Voltage driving pixel circuit, driving method thereof and display panel

Abstract

The invention discloses a voltage driving pixel circuit which relates to the technical field of organic light emitting display. The voltage driving pixel circuit comprises a driving transistor, a maintain transistor, a switching transistor, a compensation transistor, a storage capacitor and an OLED (Organic Light Emitting Diode) device, wherein the grid electrode of the switching transistor is connected with a grid line, the source electrode of the switching transistor is connected with a data line, and the drain electrode of the switching transistor is connected with one end of the storage capacitor and the source electrode of the maintain transistor; the grid electrode of the maintain transistor is connected with a first control signal line used for controlling the conduction of the maintain transistor, and the drain electrode of the maintain transistor is connected with the grid electrode of the driving transistor; the grid electrode of the compensation transistor is connected with a second control signal line used for controlling the conduction of the compensation transistor, the source electrode of the compensation transistor is connected with the drain electrode of the driving transistor, and the drain electrode of the compensation transistor is connected with the grid electrode of the driving transistor; the source electrode of the driving transistor is connected with the other end of the storage capacitor and the anode of the OLED device; both the drain electrode of the driving transistor and the source electrode of the drive transistor are connected with a first power supply line; and the cathode of the OLED device is connected with a second power supply line. According to the voltage driving pixel circuit, the nonuniformity of the threshold voltage of an N type TFT (Thin Film Transistor) driving tube and the OLED nonuniformity are effectively compensated.

Description

technical field [0001] The present invention relates to the technical field of organic light-emitting display, in particular to a voltage-driven pixel circuit, a driving method thereof, and a display panel. Background technique [0002] As a current-mode light-emitting device, an organic light-emitting display diode (Organic Electroluminesence Display, OLED) has been increasingly used in high-performance displays. Traditional passive matrix organic light emitting display (Passive Matrix OLED) requires a shorter driving time of a single pixel as the display size increases, and thus needs to increase transient current and increase power consumption. At the same time, the application of high current will cause the voltage drop on the ITO line to be too large, and the working voltage of the OLED will be too high, thereby reducing its efficiency. The active matrix organic light-emitting display (Active Matrix OLED, AMOLED) can well solve these problems by inputting OLED current ...

AI Technical Summary

Problems solved by technology

Since the voltage of ARVDD is related to the current, IR Drop will also cause the current difference in different areas, and then produce moiré in the display

The LTPS process using P-Type TFT to build pixel units is particularly sensitive to this problem, because its storage capacitor is connected between ARVDD and the gate of the TFT, and the voltage change of ARVDD will directly affect the Vgs driving the TFT.

[0006] Third, the uneven film thickness of OLED devices will also cause non-uniformity in electrical properties during evaporation.

[0012] As in the structure in reference [1], such as figure 2 As shown, this structure can only compensate the Vth non-uniformity and drift of the driving tube T4, but cannot compensate OLED non-uniformity

[0013] As in the structure in reference [2], such as image 3 As shown, this structure can compensate the Vth non-uniformity, drift and OLED non-uniformity of the driving tube T1, but it needs 6 TFTs and 1 capacitor, and the structure is complex

[0014] As in the structure in reference [3], such as Figure 4 As shown, this structure can only compensate the non-uniformity and drift of the driving tube T1, but cannot compensate the non-uniformity of the OLED

[0015] As in the structure in reference [4], such as Figure 5 As shown, this structure can compensate the influence of Vth non-uniformity, drift and OLED non-uniformity, but it needs 5T2C, and it is not easy to realize the design of high aperture ratio

[0016] To sum up, in the design of AMOLED pixel structure, the driving circuit cannot well solve the problems of TFT non-uniformity, IR Drop and OLED non-uniformity

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