EP1697920B1 - Device for displaying images on an oled active matrix - Google Patents

Device for displaying images on an oled active matrix Download PDF

Info

Publication number
EP1697920B1
EP1697920B1 EP04816458A EP04816458A EP1697920B1 EP 1697920 B1 EP1697920 B1 EP 1697920B1 EP 04816458 A EP04816458 A EP 04816458A EP 04816458 A EP04816458 A EP 04816458A EP 1697920 B1 EP1697920 B1 EP 1697920B1
Authority
EP
European Patent Office
Prior art keywords
emitters
data
modulator
voltage
display device
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.)
Not-in-force
Application number
EP04816458A
Other languages
German (de)
French (fr)
Other versions
EP1697920A1 (en
Inventor
Philippe Le Roy
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.)
THOMSON LICENSING
Original Assignee
Thomson Licensing SAS
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 Thomson Licensing SAS filed Critical Thomson Licensing SAS
Publication of EP1697920A1 publication Critical patent/EP1697920A1/en
Application granted granted Critical
Publication of EP1697920B1 publication Critical patent/EP1697920B1/en
Not-in-force legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

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
    • 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]
    • G09G3/3225—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] using an active matrix
    • G09G3/3233—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] using an active matrix with pixel circuitry controlling the current through the light-emitting element
    • 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
    • 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]
    • G09G3/3275—Details of drivers for data electrodes
    • G09G3/3283—Details of drivers for data electrodes in which the data driver supplies a variable data current for setting the current through, or the voltage across, the light-emitting elements
    • 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]
    • G09G3/3275—Details of drivers for data electrodes
    • G09G3/3291—Details of drivers for data electrodes in which the data driver supplies a variable data voltage for setting the current through, or the voltage across, the light-emitting elements
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2300/00—Aspects of the constitution of display devices
    • G09G2300/04—Structural and physical details of display devices
    • G09G2300/0404—Matrix technologies
    • G09G2300/0417—Special arrangements specific to the use of low carrier mobility technology
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2300/00—Aspects of the constitution of display devices
    • G09G2300/08—Active matrix structure, i.e. with use of active elements, inclusive of non-linear two terminal elements, in the pixels together with light emitting or modulating elements
    • G09G2300/0809—Several active elements per pixel in active matrix panels
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2300/00—Aspects of the constitution of display devices
    • G09G2300/08—Active matrix structure, i.e. with use of active elements, inclusive of non-linear two terminal elements, in the pixels together with light emitting or modulating elements
    • G09G2300/088—Active matrix structure, i.e. with use of active elements, inclusive of non-linear two terminal elements, in the pixels together with light emitting or modulating elements using a non-linear two-terminal element
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2310/00—Command of the display device
    • G09G2310/02—Addressing, scanning or driving the display screen or processing steps related thereto
    • G09G2310/0243—Details of the generation of driving signals
    • G09G2310/0248—Precharge or discharge of column electrodes before or after applying exact column voltages
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2310/00—Command of the display device
    • G09G2310/02—Addressing, scanning or driving the display screen or processing steps related thereto
    • G09G2310/0243—Details of the generation of driving signals
    • G09G2310/0251—Precharge or discharge of pixel before applying new pixel voltage
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2310/00—Command of the display device
    • G09G2310/06—Details of flat display driving waveforms
    • 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
    • G09G2320/04—Maintaining the quality of display appearance
    • G09G2320/043—Preventing or counteracting the effects of ageing

