CN117452729A - Erasing control method and device for liquid crystal writing device - Google Patents

Erasing control method and device for liquid crystal writing device Download PDF

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Publication number
CN117452729A
CN117452729A CN202311756723.XA CN202311756723A CN117452729A CN 117452729 A CN117452729 A CN 117452729A CN 202311756723 A CN202311756723 A CN 202311756723A CN 117452729 A CN117452729 A CN 117452729A
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liquid crystal
voltage
conductive layer
erasing
erase
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CN117452729B (en
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李清波
杨猛训
李泉堂
李瑞瑞
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Shandong Lanbei Yishu Information Technology Co ltd
Shandong Lanbeisite Educational Equipment Group
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Shandong Lanbei Yishu Information Technology Co ltd
Shandong Lanbeisite Educational Equipment Group
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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
    • G02F1/137—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 characterised by the electro-optical or magneto-optical effect, e.g. field-induced phase transition, orientation effect, guest-host interaction or dynamic scattering
    • G02F1/139—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 characterised by the electro-optical or magneto-optical effect, e.g. field-induced phase transition, orientation effect, guest-host interaction or dynamic scattering based on orientation effects in which the liquid crystal remains transparent
    • G02F1/1391—Bistable or multi-stable liquid crystal cells

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  • Physics & Mathematics (AREA)
  • Nonlinear Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Liquid Crystal (AREA)

Abstract

The invention relates to the technical field of erasing of liquid crystal writing devices, and particularly discloses a method and a device for controlling the erasing of a liquid crystal writing device, wherein the method comprises the following steps: determining an erase start voltage V st Applying a first voltage V to a conductive region on the first conductive layer covering the target erase region 1 Applying a second voltage V to other conductive areas on the first conductive layer 2 The method comprises the steps of carrying out a first treatment on the surface of the Applying a third voltage V to the conductive region on the second conductive layer covering the target erase region 3 Applying a fourth voltage V to other conductive areas on the second conductive layer 4 The method comprises the steps of carrying out a first treatment on the surface of the The method meets the following conditions:，the method comprises the steps of carrying out a first treatment on the surface of the The invention can reduce the energy required by erasure as much as possible.

Description

Erasing control method and device for liquid crystal writing device
Technical Field
The invention relates to the technical field of local erasure of a liquid crystal writing device, in particular to an erasure control method and an erasure control device of the liquid crystal writing device.
Background
At present, the erasing modes of the bistable liquid crystal writing device mainly comprise two modes of local erasing and one-key erasing; under the two modes, a certain voltage is applied to the upper conductive layer and the lower conductive layer to realize erasure, so that most of the liquid crystal writing devices are provided with batteries as power supplies at present, and of course, some liquid crystal writing devices support external power supply and battery power supply at the same time.
In the prior art, when the erasing of the liquid crystal writing device is realized, only how to ensure the erasing effect is mostly considered, especially when the liquid crystal writing device is locally erased, the target erasing area needs to be ensured to be completely erased, and other areas are not affected, but the problem of energy consumed by the erasing is often ignored, so that the problems of overlarge erasing energy, overlarge battery power consumption and the like can be caused, and the use experience of a user can be influenced.
Therefore, how to reduce the erasing energy as much as possible while ensuring the erasing effect and to prolong the service time of the power supply battery as much as possible are key to improving the user experience.
Disclosure of Invention
The first object of the present invention is to disclose a liquid crystal writing device erase control method capable of achieving quick erasure of a target erase area while other areas are not affected, on the premise that required erase energy is as small as possible.
