CN111781754A - Liquid crystal handwriting board capable of being partially erased - Google Patents
Liquid crystal handwriting board capable of being partially erased Download PDFInfo
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- CN111781754A CN111781754A CN201910264686.8A CN201910264686A CN111781754A CN 111781754 A CN111781754 A CN 111781754A CN 201910264686 A CN201910264686 A CN 201910264686A CN 111781754 A CN111781754 A CN 111781754A
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- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
- G02F1/1333—Constructional arrangements; Manufacturing methods
- G02F1/13338—Input devices, e.g. touch panels
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- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
- G02F1/13306—Circuit arrangements or driving methods for the control of single liquid crystal cells
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- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
- G02F1/1333—Constructional arrangements; Manufacturing methods
- G02F1/133305—Flexible substrates, e.g. plastics, organic film
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- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
- G02F1/1333—Constructional arrangements; Manufacturing methods
- G02F1/1334—Constructional arrangements; Manufacturing methods based on polymer dispersed liquid crystals, e.g. microencapsulated liquid crystals
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- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
- G02F1/1333—Constructional arrangements; Manufacturing methods
- G02F1/1339—Gaskets; Spacers; Sealing of cells
- G02F1/13392—Gaskets; Spacers; Sealing of cells spacers dispersed on the cell substrate, e.g. spherical particles, microfibres
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- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
- G02F1/1333—Constructional arrangements; Manufacturing methods
- G02F1/1343—Electrodes
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- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
- G06F3/01—Input arrangements or combined input and output arrangements for interaction between user and computer
- G06F3/03—Arrangements for converting the position or the displacement of a member into a coded form
- G06F3/041—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
- G06F3/0414—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means using force sensing means to determine a position
Abstract
The invention discloses a liquid crystal handwriting board capable of being partially erased. The liquid crystal handwriting board comprises the following components which are basically consistent in size and are arranged in a stacked mode in sequence: a substrate; a first conductive layer on the substrate; locally erasing the functional layer; a liquid crystal polymer layer; a second conductive layer; a flexible transparent substrate layer; the first conducting layer and the second conducting layer are respectively electrically connected with an external driving circuit, wherein when an area to be erased of the liquid crystal handwriting board is erased, the area to be erased is pressed, so that the voltage distributed on the local erasing function layer corresponding to the area to be erased is reduced, and the voltage distributed on the liquid crystal polymer layer corresponding to the area to be erased is increased to reach a threshold value to realize local erasing. The liquid crystal handwriting board capable of being locally erased has the advantages of simple and convenient erasing operation, low cost and no erasing trace residue.
Description
Technical Field
The invention relates to the technical field of liquid crystal application, in particular to a liquid crystal handwriting board capable of being erased locally.
Background
At present, in the fields of education, business application and the like, the liquid crystal handwriting board is more and more widely applied, and the performance requirements of the liquid crystal handwriting board promote the continuous development of the liquid crystal handwriting board technology and the updating of products. The first generation of handwriting boards are digital boards, the production equipment is expensive and difficult to master, and handwriting cannot be accurately controlled; with the rapid development of display technology, a second generation capacitive screen panel emerges, which utilizes the static electricity of a human body to realize touch operation, is sensitive to touch, but cannot perform screen touch operation after wearing gloves, cannot perform fine operation even if being matched with a professional touch pen, and is not ideal in writing experience; as a third-generation handwriting board product, the flexible liquid crystal handwriting board has the advantages that the comprehensive performance is greatly improved, based on pressure-sensitive operation, a user can control the pressure of a pen point to change the thickness of a stroke when writing and drawing, the drawing effect close to paper and the coherent experience of writing are achieved, a professional stylus is not needed, and a pencil or other hard objects can easily write color handwriting. The flexible liquid crystal handwriting board belongs to active display, does not need a backlight source and a polaroid, greatly reduces the difficulty and cost of the production process, and can realize monochrome and color display.
Most of the current commercially available liquid crystal handwriting boards are completely erased by power-up, so that the liquid crystal handwriting boards are greatly limited to enter a huge education market. Theoretically, the local erasing technique is to realize the reorientation of liquid crystal molecules in local areas, and change the reflective state into a disordered weak scattering state.
Many manufacturers have diligently studied local erase techniques, and the most common are the following three methods: 1. the thickness of the liquid crystal polymer layer is compressed, and the local electric field intensity is improved; 2. the thermal erasing technology is used for heating the liquid crystal to a clearing point and then cooling the liquid crystal to normal temperature, so that the handwriting disappears; 3. and a row-column matrix, wherein conductive film ITO (nano indium tin oxide) is etched into rows, the upper ITO and the lower ITO are vertically attached to form a row-column matrix, and row-column intersections can be erased under the control of a driving device. The method 1 has the problems of dark handwriting, large erasing force, incomplete erasing and the like; the method 2 has the problems that the heat transfer rate is slow, the wiping within 2 seconds cannot be realized, the hidden danger of scalding exists, and the energy consumption is large; the method 3 has the problems of high cost, residual handwriting, mistaken erasing and the like. The three methods only realize the productization by the method 1, and can only be applied to occasions with low erasing requirements, such as a children scrawling drawing board.