Definitions

  • the present invention relates to an active matrix image display device.
  • passive matrix OLED displays are already widely marketed. However, they consume a lot of electrical energy and have a reduced life.
  • Active Matrix OLED displays have built-in electronics, and have many benefits such as reduced power consumption, high resolution, compatibility with video rates, and longer life than passive matrix OLED displays.
  • the display devices comprise a display panel formed in particular by a network of light emitters.
  • Each light emitter is linked to a pixel or a subpixel of an image to be displayed and is addressed by an array of column electrodes and line electrodes via an addressing circuit.
  • the addressing circuits include current modulators capable of driving the current flowing through the emitters and therefore the luminance of each sub-pixel of the display panel.
  • these modulators are thin-film transistors, called Thin Film Transistor (TFT) transistors, made of crystalline poly-silicon using low-temperature polycrystalline silicon (LTPS) technology.
  • TFT Thin Film Transistor
  • LTPS low-temperature polycrystalline silicon
  • this technique introduces local spatial variations in the threshold threshold voltage of thin-film transistors. These variations are due to the fact that the seams and grain size of the poly-silicon are not sufficiently controllable during the crystallization phase of amorphous silicon in polycrystalline silicon.
  • the TFT transistors comprising the same display panel have different trigger threshold voltages.
  • TFT transistors fed by the same supply voltage and controlled by identical data voltages or currents generate currents of different intensity.
  • an emitter generally emits a light intensity directly proportional to the current flowing through it
  • the heterogeneity of the trigger thresholds of the crystalline poly-silicon transistors causes non-uniformity of brightness of a screen formed by a matrix of such transistors. This results in differences in luminance levels and obvious visual discomfort for the user.
  • a control circuit of a transmitter comprising a comparison unit adapted to compare the drain current I d flowing through the modulator to a reference current during a programming step of the control circuit.
  • this circuit requires the implementation of a switching unit by transmitter to switch the power source of the transmitter between the programming step and a transmitter transmission end stage.
  • This switching unit comprises two thin film transistors and an inverting amplifier. This circuit is difficult to manufacture and not very economical.
  • He is known in particular by the document EP 1 381 019 active matrix display devices comprising OLED transmitters, transmitter power supply means, modulators and means for compensation of the tripping threshold voltages of the modulators.
  • the compensation means comprise means for comparing the drain current passing through a selected transmitter to a display setpoint.
  • the transmitters are not powered by the same power supply means both during the programming phases and the successive transmission phases for the display of the images, which requires a specific electrode array for each power mode.
  • He is known in particular by the document JP-2002/278513 a display device comprising OLED transmitters, transmitter power supply means, modulators and voltage compensation means, tripping threshold of modulators.
  • the emitters are fed by the same power supply means during the programming phases and the successive transmission phases for the display of the images, but the compensation of the threshold voltages is carried out during a phase of calibration prior to displaying the images.
  • the compensation means comprise means for measuring the drain current passing through a selected transmitter and means for comparing this drain current to a calibration setpoint of this emitter. These compensation means therefore do not make it possible to compensate for variations in triggering threshold voltages that would appear during the display phase of the images.
  • active matrix display devices comprising OLED transmitters, modulators and means for compensating tripping threshold voltages of the modulators.
  • the compensation means comprise means for measuring the drain current passing through a selected transmitter and means for comparing this drain current with a display setpoint.
  • the means for measuring the drain current are specific to each emitter of a column.
  • they comprise a resistor, two electrodes and two switches for each emitter of a column. This architecture is therefore complex and expensive.
  • An object of the present invention is the implementation of a control circuit less complex and therefore less expensive.
  • the figure 1 represents an active matrix display device according to the invention.
  • Such a device comprises a plurality of light emitters 2 forming a network of rows and columns, power supply means V dd of the emitters 2 and transmitter transmission control means 3.
  • V dd power supply means
  • transmitter transmission control means 3 transmitter transmission control means
  • the emitters 2 of the display panel are organic electroluminescent diodes. They include an anode and a cathode. They are each associated with a pixel when the panel is monochrome or a sub pixel when the display panel is full color. They emit a luminous intensity directly proportional to the current passing through them.
  • the power supply means V dd of the transmitters 2 comprise a DC voltage generator per column of transmitters 2. This generator V dd feeds a line 4, to which is connected all the emitters 2 of this column.
  • the control means 3 of the display device comprise an addressing circuit 6 for each transmitter, an array of selection electrodes 8 of line and column addressing and compensation means 12 of the tripping threshold modulators.
  • An addressing circuit 6 is connected to each transmitter 2 of the display panel.
  • the addressing circuit represented on the figure 1 is a classic structure circuit. In this type of circuit, the anode of the emitter forms the interface with the active matrix and the cathode of the emitter is connected to a ground electrode or a negative voltage.
  • the addressing circuit 6 comprises a current modulator 14, a switch 16 and a storage capacitor 18.
  • the current modulator 14 is a transistor based on a technology using polycrystalline silicon (Poly-Si) or amorphous silicon (a-Si) deposited in thin layers on a glass substrate.
  • Such components comprise three electrodes: a drain electrode and a source electrode between which the modulated current flows, and a gate electrode to which a data driving current I data is applied.
  • the thin film transistors are of type n or p.
  • the modulator 14 shown on the figure 1 is of type p. Its source is connected directly to the supply electrode V dd and its drain is connected directly to the anode of the emitter 2 so that in operation the modulated electric current flows between the source and the drain.
  • the modulator 14 is of type n, the drain is connected to the supply electrode V dd and the modulated electric current then flows between the drain and the source.
  • the power supply generator V dd is directly connected to all the modulators 14 for controlling the emitters of a column, so that it is always able to power a transmitter 2 selected and addressed whatever the step of process of transmitting an image frame.
  • the corresponding transmitter is powered by the single generator V dd .
  • the switch 16 is also a technology-based transistor using polycrystalline silicon (Poly-Si) or amorphous silicon (a-Si) deposited in thin layers.
  • One of its electrodes (drain or source) is connected to the addressing electrode 10 and the other electrode (drain or source) is connected to the gate of the modulator 14. Its gate is connected to the electrode 8 of line selection.
  • the storage capacitor 18 is disposed between the gate and the source of the modulator 14 to maintain the brightness of the transmitter 2 during an image frame duration. This capacitance is adapted to substantially maintain the constant voltage on the gate of the modulator 14 during a time interval corresponding to the frame duration.
  • the array of selection electrodes 8 and addressing 10 makes it possible to select and address a specific transmitter among all the transmitters of the display panel.
  • Each selection electrode 8 is connected to the gate of the switches 16 of a line and is able to transmit a selection voltage V select to all the emitters 2 of this line.
  • the selection voltage V select is a logical data selection of the transmitters.
  • Each addressing electrode 10 is connected to the source or the drain of the switches 16 of a column and is able to address a data driving current I data to the gate of the modulator 14 of the set of addressing circuits 6 of this column according to a data set U c .
  • the intensity of current flowing in the emitter is proportional to the amplitude of the current I data which is applied to the electrode 10.
  • the selection and addressing electrodes 10 are each controlled by a corresponding control driver 20, 22 for applying V select selection voltages and U c data instructions to the transmitters.
  • a corresponding control driver 20, 22 for applying V select selection voltages and U c data instructions to the transmitters.
  • the compensation means 12 of the triggering thresholds are able to compensate for the triggering threshold volt V.sub.th of all the modulators 14 addressed by the addressing electrode 10 of this column.
  • This controller comprises a measurement unit 26, a comparison unit 28, a control generator 30, a switch 32, a control unit 34 and initialization means 36 of the addressing circuits 6 of this column.
  • the measurement unit 26 is connected to the power supply electrode 4 of all the emitters of a column.
  • the measurement unit 26 is able to measure a value representative of the drain current I d of a modulator 14 selected by the selection electrode 8 and the gate of which a driving current I data is applied.
  • the role of the unit 26 is to extract from the sum of the currents measured in the line 4, only the current of the modulator 14 being programmed.
  • An exemplary embodiment of the measurement unit 26 will be described below in connection with the figure 2 .
  • the comparison unit 28 comprises two input terminals adapted to receive the data set U c addressed by the control driver 22 and a value representative of the drain current I d measured by the measurement unit 26.
  • the data set U c is a data voltage.
  • the comparison unit 28 is adapted to compare the amplitude of the voltage representative of the drain current I d and the amplitude of the data voltage U c during a so-called programming step C of the addressing circuit 6.
  • the comparison unit 28 comprises an output terminal capable of transmitting a warning signal S when the amplitude of the voltage representative of the intensity of the drain current I d and the amplitude of the data voltage.
  • U c are linked by a predetermined coefficient k of proportionality.
  • the warning signal S is a logic signal sent to the control unit 34.
  • the data setpoint is a digital datum or a data intensity.
  • the control generator 30 is a DC generator capable of supplying a control current I data which is a function of the data setpoint Uc applied to this generator. It is connected in series with the addressing electrode 10. It is able to receive the data voltage U c addressed by the column control driver 22 and to generate a control current I data whose amplitude is modulated in depending on the amplitude of the data voltage U c .
  • the switch 32 is connected in series at the output of the control generator 30. It is able to switch between a closed position in which the control current I data supplies the addressing electrode of all the control circuits. addressing 6 of the column and an open position in which the addressing circuits 6 are not addressed.
  • the control unit 34 is connected to the driver 22, to the output of the comparison module 28 and to the switch 32 to receive the data voltage U c and the warning signal S and to control the switching of the switch 32.
  • the control unit 34 is able to control the closing of the switch 32 on receipt of the data voltage U c and the opening thereof on receipt of the warning signal S.
  • the duration of the driving current I data generated is modulated depending on the threshold voltage V th unique to each modulator 14 as will be explained hereinafter.
  • the initialization means 36 of the addressing circuits 6 are connected in parallel to the generator 30 so that the image of a frame is not influenced by the image of the previous frame. They are able to emit a square voltage to discharge the storage capacity 18 and a parasitic capacitance induced by the display panel. They comprise a DC voltage generator 38 and a switch 40. The switch 40 is connected to the control unit 34. The control unit 34 is connected to the driver 20 to control the closing of the switch 40 on receipt of the selection voltage V select .
  • the addressing circuit 6 comprises a shunt switch of the storage capacity 18.
  • the figure 2 represents an embodiment of a unit 26 for measuring a value representative of the drain current I d flowing through the modulator 14 of the control circuit to which programming step begins.
  • Such a measurement unit 26 is connected to the supply line 4 of the emitters 2 of a column. It comprises a block 41 for determining the drain current I d , a low-pass filter 42, a differential block 43 and an amplifier 44.
  • the determination block 41 comprises a resistor 45, for example from 1 to 10 kilos Ohms, connected in series with the supply line 4 of the transmitters and a precision operational amplifier 46 whose terminals are connected to the supply line 4 on either side of the resistor 45.
  • the output of the amplifier 46 is connected on the one hand to the low-pass filter 42 , itself connected to a negative terminal of an amplifier 47 of the differential block 43 and secondly to a positive terminal of this amplifier 47.
  • the differential unit 43 comprises an amplifier 47 in a differential arrangement and a network of four resistors of the same value.
  • a first resistor R1 is connected between the positive input of amplifier 47 and a ground electrode.
  • a second resistor R2 is connected between the positive input of the amplifier 47 and the output of the amplifier 46.
  • a third resistor is connected between the negative input of the amplifier 47 and the output of the low-pass filter 42.
  • a fourth resistor R4 is connected between the negative input of the amplifier 47 and its output terminal.
  • the output of the differential block 43 is connected to an amplifier 44 having a high gain.
  • the determination block 41 is able to measure the total current supplying all the emitters of a column, including the drain current passing through the modulator 14 during programming thereof. This drain current then appears across the resistor 45 in the form of a current pulse.
  • the output voltage of the determination block 41 is proportional to the total current flowing through the line 4. This voltage is applied across the low-pass filter 42 which eliminates the high frequency component. This high frequency component corresponds to the current pulse generated by the modulator 14 fed by the line 4 and which is during a programming step.
  • the amplifier 47 of the differential unit receives at its negative input a voltage proportional to the total supply current of the line 4, except the component corresponding to the drain current passing through the modulator 14, and on its positive input a voltage proportional to the total current in line 4. Since the resistors R1, R2, R3 and R4 are of the same value, the output voltage V diff of the differential unit 43 is equal to the resistance 45 multiplied by the drain current of the modulator 14 which is in the a programming step. This voltage is amplified by the amplifier 44 and is then compared with the data voltage U c in the comparison block 28 as explained above.
  • the image display device is a voltage control circuit of the modulators.
  • the DC generator 30 is then replaced by a voltage supply generator and preferably by a ramp voltage generator.
  • the amplitude of the ramp voltage is modulated according to the value of the amplitude of the data setpoint, transmitted by the column control driver 22.
  • the duration of the ramp voltage addressed to the addressing circuits 6 is also modulated according to the trigger threshold voltage V th , by the comparison means 28 and the control unit 34.
  • the four graphs of Figures 3A to 3D represent the addressing steps of an emitter when this is carried out by the display device according to the invention.
  • steps comprise a step A of initialization of an addressing circuit 6, an intermediate step B, a programming step C thereof and a light emission step D proportional to the previously programmed control current I data. .
  • the line driver 20 applies a select voltage V to the electrode 8 of the selected line. This voltage is applied to the gate of the switches 16, connected to the line electrode 8.
  • the control unit 34 of the external controller 24 of a column controls the closing of the switch 40 and a voltage V init generated by the generator 38, is applied to the addressing electrode 10 of this column.
  • the voltage V init is applied to a terminal of the storage capacitor 18 to discharge it, the switch 16 being closed.
  • Intermediate step B is short-lived and its sole function is to create a dead time to separate the initialization and programming steps in order to avoid short circuits.
  • the column control driver 22 emits a data voltage U c
  • the control unit 34 controls the closing of the switch 32 and the control generator 30 generates a control current I data . Since the switch 16 is closed, the current I data generates a potential difference between the gate and the source of the modulator 14.
  • the intensity of this drain current I d which corresponds to a part of the current flowing in line 4, is measured by the measurement unit 26 and a voltage representative of this drain current is compared with the data voltage U c 22.
  • the amplitude of the intensity of this current is compared with the intensity of the drain current.
  • the drain current generated passes through the emitter 2 which lights up.
  • the generator V dd powers the transmitter 2.
  • the comparison unit 28 compares the data voltage U c with the voltage representative of the amplitude of the drain current I d . As visible on the 3D figure , the amplitude of the drain current increases quadratic depending on the voltage between the gate and the source of the modulator. Little by little, the driving current I data generated by the generator 30 causes an accumulation of charges in the storage capacitor 18 connected to the gate of the modulator 14. This accumulation of charges causes increased voltage V gs between the gate and the source of the modulator 14 and consequently, the progressive increase of the drain current I d .
  • the duration of the programming step is variable and depends on the tripping threshold of each current modulator of the column.
  • the addressing signal of each transmitter is therefore modulated in duration as a function of the trigger threshold voltages.
  • the current I data is of the order of a few micro-amps so that the storage capacity 18 and the parasitic capacitances generated by the structure of the display panel are quickly loaded. Since the current I data is approximately 4 times greater than the drain current I d , the programming time is short, approximately of the order of a few micros seconds ( ⁇ s).
  • the storage capacity 18 has been sufficiently charged so that the transmitter 2 continues to transmit after its addressing during the duration of the image frame, always being powered from the generator V dd .
  • the duration of addressing of the driving current I data corresponding to the duration of closing of the switch 32 is both a function of the triggering threshold voltage V th of the modulator 14 selected and the value of the setpoint I data. .
  • the compensation means 12 of the tripping threshold are able to modulate the duration of the control signal I data in turn for each modulator of the transmitter column.
  • Step D begins at the end of the programming step and ends at the end of the selection of the line 8.
  • the transmitter 2 is still selected but its programming is complete; it continues to transmit according to this programming thanks to the voltage stored at the terminals of the capacitor 28.
  • the drain current I d continues to through the modulator 14 and the transmitter 2 until the voltage across the storage capacity 18 is discharged during a new step A initialization of this addressing circuit.
  • the control pilots 20, 22 and the compensation means 12 are used to program another circuit.
  • the first transmitter 2 continues to transmit.
  • the generator V dd which supplied power to the transmitter 2 during the programming step C continues to supply it as long as the gate voltage of the modulator 14 is greater than its trigger threshold voltage.
  • the figure 4 represents an alternative embodiment of the invention in which the control means 3 are identical to those shown in FIG. figure 1 .
  • the addressing circuit 6 driving a light emitter 2 of conventional structure is replaced by an addressing circuit 66 driving a so-called inverted structure light emitter.
  • the cathode of the emitters 52 forms the interface with the active matrix and the anode of the emitters 52 is connected to the power supply generator V dd .
  • the source of the modulator 54 is connected to a ground or a negative voltage generator.
  • the cathode of the transmitter 52 is connected to the drain of the modulator 54.
  • the storage capacitor 58 is connected between the gate and the source of the modulator 54.
  • a switch 56 is addressed in current I data by an addressing electrode 60 and is selected by a selection electrode 68.
  • the power supply generator V dd is directly connected to all emitters 52 of all the columns without the interposition of a switching unit. As a result, this generator V dd powers all the emitters 52 during the programming step C and during the step D throughout the duration of the image frame. Consequently, it is the power supply means V ss which are connected separately to the compensation means 12.
  • the supply means are directly connected to each modulator or directly connected to each emitter of a column, the electrical diagram of the display device is simplified and technically more easily achievable.
  • each power supply generator V ss is capable of supplying all the emitters 52 of a column and each addressing electrode 60 is also able to address all the emitters 52 of a column, the means compensation 12 are able to successively compensate the trigger threshold voltage V th of all the modulators 14 of a column.
  • the compensation means 12 determine the duration of the signal before each frame, the variations of the tripping threshold related to the aging of the modulators are automatically compensated.
  • no switching unit is interposed between the generator V dd or V ss and the modulator 14 or the transmitter 52 to switch between two power supply sources of the transmitter during the programming and transmission process. This one. As a result, the useful light emitting area of the pixels is increased.
  • control means are simplified and their implementation is facilitated.
  • the compensation means of all the columns compensate for the dispersions of the trigger threshold voltages of the control circuit modulators of an active matrix screen.
  • the unit 26 for measuring the current passing through a modulator during a programming step C makes it possible to dispense with a switching unit associated with each transmitter.
  • the intensity of the driving current I data is high, the parasitic capacitances generated by the addressing column of the display panel are quickly loaded. As a result, the display device is addressed instantly.

Abstract

The invention relates to an active-matrix display device which comprises: an array of light emitters, each emitter being supplied by power supply means; a current modulator having a trip-threshold voltage, said modulator being able to be addressed by applying a data setpoint to one of its terminals and a drain current being able to flow through said modulator in order to control said emitter; and trip-threshold voltage compensation means comprising a comparator for comparing the value of the drain current with the value of the data setpoint during a programming step. The power supply means for the emitters are capable of supplying the emitters during the programming step.

Description

La présente invention concerne un dispositif d'affichage d'images à matrice active.The present invention relates to an active matrix image display device.

Les écrans plats sont de plus en plus utilisés dans toutes sortes d'applications telles que dans des dispositifs d'affichage de véhicule automobile, dans des appareils photos numériques ou dans des téléphones portables. Il est connu des afficheurs dans lesquels les émetteurs de lumière sont formés à partir de cellules organiques électroluminescentes tels que les afficheurs OLED (Organic Light Emitting Diodes).Flat screens are increasingly used in all kinds of applications such as in motor vehicle display devices, in digital cameras or in mobile phones. There are known displays in which the light emitters are formed from organic electroluminescent cells such as OLED (Organic Light Emitting Diodes) displays.

