Light emitting diode driving method

Abstract

The invention relates to a light emitting diode driving method, suitable for driving a plurality of light emitting diode strings. Each light emitting diode string comprises a light emitting diode or a plurality of light emitting diodes connected in series. The light emitting diode driving method comprises the following steps of: acquiring the initial duty ratio of the driving current of each light emitting diode string in a frequency cycle so as to acquire the target accumulated glow brightness of each light emitting diode string; when the maximum value of the initial duty ratios of the driving currents of the light emitting diode strings in the frequency cycle is smaller than the frequency cycle, extending the duty cycle of the driving current of each light emitting diode string in the frequency cycle and enabling the accumulated brightness of the light emitting diode string in the extended duty cycle to be equal to the target accumulated glow brightness.

Description

technical field [0001] The invention relates to the technical field of driving light emitting diodes, and in particular to a driving method of light emitting diodes. Background technique [0002] For non-self-illuminating displays, for example, the display panel of a liquid crystal display does not emit light itself, so a backlight source is needed to provide backlighting for the display panel. At present, backlight sources can be roughly classified into cold cathode fluorescent lamps, hot cathode fluorescent lamps, light emitting diodes (LEDs) or other electroluminescent elements. Among them, light-emitting diodes are more and more widely used as backlight sources for liquid crystal displays due to their advantages such as high color saturation, no mercury, long life, low energy consumption, and adjustable color temperature through driving current. [0003] see figure 1 and figure 2 ,in figure 1 A structural block diagram of a light-emitting diode backlight module in t...

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Problems solved by technology

[0004] However, for the LED backlight module in the prior art, there will be the following situations: (1) The current value of the driving current of the LED is fixed at the highest gray scale current, and if the highest gray scale current is used when the brightness is not the highest gray scale, it will Make the LEDs operate in the lower luminous efficiency range. (2) When the LEDs are in cut-off period, each LED string has a large cross-voltage on the LED driver, which is likely to cause energy loss and temperature rise. (3) The current consumption is too high. Concentrated, prone to power supply voltage ripple (Ripple)

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