioned at a first side of an at least partly transparent textile surface (3),

- one or more light sources (5-7) positioned at a second side of said textile surface (3), said textile surface (3) being at least partly illuminated by said one or more light sources (5-7), said second side being opposite said first side, wherein said one or more light sources form a plurality of display elements, and

- a light controller (1) configured to receive one or more measured properties of one or more light transmissions (15-17) from said one or more light sensors (57), and to control said one or more light sources (5-7) in dependence on said one or more measured properties,

wherein said light controller is configured to select a subset of said plurality of display elements in dependence on said one or more measured properties of said one or more light transmissions and to control said one or more light sources to display a text and/or a graphic in said selected subset of display elements.

2. A light controller (1) as claimed in claim 1, wherein said light controller (1) is configured to receive one or more first measured properties and one or more second measured properties from said one or more light sensors (57), to control a first subset of said one or more light sources (5-7) in dependence on said one or more first measured properties, and to control a second subset of said one or more light sources (5-7) in dependence on said one or more second measured properties.

3. A light controller (1) as claimed in claim 1 or 2, wherein said light controller (1) is configured to determine one or more properties of said textile surface (3) from said one or more measured properties of said one or more light transmissions (15-17) and to control one or more settings of said one or more light sources (5-7) to amplify or compensate for said one or more properties of said textile surface (3).

4. A light controller (1) as claimed in any one of the preceding claims, wherein said light controller (1) is configured to determine one or more dominant colors from said one or more measured properties of said one or more light transmissions (15-17) and/or to receive one or more dominant colors determined from said one or more measured properties of said one or more light transmissions (15-17) and to control said one or more light sources (5-7) to decrease intensity of colors other than said one or more dominant colors in said illumination provided by said one or more light sources (5-7).

5. A light controller (1) as claimed in claim 5, wherein said light controller (1) is configured to determine and/or receive one or more first dominant colors and one or more second dominant colors, to control a first subset of said one or more light sources (5-7) to decrease intensity of colors other than said one or more first dominant colors in illumination provided by said first subset of said one or more light sources (5-7) and to control a second subset of said one or more light sources (5-7) to decrease intensity of colors other than said one or more second dominant colors in illumination provided by said second subset of said one or more light sources (5-7).

6. A light controller (1) as claimed in any one of the preceding claims, wherein said one or more measured properties of said one or more light transmissions (15-17) comprise a first measured property and a second measured property and said light controller (1) is configured to determine or receive a target average or median of said first measured property and said second measured property, to control a first subset of said one or more light sources (5-7) in dependence on a difference between said first measured property and said target average or median and to control a second subset of said one or more light sources (5- 7) in dependence on a difference between said second measured property and said target average or median.

7. A light controller (1) as claimed in any one of the preceding claims, wherein said light controller (1) is configured to control said one or more light sources (5-7) to use a first light spectrum to obtain a desired color, to control said one or more light sources (5-7) to use a second light spectrum different from said first light spectrum to obtain said desired color, and to calculate and select a light spectrum from said first and second light spectrum which has the lowest light loss, and to control said one or more light sources (5-7) to use the light spectrum which has the lowest light loss.

8. A light controller (1) as claimed in in any one of the preceding claims, wherein said one or more measured properties of said one or more light transmissions (15-17) comprise at least one of: a light spectrum, a light wavelength, a color point, and a color temperature.

9. A light controller (1) as claimed in any one of the preceding claims, wherein said light controller (1) is configured to control an intensity, a color and/or a light spectrum of said one or more light sources (5-7).

10. A light controller (1) as claimed in any one of the preceding claims, wherein said textile surface (3) is part of a floor cover, a wall cover, a ceiling cover, a furniture cover or a piece of clothing.

1 1. A method of controlling one or more light sources, said one or more light sensors being positioned at a first side of an at least partly transparent textile surface, said textile surface being at least partly illuminated by one or more light sources positioned at a second side of said textile surface, said second side being opposite said first side, wherein said one or more light sources form a plurality of display elements, the method comprising:

- receiving (11 1) one or more measured properties of one or more light transmissions from one or more light sensors,; and

- controlling (113) said one or more light sources to display a text and/or a graphic in said selected subset of display elements.

12. A computer program or suite of computer programs comprising at least one software code portion or a computer program product storing at least one software code portion, the software code portion, when run on a computer system, being configured for performing the method of claim 1 1.