A constant current source drive circuit for oled screen

Abstract

The application discloses a constant current source drive circuit for an OLED screen body. This technical solution can distinguish the short-circuit condition of the OLED screen body, and allows the components to have a certain amount of resistance. When the OLED screen body has a pixel point short-circuit fault, since each pixel point is connected with a fuse-type anti-short circuit structure, the OLED screen body The voltage does not change much, and the constant current source detects that the measured voltage value after the allowable element is connected in series with the OLED pixel is greater than the preset voltage value, which can maintain the constant current output state of the constant current source driver chip; when other non-pixel short circuits occur on the OLED screen When there is a fault, the voltage at both ends of the OLED screen is almost zero. Even if there is an allowable component, the constant current source drive chip detects that the measured voltage value after the allowable component is connected in series with the OLED pixel is still lower than the preset value. At this time, the constant current source The driver chip detects the short circuit of the load and stops the output current to avoid other accidents.

Description

technical field [0001] The disclosure specifically relates to a driving circuit for a constant current source of an OLED screen. Background technique [0002] Most of the OLED screen drive circuits in the prior art are driven by a constant current source, which is generally realized by a constant current source drive chip. At present, the constant current source driver chip actually used continues to use the constant current source driver chip specially designed for LED. In view of the fact that the actual control and drive of the LED is relatively simple, there is only a simple short circuit or open circuit. When the chip detects that the circuit has a short circuit or open circuit , the driver chip stops the supply of current. [0003] As for the OLED screen, its structure and light-emitting principle are special, especially the OLED screen with a fuse-type short-circuit prevention structure, such as the structures of Figure 7(a) and Figure 7(b) disclosed in ZL20128000512...

AI Technical Summary

Problems solved by technology

Even so, when a short circuit occurs at a certain pixel point, the constant current driver chip will detect the short circuit fault and stop the current output. Permanent failure, which also brings technical problems to the constant current source drive of the OLED screen, which needs to be solved urgently

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