CN113741078A - Liquid crystal writing device and method with adjustable local erasing effect - Google Patents
Liquid crystal writing device and method with adjustable local erasing effect Download PDFInfo
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- CN113741078A CN113741078A CN202110974000.1A CN202110974000A CN113741078A CN 113741078 A CN113741078 A CN 113741078A CN 202110974000 A CN202110974000 A CN 202110974000A CN 113741078 A CN113741078 A CN 113741078A
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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
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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
- G06F3/0412—Digitisers structurally integrated in a display
Abstract
The invention discloses a liquid crystal writing device with adjustable local erasing effect and a method thereof, which relate to the technical field of liquid crystal writing and comprise a writing board and an erasing piece, wherein the erasing piece is provided with a camera shooting unit to obtain a local erasing image and judge whether the erasing effect is achieved, and when the erasing effect is not achieved, the voltage difference between a basal layer and a conductive layer in a set area and the time required by one-time erasing are adjusted, or the voltage difference between the basal layer and the conductive layer, the pre-charging voltage and the discharging frequency, or the voltage difference between the conductive areas of a first conductive layer and a second conductive layer and the time required by one-time erasing are adjusted to achieve the set erasing effect, thereby solving the problems of poor erasing effect, slow erasing speed or mistaken erasing in a non-target area.
Description
Technical Field
The invention relates to the technical field of liquid crystal writing, in particular to a liquid crystal writing device and method with adjustable local erasing effect.
Background
The statements in this section merely provide background information related to the present disclosure and may not necessarily constitute prior art.
When the current liquid crystal writing device erases written contents, the current liquid crystal writing device is limited by a voltage loading mode and a loaded voltage value, when an erasing electric field is formed in an erasing area, if the voltage is too large, the electric field in a neighboring area of the current liquid crystal writing device is influenced and can not be completely zero, so that other conductive areas can be influenced by the erasing voltage and become shallow or disappear while local erasing is realized; if the voltage is too small, the target erasing area may not be completely erased, and when the target erasing area is not completely erased, the target erasing area can only be manually and repeatedly erased, the loaded voltage cannot be automatically adjusted according to the current erasing effect, and the optimal erasing effect cannot be matched.
Disclosure of Invention
In order to solve the problems, the invention provides a liquid crystal writing device with an adjustable local erasing effect and a method thereof.
In order to achieve the purpose, the invention adopts the following technical scheme:
in a first aspect, the present invention provides a liquid crystal writing device with adjustable local erasing effect, comprising: a writing pad and a wiping member; the writing board comprises a main control unit, and a conducting layer, a bistable liquid crystal layer and a substrate layer which are sequentially arranged; the substrate layer is integrated with: the pixel array structure comprises a plurality of pixel units which are arranged in an array shape, wherein each pixel unit is internally provided with a pixel electrode and a thin film field effect transistor (TFT) connected with the pixel electrode;
the erasing piece is provided with a camera unit to obtain a local erasing image and judge whether an erasing effect is achieved, and when the erasing effect is not achieved, the voltage difference between the basal layer and the conductive layer in the set area and the time required by one-time erasing are adjusted to achieve the set erasing effect.
In a second aspect, the present invention provides a liquid crystal writing device with adjustable local erasing effect, which is suitable for a scheme of implementing erasing by illumination, and includes: a writing pad and a wiping member; the writing board comprises a main control unit, and a conducting layer, a bistable liquid crystal layer and a substrate layer which are sequentially arranged; the substrate layer is integrated with: the pixel array structure comprises a plurality of pixel units which are arranged in an array shape, wherein each pixel unit is internally provided with a pixel electrode and a thin film field effect transistor (TFT) connected with the pixel electrode;
the erasing piece is provided with a camera unit to obtain a local erasing image and judge whether an erasing effect is achieved, and when the erasing effect is not achieved, the voltage difference, the pre-charging voltage and the discharging frequency between the basal layer and the conductive layer in the set area are adjusted to achieve the set erasing effect.
