WO2004047064A1 - 有機elディスプレイ及びアクティブマトリクス基板 - Google Patents
有機elディスプレイ及びアクティブマトリクス基板 Download PDFInfo
- Publication number
- WO2004047064A1 WO2004047064A1 PCT/JP2003/014705 JP0314705W WO2004047064A1 WO 2004047064 A1 WO2004047064 A1 WO 2004047064A1 JP 0314705 W JP0314705 W JP 0314705W WO 2004047064 A1 WO2004047064 A1 WO 2004047064A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- terminal
- switch
- control
- video signal
- control terminal
- Prior art date
Links
- 239000011159 matrix material Substances 0.000 title claims abstract description 25
- 239000000758 substrate Substances 0.000 title claims description 14
- 239000003990 capacitor Substances 0.000 claims abstract description 21
- 239000010409 thin film Substances 0.000 claims description 19
- 229910021420 polycrystalline silicon Inorganic materials 0.000 claims description 13
- 229920005591 polysilicon Polymers 0.000 claims description 13
- 239000012535 impurity Substances 0.000 claims description 10
- 230000004044 response Effects 0.000 claims description 4
- 229920001621 AMOLED Polymers 0.000 claims 1
- 239000010410 layer Substances 0.000 description 20
- 238000000034 method Methods 0.000 description 15
- 238000010586 diagram Methods 0.000 description 10
- 239000010408 film Substances 0.000 description 7
- 239000004065 semiconductor Substances 0.000 description 4
- 230000003111 delayed effect Effects 0.000 description 3
- 239000002019 doping agent Substances 0.000 description 3
- 239000011229 interlayer Substances 0.000 description 3
- 230000004048 modification Effects 0.000 description 3
- 238000012986 modification Methods 0.000 description 3
- 239000004973 liquid crystal related substance Substances 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 230000000630 rising effect Effects 0.000 description 2
- 230000008859 change Effects 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000005669 field effect Effects 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 239000012044 organic layer Substances 0.000 description 1
- 229920002120 photoresistant polymer Polymers 0.000 description 1
- 238000010791 quenching Methods 0.000 description 1
- 230000000171 quenching effect Effects 0.000 description 1
- 238000002834 transmittance Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
- G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
- G09G3/22—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources
- G09G3/30—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using electroluminescent panels
- G09G3/32—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using electroluminescent panels semiconductive, e.g. using light-emitting diodes [LED]
- G09G3/3208—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using electroluminescent panels semiconductive, e.g. using light-emitting diodes [LED] organic, e.g. using organic light-emitting diodes [OLED]
- 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
- G09G3/3241—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 the current through the light-emitting element being set using a data current provided by the data driver, e.g. by using a two-transistor current mirror
- G09G3/325—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 the current through the light-emitting element being set using a data current provided by the data driver, e.g. by using a two-transistor current mirror the data current flowing through the driving transistor during a setting phase, e.g. by using a switch for connecting the driving transistor to the data driver
-
- 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
- G09F—DISPLAYING; ADVERTISING; SIGNS; LABELS OR NAME-PLATES; SEALS
- G09F9/00—Indicating arrangements for variable information in which the information is built-up on a support by selection or combination of individual elements
- G09F9/30—Indicating arrangements for variable information in which the information is built-up on a support by selection or combination of individual elements in which the desired character or characters are formed by combining individual 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
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B33/00—Electroluminescent light sources
- H05B33/12—Light sources with substantially two-dimensional radiating surfaces
- H05B33/14—Light sources with substantially two-dimensional radiating surfaces characterised by the chemical or physical composition or the arrangement of the electroluminescent material, or by the simultaneous addition of the electroluminescent material in or onto the light source
-
- 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
- G09G2300/0809—Several active elements per pixel in active matrix panels
- G09G2300/0819—Several active elements per pixel in active matrix panels used for counteracting undesired variations, e.g. feedback or autozeroing
-
- 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
- G09G2300/0842—Several active elements per pixel in active matrix panels forming a memory circuit, e.g. a dynamic memory with one capacitor
-
- 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
- G09G2300/0842—Several active elements per pixel in active matrix panels forming a memory circuit, e.g. a dynamic memory with one capacitor
- G09G2300/0861—Several active elements per pixel in active matrix panels forming a memory circuit, e.g. a dynamic memory with one capacitor with additional control of the display period without amending the charge stored in a pixel memory, e.g. by means of additional select electrodes
-
- 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
-
- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G2330/00—Aspects of power supply; Aspects of display protection and defect management
- G09G2330/02—Details of power systems and of start or stop of display operation
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
- H10K59/00—Integrated devices, or assemblies of multiple devices, comprising at least one organic light-emitting element covered by group H10K50/00
- H10K59/10—OLED displays
- H10K59/12—Active-matrix OLED [AMOLED] displays
Definitions
- the present invention relates to an active matrix display and an active matrix substrate, and more particularly, to an active matrix including an organic EL (Electro-Luminescent) element as a display element.
