Patent ID: 12253750

DETAILED DESCRIPTION OF THE INVENTION

For clearer descriptions of the objectives, technical solutions, and advantages of the present disclosure, the embodiments of the present disclosure are described in detail hereinafter with reference to the accompanying drawings.

In some practices, in order to local erasure of the handwriting displayed on the liquid crystal handwriting board, it is necessary to integrate an infrared positioning apparatus in the liquid crystal handwriting board. During erasure of the handwriting by an erasing tool (for example, an eraser), a position of the erasing tool on the liquid crystal handwriting board is determined by the infrared positioning apparatus to determine a region for erasure on the liquid crystal handwriting board. Afterwards, the liquid crystal handwriting board controls pixel electrodes in the region for erasure to erase the handwriting in the region for erasure. Referring toFIG.1andFIG.2,FIG.1is a top view of a liquid crystal handwriting board according to some practices, andFIG.2is a cross-sectional view of the liquid crystal handwriting board shown inFIG.1at A-A′. The liquid crystal handwriting board00generally includes: a liquid crystal panel01, a black aluminum honeycomb panel02, and an infrared positioning apparatus03.

The liquid crystal panel01includes: a first substrate011and a second substrate012that are opposite, and a liquid crystal layer013disposed between the first substrate011and the second substrate012. The first substrate011is generally provided with a plurality of pixel electrodes (not shown in drawings) arranged in an array, and the second substrate012is provided with a planar common electrode (not shown in drawings). Liquid crystal molecules in the liquid crystal layer013are bistable liquid crystal molecules.

The black aluminum honeycomb panel02is disposed on a side, distal from the second substrate012, of the first substrate011. The infrared positioning apparatus03is disposed on a periphery of the liquid crystal panel01and the black aluminum honeycomb panel02. The infrared positioning apparatus03requires to be protruded from the liquid crystal panel01and can emit infrared rays, such that a position of an erasing tool on the liquid crystal panel01is determined.

As shown inFIG.3,FIG.3is a schematic diagram of a principle of displaying handwriting on the liquid crystal handwriting board shown inFIG.1. In the case that the liquid crystal handwriting board00is in a writing mode, a writing tool001(for example, a handwriting pen) supplied a pressure on the liquid crystal panel01, such that a part of liquid crystal molecules in the liquid crystal layer013of the liquid crystal panel01are transformed from a focal cone texture to a planar texture under an action of an external pressure. As such, the liquid crystal molecules transformed to the planar texture can reflect light (for example, green light) with a specific wavelength in the incident ambient light, such that the liquid crystal handwriting board displays the handwriting.

In the case that the liquid crystal handwriting board00is in an erasing mode, the erasing tool002moves on the liquid crystal panel01, the liquid crystal handwriting board00determines a position of the erasing tool002on the liquid crystal panel01based on infrared rays emitted by the infrared positioning apparatus03, and then a region for erasure is determined from the liquid crystal handwriting board00. Afterwards, the liquid crystal handwriting board applies a voltage to the pixel electrodes in the region for erasure, such that a voltage difference is present between the pixel electrodes in the region for erasure and the common electrode, and then the liquid crystal molecules in the region for erasure are rearranged under an action of the voltage difference, that is, the liquid crystal molecules are transformed from the planar texture to the focal cone texture. In this way, the liquid crystal molecules transformed to the focal cone texture transmit incident ambient light, such that the region for erasure shows a black background with the same color as the black aluminum honeycomb panel02, and the erasure of the handwriting in the region for erasure is achieved.

The infrared positioning apparatus03in the liquid crystal handwriting board00generally requires to distinguish the writing tool001and the erasing tool002to ensure that the writing tool001normally writes on the liquid crystal handwriting board00and the erasing tool002erases the handwriting displayed on the liquid crystal handwriting board00. Thus, a face, in contact with the liquid crystal handwriting board00, of the erasing tool002requires to be much greater than a face, in contact with the liquid crystal handwriting board00, of the writing tool001, such that the infrared positioning apparatus03distinguishes the writing tool001and the erasing tool002by detecting a contact area of an object and the liquid crystal handwriting board00.

However, a hand of a user tends to in contact with the liquid crystal handwriting board in the case that the user writes on the liquid crystal handwriting board00by the writing tool001, and a contact area of the hand of the user and the liquid crystal handwriting board00is generally great, such that the infrared positioning apparatus03is prone to determining that the hand of the user is the erasing tool002, and handwriting in a contact region of the hand of the user and the liquid crystal handwriting board00is falsely erased. As such, an effect of locally erasing the liquid crystal handwriting board is poor.

Referring toFIG.4,FIG.4is a schematic structural diagram of a liquid crystal handwriting board according to some embodiments of the present disclosure. The liquid crystal handwriting board000includes:a liquid crystal panel100, a photosensitive assembly200, and a control assembly300.

The liquid crystal panel100includes a first substrate101and a second substrate102that are opposite. In the embodiments of the present disclosure, the liquid crystal panel100further includes a liquid crystal layer103between the first substrate101and the second substrate102. In some embodiments, the liquid crystal layer103is a bistable liquid crystal molecule layer, that is, liquid crystal molecules in the liquid crystal layer103are bistable liquid crystal molecules. Illustratively, the bistable liquid crystal molecules are configured to transform from a focal cone texture to a planar texture in the case that an external pressure is supplied on the liquid crystal panel100in the liquid crystal handwriting board000. For example, in the case that the user writes on the liquid crystal handwriting board000by the writing tool, the user supplies a pressure on the liquid crystal panel100by the writing tool, such that the bistable liquid crystal molecules in a region supplied with the pressure in the liquid crystal panel100are transformed from the focal cone texture to the planar texture. In this case, the bistable liquid crystal molecules in the planar texture can reflect light (for example, green light) with a specific wavelength in the incident ambient light irradiated to the liquid crystal panel100, such that the liquid crystal handwriting board000displays the corresponding handwriting.

