Liquid crystal handwriting board, handwriting system, and control method for handwriting system

A handwriting system, comprising:

• an erasing tool and a liquid crystal handwriting board;
• wherein
• the liquid crystal handwriting board comprises:
• a liquid crystal panel, a photosensitive assembly, and a control assembly;
• wherein
• the liquid crystal panel comprises a first substrate and a second substrate that are opposite, wherein the first substrate comprises a plurality of pixel regions and a plurality of pixel electrodes in the plurality of pixel regions, and the second substrate comprises a common electrode;
• the photosensitive assembly comprises a plurality of photosensitive elements, wherein one of the plurality of photosensitive elements corresponds to at least one of the plurality of pixel regions, and an orthogonal projection of each of the plurality of photosensitive elements on the first substrate is at least partially overlapped with the corresponding at least one of the plurality of pixel regions;
• and
• the control assembly is electrically connected to the liquid crystal panel and the photosensitive assembly, and is configured to determine position information of a pixel region for erasure by detecting position information of target light irradiated to the liquid crystal panel by the photosensitive assembly and supply a pixel voltage to the plurality of pixel electrodes in the pixel region for erasure, such that a voltage difference is present between the plurality of pixel electrodes in the pixel region for erasure and the common electrode;
• and the erasing tool comprises a light-emitting assembly, and the liquid crystal handwriting board is configured to determine the position information of the pixel region for erasure by detecting the position information of the target light by the photosensitive assembly upon emission of the target light to the liquid crystal panel by the light-emitting assembly of the erasing tool.