WO2010046811A1 - Procédé et dispositif électronique pour améliorer l’uniformité optique de sources d’éclairage à dalles oled - Google Patents

Procédé et dispositif électronique pour améliorer l’uniformité optique de sources d’éclairage à dalles oled Download PDF

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Publication number
WO2010046811A1
WO2010046811A1 PCT/IB2009/054529 IB2009054529W WO2010046811A1 WO 2010046811 A1 WO2010046811 A1 WO 2010046811A1 IB 2009054529 W IB2009054529 W IB 2009054529W WO 2010046811 A1 WO2010046811 A1 WO 2010046811A1
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WO
WIPO (PCT)
Prior art keywords
oled
tiles
power
electronic device
optical properties
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Application number
PCT/IB2009/054529
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English (en)
Inventor
Dirk Hente
Joseph H. A. M. Jacobs
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Philips Intellectual Property & Standards Gmbh
Koninklijke Philips Electronics N. V.
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Application filed by Philips Intellectual Property & Standards Gmbh, Koninklijke Philips Electronics N. V. filed Critical Philips Intellectual Property & Standards Gmbh
Publication of WO2010046811A1 publication Critical patent/WO2010046811A1/fr

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Classifications

    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/22—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources
    • G09G3/30—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using electroluminescent panels
    • G09G3/32—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using electroluminescent panels semiconductive, e.g. using light-emitting diodes [LED]
    • G09G3/3208—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using electroluminescent panels semiconductive, e.g. using light-emitting diodes [LED] organic, e.g. using organic light-emitting diodes [OLED]
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
    • H05B45/60—Circuit arrangements for operating LEDs comprising organic material, e.g. for operating organic light-emitting diodes [OLED] or polymer light-emitting diodes [PLED]
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2320/00—Control of display operating conditions
    • G09G2320/02—Improving the quality of display appearance
    • G09G2320/0233—Improving the luminance or brightness uniformity across the screen
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2320/00—Control of display operating conditions
    • G09G2320/02—Improving the quality of display appearance
    • G09G2320/029—Improving the quality of display appearance by monitoring one or more pixels in the display panel, e.g. by monitoring a fixed reference pixel
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2320/00—Control of display operating conditions
    • G09G2320/08—Arrangements within a display terminal for setting, manually or automatically, display parameters of the display terminal
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K59/00—Integrated devices, or assemblies of multiple devices, comprising at least one organic light-emitting element covered by group H10K50/00
    • H10K59/10—OLED displays
    • H10K59/18—Tiled displays
    • 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
    • Y02B20/30—Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED]

Definitions

  • This invention relates to organic light emitting diodes, in particular to
  • OLED lighting sources constructed from multiple OLED tiles.
  • OLED devices are comprised of two electrodes and an organic light emitting layer.
  • the organic layer is disposed between the two electrodes.
  • One electrode is the anode and the other electrode is the cathode.
  • the organic layer is structured such that when the anode has a voltage bias that is sufficiently positive relative to the cathode, holes are injected from the anode and electrons are injected from the cathode.
  • the necessary voltage bias depends upon the materials used for the organic layers.
  • the holes and electrons recombine within the organic layer to induce an exited state in a molecule comprising the organic layer. Light is emitted during the process of excited molecules relaxing to their ground state.
  • the anode is typically manufactured from a high work function material such as a Transparent Conducting Oxide (TCO), and the cathode is typically manufactured from a highly reflecting material such as aluminum or silver.
  • TCO Transparent Conducting Oxide
  • the organic layer can be comprised of a single organic film, or it can be comprised of a stack of multiple organic films. OLED devices are useful as indicators and displays can be constructed from patterned arrays of OLED devices.
  • OLED lighting sources for general illumination can be constructed from a plurality of smaller OLED tiles.
  • the OLED tiles can be arranged in matrix form. This is known as OLED tiling and may have several advantages over a single monolithic large area OLED lighting source such as: the production yield is increased significantly, the power loss can be reduced by series connection, the fault tolerance of the lighting device is increased, and the geometric appearance of the tiled OLED lamp can be easily customized because OLED tiles which are shaped, such as: strips, square of different aspects ratios and etc., can be used.