In summary, no local erasing technology capable of being applied to large-size handwriting boards exists in the current market, and the technical breakthrough is the key point that the liquid crystal handwriting boards are widely applied to the educational intelligent electronic consumer goods market.
Disclosure of Invention
The invention aims to provide a liquid crystal handwriting board capable of realizing local erasing, aiming at the technical problems in the prior art, and the liquid crystal handwriting board has the advantages of simple and convenient erasing operation, low cost and no erasing trace residue.
The invention adopts the following technical scheme:
a partially erasable liquid crystal writing pad, the liquid crystal writing pad comprising, in a substantially uniform size, in a stacked arrangement: a substrate; a first conductive layer on the substrate; locally erasing the functional layer; a liquid crystal polymer layer; a second conductive layer; a flexible transparent substrate layer; the first conducting layer and the second conducting layer are respectively electrically connected with an external driving circuit, wherein when an area to be erased of the liquid crystal handwriting board is erased, the area to be erased is pressed, so that the voltage distributed on the local erasing function layer corresponding to the area to be erased is reduced, and the voltage distributed on the liquid crystal polymer layer corresponding to the area to be erased is increased to reach a threshold value to realize local erasing.
Preferably, the local erasing function layer is a pressure-sensitive thin film conductive layer.
Preferably, the pressure-sensitive thin film conductive layer includes a polymer and a plurality of conductive particles doped in the polymer.
Preferably, the partial erasing function layer comprises a composite material film layer, a partial erasing electrode layer positioned on one side of the composite material film layer close to the substrate, and a spacer layer positioned between the first conductive layer and the partial erasing electrode layer.
Preferably, the local erase electrode layer is a patterned electrode layer.
Preferably, the spacer layer is a spacer particle layer.
Preferably, the spacer particles in the spacer particle layer define gaps between 1 μm and 50 μm.
Preferably, the local erase electrode layer is a triangle, a rectangle, a square, a circle, a diamond, a parallelogram, a trapezoid or other regular or irregular patterns formed by polygons, which are closely arranged and are independent of each other.
Preferably, the liquid crystal display further comprises an auxiliary local erasing electrode layer positioned on one side of the composite film layer close to the liquid crystal polymer layer.
Preferably, the relative dielectric constant of the composite film layer is between 20 and 200.
Preferably, the film thickness of the composite film layer is between 30 μm and 500 μm.
Preferably, the composite film layer comprises a polymer and a high dielectric constant nanomaterial doped in the polymer.
Preferably, the polymer is selected from one or more of polyethylene, polymethylmethacrylate, polyvinyl chloride, polycarbonate, polyvinylidene fluoride, urea-formaldehyde resin, unsaturated polyester resin, polytetrafluoroethylene, polyimide.
Preferably, the high dielectric constant nanomaterial is selected from one or more of silver, carbon nanotubes, conductive carbon powder, nickel, barium titanate.
Preferably, the functional localized erasure layer includes a polymer layer and a plurality of hollow microspheres dispersed in the polymer layer.
Preferably, the hollow microspheres have a diameter in the range of 20 μm to 150 μm.
Preferably, the first conductive layer and the second conductive layer are selected from one or more of ITO, graphene, nanosilver, or other metal conductive layers.
Preferably, the liquid crystal polymer layer comprises a polymer and a liquid crystal cured in the polymer.
Preferably, the liquid crystal polymer layer further comprises a plurality of liquid crystal polymer layer spacers dispersed in the polymer layer.
Preferably, the liquid crystal is a cholesteric liquid crystal.
The liquid crystal handwriting board capable of being locally erased is convenient to erase and operate, low in cost and free of erasing trace residues.
Drawings
The invention may be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a schematic cross-sectional view of a partially erasable liquid crystal writing pad according to a first embodiment of the present invention;
FIG. 2 is a schematic cross-sectional view of a partially erasable liquid crystal writing pad according to a second embodiment of the present invention;
FIG. 3 is a schematic cross-sectional view of a partially erasable liquid crystal handwriting pad according to a third embodiment of the invention;
FIG. 4 is a top view of a partially erased electrode layer in a partially erasable liquid crystal handwriting pad according to a second and third embodiment of the present invention;
FIG. 5 is a schematic diagram of another possible structure of the partially erasing electrode layer in the partially erasable liquid crystal handwriting pad according to the second and third embodiments of the invention;
fig. 6 is a schematic cross-sectional structure diagram of a partially erasable liquid crystal handwriting board according to a fourth embodiment of the invention.
