TWI276032B - Active organic light emitting diode driving circuit - Google Patents

Abstract

The present invention relates to a driving circuit structure for an active organic light emitting diode (OLED) display. To provide uniform display, this invention employs a 3T1C circuit structure in the display panel pixel area and adds extra data capacitors connecting to all the illuminating pixels; the data capacitors are located on one side of the display panel. Besides, cathodes to the OLED on each pixel are all connected to one end of a transistor Moc on the outside of the display panel. In this kind of arrangement, the aperture ratio of the illuminated pixel of the display panel device can be greatly improved. Moreover, an additional by-pass current transistor in parallel with data capacitors in the outside of the display panel can automatically tore current in response to the initial level of voltage and thus enhance the contrast ratio of the display panel pixels.

Description

1276032 — V. Description of invention (1) [The field of creation] Active ΐ ί 日! About the structure of an organic light-emitting diode component, especially the right-hand type 1 π ^------ In order to improve the uniformity and contrast of the illumination of the active organic light-emitting diode element. [Creation background] The passive matrix has 趟H, k, and the way is #一.昼 岁 与 驱动 与 一 一 一 一 一 一 一 一 一 一个 一个 一个 一个 一个 一个 一个 一个 一个 一个 一个 一个 一个 一个 一个 一个 一个 一个 一个 一个 一个 一个 一个 一个 一个 一个 一个 一个 一个 一个 一个 一个 一个 一个 一个 一个 一个 一个 一个 一个兮 chain - w 士 夕 显 显 ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( 〇lumndata generat〇r) and column selection generator i2〇(r〇w seiect generator). In the case of 眚口仏 ^ ^ ., the display is done, each column 1 3 0 ( row 1 i ne ) will be opened sequentially, and each, u _ 曰 会 will also be based on the data input beat 14 (3 ( Column Hnes) The painting is dry - the brightness is displayed by the value of each Η. In the passive matrix display 1 ^ ^ a column is opened and then the next column is opened, the data generator is parallel IK, :: column painting The prime is first entered into the shellfish by the different rows, and then in the next rame time (I rame time) imitation: owe,,, to say, the passive matrix is dry and dry, the input value is displayed. In other words, a certain period of time is obvious;: 2:: Lennon is only in the entire picture time in the entire picture time = interesting and = dynamic matrix display is a few thousand are in the display state ^ , 斤 - Door Patent Ν 0 · 61573 56 ). In this patent, as shown in the second figure, it is -+

,,,,,,,,,,,,,,,,,,,,,,,,,,,,

Page 4 1276032 V. Description of the invention (2) Crystal Μ 1 2 3 0 ; - Drive transistor Μ 2 2 4 0, a data line 2 1 〇 (data line), a select line 220 (select line), a storage capacitor Cs 250 ' A power supply Vdd 270 (power supply) and an organic light-emitting diode 260 (OLED). In each element of the display panel, if the gate-to-source starting voltage (thresh〇ld vo It age) of the driving transistor M2 is different, it will cause a difference in the current passing through the 〇LED, which is a current. Differences can cause unevenness in the brightness of the panel display. The reason why the initial voltage of the driving gate to the source is uneven, which causes a difference in driving current, is mostly caused by improper control of the quality of the transistor manufacturing. The improvement of the display unevenness due to the difference in the starting voltage of the transistor has been proposed by a conventional patent, such as U.S. Patent No. 6229506. In this patent, a 4T2C structure of two capacitors with two capacitors can compensate for the starting voltage of the drive transistor in each pixel to improve the uniformity of luminance of the pixels. As shown in the third figure, the pixel structure has a data line 310 (data Hne), a scan line 320 (scan line), a power supply Vdd line 305, an AZ line 390 and an AZb control line 395, and four transistors 33 〇. 34〇, 37〇, 350, auto-zero capacitors 355 and 380 with an 0LED 360. In this pixel structure, compared to US Patent N0.6 1 57356, the added two transistors and one capacitor, together with the waveform and drive timing of Figure 4, can compensate for the start of the drive transistor M2 340. Voltage to improve the uneven illumination of the pixels. However, since the added components will occupy too much space in the layout, the pixel aperture ratio is caused.