In order to achieve the above purpose, the present invention adopts the following technical scheme:
an erasure control method of a liquid crystal writing device, wherein a bistable liquid crystal layer is positioned between a first conductive layer and a second conductive layer, and the two conductive layers are respectively divided into more than two mutually insulated conductive areas; the erasure control method comprises the following steps:
determining an erase onset voltage V for a liquid crystal writing device st ;
Applying a first voltage V to a conductive region on a first conductive layer covering a target erase region 1 Applying a second voltage V to other conductive areas on the first conductive layer 2 The method comprises the steps of carrying out a first treatment on the surface of the Applying a third voltage V to the conductive region on the second conductive layer covering the target erase region 3 Applying a fourth voltage V to other conductive areas on the second conductive layer 4 The method comprises the steps of carrying out a first treatment on the surface of the Therefore, the target erasing area can be completely erased in an energy-saving mode, and other areas are not affected;
wherein the first voltageV 1 And a third voltageV 3 The method meets the following conditions:
；
；
；
；
；
r is equivalent alternating current impedance between the upper conductive layer and the lower conductive layer of the target erasing area, E is the minimum value of energy required by liquid crystal inversion of the target erasing area, and T is the time used for erasing; t is not less than the erase response time T of the liquid crystal E ；V D The initial voltage is the initial voltage when the liquid crystal state is changed from the focal conic state to the vertical cross-structure state.
Further, the T andfurther satisfies: />At this time, it can be considered that the partial erase is realized in a power-saving manner.
Wherein the second voltage and the fourth voltage satisfy:
。
alternatively, when the first voltage V 1 And a third voltage V 3 The method meets the following conditions:
；
and the erase time T is equal to the erase response time T of the liquid crystal E When the required erasing energy is minimum;
wherein the voltage V E The voltage applied to enable the bistable liquid crystal in a certain region to be completely inverted from the planar state to the focal conic state.
A second object of the present invention is to disclose a liquid crystal writing apparatus comprising: the bistable liquid crystal display comprises a first conductive layer, a bistable liquid crystal layer and a second conductive layer which are sequentially arranged, wherein the bistable liquid crystal layer is positioned between the first conductive layer and the second conductive layer, and the two conductive layers are respectively divided into more than two mutually insulated conductive areas; the local erasure is realized by adopting the erasure control method.
A third object of the present invention is to disclose a method for controlling erasure of a liquid crystal writing device, wherein a bistable liquid crystal layer is located between a first conductive layer and a second conductive layer, and both conductive layers are not divided, the method comprising:
determining an erase onset voltage V for a liquid crystal writing device st ;
Applying a first voltage V to the first conductive layer 1 Applying a third voltage V to the second conductive layer 3 The liquid crystal writing device can be completely erased in an energy-saving mode;
wherein the first voltage V 1 And a third voltage V 3 The method meets the following conditions:
；
；
；
；
r is equivalent alternating current impedance between the upper conductive layer and the lower conductive layer, E is the minimum energy value required by liquid crystal inversion, and T is the time for erasing; t is not less than the erase response time T of the liquid crystal E ；V D The initial voltage is the initial voltage when the liquid crystal state is changed from the focal conic state to the vertical cross-structure state.
A fourth object of the present invention is to disclose a liquid crystal writing apparatus comprising: the first conductive layer, the bistable liquid crystal layer and the second conductive layer are sequentially arranged, the bistable liquid crystal layer is positioned between the first conductive layer and the second conductive layer, the two conductive layers are not divided, and the one-key erasure is realized by adopting the erasure control method.
Compared with the prior art, the invention has the beneficial effects that:
(1) For two erasure modes of one-key erasure and local erasure, the invention provides a method for reducing erasure energy as much as possible while ensuring erasure effect, can finish local erasure with minimum energy, prolongs the service time of a power supply battery, avoids frequent battery replacement and improves user experience.
(2) The invention is realized by reasonably selecting T andthe value of (2) can select a compromise between the erasing time and the erasing voltage, or reasonably adjust the erasing time and the erasing voltage according to actual requirements;the method realizes the complete erasure of the target erasure area in an energy-saving way as much as possible, and can ensure the erasure effect.
Drawings
The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiments of the application and together with the description serve to explain the application and do not constitute an undue limitation to the application.