Detailed Description
In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the present invention, however, it will be apparent to those skilled in the art that the present invention may be practiced without these specific details. The illustrated exemplary embodiments of the invention are provided for purposes of illustration only and are not intended to be limiting of the invention. Therefore, it is intended that the scope of the invention be limited not by this detailed description, but rather by the claims appended hereto.
The first embodiment:
fig. 1 is a schematic cross-sectional structure diagram of a liquid crystal handwriting board capable of being partially erased according to a first embodiment of the invention. As shown in fig. 1, the partially erasable liquid crystal handwriting board of the present embodiment includes, in order and in a substantially uniform size, stacked arrangement: a substrate 10; a first conductive layer 20 on the substrate 10; a local erase function layer 30; a liquid crystal polymer layer 40; a second conductive layer 50; a flexible transparent substrate layer 60. The first conductive layer 20 and the second conductive layer 50 are electrically connected to an external driving circuit 70, respectively. When an area to be erased of the liquid crystal writing pad needs to be erased, the area to be erased is pressed, so that the thickness of the local erasing function layer 30 corresponding to the area to be erased is reduced, the voltage distributed by the local erasing function layer 30 is further reduced, the voltage distributed by the liquid crystal polymer layer 40 corresponding to the area is increased, and the threshold value is reached to finally realize local erasing.
In this embodiment, the partial erasing function layer 30 is preferably a pressure-sensitive thin film conductive layer. When a force is applied to the region to be erased from the side of the flexible transparent substrate layer 60, the flexible transparent substrate layer 60 corresponding to the region is bent, and the resistance value of the pressure-sensitive film conductive layer corresponding to the region is reduced by being pressed. When a certain voltage is applied between the first conductive layer 20 and the second conductive layer 50, the resistance value of the pressure-sensitive thin film conductive layer corresponding to the region is reduced by pressing the region to be locally erased, and the voltage distributed by the pressure-sensitive thin film conductive layer is further reduced and the voltage distributed by the liquid crystal polymer layer 40 is increased, so that the voltage applied to the liquid crystal molecules in the liquid crystal polymer layer 40 corresponding to the region reaches the threshold voltage, that is, the liquid crystal molecules in the pressed region of the liquid crystal polymer layer 40 are rotated by the electric field intensity larger than that in other regions (that is, the orientation of the liquid crystal molecules is changed and the liquid crystal molecules are locally erased by changing from the reflective state to the scattering state), thereby achieving the purpose of locally erasing the region. When the liquid crystal writing pad needs to be entirely erased, the driving circuit 70 implements the entire erasure of the liquid crystal writing pad by applying a large voltage difference with respect to the partial erasure between the first conductive layer 20 and the second conductive layer 50.
In this embodiment, the pressure-sensitive thin film conductive layer used for the partial erasing functional layer 30 may be a thin film having a pressure-sensitive property formed by a single substance, or a thin film having a pressure-sensitive property formed by mixing two or more substances, for example, the pressure-sensitive thin film conductive layer includes a polymer and a plurality of conductive particles doped in the polymer. But not limited thereto, any material may be used as long as the resistance of the film itself can be changed by external pressure, and thus, the description thereof is omitted.
In the present embodiment, the first conductive layer 20 and the second conductive layer 50 are selected from one or more of ITO, graphene, nano silver, or other metal conductive layers. The first conductive layer 20 may be selected from a transparent conductive film or an opaque conductive film, and the second conductive layer 50 is selected from a transparent conductive film. The liquid crystal polymer layer 40 includes a polymer and liquid crystals cured in the polymer. Preferably, the liquid crystal polymer layer 40 further includes a plurality of liquid crystal polymer layer spacers dispersed in the polymer layer for defining a film thickness of the liquid crystal polymer layer 40. In particular embodiments of the present invention, preferably, the liquid crystal is selected from cholesteric liquid crystals.
Second embodiment:
fig. 2 is a schematic cross-sectional structure diagram of a partially erasable liquid crystal handwriting board according to a second embodiment of the invention. The same parts of this embodiment as those of the first embodiment are not repeated, and the difference is that the local erasing functional layer in the local erasing functional layer 30 in this embodiment includes a plurality of film layers. As shown in fig. 2, the partial erasing function layer 30 in the present embodiment includes a composite film layer 31, a partial erasing electrode layer 32 located on a side of the composite film layer 31 close to the substrate 10, and a spacer layer 33 located between the first conductive layer 20 and the partial erasing electrode layer 32. The composite film layer 31, the partial erase electrode layer 32, and the spacer layer 33 together constitute the partial erase function layer 30 of the present embodiment.