1276032 V. Loss of invention (3). What's more, since the organic light-emitting diode (〇LED) still emits current through the auto-zero phase, the light is not originally intended, which causes the display of the pixel. The reduction. Figure 4 is a timing diagram of the control signal AZ line, AZb line, scan line and data line driving the circuit structure of Figure 3. The timing can be divided into an auto-zero start voltage phase and a data write phase. Before the automatic zeroing phase is executed, the M workers 330, Μ3 370 are in the state of "off", and the states of Μ2 34 〇 and 144 35 〇 are in the "open" state. At this time, the current flowing through the OLED is the electric current and current of the previous kneading time. After a short time, the M1 330 is turned on, and then the M3 37 is connected to the drain and the gate of the M 2 3 4 G. Its function is like - two v, 350,, ", because the interpole voltage of 2 340 will increase γ, _2 electric two or two V factory will be connected (four) 370 will accommodate C2 355, so the completion of the electricity start date ^ Pressure data is recorded in the electric work. Therefore, the next data writer _\曰曰^ initial voltage auto-zeroing the starting voltage of the moving body causes the unevenness of the surface. I will not care about the 2 crystal. The purpose of the invention is to provide a new, The uniformity of the soil °, while increasing the organic illuminant ^ improve the non-proportion of luminescence. & body parts illuminate in alizarin Another object of the present invention is to provide a comprehensive display of the organic light-emitting diode element of the ^= improving the contrast of the luminescence

1276032 V. INSTRUCTIONS (4) The above problems can be improved by the following organic light-emitting diode element halogen structure. —” The present invention first proposes a new active organic light-emitting diode driving method capable of uniform display, and adopts a 3 T1 C structure of 3 transistors and a capacitor in each pixel design and adds an additional data capacitor. The capacitor is connected to the luminescent pixel' and the location of the data capacitor layout is outside the display panel pixel array region 2. In addition, the OLED elements in each pixel have their cathodes connected together and connected to the Moc One end of the transistor, and the position of the m〇c transistor is also outside the display panel. With this architecture, the problem of uneven illumination of the pixels and the problem of the luminous aperture ratio can be improved. In another example, An additional shunt transistor Mby is arranged in parallel with the data capacitor in the outside of the display panel, both of which are placed in the data generation state region (data generat〇r regi〇n), and the function of the Mby transistor is added, and the main function is to reduce 〇LED components in the automatic storage (aut〇-st〇re) start private pressure P from & day guard current, which can increase the display contrast of the display panel. The other purposes and functions of this creation are matched with the following diagram It will be better understood after the further explanation. [Explanation of the embodiment] The factory has an active matrix OLED 3T1C pixel structure 50 0 as shown in Figure 5 f. The ΐ crystal of the ΐ ΐ crystal can be used for low temperature polycrystalline lithography (LTPS) film. Implemented in a transistor or / film transistor. Although the general halogen architecture is

