TW577017B - Optimization method of voltage-driven multi-transistor pixel design for organic light emitting diode display - Google Patents

Abstract

The present invention is related to the optimization method of voltage-driven multi-transistor pixel design for organic light emitting diode (OLED) display. The invention contains the followings: conducting pixel design in advance, in which the design manner is mainly based on voltage-driven OLED display multi-transistor pixel; conducting theoretical analysis onto the designed voltage-driven OLED display multi-transistor pixel, in which the theoretical analysis uses at least one related mode to obtain a minimum error control target; conducting circuit simulation experiment and comparing it with the optimization result of the minimum control target for the driven OLED obtained from the theoretical analysis steps so as to simulate whether it satisfies the optimization effect; conducting test device circuit layout if it satisfies the optimization effect; otherwise, slightly amending the control target and repeating several times to obtain the design that satisfies the optimization effect.

Description

577017

V. Description of the Invention (1) (1) Technical Field of the Invention The present invention relates to an optimization method for designing a voltage-driven multi-transistor pixel of an organic light emitting diode display (0LED). Optimized design and application method, to keep the minimum current error of voltage drive and the increase of pixel average, so as to improve the display quality.) Background of the Invention: Placement for display of electrical peripherals is an important output “Especially in recent years, the requirements for the appearance of peripheral devices are light, thin, and thin: thin film transistor liquid crystal displays (TFT-LCD) have been widely used, and related thin and short displays and related technologies have been developed. nine. Among them is the driving circuit of the display panel, which is a good indicator of the image quality of the display, which is very important for the entire display. : ’The most widely used matrix type flat panel display is a thin film transistor display (TFT-LCD), which uses a voltage signal to control the conduction of the thin film transistor (TFT) and control the color and brightness of the display. In recent years, there is a new-type display technology of organic light emissión diode (〇led), which uses different energy bands between different kinds of organic molecules. When electrons in different energy bands When combined with an electric hole, different energy will be emitted, that is, it will become a light source of different colors, without the need for a backlight plate (Back Light) used in general TFT-LCD displays, so it can be reduced The overall appearance thickness of the display and reduces manufacturing costs. However, ‘Yue An’ is a newer technology organic light emitting diode

k 577017 V. Description of the invention (2) Organic light emitting diode (AM0LED), the advantages are also self-emission, of course, no backlight module is required, and color filtering is not required Film (Color Fi Iter), has many advantages that are at least equivalent to those of thin film transistor liquid crystal displays, such as: high contrast (100: 1) 'excellent dark and bright image quality, full color, large size It is flexible and flexible, and uses a plastic substrate; not only that, it also has advantages over thin-film transistor liquid crystal displays (TFT LCDs): such as simple structure, high durability, low cost, and low driving voltage (only 3 ~ 9 V), power saving, wide viewing angle above 160 degrees, high brightness (100 cd / m2), fast response speed (10 #s), etc. From this point of view, the active organic light emitting diode (AM0LED) is indeed one of the development potential technologies worthy of attention for the display industry with a promising future. However, in order to steadily improve the image quality of the display, controlling the driving stability of the image pixels is one of the key technologies. The brightness of the organic light emitting diode (0LED) is controlled by the current input to the diode. Therefore, to achieve a uniform display of 咼 quality, a matching motor output is required. Japan mainly includes two types of digital drive and analog drive. However, due to the high circuit complexity of digital drive, the current technology is still mature enough, only published in a few journal papers; and analog drive shell 1 is more common. The mature technology has already appeared in the product, and it can be divided into two types: one is voltage driving (voltage driving / pr0grammUg, the number of transistors is more than two, as shown in Figure 1, and its operation mode is described earlier) In order to use an input voltage (Vin), the transistors 22 and 21 (ie, M1 and M2 shown in the figure) are connected to output a current (10).