The first substrate101in the liquid crystal panel100includes a plurality of pixel regions101a(not annotated inFIG.4but annotated inFIG.6) and a pixel electrode1011in the pixel region101a. Illustratively, one pixel electrode1011is disposed in each pixel region101ain the first substrate101, and the pixel electrode1011is a block electrode. The plurality of pixel regions101ain the first substrate101are arranged in an array, and thus a plurality of pixel electrodes1011in the first substrate101are also arranged in an array. It should be noted that the first substrate101further includes a plurality of data signal lines and a plurality of gate lines (that is, the following first gate line G1), any two adjacent data signal lines and any two adjacent gate liens enclose one pixel region101a, and one pixel electrode1011in the first substrate101is disposed in one pixel region101a.

The second substrate102in the liquid crystal panel100includes a common electrode1021. Illustratively, the common electrode1021in the second substrate102is a planar electrode, that is, the common electrode1021is a whole-layer electrode.

The photosensitive assembly200includes a plurality of photosensitive elements201. One photosensitive element201corresponds to at least one pixel region101ain the first substrate101, and an orthogonal projection of each photosensitive element201in the photosensitive assembly200on the first substrate101is at least partially overlapped with the corresponding at least one pixel region101a. In the present disclosure, each photosensitive element201in the photosensitive assembly200corresponds to at least one pixel region101a.

The control assembly300is electrically connected to the liquid crystal panel100and the photosensitive assembly200. Illustratively, the control assembly300is electrically connected to the liquid crystal panel100and the pixel electrodes1011, and the control assembly300is further electrically connected to the photosensitive elements201in the photosensitive assembly200.

The control assembly300is configured to determine position information of a pixel region for erasure by detecting position information of target light irradiated to the liquid crystal panel100by the photosensitive assembly200and supply a pixel voltage to the pixel electrodes1011in the pixel region for erasure, such that a voltage difference is present between the pixel electrodes1011in the pixel region for erasure and the common electrode1021.

In the embodiments of the present disclosure, in the case that the handwriting displayed on the liquid crystal handwriting board000requires to be erased, an erasing tool capable of emitting the target light is used to erase the handwriting. As the orthogonal projection of the photosensitive element201in the photosensitive assembly200on the first substrate101is at least partially overlapped with the corresponding at least one pixel region101a, at least a part of photosensitive elements201in the photosensitive assembly200senses the target light emitted from the erasing tool and passing through the liquid crystal panel100upon emission of the target light from the erasing tool to the liquid crystal panel100, and the position of the target light irradiated to the liquid crystal panel100is determined by the control assembly300. The position of the light irradiated to the liquid crystal panel100is a position of the pixel region for erasure.

In some embodiments, the plurality of photosensitive elements201in the photosensitive assembly200are arranged in an array, and thus the control assembly300can determine the position information of a photosensitive element in the plurality of photosensitive elements201upon sensing the target light emitted from the erasing tool by the photosensitive element in the photosensitive assembly200. Then, the control assembly300determines the position information of the target light irradiated to the liquid crystal panel100based on the position information of the photosensitive element in the plurality of photosensitive elements and the corresponding relationship of the photosensitive elements201and the pixel regions101a, such that the position information of the pixel region for erasure is acquired.

As such, the liquid crystal handwriting board detects the position information of the pixel region for erasure by the photosensitive assembly200, and then supplies the pixel voltage to the pixel electrodes1011in the pixel region for erasure by the control assembly300, such that the voltage difference is present between the pixel electrodes1011in the pixel region for erasure and the common electrode1021. Illustratively, the bistable liquid crystal molecules are further configured to transform form the planar texture to the focal cone texture in the case that the voltage difference is present between the pixel electrodes1011in the pixel region for erasure and the common electrode1021. For example, in the case that the user erases the liquid crystal handwriting board000by the erasing tool capable of emitting the target light, the user emits the target light to the liquid crystal panel100by the erasing tool, such that the control assembly300determines the pixel region for erasure and supplies the pixel voltage to the pixel electrodes1011in the pixel region for erasure, and the voltage difference is present between the pixel electrodes1011in the pixel region for erasure and the common electrode1021. Furthermore, the bistable liquid crystal molecules in the pixel region for erasure in the liquid crystal handwriting board000are transformed from the planar texture to the focal cone texture. As such, the bistable liquid crystal molecules in the focal cone texture transmit the ambient light irradiated to the liquid crystal panel100, such that the erasure of the handwriting in the pixel region for erasure is achieved.

In summary, the liquid crystal handwriting board in the embodiments of the present disclosure includes: a liquid crystal panel, a photosensitive assembly, and a control assembly. In the case that handwriting displayed on the liquid crystal handwriting board requires to be erased, an erasing tool capable of emitting target light erases the handwriting. As an orthogonal projection of a photosensitive element in the photosensitive assembly on a first substrate of the liquid crystal panel is at least partially overlapped with the corresponding pixel region, the photosensitive assembly determines a position of target light irradiated to the liquid crystal panel by detecting the target light by at least a part of photosensitive elements upon emission of the target light to the liquid crystal panel by the erasing tool, and the position of target light irradiated to the liquid crystal panel is a position of a pixel region for erasure. As such, the liquid crystal handwriting board supplies a pixel voltage to pixel electrodes in the pixel region for erasure by the control assembly, such that the erasure of the handwriting in the pixel region for erasure is achieved. In this case, even if a hand of a user is in contact with the liquid crystal handwriting board in writing, the photosensitive assembly does not determine a region in which the user is in contact with the liquid crystal handwriting board as the pixel region for erasure, such that a possibility of false erasure in the liquid crystal handwriting board is reduced, and an effect of locally erasing the liquid crystal handwriting board is efficiently improved.