In this embodiment, the local erase electrode layer 32 is preferably a patterned electrode layer. Preferably, the spacer layer 33 is a spacer particle layer. The spacers in the spacer layer define gaps of between 1 μm and 50 μm, and more preferably, the spacer layer 33 has a thickness of 8 μm, 12 μm or 20 μm, for example, of between 8 μm and 20 μm. However, the spacer layer 33 may be a columnar spacer layer or another spacer layer.
In this embodiment, it is preferable that the composite film layer 31 is a high dielectric constant material, and the relative dielectric constant of the composite film layer 31 is between 20 and 200. As such, the resistance effect can be ignored to equate the liquid crystal polymer layer 40 and the composite film layer 31 as two capacitors in series. The voltage of the liquid crystal polymer layer 40 is positively correlated with the capacitance of the composite material film 31, and the capacitance is increased along with the increase of the dielectric constant of the composite material film, so that the voltage of the liquid crystal polymer layer is increased along with the increase of the capacitance, and the threshold voltage is more favorably reached. The film thickness of the composite film layer 31 is between 30 μm and 500 μm. In this embodiment, the composite film 31 includes, for example, a polymer and a high-dielectric-constant nano material doped in the polymer. Preferably, the polymer is selected from one or more of Polyethylene (PE), Polymethylmethacrylate (PMMA), polyvinyl chloride (PVC), Polycarbonate (PC), polyvinylidene fluoride (PVDF), urea-formaldehyde resin (UF), unsaturated polyester resin (UP), Polytetrafluoroethylene (PTFE), Polyimide (PI), and the like. The high dielectric constant nano material is selected from one or more of silver, carbon nano tube, conductive carbon powder, nickel and barium titanate.
In this embodiment, the patterned local erase electrode layer 32 may be squares closely arranged and independently arranged, as shown in the top view of fig. 4, for example, the side length of the square patterns is 0.5mm to 10mm, and the interval between the squares is 50 μm to 200 μm. But not limited thereto, as shown in fig. 5, the partial erase electrode layer may also be a triangular, rectangular, square, circular, diamond, parallelogram, trapezoid, regular hexagon, regular octagon, or other regular or irregular pattern composed of polygons, which are closely arranged and independently arranged from each other, and the size of the plurality of regular or irregular patterns is, for example, between 1 μm and 10 mm. The pattern of the partially-erasing electrode layer may be set as appropriate according to the specific size of the partially-erasable liquid crystal handwriting board. In this embodiment, the patterned local erase electrode layer may have the same shape or a plurality of different shapes, which is not described again. In the embodiment of the invention, the local erasing electrode layers in the to-be-erased area are arranged into the same square-shaped pattern, when local erasing is carried out, once any position of the pattern is pressed or a plurality of patterns are simultaneously pressed, the erasing area can cover the whole pressed pattern area or the plurality of pressed pattern areas, and the patterned local erasing electrode layer can be regarded as the minimum unit for carrying out local erasing.
In this embodiment, the local erasing function layer is formed by a plurality of film layers. When a force is applied to the region to be erased from one side of the flexible transparent substrate layer 60, the flexible transparent substrate layer 60 corresponding to the region is bent, so that a part of the local erasing electrode layer 32 corresponding to the region is pressed to cross the spacer particles in the spacer particle layer 33 and contact the first conductive layer 20, electrical connection is realized, the voltage of the local erasing function layer corresponding to the region is reduced, the voltage of the liquid crystal polymer layer 40 corresponding to the region is increased, and the voltage of the liquid crystal molecules in the liquid crystal polymer layer 40 corresponding to the region reaches a threshold voltage, that is, the liquid crystal molecules in the pressed region of the liquid crystal polymer layer 40 are rotated by a larger electric field intensity than that of other regions, that is, the orientation of the liquid crystal molecules is changed, and the orientation is changed from a reflective state to a scattering state, so that the purpose of locally erasing the region is achieved. When the liquid crystal writing pad needs to be entirely erased, the driving circuit 70 implements the entire erasure of the liquid crystal writing pad by applying a large voltage difference with respect to the partial erasure between the first conductive layer 20 and the second conductive layer 50.
In this embodiment, for example, the composite film layer 31 has a thickness of 30 μm, a dielectric constant of 30, a resistivity of greater than 1010 Ω · cm and a black color, the lower surface of the composite film layer is coated with a silver electrode and etched to form a patterned local erase electrode layer 32, the pattern of the local erase electrode layer 32 is 10mm × 10mm square, the gap is 0.2mm, the flexible transparent substrate layer 60 is made of transparent flexible PET, the thickness of the flexible transparent substrate layer 60 is 180 μm, and the spacer layer 33 is made of spherical spacerA seed support with a particle size of 20 μm and a density of 5 particles/mm2. In the sample preparation process of this embodiment, for example, the substrate 10 is glass, the first conductive layer 20 is ITO, the substrate 10 having the first conductive layer 20 is cleaned and sprayed with spacers, the liquid crystal polymer layer 40 is dropped between the composite film layer 31 and the flexible transparent substrate 60, and the substrate is processed into a film by a rolling method and then attached to the glass substrate 10 on which the ITO layer (first conductive layer) is formed to prepare a sample. 150V square wave voltage is applied between the first conductive layer and the second conductive layer, and the local erasing part is pressed, so that the handwriting completely disappears and has no residue, and the design requirement is further met.