- the present invention relates to a Bumatrix type organic EL display and an active matrix substrate that can be used therein.
- Flat panel displays typified by liquid crystal displays have the characteristics of being thinner, lighter, and have lower power consumption than CRT displays. Due to these characteristics, demand for flat panel displays is growing rapidly.
- each pixel is provided with a switch that can electrically separate an ON pixel from an OFF pixel. Normally, this pixel is further provided with a capacitor for holding a video signal. Therefore, this display can realize good display quality without crosstalk between adjacent pixels. For this reason, the active matrix type flat panel display is being used as a display for various types of electronic devices such as portable information terminals. It has become.
- organic EL displays have been actively developed, and are self-luminous displays, which have higher response speed and wider viewing angle than liquid crystal displays. This is advantageous for realization.
- FIG. 1 is an equivalent circuit diagram of a pixel circuit disclosed by Knapp. The operation of this circuit is performed in two stages. In the first and second stages, the power supply line 31 is set to the potential V 1 and the power supply line 34 is set to the potential V 2 higher than the potential V 1.
- the switch 33 is opened (OFF), and the switches 32 and 37 are closed (ON).
- the signal current is supplied from the video signal wiring 35 to the organic EL element 20 as an input signal. Since the transistor 30 is diode-connected by the switch 32, a voltage equal to the gate-source voltage of the transistor 30 carrying the signal current is stored in the capacitor 38. You. Thereafter, switches 32 and 37 are opened.
- the switch 33 is closed, and the organic EL element 20 and the drain of the transistor 30 are connected. Since a voltage corresponding to the input signal is stored in the capacitor 38, a current substantially equal to the input signal is supplied to the organic EL element 20.
- An object of the present invention is to provide an active matrix type organic EL display capable of realizing excellent display quality with a relatively small number of wires and an active matrix substrate usable for the same. It is in.
- a first terminal connected to a first power supply terminal, a control terminal to which a video signal is supplied from a video signal input terminal, and a voltage between the control terminal and the first terminal
- a drive control element including a second terminal that outputs a drive current having a size corresponding to the following; an organic EL element connected between the second terminal and the second power supply terminal;
- a capacitor connected to the control terminal and capable of maintaining a voltage between the control terminal and the first terminal at a magnitude corresponding to the video signal; and a video signal input during a signal writing period according to a scanning signal.
- Switch and scanning The control terminal and the second terminal are connected to each other during the signal writing period, and the control terminal and the second terminal are connected before the first switch is disconnected.
- an active matrix type organic EL display including: a second switch that switches between two terminals and a non-connected state.
- a first terminal connected to the first power supply terminal, a control terminal, and a drive current having a magnitude corresponding to a voltage between the control terminal and the first terminal are output.
- a drive control element having a second terminal; an organic EL element connected between the second terminal and the second power supply terminal; a capacitor connected between a constant potential terminal and the control terminal;
- a first switch connected between the video signal input terminal and the second terminal;
- a second switch connected between the first switch and the second terminal, and a control terminal for controlling the switching of the first switch is a control terminal for controlling the switching of the second switch.
- An active matrix organic EL display is provided, wherein the threshold of the first switch is shallower than the threshold of the second switch.
- a first terminal connected to a first power supply terminal, a control terminal, and a drive current having a magnitude corresponding to a voltage between the control terminal and the first terminal are output.
- a drive control element having a second terminal; an organic EL element connected between the second terminal and the second power supply terminal; a capacitor connected between a constant potential terminal and the control terminal;
- a delay element having an input terminal connected to the control signal input terminal, and an output terminal for outputting a control signal supplied from the control signal input terminal; and a delay element between the video signal.
- the terminal is connected to the output terminal and the switch of the second switch is
- a control terminal for controlling the quenching is active Conclusions Li box-type organic E L di splay connected to the control signal input terminal is provided.
- an active matrix substrate on which an organic EL element is to be formed wherein a video signal is supplied from a first terminal connected to a power supply terminal and a video signal input terminal.
- the control terminal is connected to the organic EL element and the control terminal is connected to the control terminal.
- a drive control element comprising: a second terminal that outputs a drive current having a magnitude corresponding to a voltage between the control terminal and the first terminal; and one electrode connected to the control terminal; and A capacitor capable of maintaining a voltage between the first terminal and the voltage corresponding to the video signal; and a video signal input terminal and the second terminal during a signal writing period according to a scanning signal.