FIG. 1 is a diagram showing the relationship between bistable liquid crystal states and voltages according to an embodiment of the present invention;
FIG. 2 shows an erase response time T in an embodiment of the present invention E And voltage ofIs a schematic diagram of the relationship of (1);
FIG. 3 shows erase energy and voltage in an embodiment of the present inventionIs a schematic diagram of the relationship of (1);
FIG. 4 is a schematic diagram showing the voltage application of the first half field during partial erase in accordance with an embodiment of the present invention;
FIG. 5 is a schematic diagram showing the voltage application of the second half field during partial erase in an embodiment of the present invention;
fig. 6 is a schematic structural diagram of a liquid crystal writing device according to an embodiment of the present invention.
Detailed Description
It should be noted that the following detailed description is illustrative and is intended to provide further explanation of the present application. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.
It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments in accordance with the present application. As used herein, the singular is also intended to include the plural unless the context clearly indicates otherwise, and furthermore, it is to be understood that the terms "comprises" and/or "comprising" when used in this specification are taken to specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof.
The liquid crystal writing device of the present invention, based on the bistable character of the liquid crystal, when the liquid crystal writing device receives writing pressure, the bistable liquid crystal at the pressure applying position becomes a planar state (planar state), thereby displaying the written contents on the writing panel; when a voltage is applied to the bistable liquid crystal, the bistable liquid crystal state is turned over, and the plane state is changed into a focal conic state (focal conic state), so that the written contents can be erased.
A diagram showing bistable liquid crystal state and voltage relationship, voltage V, shown in FIG. 1 st An erase start voltage is realized when the liquid crystal state is changed from a planar state to a focal conic state, wherein the erase start voltage is a voltage V reached by a voltage difference between upper and lower conductive layers in a certain region st When bistable liquid crystal in the area starts to turn over (so-called part turns over, industry practice generally considers that at least 10% of liquid crystal is changed from a plane state to a focal conic state, and the prior art can be measured by a liquid crystal comprehensive parameter tester, but a certain measurement error can also exist, the error range is within +/-5%, the more uniform the liquid crystal is coated, the higher the identification precision is); as the voltage difference continues to increase, more bistable liquid crystals are turned over in the region; when the voltage difference reaches V E When bistable liquid crystals in this region are fully inverted to the focal conic state (so-called full inversion, industry practice generally considers that at least 90% of the liquid crystals change from planar to focal conic state, as can be measured by the liquid crystal integrated parameter tester of the prior art).
Voltage V D An initial voltage when the liquid crystal state is changed from a focal conic state to a vertical cross-structure state (homeotropic state); the starting voltage refers to: when the voltage applied to the liquid crystal reaches a certain voltage, a part of the liquid crystal (as above, at least 10% of the liquid crystal is normally considered to be turned over) is in a vertical cross-sectional state, when the voltage difference reaches V H The bistable liquid crystal in this region is fully inverted (as above, it is generally believed that at least 90% or more of the liquid crystal is inverted) to a homeotropic state.
It should be noted that, perpendicular intersecting structureThe state is not steady state, requires the application of a voltage to maintain, and moreover, the liquid crystal is transparent in the vertical cross-structure state, as the focal conic state behaves; when the voltage applied in the vertical cross-structure state is rapidly removed, the liquid crystal is changed from the vertical cross-structure state into a plane state, and can be used for display at the moment; when the voltage applied in the vertical cross-structure state is slowly withdrawn, the liquid crystal is changed from the vertical cross-structure state into a focal conic state, and the liquid crystal can be erased at the moment, but the quick erase can not be realized due to the long slow discharge time, and meanwhile, the voltage V D Higher, energy-saving erasure is not possible.
In addition, according to the material and thickness of the liquid crystal, the voltage V st 、V E 、V D And V H Specific measured values will also vary accordingly, and their specific values may be measured on a specific liquid crystal basis.