1276032 V. DESCRIPTION OF THE INVENTION (5) A thin film transistor and an organic light emitting diode element are constructed. In fact, in the present invention, other transistors such as M〇s may be used for the transistor. In FIG. 5, the 3T1C halogen structure 500 includes three PMOS transistors 530, 540'550, a storage capacitor Cs 555, an OLED 560 (organic light emitting diode element) and a transistor M〇c 565. The scan line 520 is connected to the gate of the transistor 530, the TW line 590 is connected to the gate of the transistor 550, the data line 51 is connected to the drain of the transistors 550 and 530, and the power supply vdd line 505 is connected to the transistor. The source of 540 and one end of storage capacitor Cs 555, and the other end of storage capacitor Cs is connected to the source of transistor 53〇 and the gate of transistor 54〇. One end of the OLED 560 is connected to the drain of the transistor 54A and the source of the transistor 55A, and the other end of the OLED 560 is connected to a collecting transistor M〇c 565. - Figure 6 shows a schematic diagram of the 3T1C pixel and display panel of the present invention. In the present embodiment, the transistor 53A of all the pixels in one pixel and the drain of the transistor 5j0 are connected in the present invention. The data capacitance Cd 602 in the data generator area 6〇8, and the position of the data capacitance Cd 6〇2 layout is outside the display panel pixel array area. In addition, the 叽(10)"^ element in each pixel has its cathodes connected together and connected to one end of the M〇c transistor 565, and the position of the Moc transistor 565 is also outside the display panel. Not in the pixel array area. In summary, the display panel structure includes five parts. The data generator area 608 is located at the periphery of the pixel array, and the selection generator 52 is located at the periphery of the pixel array, and the tw control line 59 The 〇 is located on the periphery of the pixel array, and the M〇c transistor 565 is located at the periphery of the pixel array and the pixel array is located at the center of the display panel. The seventh figure is a timing diagram for driving the control signal of the figure six architecture, and the timing is 1276032. 6) can be divided into automatic storage start voltage phase (aut〇_st〇re thresh〇ld voltage period), scan (data input) and display phase. In the automatic, ^ 5 starting voltage phase, scanl to scan N signal It will start with, and high (Ml is off) and then become, and low eve (Ml is open). in

Scanl, scan2, scan3,...scan N is the stage of low and low, TW 7〇5 是 is first, high '', then low, then high, and 0C 707 is first, low ,, then, Gao Xi; when the TW 7〇5 signal is, low, and the 〇C 707 signal is, low ", the current will pass from Vdd 5〇5 through M2 540 and 0LED 560 to M〇c The bungee of 565. Therefore, the Cs capacitor 555 records a voltage value which depends on the characteristics of the M2 540 and the organic light emitting diode element C^ED 560. On the other hand, when the Tw 7〇5 signal is low ' oc signal is, high, Moc 565 is , and the current is off, Cs 555 will automatically store the starting voltage of m2 540. As for the broom (data In the input phase, the scanning line is sequentially changed from the first to the Nth apostrophe, the sorghum to the low squat, and the data signal change amount is coupled to the Cs 5 55 via Cd 602, M1 530, and This coupling voltage will be added to the initial voltage of M2 540 originally stored on Cs 555 to become the true data voltage signal. When all the scanning lines are scanned, it will enter the display phase, at this time 〇c 707 The signal will change from , , high "low, /, so Moc 565 will be turned on. Therefore, the required current depends on the difference between the source and the gate of the transistor ,2, from Vdd 5 0 5 to Μ 2 5 4 0 to the light. The diode 560 allows the light-emitting diode 560 to emit light more uniformly. Thus, the current through the 0 LED 560 will not be related to the initial voltage of the M2 540, but will only be related to the input data signal.

1276032 V. INSTRUCTIONS (7) The advantage of the above architecture is that the data capacitor 602 is located in the data generator area 608, and the transistor Moc 565 is also located outside the pixel array. Through this arrangement, the pixel aperture rate problem will be effectively improved. Even more, the entire pixel array configuration in the present invention will only require the scan line 520, the data line 510, the Vdd line 505 and the TW control line 590. The complexity of display panel control. In another preferred embodiment, as shown in the eighth and ninth diagrams, the pixel architecture is similar to the fifth and sixth diagrams; the only difference is that an additional shunt is placed outside the display panel. The transistor Mby 808 is placed in parallel with the data capacitor Cd 602 and placed in the data generator area 6〇8. The function of adding Mby transistor 808 is mainly to input the lower voltage signal through the *Mby8〇8 to the anode of OLED560 in the auto-store initial voltage stage, so that the auto-store can be reduced. The initial voltage phase flows through the current of the OLED 560 component, which increases the display contrast of the display panel pixels. The nine-figure diagram is a timing diagram for driving the eight signals. The timing is divided into automatic storage start voltage phase, scan (data input) and display phase. During the automatic storage start voltage phase, the scan 1 to scan N signals will start to be high (Ml is off) and then become, low " (Ml is on). In scanl, scan2, scan3, ... scan N is , In the low-lying stage, the Dingjie 90 5 signal is first, high, and then, low, and then changed to, high, /; and 〇 (: 9〇7 signal is first, low, then, high ", BY 909 is, high" and then, low, and high; when TW 90 5 signal is, low " and 9〇, 7' signal is low and BY 90 9 is, low, Lower pressure data signal