  • the invention provides for a method, an electronic device, a tiled OLED lighting source, and an OLED kit. Embodiments of the invention are given in the dependent claims.
  • Embodiments of the invention address the aforementioned problems by using the driver electronics for the OLED lighting source to adjust the electrical power to every single OLED tile of the arrangement so the variation of at least one optical property of the OLED lighting source is minimized.
  • Optical properties of OLED tiles are defined herein as photometric, radiometric, or spectral properties of the light emitted from an OLED tile. As the power supplied to an OLED tile varies, the optical property will change.
  • An OLED tile is defined herein as an OLED device which is placed in a pattern with other OLED devices.
  • the terms OLED device and OLED tile can be used interchangeably.
  • photometric quantities are luminous energy, luminous flux, luminous intensity, luminance, illuminance, luminous emittance, and luminous efficacy.
  • Photometric quantities account for the varying sensitivity of the human eye to different wavelengths of visible light. Minimizing the variance of one or more photometric quantities is advantageous, because the light sources will be perceived as having a uniform brightness.
  • radiometric properties are radiant energy, radiant flux, radiant intensity, radiance, irradiance, radiant exitance, radiant emittance, radiosity, spectral radiance, and spectral irradiance. Making the radiometric properties more uniform is useful when the amount of energy from a lighting source needs to be uniform such as a light source for photolithography.
  • the spectral properties of the light emitted from OLED tiles can be measured with a spectrometer.
  • OLED tiles can be constructed where the color of the light emitted changes as the applied current or voltage changes. It is also possible to construct multiple layered OLED tiles, where each layer of the OLED tile produces light with different spectral emissions. By controlling the electrical power to the different layers, the color of the OLED tile can be controlled. It is understood that the OLED tiles described herein can also refer to OLED tiles with multiple layers.
  • Electro-Optical properties are defined herein as the relationship between the electrical power applied to an OLED tile and the resulting optical property. Electro- Optical properties are typically expressed in terms of an optical property as a function of the applied voltage and/or current. An example would be the luminous emittance as a function of the applied current. Electro-Optical properties are intrinsic properties of each OLED tile, and they vary from tile to tile even within the same manufacturing batch. The control electronics of embodiments of the invention compensate for inter tile variations of the electro -optical properties to increase the uniformity of the resulting optical properties.
  • the amplitude of the voltage or the current applied to an OLED tile can be controlled. This affects the amount of light produced and in some cases the spectral content (color) of the light.
  • the OLED tiles can also be switched on and off repeatedly at a rate higher than the persistence of vision. This changes the perception of the brightness of the tile. Either or both of these techniques can be used to adjust the optical properties of the OLED tiles. Using both has the advantage that more than one quantity can be controlled. An example would be the independent control of the luminance and the color of the OLED tile.
  • each of the individual layers can have its current or voltage amplitude or voltage controlled in addition to each layer being switched on and off at an independent rate and/or an independent duty cycle. For this case, there is more than one solution for a desired luminance and color.
  • a primary aspect of the invention is an automated procedure that determines
  • This procedure can be replicated for other or multiple optical properties of the OLED tiles.
  • Embodiments of the invention provide for a method for improving the uniformity of at least one optical property of a tiled OLED lighting source.
  • Tiled OLED lighting sources comprise at least two OLED tiles.
  • the method comprises several steps.
  • electrical power is applied to the OLED tiles with a power providing means, the power providing means comprises a control means that is adapted for controlling electrical power to each of the OLED tiles.
  • Controlling the electrical power to each of the OLED tiles is defined herein as meaning controlling the voltage, the current, or the current and the voltage to each of the OLED tiles. It is also understood that controlling the electrical power to each of the OLED can also be pulsing the electrical power to the OLEDs at a specific frequency and duty cycle.
  • controlling the electrical power is understood to be controlling the power to each layer.
  • at least one optical property of each OLED tile is measured as a function of electrical power applied to the OLED tile. This is done to determine at least one electro -optical property of each OLED tile.