In a third aspect, the present invention provides a liquid crystal writing instrument with adjustable local erasing effect, comprising a writing board and an erasing member; the writing board comprises a main control unit, and a first conducting layer, a liquid crystal layer and a second conducting layer which are sequentially arranged; the first conducting layer and the second conducting layer are both divided into two or more conducting areas which are insulated from each other; the conductive areas of the first conductive layer and the second conductive layer form an erasing area together with the liquid crystal layer area corresponding to the overlapped part of the space;
the erasing piece is provided with a camera shooting unit to obtain a local erasing image and judge whether an erasing effect is achieved, and when the erasing effect is not achieved, the voltage difference between the conductive areas of the first conductive layer and the second conductive layer at the set position and the time required by one-time erasing are adjusted to achieve the set erasing effect.
As an alternative embodiment, the adjusting the precharge voltage includes: controlling all or a set part of TFTs on the substrate layer to be in a critical state, and realizing local erasing by utilizing illumination within a set intensity range; and after the local erasing is finished, controlling the voltage difference between the substrate layer and the conductive layer to be within the set voltage value range.
As an alternative embodiment, the erased object image of the action position of the erasing piece collected by the camera unit is acquired, and the last frame of erased object image is controlled and stored for reproduction of the last frame of erased object image.
As an alternative embodiment, the set erasing effect is that the target erasing area is completely erased within a set time and the non-target erasing area is not affected.
As an alternative embodiment, the main control unit is configured to determine the erasure effect.
As an alternative embodiment, the erasing member is provided with a control unit, and the control unit is used for judging the erasing effect.
In a fourth aspect, the present invention provides a partial erasing method using the above liquid crystal writing apparatus, comprising: and when the erasing effect is not achieved, the voltage difference between the basal layer and the conductive layer at the set position and the time required by one-time erasing are adjusted so as to achieve the set erasing effect.
In a fifth aspect, the present invention provides a local erasing method using the above liquid crystal writing device, which is suitable for a scheme of implementing erasing by illumination, and includes: and acquiring a local erasing image of the acting position of the erasing piece, judging whether an erasing effect is achieved or not according to the local erasing image, and adjusting the voltage difference, the pre-charging voltage and the discharging frequency between the basal layer and the conductive layer at the set position to achieve the set erasing effect when the erasing effect is not achieved.
In a sixth aspect, the present invention provides a partial erasing method using the above liquid crystal writing apparatus, comprising: and when the erasing effect is not achieved, the voltage difference between the conductive areas of the first conductive layer and the second conductive layer at the set position and the time required by one-time erasing are adjusted so as to achieve the set erasing effect.
Compared with the prior art, the invention has the beneficial effects that:
according to the liquid crystal writing device and the liquid crystal writing method with the adjustable local erasing effect, the erasing image of the target erasing area is obtained through the camera unit, the local erasing effect is judged through the identification of the erasing image, if the target erasing area is not completely erased or the handwriting of the non-target erasing area becomes light, the voltage difference between the base layer and the conductive layer at the set area and the time required by one-time erasing are adjusted, or the voltage difference between the base layer and the conductive layer, the pre-charging voltage and the discharging frequency are adjusted, or the voltage difference between the conductive areas of the first conductive layer and the second conductive layer and the time required by one-time erasing are adjusted, the problems that the erasing effect is poor, the erasing speed is slow or the non-target area is mistakenly erased are solved, the loaded voltage value is automatically adjusted according to the current erasing effect, and the optimal erasing effect is matched.
According to the liquid crystal writing device and the liquid crystal writing method with the adjustable local erasing effect, when the local erasing effect meets the set requirement, the erasing condition selected at the moment can be maintained, and repeated judgment is not needed.
According to the liquid crystal writing device and the liquid crystal writing method with the adjustable local erasing effect, the image of the erased object is obtained by the camera unit, and the recording of the erased content and the repeated display after the mistaken erasing are realized according to the image of the erased object and the position of the image of the erased object.