The third embodiment:
fig. 3 is a schematic cross-sectional structure diagram of a liquid crystal handwriting board capable of being partially erased according to a third embodiment of the invention. The same parts of this embodiment as the second embodiment are not repeated, and the difference is that the local erasing function layer 30 in this embodiment further includes an auxiliary local erasing electrode layer 34 located on one side of the composite material film layer 31 close to the liquid crystal polymer layer 40.
In this embodiment, the auxiliary local erase electrode layer 34 and the local erase electrode layer 32 may be set to have the same pattern or different patterns, and the patterns of the auxiliary local erase electrode layer 34 and the local erase electrode layer 32 may be correspondingly set in position or may be staggered, so long as the function of local erase of the present invention can be implemented, and will not be described again.
When the area of the liquid crystal writing pad of this embodiment which needs to be partially erased is pressed by a force from the side of the flexible transparent base material layer 60, the flexible transparent substrate layer 60 corresponding to the region is bent such that a portion of the local erase electrode layer 32 corresponding to the region contacts the first conductive layer 20 by being pressed across the spacer in the spacer layer 33, achieving electrical connection, so that the voltage applied to the local erase function layer 30 corresponding to the region is lowered and the voltage applied to the liquid crystal polymer layer 40 is raised, so that the voltage applied to the liquid crystal molecules in the liquid crystal polymer layer 40 corresponding to the region reaches the threshold voltage, that is, the liquid crystal molecules in the region of the liquid crystal polymer layer 40 to be pressed are rotated by the electric field intensity larger than that in the other region (that is, the orientation of the liquid crystal molecules is changed from the reflective state to the scattering state), so that the region is locally erased. When the liquid crystal writing pad needs to be entirely erased, the driving circuit 70 implements the entire erasure of the liquid crystal writing pad by applying a large voltage difference with respect to the partial erasure between the first conductive layer 20 and the second conductive layer 50.
In this embodiment, for example, the composite film layer 31 has a thickness of 50 μm, a dielectric constant of 45, a resistivity greater than 1010 Ω · cm, and a black color, and the silver electrodes are respectively evaporated on the upper and lower surfaces thereof and etched to form the patterned local erase electrode layer 32 and the auxiliary local erase electrode layer 34, where the patterns of the local erase electrode layer 32 and the auxiliary local erase electrode layer 34 are both squares of 10mm × 10mm, and the gap is 0.2 mm; the flexible transparent substrate layer 60 is made of transparent flexible PET, and the thickness of the flexible transparent substrate layer 60 is 180 micrometers; the spacer layer 33 is supported by a photo-lithographically formed columnar spacer having a diameter of 70 μm and a height of 12 μm, and the columnar spacers are regularly arranged at an interval of 5mm from top to bottom and from left to right. In the sample preparation process of this embodiment, for example, the substrate 10 is glass, the first conductive layer 20 is ITO, the liquid crystal polymer layer 40 is dropped between the composite film layer 31 and the flexible transparent substrate layer 60, and the liquid crystal polymer layer is processed into a film by a rolling method and then attached to the glass substrate 10 on which the ITO layer (first conductive layer) is formed to prepare a sample. And applying 100V square wave voltage between the first conductive layer and the second conductive layer, and pressing the local erasing part, so that the handwriting completely disappears and has no residue, thereby further meeting the design requirement.
Compared with the second embodiment, the present embodiment additionally provides the auxiliary local erase electrode layer 34, and the auxiliary local erase electrode layer 34 has the same pattern and the corresponding position as the local erase electrode layer 32, and during the local erase process, the provision of the auxiliary local erase electrode layer 34 is more beneficial to further lowering the voltage distributed to the local erase function layer 30 and further raising the voltage distributed to the liquid crystal polymer layer 40, so that the present embodiment has a better local erase effect compared with the second embodiment.
The fourth embodiment:
fig. 6 is a schematic cross-sectional structure diagram of a partially erasable liquid crystal handwriting board according to a fourth embodiment of the invention. The same parts of this embodiment as those of the first embodiment are not repeated, but the difference is that the local erasing functional layer 30 adopted in the local erasing functional layer 30 in this embodiment includes a polymer layer 301 and a plurality of hollow microspheres 302 dispersed in the polymer layer 301, and in this embodiment, the diameter of the hollow microspheres 302 is preferably within a range of 20 μm to 150 μm.