Example 1
The embodiment particularly discloses an erasure control method of a liquid crystal writing device, which is suitable for a local erasure mode; the liquid crystal writing device comprises a first conductive layer, a bistable liquid crystal layer and a second conductive layer; the bistable liquid crystal layer is positioned between the first conductive layer and the second conductive layer, and the first conductive layer and the second conductive layer are respectively divided into more than two mutually insulated conductive areas;
the erasure control method specifically comprises the following steps:
determining an erase onset voltage V for a liquid crystal writing device st Erase initiation voltage V st Refers to a voltage required to turn over the bistable liquid crystal starting portion of a certain region;
applying a first voltage V to a conductive region on a first conductive layer covering a target erase region 1 Applying a second voltage V to other conductive areas on the first conductive layer 2 The method comprises the steps of carrying out a first treatment on the surface of the Applying a third voltage V to the conductive region on the second conductive layer covering the target erase region 3 Applying a fourth voltage V to other conductive areas on the second conductive layer 4 The method comprises the steps of carrying out a first treatment on the surface of the Therefore, the target erasing area can be completely erased in an energy-saving mode, and other areas are not affected;
wherein the first voltage V 1 And thirdVoltage V 3 The method meets the following conditions:
（1）
（2）
（3）
（4）
（5）
r is equivalent alternating current impedance between the upper conductive layer and the lower conductive layer of the target erasing area, E is the minimum energy required by liquid crystal inversion of the target erasing area, and the minimum energy required by liquid crystal inversion refers to the minimum energy required by all liquid crystal molecules of the target erasing area to be overturned from a planar state to a focal conic state.
T is the erasing time, T is not less than the erasing response time T of the liquid crystal E Also, T is typically less than 200 milliseconds in order to ensure that no significant delay is seen by the human eye when performing a partial erase.
Erase response time T of liquid crystal E Refers to: and after the set erasing voltage is applied, the time required for the liquid crystal molecules to be completely overturned from the plane state to the focal conic state is shortened. T (T) E Is related to the applied voltage, liquid crystal formulation, liquid crystal thickness, and insulating layer thickness curing process. It can be appreciated that when the applied voltages are different for different liquid crystals, the erase response time T of the resulting liquid crystals E Will also be different, FIG. 2 shows the erase response time T E With applied voltageIs a schematic diagram of the relationship of (1); t (T) E The specific value of (2) may be measured based on the specific liquid crystal and applied voltage. Such as: when->Greater than or equal to V E At the time T E Typically between a few milliseconds and tens of milliseconds; while->Less than V E At the time T E May reach several hundred milliseconds.
V D The initial voltage is the initial voltage when the liquid crystal state is changed from the focal conic state to the vertical cross-structure state. As already previously analyzed, whenWhen local erasure may not be achieved; alternatively, although it can be used for local erasure, erasure is slow and the required energy is high, and energy saving cannot be achieved.
In this embodiment, the liquid crystal is selected to satisfy V E ≤3V st The method comprises the steps of carrying out a first treatment on the surface of the Because when V E ＞3V st At the time, a proper voltage V cannot be selected 2 And V 4 To ensure that the non-erased areas are unaffected.
As before, the so-called partial inversion of this embodiment is generally considered to be at least 10% inversion of the liquid crystal; the so-called total inversion is generally considered to be at least 90% inversion of the liquid crystal.
Meanwhile, the second voltage and the fourth voltage also satisfy:
（6）
。
at this time, only the voltage difference of the target erasing area reaches the erasing initial voltage, and the voltage differences of the other areas are smaller than the erasing initial voltage; therefore, only the target erase region can be erased, while other regions are not affected.
The embodiment described in this embodiment can achieve complete erasure of the target erase region in a power-efficient manner, while other regions are unaffected, by the rational choice of T and TThe erase energy can be controlled to be as small as possible while ensuring that the target erase region is completely erased, while other regions are unaffected.