En particulier, les afficheurs de type OLED à matrice passive sont déjà largement commercialisés. Cependant, ils consomment beaucoup d'énergie électrique et ont une durée de vie réduite.In particular, passive matrix OLED displays are already widely marketed. However, they consume a lot of electrical energy and have a reduced life.

Les afficheurs OLED à matrice active comportent une électronique intégrée, et présentent de nombreux avantages tels qu'une consommation réduite, une haute résolution, une compatibilité avec les cadences vidéo et une durée de vie plus longue que les afficheurs OLED à matrice passive.Active Matrix OLED displays have built-in electronics, and have many benefits such as reduced power consumption, high resolution, compatibility with video rates, and longer life than passive matrix OLED displays.

Classiquement, les dispositifs d'affichage comprennent un panneau de visualisation formé notamment par un réseau d'émetteurs de lumière. Chaque émetteur de lumière est lié à un pixel ou à un sous-pixel d'une image à visualiser et est adressé par un réseau d'électrodes de colonne et d'électrodes de ligne via un circuit d'adressage.Conventionally, the display devices comprise a display panel formed in particular by a network of light emitters. Each light emitter is linked to a pixel or a subpixel of an image to be displayed and is addressed by an array of column electrodes and line electrodes via an addressing circuit.

Les circuits d'adressage comprennent notamment des modulateurs de courant aptes à piloter le courant traversant les émetteurs et donc la luminance de chaque sous-pixel du panneau d'affichage.The addressing circuits include current modulators capable of driving the current flowing through the emitters and therefore the luminance of each sub-pixel of the display panel.

Dans une matrice active, ces modulateurs sont des transistors à couches minces, appelés transistors TFT (Thin Film Transistor), fabriqués en poly-Silicium cristallin selon la technologie du silicium poly cristallin basse température (LTPS). Cependant, cette technique introduit des variations spatiales locales de la tension de seuil de déclenchement des transistors à couches minces. Ces variations sont dues au fait que les joints et les dimensions des grains du poly-Silicium ne sont pas suffisamment maîtrisables pendant la phase de cristallisation du Silicium amorphe en Silicium poly-cristallin. Ainsi, les transistors TFT composant un même panneau d'affichage, présentent des tensions de seuil de déclenchement différentes.In an active matrix, these modulators are thin-film transistors, called Thin Film Transistor (TFT) transistors, made of crystalline poly-silicon using low-temperature polycrystalline silicon (LTPS) technology. However, this technique introduces local spatial variations in the threshold threshold voltage of thin-film transistors. These variations are due to the fact that the seams and grain size of the poly-silicon are not sufficiently controllable during the crystallization phase of amorphous silicon in polycrystalline silicon. Thus, the TFT transistors comprising the same display panel have different trigger threshold voltages.

En conséquence, les transistors TFT alimentés par la même tension d'alimentation et commandés par des tensions ou des courants de données identiques génèrent des courants d'intensité différente.As a result, TFT transistors fed by the same supply voltage and controlled by identical data voltages or currents generate currents of different intensity.

Or, comme un émetteur émet généralement une intensité lumineuse directement proportionnelle au courant qui le traverse, l'hétérogénéité des seuils de déclenchement des transistors en poly-Silicium cristallin entraîne une non uniformité de brillance d'un écran constitué par une matrice de tels transistors. Il en résulte des différences entre les niveaux de luminance et un inconfort visuel manifeste pour l'utilisateur.However, since an emitter generally emits a light intensity directly proportional to the current flowing through it, the heterogeneity of the trigger thresholds of the crystalline poly-silicon transistors causes non-uniformity of brightness of a screen formed by a matrix of such transistors. This results in differences in luminance levels and obvious visual discomfort for the user.

Pour compenser les tensions de seuil de déclenchement des transistors TFT d'une matrice active, il est connu notamment par le document US 6,433,488 , un circuit de commande d'un émetteur comprenant une unité de comparaison apte à comparer le courant de drain Id traversant le modulateur à un courant de référence pendant une étape de programmation du circuit de commande. Cependant, ce circuit nécessite l'implantation d'une unité de commutation par émetteur pour commuter la source d'alimentation de l'émetteur entre l'étape de programmation et une étape de fin trame d'émission de l'émetteur. Cette unité de commutation comprend deux transistors à couches minces et un amplificateur inverseur. Ce circuit est difficile à fabriquer et peu économique.To compensate for the trigger threshold voltages of the TFT transistors of an active matrix, it is known in particular from the document US 6,433,488 A control circuit of a transmitter comprising a comparison unit adapted to compare the drain current I d flowing through the modulator to a reference current during a programming step of the control circuit. However, this circuit requires the implementation of a switching unit by transmitter to switch the power source of the transmitter between the programming step and a transmitter transmission end stage. This switching unit comprises two thin film transistors and an inverting amplifier. This circuit is difficult to manufacture and not very economical.

Il est connu notamment par le document EP 1 381 019 des dispositifs d'affichage à matrice active comprenant des émetteurs OLED, des moyens d'alimentation des émetteurs, des modulateurs et des moyens de compensation des tensions de seuil de déclenchement des modulateurs. Les moyens de compensation comprennent des moyens de comparaison du courant de drain traversant un émetteur sélectionné à une consigne d'affichage.He is known in particular by the document EP 1 381 019 active matrix display devices comprising OLED transmitters, transmitter power supply means, modulators and means for compensation of the tripping threshold voltages of the modulators. The compensation means comprise means for comparing the drain current passing through a selected transmitter to a display setpoint.

Toutefois, dans ces dispositifs d'affichage, les émetteurs ne sont pas alimentés par les mêmes moyens d'alimentation à la fois pendant les phases de programmation et les phases d'émission qui se succèdent pour l'affichage des images, ce qui nécessite un réseau d'électrodes spécifique pour chaque mode d'alimentation.However, in these display devices, the transmitters are not powered by the same power supply means both during the programming phases and the successive transmission phases for the display of the images, which requires a specific electrode array for each power mode.

Il est connu notamment par le document JP-2002/278513 un dispositif d'affichage comprenant des émetteurs OLED, des moyens d'alimentation des émetteurs, des modulateurs et des moyens de compensation des tensions de seuil de déclenchement des modulateurs. Les émetteurs sont alimentés par les mêmes moyens d'alimentation à la fois pendant les phases de programmation et les phases d'émission qui se succèdent pour l'affichage des images, mais la compensation des tensions de seuil est effectuée lors d'une phase de calibration préalable à l'affichage des images. Les moyens de compensation comprennent des moyens de mesure du courant de drain traversant un émetteur sélectionné et des moyens de comparaison de ce courant de drain à une consigne de calibrage de cet émetteur. Ces moyens de compensation ne permettent donc pas d'assurer la compensation de variations de tensions de seuil de déclenchement qui apparaîtraient en cours de phase d'affichage des images.He is known in particular by the document JP-2002/278513 a display device comprising OLED transmitters, transmitter power supply means, modulators and voltage compensation means, tripping threshold of modulators. The emitters are fed by the same power supply means during the programming phases and the successive transmission phases for the display of the images, but the compensation of the threshold voltages is carried out during a phase of calibration prior to displaying the images. The compensation means comprise means for measuring the drain current passing through a selected transmitter and means for comparing this drain current to a calibration setpoint of this emitter. These compensation means therefore do not make it possible to compensate for variations in triggering threshold voltages that would appear during the display phase of the images.

Il est connu notamment par le document JP-2002/091377 , US-2003/001832 et WO-2004/034364 , des dispositifs d'affichage à matrice active comprenant des émetteurs OLED, des modulateurs et des moyens de compensation des tensions de seuil de déclenchement des modulateurs. Les moyens de compensation comprennent des moyens de mesure du courant de drain traversant un émetteur sélectionné et des moyens de comparaison de ce courant de drain à une consigne d'affichage. Toutefois, les moyens de mesure du courant de drain sont propres à chaque émetteur d'une colonne. Par exemple dans le document WO-20041034364 , ils comprennent une résistance, deux électrodes et deux interrupteurs pour chaque émetteur d'une colonne. Cette architecture est par conséquent complexe et coûteuse.He is known in particular by the document JP-2002/091377 , US-2003/001832 and WO-2004/034364 , active matrix display devices comprising OLED transmitters, modulators and means for compensating tripping threshold voltages of the modulators. The compensation means comprise means for measuring the drain current passing through a selected transmitter and means for comparing this drain current with a display setpoint. However, the means for measuring the drain current are specific to each emitter of a column. For example in the document WO 20041034364 they comprise a resistor, two electrodes and two switches for each emitter of a column. This architecture is therefore complex and expensive.

Un but de la présente invention est la mise en oeuvre d'un circuit de commande moins complexe et donc moins onéreux.An object of the present invention is the implementation of a control circuit less complex and therefore less expensive.

A cet effet, la présente invention a pour objet un dispositif d'affichage d'images à matrice active comprenant :

  • plusieurs émetteurs de lumière formant un réseau d'émetteurs répartis en lignes et en colonnes ;
  • des moyens d'alimentation en puissance aptes à alimenter en courant simultanément l'ensemble des émetteurs d'une colonne
  • des moyens de commande de l'émission des émetteurs comprenant :
  • pour chaque émetteur du réseau, un modulateur de courant comportant une électrode de source, une électrode de drain, une électrode de grille, ledit modulateur étant apte à être traversé par un courant de drain pour alimenter ledit émetteur, pour une tension entre le drain ou la source et la grille supérieure ou égale à une tension de seuil de déclenchement ;
  • pour chaque colonne d'émetteurs, des moyens d'adressage de colonne aptes à adresser successivement chaque émetteur de ladite colonne d'émetteurs par application d'une valeur représentative d'une consigne de données à l'électrode de grille du modulateur associé à cet émetteur, pour le commander, au cours d'une étape de programmation,
  • pour chaque ligne d'émetteurs, des moyens de sélection de ligne aptes à sélectionner successivement les émetteurs de chaque ligne d'émetteurs, pendant l'étape de programmation,
  • pour chaque modulateur, des moyens de stockage aptes à stocker des charges électriques à l'électrode de grille du modulateur, et
  • des moyens de compensation des tensions de seuil de déclenchement comprenant des moyens de comparaison, les moyens de comparaison étant aptes à comparer, pendant l'étape de programmation d'un émetteur sélectionné, une valeur représentative du courant de drain alimentant l'émetteur sélectionné à la valeur représentative de la consigne de données, pour commander la quantité de charges stockées sur les moyens de stockage,
caractérisé en ce que les moyens de compensation comprennent pour chaque colonne d'émetteurs une unique unité de détermination d'une valeur représentative du courant de drain alimentant l'émetteur sélectionné à partir d'une mesure d'une valeur représentative du courant d'alimentation de l'ensemble des émetteurs de la colonne qui restent alimentés par les mêmes moyens d'alimentation à la fois pendant les phases de programmation et les phases d'émission.For this purpose, the present invention relates to an active matrix image display device comprising:
  • several light emitters forming a network of transmitters distributed in rows and columns;
  • power supply means capable of simultaneously supplying all the emitters of a column
  • transmitter emission control means comprising:
  • for each transmitter of the network, a current modulator comprising a source electrode, a drain electrode, a gate electrode, said modulator being able to be traversed by a drain current for supplying said transmitter for a voltage between the drain or source and the gate greater than or equal to a trigger threshold voltage;
  • for each column of transmitters, column addressing means capable of successively addressing each transmitter of said column of transmitters by applying a value representative of a data setpoint to the gate electrode of the modulator associated with this transmitter, to control it, during a programming step,
  • for each line of transmitters, line selection means capable of successively selecting the transmitters of each line of transmitters, during the programming step,
  • for each modulator, storage means able to store electrical charges at the gate electrode of the modulator, and
  • means for compensating the trigger threshold voltages comprising comparison means, the comparison means being able to compare, during the programming step of a selected transmitter, a value representative of the drain current supplying the selected transmitter to the representative value of the data setpoint, for controlling the quantity of charges stored on the storage means,
characterized in that the compensation means comprise for each column of transmitters a single unit for determining a value representative of the drain current supplying the selected transmitter from a measurement of a value representative of the supply current of all the column transmitters that remain powered by the same power supply means both during the programming phases and the transmission phases.