It should be noted that a light intensity of the target light requires to be much greater than a light intensity of the ambient light to ensure that the photosensitive assembly200distinguishes the target light and the ambient light. As the photosensitive assembly200is generally disposed on a side, distal from the second substrate102, of the liquid crystal layer103in the liquid crystal panel100, the target light generally requires to pass through the liquid crystal layer103and irradiate to the photosensitive assembly200. In the case that the bistable liquid crystal molecules in the liquid crystal handwriting board000are in the planar texture, the bistable liquid crystal molecules reflect the green light. Thus, the target light requires to be light of colors other than the green light to ensure that the target light normally passes through the bistable liquid crystal molecules in the planar texture. For example, the target light is a white light, a red light, a blue light, and the like.

In the embodiments of the present disclosure, the photosensitive assembly200in the liquid crystal handwriting board000are of many structures, and the embodiments of the present disclosure are illustrated in the following two optional implementations.

In a first optional implementation, referring toFIG.5,FIG.5is a schematic structural diagram of another liquid crystal handwriting board according to some embodiments of the present disclosure. The photosensitive assembly200in the liquid crystal handwriting board000is disposed on a side, distal from the second substrate102, of the first substrate101. Illustratively, the photosensitive assembly200includes a circuit board202and the plurality of photosensitive elements201on the circuit board202. The plurality of photosensitive elements201in the photosensitive assembly200are all electrically connected to the circuit board202, and the circuit board202is electrically connected to the control assembly300. The control assembly300monitors parameters of the photosensitive elements201by the circuit board202. In some embodiments, the photosensitive elements201in the photosensitive assembly200are all photosensitive resistors, photosensitive diodes, photosensitive transistors, or the like.

In this case, the photosensitive assembly200is attached to the side, distal from the second substrate102, of the first substrate101, and the plurality of photosensitive elements201in the photosensitive assembly200face towards the first substrate101, such that the target light passing through the liquid crystal panel100is irradiated to the photosensitive element201. Upon receiving of the target light by the photosensitive element201, parameters (for example, a resistance) of the photosensitive element201are changed. As such, the control assembly300determines the position of the photosensitive element201with the changed parameters in the photosensitive assembly200by the circuit board202, and the position information of the target light irradiated to the liquid crystal panel100is further determined. It should be noted that the circuit board202in the photosensitive assembly200is a printed circuit board (PCB) or a flexible printed circuit (FPC).

In some embodiments, the plurality of photosensitive elements201in the photosensitive assembly200are connected to the circuit board202through a surface mounted technology (SMT). For example, a plurality of solder pastes are printed on the circuit board202, and the plurality of photosensitive elements201are transferred to the circuit board202, such that the plurality of photosensitive elements201are in contact with the plurality of solder pastes in one-to-one correspondence. Then, a reflow soldering is performed on the circuit board, such that each of the plurality of photosensitive elements201is electrically connected to the circuit board202by the corresponding solder paste. Eventually, an optical detection is performed on the circuit board202including the plurality of photosensitive elements201by an automatic optic inspection (AOI).

In the embodiments of the present disclosure, the liquid crystal handwriting board000further includes a black matrix400. The black matrix400in the liquid crystal handwriting board000is disposed between the plurality of pixel electrodes1011on the first substrate101and the plurality of photosensitive elements201in the photosensitive assembly200.

As shown inFIG.6,FIG.7, andFIG.8,FIG.6is a top view of a first substrate, a black matrix, and a photosensitive assembly that are laminated according to some embodiments of the present disclosure,FIG.7is a top view of the black matrix in the structure shown inFIG.6, andFIG.8is a top view of the photosensitive assembly in the structure shown inFIG.6. A plurality of light apertures401are defined in the black matrix400in the liquid crystal handwriting board000. The plurality of light apertures401in the black matrix400are in one-to-one correspondence to the plurality of pixel regions101ain the first substrate101, and an orthogonal projection of each of the plurality of light apertures401on the first substrate101is within the corresponding pixel region101a. As each of the plurality of photosensitive elements201in the photosensitive assembly200corresponds to at least pixel region101a, at least one of the plurality of light apertures401in the black matrix400corresponds to one of the plurality of photosensitive elements201in the photosensitive assembly200, and the orthogonal projection of each of the plurality of light apertures401on the first substrate101is at least partially overlapped with an orthogonal projection of the corresponding photosensitive element201on the first substrate101.

In this case, the target light irradiated to the pixel regions101ain the first substrate101in the liquid crystal panel100sequentially passes through the corresponding light apertures and is irradiated to the corresponding photosensitive element201in the photosensitive assembly200, such that the photosensitive assembly200senses the target light irradiated to any pixel region101aby the plurality of photosensitive elements201.

It should be noted thatFIG.6is illustrated by taking the light apertures401in the black matrix400being in square shapes as an example. In some embodiments, the light apertures401in the black matrix400are in circular, rectangular, or other shapes, which is not limited in the embodiments of the present disclosure.

In some embodiments, as a width of the handwriting in writing on the liquid crystal handwriting board by the writing tool by the user is great, and a width of the pixel region101ais less, each photosensitive element201in the photosensitive assembly200requires to correspond to a plurality of pixel regions101ato improve an efficiency of erasing the handwriting. For example, each photosensitive element201corresponds to four pixel regions101a, the four pixel regions101aare arranged in two rows and two columns, and orthogonal projections of four pixel electrodes1011arranged in the four pixel regions101aon the photosensitive assembly200are within regions of the corresponding photosensitive elements201.

In this case, the four pixel regions101aform a minimum erasing region. In the case that any pixel region101ain the four pixel regions101areceives irradiation of the target light, the corresponding photosensitive element201is detected, such that the handwriting displayed on the minimum erasing region formed by the four pixel regions101ais erased.