Further, by rational choice of T andthe value of (2) is such that ∈>When the energy-saving erasure is considered to be realized.
This embodiment is achieved by a rational choice of T anda reasonable compromise can be found between the erase time and the erase voltage; or the erasing time and the erasing voltage can be reasonably allocated according to the actual demands of users, so that the target erasing area can be completely erased in an energy-saving mode as much as possible, and other areas are not affected.
As a further alternative, if the third voltage V 3 For the reference value, i.e. zero potential, the specific value ranges of the second voltage and the fourth voltage are provided in this embodiment, namely, the following conditions are satisfied:
。（7）
in this case, a better partial erase effect can be achieved.
In the present embodiment, whenDuring the erase time T, +.>The value of (2) needs to be inverted every set time, so that the target erase region can be ensured to be completely erased.
Specifically, the negation refers to: applying a voltage difference between the upper conductive layer and the lower conductive layerAs the first half field, the difference between the applied voltages of the upper conductive layer and the lower conductive layer is +.>As the second half field. That is, the upper conductive layer has a higher potential than the lower conductive layer in the upper half field, and the upper conductive layer has a lower potential than the lower conductive layer in the lower half field.
Referring to FIG. 4, in the first half of the voltage application, the voltage difference between the upper and lower conductive layers of the target erase region isThe voltage difference between the upper conductive layer and the lower conductive layer of the other non-erasing area is +.>、/>And->. Referring to FIG. 5, in the latter half of the voltage application, the voltage difference between the upper and lower conductive layers of the target erase region is +.>Between upper and lower conductive layers in other non-erased areasDifferential pressure of +.>、/>And->. The complete erasure of the target erasure area can be achieved by constantly alternating the first half field and the second half field.
Of course, whenIn this case, since all inversion of the liquid crystal can be achieved, the alternation of the first half field and the second half field is not required. However, if the voltage applied by the liquid crystal is not inverted for a long time, charges may be accumulated between the upper and lower conductive layers due to incomplete discharge, which may affect the erase effect; therefore, the charge stored between the upper and lower conductive layers can be completely discharged by inverting the charge at regular intervals.
As an alternative, the present embodiment provides a method of most saving erase energy, i.e., when the first voltage V 1 And a third voltage V 3 The method meets the following conditions:
；
and the time T for erasing is equal to the erase response time T of the liquid crystal E When the energy consumption is low, the energy consumption can be minimized; wherein the voltage V E The voltage applied to enable the bistable liquid crystal in a certain region to be completely inverted from the planar state to the focal conic state. FIG. 3 shows the energy and voltage required for erasureIt can be seen that when +.>At 1.1V E Nearby, the required energy E reaches a minimum.
The method of the embodiment can realize local erasure with the smallest possible energy and can ensure the effect of local erasure.
Example two
The embodiment particularly discloses an erasure control method of a liquid crystal writing device, which is suitable for a one-key erasure mode; the liquid crystal writing device comprises a first conductive layer, a bistable liquid crystal layer and a second conductive layer; the bistable liquid crystal layer is positioned between the first conductive layer and the second conductive layer, and neither the first conductive layer nor the second conductive layer is divided.
The erasure control method specifically comprises the following steps:
determining an erase onset voltage V for a liquid crystal writing device st ；
Applying a first voltage V to the first conductive layer 1 Applying a third voltage V to the second conductive layer 3 The liquid crystal writing device can be completely erased in an energy-saving mode;
wherein the first voltage V 1 And a third voltage V 3 The method meets the following conditions:
；
；
；
；
r is equivalent alternating current impedance between the upper conductive layer and the lower conductive layer, E is the minimum energy required by liquid crystal inversion, and the minimum energy required by liquid crystal inversion refers to the minimum energy required by all liquid crystal molecules capable of being inverted from a planar state to a focal conic state.
T is the time taken for erasure; t is not less than liquidCrystal erase response time T E The method comprises the steps of carrying out a first treatment on the surface of the Also, T is typically less than 200 milliseconds in order to ensure that no significant delay is seen by the human eye when a partial erase is performed.