Page 5 577017 V. Description of the invention (3) Photodiode 20 'controls the driving stability of image pixels; the other is current driving / programming, the number of transistors is more than four, as shown in Figure 2. There are four transistors, and Figure 3 shows six transistors. The operation mode of the four transistors includes a write scan and erase scan operation, and a current is used to drive a data line 35 'to control each of the transistors 31, 32, 33, and 34 (ie, shown in the figure) Τι, T2, T3, T4) "enable / disablen" state, determine the data writing or erasing of capacitor 36 (c), so that an organic light emitting diode current (I0LED) output drives organic light emitting diode 3 〇, the control of the driving of the image book is stable. The operation of the six crystals is more complicated, but the design is also to use a current to drive a data line (data 1 ine) to control each of the transistors 41, 42, 43, 44, 44 and 45. , 46 (that is, Ml, M2, M3, M4,

The enable / disablen state of Mb2, Mb4) 'enables the current output to drive the organic light-emitting diode 40' to control the driving stability of the image pixels. For the comparison between voltage-driven and current-driven types, the advantages of voltage-driven daylight driving technology include: the existing tn / stn type 'amorphous Si licon' and polycrystalline silicon ( p〇ly silicon) The thin film transistor liquid crystal display industry can directly support; and the number of thin film transistors is less than four, generally less than four, so the design and layout is simpler and less complicated, and the yield is increased; finally, The aperture ratio is high, so it has a large brightness. However, it has the disadvantages that the variability of the anti-process is not good enough, the application range is narrow, and the high current error also causes serious phenomena such as image unevenness. However, the point of current-driven daylight driving technology is

Page 6 4577017 V. Description of the invention (4) Amorphous si transistor liquid crystal display film The number of transistors is more complex than the design and layout and the party degree is low. In summary, although the conventional mobile technology has various It is still not perfect. Because of technology, not only must the organic hair design be optimized to ensure good results, but generally TN / STN type, amorphous silicon and polycrystalline silicon film However, the device industry cannot directly support it; and it is designed to be much thinner (generally four to seven), so the degree of increase in impurity is greatly reduced; finally, the aperture ratio is low, and the analog drive is voltage-driven Or it has the advantages of current drive ', but it also has its insurmountable disadvantages. This invention is to keep the advantages of voltage-driven pixel drive, and to improve the existing disadvantages to achieve more light-emitting diode displays. Voltage-driven multi-transistor search method. Once the 'mechanism of the pixel crystal is raised, the effect of the reduction, the organic light-emitting diode' provided a day-time design 'can also reach the image display products, a brief description of the invention (three) invention: The main purpose of the invention: The voltage-driven multi-purpose special-designed optimization mold of the display has been designed to achieve the optimal display effect. With the advantage of the current error, the improvement is achieved. In order to achieve the foregoing objective, an optimization method for the design of an organic light emitting diode is implemented. The actual circuit layout is then carried out, and the display can be directly completed. The organic light emitting diode display optimization method can not only guarantee the low-quality purpose of the 'Amami current drive type'. Provide an organic light-emitting diode Page 7 577017 V. Description of the invention (5) The optimization of the daylight element design of the voltage-driven multi-transistor of the body display is completed by the following steps: (a) The daylight element design and design method It is based on voltage-driven phase-diode display multi-transistor pixels as the main body; (b) theoretical analysis of the designed voltage-driven organic light-emitting diode / multi-transistor pixels, the theory The analysis system uses the to-connect mode to transmit a minimum error (min 丨 mumerr 〇r (control factor); (c) carry out circuit simulation experiments, the minimum error of the organic light-emitting diode made by the above theoretical analysis steps Control the best results of the target, make a comparison judgment, and simulate whether the optimization effect is satisfied. When step (C) simulates the optimization effect, the voltage-driven type of the organic light-emitting diode display of the test element is more. The electric crystal bone design circuit layout (testkey layout); and if the simulation effect is not optimized, it can include a step, then modify the control slightly and repeat several Steps (a) to (c) to obtain a design that is optimized for small error control targets. ≫ Where optimization refers to the design of the organic light-emitting diode display type multi-transistor daylight design can reach the lowest The effect of current error, high average sentence, etc. In order to allow your review committee to have a better understanding and understanding of the purpose, special steam and the invention of the present invention, we are pleased to cooperate with the details of the drawings \ er Yuehou Hou ·· σ (5) Details of the invention Explanation ·· Methods, I light-emitting indicator. Less one) Controlled driving effect 0 line measurement I pixels are the most standard: the most: the driving efficiency is improved as B1