In some embodiments, an area of the orthogonal projection of the light aperture401in the black matrix400on the first substrate101is not less to ensure that the target light normally passes through the light aperture401and is irradiated to the photosensitive element201. The area of the orthogonal projection of the light aperture401in the black matrix400on the first substrate101is not great to ensure that the target light passes through the liquid crystal layer103and is absorbed by the black matrix400in the case that the bistable liquid crystal molecules in the liquid crystal handwriting board000are in the focal cone texture, such that the black background is displayed. Illustratively, a proportion of the area of the orthogonal projection of the light aperture401in the black matrix400on the first substrate101based on an area of the corresponding pixel region101aranges from 5% to 20%. For example, assuming that a size of the pixel region101ain the first substrate101is 1 mm*1 mm, and the proportion of the area of the orthogonal projection of the light aperture401on the first substrate101based on the area of the corresponding pixel region101ais 10%, a size of the light aperture401is 0.1 mm*0.1 mm.

In the embodiments of the present disclosure, in a target direction, in at least two light apertures401corresponding to at least two adjacent pixel regions101a, an arrangement direction of any two adjacent light apertures401is intersected with the target direction. For example, the arrangement direction of two light apertures401corresponding to any two adjacent pixel regions101ais intersected with the target direction. The target direction is an arrangement direction of one row of pixel regions101a. The arrangement direction of the one row of pixel regions101ais a row arrangement direction of the pixel regions101a, a column arrangement direction of the pixel regions101a, or an oblique arrangement direction of the pixel regions101a. As such, the plurality light apertures401in the black matrix400are chaotically arranged, such that bright lines in a back face of the liquid crystal panel100due to light leakage in the case that the light apertures401in the black matrix400are arranged in one row or one column are avoided.

In some embodiments, the plurality of light apertures401in the black matrix400include at least one set of light apertures. Positions of orthogonal projections of the light apertures401in each of the at least one set of light apertures on the first substrate101in the corresponding pixel region101aare different. In some embodiments of the present disclosure, in the case that the plurality of light apertures401in the black matrix400are organized to a plurality of sets of light apertures, the arrangements of the light apertures401in the plurality of sets of light apertures are the same. For example, 36 light apertures401corresponding to each 36 pixel regions101aform one set of light apertures, and the 36 pixel regions101aare arranged in six rows and six columns. The positions of the orthogonal projections of the light apertures401in each set of light apertures on the first substrate101in the corresponding pixel region101aare different. The difficulty of manufacturing the black matrix400is efficiently reduced by organizing the plurality of light apertures401.

In some embodiments, referring toFIG.9andFIG.10,FIG.9is a top view of a first substrate according to some embodiments of the present disclosure, andFIG.10is a schematic structural diagram of film layers of the first substrate shown inFIG.9at B-B′. The first substrate101in the liquid crystal panel100includes a first base substrate1012, and the plurality of pixel electrodes1011and a plurality of driving thin-film transistors (TFTs)1013that are disposed on the first base substrate1012. The plurality of pixel electrodes1011in the first substrate101are electrically connected to the plurality of driving TFTs1013in one-to-one correspondence.

In the embodiments of the present disclosure, there are many positions of the black matrix400in the liquid crystal handwriting board000, and the embodiments of the present disclosure are illustrated in the implementation corresponding to the following two cases.

In a first case, as shown inFIG.10, the black matrix400in the liquid crystal handwriting board000is disposed on a side, facing away from the second substrate102, of the first base substrate1012in the first substrate101.

In a second case, as shown inFIG.11,FIG.11is a schematic structural diagram of another film layers of the first substrate shown inFIG.9at B-B′. The black matrix400in the liquid crystal handwriting board000is disposed on a side, facing towards the second substrate102, of the first base substrate1012in the first substrate101. In this case, as the black matrix400is conductive, a first insulative layer1014is disposed between the black matrix400and the plurality of driving TFTs1013to avoid the short circuit in the driving TFTs1013on the first base substrate1012. Illustratively, the first insulative layer1014is a transparent insulative layer, such that the black matrix400is insulated from the driving TFT1013on the premise that the irradiation of the target line to the photosensitive assembly200through the light apertures401in the black matrix400is not affected.

In some embodiments of the present disclosure, the black matrix400in the above two cases is formed on the first base substrate1012by a screen printing process or a patterning process.

In the case that the black matrix400is formed on the first base substrate1012by the screen printing process, a layer of black ink is printed on the first base substrate1012by a screen printing device and is dried to acquire the black matrix400.

In the case that the black matrix400is formed on the first base substrate1012by the patterning process, a black thin film is formed on the first base substrate1012by depositing, coating, sputtering, or the like, and is exposed and developed to acquire the black matrix400.

In the embodiments of the present disclosure, as the black aluminum honeycomb panel in the liquid crystal handwriting board is replaced with the black matrix400in the liquid crystal handwriting board000, and a thickness of the black matrix400is less than a thickness of the black aluminum honeycomb panel, a thickness and a weight of the liquid crystal handwriting board000in the embodiments of the present disclosure are less.

It should be noted that the black matrix400in the liquid crystal handwriting board000can be integrated in the first substrate101or the photosensitive assembly200. Illustratively, as shown inFIG.12,FIG.12is a schematic structural diagram of film layers of a photosensitive assembly according to some embodiments of the present disclosure. The photosensitive assembly200further includes a planarization layer203on a side, distal from the circuit board202, of the plurality of photosensitive elements201, and the black matrix400in the liquid crystal handwriting board000is disposed on a side, distal from the circuit board202, of the planarization layer203. The planarization layer203is a transparent insulative layer, such that the planarization layer203improves a flatness of a side, facing towards the first substrate101, of the photosensitive assembly, the flatness of the black matrix400is great, and the black matrix400is insulated from the photosensitive elements201on the premise that the irradiation of the target line to the photosensitive assembly200through the light apertures401in the black matrix400is not affected.