- a pixel electrode a first terminal connected to a power supply terminal, a control terminal to which a video signal is supplied from a video signal input terminal, and a connection to the pixel electrode
- a drive control element including: a second terminal that outputs a drive current having a magnitude corresponding to a voltage between the control terminal and the first terminal; one electrode connected to the control terminal; A capacitor capable of maintaining a voltage between the terminal and the first terminal at a magnitude corresponding to the video signal; and a video signal input terminal and the second terminal during a signal writing period according to a scanning signal. And are connected, and the video signal input terminal and the second terminal are disconnected from each other in a light emitting period following the signal writing period.
- a first switch for switching, and the control terminal and the second terminal are connected to each other during the signal writing period according to the scan signal, and the first switch is connected to the first switch.
- An active matrix substrate including a second switch for switching the control terminal and the second terminal to a disconnected state before the switch is disconnected. Provided.
- Figure 1 is an equivalent circuit diagram of a conventional pixel circuit
- FIG. 2 is a plan view schematically showing an organic EL display according to the first embodiment of the present invention
- FIG. 3 is a plan view schematically showing an example of a structure that can be adopted for the pixel of the organic EL display shown in FIG. 2;
- FIG. 4 is a timing chart showing an example of a driving method of the organic EL display of FIG. 1;
- FIG. 5 is a plan view schematically showing a modified example of the pixel structure of FIG. 3;
- FIG. 7 is a cross-sectional view schematically showing an example of a structure that can be adopted for the first switch
- FIG. 8 is a plan view schematically showing an organic EL display according to the second embodiment of the present invention.
- Figure 9 is a diagram showing an example of the waveform of the signal input to the delay element and the signal output by the delay element;
- Figure 10 shows the pixels that can be used for the OLED display in Figure 8.
- FIG. 11 is an equivalent circuit diagram showing another example of a pixel circuit that can be employed in the organic EL display of FIG. 8;
- FIG. 12 is an equivalent circuit diagram showing still another example of a pixel circuit that can be used in the organic EL display of FIG.
- FIG. 2 is a plan view schematically showing the organic EL display according to the first embodiment of the present invention.
- FIG. 3 is a plan view schematically showing an example of a structure that can be employed in the pixel of the organic EL display shown in FIG.
- the organic EL display 1 includes an insulating substrate 10 made of, for example, glass. A plurality of pixels arranged in a matrix and a drive circuit for driving these pixels are arranged on the substrate 10.
- the driving circuit was connected to a video signal line driver 11, a scanning signal line driver 12, a video signal line 35 connected to the video signal line driver 11, and a scan signal line driver 12. It includes a control line 36 as a scanning signal line, a first power supply line 31, and a second power supply line 34.
- This drive circuit drives each pixel circuit based on externally supplied control signals YST, YCLK, XST and XCLK, power supply potentials V dd and V ss, and a data signal I in.
- Each pixel includes a display element 20 and a pixel circuit for driving the display element 20.
- the pixel circuit and the display element 20 are connected in series between a first power supply terminal set to the potential V dd and a second power supply terminal set to the potential V ss.
- the first and second power supply terminals are connected to a first power supply line 31 and a second power supply line 34, respectively.
- the potential V dd is the potential
- the display element 20 includes a pair of electrodes facing each other and an active layer (activlayer) interposed therebetween.
- the “active layer” here is a layer whose optical characteristics such as luminance and transmittance change according to the voltage applied between the electrodes.
- the display element 20 is an organic EL element, and has an organic layer including an organic light emitting layer as an active layer.
- the pixel circuit includes a drive control element 30, a capacitor 38, a first switch 37, a second switch 32, and a third switch 33.
- As the drive control element 30 and the switches 37, 32, and 33 for example, field effect transistors of the first conductivity type can be used. In this example, a p-channel thin-film transistor is used as the drive control element 30 and the switches 37, 32, and 33.
- the first terminal of the drive control element 30, that is, the source, is a potential
- the capacitor 38 has one electrode connected to the control terminal of the drive control element 30, that is, the gate, and the potential difference between the first terminal and the control terminal of the drive control element 30 corresponding to the video signal. Keep. here.
- the capacitor 38 is connected between the first power supply terminal and the control terminal of the drive control element 30.
- the first switch 37 is connected between the video signal input terminal and the second terminal of the drive control element 30, that is, the drain. Note that the video signal input terminal is connected to the video signal line 35.
- the second switch 32 is connected between the gate of the drive control element 30 and the drain.
- the control terminals of the first switch 37 and the second switch 32, that is, the gates, are connected to a control line 36 which is a scanning signal line.
- the third switch 33 is connected between the drain of the drive control element 30 and the first electrode 21 of the display element 20.
- the first electrode 21 is an anode
- the second electrode of the display element 20 is a cathode connected to a second power supply terminal set to the potential Vss.
- the first power supply terminal is used as a constant potential terminal to which the capacitor 38 is to be connected.
- the capacitor 38 is connected to another constant potential terminal and the control terminal of the drive control element 30. It may be connected between.
