Liquid crystal handwriting panel, handwriting device, and method for controlling same

Patent metadata

Field	Value
Publication number	US-12229373-B2
Application number	US-202117921328-A
Country	US
Kind code	B2
Filing date	Oct 28, 2021
Priority date	Oct 28, 2021
Publication date	Feb 18, 2025
Grant date	Feb 18, 2025

Abstract

Provided is a liquid crystal handwriting panel. The liquid crystal handwriting panel includes: a first substrate and a second substrate that are opposite to each other, and a liquid crystal layer between the first substrate and the second substrate; wherein the first substrate includes: a first base substrate, a touch electrode layer on a side of the first base substrate, and a first drive electrode layer on a side of the first base substrate; the second substrate includes: a second base substrate, a second drive electrode layer on a side of the second base substrate, and a shielding layer on a side of the second base substrate.

First claim

What is claimed is:

1. A liquid crystal handwriting panel, comprising: a first substrate and a second substrate that are opposite to each other, and a liquid crystal layer between the first substrate and the second substrate; wherein
the first substrate comprises: a first base substrate, a touch electrode layer on a side of the first base substrate, and a first drive electrode layer on a side of the first base substrate, wherein the first drive electrode layer is closer to the liquid crystal layer than the touch electrode layer to the liquid crystal layer; and
the second substrate comprises: a second base substrate, a second drive electrode layer on a side of the second base substrate, and a shielding layer on a side of the second base substrate;
wherein the first drive electrode layer comprises a plurality of pixel electrodes, and the second drive electrode layer comprises a common electrode,
wherein the touch electrode layer comprises: a plurality of touch electrode blocks, wherein an orthogonal projection of each of the plurality of touch electrode blocks on the first base substrate is overlapped with an orthogonal projection of at least one of the plurality of pixel electrodes on the first base substrate; and
the first substrate further comprises: a plurality of touch signal lines, wherein the plurality of touch signal lines are electrically connected to the plurality of touch electrode blocks in one-to-one correspondence,
wherein the first substrate further comprises: a second insulation layer between the first drive electrode layer and the touch electrode layer, wherein the touch electrode layer is closer to the first base substrate than the first drive electrode layer to the first base substrate, and
wherein the liquid crystal layer is a bistable liquid crystal molecule layer.

2. The liquid crystal handwriting panel according to claim 1 , wherein in a case that the first drive electrode layer comprises the plurality of pixel electrodes, the first substrate further comprises: a plurality of data lines and a plurality of thin-film transistors, wherein the plurality of data lines are electrically connected to the plurality of pixel electrodes by the plurality of thin-film transistors, and the plurality of data lines and the plurality of touch signal lines are disposed on a same layer and made of a same material.

3. The liquid crystal handwriting panel according to claim 1 , wherein the first substrate further comprises: a first insulation layer between the plurality of touch signal lines and the touch electrode layer, wherein the first insulation layer is provided with a plurality of first vias, and the plurality of touch signal lines are electrically connected to the plurality of touch electrode blocks by at least one of the plurality of first vias.

4. The liquid crystal handwriting panel according to claim 1 , further comprising: a spacer between the first substrate and the second substrate, wherein the spacer is fixed on one of the first substrate and the second substrate.

5. The liquid crystal handwriting panel according to claim 1 , wherein the first base substrate is a flexible base substrate, and both the touch electrode layer and the first drive electrode layer are disposed on a side, close to the second substrate, of the flexible base substrate.

6. A handwriting device, comprising: a liquid crystal handwriting panel, and a control assembly electrically connected to the liquid crystal handwriting panel; wherein
the liquid crystal handwriting panel comprises: a first substrate and a second substrate that are opposite to each other, and a liquid crystal layer between the first substrate and the second substrate; wherein
the first substrate comprises: a first base substrate, a touch electrode layer on a side of the first base substrate, and a first drive electrode layer on a side of the first base substrate, wherein the first drive electrode layer is closer to the liquid crystal layer than the touch electrode layer to the liquid crystal layer; and
the second substrate comprises: a second base substrate, a second drive electrode layer on a side of the second base substrate, and a shielding layer on a side of the second base substrate;
wherein the first drive electrode layer comprises a plurality of pixel electrodes, and the second drive electrode layer comprises a common electrode;

and the control assembly is configured to: determine, in response to the liquid crystal handwriting panel being in an erasing mode, position information of a region to be erased by the touch electrode layer, and apply a pixel voltage to a pixel electrode in the region to be erased, such that a voltage difference is present between the pixel electrode and the common electrode in the region to be erased,
wherein the touch electrode layer comprises: a plurality of touch electrode blocks, wherein an orthogonal projection of each of the plurality of touch electrode blocks on the first base substrate is overlapped with an orthogonal projection of at least one of the plurality of pixel electrodes on the first base substrate; and
the first substrate further comprises: a plurality of touch signal lines, wherein the plurality of touch signal lines are electrically connected to the plurality of touch electrode blocks in one-to-one correspondence,
wherein the first substrate further comprises: a second insulation layer between the first drive electrode layer and the touch electrode layer, wherein the touch electrode layer is closer to the first base substrate than the first drive electrode layer to the first base substrate, and
wherein the liquid crystal layer is a bistable liquid crystal molecule layer.

7. The handwriting device according to claim 6 , wherein the control assembly is further configured to: determine, in response to the liquid crystal handwriting panel being in a writing mode, position information of handwriting by the touch electrode layer, and generate image information corresponding to the handwriting.

8. The handwriting device according to claim 7 , wherein a duration of applying the pixel voltage to the pixel electrode by the control assembly ranges from 150 ms to 650 ms, and a period of sensing a touch position via the touch electrode layer by the control assembly ranges from 2 ms to 40 ms.

9. A method for controlling a handwriting device, applicable to the handwriting device as defined in claim 6 , the method comprising:
determining, in response to the liquid crystal handwriting panel being in an erasing mode, position information of a region to be erased by the touch electrode layer; and
applying, based on the position information of the region to be erased, a pixel voltage to a pixel electrode in the region to be erased by the control assembly, such that a voltage difference is present between the pixel electrode and the common electrode in the region to be erased.

10. The method according to claim 9 , further comprising:
determining, in response to the liquid crystal handwriting panel being in a writing mode, position information of handwriting by the touch electrode layer, and generating image information corresponding to the handwriting.

11. The method according to claim 10 , further comprising:
determining a mode of the liquid crystal handwriting panel by detecting an external object in contact with the first substrate by the touch electrode layer;
determining, in response to the liquid crystal handwriting panel being in the erasing mode, position information of the external object in contact with the first substrate as the position information of the region to be erased; and
determining, in response to the liquid crystal handwriting panel being in the writing mode, position infor

Assignees

• Beijing Boe Optoelectronics Tech Co Ltd
• Boe Technology Group Co Ltd

Inventors

• Wu Xiaojuan
• Wang Xiuliang
• Wang Jian
• Zhao Yu
• Ge Yang
• Wang Jiaxing
• Bi Yao
• Duan Jinshuai
• Yuan Hongliang
• Han Tianyang

Classifications

• G06T11/23

  using straight lines or curves · CPC title

• G09G2300/0486

  Cholesteric liquid crystals, including chiral-nematic liquid crystals, with transitions between focal conic, planar, and homeotropic states · CPC title

• G09G3/3648

  using an active matrix (G09G3/367 - G09G3/3696 take precedence) · CPC title

• G06F3/0412

  Digitisers structurally integrated in a display · CPC title

• G02F1/13338

  Input devices, e.g. touch panels · CPC title