  • the control means are modified using the electric optical properties for compensating the variation of the electric optical properties on the uniformity of the electrical properties of the OLED tiles. This method has the advantage of being able to make one or more optical properties of OLED lighting source more uniform. Even within a single manufacturing run there can be variations in the electro -optical properties. When OLED tiles are in close proximity, it is very easy for the human eye to detect differences in such properties as the brightness or the color.
  • the differences within the electro -optical properties of the individual OLED tiles can be compensated for.
  • the method of compensating depends upon the optical property or optical properties that are being measured. If the luminance or brightness is being measured, very typically the luminance is proportional to the applied current. In this case only one pair of optical and electrical measurements is needed. However, if different types of OLED devices are being used, for instance one where the color depends upon the current and the brightness also depends upon the current, then a more complicated function of the optical property depending on the electrical power may need to be measured. The measurements needed to compensate for multi layered OLED devices can also be very complicated.
  • the control means can be implemented in a variety of ways. It can be a simple analogue circuit, or it could be a more complicated computer or microprocessor controlled system.
  • one of the optical properties that is measured is the luminance.
  • the luminance is the brightness that is perceived.
  • the human eye is very sensitive to changes of brightness particularly when you have large tiles adjacent to each other. It is very easy for the human eye to detect differences in the luminance.
  • the advantage is that if one of the optical properties is the luminance, then the method can compensate for differences in the luminance between the different OLED tiles and the lamp will have a much more uniform appearance to the human eye.
  • one of the optical properties is the color. It is an advantage to compensate for the color, because for lamps one of the features that the human eye notices is also the color. If two OLED tiles are adjacent to each other and they have different spectral or color properties this would be very easy to notice. Compensating for variations in color gives a tiled OLED lighting source a much more uniform and pleasing appearance.
  • the electrical power to each of the OLED tiles is controlled by adjusting either the current or the voltage applied to each of the OLED tiles.
  • Diodes have a current-voltage characteristic. It is customary to talk about using the current to control a diode or an OLED type device, but an equivalent way is also to control the voltage.
  • An advantage of controlling the current or the voltage applied to each of the OLED tiles is that this can be compared to measured optical properties and a functional relationship between the optical property or properties can be constructed. This allows the compensation for the variation of the optical properties.
  • the electrical power to each of the OLED tiles is controlled by repeatedly switching on and off the OLED tiles.
  • the switching of the OLED tiles is performed faster than the persistence of vision. This is an advantage, because when they are switched faster than the persistence of vision, then this can be used to reduce the perceived brightness of the OLED tile. It would be possible to adjust the brightness by just adjusting the current, but some OLED tiles have a variation in color depending upon the current also. By adjusting the duty cycle of the power applied to the OLED tile this allows the brightness and then the color could possibly be controlled by controlling the current.
  • This scheme is also advantageous, because only a single, constant current source is needed. This is more cost effective than having multiple current or voltage sources which are adjustable.
  • the invention provides for an electronic device which is used for powering a tiled OLED lighting device.
  • the OLED lighting device comprises at least two OLED tiles.
  • the electronic device comprises a power providing means adapted for providing electrical power to each of the OLED tiles and a power providing means comprising a control means for adjusting the electrical power. This is used for compensating the effect of the variation of at least one electro -optical property of the OLED tiles. This is useful for improving the uniformity of at least one optical property of the OLED lighting device.
  • This electronic device has the advantage that it has a means for compensating for the variation of the electrical optical properties of the OLED tiles. This is advantageous, because compensating for the electro -optical properties of the OLED device allows for the measured or perceived optical property of the OLED lighting device to be made more uniform.
  • the optical properties compensated for by the electronic device compensates are the luminance and/or the color.
  • Compensating for the luminance is an advantage, because this is equivalent to what we perceive as brightness. When lamps are adjacent to each other differences in brightness can be very disturbing or easily noticed by people. Compensating for this makes the lamp more aesthetically pleasing. It is also the same for the color or the spectral composition of a light coming from the lamp. The human eye will very easily notice small variations in the color of the individual OLED tiles which make up the OLED lighting device.