Suivant des modes particuliers de réalisation, le dispositif d'affichage comporte une ou plusieurs des caractéristiques suivantes :

  • les moyens d'alimentation en puissance des émetteurs sont directement connectés à chaque modulateur des moyens de commande ;
  • les moyens d'alimentation en puissance des émetteurs sont directement connectés à chaque émetteur d'une colonne ;
  • les moyens d'alimentation en puissance des émetteurs comprennent un générateur d'alimentation en tension apte à alimenter l'ensemble des émetteurs d'une colonne, et les moyens de compensation sont aptes à compenser successivement la tension de seuil de déclenchement de chaque modulateur de l'ensemble des émetteurs d'une colonne ;
  • les moyens de compensation comprennent en outre:
  • un générateur de pilotage apte à générer un signal de pilotage appliqué à la grille dudit modulateur ;
  • des moyens de modulation de la durée dudit signal de pilotage en fonction de la valeur de la consigne de données et de la valeur de la tension de seuil de déclenchement ;
  • la consigne de données est une tension de données et les moyens de comparaison sont aptes à émettre un signal d'avertissement lorsque la tension représentative de l'intensité du courant de drain est égale à un nombre de fois ladite tension de données ;
  • les moyens de modulation de la durée du signal de pilotage comprennent :
  • un interrupteur connecté en série au générateur de pilotage ;
  • une unité de contrôle apte à la commuter ledit interrupteur d'une part lors de la réception de la consigne de données et, d'autre part lors de la réception du signal d'avertissement ;
  • le signal de pilotage généré par le générateur de pilotage est modulé en amplitude en fonction de la valeur de la consigne de données ;
  • le générateur de pilotage est un générateur de courant et le modulateur est apte à être piloté en courant ;
  • le générateur de pilotage est un générateur de tension en rampe et le modulateur est apte à être piloté en tension ;
  • les moyens de compensation comprennent en outre une unité de mesure de l'intensité d'un courant apte à mesurer l'intensité du courant de drain traversant un émetteur sélectionné au cours de l'étape de programmation ;
  • les moyens d'alimentation comprennent une ligne à laquelle l'unité de mesure est directement raccordée ; et
  • les moyens de stockage comprennent au moins une capacité de stockage reliée à la grille et à la source du modulateur, et les moyens de compensation comprennent en outre des moyens d'initialisation aptes à appliquer une impulsion de tension à ladite capacité pour la décharger.
According to particular embodiments, the display device comprises one or more of the following characteristics:
  • the power supply means of the emitters are directly connected to each modulator of the control means;
  • the power supply means of the emitters are directly connected to each emitter of a column;
  • the power supply means of the emitters comprise a voltage supply generator capable of supplying all the emitters of a column, and the compensation means are capable of successively compensating the trigger threshold voltage of each modulator of all the issuers of a column;
  • the compensation means furthermore comprise:
  • a control generator adapted to generate a control signal applied to the gate of said modulator;
  • means for modulating the duration of said control signal as a function of the value of the data setpoint and the value of the triggering threshold voltage;
  • the data setpoint is a data voltage and the comparison means are able to emit a warning signal when the voltage representative of the intensity of the drain current is equal to a number of times said data voltage;
  • the means for modulating the duration of the piloting signal comprise:
  • a switch connected in series to the control generator;
  • a control unit able to switch said switch on the one hand when receiving the data set and on the other hand when receiving the warning signal;
  • the control signal generated by the control generator is modulated in amplitude as a function of the value of the data set;
  • the control generator is a current generator and the modulator is able to be driven by current;
  • the control generator is a ramp voltage generator and the modulator is able to be controlled in voltage;
  • the compensation means further comprise a unit for measuring the intensity of a current capable of measuring the intensity of the drain current flowing through a selected transmitter during the programming step;
  • the supply means comprise a line to which the measurement unit is directly connected; and
  • the storage means comprise at least one storage capacity connected to the gate and the source of the modulator, and the compensation means further comprise initialization means adapted to apply a voltage pulse to said capacity to discharge it.

L'invention sera mieux comprise à la lecture de la description qui va suivre, donnée à titre d'exemple non limitatif et, faite en référence aux figures annexées sur lesquelles :

  • la figure 1 est un schéma synoptique d'un circuit de commande et d'alimentation d'un émetteur selon l'invention ;
  • la figure 2 est un schéma synoptique d'un exemple de réalisation d'une unité de mesure de courant selon l'invention ;
  • les figures 3A à 3D sont des graphes représentant l'évolution au cours du temps de différents tensions et courants au cours du processus réalisé par le dispositif selon l'invention ; en particulier
  • la figure 3A est un graphe représentant la tension de sélection appliquée à l'électrode de sélection ;
  • la figure 3B est un graphe représentant la tension appliquée à l'électrode d'adressage par les moyens d'initialisation ;
  • la figure 3C est un graphe représentant le signal d'avertissement généré par l'unité de comparaison ;
  • la figure 3D est un graphe représentant l'évolution du courant de drain et du courant de pilotage ; et
  • la figure 4 est un schéma synoptique d'un circuit d'adressage selon une variante de réalisation de l'invention.
The invention will be better understood on reading the description which follows, given by way of nonlimiting example and with reference to the appended figures in which:
  • the figure 1 is a block diagram of a control circuit and power supply of a transmitter according to the invention;
  • the figure 2 is a block diagram of an exemplary embodiment of a current measurement unit according to the invention;
  • the Figures 3A to 3D are graphs representing the evolution over time of different voltages and currents during the process performed by the device according to the invention; in particular
  • the figure 3A is a graph representing the selection voltage applied to the selection electrode;
  • the figure 3B is a graph representing the voltage applied to the addressing electrode by the initialization means;
  • the figure 3C is a graph representing the warning signal generated by the comparison unit;
  • the 3D figure is a graph representing the evolution of the drain current and the driving current; and
  • the figure 4 is a block diagram of an addressing circuit according to an alternative embodiment of the invention.

La figure 1 représente un dispositif d'affichage à matrice active selon l'invention. Un tel dispositif comprend une pluralité d'émetteurs 2 de lumière formant un réseau de lignes et de colonnes, des moyens d'alimentation en puissance Vdd des émetteurs 2 et des moyens de commande 3 d'émission des émetteurs. Cependant, par souci de simplification, un seul émetteur et un seul moyen d'alimentation ont été représentés sur la figure 1.The figure 1 represents an active matrix display device according to the invention. Such a device comprises a plurality of light emitters 2 forming a network of rows and columns, power supply means V dd of the emitters 2 and transmitter transmission control means 3. However, for the sake of simplification, only one transmitter and one power supply have been represented on the figure 1 .

Les émetteurs 2 du panneau de visualisation sont des diodes électroluminescentes organiques. Ils comprennent une anode et une cathode. Ils sont chacun associés à un pixel lorsque le panneau est monochrome ou à un sous pixel lorsque le panneau de visualisation est polychrome. Ils émettent une intensité lumineuse directement proportionnelle au courant qui les traverse.The emitters 2 of the display panel are organic electroluminescent diodes. They include an anode and a cathode. They are each associated with a pixel when the panel is monochrome or a sub pixel when the display panel is full color. They emit a luminous intensity directly proportional to the current passing through them.

Les moyens d'alimentation en puissance Vdd des émetteurs 2 comprennent un générateur de tension continue par colonne d'émetteurs 2. Ce générateur Vdd alimente une ligne 4, à laquelle est connecté l'ensemble des émetteurs 2 de cette colonne.The power supply means V dd of the transmitters 2 comprise a DC voltage generator per column of transmitters 2. This generator V dd feeds a line 4, to which is connected all the emitters 2 of this column.

Les moyens de commande 3 du dispositif d'affichage comprennent un circuit d'adressage 6 pour chaque émetteur, un réseau d'électrodes de sélection 8 de ligne et d'adressage 10 de colonne et des moyens de compensation 12 du seuil du déclenchement des modulateurs.The control means 3 of the display device comprise an addressing circuit 6 for each transmitter, an array of selection electrodes 8 of line and column addressing and compensation means 12 of the tripping threshold modulators.

Un circuit d'adressage 6 est connecté à chaque émetteur 2 du panneau de visualisation. Le circuit d'adressage représenté sur la figure 1 est un circuit de structure classique. Dans ce type de circuit, l'anode de l'émetteur forme l'interface avec la matrice active et la cathode de l'émetteur est connectée à une électrode de masse ou à une tension négative.An addressing circuit 6 is connected to each transmitter 2 of the display panel. The addressing circuit represented on the figure 1 is a classic structure circuit. In this type of circuit, the anode of the emitter forms the interface with the active matrix and the cathode of the emitter is connected to a ground electrode or a negative voltage.

Le circuit d'adressage 6 comprend un modulateur de courant 14, un interrupteur 16 et une capacité de stockage 18.The addressing circuit 6 comprises a current modulator 14, a switch 16 and a storage capacitor 18.

Le modulateur de courant 14 est un transistor basé sur une technologie utilisant du Silicium poly-cristallin (Poly-Si) ou du Silicium amorphe (a-Si) déposé en couches minces sur un substrat de verre. De tels composants comprennent trois électrodes: une électrode de drain et une électrode de source entre lesquelles circule le courant modulé, et une électrode de grille à laquelle est appliqué un courant de pilotage de données Idata.The current modulator 14 is a transistor based on a technology using polycrystalline silicon (Poly-Si) or amorphous silicon (a-Si) deposited in thin layers on a glass substrate. Such components comprise three electrodes: a drain electrode and a source electrode between which the modulated current flows, and a gate electrode to which a data driving current I data is applied.

Les transistors en couches minces (Thin Film Transistor en anglais) sont de type n ou p. Le modulateur 14 représenté sur la figure 1 est de type p. Sa source est connectée directement à l'électrode d'alimentation Vdd et son drain est relié directement à l'anode de l'émetteur 2 de sorte que en fonctionnement le courant électrique modulé circule entre la source et le drain. Alternativement, lorsque le modulateur 14 est de type n, le drain est connecté à l'électrode d'alimentation Vdd et le courant électrique modulé circule alors entre le drain et la source.The thin film transistors (Thin Film Transistor) are of type n or p. The modulator 14 shown on the figure 1 is of type p. Its source is connected directly to the supply electrode V dd and its drain is connected directly to the anode of the emitter 2 so that in operation the modulated electric current flows between the source and the drain. Alternatively, when the modulator 14 is of type n, the drain is connected to the supply electrode V dd and the modulated electric current then flows between the drain and the source.

Le générateur d'alimentation en puissance Vdd est directement connecté à l'ensemble des modulateurs 14 de commande des émetteurs d'une colonne, de sorte qu'il est toujours apte à alimenter un émetteur 2 sélectionné et adressé quelque soit l'étape du processus d'émission d'une trame d'image. Ainsi, dès qu'un modulateur 14 de la colonne est débloqué par application d'une tension d'adressage et de sélection, l'émetteur correspondant est alimenté par le seul générateur Vdd.The power supply generator V dd is directly connected to all the modulators 14 for controlling the emitters of a column, so that it is always able to power a transmitter 2 selected and addressed whatever the step of process of transmitting an image frame. Thus, as soon as a modulator 14 of the column is unblocked by applying an addressing and selection voltage, the corresponding transmitter is powered by the single generator V dd .