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577017

V. Description of the invention (6) The present invention is to use the voltage-driven pixel driving technology, not only to retain its advantages, but also to improve the existing disadvantages. 'Organic light-emitting for better results. The optimization method of the voltage-driven multi-transistor daylight design improves the display quality. Please refer to FIG. 4. FIG. 4 is a schematic diagram of a preferred embodiment of a method for optimizing a pixel design of a voltage-driven multi-transistor of an organic light emitting diode display of the present invention. Started with pixel design (pixel design,) 'Setting 2 method is based on voltage-driven organic light-emitting diode display multi-transistor daylight as the main body, the number of transistors can be, but not limited to, more than two, as usual 5 The leaflet is between two and four, which is to use an input voltage (V 丨 n,) to connect the right dry transistor to output a current (Ιο) to drive the organic diode to control the image. The driving is stable, which is the design of the general voltage-driven multi-transistor pixel as described in the description of the present invention. Of course, the number of transistors and the design of the organic light-emitting diode are designed according to various practical requirements. Anyone who knows this art well can It is easy to design, because it is not the focus of the present invention, it will not be repeated here. The following is one of the key points of the present invention. The theoretical analysis of the above-designed voltage-driven organic light-emitting diode display multi-transistor celestial element includes the following steps: a. The mode of connection between the output current (I 〇) and the input voltage (Vin) driving the organic light emitting diode funi:

Io = fun l (Fin) ^ μ〇οχΨ / L (Vgs-Vi) ms where ‘I 〇: output current driving organic light emitting diode

Won

Vin Cox WL Vgs Vt Wheel-in voltage Unit width of capacitor transistor per unit area (unlimited unit) Length of transistor (unlimited unit) The voltage of the transistor and the voltage drop of the body gate and the source are clever. The voltage drop of the source electrode (Vin this) is related to the continuous mode. The function is to correlate the output current (10) with the input voltage: =; =: current =: input voltage (heart) production fh, eight applications Among them, we cannot list them one by one here. The electron mobility ratio (M0bility, represented by #) can be used. Modular ^: the value correlation mode 'and the correlation of the change value of the transistor voltage ^ = η〇 + Αη 〃, // · 电子 电 率 总值 # 〇: Initial value of electron mobility △ #: Change value of electron mobility vt · Total voltage value of transistor Vto: Initial value of voltage of transistor △ vt · Variance value of voltage of transistor Electronic movement 577017 V. Description of the invention (8) The value 'and the related explanation of the change value of the transistor voltage, the above formula is just one example. (C) Design a correlation mode between the change value of the output current driving the organic light-emitting diode, the change value of the electron mobility, and the change value of the voltage of the transistor fun2: Δ / ο zz fun 2 (A μ ^ Αη) =

Cox 孖 / LVds (-μ〇 ^ j / f + ygS-μ yt〇- A // Δ Vi) where '△ I ◦: output current change value of the driving organic light-emitting diode △ # · electron mobility change value △ vt: voltage change of transistor Cox: capacitance per unit area w: width of transistor (unlimited) L · length of transistor (unlimited) V ds · voltage drop between transistor drain and source: Initial value of electron mobility Vgs · The voltage drop between the gate and source of the transistor The function of this connection mode is to change the value of the output current that drives the organic light emitting diode to the value of the electron mobility and the voltage of the transistor The connected model acts as a connected interpreter. (d) ϋ 2 The above connection mode can obtain a current change value (△! 〇) for driving the organic light-emitting diode, and the output current change value ΔΙ〇 is the contro factor of the control target of the minimum error. , That is, for driving organic light emitting diodes,

577017

V. Description of the invention (9) Optimized expression for controlling the driving stability of image pixels. After the theoretical analysis is completed, a circuit simulation experiment is continued. A circuit simulation software, such as a simulatiQn program with Integrated circuit Emphasis (spice), is used to drive the organic light-emitting diodes made in the above theoretical analysis steps. The simulation results of the optimization of the driving stability of the control of the image pixels are compared, and the simulation operations are compared to determine whether they are in line with the optimization results, such as whether the design is optimized, the minimum current error is reduced, and the average sentence level is increased. If the degree is the theoretical analysis of the effect of the electrical control image, the optimization requires the optimization of the organic voltage to achieve the optimal operation when the voltage-driven type of the day-to-day setting is optimized when the stable test component line is driven. When the driving of the light-emitting diode circuit simulation software element is stable, the driving optimization made by the circuit mode 0 is again reached the road layout (called simulation, performing the night crystal drawing, theoretical spectroscopic diode display mode, Therefore, the output of the low current error display is optimal for the driving organic light emitting diode made. As a result, the simulation operation did not reach the optimal starting step. When the pixel design was repeated and the optimization effect was tested to achieve the organic light-emitting diode and control the optimization effect of the simulation operation of the image pixel, The testkey layout is carried out), according to the circuit layout of the element that has reached the most test element organic light emitting diode display. In this way, due to the foregoing steps of analysis, circuit simulation test, etc., the voltage-driven multi-transistor pixels of the indicator have been successfully designed. The circuit layout designed in this mode will definitely improve the uniformity and improve the quality of organic products. Rate and reliability.

