Handwriting board and control method thereof

A control method of a handwriting board, wherein the handwriting board comprises:

• a touch structure, configured to sense the handwriting touch position;
• a filter display structure, comprising a photonic crystal layer and a filter driving circuit, the photonic crystal layer comprises a periodic defect structure of the surface and a photo-dielectric filled in the periodic defect structure, and the filter driving circuit is configured to apply voltage to the photonic crystal layer, so as to change a state of the photo-dielectric in the defect structure;
• and
• a controller, configured to control the filter driving circuit to change a state of the photo-dielectric in the photonic crystal layer in a corresponding region based on the handwriting touch position so as to change forbidden bands of the photonic crystal layer in the corresponding region,
• and the control method comprises:
• acquiring the handwriting touch position;
• and
• generating a control signal corresponding to the handwriting touch position, based on the control signal controlling the filter driving circuit to adjust the voltage value and to change the state of the photo-dielectric of the photonic crystal layer in a region corresponding to the handwriting touch position so as to change the forbidden bands of the photonic crystal layer in the region corresponding to the handwriting touch position.