  • the power providing means comprises a switching means adapted for switching the OLED tile on and off repeatedly at a frequency faster than the persistence of vision. The advantage of switching the OLED tiles on and off faster than the persistence of vision has already been discussed.
  • the power providing means is adapted for switching the power to each OLED tile at an independent frequency and/or independent duty cycle.
  • the advantage to this is that the perceived brightness is able to be changed. When the duty cycle is altered, the fraction of the time that the OLED tile is lit changes.
  • the electronic device has a power providing means which comprises a set of power converters adapted for powering the OLED tiles.
  • a power converter for each of the OLED tiles and the power converters are adapted for either adjusting the current or the voltage applied to each OLED tile. This is advantageous, because this allows compensating for the electro-optical properties of the OLED tiles. The advantage of this has been mentioned previously.
  • the electronic devices control means is an analogue electronic circuit.
  • the optical property electro control is the brightness or the luminance.
  • the luminance is simply proportional to the current. This means that the method of compensating for the variation of this electro -optical property is relatively simple. This could be accomplished by an operator adjusting something as simple as a trimpot on the power supply.
  • Analogue circuits can also be used for compensating for more complicated OLED devices such as devices that also have a control for the color.
  • the electronic device has a control means which comprises a logic circuit.
  • the electronic devices further comprises a lookup table.
  • the lookup table is adapted for providing values usable by the control means for compensating for the variation of the electro -optical properties of the OLED tiles.
  • This can be implemented with a microcontroller or it can also be implemented with a computer.
  • Using a lookup table is very advantageous, because the electro -optical properties of the individual OLED tiles can be measured in advance, and then can be used to construct a lookup table which is used to compensate for variations of these electro -optical properties. When the lamp is then operated, the optical properties of interest can be made uniform. Using a lookup table allows for very complicated compensation schemes.
  • the lookup table can contain information about the necessary current, the necessary duty cycle of the power applied to the OLED tile, or both.
  • the control means is a logic circuit and the electronic device further comprises a trained software module.
  • the trained software module provides values usable by the control mean to compensate for the variation of the electro -optical properties of the OLED tiles.
  • the trained software module can be implemented with a neural network.
  • Other possible examples of trainable software modules are modules constructed using one of the following techniques: fuzzy logic, Bayesian analysis, principal component analysis, perception learning algorithm, Linear discriminant analysis, regression analysis, ANOVA, factor analysis, and associative memory regression analysis. The relationship between the current and the color or other optical properties of interest can be quite complicated.
  • a trainable software module would allow for these complicated relationships to be controlled in an efficient manner. This is also an advantage, because the manufacturer can measure the electro -optical properties of the OLED tiles and use this to train the software module and simply install the software module in the logic circuit.
  • the trainable software module can be connected with a control system that is operable for adjusting the electrical power to the OLED tiles. This can be used for training the software module and it could also be used in conjunction with the control system to adjust the optical properties when the OLED lighting system is in operation.
  • the electronic device is further comprised of a selection means for selecting at least one desired optical value for the optical properties of OLED lighting source.
  • the control means is adapted for minimizing the variation of the OLED tiles from the desired optical values. This is an advantage because this allows the lighting source to be dimmed, brightened, or to have a change in the color of the lights. In general, adding a selection means allows the adjustment of the optical properties of the light.
  • the invention provides for a tiled OLED lighting source comprising two or more OLED tiles and the electronic device that was previously described when the two or more OLED tiles are connected to the power providing means.
  • This arrangement is advantageous, because this is essentially an OLED lamp, comprised of OLED tiles and electronics which are able to compensate for the variations of the electro -optical properties of the individual OLED tiles.
  • the invention provides for an OLED lighting kit comprising two or more OLED tiles and the electronic device that was previously described.
  • OLED lighting source as described previously may not be constructed when it is delivered to the customer.
  • very large OLED tiles could be used to replace ceiling tiles in a room and then the ceiling tiles could be used for lighting.