Page 10 1276032 V. INSTRUCTIONS (8) Input to the anode of 0LED560 via Mby 808. Therefore, only a small current flows through the OLED 560 to the drain of the Moc 565. Wait until TW 905 is , low " '0C is ' , high ' / ' BY is also , ' Gao Xi , Moc 565 and Mby 8 0 8 is off current ' At this time C s capacitor automatically stores the starting voltage of Μ 2 Although the body can also be 3T1C 1 050, 1 065, M2 540 pays for the crystal in an attempt to have the same effect. However, the foregoing illustration of the invention is a PM0S transistor, in fact, the crystal is used for NM0S transistor, but its correlation The voltage is inverted. In the figure, the ten-dimensional structure 1 0 0 0 contains three NM0S transistors 1 0 30, 1 040, a storage capacitor Cs 1 055, an 0LED 1 0 6 0 with a transistor Moc The biggest difference in Figure 5 is to replace the PM0S and the change of the Moc position of the transistor with NM〇s M2 1 040. In addition, this structure can simultaneously complement the initial voltage values of M2 54 0 and 〇LED 1060. In order to explain the preferred embodiment of the present invention, it is not a limitation of any form of creation, that is, any modification or alteration relating to the creation made under the terms of the creation is still protected by the intention of the creation. category.

1276032 Schematic description of the diagram The first figure is a passive matrix organic light-emitting diode display. The second figure 2T1C pixel circuit diagram. The third figure 4T2C pixel circuit diagram. The fourth figure 4T2C drive signal timing diagram. Fig. 5 is a diagram showing the circuit structure of the 3T1C pixel in the present invention. Fig. 6 is a schematic view showing a 3T1C pixel and a display panel in the present invention. Figure 7 is a timing diagram of the 3T1 C drive signal in the present invention. Figure 8 is a schematic diagram of the drive circuit of the present invention incorporating an additional transistor in parallel with the data capacitor in the data generator region. Figure 9 is a timing diagram of the driving signal of the driving circuit of the present invention after driving an additional transistor in the data generator area. The tenth figure shows the circuit structure diagram of the NM0S transistor in the 3T1C pixel of the present invention. [Component Symbol Description] 100 Passive Matrix Organic Light Emitting Diode Display 110 Row Data Generator 120 Column Direction Selector 130 Column Line 14 0 Line Line 160 Display Element 210 Data Line 22 0 Select Line

Page 12 1276032

Page 13 Simple Description 230 Switching Transistor 240 Driving Transistor 250 Storage Capacitor 260 Organic Light Emitting Diode (OLED) 270 Power Supply 305 Power Supply V dd Line 310 Data Line 320 Scan Line 330 Transistor 340 Transistor 350 Crystal 355 Auto Zero Capacitor 360 Organic Light Emitting Diode (OLED) 370 Transistor 380 Auto Zero Capacitor 400 4T2C Elementary Structure Drive Signal Timing 500 3T1C Pixel Architecture 505 Power Supply 510 Data Line 520 Scan Line 530 Transistor 540 Transistor 550 Transistor 555 Storage Capacitor 1276032 Illustrated Simple Description 560 Organic Light Emitting Diode (OLED) 565 Transistor Μ 〇c 590 TW Line 600 3 Τ1 C 昼 之 显 面板 面板 602 602 Data Capacitor 608 Data Generator 703 Data line 705 TW line 707 OC line 800 3T1C 昼 之 display panel architecture 808 transistor Mby 903 data line 905 TW line 907 OC line 909 BY line 1000 3T1C 昼 架构 architecture 1030 NMOS transistor 1040 NMOS transistor 1050 NMOS transistor 1055 Storage Capacitor 1060 Organic Light Emitting Diode (OLED) 1065 Transistor Moc

Page 14

Claims (1)