L'interrupteur 16 est également un transistor basé sur la technologie utilisant du Silicium poly-cristallin (Poly-Si) ou du Silicium amorphe (a-Si) déposé en couches minces. L'une de ses électrodes (drain ou source) est reliée à l'électrode d'adressage 10 et l'autre électrode (drain ou source) est reliée à la grille du modulateur 14. Sa grille est connectée à l'électrode 8 de sélection de ligne.The switch 16 is also a technology-based transistor using polycrystalline silicon (Poly-Si) or amorphous silicon (a-Si) deposited in thin layers. One of its electrodes (drain or source) is connected to the addressing electrode 10 and the other electrode (drain or source) is connected to the gate of the modulator 14. Its gate is connected to the electrode 8 of line selection.

La capacité de stockage 18 est disposée entre la grille et la source du modulateur 14 pour maintenir la brillance de l'émetteur 2 pendant une durée de trame d'image. Cette capacité est adaptée pour maintenir sensiblement la tension constante sur la grille du modulateur 14 pendant un intervalle de temps correspondant à la durée de trame.The storage capacitor 18 is disposed between the gate and the source of the modulator 14 to maintain the brightness of the transmitter 2 during an image frame duration. This capacitance is adapted to substantially maintain the constant voltage on the gate of the modulator 14 during a time interval corresponding to the frame duration.

Le réseau d'électrodes de sélection 8 et d'adressage 10 permet de sélectionner et d'adresser un émetteur spécifique parmi l'ensemble des émetteurs du panneau de visualisation.The array of selection electrodes 8 and addressing 10 makes it possible to select and address a specific transmitter among all the transmitters of the display panel.

Chaque électrode 8 de sélection est reliée à la grille des interrupteurs 16 d'une ligne et est apte à transmettre une tension de sélection Vselect à l'ensemble des émetteurs 2 de cette ligne. La tension de sélection Vselect est une donnée logique de sélection des émetteurs.Each selection electrode 8 is connected to the gate of the switches 16 of a line and is able to transmit a selection voltage V select to all the emitters 2 of this line. The selection voltage V select is a logical data selection of the transmitters.

Chaque électrode 10 d'adressage est reliée à la source ou au drain des interrupteurs 16 d'une colonne et est apte à adresser un courant de pilotage de données Idata à la grille du modulateur 14 de l'ensemble des circuits d'adressage 6 de cette colonne en fonction d'une consigne de données Uc. Dans l'exemple de réalisation de l'invention représenté sur la figure 1, l'intensité de courant passant dans l'émetteur est proportionnelle à l'amplitude du courant Idata qui est appliqué sur l'électrode 10.Each addressing electrode 10 is connected to the source or the drain of the switches 16 of a column and is able to address a data driving current I data to the gate of the modulator 14 of the set of addressing circuits 6 of this column according to a data set U c . In the exemplary embodiment of the invention shown in the figure 1 , the intensity of current flowing in the emitter is proportional to the amplitude of the current I data which is applied to the electrode 10.

Les électrodes de sélection 8 et d'adressage 10 sont chacune commandées par un pilote de commande correspondant 20, 22 pour appliquer des tensions de sélection Vselect et des consignes de données Uc aux émetteurs. Ainsi, en sélectionnant une seule électrode 8 de ligne du panneau et en activant uniquement le pilote 20 correspondant à cette ligne et en appliquant une consigne de données Uc à une électrode de colonne 10 de ce panneau, propre à appliquer un courant de pilotage Idata sur le modulateur 14, un unique émetteur au croisement de l'électrode de cette ligne 8 et de l'électrode 10 de cette colonne est apte à émettre de la lumière.The selection and addressing electrodes 10 are each controlled by a corresponding control driver 20, 22 for applying V select selection voltages and U c data instructions to the transmitters. Thus, by selecting a single line electrode 8 of the panel and activating only the driver 20 corresponding to this line and applying a data set U c to a column electrode 10 of this panel, suitable for applying a driving current I data on the modulator 14, a single transmitter at the intersection of the electrode of this line 8 and the electrode 10 of this column is able to emit light.

Les moyens de compensation 12 des seuils de déclenchement sont aptes à compenser les tensions de seuil de déclenchement Vth de l'ensemble des modulateurs 14 adressés par l'électrode 10 d'adressage de cette colonne.The compensation means 12 of the triggering thresholds are able to compensate for the triggering threshold volt V.sub.th of all the modulators 14 addressed by the addressing electrode 10 of this column.

Ils comprennent un contrôleur externe 24 par colonne d'émetteurs. Ce contrôleur comprend une unité de mesure 26, une unité de comparaison 28, un générateur de pilotage 30, un interrupteur 32, une unité de contrôle 34 et des moyens d'initialisation 36 des circuits d'adressage 6 de cette colonne.They include an external controller 24 per column of transmitters. This controller comprises a measurement unit 26, a comparison unit 28, a control generator 30, a switch 32, a control unit 34 and initialization means 36 of the addressing circuits 6 of this column.

L'unité de mesure 26 est connectée à l'électrode 4 d'alimentation en puissance de tous les émetteurs d'une colonne. L'unité de mesure 26 est apte à mesurer une valeur représentative du courant de drain Id d'un modulateur 14 sélectionné par l'électrode 8 de sélection et à la grille duquel un courant de pilotage Idata est appliqué.The measurement unit 26 is connected to the power supply electrode 4 of all the emitters of a column. The measurement unit 26 is able to measure a value representative of the drain current I d of a modulator 14 selected by the selection electrode 8 and the gate of which a driving current I data is applied.

Plus précisément, le rôle de l'unité 26 est d'extraire de la somme des courants mesurés dans la ligne 4, uniquement le courant du modulateur 14 en cours de programmation. Un exemple de réalisation de l'unité de mesure 26 sera décrit ci-après en liaison avec la figure 2.More specifically, the role of the unit 26 is to extract from the sum of the currents measured in the line 4, only the current of the modulator 14 being programmed. An exemplary embodiment of the measurement unit 26 will be described below in connection with the figure 2 .

L'unité de comparaison 28 comprend deux bornes d'entrée propres à recevoir la consigne de données Uc adressée par le pilote de commande 22 et une valeur représentative du courant de drain Id mesuré par l'unité de mesure 26.The comparison unit 28 comprises two input terminals adapted to receive the data set U c addressed by the control driver 22 and a value representative of the drain current I d measured by the measurement unit 26.

Dans l'exemple de réalisation de l'invention représenté sur la figure 1, la consigne de données Uc est une tension de données. L'unité de comparaison 28 est adaptée pour comparer l'amplitude de la tension représentative du courant de drain Id et l'amplitude de la tension de données Uc pendant une étape dite de programmation C du circuit d'adressage 6.In the exemplary embodiment of the invention shown in the figure 1 , the data set U c is a data voltage. The comparison unit 28 is adapted to compare the amplitude of the voltage representative of the drain current I d and the amplitude of the data voltage U c during a so-called programming step C of the addressing circuit 6.

De plus, l'unité de comparaison 28 comprend une borne de sortie apte à émettre un signal d'avertissement S lorsque l'amplitude de la tension représentative de l'intensité du courant de drain Id et l'amplitude de la tension de données Uc sont liées par un coefficient k de proportionnalité prédéterminé. Le signal d'avertissement S est un signal logique envoyé à l'unité de contrôle 34.In addition, the comparison unit 28 comprises an output terminal capable of transmitting a warning signal S when the amplitude of the voltage representative of the intensity of the drain current I d and the amplitude of the data voltage. U c are linked by a predetermined coefficient k of proportionality. The warning signal S is a logic signal sent to the control unit 34.

En variante, la consigne de données est une donnée numérique ou une intensité de données.In a variant, the data setpoint is a digital datum or a data intensity.

Le générateur de pilotage 30 est un générateur de courant continu propre à fournir un courant de pilotage Idata qui est fonction de la consigne de données Uc appliquée à ce générateur. Il est raccordé en série à l'électrode d'adressage 10. Il est apte à recevoir la tension de données Uc adressée par le pilote 22 de commande de colonne et à générer un courant de pilotage Idata dont l'amplitude est modulée en fonction de l'amplitude de la tension de données Uc.The control generator 30 is a DC generator capable of supplying a control current I data which is a function of the data setpoint Uc applied to this generator. It is connected in series with the addressing electrode 10. It is able to receive the data voltage U c addressed by the column control driver 22 and to generate a control current I data whose amplitude is modulated in depending on the amplitude of the data voltage U c .

L'interrupteur 32 est raccordé en série en sortie du générateur de pilotage 30. Il est apte à commuter entre une position de fermeture dans laquelle le courant de pilotage Idata, alimente l'électrode 10 d'adressage de l'ensemble des circuits d'adressage 6 de la colonne et une position ouverte dans laquelle les circuits d'adressage 6 ne sont pas adressés.The switch 32 is connected in series at the output of the control generator 30. It is able to switch between a closed position in which the control current I data supplies the addressing electrode of all the control circuits. addressing 6 of the column and an open position in which the addressing circuits 6 are not addressed.

L'unité de contrôle 34 est connectée au pilote 22, à la sortie du module de comparaison 28 et à l'interrupteur 32 pour recevoir la tension de données Uc et le signal d'avertissement S et pour commander la commutation de l'interrupteur 32. L'unité de contrôle 34 est apte à commander la fermeture de l'interrupteur 32 sur réception de la tension de données Uc et l'ouverture de celui-ci sur réception du signal d'avertissement S. Ainsi, la durée du courant de pilotage Idata généré, est modulée en fonction de la tension de seuil de déclenchement Vth propre à chaque modulateur 14 comme cela sera expliqué dans la suite.The control unit 34 is connected to the driver 22, to the output of the comparison module 28 and to the switch 32 to receive the data voltage U c and the warning signal S and to control the switching of the switch 32. The control unit 34 is able to control the closing of the switch 32 on receipt of the data voltage U c and the opening thereof on receipt of the warning signal S. Thus, the duration of the driving current I data generated is modulated depending on the threshold voltage V th unique to each modulator 14 as will be explained hereinafter.

Les moyens d'initialisation 36 des circuits d'adressage 6 sont connectés en parallèle au générateur 30 pour que l'image d'une trame ne soit pas influencée par l'image de la trame précédente. Ils sont aptes à émettre une tension carrée pour décharger la capacité de stockage 18 et une capacité parasite induite par le panneau de visualisation. Ils comprennent un générateur 38 de tension continue et un interrupteur 40. L'interrupteur 40 est relié à l'unité de contrôle 34. L'unité de contrôle 34 est connectée au pilote 20 pour commander la fermeture de l'interrupteur 40 sur réception de la tension de sélection Vselect.The initialization means 36 of the addressing circuits 6 are connected in parallel to the generator 30 so that the image of a frame is not influenced by the image of the previous frame. They are able to emit a square voltage to discharge the storage capacity 18 and a parasitic capacitance induced by the display panel. They comprise a DC voltage generator 38 and a switch 40. The switch 40 is connected to the control unit 34. The control unit 34 is connected to the driver 20 to control the closing of the switch 40 on receipt of the selection voltage V select .

Alternativement, le circuit d'adressage 6 comprend un interrupteur de shunt de la capacité de stockage 18.Alternatively, the addressing circuit 6 comprises a shunt switch of the storage capacity 18.