  • the OLED tiles would be installed in the ceiling first, and then they would be connected to the electronics.
  • Fig. 2 Diagram showing an embodiment of a tiled OLED lighting device
  • Fig. 3 Flow diagram for an embodiment of a method improving the uniformity the luminous intensity by, modulating the current to the OLED tiles,
  • Fig. 4 schematic diagram of an embodiment of a tiled OLED lighting source which modulates the current to each OLED tile
  • Fig. 5 schematic diagram of an embodiment of a tiled OLED lighting source which controls the amplitude of the electrical power to each OLED tile
  • Fig. 6 idealized schematic diagram of an embodiment of a tiled
  • OLED lighting source which modulates the current to each OLED tile.
  • Figure 1 shows an embodiment of a method for improving uniformity of at least one optical property of a tiled OLED lighting source.
  • the method consists of applying electrical power to OLED tiles 100, measuring at least one optical property of each OLED tile 102 and then finally modifying the control means 104.
  • the optical properties of the OLED tiles are measured as a function of voltage and/or current applied to the OLED tiles. This is used to determine the electro -optical properties of each of the OLED tiles.
  • the electro -optical properties of the OLED tiles Once the electro -optical properties of the OLED tiles have been determined, they can be used to modify the control means.
  • the electro -optical properties of the OLED tiles are intrinsic properties of the tiles, whereas the optical properties of the tiles change as the current or voltage through a particular tile changes. For example, the brightness typically increases as the current is increased through an OLED tile. Modifying the control means based on the measured electro -optical properties enables the optical property of the lighting source to become more uniform.
  • FIG. 2 shows an embodiment of an exemplary tiled OLED lighting device 200.
  • the OLED lighting device comprises a frame 202 and OLED tiles 1.1, 1.2, 1.3, 1.4, 2.1, 2.2, 2.3, 2.4, 3.1, 3.2, 3.3, 3.4 which are arranged in a rectangular pattern.
  • a tiled OLED lighting source comprises a tiled OLED lighting device 200 and driving electronics adapted powering the OLED tiles 1.1, 1.2, 1.3, 1.4, 2.1, 2.2, 2.3, 2.4, 3.1, 3.2, 3.3, 3.4.
  • the OLED tiles are labeled 1.1, 1.2, 1.3, 1.4, 2.1, 2.2, 2.3, 2.4, 3.1, 3.2, 3.3, and 3.4.
  • the tiled OLED lighting device 200 also shows electrical connections 204.
  • Arranging the measured optical properties in a matrix enables the calculation of factors for correcting for variations in the electro -optical properties.
  • the technical realization requires the measurement of the OLED tile 1.1, 1.2, 1.3, 1.4, 2.1, 2.2, 2.3, 2.4, 3.1, 3.2, 3.3, 3.4 efficacy and the control of the average OLED tile 1.1, 1.2, 1.3, 1.4, 2.1, 2.2, 2.3, 2.4, 3.1, 3.2, 3.3, 3.4 current.
  • the tile efficacy can be measured repeatedly during operation of the lighting device e.g. via photo (flux) sensor or alternatively during assembly of the lighting device at the manufacturers site.
  • the measured tile efficacy is stored in a Look Up Table (LUT) if it is measured once or continuously monitored so that it can be used to modify the average driving current.
  • LUT Look Up Table
  • Figure 3 shows a method for modulating the current to OLED tiles for improving the uniformity of at least one optical property.
  • the method consists of using stored or measured current efficiency measurements 300 for each tile. Using a reference value 302 for the desired luminous intensity these two values are then used to calculate 304 a reference value for driving the current.
  • the reference values for driving the current are then stored 306 and the values for the driving current Irf n 308 are placed into memory. To operate the lamps an initial value for Irf n 316 is used.
  • FIG 4 shows an embodiment of a tiled OLED lighting source with an arbitrary number of OLED tiles 408, 410, 412.
  • the OLED lighting source consists of a power source 400 which is used to power a power converter 402.
  • the power converter 402 then delivers power to both the tiled OLED device 406 and the controller 404.