Advantages of additional aspects of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.
Drawings
The accompanying drawings, which are incorporated in and constitute a part of this specification, are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification, illustrate exemplary embodiments of the invention and together with the description serve to explain the invention and not to limit the invention.
Fig. 1 is a schematic structural diagram of a liquid crystal writing device with adjustable local erasing effect according to embodiment 1 of the present invention;
FIG. 2 is a schematic diagram of a substrate layer structure of a liquid crystal writing device provided in embodiment 1 of the present invention;
FIG. 3 is a schematic view of an erasing member according to embodiment 1 of the present invention;
fig. 4 is a structural diagram of an equivalent circuit of a TFT provided in embodiment 1 of the present invention;
fig. 5 is a graph showing the turn-on characteristics of a TFT according to embodiment 1 of the present invention;
fig. 6 is a schematic diagram of a two-film structure of a liquid crystal writing device provided in embodiment 3 of the present invention.
The specific implementation mode is as follows:
the invention is further described with reference to the following figures and examples.
It is to be understood that the following detailed description is exemplary and is intended to provide further explanation of the invention as claimed. 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 invention 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 exemplary embodiments according to the invention. As used herein, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise, and it should be understood that the terms "comprises" and "comprising", and any variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.
The embodiments and features of the embodiments of the present invention may be combined with each other without conflict.
Example 1
The present embodiment provides a liquid crystal writing device with adjustable local erasing effect, including: a writing pad and a wiping member; as shown in fig. 1, the writing board includes a main control unit, and a conductive layer, a bistable liquid crystal layer and a substrate layer sequentially disposed; as shown in fig. 2, the substrate layer has integrated thereon: the pixel array structure comprises a plurality of pixel units which are arranged in an array shape, wherein each pixel unit is internally provided with a pixel electrode and a thin film field effect transistor (TFT) connected with the pixel electrode;
the erasing piece is provided with a camera unit to obtain a local erasing image, whether an erasing effect is achieved is judged according to the local erasing image, and when the erasing effect is not achieved, the voltage difference between the basal layer and the conductive layer in the set area and the time required by one-time erasing are adjusted to achieve the set erasing effect.
In this embodiment, the main control unit is configured to determine an erase effect; or the erasing piece is provided with a control unit, and the control unit is used for judging the erasing effect.
Preferably, the camera unit is communicated with the main control unit or the control unit, and the camera unit is used for collecting a local erasing image and an erasing object image in the erasing process of the acting position of the erasing piece and sending the local erasing image and the erasing object image to the main control unit or the control unit through wireless communication;
the main control unit or the control unit determines whether the local erasing effect meets the set requirement according to the size and/or the shape and/or the trace of the erased object in the local erasing image;
the main control unit or the control unit positions the relative position of the erased object on the writing board according to the erased object image, determines the local erased position information, and stores the erased object image and the position information thereof;
the camera shooting unit continuously collects the erased object images and sends the images to the main control unit or the control unit, in the main control unit, the erased object image of the next frame covers the erased object image of the previous frame, and until the erased object image of the last frame is obtained, the main control unit or the control unit erases the action position of the piece and locates the erased object image of the last frame.
In this embodiment, the set erasing effect is that the target erasing area is completely erased within the set time, and the non-target erasing area is not affected;
preferably, the set time is such that the erasing speed matches the erasing member moving speed.
In this embodiment, if the local erasing effect is that the target erasing area is not completely erased and/or the non-target area appears with a visually recognizable writing fading or disappearance, wherein when the voltage difference applied between the substrate layer and the conductive layer corresponding to the erasing area is too large, the non-target erasing area is affected, i.e. erased by mistake, and the visually recognizable writing fading or disappearance appears in the area, even the liquid crystal writing board turns green; when the voltage difference applied between the base layer and the conductive layer corresponding to the erasing area is small, the target erasing area is not completely erased;
therefore, by adjusting the voltage difference between the base layer and the conductive layer in the set area, when the writing in the non-target erasing area is lightened, the voltage difference between the input voltage and the control voltage is reduced, when the target erasing area is not completely erased, the voltage difference between the input voltage and the control voltage is increased, and meanwhile, in the erasing period, the erasing speed is improved, so that the local erasing image acquired by the camera unit meets the set requirement.