La figure 2 représente un exemple de réalisation d'une unité 26 de mesure d'une valeur représentative du courant de drain Id traversant le modulateur 14 du circuit de commande pour lequel l'étape de programmation débute.The figure 2 represents an embodiment of a unit 26 for measuring a value representative of the drain current I d flowing through the modulator 14 of the control circuit to which programming step begins.

Une telle unité de mesure 26 est connectée à la ligne 4 d'alimentation des émetteurs 2 d'une colonne. Elle comprend un bloc 41 de détermination du courant de drain Id, un filtre passe-bas 42, un bloc différentiel 43 et un amplificateur 44.Such a measurement unit 26 is connected to the supply line 4 of the emitters 2 of a column. It comprises a block 41 for determining the drain current I d , a low-pass filter 42, a differential block 43 and an amplifier 44.

Le bloc de détermination 41 comprend une résistance 45, par exemple de 1 à 10 kilos Ohms, connectée en série à la ligne 4 d'alimentation des émetteurs et un amplificateur opérationnel 46 de précision dont les bornes sont raccordées à la ligne d'alimentation 4 de part et d'autre de la résistance 45. La sortie de l'amplificateur 46 est connectée d'une part au filtre passe -bas 42, lui-même connecté à une borne négative d'un amplificateur 47 du bloc différentiel 43 et d'autre part à une borne positive de cet amplificateur 47.The determination block 41 comprises a resistor 45, for example from 1 to 10 kilos Ohms, connected in series with the supply line 4 of the transmitters and a precision operational amplifier 46 whose terminals are connected to the supply line 4 on either side of the resistor 45. The output of the amplifier 46 is connected on the one hand to the low-pass filter 42 , itself connected to a negative terminal of an amplifier 47 of the differential block 43 and secondly to a positive terminal of this amplifier 47.

Le bloc différentiel 43 comprend un amplificateur 47 dans un montage différentiel et un réseau de quatre résistances de même valeur. Une première résistance R1 est raccordée entre l'entrée positive de l'amplificateur 47 et une électrode de masse. Une seconde résistance R2 est raccordée entre l'entrée positive de l'amplificateur 47 et la sortie de l'amplificateur 46. Une troisième résistance est raccordée entre l'entrée négative de l'amplificateur 47 et la sortie du filtre passe-bas 42. Enfin, une quatrième résistance R4 est raccordée entre l'entrée négative de l'amplificateur 47 et sa borne de sortie. De plus, la sortie du bloc différentiel 43 est branchée à un amplificateur 44 ayant un gain élevé.The differential unit 43 comprises an amplifier 47 in a differential arrangement and a network of four resistors of the same value. A first resistor R1 is connected between the positive input of amplifier 47 and a ground electrode. A second resistor R2 is connected between the positive input of the amplifier 47 and the output of the amplifier 46. A third resistor is connected between the negative input of the amplifier 47 and the output of the low-pass filter 42. Finally, a fourth resistor R4 is connected between the negative input of the amplifier 47 and its output terminal. In addition, the output of the differential block 43 is connected to an amplifier 44 having a high gain.

Le bloc de détermination 41 est apte à mesurer le courant total alimentant l'ensemble des émetteurs d'une colonne, y compris le courant de drain traversant le modulateur 14 pendant la programmation de celui-ci. Ce courant de drain apparaît alors aux bornes de la résistance 45 sous la forme d'une impulsion de courant. La tension de sortie du bloc de détermination 41 est proportionnelle au courant total traversant la ligne 4. Cette tension est appliquée aux bornes du filtre passe-bas 42 qui en élimine la composante haute fréquence. Cette composante haute fréquence correspond à l'impulsion du courant générée par le modulateur 14 alimenté par la ligne 4 et qui est au cours d'une étape de programmation.The determination block 41 is able to measure the total current supplying all the emitters of a column, including the drain current passing through the modulator 14 during programming thereof. This drain current then appears across the resistor 45 in the form of a current pulse. The output voltage of the determination block 41 is proportional to the total current flowing through the line 4. This voltage is applied across the low-pass filter 42 which eliminates the high frequency component. This high frequency component corresponds to the current pulse generated by the modulator 14 fed by the line 4 and which is during a programming step.

L'amplificateur 47 du bloc différentiel reçoit à son entrée négative une tension proportionnelle au courant total d'alimentation de la ligne 4, excepté la composante correspondant au courant de drain traversant le modulateur 14 et, sur son entrée positive une tension proportionnelle au courant total sur la ligne 4. Comme les résistances R1, R2, R3 et R4 sont de même valeur, la tension en sortie Vdiff du bloc différentiel 43 est égale à la résistance 45 multipliée par le courant de drain du modulateur 14 qui est au cours d'une étape de programmation. Cette tension est amplifiée par l'amplificateur 44 puis est comparée à la tension de données Uc dans le bloc de comparaison 28 comme cela a été explicité précédemment.The amplifier 47 of the differential unit receives at its negative input a voltage proportional to the total supply current of the line 4, except the component corresponding to the drain current passing through the modulator 14, and on its positive input a voltage proportional to the total current in line 4. Since the resistors R1, R2, R3 and R4 are of the same value, the output voltage V diff of the differential unit 43 is equal to the resistance 45 multiplied by the drain current of the modulator 14 which is in the a programming step. This voltage is amplified by the amplifier 44 and is then compared with the data voltage U c in the comparison block 28 as explained above.

Selon une variante de réalisation de l'invention, le dispositif d'affichage d'image est un circuit de commande en tension des modulateurs. Le générateur de courant continue 30 est alors remplacé par un générateur d'alimentation en tension et préférentiellement par un générateur de tension en rampe.According to an alternative embodiment of the invention, the image display device is a voltage control circuit of the modulators. The DC generator 30 is then replaced by a voltage supply generator and preferably by a ramp voltage generator.

Dans ce cas, tout comme dans le cas d'un circuit de commande en courant des modulateurs tel décrit précédemment, l'amplitude de la tension de rampe est modulée en fonction de la valeur de l'amplitude de la consigne de données, émise par le pilote de commande 22 de colonne. La durée de la tension de rampe adressée aux circuits d'adressage 6 est également modulée en fonction de la tension de seuil de déclenchement Vth, par les moyens de comparaison 28 et l'unité de contrôle 34.In this case, just as in the case of a current control circuit of the modulators as described above, the amplitude of the ramp voltage is modulated according to the value of the amplitude of the data setpoint, transmitted by the column control driver 22. The duration of the ramp voltage addressed to the addressing circuits 6 is also modulated according to the trigger threshold voltage V th , by the comparison means 28 and the control unit 34.

Les quatre graphes des figures 3A à 3D représentent les étapes d'adressage d'un émetteur lorsque celui-ci est réalisé par le dispositif d'affichage selon l'invention.The four graphs of Figures 3A to 3D represent the addressing steps of an emitter when this is carried out by the display device according to the invention.

Ces étapes comprennent une étape A d'initialisation d'un circuit d'adressage 6, une étape B intermédiaire, une étape C de programmation de celui-ci et une étape D d'émission de lumière proportionnelle au courant de pilotage Idata précédemment programmé.These steps comprise a step A of initialization of an addressing circuit 6, an intermediate step B, a programming step C thereof and a light emission step D proportional to the previously programmed control current I data. .

Au cours de l'étape A d'initialisation, le pilote 20 de commande de ligne applique une tension Vselect à l'électrode 8 de la ligne sélectionnée. Cette tension est appliquée à la grille des interrupteurs 16, reliée à l'électrode de ligne 8. Parallèlement, l'unité de contrôle 34 du contrôleur externe 24 d'une colonne, commande la fermeture de l'interrupteur 40 et une tension Vinit générée par le générateur 38, est appliquée à l'électrode d'adressage 10 de cette colonne. La tension Vinit est appliquée à une borne de la capacité de stockage 18 pour la décharger, l'interrupteur 16 étant fermé.During initialization step A, the line driver 20 applies a select voltage V to the electrode 8 of the selected line. This voltage is applied to the gate of the switches 16, connected to the line electrode 8. In parallel, the control unit 34 of the external controller 24 of a column, controls the closing of the switch 40 and a voltage V init generated by the generator 38, is applied to the addressing electrode 10 of this column. The voltage V init is applied to a terminal of the storage capacitor 18 to discharge it, the switch 16 being closed.

L'étape intermédiaire B est de courte durée et a pour unique fonction de créer un temps mort pour séparer les étapes d'initialisation et de programmation afin d'éviter les courts-circuit.Intermediate step B is short-lived and its sole function is to create a dead time to separate the initialization and programming steps in order to avoid short circuits.

Au cours d'une étape C de programmation, le pilote 22 de commande de colonne émet une tension de données Uc, l'unité de contrôle 34 commande la fermeture de l'interrupteur 32 et le générateur 30 de pilotage génère un courant de pilotage Idata. Comme l'interrupteur 16 est fermé, le courant Idata génère une différence de potentiel entre la grille et la source du modulateur 14.During a programming step C, the column control driver 22 emits a data voltage U c , the control unit 34 controls the closing of the switch 32 and the control generator 30 generates a control current I data . Since the switch 16 is closed, the current I data generates a potential difference between the gate and the source of the modulator 14.

Lorsque cette différence de potentiel est supérieure à la tension de seuil de déclenchement Vth du modulateur 14, un courant de drain Id s'établit entre le drain et la source du modulateur.When this potential difference is greater than the trigger threshold voltage V th of the modulator 14, a drain current I d is established between the drain and the source of the modulator.

L'intensité de ce courant de drain Id qui correspond à une partie du courant circulant dans la ligne 4, est mesurée par l'unité de mesure 26 et une tension représentative de ce courant de drain est comparée à la tension de données Uc adressée par le pilote 22. En variante, lorsque la consigne de données est un courant, l'amplitude de l'intensité de ce courant est comparée à l'intensité du courant de drain.The intensity of this drain current I d, which corresponds to a part of the current flowing in line 4, is measured by the measurement unit 26 and a voltage representative of this drain current is compared with the data voltage U c 22. In a variant, when the data setpoint is a current, the amplitude of the intensity of this current is compared with the intensity of the drain current.

Le courant de drain généré traverse l'émetteur 2 qui s'illumine. Le générateur Vdd alimente en puissance l'émetteur 2.The drain current generated passes through the emitter 2 which lights up. The generator V dd powers the transmitter 2.

L'unité de comparaison 28 compare la tension de données Uc à la tension représentative de l'amplitude du courant de drain Id. Comme visible sur la figure 3D, l'amplitude du courant de drain augmente quadratique en fonction de la tension entre la grille et la source du modulateur. Petit à petit, le courant de pilotage Idata généré par le générateur 30 provoque une accumulation de charges dans la capacité de stockage 18 reliée à la grille du modulateur 14. Cette accumulation de charges provoque l'augmentation de tension Vgs entre la grille et la source du modulateur 14 et en conséquence, l'augmentation progressive du courant de drain Id.The comparison unit 28 compares the data voltage U c with the voltage representative of the amplitude of the drain current I d . As visible on the 3D figure , the amplitude of the drain current increases quadratic depending on the voltage between the gate and the source of the modulator. Little by little, the driving current I data generated by the generator 30 causes an accumulation of charges in the storage capacitor 18 connected to the gate of the modulator 14. This accumulation of charges causes increased voltage V gs between the gate and the source of the modulator 14 and consequently, the progressive increase of the drain current I d .

Lorsque la tension représentative du courant de drain Id est proportionnel à la tension de données Uc. plus exactement lorsque Id = I data k

Figure imgb0001
avec k > 1, l'unité de comparaison 28 envoie un signal d'avertissement S à l'unité de contrôle 34 qui en retour, commande la fermeture de l'interrupteur 32. L'étape de programmation est terminée.When the voltage representative of the drain current I d is proportional to the data voltage U c . more exactly when id = I data k
Figure imgb0001
 with k> 1, the comparison unit 28 sends a warning signal S to the control unit 34 which in turn commands the closing of the switch 32. The programming step is completed.