In this embodiment, the local erasing function layer 30 is an elastic film layer. When a force is applied to the region to be erased from the side of the flexible transparent substrate layer 60, the flexible transparent substrate layer 60 corresponding to the region is bent, so that the thickness of the partial erasing function layer corresponding to the region is reduced by being pressed. When the voltage applied between the first conductive layer 20 and the second conductive layer 50 is constant, the local erasing function layer 30 corresponding to the region is reduced in thickness by pressing the region to be locally erased, so that the voltage applied to the local erasing function layer 30 corresponding to the region is reduced, and the voltage applied to the liquid crystal polymer layer 40 corresponding to the region is increased, so that the voltage applied to the liquid crystal molecules in the liquid crystal polymer layer 40 corresponding to the region reaches the threshold voltage, that is, the liquid crystal molecules in the pressed region of the liquid crystal polymer layer 40 are rotated (i.e., the orientation of the liquid crystal molecules is changed, and the liquid crystal molecules are changed from the reflective state to the scattering state) by the electric field intensity higher than that of other regions, thereby achieving the purpose of locally erasing the region. When the liquid crystal writing pad needs to be entirely erased, the driving circuit 70 implements the entire erasure of the liquid crystal writing pad by applying a large voltage difference with respect to the partial erasure between the first conductive layer 20 and the second conductive layer 50.
In this embodiment, the material used for the local erasing function layer 30 may also be a film made of a single substance and having excellent elastic deformation performance, and has good thickness recovery performance after being pressed; or an elastic film formed by mixing two or more substances. The present invention is not limited thereto, and any material may be used as long as it has a thickness that can be changed by external pressure and can be restored in time or nearly restored to its original state after the pressure is released, and will not be described in detail.
The principle of the liquid crystal handwriting board capable of being locally erased of the specific embodiment of the invention for realizing local erasing is as follows: the composite material film layer and the liquid crystal polymer layer can be equivalent to a series circuit, a sufficiently high voltage is applied to a local area to be erased from the outer side of the film layer clamping the liquid crystal polymer layer, and when the voltage obtained by dividing the liquid crystal polymer layer reaches a threshold value, the erasure of writing in the local area can be realized; generally, the film material of the liquid crystal handwriting pad is a PET material, and the divided voltage of the liquid crystal handwriting pad is far greater than that of the liquid crystal polymer layer, so that the voltage required for achieving erasing is extremely high, and the local erasing function is difficult to achieve. The invention can successfully reduce the erasing voltage to a safe range by arranging the pressure-sensitive resistance film, the elastic film or improving the dielectric constant of the composite film. The equivalent circuit of the common film can adopt series-parallel connection equivalent of resistance and capacitance, because the dielectric constant of the composite material film layer is very high, the resistance effect can be ignored, so that the liquid crystal polymer layer and the composite material film layer are equivalent to two capacitors which are connected in series, the voltage obtained by the liquid crystal polymer layer is positively correlated with the capacitance value of the composite material film layer, the capacitance value is increased along with the increase of the dielectric constant of the composite material film layer, the voltage obtained by the liquid crystal polymer layer is increased along with the increase of the capacitance value, and therefore when the dielectric constant of the composite material film layer is high to a certain value, the liquid crystal layer phase state can be converted by applying driving voltage on the film by using low.
It should be noted that, the invention mainly reduces the driving voltage by adjusting the resistance or the thickness of the local erasing functional layer or adjusting the dielectric constant of the composite material film layer, but two or more parameters of the resistance, the thickness and the dielectric constant of the local erasing functional layer can be adjusted at the same time to achieve the purpose of the invention, and the invention can be implemented as long as the design concept of the invention is met, and is not described again.
The local erasing functional layer and the liquid crystal polymer layer are relatively independent and do not influence each other, the parameters of the local erasing functional layer and the liquid crystal polymer layer are easier to adjust to achieve the optimal driving effect, the erasing operation is convenient, the cost is low, and no erasing trace residue exists. The problems of large erasing force, residual traces, high cost, dark handwriting, untimely response and the like of other local erasing methods are well avoided.
The technical principle of the present invention is described above in connection with specific embodiments. The description is made for the purpose of illustrating the principles of the invention and should not be construed in any way as limiting the scope of the invention. Based on the explanations herein, those skilled in the art will be able to conceive of other embodiments of the present invention without inventive effort, which would fall within the scope of the present invention.