Erase response time T of liquid crystal E Refers to: and after the set erasing voltage is applied, the time required for the liquid crystal molecules to be completely overturned from the plane state to the focal conic state is shortened. T (T) E Is related to the applied voltage, liquid crystal formulation, liquid crystal thickness, and insulating layer thickness curing process. It can be appreciated that when the applied voltages are different for different liquid crystals, the erase response time T of the resulting liquid crystals E Will also be different, FIG. 2 shows the erase response time T E With applied voltageIs a schematic diagram of the relationship of (1); t (T) E The specific value of (2) may be measured based on the specific liquid crystal and applied voltage. Such as: when->Greater than or equal to V E At the time T E Typically between a few milliseconds and tens of milliseconds; while->Less than V E At the time T E May reach several hundred milliseconds.
V D The initial voltage is the initial voltage when the liquid crystal state is changed from the focal conic state to the vertical cross-structure state. As already previously analyzed, whenWhen erasure may not be achieved; alternatively, although usable for erasure, erasure is slow and the required energy is high, and energy saving cannot be achieved.
As before, the so-called partial inversion of this embodiment is generally considered to be at least 10% inversion of the liquid crystal; the so-called total inversion is generally considered to be at least 90% inversion of the liquid crystal.
The implementation described in this embodiment writes to liquid crystalComplete erasure of the device, means by proper choice of T andthe erase energy can be controlled to be as small as possible while ensuring that the target erase region is completely erased, while other regions are unaffected.
Further, by rational choice of T andthe value of (2) is such that ∈>When the energy-saving erasure is considered to be realized.
As an alternative, the present embodiment provides a method of most saving erase energy, i.e., when the first voltage V 1 And a third voltage V 3 The method meets the following conditions:
；
and the time T for erasing is equal to the erase response time T of the liquid crystal E When the energy consumption is low, the energy consumption can be minimized; wherein the voltage V E The voltage required to be applied to enable the bistable liquid crystal to flip from the planar state to the focal conic state throughout. FIG. 3 shows the energy and voltage required for erasureIt can be seen that when +.>At 1.1V E Nearby, the required energy E reaches a minimum.
In the present embodiment, whenDuring the erase time T, +.>Every other value is requiredThe set time is reversed, so that complete erasure can be ensured.
Specifically, the negation refers to: applying a voltage difference between the upper conductive layer and the lower conductive layerAs the first half field, the difference between the applied voltages of the upper conductive layer and the lower conductive layer is +.>As the second half field. That is, the upper conductive layer has a higher potential than the lower conductive layer in the upper half field, and the upper conductive layer has a lower potential than the lower conductive layer in the lower half field. The complete erasure of the target erasure area can be achieved by constantly alternating the first half field and the second half field.
Of course, whenIn this case, since all inversion of the liquid crystal can be achieved, the alternation of the first half field and the second half field is not required. However, if the voltage applied by the liquid crystal is not inverted for a long time, charges may be accumulated between the upper and lower conductive layers due to incomplete discharge, which may affect the erase effect; therefore, the charge stored between the upper and lower conductive layers can be completely discharged by inverting the charge at regular intervals.
The method of the embodiment can realize one-key erasure with the smallest possible energy and can ensure the erasure effect.
Example III
In one or more embodiments, a liquid crystal writing apparatus is disclosed that considers erase energy, comprising in particular: the bistable liquid crystal display comprises a first conductive layer, a bistable liquid crystal layer and a second conductive layer which are sequentially arranged, wherein the bistable liquid crystal layer is positioned between the first conductive layer and the second conductive layer, and the two conductive layers are respectively divided into more than two mutually insulated conductive areas.
As a specific example, in connection with fig. 6, the first conductive layer is divided into a plurality of lateral mutually parallel and insulated first conductive areas; the second conductive layer is divided into a plurality of longitudinal second conductive areas which are parallel to each other and insulated; the first conductive region and the second conductive region are spatially perpendicular to each other.