- the input terminal of the switch 37 included in each pixel column, that is, the source, is connected to one common video signal line 35 for each column.
- the video signal line 35 is supplied with a signal current from the video signal line driver 11 as an input signal or a video signal I in.
- the control terminals of the switches 37 and 32 included in each pixel row, that is, the gates, are commonly connected to one scanning signal line 36 for each row.
- a voltage signal is sequentially supplied to the scanning signal line 36 as a scanning signal S can from the scanning signal line driver 12. Is done.
- the organic EL display 1 excluding at least one electrode and the active layer of the display element 20 corresponds to an active matrix substrate.
- the active matrix substrate includes an insulating substrate 10, wiring such as a video signal line 35, a scanning signal line 36, and a power supply line, and a pixel circuit.
- the active matrix substrate may optionally include the video signal line driver 11, the scanning signal line driver 12, and the first electrode 21 of the display element 20.
- the first switch 37 and the second switch 32 can have the same laminated structure and can be formed simultaneously.
- the first switch 37 and the second switch 32 are thin film transistors having a top gate structure using polysilicon for a semiconductor layer and formed at the same time.
- the first switch 37 and the second switch 32 are different from each other in that the channel length L1 of the first switch 37 is greater than the channel length L2 of the second switch 32.
- the design is made to have the same structure as each other, except that the length is set shorter. As a result, a first switch 37 having a shallower threshold Vthl and a second switch 32 having a deeper threshold Vth2 are obtained.
- the first switch 37 and the second switch 32 a thin film transistor having a top gate structure (cobraner type) using polysilicon for a semiconductor layer is used.
- the first switch 37 and the second switch 32 have the same laminated structure, and They form simultaneously.
- the channel width of each of the first switch 37 and the second switch 32 is 3 wrn
- the channel width of the first switch 37 and the second switch 32 is The length is, for example, 3 / m and 4.5 m, respectively.
- each pixel circuit the gates of the first switch 37 and the second switch 32 are connected to the same scanning signal line 36. Therefore, the same control signal is simultaneously supplied to the gates of the first switch 37 and the second switch 32.
- the second switch 32 having a deeper threshold V th2 has a lower depth.
- the OFF operation is started. That is, in the organic EL display 1, the second switch 32 can be turned off before the first switch 37 is turned off.
- the OFF operation of the second switch 32 precedes the OFF operation of the first switch 37, and, as a result, the gate-source voltage of the drive control element 30. Can be prevented from fluctuating. Therefore, it is possible to suppress the occurrence of gradation collapse and in-plane non-uniformity of luminance, and it is possible to realize excellent display quality with a relatively small number of wirings.
- the channel lengths of the first switch 32 and the second switch 37 are the same as those of other transistors, capacitors, and wiring included in the pixel circuit. It can be set appropriately as long as it does not hinder any arrangement.
- the third switch 33 and the drive control element 30 can be designed to have substantially the same structure as the first switch 32 and the second switch 37.
- a thin film transistor of the first conductivity type may be used as the first to third switches 32, 37 and 33 in parallel with the drive control element 30, and these may be formed simultaneously.
- a pixel circuit can be formed in relatively few steps.
- FIG. 4 is a timing chart showing an example of a driving method of the organic EL display of FIG.
- the scanning signal line driver 12 sequentially outputs, to the scanning signal line 36, a scanning signal Scan that makes the first switch 37 and the second switch 32 conductive.
- the rise and fall of the scan signal S can become gentle due to wiring resistance and capacitance. For example, as shown in FIG. 4, the potential waveform of the scanning signal S chan is dull by the time constant.
- the running signal line driver 12 sequentially outputs a control signal G for making the third switch 33 conductive, to the row of the third switch 33.
- the light emission period is a period in which the third switch 33 is in a conductive state.
- the video signal is written in units of rows, and the period during which writing is performed in a certain row is defined as the light emission period of another row.
- the third switch 3 Reference numeral 3 denotes a non-conductive state, and the display element 30 and the pixel circuit are electrically insulated.
- the scan signal S c an that makes the first switch 37 and the second switch 32 conductive is supplied to the scan signal line 36.
- the first switch 37 having the shallower threshold V thl becomes conductive
- the second switch 32 having the deeper threshold V th2 becomes conductive.
- the input signal I in is supplied from the video signal line driver 11 to the pixel circuit via the video signal line 35. That is, a drive current corresponding to the input signal I in flows through the drive control element.
- the gate potential of drive control element 30 is set to a value corresponding to input signal I in.
- the scan signal Scan supplied from the scan signal line driver 12 to the scan signal line 36 is an ON signal that makes the first switch 37 and the second switch 32 conductive. Changes to an OFF signal that turns them off. Accordingly, first, the second switch 32 having the deeper threshold V th2 is turned off, and then the first switch 37 having the shallower threshold V th1 is turned off. It becomes conductive. Therefore, leakage of charges from the capacitor 38 is prevented, and the gate potential of the drive control element 30 is maintained at a value corresponding to the input signal I in.