In addition, the time required for one-time erasing is also adjusted, and for one erasing period of the target erasing area, if the setting is too long, the erasing of other non-target erasing areas is not effective after the target erasing area is erased, so that the non-target erasing area is affected; or if the setting is too short, the target erasing area is not completely erased, so the time required for one-time erasing needs to meet the erasing effect that the target erasing area is completely erased in the erasing time and the non-target erasing area is not affected.
In this embodiment, the local erasing effect in the local erasing image and the position information of the erased object image may be obtained through algorithms such as image recognition and target positioning, which are not limited herein as long as they can be achieved.
In this embodiment, the erasing member includes a housing, and the image pickup unit may be disposed on an outer side surface of the housing.
The erasing piece comprises a power supply unit, the power supply unit is a battery, a wired charging power supply or a wireless charging power supply, and the power supply unit supplies power to the camera shooting unit.
The erasing piece comprises a wireless communication module, and the wireless communication module is communicated with the main control unit or the control unit.
As shown in fig. 3, the erasing device includes a trigger unit, the trigger unit is a button, a determination mode is performed through the trigger unit to determine the local erasing effect, after the local erasing effect meets the setting requirement, the determination mode is exited, a normal erasing mode is entered, the voltage difference applied between the substrate layer and the conductive layer and the time required for one-time erasing are maintained, and thus the erasing task is continuously performed.
The erasing piece comprises a signal transmitting unit, the signal transmitting unit is started through a trigger unit, and the main control unit or the control unit receives a first signal sent by the signal transmitting unit after the trigger unit triggers and controls a starting judgment mode;
and after the local erasing effect meets the set requirement, the main control unit or the control unit receives a second signal sent by the signal transmitting unit after the trigger unit triggers, and the main control unit or the control unit controls to exit the judgment mode.
In this embodiment, after the voltage difference applied between the base layer and the conductive layer and the time required for one-time erasing are fixed, the image capturing unit still obtains the erased image and sends the erased image to the main control unit or the control unit, and the main control unit stores the erased object image of the last frame, so that when the erasing error occurs, the main control unit controls and displays the stored erased object image of the last frame according to the position information of the erased object image of the last frame.
In this embodiment, for the double-layer display content, for example, in the case of a handwritten annotation existing on a fixed writing, the main control unit pre-stores the fixed writing and the position information thereof, and after performing local erasing, performs repeated display on the stored fixed writing, so as to realize that only one layer of the double-layer display content is erased.
The method for realizing the reproduction of the erased object comprises the following steps: the main control unit controls the conduction and the input voltage of the TFT according to the display position of the repeated display content, and applies a first voltage to the pixel unit covering the display position; applying a second voltage to the conductive layer; the electric field formed by the first voltage and the second voltage at the position where the pixel unit and the conducting layer are overlapped in space can realize the display of the repeated display content.
In this embodiment, the bistable liquid crystal layer is a bistable cholesteric liquid crystal capable of writing by pressure. The liquid crystal can change the liquid crystal state when receiving pressure, and realizes pressure writing display; the liquid crystal state is changed under the action of a set first electric field, so that the erasing is realized; the specific value of the first electric field is determined according to the property of the bistable cholesteric liquid crystal and the thickness of the liquid crystal.
In this embodiment, the liquid crystal writing device is a liquid crystal writing device in the prior application CN112748600A of the applicant, and the principle of local erasing is as follows: based on the erasing position in each row, by controlling the conduction and input voltages of the TFTs set in each row, the set voltages are input for the corresponding pixel electrodes so that the pixel electrodes and the conductive layers form a set electric field at the position where the pixel electrodes and the conductive layers are spatially overlapped, and local erasing is realized.
