Pixel compensation circuit for AMOLED (Active Matrix/Organic Light Emitting Diode) displayer

Abstract

The invention provides a pixel compensation circuit. The pixel compensation circuit comprises a first switch, a second switch, a third switch, a fourth switch, a fifth switch, a sixth switch, a first capacitor, a second capacitor and an organic light-emitting diode, wherein a first end of the first switch receives data voltage; a second end of the first switch receives a first switch signal; a second end of the second switch receives the first switch signal; a second end and a third end of the third switch are both connected to first voltage; a first end of the fifth switch receives reference voltage; a second end of the fifth switch receives a third switch signal; a second end of the sixth switch receives the third switch signal; a first end of the second capacitor is connected to a second end of the first capacitor; a second end of the second capacitor receives a second switch signal; a first end of the organic light-emitting diode is connected to a first end of the sixth switch; and a second end of the organic light-emitting diode is connected to second voltage. Compared with the prior art, the pixel compensation circuit has the advantages that the threshold value voltage of the switches is compensated before a lightening period, so that the influence of the threshold vale voltage on OLED (Organic Light Emitting Diode) current is eliminated, and stable current output of an OLED in a pixel can be kept.

Description

technical field [0001] The invention relates to an active matrix organic light emitting diode display, in particular to a pixel compensation circuit of the AMOLED display. Background technique [0002] Organic light emitting diodes (Organic Light Emitting Diode, OLED) can be divided into passive matrix driving (Passive Matrix OLED, PMOLED) and active matrix driving (Active Matrix OLED, AMOLED) according to the driving method. Among them, the PMOLED does not emit light when data is not written, but only emits light during data writing. This driving method is simple in structure, low in cost, and easy to design, and is mainly suitable for small and medium-sized displays. [0003] The biggest difference between AMOLED and PMOLED is that each pixel has a capacitor to store data, so that each pixel can maintain a light-emitting state. Since the power consumption of AMOLED is significantly lower than that of PMOLED, and its driving method is suitable for the development of large...

AI Technical Summary

Problems solved by technology

However, in the driving mechanism of AMOLED display, OLED controls the brightness of light emission based on the magnitude of the current flowing through it, and the electrical parameters of the thin film transistor used for driving will directly affect the display effect of the screen

For example, due to the influence of the manufacturing process, the threshold voltage (threshold voltage) of the thin film transistor in each pixel may drift. At this time, even if the same data voltage is provided to these pixels, the current flowing through the OLED of each pixel will still increase. There are differences, resulting in uneven brightness in AMOLED displays

[0004] In view of this, how to design a pixel compensation circuit for AMOLED displays to effectively improve or eliminate many defects such as uneven brightness and poor display picture quality is a subject to be solved urgently by relevant technical personnel in the industry

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