- the third switch 33 is turned on by the control signal G supplied thereto. Since the gate potential of the drive control element 30 is maintained at a value corresponding to the input signal Iin, a current substantially equal to the input signal Iin flows through the organic EL element 20. It is. That is, the organic EL element 20 emits light at a luminance corresponding to the input signal I in.
- the channel length L2 of the second switch 32 is set to be longer than the channel length L1 of the first switch 37.
- the threshold value Vth2 of the second switch 32 becomes deeper than the threshold value Vthl of the first switch 37.
- the first switch 37 is turned off before the first switch 37 is turned off.
- the second switch 32 can be turned off. Therefore, according to this embodiment, it is possible to realize the organic EL display 1 in which the gradation collapse and the in-plane unevenness of the brightness are suppressed.
- each of the first switch 37 and the second switch 32 has one channel between the source and the drain, but these switches are different from each other. It may have the following structure.
- the first switch 37 and the second switch 32 may employ a multi-gate structure having a plurality of channels between the source and the drain.
- FIG. 5 is a plan view schematically showing a modification of the pixel structure of FIG.
- the multi-gate structure can be adopted for one or both of the first switch 37 and the second switch 32. However. From the viewpoint of suppressing the influence of the OFF current on the display operation, it is desirable to adopt a multi-gate structure for the second switch 32 as shown in FIG.
- the difference between the threshold values of the first switch 37 and the second switch 32 is about 0.2 V to IV.
- the second switch 32 can be more reliably turned off before the first switch 37 is turned off.
- the thresholds of the first switch 37 and the second switch 32 are made different by using the channel length.However, those thresholds may be made different by other methods. it can. For example, the threshold may be different between the first switch 37 and the second switch 32 using the number of channels. That is, even if the total value of the channel lengths is the same, if the number of channels of the second switch 32 is larger than the number of channels of the first switch 37, the second switch 32 The threshold value is deeper than the threshold value of the first switch 37.
- the dose of the impurity may be different between the first switch 37 and the second switch 32.
- the dose of the p-type dopant to the channel of the first switch 37 will be increased. If the amount is greater than the dose of the p-type dopant to the channel of the second switch 32, the threshold of the second switch 32 is deeper than the threshold of the first switch 37. Become.
- the first switch 37 and the second switch 32 having different impurity doses can be manufactured by, for example, the following method. That is, in the normal process of forming a thin film transistor, In addition, the number of times of doping the channel region of the first switch 37 with the impurity is made larger than the number of times of doping the impurity of the channel region of the second switch 32. For example, first, the channel regions of the first switch 37 and the second switch 32 are doped with impurities. Next, the channel region of the second switch 32 is masked using a photo resist. Subsequently, the channel region of the first switch 37 is further doped with impurities. In this way, the dose of the donot to the channel of the first switch 37 is larger than the dose of the p-type dopant to the channel of the second switch 32.
- the dose amount between the switches is 1 XI o U cm—2 to 5 ⁇ 10 1 1 cm—preferably 2 different.
- the second switch 32 can be more reliably turned off before the first switch 37 is turned off.
- the threshold value of the first switch 37 and the threshold value of the second switch 32 can be made different by other methods.
- FIG. 6 is a cross-sectional view schematically showing an example of a structure that can be employed for the first switch.
- FIG. 7 is a cross-sectional view schematically showing an example of a structure that can be employed for the second switch.
- the first switch 37 shown in FIG. 6 is a top-gate type p-channel thin film transistor.
- This thin film transistor includes a semiconductor layer in which a source S and a drain D and a channel Ch interposed therebetween are formed. Above channel C h A gate TG is arranged on the gate insulating film GI.
- the gate TG is covered with an interlayer insulating film II, and a source electrode SE and a drain electrode DE are formed on the interlayer insulating film II.
- the source electrode SE and the drain electrode DE are connected to the source S and the drain D via through holes formed in the good insulating film GI and the interlayer insulating film II, respectively.
- the second switch 32 shown in FIG. 7 is similar to the first switch 3 shown in FIG. 6 except that the back gate BG is arranged below the channel Ch via the insulating film BI. It has the same structure as 7. A bias for increasing the threshold of the second switch 32 is applied to this pack gate BG.
- the voltage between the back gate BG of the second switch 32 and the source S is set to about +0.2 V to +1.0 V.
- the threshold value of the second switch 32 becomes the threshold value of the first switch 37. It gets deeper. Therefore, also in this case, the second switch 32 can be turned off before the first switch 37.
- FIGS. 6 and 7 show a top-gate type thin-film transistor as an example.
- the bottom gate type thin-film transistor is used as the first switch 37 and the second switch 32. You can use a transistor.