Page 12 577017 V. Description of Invention (ίο) Finally, please refer to the difference between the example and the conventional technology; and the horizontal axis indicates the included thin-film transistor pressure-driven organic light-emitting diodes. The variation image of the process is uneven; while the number of electricity is more than four, the opposite sex is better, the low current, the low yield rate, and the low transmittance. For a non-implemented diode display, it is' regardless of polymorphic si 1 (amorphous si 1 The imitated conventional technology, Doming ’s optimized manufacturing process, the light-emitting diode display display is generally low, and even the voltage drive of the display has a small number of transistors, and the existing excellent current error with high light transmittance. Figure 5 'is a schematic diagram of the comparison of the actual results of the optimization method applied in the present invention. The vertical axis of the current is shown as "Tπ" in a single daylight-emitting diode. The figure shows that the traditional The number of transistors in an electric diode display is two to four. The layout is less complex, the yield is high, the light transmittance is not good enough, and the current error is too high. Organic light-emitting diode display transistors, to more than six transistors, although it resists process variation errors to maintain a uniform image, it lacks high complex luminosity, etc. The optimized voltage-driven organic of the present invention The luminous distribution regions are all in the “high current error area (poly si 1 icon) or amorphous silicon cone” display in the illustration, as long as there is a situation where there is no south current error without the invention. However, according to the present invention, it can be clearly seen that the current error of all voltage-driven devices has been reduced to or lower than that of the current-voltage-driven devices. The optimization method not only has the advantages of low design and layout complexity, high yield, and potential, but also can achieve the advantages of current-driven displays such as better resistance to process variation and low holding uniformity, and quality.

Page 13 577017 V. Description of the invention (11) In summary, the present invention is an optimization method for the voltage-driven multi-transistor pixel design of an organic light-emitting diode display, and the optimization using a special design The simulation process has been designed to achieve the optimal effect before the actual circuit layout, and then the layout is performed to directly complete the voltage-driven multi-transistor organic light-emitting diode display that optimizes the display effect. By design, the invention includes at least the following advantages:

1. The invention not only keeps a small number of transistors, but also has the advantages of low complexity, low yield, and high light transmittance in design and layout. It can also achieve better resistance to process variability, low current errors, and image maintenance. The advantages of the uniform and current-driven display are comparable to the current-driven display, and the purpose of improving the image display quality is achieved, so that the product yield, reliability and yield are high. 2. The optimization method proposed by the present invention is clear and not complicated. For those skilled in the art, it can be implemented in accordance with the spirit of the present invention, and the effect can be achieved, and the operation is clear and reliable.

3 · Wide range of applications, the optimization problems that can be solved by the present invention are extremely extensive, such as the flat panel display industry (F 1 at Pane 1 disp 1 ay), liquid crystal display (LCD), active / passive organic light emitting diodes Display (AM / PM0LED) and Low Temperature Polycrystalline Chip (LTPS), Light Emitting Diode (LED), Projector, Semiconductor Conductor, Metal Oxide Semiconductor Sensor Industry (CM〇s Sens 〇r) and thin film process can be implemented by the method of the present invention, and the existing thin film transistor liquid crystal display industry can directly support those. In summary, the present invention discloses an organic light emitting diode display.