The specific voltage application process comprises: controlling all TFTs to be conducted, applying a second voltage to all pixel units of the base layer, and applying a second voltage to the conductive layer; keeping the conductive layer applied with the second voltage, keeping the TFTs of the pixel units covering the local erasing area in each row needing to be erased switched on, applying the first voltage to the pixel units, and applying the second voltage to the rest pixel units in the row; the TFT is not turned on for non-erased rows.
As shown in fig. 4, the equivalent circuit structure of the TFT includes a gate (control voltage input terminal) connected to the first conductive line, a source (input voltage input terminal) connected to the second conductive line, and a drain (output terminal) connected to the corresponding pixel electrode.
Preferably, electrode wires are respectively led out of the base layer and the conductive layer; is used for connecting a voltage driving circuit which can provide required voltage.
Preferably, a positioning circuit is further integrated on the substrate layer for positioning the erasing piece so as to realize the position positioning during partial erasing or the position positioning of the handwriting or other positioning functions.
It can be understood that the positioning circuit can be implemented by electromagnetic positioning, capacitive positioning, infrared positioning, ultrasonic positioning or image positioning, which are positioning methods already disclosed in the prior art, and the specific implementation process is not described in detail.
As shown in fig. 5, the on characteristic curve of the TFT is plotted with voltage on the abscissa and current on the ordinate; applying a voltage V to the gate GGoffWhen the TFT cut-off current is minimum, a voltage V is applied to the gate GonWhen this occurs, the TFT approaches the maximum on current.
The voltage control method for realizing the local erasing is as follows:
(1) and applying a second voltage to each pixel unit of the base layer and the conductive layer respectively, wherein the voltage difference between the conductive layer and each pixel unit of the base layer is zero.
Specifically, the TFT gate of each pixel unit of the substrate layer is provided with a turn-on voltage V through a first lead wireonA second voltage is provided for the TFT source electrode of each pixel unit of the substrate layer through a second conducting wire; in this way, the TFT of each pixel cell is turned on, so that the voltage applied to each pixel electrode is the second voltage, and simultaneously, the voltage across each storage capacitor C1 is precharged to the second voltage.
And the voltage applied on the conductive layer is also the second voltage, so that the electric field of each pixel unit of the whole substrate layer and the corresponding area of the conductive layer are all zero, and local erasing can not occur at the moment.
(2) In the first half period of voltage application, a first voltage is applied to the pixel electrodes covering the local erasing area in each row of pixel units on the substrate layer, the rest pixel electrodes still maintain a second voltage, and the voltage applied to the conductive layer also maintains the second voltage; at this time, the voltage difference between the pixel electrode and the conductive layer in the row, which only covers the local erase region, is | the first voltage-the second voltage |, the difference reaches the erase electric field, and the voltage difference of the rest regions is still zero, so that the erase of the local erase region can be realized.
Specifically, the first wire for connecting the pixel units of a certain row is provided with a conducting voltage VonSo as to provide the TFT gates of all the pixel units of the row with turn-on voltage through the first lead; the TFTs of all the pixel units connected with the first lead are conducted; providing voltage V for other rows of pixel units through the remaining first conductorGoffSo that the other pixel units are not conductive.
A first voltage is supplied to the second conductor line to which the TFT sources of the pixel cells in the row overlying the local erase region are connected, and a second voltage is supplied to the second conductor line to which the TFT sources of the remaining pixel cells in the row are connected.