In some embodiments, as shown inFIG.10andFIG.11, the driving TFT1013in the first substrate101includes a gate1013a, a first electrode1013b, a second electrode1013c, and an active layer1013d. In the driving TFT1013, the first electrode1013band the second electrode1013care in lap with the active layer1013d, and the active layer1013dis insulated from the gate1013a. For example, the active layer1013dis insulated from the gate1013aby a gate insulative layer1015. It should be noted that the embodiments of the present disclosure are illustrated by taking the gate1013ain the driving TFT1013being closer to the first base substrate1012than the active layer1013das an example. That is, the driving TFT1013is a bottom-gate TFT. In some embodiments, the driving TFT1013is a top-gate TFT, which is not limited in the embodiments of the present disclosure. It should be noted that the first electrode1013bof the driving TFT1013is one of a source and a drain, and the second electrode1013cis the other of the source and the drain.

In the embodiments of the present disclosure, as shown inFIG.10andFIG.11, the first substrate101further includes a second insulative layer1016between the driving TFT1013and the pixel electrode1011. The pixel electrode1011is disposed on the second insulative layer1016, and the second insulative layer1016protects the driving TFT1013and improves the flatness of the pixel electrode1011. In this case, a first via V1is defined in the second insulative layer1016, and the pixel electrode1011is electrically connected to the second electrode1013cof the driving TFT through the first via V1.

The first substrate101further includes a third second insulative layer1017on a side, distal from the first base substrate1012, of the pixel electrode1011. In the case that the first substrate101is opposite to the second substrate102, as a device environment is not a dust-free environment, foreign matter is present between the first substrate101and the second substrate102. Thus, the third second insulative layer1017can avoid the foreign matter between the first substrate101and the second substrate102and conduct the pixel electrode1011in the first substrate101and the common electrode1021in the second substrate102.

As shown inFIG.9, the first substrate101further includes a first gate line G1electrically connected to the gate1013aof the driving TFT1013and a data signal line D1electrically connected to the first electrode1013bof the driving TFT1013. Generally, a plurality of first gate lines G1are defined, and the plurality of first gate lines G1are parallel. A plurality of data signal lines D1are defined, and the plurality of data signal lines D1are parallel. An extension direction of the first gate line G1is perpendicular to an extension direction of the data signal line D1, such that any two adjacent first gate lines G1and any two adjacent data signal line D1enclose a rectangular pixel region101a.

In the embodiments of the present disclosure, the first gate line G1and the data signal line D1in the first substrate101are electrically connected to the control assembly300, such that the control assembly300supplies the pixel voltage to the pixel electrode1011through the first gate line G1and the data signal line D1.

In a second optional implementation, referring toFIG.13,FIG.13is a schematic structural diagram of another liquid crystal handwriting board according to some embodiments of the present disclosure. The photosensitive assembly200in the liquid crystal handwriting board000is integrated in the first substrate101, such that the thickness of the liquid crystal handwriting board000is less without attaching the liquid crystal panel100in the liquid crystal handwriting board000to the photosensitive element including the circuit board.

In the embodiments of the present disclosure, the liquid crystal handwriting board000further includes a back film layer500. The back film layer500is disposed on a side, distal from the second substrate102, of the liquid crystal layer103in the liquid crystal panel100. As such, the target light passes through the liquid crystal layer103and is absorbed by the black film layer500in the case that the bistable liquid crystal molecules in the liquid crystal handwriting board000are in the focal cone texture, such that the black background is displayed. It should be noted that the black film layer500and the black matrix400in the first optional implementation differ in that the light aperture is not required to be disposed in the black film layer500. Thus, the position and forming manner of the black film layer500can be referred to the position and forming manner of the black matrix400in the first optional implementation, which are not repeated in the embodiments of the present disclosure.

As shown inFIG.14,FIG.14is a top view of a first substrate and a black film layer that are laminated according to some embodiments of the present disclosure. As the first substrate101is generally a substrate integrated with a plurality of driving TFTs1013arranged in the array, the photosensitive element201is determined as a photosensitive TFT capable of detecting the target light to ensure that the photosensitive assembly200is integrated in the first substrate101. That is, the photosensitive elements201in the photosensitive assembly200are the photosensitive TFTs201′.

In the embodiments of the present disclosure, a plurality of photosensitive TFTs201′ in the first substrate101are in one-to-one correspondence to the plurality of pixel regions101a, and each photosensitive TFT201′ is within the corresponding pixel region101a.

In this case, the target light irradiated to the pixel regions101ain the first substrate101in the liquid crystal panel100is sensed by the photosensitive TFT201′ in the pixel region101a, such that the photosensitive assembly200senses the target light irradiated to any pixel region101aby the plurality of photosensitive TFTs201′. In addition, in the case that the target light irradiated to the pixel region101ais sensed by a single photosensitive TFTs201′, the light intensity of the target line is not required to be great. As such, the light intensity of the target line is slightly greater than the light intensity of the ambient line, such that the target light irradiated to any pixel region101adoes not affect the normal operation of the driving TFT1013.

In the embodiments of the present disclosure, as shown inFIG.15andFIG.16,FIG.15is a top view of a pixel region in a first substrate according to some embodiments of the present disclosure, andFIG.16is a schematic structural diagram of film layers of the first substrate shown inFIG.15at C-C′. The first substrate101includes a first base substrate1012, and the plurality of pixel electrodes1011and a plurality of driving TFTs1013that are disposed on the first base substrate1012. It should be noted that the connection manner of the pixel electrode1011and the driving TFT1013in the first substrate101and other structures in the first substrate101can be referred to the corresponding description in the first optional implementation, which are not repeated in the embodiments of the present disclosure. For simplification of the manufacturing process of the first substrate101, the driving TFT1013and the photosensitive TFT201′ in the first substrate101are disposed in the same layer. That is, in manufacturing the first substrate101, the driving TFT1013and the photosensitive TFT201′ are formed simultaneously.

Illustratively, the photosensitive TFT201′ includes a gate201a, a first electrode201b, a second electrode201c, and an active layer201d. In the photosensitive TFT201′, the first electrode201band the second electrode201care in lap with the active layer201d, and the active layer201dis insulated from the gate201a. For example, the active layer201dis insulated from the gate201aby a gate insulative layer1015. It should be noted that the first electrode201bof the photosensitive TFT201′ is one of a source and a drain, and the second electrode201cis the other of the source and the drain.