Claims (20)
1. A partially erasable liquid crystal writing pad, comprising, in a substantially uniform size, in a stacked arrangement:
a substrate;
a first conductive layer on the substrate;
locally erasing the functional layer;
a liquid crystal polymer layer;
a second conductive layer;
a flexible transparent substrate layer;
the first conducting layer and the second conducting layer are respectively electrically connected with an external driving circuit, wherein when an area to be erased of the liquid crystal handwriting board is erased, the area to be erased is pressed, so that the voltage distributed on the local erasing function layer corresponding to the area to be erased is reduced, and the voltage distributed on the liquid crystal polymer layer corresponding to the area to be erased is increased to reach a threshold value to realize local erasing.
2. The liquid crystal writing pad of claim 1, wherein the partially-erasable functional layer is a pressure-sensitive thin film conductive layer.
3. The partially erasable liquid crystal writing pad of claim 2, wherein the pressure sensitive thin film conductive layer comprises a polymer and a plurality of conductive particles doped in the polymer.
4. The partially erasable liquid crystal writing pad of claim 1, wherein said partially erasable functional layer comprises a composite film layer, a partially erasable electrode layer on a side of said composite film layer adjacent to said substrate, and a spacer layer between said first electrically conductive layer and said partially erasable electrode layer.
5. The partially erasable liquid crystal writing pad of claim 4, wherein the partially erasable electrode layer is a patterned electrode layer.
6. The partially erasable liquid crystal writing pad of claim 4, wherein the spacer layer is a spacer particle layer.
7. The partially erasable liquid crystal writing pad of claim 6, wherein the spacers in the spacer layer define a gap between 1 μm and 50 μm.
8. The liquid crystal handwriting board capable of being locally erased according to claim 4, wherein the local erasing electrode layer is a triangular, rectangular, square, circular, rhombic, parallelogram, trapezoid or other regular or irregular pattern formed by polygons, which are closely arranged and arranged independently of each other.
9. The liquid crystal writing pad of claim 4, further comprising an auxiliary partially-erasing electrode layer on a side of the composite film layer adjacent to the liquid crystal polymer layer.
10. The liquid crystal writing pad of claim 4, wherein the composite film layer has a relative dielectric constant between 20 and 200.
11. The liquid crystal writing pad of claim 4, wherein the composite film layer has a thickness of between 30 μm and 500 μm.
12. The partially erasable liquid crystal writing pad of claim 4, wherein the composite film layer comprises a polymer and a high dielectric constant nanomaterial doped in the polymer.
13. The locally erasable liquid crystal tablet of claim 12, wherein the polymer is selected from one or more of polyethylene, polymethylmethacrylate, polyvinyl chloride, polycarbonate, polyvinylidene fluoride, urea-formaldehyde resin, unsaturated polyester resin, polytetrafluoroethylene, polyimide.
14. The partially erasable liquid crystal writing pad of claim 12, wherein the high dielectric constant nanomaterial is selected from one or more of silver, carbon nanotubes, conductive carbon powder, nickel, barium titanate.
15. The partially-erasable liquid crystal writing pad of claim 1, wherein the partially-erasable functional layer comprises a polymer layer and a plurality of hollow microspheres dispersed in the polymer layer.
16. The partially erasable liquid crystal writing pad of claim 15, wherein the hollow microspheres have a diameter in a range of 20 μ ι η to 150 μ ι η.
17. The partially erasable liquid crystal writing pad of claim 1, wherein the first and second conductive layers are selected from one or more of ITO, graphene, nanosilver, or other metallic conductive layers.
18. The partially erasable liquid crystal tablet of claim 1, wherein the liquid crystal polymer layer comprises a polymer and liquid crystals cured in the polymer.
19. The partially erasable liquid crystal writing pad of claim 18, wherein the liquid crystal polymer layer further comprises a plurality of liquid crystal polymer layer spacers dispersed in the polymer layer.
