Digital dimming device and digital dimming method

Abstract

The invention discloses a digital dimming device and a digital dimming method. The digital dimming device is used for controlling a plurality of light emitting component channels. The digital dimming method disclosed by the invention comprises the following steps of: generating a plurality of drive signals to control current on the light emitting component channels; receiving a pulse width modulation input signal with a duty cycle, and conducting phase shifting to the pulse width modulation input signal to generate a plurality of groups of phase-staggered pulse width modulation output signals, wherein the duty cycles of the pulse width modulation output signals are the same as the duty cycle of the pulse width modulation input signal; and enabling or forbidding the corresponding drive signals by using the groups of pulse width modulation output signals.

Description

technical field [0001] The invention relates to a digital dimming device and a dimming method, in particular to a digital dimming device and a dimming method which can ensure uniform distribution of the lighting time of multiple strings of light-emitting elements. Background technique [0002] In circuits controlling light-emitting elements (eg, light-emitting diodes, LEDs), it is often necessary to provide a dimming function. When multiple strings of light-emitting elements need to be controlled, there are two ways to adjust the brightness in the prior art. The first one is as follows: figure 1 , adjust the brightness of all light-emitting element strings with the same dimming control signal. figure 2 , and use different dimming control circuits to adjust the brightness of each light-emitting element string respectively. In detail, in figure 1 In the first prior art shown, the light-emitting element control circuit includes a power stage control circuit 21, which contro...

AI Technical Summary

Problems solved by technology

If the brightness of each string of light-emitting elements is individually controlled, although the light-dark cycle of each string of light-emitting elements can be independent, it cannot ensure that the lighting time of each string of light-emitting elements is evenly distributed.

[0005] In addition, the frequency of the digital dimming signal is in the range of 60-500Hz, but in some applications, it is impossible to supply such a low-frequency signal

[0006] In view of this, the present invention proposes a digital dimming device and dimming method to solve the problem of uniformity of lighting time, and can receive dimming signal input of various frequencies

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