The liquid crystal writing device according to the first embodiment of the present invention is the liquid crystal writing device according to the first embodiment of the present invention, wherein the first conductive layer and the second conductive layer are formed by a liquid crystal layer.
The liquid crystal writing device can be applied to products such as a liquid crystal blackboard, a writing board, a drawing board and the like, and a local erasing function is achieved.
Example IV
In one or more embodiments, a liquid crystal writing apparatus is disclosed that considers erase energy, comprising in particular: the bistable liquid crystal display comprises a first conductive layer, a bistable liquid crystal layer and a second conductive layer which are sequentially arranged, wherein the bistable liquid crystal layer is positioned between the first conductive layer and the second conductive layer, and the two conductive layers are not separated.
The liquid crystal writing device of the embodiment adopts the erasing control method of the second embodiment, and applies set voltages to the first conductive layer and the second conductive layer respectively, so that an electric field can be formed at a position where the first conductive layer and the second conductive layer are spatially overlapped, and one-key erasing is realized.
The liquid crystal writing device of the embodiment can be applied to products such as a liquid crystal blackboard, a writing board, a drawing board and the like, and realizes a one-key erasing function.
The foregoing description is only of the preferred embodiments of the present application and is not intended to limit the same, but rather, various modifications and variations may be made by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims (12)

1. An erasure control method of a liquid crystal writing device, wherein a bistable liquid crystal layer is positioned between a first conductive layer and a second conductive layer, and the two conductive layers are respectively divided into more than two mutually insulated conductive areas; the erasing control method is characterized by comprising the following steps:
book for determining liquid crystalErase initiation voltage V of write device st ；
Applying a first voltage V to a conductive region on a first conductive layer covering a target erase region 1 Applying a second voltage V to other conductive areas on the first conductive layer 2 The method comprises the steps of carrying out a first treatment on the surface of the Applying a third voltage V to the conductive region on the second conductive layer covering the target erase region 3 Applying a fourth voltage V to other conductive areas on the second conductive layer 4 The method comprises the steps of carrying out a first treatment on the surface of the Therefore, the target erasing area can be completely erased in an energy-saving mode, and other areas are not affected;
wherein the first voltage V 1 And a third voltage V 3 The method meets the following conditions:
；
；
；
；
；
r is equivalent alternating current impedance between the upper conductive layer and the lower conductive layer of the target erasing area, E is the minimum value of energy required by liquid crystal inversion of the target erasing area, and T is the time used for erasing; t is not less than the erase response time T of the liquid crystal E ；V D The initial voltage is the initial voltage when the liquid crystal state is changed from the focal conic state to the vertical cross-structure state.
2. The method for controlling the erasure of a liquid crystal writing apparatus according to claim 1, wherein said TAndfurther satisfies:
。
3. the method of erase control of a liquid crystal writing apparatus of claim 1, wherein the second voltage and the fourth voltage satisfy:
。
4. the erasing control method of Liquid Crystal Display (LCD) writing device as claimed in claim 1, wherein the third voltage V 3 For a reference value, i.e. zero potential, then:
。
5. the method for controlling erasure of a liquid crystal writing apparatus according to claim 1, further comprising:
when (when)During the erase response time T +.>The value of (2) is inverted every set time;
wherein the voltage V E The voltage applied to enable the bistable liquid crystal in a certain region to be completely inverted from the planar state to the focal conic state.
6. The method of erasing control of a liquid crystal writing device of claim 1, wherein when the first voltage V 1 And a third voltage V 3 The method meets the following conditions:
；
and the time T for erasing is equal to the erase response time T of the liquid crystal E When the required erasing energy is minimum;
wherein the voltage V E The voltage applied to enable the bistable liquid crystal in a certain region to be completely inverted from the planar state to the focal conic state.