20. The partially erasable liquid crystal tablet of claim 18, wherein said liquid crystal is cholesteric liquid crystal.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
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| CN201910264686.8A CN111781754B (en) | 2019-04-03 | 2019-04-03 | Liquid crystal handwriting board capable of being partially erased |
| PCT/CN2020/082061 WO2020200164A1 (en) | 2019-04-03 | 2020-03-30 | A selectively erasable liquid crystal writing board |
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| CN201910264686.8A CN111781754B (en) | 2019-04-03 | 2019-04-03 | Liquid crystal handwriting board capable of being partially erased |
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| CN111781754B CN111781754B (en) | 2021-11-09 |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112327546A (en) * | 2020-11-18 | 2021-02-05 | 京东方科技集团股份有限公司 | Liquid crystal handwriting board, handwriting device and control method of handwriting device |
| CN112987366A (en) * | 2021-02-04 | 2021-06-18 | 业成科技（成都）有限公司 | Electronic handwriting board and application method thereof and terminal equipment |
| CN113552971A (en) * | 2021-08-11 | 2021-10-26 | 京东方科技集团股份有限公司 | Liquid crystal handwriting board system and erasing method |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1992008160A1 (en) * | 1990-10-24 | 1992-05-14 | Greyhawk Systems, Inc. | Apparatus for and method of operation of smectic liquid crystal light valve |
| CN1773329A (en) * | 2005-10-17 | 2006-05-17 | 北京科技大学 | Method for erazing or writing cholesteryl phase liquid crystal stored information |
| US20090033811A1 (en) * | 2007-07-31 | 2009-02-05 | Kent Displays Incorporated | Multiple color writing tablet |
| CN102654805A (en) * | 2011-08-03 | 2012-09-05 | 京东方科技集团股份有限公司 | Electronic handwriting screen |
| CN104749852A (en) * | 2013-12-27 | 2015-07-01 | 元太科技工业股份有限公司 | Electronic writing device and driving method thereof |
| CN106646977A (en) * | 2017-01-13 | 2017-05-10 | 深圳市好写科技有限公司 | Local-erasing liquid-crystal display device |
| CN208092390U (en) * | 2018-05-08 | 2018-11-13 | 深圳市德安里科技有限公司 | A kind of liquid crystal board |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9235096B2 (en) * | 2013-08-26 | 2016-01-12 | Kent Displays Incorporated | Inductive switching of cholesteric liquid crystal display device |
| CN107820582A (en) * | 2015-04-28 | 2018-03-20 | 唯酷有限公司 | Liquid crystal writing equipment |
| CN107066153A (en) * | 2017-04-21 | 2017-08-18 | 深圳市屏柔科技有限公司 | A kind of intelligent flexible liquid crystal blackboard that key erasing and selective erase can be achieved |
| CN207529068U (en) * | 2017-10-23 | 2018-06-22 | 深圳市鸿合创新信息技术有限责任公司 | It is a kind of can selective erase liquid crystal writing plate |
| CN107728398B (en) * | 2017-11-03 | 2023-04-11 | 好易写（深圳）科技有限公司 | Liquid crystal writing board system and erasing method thereof |
| CN108828821B (en) * | 2018-06-28 | 2021-01-12 | 广州林登科技有限公司 | Liquid crystal writing device capable of being locally erased and local erasing method |
-
2019
- 2019-04-03 CN CN201910264686.8A patent/CN111781754B/en active Active
-
2020
- 2020-03-30 WO PCT/CN2020/082061 patent/WO2020200164A1/en active Application Filing
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1992008160A1 (en) * | 1990-10-24 | 1992-05-14 | Greyhawk Systems, Inc. | Apparatus for and method of operation of smectic liquid crystal light valve |
| CN1773329A (en) * | 2005-10-17 | 2006-05-17 | 北京科技大学 | Method for erazing or writing cholesteryl phase liquid crystal stored information |
| US20090033811A1 (en) * | 2007-07-31 | 2009-02-05 | Kent Displays Incorporated | Multiple color writing tablet |
| CN102654805A (en) * | 2011-08-03 | 2012-09-05 | 京东方科技集团股份有限公司 | Electronic handwriting screen |
| CN104749852A (en) * | 2013-12-27 | 2015-07-01 | 元太科技工业股份有限公司 | Electronic writing device and driving method thereof |
| CN106646977A (en) * | 2017-01-13 | 2017-05-10 | 深圳市好写科技有限公司 | Local-erasing liquid-crystal display device |
| CN208092390U (en) * | 2018-05-08 | 2018-11-13 | 深圳市德安里科技有限公司 | A kind of liquid crystal board |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112327546A (en) * | 2020-11-18 | 2021-02-05 | 京东方科技集团股份有限公司 | Liquid crystal handwriting board, handwriting device and control method of handwriting device |
| CN112327546B (en) * | 2020-11-18 | 2023-11-03 | 京东方科技集团股份有限公司 | Liquid crystal handwriting board, handwriting device and control method of handwriting device |
| CN112987366A (en) * | 2021-02-04 | 2021-06-18 | 业成科技（成都）有限公司 | Electronic handwriting board and application method thereof and terminal equipment |
| CN112987366B (en) * | 2021-02-04 | 2022-09-20 | 业成科技（成都）有限公司 | Electronic handwriting board and application method thereof and terminal equipment |
| CN113552971A (en) * | 2021-08-11 | 2021-10-26 | 京东方科技集团股份有限公司 | Liquid crystal handwriting board system and erasing method |
| CN113552971B (en) * | 2021-08-11 | 2024-01-23 | 京东方科技集团股份有限公司 | Liquid crystal handwriting board system and erasing method |
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| Publication number | Publication date |
|---|---|
| CN111781754B (en) | 2021-11-09 |
| WO2020200164A1 (en) | 2020-10-08 |
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