- the threshold value of the second switch 32 becomes deeper than the threshold value of the first switch 37.
- the pack gate here is the control terminal. This is a gate that is arranged to face the element via a gate insulating film and a semiconductor layer.
- the techniques described in the first aspect can be combined with each other.
- a method using a channel length in order to make the threshold value different between the first switch 37 and the second switch 32, a method using a channel length, a method using the number of channels, and a method using a dose amount of impurities. And two or more methods using the backgate structure may be combined.
- the threshold values of the first switch 37 and the second switch 32 are set so that the second switch 32 is turned off before the first switch 37. Was different. Such switching lags can be created in other ways.
- FIG. 8 is a plan view schematically showing an organic EL display according to the second embodiment of the present invention.
- This organic EL display 1 has the same structure as the organic EL display 1 in FIG. 1 except for the following structure. That is, in the organic EL display 1 of FIG. 8, the first switch 37 and the second switch 32 have the same structure. In addition, in this display 1, the control terminal of the first switch 37 is connected to the scan signal line 36 via the delay element 39, and the control terminal of the second switch 32 is connected to the scan signal. Directly connected to lines 36. Note that the organic EL display 1 in FIG. 8 can be driven by the same method as that described with reference to FIG. 4 in the first embodiment.
- FIG. 4 is a diagram showing an example of a signal waveform.
- the delay element 39 plays a role of delaying the switching of the first switch 37.
- the delay element 39 sets the rising and falling of the scanning signal Scan input thereto to be gentle to the control terminal of the first switch 37. Is output.
- the control signal of the second switch 37 is supplied with the same scan signal Scan input to the delay element 39. Therefore, if the threshold value of the first switch 37 is substantially equal to the threshold value of the second switch 32, when the scanning signal line driver 12 supplies an OFF signal to the scanning signal line 36, The second switch 32 is turned off before the first switch # 37.
- the second switch 32 can be turned off before the first switch 37. Therefore, according to this embodiment, it is possible to realize the organic EL display 1 in which the gradation collapse and the in-plane unevenness of the luminance are suppressed.
- delay element 39 Various elements can be used as the delay element 39.
- FIG. 10 is an equivalent circuit diagram showing an example of a pixel circuit that can be employed in the organic EL display of FIG.
- a resistance element 39 R is used as the delay element 39.
- the signal supplied to the control terminal of the first switch 37 is delayed with respect to the signal supplied to the control terminal of the second switch 32.
- a polysilicon layer is used as the resistor element 39R. May be.
- the polysilicon layer used as the resistance element 39 R can be formed at the same time as the drive control element 30 and the polysilicon layers of various switches.
- the resistive element 39 R for example, an n + -type polysilicon layer, a p + -type polysilicon layer, an i-type polysilicon layer, or the like is used as a polysilicon layer. can do.
- the i-type polysilicon layer has the highest specific resistance. Therefore, when the i-type polysilicon layer is used, the switching of the first switch 37 can be changed to the switching of the second switch 32 even if the size of the resistor 39R is reduced. It is possible to sufficiently delay switching.
- the area of the resistive element 39R can be set to about 400 m 2 to 100 ⁇ m ⁇ 2.
- FIG. 11 is an equivalent circuit diagram showing another example of a pixel circuit that can be employed in the organic EL display of FIG.
- a diode 39D connected so as to allow a forward current to flow from the control terminal of the first switch 37 to the scan signal line 36 is used. Use it.
- the ON signal is supplied to the control terminal of the first switch 37 without delay or slightly after the falling of the scanning signal Scan.
- the scanning signal Scan rises, a reverse bias is applied to the diode 39D, and a leak current flows through the diode 39D. Therefore, the OFF signal is supplied to the control terminal of the first switch 37 with a delay from the rising of the scanning signal Scan. Ie In the pixel circuit of FIG. 11 as well, the OFF signal supplied to the control terminal of the first switch 37 is delayed with respect to the OFF signal supplied to the control terminal of the second switch 32.
- the diode 39D for example, a diode-connected thin-film transistor can be used.
- a diode 39D is connected between the control terminal of the first switch 37 and the scanning signal line 36, and The gate uses a p-channel thin film transistor connected to the drain.
- the transistor 39D connected in this way functions as a diode.
- the diode 39D can be formed simultaneously with the drive control element 30 and various switches.
- FIG. 12 is an equivalent circuit diagram showing still another example of the pixel circuit that can be employed in the organic EL display of FIG.
- the first diode 39D1 and the second diode 39D2 are used as the delay element 39, and the delay is performed.
- These diodes 39 D 1 and 39 D 2 are connected in parallel between the control terminal of the first switch 37 and the control terminal of the second switch 32.
- the forward direction of the first diode 39D1 and the forward direction of the second diode 39D2 are opposite to each other.