  • the tiled OLED device consists of N different OLED tiles 408, 410, 412.
  • OLED tile 1 408 is shown
  • OLED tile 2 410 is shown and the last OLED tile number N 412 is shown.
  • This diagram represents a circuit for an arbitrary number of OLED tiles 408, 410, 412.
  • the OLED tiles 408, 410, 412 are connected in series with lines for connecting to Field Effect Transistor (FET) 426, 428, 430 switches.
  • FET Field Effect Transistor
  • the controller 404 comprises a reference value 414 and a lookup table (LUT) 416 that are connected to the modulator control 418.
  • the modulator control is connected to the power converter 402.
  • the reference value 414 is a value which is given to the modulator control 418 that is used to set desired optical properties of the tiled OLED device 406.
  • the LUT 416 contains values that are used by the modulator control 418 for the purpose of properly controlling the power delivered to each OLED tile 408,410, 412.
  • the modulator control 418 is connected to JV different switch control units 420, 422, 424.
  • the switch control units 420, 422, 424 are used to control FETs 426, 428, 430.
  • switch control unit 420, 422, 424 and a FET 426, 428, 430 corresponding to each OLED tile 408,410, 412.
  • the FET 426, 428, 430 is connected in parallel with its OLED tile 408,410, 412.
  • FET 1 426 is connected in parallel with OLED tile 1 408.
  • FET 2 428 is connected in parallel with OLED tile 410 and so on.
  • the last FET N 430 is connected in parallel with OLED tile number N 412.
  • Each of the FET 426, 428, 430 and OLED tile 408,410, 412 pairs are connected to each other in series. When one of the FETs is activated, the current flows through the FET 426, 428, 430 and not through the OLED tile 408,410, 412.
  • the FETs 426, 428, 430 can be used to switch the OLED tiles 408,410, 412 on and off.
  • the modulator control is able to control the apparent brightness by switching the OLED tiles 408,410, 412 rapidly on and off.
  • the circuit and control arrangement described in this embodiment has the advantage that a single current source is used and then the switches are simply used to modulate whether the OLED tile 408,410, 412 is on or off at a certain time.
  • the brightness is controlled by modulating the duty cycle of OLED tile 408,410, 412 at a rate faster than the persistence of vision.
  • the system consists of a power source 400 delivering a constant average current to a tiled OLED device 406 where all tiles are connected in series.
  • bypass elements (FET switches) 426, 428, 430 are arranged so that by closing the bypass element 426, 428, 430 the average current of the respecting tile can be changed.
  • the average current flowing through each OLED tile 408,410, 412 can be changed.
  • the driving current itself is determined by a reference value 414 which is either built in by design or adjustable e.g. via a control or lighting network interface.
  • FIG. 5 shows a different embodiment of the invention.
  • the OLED tiles 510, 512, 514 are controlled by independent power converters 502, 504, 506.
  • a power converter 502, 504, 506 is defined herein as a controller adapted for regulating the current or voltage applied to an OLED tile 510, 512, 514, cyclically switching the electrical power applied to the OLED tile 510, 512, 514 on and off, or both.
  • There is a main power source 500 which supplies power converters 502, 504, 506 to an arbitrary number of JV different power converters 502, 504 and 506. Only power converter 1 502, power converter 2 504 and the last power converter number N 506 are shown in this diagram.
  • tiled OLED device 508 which comprises an arbitrary number of JV different OLED tiles 510, 512, 514.
  • Power converter 1 502 is connected to OLED tile 1 510
  • power converter 2 504 is connected to OLED tile 2 512 and the last power converter
  • power converter N 506 is connected to OLED tile number N 514.
  • master controller 516 which is used for controlling each of the power converters 502, 504, 506.
  • the master controller 516 uses a reference value 518 with a lookup table 520 to calculate the proper power that should be delivered to each OLED tile 510, 512, 514.
  • the master controller 516 is connected to each of the power converters 502, 504, 506 by a communication line 522.
  • the communication line 522 allows the master controller 516 to control the electrical power applied to each OLED tile 510, 512, 514.