Page 14 577017 V. Description of the invention (12) There is no related technical disclosure and method in the field of voltage-driven multi-transistor daylight design. The technical content of the present invention can definitely solve the existing problems in this field. Novelty; the present invention is easy to complete according to the known technology, its efficacy is ^ general and the method principle is non-root step; the technical method and the second f adopted by the present invention have been fully entered into the technical field, and also have industrial use Sex.厅 # The equipment itself belongs to this purpose, and the benefits of patents should be based on patent examination. The reviewing committee that encourages inventions has many years of experience in examination practice and believes in the valuable elements and the spirit of the patent. The patent is really a prayer. Monthly, I hope to approve the appropriation as early as possible ^ The above is only a good example of the present invention & Limitations of the present invention <?? Examples, not the spirit of the invention The artist does not violate the security map of the present invention: it belongs to the scope of the present invention, so this ... the enclosure is based on the scope of patent application described below.

577017 Brief description of the diagram Figure 1 is a schematic circuit diagram of the voltage-driven organic light-emitting diode design of two transistors of general technology. Figure 2 is a schematic circuit diagram of the current-driven organic light-emitting diode design of four transistors of the general technology. Figure 3 is a schematic circuit diagram of the current-driven organic light-emitting diode design of six transistors of the general technology. Fig. 4 is a schematic flow chart of a preferred embodiment of an optimized method for designing a daytime element of a voltage-driven multi-crystal organic light emitting diode display according to the present invention.

Fig. 5 is a schematic diagram showing the comparison of the effectiveness of the embodiment of the optimization method and the conventional technology to which the present invention is applied. Drawing number description: 20, 30, 40-organic light-emitting diodes 21, 22, 31, 32, 33, 34-transistors 41, 42, 43, 44, 44, 45, 46-transistors 3 5 _ lean material line 36 -Capacitance

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Claims (1)