- the delay time of the ON signal to be supplied to the control terminal of the first switch 37 is equal to the delay time of the first diode 39D. It can be adjusted according to the forward resistance of 1.
- the delay time of the OFF signal to be supplied to the control terminal of the first switch 37 can be adjusted according to the forward resistance of the second diode 39D2. You. That is, the delay time of the OFF signal can be set independently of the delay time of the ON signal. Therefore, when the structure shown in Fig. 12 is adopted for the pixel circuit, design with higher freedom is possible.
- diodes 39 D 1 and 39 D 2 for example, a thin film transistor connected to a diode can be used.
- a diode 39D1 is connected between the control terminal of the first switch 37 and the scan signal line 36, and the gate is connected to the drain.
- a channel thin-film transistor is used.
- the second diode 39D2 is connected between the control terminal of the first switch 37 and the scanning signal line 36, and the gate is connected to the source.
- the P-channel thin-film transistor is used.
- the transistors 39 D 1 and 39 D 2 connected as described above function as diodes having forward and reverse directions.
- the diodes 39D1 and 39D2 It can be formed simultaneously with the switch.
- the techniques described in the second aspect can be combined with each other.
- a resistor in which a resistance element 39R and a diode 39D are connected in series may be used.
- a resistance element 39 R and diodes 39 D 1 and D 2 connected in parallel with the resistance element 39 R may be used.
- the techniques of the embodiments can be combined with each other. That is, as described in the first embodiment, the threshold values of the first switch 37 and the second switch 32 are made different, and the delay element 39 described in the second embodiment is added to the pixel circuit. May be installed.
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Theoretical Computer Science (AREA)
- Computer Hardware Design (AREA)
- Electroluminescent Light Sources (AREA)
- Control Of Indicators Other Than Cathode Ray Tubes (AREA)
- Control Of El Displays (AREA)
- Thin Film Transistor (AREA)
Abstract
Description
Claims
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP03774043A EP1571643A4 (en) | 2002-11-20 | 2003-11-19 | ORGANIC ELECTROLUMINESCENT DISPLAY AND ACTIVE MATRIX SUBSTRATE |
JP2004553200A JP4619793B2 (ja) | 2002-11-20 | 2003-11-19 | 有機elディスプレイ |
US11/133,273 US20050212448A1 (en) | 2002-11-20 | 2005-05-20 | Organic EL display and active matrix substrate |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2002336920 | 2002-11-20 | ||
JP2002-336920 | 2002-11-20 |
Related Child Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US11/133,273 Continuation US20050212448A1 (en) | 2002-11-20 | 2005-05-20 | Organic EL display and active matrix substrate |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2004047064A1 true WO2004047064A1 (ja) | 2004-06-03 |
Family
ID=32321824
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2003/014705 WO2004047064A1 (ja) | 2002-11-20 | 2003-11-19 | 有機elディスプレイ及びアクティブマトリクス基板 |
Country Status (6)
Country | Link |
---|---|
EP (1) | EP1571643A4 (ja) |
JP (1) | JP4619793B2 (ja) |
KR (1) | KR100637304B1 (ja) |
CN (1) | CN1711577A (ja) |
TW (1) | TWI277045B (ja) |
WO (1) | WO2004047064A1 (ja) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2008032861A (ja) * | 2006-07-27 | 2008-02-14 | Sony Corp | 表示装置 |
Families Citing this family (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
TWI478134B (zh) * | 2006-05-31 | 2015-03-21 | Semiconductor Energy Lab | 顯示裝置、顯示裝置的驅動方法、以及電子設備 |
KR100824854B1 (ko) | 2006-12-21 | 2008-04-23 | 삼성에스디아이 주식회사 | 유기 전계 발광 표시 장치 |
KR100952836B1 (ko) * | 2008-07-21 | 2010-04-15 | 삼성모바일디스플레이주식회사 | 화소 및 이를 이용한 유기전계발광 표시장치 |
TWI437551B (zh) | 2011-10-24 | 2014-05-11 | Au Optronics Corp | 影像防窺方法 |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2001147659A (ja) * | 1999-11-18 | 2001-05-29 | Sony Corp | 表示装置 |
JP2002514320A (ja) * | 1997-04-23 | 2002-05-14 | サーノフ コーポレイション | アクティブマトリックス発光ダイオードピクセル構造及び方法 |
Family Cites Families (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB9812742D0 (en) * | 1998-06-12 | 1998-08-12 | Philips Electronics Nv | Active matrix electroluminescent display devices |