In this case, the gate201aof the photosensitive TFT201′ and the gate1013aof the driving TFT1013are formed by a one patterning process, the first electrode201band the second electrode201cof the photosensitive TFT201′ and the first electrode1013band the second electrode1013cof the driving TFT1013are formed by a one patterning process, and the active layer201dof the photosensitive TFT201′ and the active layer1013dof the driving TFT1013are formed by a one patterning process. It should be noted that the one patterning process in the embodiments of the present disclosure is photoresist coating, exposing, developing, etching, and photoresist removing.

In some embodiments, as shown inFIG.15, the photosensitive assembly200further includes a photosensitive signal line D2electrically connected to the first electrode201bof the photosensitive TFT201′, and a first sensing line L1and a second sensing line L2that are electrically connected to the second electrode201cof the photosensitive TFT201′. The control assembly200in the liquid crystal handwriting board000is electrically connected to the photosensitive signal line D2, the first sensing line L1, and the second sensing line L2, an extension direction of the first sensing line L1is perpendicular to an extension direction of the second sensing line L2, and the extension direction of the first sensing line L1is parallel to an extension direction of the photosensitive signal line D2.

In the embodiments of the present disclosure, a plurality of photosensitive signal lines D2, a plurality of first sensing lines L1, and a plurality of second sensing lines L2are defined in the control assembly200. The plurality of photosensitive TFTs201′ are arranged in an array, each photosensitive signal line D2is electrically connected to the first electrodes201bof one column of photosensitive TFTs201′, each first sensing line L1is electrically connected to the second electrodes201cof one column of photosensitive TFTs201′, and each second sensing line L2is electrically connected to the second electrodes201cof one row of photosensitive TFTs201′. As such, each two first sensing line L1and second sensing line L2that are intersected is electrically connected to the second electrodes201cof the same photosensitive TFT201′ at the intersection position.

In this case, in the case that the photosensitive assembly200is in an operation state, the control assembly simultaneously supplies an electric signal to the photosensitive signal line D2. In the case that no target light is irradiated, the first electrode201band the second electrode201cof the photosensitive TFT201′ are not conducted, such that the electric signal supplied to the photosensitive signal line D2is not transmitted to the first sensing line L1and second sensing line L2. In the case that the target light is irradiated, a number of hole-electron pairs in the active layer201dof the photosensitive TFT201′ is increased, such that a leakage current in the photosensitive TFT201′ is increased, the first electrode201band the second electrode201cof the photosensitive TFT201′ are conducted, and the electric signal supplied to the photosensitive signal line D2is transmitted to the first sensing line L1and second sensing line L2. In addition, the first sensing line L1and second sensing line L2are electrically connected to the control assembly300. As such, the control assembly300can positioning the photosensitive TFT201′ of the sensed target light by sensing a change in a current of the first sensing line L1and a change in a current of the second sensing line L2, such that the position of the target light irradiated to the pixel region101ais further determined.

In some embodiments, the photosensitive assembly200further includes a second gate line G2electrically connected to the gate201aof the photosensitive TFT201′. The second gate line G2is electrically connected to the control assembly300, and an extension direction of the second gate line G2is parallel to the extension direction of the second sensing line L2. In the case that the photosensitive assembly200is in the operation state, the control assembly300supplies a gate voltage to the gate201aof the photosensitive TFT201′ through the second gate line G2, and the gate voltage is less. In the case that no target light is irradiated, the gate voltage supplied to the gate201aof the photosensitive TFT201′ does not control the first electrode201band the second electrode201cof the photosensitive TFT201′ to be conducted. By supplying a less gate voltage to the gate201aof the photosensitive TFT201′ through the second gate line G2, the first electrode201band the second electrode201cof the photosensitive TFT201′ are conducted in the case that the target light is irradiated to the photosensitive TFT201′.

In the embodiments of the present disclosure, for simplification of the manufacturing difficulty of the first substrate101, the data signal line D1, the photosensitive signal line D2, and the first sensing line L1in the first substrate101are disposed in the same layer, that is, a source and drain metal layer including the data signal line D1, the photosensitive signal line D2, and the first sensing line L1is formed by a one patterning process. In addition, the first gate line G1, the second gate line G2, and the second sensing line L2in the first substrate101are disposed in the same layer, that is, a gate metal layer including the first gate line G1, the second gate line G2, and the second sensing line L2is formed in a one patterning process. The source and drain metal layer further includes a first electrode and a second electrode of the TFT integrated in the first substrate101, and the gate metal layer further includes a gate of the TFT integrated in the first substrate101.

In this case, as shown inFIG.16, the photosensitive signal line D2is electrically connected to the first electrode201bof the photosensitive TFT201′, and the first sensing line L1is electrically connected to the second electrode201cof the photosensitive TFT201′. A gate insulative layer1015is disposed between the gate metal layer and the source and drain metal layer in the first substrate101, and a connecting electrode is configured to connect the second sensing line L2and the second electrode201cof the photosensitive TFT201′ to ensure that the second sensing line L2is electrically connected to the second electrode201cof the photosensitive TFT201′.

In some embodiments, the photosensitive assembly200further includes a connecting electrode204in a same layer as the pixel electrode1011, and the connecting electrode204is electrically connected to the second electrode201cof the photosensitive TFT201′ and the second sensing line L2. For example, the second insulative layer1016in the first substrate101includes a second via V2, and a conducted third via V3is defined in the gate insulative layer1015and the second insulative layer1016in the first substrate101. As such, the connecting electrode204is electrically connected to the second electrode201cof the photosensitive TFT201′ through the second via V2, and is electrically connected to the second sensing line L2through the third via V3.

It should be noted that the pixel electrode1011and the connecting electrode204are formed by a one patterning process, and the pixel electrode1011is insulated from the connecting electrode204by a slit d.

