Auto-darkening filter (adf) and control method thereof

A control method of an auto-darkening filter (ADF), wherein the ADF comprises two positive liquid crystal sheets, a control device configured to output an original liquid crystal control signal and a modulatable driving voltage, and a liquid crystal control circuit configured to control the two positive liquid crystal sheets according to the original liquid crystal control signal received, the liquid crystal control circuit comprises a liquid crystal signal control circuit and a liquid crystal driving multiplexing circuit, and the control method comprises the following steps:

• an operating mode generating step:
• enabling, by the control device, a liquid crystal signal control mode 1 to output a control signal of an operating mode 1 and the original liquid crystal control signal when the ADF is in an operating mode and any shading number in a shading number range corresponding to the operating mode 1 is scheduled to be used, or enabling, by the control device, a liquid crystal signal control mode 2 to output a control signal of an operating mode 2 and the original liquid crystal control signal when the ADF is in an operating mode and any shading number in a shading number range corresponding to the operating mode 2 is scheduled to be used;
• a liquid crystal control signal generating step:
• generating, by the liquid crystal signal control circuit, a low-voltage high-frequency liquid crystal control signal and a first control voltage according to the control signal of the operating mode 1 output by the control device, or generating, by the liquid crystal signal control circuit, a high-voltage low-frequency liquid crystal control signal and a second control voltage according to the control signal of the operating mode 2 output by the control device;
• a liquid crystal driving signal generating step:
• receiving, by the liquid crystal driving multiplexing circuit, the low-voltage high-frequency liquid crystal control signal and the first control voltage or the high-voltage low-frequency liquid crystal control signal and the second control voltage output by the liquid crystal signal control circuit and the modulatable driving voltage output by the control device, and generating a low-voltage high-frequency liquid crystal driving signal corresponding to the operating mode 1 or a high-voltage low-frequency liquid crystal driving signal corresponding to the operating mode 2, and outputting same to the two positive liquid crystal sheets;
• and
• a liquid crystal driving step:
• receiving, by the two positive liquid crystal sheets, the low-voltage high-frequency liquid crystal driving signal output by the liquid crystal driving multiplexing circuit, and being in the shading number that is in the shading number range corresponding to the operating mode 1 and is scheduled to be used, or receiving, by the two positive liquid crystal sheets, the high-voltage low-frequency liquid crystal driving signal output by the liquid crystal driving multiplexing circuit, and being the shading number that is in the shading number range corresponding to the operating mode 2 and is scheduled to be used.

The control method according to claim wherein the low-voltage high-frequency liquid crystal control signal is a square wave with an operating voltage range of 4.5-5.5v and a frequency range of 10 Hz to 60 Hz, and the first control voltage is in a range of 4.5-5.5v;

• and the high-voltage low-frequency liquid crystal control signal is a square wave or direct current voltage with an operating voltage range of 6-20v and a frequency range of 0.05 Hz to 20 Hz, and the second control voltage is in a range of 6-20v;
• or
• the low-voltage high-frequency liquid crystal driving signal is a square wave with an operating voltage range of 1.2-5v and a frequency range of 10 Hz to 60 Hz;
• and the high-voltage low-frequency liquid crystal driving signal is a square wave or direct current voltage with an operating voltage range of 6-20v and a frequency range of 0.05 Hz to 20 Hz.