Method and system for controlling light erasing voltage of liquid crystal writing device

Abstract

The invention discloses a method and system for controlling the erasing voltage of a liquid crystal writing device, comprising: controlling the voltage difference between the base layer and the conductive layer within a set voltage range lower than the erasing voltage of the liquid crystal; and then controlling All or a set part of the TFTs on the base layer are in a critical state, and partial erasing is realized by irradiating light within a set intensity range. The present invention shortens the time required for the light conduction of the TFT by pre-loading the voltage between the base layer and the liquid crystal layer, thereby increasing the local erasing speed.

Description

technical field [0001] The invention relates to the technical field of liquid crystal writing boards, in particular to a method and system for controlling light erasing voltage of a liquid crystal writing device. Background technique [0002] The working principle of the liquid crystal writing board currently on the market is to use the bistable property of the liquid crystal to display and / or erase the written content on the liquid crystal writing board. Taking cholesteric liquid crystal as an example, the writing pressure track of the writing pen is recorded by changing the liquid crystal state at the tip of the pen by the pressure acting on the liquid crystal writing board, and then the corresponding writing content is displayed; the structure of the cholesteric liquid crystal is changed by applying an electric field, Thereby, the writing track on the liquid crystal writing board disappears to realize erasing. [0003] Patent No. CN112684618B discloses a technical soluti...

AI Technical Summary

Problems solved by technology

[0004] In the above scheme, each TFT position on the base layer is correspondingly provided with a TFT light-transmitting port for receiving light irradiation; figure 1 The relationship curve between the illumination time and the voltage difference between the base layer and the liquid crystal layer, if the TFT light-transmitting opening is small, the luminous flux that shines on the TFT through the opening is small, and the light conduction current is small, and the base layer The voltage change between the liquid crystal layer and the liquid crystal layer is slow, and it takes a long time to illuminate to make the voltage difference between the set erasing electrode and the conductive layer reach the erasing voltage of the liquid crystal, resulting in a longer erasing time and lower writing Erase efficiency, poor user experience

[0005] On the other hand, affected by the doping concentration of the TFT channel, if the doping concentration of the TFT channel is small, the photosensitivity of the TFT will deteriorate, which will also make the photoconduction current too small, thereby affecting the time required for partial erasing.

[0006] When the storage capacitor design on the TFT substrate is large, the voltage changes slowly and the erasing time is very long

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