La durée de l'étape de programmation est variable et dépend du seuil de déclenchement de chaque modulateur de courant de la colonne. Le signal d'adressage de chaque émetteur est donc modulé en durée en fonction des tensions de seuil de déclenchement.The duration of the programming step is variable and depends on the tripping threshold of each current modulator of the column. The addressing signal of each transmitter is therefore modulated in duration as a function of the trigger threshold voltages.

En pratique, le courant Idata est de l'ordre de quelques micro-ampères de sorte que la capacité de stockage 18 et les capacités parasites générées par la structure du panneau de visualisation, sont rapidement chargées. Comme le courant Idata est environ 4 fois supérieur au courant de drain Id, le temps de programmation est court, environ de l'ordre de quelques micros secondes (µs).In practice, the current I data is of the order of a few micro-amps so that the storage capacity 18 and the parasitic capacitances generated by the structure of the display panel are quickly loaded. Since the current I data is approximately 4 times greater than the drain current I d , the programming time is short, approximately of the order of a few micros seconds (μs).

Au cours de l'étape C de programmation, la capacité de stockage 18 a été suffisamment chargée pour que l'émetteur 2 continue d'émettre après son adressage pendant la durée de la trame d'image, en étant toujours alimenté depuis le générateur Vdd.During the programming step C, the storage capacity 18 has been sufficiently charged so that the transmitter 2 continues to transmit after its addressing during the duration of the image frame, always being powered from the generator V dd .

La durée d'adressage du courant de pilotage Idata correspondant à la durée de fermeture de l'interrupteur 32, est à la fois fonction de la tension de seuil de déclenchement Vth du modulateur 14 sélectionné et de la valeur de la consigne Idata. Ainsi, les moyens de compensation 12 du seuil de déclenchement sont aptes à moduler la durée du signal de pilotage Idata à tour de rôle pour chaque modulateur de la colonne d'émetteurs.The duration of addressing of the driving current I data corresponding to the duration of closing of the switch 32 is both a function of the triggering threshold voltage V th of the modulator 14 selected and the value of the setpoint I data. . Thus, the compensation means 12 of the tripping threshold are able to modulate the duration of the control signal I data in turn for each modulator of the transmitter column.

L'étape D débute à la fin de l'étape de programmation et s'achève à la fin de la sélection de la ligne 8. Pendant cette étape D, l'émetteur 2 est toujours sélectionné mais sa programmation est terminée ; il continue d'émettre en fonction de cette programmation grâce à la tension stockée aux bornes de la capacité 28. Pendant le reste de la trame d'image et avant une autre programmation correspondant à une nouvelle trame, le courant de drain Id continue à traverser le modulateur 14 et l'émetteur 2 jusqu'à ce que la tension aux bornes de la capacité de stockage 18 soit déchargée au cours d'une nouvelle étape A d'initialisation de ce circuit d'adressage.Step D begins at the end of the programming step and ends at the end of the selection of the line 8. During this step D, the transmitter 2 is still selected but its programming is complete; it continues to transmit according to this programming thanks to the voltage stored at the terminals of the capacitor 28. During the remainder of the image frame and before another programming corresponding to a new frame, the drain current I d continues to through the modulator 14 and the transmitter 2 until the voltage across the storage capacity 18 is discharged during a new step A initialization of this addressing circuit.

Dès la fin de l'étape C de programmation d'un circuit d'adressage 6 associé à un premier émetteur 2, les pilotes de commande 20, 22 et les moyens de compensation 12 sont utilisés pour la programmation d'un autre circuit d'adressage associé à un second émetteur de la même colonne. Pendant l'étape d'initialisation A du circuit d'adressage associé au second émetteur, le premier émetteur 2 continue à émettre. Le générateur Vdd qui a alimenté en puissance l'émetteur 2 durant l'étape de programmation C continue à l'alimenter tant que la tension de grille du modulateur 14 est supérieure à sa tension de seuil de déclenchement.As soon as the programming step C of an addressing circuit 6 associated with a first transmitter 2 has been completed, the control pilots 20, 22 and the compensation means 12 are used to program another circuit. addressing associated with a second transmitter of the same column. During the initialization step A of the addressing circuit associated with the second transmitter, the first transmitter 2 continues to transmit. The generator V dd which supplied power to the transmitter 2 during the programming step C continues to supply it as long as the gate voltage of the modulator 14 is greater than its trigger threshold voltage.

La figure 4 représente une variante de réalisation de l'invention dans laquelle les moyens de commande 3 sont identiques à ceux représentés sur la figure 1. Cependant, le circuit d'adressage 6 pilotant un émetteur de lumière 2 à structure classique est remplacé par un circuit d'adressage 66 pilotant une émetteur de lumière à structure dite inversée.The figure 4 represents an alternative embodiment of the invention in which the control means 3 are identical to those shown in FIG. figure 1 . However, the addressing circuit 6 driving a light emitter 2 of conventional structure is replaced by an addressing circuit 66 driving a so-called inverted structure light emitter.

Dans ce type de circuit, la cathode des émetteurs 52 forme l'interface avec la matrice active et l'anode des émetteurs 52 est connectée au générateur d'alimentation en puissance Vdd. La source du modulateur 54 est connectée à une masse ou à un générateur de tension négative. La cathode de l'émetteur 52 est raccordée au drain du modulateur 54. La capacité de stockage 58 est branchée entre la grille et la source du modulateur 54. Un interrupteur 56 est adressé en courant Idata par une électrode d'adressage 60 et est sélectionné par une électrode de sélection 68.In this type of circuit, the cathode of the emitters 52 forms the interface with the active matrix and the anode of the emitters 52 is connected to the power supply generator V dd . The source of the modulator 54 is connected to a ground or a negative voltage generator. The cathode of the transmitter 52 is connected to the drain of the modulator 54. The storage capacitor 58 is connected between the gate and the source of the modulator 54. A switch 56 is addressed in current I data by an addressing electrode 60 and is selected by a selection electrode 68.

Le générateur d'alimentation en puissance Vdd est directement raccordé à tous les émetteurs 52 de toutes les colonnes sans interposition d'une unité de commutation. En conséquence, ce générateur Vdd alimente en puissance tous les émetteurs 52 pendant l'étape C de programmation et pendant l'étape D tout au long de la durée de la trame d'image. En conséquence, ce sont les moyens d'alimentation en puissance Vss qui sont connectés séparément au moyen de compensation 12.The power supply generator V dd is directly connected to all emitters 52 of all the columns without the interposition of a switching unit. As a result, this generator V dd powers all the emitters 52 during the programming step C and during the step D throughout the duration of the image frame. Consequently, it is the power supply means V ss which are connected separately to the compensation means 12.

Comme les moyens d'alimentation sont directement connectés à chaque modulateur ou directement connectés à chaque émetteur d'une colonne, le schéma électrique du dispositif d'affichage est simplifié et techniquement plus facilement réalisable.Since the supply means are directly connected to each modulator or directly connected to each emitter of a column, the electrical diagram of the display device is simplified and technically more easily achievable.

Comme chaque générateur d'alimentation en puissance Vss est apte à alimenter l'ensemble des émetteurs 52 d'une colonne et que chaque électrode d'adressage 60 est également apte à adresser l'ensemble des émetteurs 52 d'une colonne, les moyens de compensation 12 sont aptes à compenser successivement la tension de seuil de déclenchement Vth de l'ensemble des modulateurs 14 d'une colonne.Since each power supply generator V ss is capable of supplying all the emitters 52 of a column and each addressing electrode 60 is also able to address all the emitters 52 of a column, the means compensation 12 are able to successively compensate the trigger threshold voltage V th of all the modulators 14 of a column.

Par ailleurs, comme les moyens de compensation 12 déterminent la durée du signal avant chaque trame, les variations du seuil de déclenchement liées au vieillissement des modulateurs sont automatiquement compensées.Moreover, since the compensation means 12 determine the duration of the signal before each frame, the variations of the tripping threshold related to the aging of the modulators are automatically compensated.

Avantageusement, aucune unité de commutation n'est interposée entre le générateur Vdd ou Vss et le modulateur 14 ou l'émetteur 52 pour commuter entre deux sources d'alimentation de l'émetteur au cours du processus de programmation et d'émission de celui-ci. En conséquence, la surface utile d'émission de lumière des pixels est augmentée.Advantageously, no switching unit is interposed between the generator V dd or V ss and the modulator 14 or the transmitter 52 to switch between two power supply sources of the transmitter during the programming and transmission process. this one. As a result, the useful light emitting area of the pixels is increased.

Comme le circuit d'adressage est adressé par un courant ou une tension analogique et non numérique, les moyens de contrôle sont simplifiés et leur implémentation est facilitée.As the addressing circuit is addressed by a current or an analog and non-digital voltage, the control means are simplified and their implementation is facilitated.

Avantageusement, les moyens de compensation de l'ensemble des colonnes compensent les dispersions des tensions de seuil de déclenchement des modulateurs de circuits de commande d'un écran à matrice active.Advantageously, the compensation means of all the columns compensate for the dispersions of the trigger threshold voltages of the control circuit modulators of an active matrix screen.

Avantageusement, l'unité 26 de mesure du courant traversant un modulateur pendant une étape de programmation C, permet de se dispenser d'une unité de commutation associée à chaque émetteur.Advantageously, the unit 26 for measuring the current passing through a modulator during a programming step C, makes it possible to dispense with a switching unit associated with each transmitter.

Avantageusement, comme l'intensité du courant de pilotage Idata est élevée, les capacités parasites générées par la colonne d'adressage du panneau de visualisation sont rapidement chargées. En conséquence, le dispositif d'affichage est adressé instantanément.Advantageously, since the intensity of the driving current I data is high, the parasitic capacitances generated by the addressing column of the display panel are quickly loaded. As a result, the display device is addressed instantly.