WO2001006484A1 (fr) * | 1999-07-14 | 2001-01-25 | Sony Corporation | Circuit d'attaque et affichage le comprenant, circuit de pixels et procede d'attaque |
JP2003195815A (ja) * | 2000-11-07 | 2003-07-09 | Sony Corp | アクティブマトリクス型表示装置およびアクティブマトリクス型有機エレクトロルミネッセンス表示装置 |
JP3951687B2 (ja) * | 2001-08-02 | 2007-08-01 | セイコーエプソン株式会社 | 単位回路の制御に使用されるデータ線の駆動 |
JP5070666B2 (ja) * | 2001-08-24 | 2012-11-14 | パナソニック株式会社 | 画素構成およびアクティブマトリクス型表示装置 |
US7209101B2 (en) * | 2001-08-29 | 2007-04-24 | Nec Corporation | Current load device and method for driving the same |
JP4603233B2 (ja) * | 2001-08-29 | 2010-12-22 | 日本電気株式会社 | 電流負荷素子の駆動回路 |
-
2003
- 2003-11-19 WO PCT/JP2003/014705 patent/WO2004047064A1/ja active Application Filing
- 2003-11-19 KR KR1020057009013A patent/KR100637304B1/ko active IP Right Grant
- 2003-11-19 CN CNA2003801034005A patent/CN1711577A/zh active Pending
- 2003-11-19 EP EP03774043A patent/EP1571643A4/en not_active Withdrawn
- 2003-11-19 JP JP2004553200A patent/JP4619793B2/ja not_active Expired - Fee Related
- 2003-11-20 TW TW092132565A patent/TWI277045B/zh not_active IP Right Cessation
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2002514320A (ja) * | 1997-04-23 | 2002-05-14 | サーノフ コーポレイション | アクティブマトリックス発光ダイオードピクセル構造及び方法 |
JP2001147659A (ja) * | 1999-11-18 | 2001-05-29 | Sony Corp | 表示装置 |
Non-Patent Citations (1)
Title |
---|
See also references of EP1571643A4 * |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2008032861A (ja) * | 2006-07-27 | 2008-02-14 | Sony Corp | 表示装置 |
Also Published As
Publication number | Publication date |
---|---|
KR20050085053A (ko) | 2005-08-29 |
KR100637304B1 (ko) | 2006-10-23 |
EP1571643A4 (en) | 2009-11-25 |
EP1571643A1 (en) | 2005-09-07 |
TWI277045B (en) | 2007-03-21 |
CN1711577A (zh) | 2005-12-21 |
JP4619793B2 (ja) | 2011-01-26 |
JPWO2004047064A1 (ja) | 2006-03-23 |
TW200414804A (en) | 2004-08-01 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US11568810B2 (en) | Display apparatus | |
US10529280B2 (en) | Display device | |
JP7359701B2 (ja) | 表示パネルおよび表示装置 | |
JP6031954B2 (ja) | 発光素子、表示装置及び電子機器 | |
US7333079B2 (en) | Organic EL display and active matrix substrate | |
US8749460B2 (en) | Image display device having a reset switch for setting a potential of a capacitor to a predetermined reference state | |
US10720102B2 (en) | Driving method for display device | |
KR101325789B1 (ko) | 반도체 디바이스 | |
TW200535766A (en) | Display device, data driving circuit, and display panel driving method | |
WO2021184893A1 (zh) | 像素电路及其驱动方法、显示基板、显示装置 | |
JP2007316510A (ja) | アクティブマトリクス型表示装置 | |
CN113823639B (zh) | 显示面板及显示装置 | |
KR20210022807A (ko) | 화소 및 이를 구비한 표시 장치 | |
KR20060096857A (ko) | 표시 장치 및 그 구동 방법 | |
US9053666B2 (en) | Display device and electronic apparatus | |
US20050212448A1 (en) | Organic EL display and active matrix substrate | |
US10147360B2 (en) | Rugged display device architecture | |
JP2004246349A (ja) | 有機elディスプレイ及びアクティブマトリクス基板 | |
JP4619793B2 (ja) | 有機elディスプレイ | |
US8094110B2 (en) | Active matrix display device | |
TWI254266B (en) | Active matrix type display apparatus | |
JP2004341352A (ja) | アクティブマトリクス型表示装置 |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AK | Designated states |
Kind code of ref document: A1 Designated state(s): CN JP KR SG US |
|
AL | Designated countries for regional patents |
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 IT LU MC NL PT RO SE SI SK TR |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2004553200 Country of ref document: JP |
|
121 | Ep: the epo has been informed by wipo that ep was designated in this application | ||
WWE | Wipo information: entry into national phase |
Ref document number: 20038A34005 Country of ref document: CN |
|
WWE | Wipo information: entry into national phase |
Ref document number: 1020057009013 Country of ref document: KR |
|
WWE | Wipo information: entry into national phase |
Ref document number: 11133273 Country of ref document: US |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2003774043 Country of ref document: EP |
|
WWP | Wipo information: published in national office |
Ref document number: 1020057009013 Country of ref document: KR |
|
WWP | Wipo information: published in national office |
Ref document number: 2003774043 Country of ref document: EP |