曰 '' storage capacitor, the storage capacitor has a first end and a second end, the first source of the body is connected to the first end of the storage capacitor, the first end of the capacitor is connected to a Vdd a second transistor, the second transistor having a gate, a source and a drain, the gate of the second transistor being connected to the source of the first transistor The gate of the second transistor is connected to the first end of the storage capacitor; the source of the second transistor is connected to the Vdd line, and the source of the second transistor is connected to the storage capacitor a second transistor; a third transistor having a gate, a source, and a drain. The gate of the third transistor is connected to the line, the drain of the third transistor Connected to the data capacitor in the data generator area, the first 6. The patent source of the third transistor is connected to the drain of the second transistor; a light-emitting element connecting the source of the third transistor to the anode of the second transistor And a collecting transistor, located on a third side of the display panel, the collecting transistor has a source, a drain and a gate, and the light emitting element in each of the light emitting elements is connected to the collecting electricity The source of the crystal, the gate of the collecting transistor is connected to a control device OC. 2. The driving circuit of claim 1, wherein the illuminating element is an organic light emitting diode element. 3. The driving circuit of claim 1, wherein the second transistor is a PMOS transistor. 4. The driving circuit of claim 1, wherein the data capacitor of the data generator area is a luminescent pixel connected to the display panel. 5. The driving circuit of claim 1, wherein the data capacitor is located in the data generator area, and the data generator area is outside the illuminating pixel area and located on one side of the display panel. 6. The driving circuit as described in claim 1 of the patent scope, the collection Page 16 6. Patent Application Range The transistor is outside the luminescent pixel and is located on one side of the display panel. 7. An active organic light emitting diode driving circuit, comprising: - a data generator area, located on a first side of the display panel, having a plurality of data capacitors, each data capacitor having two end points, wherein one end point Connected to the illuminating pixels on the display panel; - a selection generator, located on the second side of the display panel, and connected to each of the luminescent elements on the panel; a TW line is connected to each of the luminescent elements; wherein the illuminating pixels are located in the center of the display panel, and the illuminating elements comprise: - the first transistor has a gate, a source and a drain, the gate a pole connected to the selection generator, the drain is connected to the data generator area; - the storage capacitor has first and second ends, the source of the first transistor is connected to the first end of the capacitor, The second end of the capacitor is connected to a V dd line or a common electrode; The second transistor has a gate, a source and a drain, the gate of the second transistor being connected to the source of the first transistor, the gate of the second transistor being connected to the gate The first end of the storage capacitor; the third transistor has a gate, a source and a drain, the gate of the third transistor is connected to the TW line, and the drain of the third transistor is connected The data capacitor in the data generator area, the third transistor Page 17 91125192 Λ: _ 曰 Amendment 6, the source of the patent application is connected to the drain of the second transistor; the first end electrode of the first end and the second end element; and, - collection The transistor has a source, a light-emitting element, and is located in each of the light-emitting elements, the light-emitting element having the source of the second transistor is connected to the light-emitting light-emitting element, and the second end is connected to a common Positioned on the third side of the display panel, the collection transistor and a gate, the drain of the second transistor in each pixel is connected to the source of the collection transistor, the collection The gate of the transistor is connected to a control device OC, the drain of which is connected to the Vdd line. 8. The driving circuit of claim 7, wherein the illuminating element is an organic light emitting diode element. 9. The driving circuit of claim 7, wherein the second transistor is an NMOS transistor. 10. The driving circuit of claim 7, wherein the data capacitor of the data generator area is connected to the light-emitting elements. 11. The driving circuit of claim 7, wherein the data capacitor is located in the data generator area, and the data generator area is outside the illuminating pixel area and is located on one side of the display panel. Page 18 No. 91125192_年月日日_i±±_1 2. The driving circuit according to claim 7, wherein the collecting electric crystal is outside the luminescent elements and is located on one side of the display panel. 