Claims (13)

  1. An active-matrix image display device comprising:
    - several light emitters (2; 52) forming an array of emitters distributed in rows and columns;
    - power supply means (Vdd) capable of supplying current simultaneously to all of the emitters (2; 52) of a column;
    - means (3) for controlling the emission of the emitters (2; 52) comprising:
    - for each emitter (2; 52) of the array, a current modulator (14; 54) comprising a source electrode, a drain electrode and a gate electrode, a drain current (Id) being able to pass through said modulator in order to supply said emitter (2; 52), for a voltage between the drain or the source and the gate equal to or greater than a trip-threshold voltage (Vth),
    - for each column of emitters (2; 52), column address means (10; 60) capable of addressing in succession each emitter (2; 52) of said column of emitters by applying a value (Idata, Vdata) representative of a data setpoint (Uc) to the gate electrode of the modulator (14; 54) associated with this emitter (2; 52), in order to actuate it, during a programming step,
    - for each row of emitters (2; 52), row select means (8; 68) capable of selecting in succession the emitters (2; 52) of each row of emitters, during the programming step and
    - for each modulator (14; 54), storage means (18) capable of storing electric charges at the gate electrode of the modulator (14; 54); and
    - trip-threshold voltage compensation means (12) comprising comparators (28), the comparators (28) being capable of comparing, during the step of programming a selected emitter (2; 52), a value representative of the drain current (Id) supplying the selected emitter with the value (Idata, Vdata) representative of the data setpoint (Uc) for controlling the quantity of charge stored in the storage means (18),
    characterized in that the compensation means (12) comprise, for each column of emitters (2; 52), a single unit (26) for determining a representative value of the drain current (Id) supplying the selected emitter (2; 52) on the basis of a measurement of a representative value of the current for supplying all of the emitters (2; 52) of the column that remain supplied by the same supply means both during programming steps and during emission steps.
  2. The image display device as claimed in claim 1, characterized in that the power supply means (Vdd) for the emitters are connected directly to each modulator (14) of the control means.
  3. The image display device as claimed in claim 1, characterized in that the power supply means (Vdd) for the emitters are connected directly to each emitter (2) of a column.
  4. The image display device as claimed in any one of the preceding claims,
    characterized in that the power supply means (Vdd) for the emitters comprise a voltage supply generator capable of supplying all of the emitters of a column and in that the compensation means (12) are capable of compensating in succession the trip-threshold voltage (Vth) of each modulator (14; 54) of all of the emitters of a column.
  5. The image display device as claimed in any one of the preceding claims,
    characterized in that the compensation means (12) further include:
    - a drive generator (30) capable of generating a drive signal (Idata) applied to the gate of said modulator (14; 54); and
    - means (28, 34) for modulating the duration of said drive signal (Idata) according to the value of the data setpoint (Uc) and the value of the trip-threshold voltage (Vth).
  6. The image display device as claimed in any one of the preceding claims,
    characterized in that the data setpoint (Uc) is a data voltage and in that the comparators (28) are capable of emitting a warning signal (S) when the voltage representative of the intensity of the drain current (Id) is equal to a number of times said data voltage.
  7. The image display device as claimed in claim 5 in combination with claim 6,
    characterized in that the means for modulating the duration of the drive signal (Idata) comprise:
    - a switch (32) connected in series with the drive generator (30); and
    - a control unit (34) capable of switching said switch (32), on the one hand, when the data setpoint (Uc) is received, and on the other hand, when the warning signal (S) is received.
  8. The image display device as claimed in any one of claims 5 to 7, characterized in that the drive signal (Idata) generated by the drive generator (30) is amplitude-modulated according to the value of the data setpoint (Uc).
  9. The image display device as claimed in any one of claims 5 to 8, characterized in that the drive generator (30) is a current generator and the modulator (14; 54) is capable of being current-controlled.
  10. The image display device as claimed in any one of claims 5 to 8, characterized in that the drive generator (30) is a ramp voltage generator and the modulator (14; 54) is capable of being voltage-controlled.
  11. The image display device as claimed in any one of the preceding claims,
    characterized in that the compensation means (12) further include a unit (26) for measuring the intensity of a current, capable of measuring the intensity of the drain current (Id) passing through a selected emitter (2) during the programming step (C).
  12. The image display device as claimed in claim 11, characterized in that the supply means comprise a line (4) to which the measurement unit (26) is directly connected.
  13. The image display device as claimed in any one of the preceding claims,
    characterized in that the storage means comprise at least one storage capacitor (18) connected to the gate and to the source of the modulator (14) and in that the compensation means (12) further include reset means (36) capable of applying a voltage pulse to said capacitor in order to discharge it.
EP04816458A 2003-12-23 2004-12-21 Device for displaying images on an oled active matrix Not-in-force EP1697920B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR0315295 2003-12-23
PCT/FR2004/003328 WO2005071649A1 (en) 2003-12-23 2004-12-21 Device for displaying images on an active matrix

Publications (2)

Publication Number Publication Date
EP1697920A1 EP1697920A1 (en) 2006-09-06
EP1697920B1 true EP1697920B1 (en) 2009-10-14

Family

ID=34803296

Family Applications (1)

Application Number Title Priority Date Filing Date
EP04816458A Not-in-force EP1697920B1 (en) 2003-12-23 2004-12-21 Device for displaying images on an oled active matrix

Country Status (9)

Country Link
US (1) US8610651B2 (en)
EP (1) EP1697920B1 (en)
JP (1) JP2007515688A (en)
KR (1) KR20060123355A (en)
CN (1) CN1898719B (en)
AT (1) ATE445895T1 (en)
DE (1) DE602004023649D1 (en)
MX (1) MXPA06007060A (en)
WO (1) WO2005071649A1 (en)

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1863005B1 (en) * 2006-06-01 2010-08-04 Thomson Licensing Video display device and operating method therefore
EP1863001A1 (en) * 2006-06-01 2007-12-05 Thomson Licensing Video display device and operating method therefore
JP5240538B2 (en) * 2006-11-15 2013-07-17 カシオ計算機株式会社 Display driving device and driving method thereof, and display device and driving method thereof
US8026873B2 (en) * 2007-12-21 2011-09-27 Global Oled Technology Llc Electroluminescent display compensated analog transistor drive signal
JP5107824B2 (en) * 2008-08-18 2012-12-26 富士フイルム株式会社 Display device and drive control method thereof
US8194063B2 (en) * 2009-03-04 2012-06-05 Global Oled Technology Llc Electroluminescent display compensated drive signal
CN102364568B (en) * 2011-06-27 2013-11-06 昆山工研院新型平板显示技术中心有限公司 Pixel cell circuit of AMOLED (active matrix/organic light emitting diode) and organic light-emitting display device
US10847979B2 (en) * 2018-12-14 2020-11-24 Zhuhai Jieli Technology Co., Ltd Charging and communication system

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP3308880B2 (en) * 1997-11-07 2002-07-29 キヤノン株式会社 Liquid crystal display and projection type liquid crystal display
JP2001147659A (en) * 1999-11-18 2001-05-29 Sony Corp Display device
JP3688564B2 (en) * 2000-07-24 2005-08-31 株式会社神戸製鋼所 Chemical bomb demolition equipment
JP2002091377A (en) 2000-09-11 2002-03-27 Hitachi Ltd Organic el display device
TW561445B (en) * 2001-01-02 2003-11-11 Chi Mei Optoelectronics Corp OLED active driving system with current feedback
KR100370095B1 (en) * 2001-01-05 2003-02-05 엘지전자 주식회사 Drive Circuit of Active Matrix Formula for Display Device
JP2002278513A (en) * 2001-03-19 2002-09-27 Sharp Corp Electro-optical device
US7224333B2 (en) * 2002-01-18 2007-05-29 Semiconductor Energy Laboratory Co. Ltd. Display device and driving method thereof

Also Published As

Publication number Publication date
MXPA06007060A (en) 2006-09-04
KR20060123355A (en) 2006-12-01
US8610651B2 (en) 2013-12-17
EP1697920A1 (en) 2006-09-06
ATE445895T1 (en) 2009-10-15
CN1898719B (en) 2010-04-21
CN1898719A (en) 2007-01-17
DE602004023649D1 (en) 2009-11-26
US20080272993A1 (en) 2008-11-06
JP2007515688A (en) 2007-06-14
WO2005071649A1 (en) 2005-08-04

Similar Documents

Publication Publication Date Title
EP1644913B1 (en) Display device and control circuit for a light modulator
EP2013863A1 (en) Organic electroluminescent display
FR2884639A1 (en) ACTIVE MATRIX IMAGE DISPLAY PANEL, THE TRANSMITTERS OF WHICH ARE POWERED BY POWER-DRIVEN POWER CURRENT GENERATORS
EP0972282B1 (en) Device for controlling a matrix display cell
FR2864678A1 (en) ELECTROLUMINESCENCE DISPLAY DEVICE AND METHOD OF CONTROLLING THE SAME
FR2882457A1 (en) PIXEL ADDRESSING CIRCUIT AND METHOD FOR CONTROLLING SUCH CIRCUIT
EP1697920B1 (en) Device for displaying images on an oled active matrix
EP1667100A1 (en) Automatic adaptation of the precharge voltage for an electroluminescent screen
WO2005059883A2 (en) Electronic control cell for an active matrix display organic electroluminescent diode and methods for the operation thereof and display
EP1964095B1 (en) Display panel and control method using transient capacitive coupling
EP1964094B1 (en) Method for controlling a display panel by capacitive coupling
EP1700290B1 (en) Image display screen and method of addressing said screen
EP1771838B1 (en) Image display device and display device control method
EP1864275B1 (en) Image display device and method of controlling same
EP1697919B1 (en) Image display screen
FR2832537A1 (en) METHOD AND DEVICE FOR VOLTAGE CONTROL OF A MATRIX STRUCTURED ELECTRON SOURCE WITH REGULATION OF THE CHARGE EMITTED
EP0513325A1 (en) Width pulse generator having a temporal vernier
FR2886497A1 (en) ACTIVE MATRIX VIDEO IMAGE DISPLAY DEVICE WITH CORRECTION OF NON-UNIFORMITY LUMINANCE
EP1697997A1 (en) Image display screen and method for controlling said screen
FR2843225A1 (en) Active matrix image display device with compensation for trigger thresholds, uses measurement of current drawn by pixel driver to determine its threshold voltage and generates correction to command voltage to match threshold voltage

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 20060620

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LI LT LU MC NL PL PT RO SE SI SK TR

DAX Request for extension of the european patent (deleted)
RTI1 Title (correction)

Free format text: DEVICE FOR DISPLAYING IMAGES ON AN OLED ACTIVE MATRIX

GRAP Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOSNIGR1

GRAS Grant fee paid

Free format text: ORIGINAL CODE: EPIDOSNIGR3

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LI LT LU MC NL PL PT RO SE SI SK TR

REG Reference to a national code

Ref country code: GB

Ref legal event code: FG4D

Free format text: NOT ENGLISH

REG Reference to a national code

Ref country code: CH

Ref legal event code: EP

REG Reference to a national code

Ref country code: IE

Ref legal event code: FG4D

REF Corresponds to:

Ref document number: 602004023649

Country of ref document: DE

Date of ref document: 20091126

Kind code of ref document: P

RAP2 Party data changed (patent owner data changed or rights of a patent transferred)

Owner name: THOMSON LICENSING

LTIE Lt: invalidation of european patent or patent extension

Effective date: 20091014

NLV1 Nl: lapsed or annulled due to failure to fulfill the requirements of art. 29p and 29m of the patents act
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20091014

Ref country code: PT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20100215

Ref country code: IS

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20100214

Ref country code: FI

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20091014

Ref country code: SE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20091014

Ref country code: ES

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20100125

REG Reference to a national code

Ref country code: IE

Ref legal event code: FD4D

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: PL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20091014

Ref country code: SI

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20091014

BERE Be: lapsed

Owner name: THOMSON LICENSING

Effective date: 20091231

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: AT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20091014

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: MC

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20100701

Ref country code: IE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20091014

Ref country code: BG

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20100114

Ref country code: RO

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20091014

Ref country code: DK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20091014

Ref country code: EE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20091014

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: CZ

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20091014

Ref country code: SK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20091014

26N No opposition filed

Effective date: 20100715

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LI

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20091231

Ref country code: GR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20100115

Ref country code: BE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20091231

Ref country code: CH

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20091231

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20091014

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 20101231

Year of fee payment: 7

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LU

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20091221

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: HU

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20100415

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: TR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20091014

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: CY

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20091014

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 20111221

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: NL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20091014

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20111221

REG Reference to a national code

Ref country code: FR

Ref legal event code: PLFP

Year of fee payment: 12

REG Reference to a national code

Ref country code: FR

Ref legal event code: PLFP

Year of fee payment: 13

REG Reference to a national code

Ref country code: FR

Ref legal event code: PLFP

Year of fee payment: 14

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 20201209

Year of fee payment: 17

Ref country code: FR

Payment date: 20201228

Year of fee payment: 17

REG Reference to a national code

Ref country code: DE

Ref legal event code: R119

Ref document number: 602004023649

Country of ref document: DE

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20220701

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20211231

P01 Opt-out of the competence of the unified patent court (upc) registered

Effective date: 20230527