  • the communication line 522 can be either analogue or digital.
  • Figure 6 shows an embodiment of a generalization of the OLED lighting source architecture which modulates the current to control the brightness of OLED tiles 610, 612, 614.
  • This embodiment consists of a power source 600 which provides a constant current.
  • This is connected to a power bus 602.
  • the power bus 602 is connected to TV different current modulators 604, 606, 608, current modulator 1 604, current modulator 2 606 and current modulator N 608.
  • the power bus 602 is connected such that each current modulator 604, 606, 608 receives the same current.
  • Current modulator 1 604 is connected to OLED tile 1 610
  • current modulator 2 606 is connected to OLED tile 2 612
  • current modulator 608 is connected to OLED tile N 614.
  • N different reference values 616 are communicated with each of the current modulator over N different communication lines 618.
  • these communication lines 618 can be implemented as either analogue lines or as digital signals. For a digital signal the communication can be over N different communication lines 618 or it can be multiplexed on one or more communication lines 618.
  • FIG. 5 A power supply architecture which allows controlling the tile currents individually is shown in figure 5.
  • a master slave concept is applied, where the slave power converters 502, 504, 506 generate the individual tile currents while the master controller 516 calculates and communicates the reference values 518 to the slave power converters 502, 504, 506.
  • the power supply architectures of figures 4 and 5 can be generalized as shown in figure 6 comprising:
  • a set of current reference values 414, 518, 616 The current modulators 426, 428, 430, 502, 504, 506, 604, 606, 608 adjust the current delivered to the individual OLED tiles 408, 410, 412, 510, 512, 514, 610, 612, 614 according to a set of reference values 302, 414, 518, 616 which are calculated according to the method of figure 3.
  • the reference values 302, 414, 518, 616 can be either stored in memory 308, stored as a LUT 416, 520, implemented in hardware, and/or calculated continuously.
  • the reference values can be implemented in hardware by using a trimmable resistance. LIST OF REFERENCE NUMERALS:

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Computer Hardware Design (AREA)
  • General Physics & Mathematics (AREA)
  • Theoretical Computer Science (AREA)
  • Electroluminescent Light Sources (AREA)

Abstract

L’invention porte sur un procédé pour améliorer l’uniformité d’au moins une propriété optique d’une source d’éclairage à dalles OLED comprenant au moins deux dalles OLED, le procédé comprenant : l’application d’une énergie électrique aux dalles OLED à l’aide d’un moyen de fourniture d’énergie, le moyen de fourniture d’énergie comprenant un moyen de commande conçu pour commander l’énergie électrique fournie à chacune des dalles OLED, la mesure d’au moins une propriété optique de chacune des dalles OLED en fonction de leur énergie électrique respective pour déterminer au moins une propriété électro-optique de chaque dalle OLED, la modification du moyen de commande à l’aide des propriétés électro-optiques pour compenser l’effet de la variation des propriétés électro-optiques sur l’uniformité des propriétés optiques des dalles OLED.
PCT/IB2009/054529 2008-10-20 2009-10-15 Procédé et dispositif électronique pour améliorer l’uniformité optique de sources d’éclairage à dalles oled WO2010046811A1 (fr)

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JP2013115001A (ja) * 2011-11-30 2013-06-10 Panasonic Corp 有機ｅｌ素子点灯装置およびこれを用いた照明器具
WO2014067830A1 (fr) * 2012-10-31 2014-05-08 Tridonic Jennersdorf Gmbh Procédé et dispositif pour commander des del, avec une correction de température, au moyen de tables de consultation
US9883565B2 (en) 2014-08-26 2018-01-30 Osram Oled Gmbh Method for operating an optoelectronic assembly and optoelectronic assembly
US10231311B2 (en) 2014-08-26 2019-03-12 Osram Oled Gmbh Method for operating an optoelectronic assembly and optoelectronic assembly

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TWI695366B (zh) * 2019-03-29 2020-06-01 大陸商北京集創北方科技股份有限公司 具有類神經網路計算功能的自發光元件顯示面板模組、驅動晶片及電子裝置

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