In some embodiments, for a less number of lines in the first substrate101, the data signal line D1and the photosensitive signal line D2in the first substrate101are shared. In this case, the first electrode201bof the photosensitive TFT201′ and the second electrode1013cof the driving TFT1013are connected to the same data line. The control assembly300drives the photosensitive TFT201′ and the driving TFT1013to operate in a staged manner. For example, each driving period includes a first sub-period and a second sub-period. In the first sub-period, the control assembly300supplies a first driving signal to the data line to ensure that the photosensitive TFT201′ operates, such that the irradiation position of the target light is determined. In the second sub-period, the control assembly300supplies a second driving signal to the data line to ensure that the driving TFT1013operates, such that the pixel voltage is supplied to the pixel electrode1011in the pixel region for erasure.

In the embodiments of the present disclosure, the active layer201din the photosensitive TFT201′ includes a channel region, and the channel region is a region, disposed between a region of the active layer201din contact with the first electrode201band a region of the active layer201din contact with the second electrode201c, of the active layer201d. The channel region in the active layer201din the photosensitive TFT201′ is a “-” shaped channel region, a U-shaped channel region, or a L-shaped channel region. In the present disclosure, a ratio of a long side to a short side of the channel region in the active layer201dranges from (4-10)/(2.5-6). For example, the ratio of the long side to the short side of the channel region in the active layer201dis 5/4. It should be noted that the structure of the driving TFT1013in the first substrate is the same as the structure of the photosensitive TFT201′. That is, the channel region in the active layer1013din the driving TFT1013is a “-” shaped channel region, a U-shaped channel region, or a L-shaped channel region.

In conjunction with the above two optional implementations, referring toFIG.17,FIG.17is a structural block diagram of a control assembly according to some embodiments of the present disclosure. The control assembly300includes a sensing chip301and a driving chip302. The sensing chip301is electrically connected to the driving chip302. The driving chip302in the control assembly300is electrically connected to the first substrate101in the liquid crystal panel100, and the sensing chip301in the control assembly300is electrically connected to the photosensitive assembly200. The sensing chip301determines a position of the photosensitive element201sensing the target light in the plurality of photosensitive elements201by the photosensitive assembly200, such that the position information of the pixel region for erasure is determined. Then, the sensing chip301transmits the position information of the pixel region for erasure to the driving chip302, such that the driving chip302supplies the pixel voltage to the pixel electrode in the pixel region for erasure.

For the electric connection of the control assembly300and the first substrate101, and the electric connection of the control assembly300and the photosensitive assembly200, as the structure of the photosensitive assembly200includes two optional implementations, the embodiments of the present disclosure are illustrated in the following two cases.

In a first case, in the case that the structure of the photosensitive assembly200is the structure shown in the first optional implementation, the sensing chip301in the control assembly300is electrically connected to the circuit board202in the photosensitive assembly200, and the driving chip302in the control assembly300is electrically connected to the first gate line G1and the data signal line D1in the first substrate101.

In a second case, in the case that the structure of the photosensitive assembly200is the structure shown in the second optional implementation, the sensing chip301in the control assembly300is electrically connected to the first sensing line L1and the second sensing line L2in the photosensitive assembly200, the driving chip302in the control assembly300is electrically connected to the first gate line G1and the data signal line D1in the first substrate101, and the driving chip302is further electrically connected to the second gate line G2and the photosensitive signal line D2in the photosensitive assembly200.

In the present disclosure, as shown inFIG.18andFIG.19,FIG.18is a schematic structural diagram of film layers of a liquid crystal panel according to some embodiments of the present disclosure, andFIG.19is a top view of the first substrate in the liquid crystal panel shown inFIG.18. The first substrate101in the liquid crystal handwriting board000further includes an auxiliary electrode line1018on the first base substrate1012. The auxiliary electrode line1018and the first gate line G1are disposed in the same layer, and an extension direction of the auxiliary electrode line1018and an extension direction of the first gate line G1are the same.

Illustratively, the pixel electrodes1011in the first substrate101are arranged in a plurality of rows, and a number of the auxiliary electrode lines1018in the first substrate101is equal to a number of rows of the pixel electrodes1011. An orthogonal projection of each auxiliary electrode line1018on the first base substrate1012is overlapped with an orthogonal projection of the corresponding row of pixel electrodes1011on the first base substrate1012, and the auxiliary electrode line1018and each pixel electrode1011in the row of pixel electrodes1011from a storage capacitor Cst. The storage capacitor Cst is used to maintain the pixel voltage of the pixel electrode1011. Thus, in the case that the liquid crystal handwriting board000is erased, the storage capacitor Cst avoids that a change of the voltage of the pixel electrode1011in the pixel region for erasure affects the voltages of the surrounding pixel electrode1011, and thus avoids the effect on the display effect of the pixel region surrounding the pixel region for erasure.

In some embodiments, the second substrate102in the liquid crystal panel100includes a second base substrate1022and a common electrode1021on the second base substrate1022in the second substrate102. A constant common voltage (for example, 0 V) is supplied on the common electrode1021, such that a voltage difference is present between the pixel electrode1011and the common electrode1021in the case that the pixel voltage is supplied on the pixel electrode1011. The second base substrate1022is a flexible base substrate, and the second base substrate1022is made of Polyethylene Terephthalate (PET).

In the embodiments of the present disclosure, the pixel electrode1011in the first substrate101and the common electrode1021in the second substrate102are made of indium tin oxide (ITO), indium zinc oxide (IZO), or other transparent conductive materials, such that the target light is irradiated to the photosensitive assembly200upon passing through the liquid crystal panel100.