7. An erasure control method of a liquid crystal writing device, wherein a bistable liquid crystal layer is located between a first conductive layer and a second conductive layer, and both conductive layers are not divided, comprising:
determining an erase onset voltage V for a liquid crystal writing device st ；
Applying a first voltage V to the first conductive layer 1 Applying a third voltage V to the second conductive layer 3 The liquid crystal writing device can be completely erased in an energy-saving mode;
wherein the first voltage V 1 And a third voltage V 3 The method meets the following conditions:
；
；
；
；
r is equivalent alternating current impedance between the upper conductive layer and the lower conductive layer, E is the minimum energy value required by liquid crystal inversion, and T is the time for erasing; t is not less than the erase response time T of the liquid crystal E ；V D The initial voltage is the initial voltage when the liquid crystal state is changed from the focal conic state to the vertical cross-structure state.
8. The method for controlling the erasure of a liquid crystal writing apparatus according to claim 7, wherein said T andfurther satisfies:
。
9. the method for controlling erasing of a liquid crystal display writing device as claimed in claim 7, wherein when the first voltage V 1 And a third voltage V 3 The method meets the following conditions:
；
and the time T for erasing is equal to the erase response time T of the liquid crystal E When the required erasing energy is minimum;
wherein the voltage V E The voltage required to be applied to enable the bistable liquid crystal to flip from the planar state to the focal conic state throughout.
10. The method for controlling the erasure of a liquid crystal writing apparatus according to claim 7, wherein whenDuring the erase response time T +.>The value of (2) is inverted every set time;
wherein the voltage V E The voltage required to be applied to enable the bistable liquid crystal to flip from the planar state to the focal conic state throughout.
11. A liquid crystal writing apparatus comprising: the bistable liquid crystal display comprises a first conductive layer, a bistable liquid crystal layer and a second conductive layer which are sequentially arranged, wherein the bistable liquid crystal layer is positioned between the first conductive layer and the second conductive layer, and the two conductive layers are respectively divided into more than two mutually insulated conductive areas; the method for controlling the erasing according to any one of claims 1 to 6 is characterized in that the partial erasing is realized.
12. A liquid crystal writing apparatus comprising: the erasing control method of any one of claims 7 to 10 is adopted to realize the erasing.
CN202311756723.XA 2023-12-20 2023-12-20 Erasing control method and device for liquid crystal writing device Active CN117452729B (en)

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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1220169A (en) * 1967-09-14 1971-01-20 Rca Corp Turn off method and circuit for liquid crystal display element
JP2008134634A (en) * 2007-11-12 2008-06-12 Fujitsu Ltd Display element driving method
US20090231501A1 (en) * 2008-03-13 2009-09-17 Fuji Xerox Co., Ltd. Method for driving liquid crystal device and driving apparatus for the liquid crystal device
CN109597259A (en) * 2019-01-30 2019-04-09 深圳市恒开源电子有限公司 Can selective erase liquid crystal handwriting pad and erasing apparatus
CN110147171A (en) * 2018-06-15 2019-08-20 山东蓝贝思特教装集团股份有限公司 Liquid crystal writing film selective erase voltage generates and control method

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1220169A (en) * 1967-09-14 1971-01-20 Rca Corp Turn off method and circuit for liquid crystal display element
JP2008134634A (en) * 2007-11-12 2008-06-12 Fujitsu Ltd Display element driving method
US20090231501A1 (en) * 2008-03-13 2009-09-17 Fuji Xerox Co., Ltd. Method for driving liquid crystal device and driving apparatus for the liquid crystal device
CN110147171A (en) * 2018-06-15 2019-08-20 山东蓝贝思特教装集团股份有限公司 Liquid crystal writing film selective erase voltage generates and control method
CN109597259A (en) * 2019-01-30 2019-04-09 深圳市恒开源电子有限公司 Can selective erase liquid crystal handwriting pad and erasing apparatus

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