At this time, for the pixel unit covering the local erasing area, the turn-on voltage of the TFT is a first voltage, the electric field formed between the area and the corresponding area of the conductive layer is | the first voltage — a second voltage |, and the difference reaches the erasing electric field; for the rest pixel units in the row, the turn-on voltage of the TFT is a second voltage, and the electric fields formed between the areas and the corresponding areas of the conducting layer are all zero;
for the non-conductive pixel units in other rows, because the TFT is not conductive, the voltage of the previously precharged energy storage capacitor C1 cannot be discharged, so that the voltages corresponding to the pixel units are equal to the voltage of the energy storage capacitor, which are all the second voltages, and the electric fields formed between the areas and the corresponding areas of the conductive layer are also all zero.
Therefore, only the writing of the partially erased area is erased, and the writing of the rest area is not affected.
(3) In the second half period of voltage application, a third voltage is applied to the pixel units covering the local erasing area in each row of pixel units on the substrate layer, the rest pixel units still maintain the second voltage, and the voltage applied to the conductive layer also maintains the second voltage; at this time, the voltage difference between the pixel unit and the conductive layer, which covers only the local erase region, is | the third voltage-the second voltage |, the first voltage-the second voltage |, the difference reaches the erase electric field, and the voltage difference of the remaining region is still zero, so that the erase of the local erase region can be realized.
The specific voltage control implementation is the same as the previous half cycle, and is not described again.
The erasing voltage is the voltage required for completely erasing the handwriting, and the erasing electric field is the electric field formed by the erasing voltage between the corresponding areas of the two conductive layers;
it is understood that the first half period and the second half period can be interchanged, and any half period can be used to realize erasing.
Example 2
The present embodiment provides a liquid crystal writing device with adjustable local erasing effect, including: a writing pad and a wiping member; the writing board comprises a main control unit, and a conducting layer, a bistable liquid crystal layer and a substrate layer which are sequentially arranged; the substrate layer is integrated with: the pixel array structure comprises a plurality of pixel units which are arranged in an array shape, wherein each pixel unit is internally provided with a pixel electrode and a thin film field effect transistor (TFT) connected with the pixel electrode;
the erasing piece is provided with a camera unit to obtain a local erasing image and judge whether an erasing effect is achieved, and when the erasing effect is not achieved, the voltage difference, the pre-charging voltage and the discharging frequency between the basal layer and the conductive layer in the set area are adjusted to achieve the set erasing effect.
In this embodiment, the main control unit is configured to determine an erase effect; or the erasing piece is provided with a control unit, and the control unit is used for judging the erasing effect.
The communication between the main control unit or the control unit and the camera unit, the functions and the repeated display of the main control unit or the control unit are the same as those of embodiment 1, and are not described herein again.
In the embodiment, the influence of illumination on the on-state characteristics of the TFT is utilized, and the local erasing of the liquid crystal writing device is realized by utilizing the illumination; the liquid crystal writing device adopts a liquid crystal writing device of the prior application CN112684618B, and the local erasing principle is as follows: energizing the grid electrodes and the source electrodes of all the TFTs on the substrate layer, and respectively applying a first voltage and a second voltage which are set so that all the TFTs are in a critical state; simultaneously applying a set third voltage to the conductive layer; when a certain area on the liquid crystal writing device receives illumination with set intensity, the TFT of the corresponding erasing unit on the substrate layer corresponding to the area is conducted, and therefore second voltage is applied to the corresponding erasing electrode; and the voltage difference | second voltage-third voltage | between these erasing electrodes and conducting layer, this voltage difference can reach the local erasing voltage of liquid crystal, thus realize the local erasure to the illumination irradiation area.
The power-up process is as follows: applying set voltages to the gate and the source of all or set partial TFTs on the substrate layer respectively; the voltage can enable the TFT to be in a cut-off state when the TFT does not receive illumination within a set intensity range; and after receiving illumination within a set intensity range, the TFT can be conducted, and an erasing electric field can be formed between the voltage loaded on the erasing electrode connected with the conducting TFT and the conducting layer, so that local erasing is realized.