13. An active organic light emitting diode driving circuit comprising: - a data generator region having a plurality of data capacitors connected in parallel with the shunt transistors, the data generator region being located on a first side of a display panel Wherein the data capacitor has two end points, one end of which is connected to the illuminating pixel on the display panel; - a selection generator located on the second side of the display panel, and each of the illuminating lights connected to the display panel a TW line is connected to each of the illuminating pixels; a plurality of illuminating pixels are located in the center of the display panel, wherein the illuminating pixels comprise: - the first transistor has a gate, a source and a drain, The gate is connected to the selection generator, the drain is connected to the data generator area, a storage capacitor having a first end and a second end, the source of the first transistor being connected to the storage capacitor The first end, the second end of the storage capacitor is connected to a Vdd line or a common electrode; the second transistor has a gate, a source and a drain, and the gate of the second transistor Very connected to The source electrode of the first transistor, the The gate of the first transistor is connected to the first end of the storage capacitor; the source of the second transistor is connected to the Vdd line, and the source of the second transistor is connected to the first portion of the storage capacitor a second transistor; a second transistor having a gate, a source and a drain, the gate of the third transistor being connected to the TW line, the drain of the third transistor being connected to the data generator The data capacitor in the region, the source of the third transistor is connected to the drain of the second transistor; - a light-emitting element, located in each of the light-emitting elements, the third transistor The source and the drain of the second transistor are connected to the light emitting element; and the collecting transistor is located on the third side of the display panel, and has a source, a drain and a gate. The light-emitting element in each pixel is connected to the source of the collecting transistor, and the gate of the collecting transistor is connected to a control device OC. A driving circuit as described in claim 13 wherein the illuminating element is an organic light emitting diode element. 15. The driving circuit of claim 13, wherein the second transistor is a PMOS transistor. 16. The driving circuit of claim 13 wherein the data capacitor of the data generator region and a shunt transistor are connected to the light-emitting elements. Page 20 91125192_年月曰曰修正_6. Patent application scope 1. 7. The driving circuit described in item 13 of the patent application scope is located in the data generator area, the data is located in the data generator area. The generator area is outside the area of the luminescent pixel array to enhance contrast of the illuminating elements. 18. The driving circuit of claim 13, wherein the data capacitor and a shunt transistor are located in the data generator area, and the data generator area is outside the light-emitting pixel array area to improve the opening of the light-emitting element. rate. 19. An active organic light emitting diode driving circuit comprising: - a raw material generating 1 § region having a plurality of lean capacitors connected in parallel with the shunt transistors, the data generator region being located first in a display panel An edge, wherein the data capacitor has two end points, wherein one end is connected to each of the illuminating pixels on the display panel; - a selection generator is located on the second side of the display panel and is connected to the display panel Each of the illuminating pixels; - TW line is connected to each illuminating pixel; and a plurality of illuminating pixels are located in the center of the display panel, wherein the illuminating elements comprise: - the first transistor has a gate and a source And a drain, the gate is connected to the selection generator, the drain is connected to the data generator area; and the storage capacitor has a first end and a second end, the first transistor The source is connected to the reservoir; ^ φ 0 Μ ϋ » a first end of the storage capacitor, the second end of the storage capacitor is connected to a Vdd line or a common electrode; A The electric raft body has a gate 35'-source and a drain, the brother: the gate of the transistor is connected to the source of the first transistor, the gate of the transistor a pole connected to the first end of the storage capacitor; - a second transistor having a gate - a source and a pole, the gate of the third body being connected to the TW line - the third The gate of the transistor is connected to the data capacitor in the tributary generator region. The source of the third transistor is connected to the drain of the second transistor; the mountain-emitting 70 piece is located at the Each of the illuminating pixels has a first and a second end; the source of the second transistor is connected to the first end of the illuminating element; the second end of the illuminating element is connected to a common electrode; And, the collecting transistor is located on the third side of the display panel, and has a source 'a pole and a gate, the second electric in each pixel The body is not connected to the collection electrode of the transistor source, the collection of the gate transistor is connected to a control means 〇C, which brings together the drain of the transistor connected to the line V d d. A driving circuit as described in claim 1 g, wherein the illuminating element is an organic light emitting diode element. 2 1. The driving circuit of the ninth item of the patent application scope is described as 'the second electric crystal is an NMOS transistor. Page 23