In summary, the liquid crystal handwriting board in the embodiments of the present disclosure includes: a liquid crystal panel, a photosensitive assembly, and a control assembly. In the case that handwriting displayed on the liquid crystal handwriting board requires to be erased, an erasing tool capable of emitting target light erases the handwriting. As an orthogonal projection of a photosensitive element in the photosensitive assembly on a first substrate of the liquid crystal panel is at least partially overlapped with the corresponding pixel region, the photosensitive assembly determines a position of target light irradiated to the liquid crystal panel by detecting the target light by at least a part of photosensitive elements upon emission of the target light to the liquid crystal panel by the erasing tool, and the position of target light irradiated to the liquid crystal panel is a position of a pixel region for erasure. As such, the liquid crystal handwriting board supplies a pixel voltage to pixel electrodes in the pixel region for erasure by the control assembly, such that the erasure of the handwriting in the pixel region for erasure is achieved. In this case, even if a hand of a user is in contact with the liquid crystal handwriting board in writing, the photosensitive assembly does not determine a region in which the user is in contact with the liquid crystal handwriting board as the pixel region for erasure, such that a possibility of false erasure in the liquid crystal handwriting board is reduced, and an effect of locally erasing the liquid crystal handwriting board is efficiently improved.

The embodiments of the present disclosure further provide a handwriting system. Referring toFIG.20,FIG.20is a schematic structural diagram of a handwriting system according to some embodiments of the present disclosure. The handwriting system includes an erasing tool111and a liquid crystal handwriting board000. The liquid crystal handwriting board000is the liquid crystal handwriting board in the above embodiments, for example, the liquid crystal handwriting board shown inFIG.4,FIG.5, orFIG.13. The erasing tool111includes a light-emitting assembly111aconfigured to emit the target light. A light intensity of the target light emitted by the light-emitting assembly111arequires to be much greater than a light intensity of the ambient light, such that the photosensitive assembly200in the liquid crystal handwriting board000distinguishes the target light and the ambient light. The target light emitted by the light-emitting assembly111ais light of colors other than the green light to ensure that the target light is not reflected by the bistable liquid crystal molecules in the planar texture.

In the embodiments of the present disclosure, the liquid crystal handwriting board000is configured to determine position information of the pixel region for erasure by detecting position information of target light by the photosensitive assembly200upon emission of the target light to the liquid crystal panel100by the light-emitting assembly111aof the erasing tool111.

Illustratively, in the case that the handwriting displayed on the liquid crystal handwriting board000requires to be erased, the light-emitting assembly111aof the erasing tool111emits the target light to the pixel region for erasure in the liquid crystal panel100, and then the liquid crystal handwriting board000detects the position information of target light irradiated to the liquid crystal panel100by the photosensitive assembly200. As such, the control assembly300in the liquid crystal handwriting board000determines the position information of the pixel region for erasure by detecting the position information of the target light by the photosensitive assembly200, and supplies the pixel voltage to the pixel electrodes in the pixel region for erasure based on the position information of the pixel region for erasure, such that the handwriting in the pixel region for erasure is erased.

In some embodiments, referring toFIG.21,FIG.21is a schematic structural diagram of a liquid crystal handwriting board according to some embodiments of the present disclosure. For less power consumption of the liquid crystal handwriting board000, a switch600is disposed in the liquid crystal handwriting board000. The switch600is electrically connected to the control assembly300, and is configured to control the switch of the liquid crystal handwriting board000between an erasing mode and a writing mode. In the case that the liquid crystal handwriting board000is in the writing mode, the control assembly300and the photosensitive assembly200are in a non-operation state. In this case, the liquid crystal handwriting board000does not require to power the control assembly300and the photosensitive assembly200. In the case that the liquid crystal handwriting board000is in the erasing mode, the control assembly300and the photosensitive assembly200are in an operation state. In this case, the liquid crystal handwriting board000requires to power the control assembly300and the photosensitive assembly200. As such, the liquid crystal handwriting board000consumes the electric energy only in the erasing mode000, and the power consumption of the liquid crystal handwriting board000is efficiently reduced.

In the embodiments of the present disclosure, as shown inFIG.21, the erasing tool111in the handwriting system is further provided with a switch button111b, and the user controls the light-emitting assembly111aof the erasing tool111to emit or stop emitting the target light by pressing the switch button111bof the erasing tool111.

The embodiments of the present disclosure further provide a method for controlling a handwriting system. Referring toFIG.22,FIG.22is a flow chart of a method for controlling a handwriting system according to some embodiments of the present disclosure. The method for controlling the handwriting system is applicable to the handwriting system in the above embodiments, for example, the handwriting system shown inFIG.20orFIG.21. The method for controlling the handwriting system includes the following processes.

In S1, the liquid crystal handwriting board determines position information of a pixel region for erasure by detecting position information of 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

In S2, the liquid crystal handwriting board supplies a pixel voltage to the pixel electrodes in the pixel region for erasure based on the position information of the pixel region for erasure by the control assembly, such that a voltage difference is present between the pixel electrodes in the pixel region for erasure and the common electrode.

Those skilled in the field may clearly understand, for the convenience and simplicity of description, the specific operation principle of the above method for controlling the handwriting system can be referred to the corresponding description of the structure of the handwriting system and the structural of the liquid crystal handwriting panel in the above embodiments, which are repeated herein.

It should be noted that in the accompanying drawings, the sizes of the layers and regions may be scaled up for clarity of the illustration. It can be understood that when an element or layer is described as being “above” another element or layer, the described element or layer may be directly on the other element or layer, or an intermediate layer may exist. In addition, it can be understood that when an element or layer is described as being “below” another element or layer, the described element or layer may be directly below the other element or layer, or more than one intermediate layer or element may exist. In addition, it can also be understood that when a layer or element is described as being arranged “between” two layers or elements, the described layer or element may be the only layer between the two layers or elements, or more than one intermediate layer or element may exist. In the whole description, like reference numerals denote like elements.

In the present disclosure, the terms “first” and “second” are configured for descriptive purposes only and are not to be construed as indicating or implying relative importance. The term “a plurality of” refers to two or more, unless specifically defined otherwise.

Described above are merely exemplary embodiments of the present disclosure, and are not intended to limit the present disclosure. Any modifications, equivalent substitutions, improvements, and the like within the spirit and principles of the disclosure are included in the scope of protection of the present disclosure.