577017 VI. Scope of patent application i. An optimization method for the voltage-driven design of organic light-emitting diode displays. The steps include: (1) Pixel design. The design method is based on Voltage-driven diode-type multi-transistor pixels are the mainstays. (B) Theoretical analysis of the voltage-driven organic light-emitting diodes with multi-transistors is set. The theory is divided into two related modes: A minimum error fmv can be obtained, and the [minimum error] control factor (control factor) is taken as the best basis according to & μ as described in item 丨 of the scope of patent application. The pressure-driven multi-electron daylight design has the most advanced electrical steps for the first two-body / body display. After that, it includes a step; the simulation method described in the order of the theoretical analysis steps is described in the simulation experiment. Make comparison judgments, and simulate whether it is suitable or not 3. As the patent application scope No. 2 Cheng Gu Dehuan t pressure-driven multi-transistor Shu Xin = machine / / diode display electrical steps ⑷When the optimal method of optimizing the quality of the element is simulated ... The step (dl) described in the above description is performed. After the measurement of the effect, a driving multi-transistor can be included. 疋: Organic light-emitting diode display Voltage 4. If you apply for a circuit: Calculate the circuit layout (a layout). The electrical steps of the organic light-emitting diode display described by the voltage-driven multi-transistor inspector (). The said ~ step (d2): after the micro effect / "optimization effect" can further include (a) to (c), change the control target with 杧 J ^ and repeat several steps ^ suitable for optimization Page 17 of the Minimum Error Control Target for Effects Its design. 5. ί :: i ΐ ί! J1: The electricity of the organic light-emitting diode display described by the member (b 1) 5 and δ ten pairs are driven by the input voltage (I, the output current of the pole (1〇) and the input The voltage two ί correlation mode is to set the output current (10) ⑽ as the first correlation interpreter; The formula shows the correlation mode for the change value of the electron mobility (#). The correlation mode of i + i to the change value of the transistor voltage is to separately change the value of the correlation solution, and to make a change of the change value of the transistor voltage 2 " The change value of the output current to drive the organic light emitting diode pair = · move The correlation mode between the rate change value and the voltage change value of the transistor is to explain the correlation mode between the change value of the output current driving the organic light emitting diode and the change value of the electron mobility and the voltage change value of the transistor; (b4 ) A minimum error control target for driving an organic light emitting diode is obtained by using the correlation modes obtained in the above (b 1) to (b3). 6 · As stated in Item 丨 of the patent scope, the electricity of the organic light emitting diode display An optimization method of a pixel driving multi-transistor pixel design, wherein the organic light-emitting diode display includes two to four transistors. 7 · An optimization method for designing a voltage-driven multi-transistor daylight-emitting diode of an organic light emitting diode display as described in item 2 of the stated patent scope, wherein Page 18 577017 Step (c) is the circuit wedge simulation experiment that can be performed by circuit simulation software. • Optimizing the pixel design of the organic light-emitting diode pressure-driven multi-transistor pixel as described in item 7 of the scope of the patent application. " ^ The electrical circuit simulation software system can be integrated circuit simulation software (sp & 9) · Optimization of pixel design of organic light-emitting diodes and one-voltage driving multi-transistor pixels as described in the first patent claim Method,. ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, The Organic Light-Emitting Diode Display: n = the equivalent driving. The optimization method of multi-type multi-element design includes the following steps: (1) Designing the day-time element (a). The design method is based on the voltage-driven diode multi-crystal day-time element. Nine (b) For the voltage-driven organic light-emitting diode designed as described above-'theoretical analysis of the non-hard body Zibegan polyelectron celestial element', the theoretical analysis uses a connection mode to obtain an organic light-emitting diode Input ^ current change value (△ I 〇), this output current change value △ 丨 〇 is the control error of the minimum error (control fact 〇r), as the basis for optimization. II · As described in the 10th scope of the patent application An optimized method for designing a voltage-driven multi-transistor pixel of an organic light emitting diode display. After the step (b), a step (c) can be added to perform a circuit simulation experiment. The driving force of the theoretical analysis steps should be Page 19 577017 VI. Scope of patent application The optimized results of the organic light-emitting diodes are compared and judged to simulate whether the optimization effect is met. 1 2 · The method for optimizing the design of the voltage-driven multi-transistor daylight-emitting diode of the organic light-emitting diode display according to item 11 of the scope of the patent application, wherein the step (c) is after the optimization effect is satisfied It may further include a step (d 1): performing a voltage-driven multi-transistor day-to-day design circuit layout (testkey layout) of the organic light emitting diode display of the test element. 1 3 · The method for optimizing the pixel design of a voltage-driven multi-transistor of an organic light emitting diode display according to item 11 of the scope of patent application, wherein said step (c) is not in accordance with the optimization effect After that, it may further include a step (d2): slightly modifying the control target and repeating the steps (a) to (c) 'several times to obtain the design of the minimum error control target that is consistent with the optimization effect. 14. The method for optimizing the design of the voltage-driven multi-transistor daylight-emitting diode of the organic light-emitting diode display according to item 10 in the scope of the patent application, wherein the theoretical analysis of step (b) may include: (b 1) Design a correlation mode between the output current (丨 〇) and the input voltage (V 1 n) of the driving organic light-emitting diode, so as to correlate the output current (I 〇) with the input voltage (V in) The interpreter; (b2) Designing a correlation mode that can change the value of the electron mobility (#) and a change mode of the transistor voltage, respectively, the change value of the electron mobility and the voltage of the transistor The change value is a related interpreter; (b3) Design the change value of the output current to drive the organic light-emitting diode Page 20 577017… Applicable patent scope Correlation mode of sub-mobility change value and transistor voltage change value: To change the output current change value of driving organic light-emitting diode to electron mobility change value and transistor voltage change value The related mode is used as a related interpreter; (b4) Using the related mode obtained from (bl) to (b3) above, a change value of the output current (ΔI 〇) that drives the organic light emitting diode is obtained. 15 Sergeant • An optimization method for the pixel design of a voltage-driven multi-transistor organic light-emitting diode display as described in item 10 of the scope of patent application, where The organic light-emitting diode display described above includes two to four transistors. _ The method for optimizing the pixel design of the voltage-driven multi-transistor organic light-emitting diode display according to item 11 of the patent scope, wherein step (c) is a circuit simulation experiment of the circuit simulation software. , 17 · An optimization method for the design of daylight-emitting multi-transistor crystal driven organic light-emitting diode displays as described in item 16 of the Shen / Qing Patent Scope, wherein the circuit simulation soft system can be integrated. Circuit simulation software (spice) ° The method for optimizing the design of the U-driven multi-electron daylight-emitting device of the organic light-emitting diode display described in Item 10 of the patent scope of 18, L5, wherein the second, the optimizing means the organic light-emitting diode The voltage drive of the stereo display produces 裎 μ Γ pixels, which can achieve the lowest current error and high uniformity.