The critical state of a TFT refers to: applying a set voltage to the conductive layer, and applying a set control voltage and an input voltage to the TFT electrode respectively; namely, a set control voltage is applied to the grid electrode of the TFT, a set input voltage is applied to the source electrode of the TFT, and the TFT is in a cut-off state when the TFT is not irradiated by light with set light intensity; when the TFT receives light irradiation with a set light intensity, the passing current of the TFT reaches a set value, and a set voltage is applied to the erasing electrode.
The discharge process between the substrate layer and the conductive layer is as follows: applying set voltages to the gate and the source of all or set partial TFTs on the substrate layer respectively; the voltage can turn on the TFT and cause a voltage difference formed between the base layer and the conductive layer to be zero or less than a voltage required for erasing the liquid crystal.
The TFT is turned on to provide a set voltage for the corresponding erasing electrode, so that an electric field which is larger than or equal to a liquid crystal erasing electric field is formed at the position where the erasing electrode and the conducting layer are overlapped in space, local erasing is caused, the TFT which is not irradiated by the light with set intensity is still in an off state, and the display of the corresponding area is not influenced.
In this embodiment, the set erasing effect is that the target erasing area is completely erased within the set time, and the non-target erasing area is not affected; the voltage difference, the pre-charging voltage and the discharging frequency between the basal layer and the conductive layer at the set area are adjusted, so that the target erasing area is completely erased and the non-target erasing area is not affected.
The precharge voltage is adjusted to: controlling all or a set part of TFTs on the substrate layer to be in a critical state, and realizing local erasing by utilizing illumination within a set intensity range; after the partial erasing is finished, the voltage difference between the substrate layer and the conductive layer is controlled to be within a set voltage value range. By setting the precharge voltage, the time required from the conduction of the TFT light to the voltage difference between the underlying layer and the conductive layer to the erase voltage of the liquid crystal is shortened, and the speed of local erasing is increased.
The set voltage value range is determined by the erase voltage of the liquid crystal, the capacitance between the base layer and the conductive layer, and the photoconductive current; the setting can be performed according to actual needs. The larger the light transmission area of the light transmission opening of the TFT, the smaller the set upper voltage limit of the voltage range, and the smaller the light transmission area of the light transmission opening of the TFT, the larger the set upper voltage limit of the voltage range.
And judging whether the discharge time interval of the writing board meets the set requirement or not according to the local erasing effect, if the target erasing area is not completely erased, prolonging the discharge time interval of the writing board, and otherwise, if the handwriting of the non-target erasing area is lightened, shortening the discharge time interval of the writing board.
In the present embodiment, when the erasing effect is achieved, the voltage difference, the precharge voltage, and the discharge frequency applied between the base layer and the conductive layer are maintained.
In this embodiment, the erasing member further includes: the illumination unit is used for providing a light source with set illumination intensity; the trigger unit is also used for triggering the illumination unit to emit light source when receiving the set trigger signal or meeting the set trigger condition.
The rest of the structure of the erasing part is the same as that of embodiment 1, and details are not described here.
Example 3
The embodiment provides a liquid crystal writing device with adjustable local erasing effect, which comprises a writing board and an erasing piece; the writing board comprises a main control unit, and a first conducting layer, a liquid crystal layer and a second conducting layer which are sequentially arranged; as shown in fig. 6, the first conductive layer and the second conductive layer are each divided into two or more conductive regions insulated from each other; the conductive areas of the first conductive layer and the second conductive layer form an erasing area together with the liquid crystal layer area corresponding to the overlapped part of the space;
the erasing piece is provided with a camera shooting unit to obtain a local erasing image and judge whether an erasing effect is achieved, and when the erasing effect is not achieved, the voltage difference between the conductive areas of the first conductive layer and the second conductive layer at the set position and the time required by one-time erasing are adjusted to achieve the set erasing effect.
In this embodiment, the main control unit is configured to determine an erase effect; or the erasing piece is provided with a control unit, and the control unit is used for judging the erasing effect.
The communication between the main control unit or the control unit and the camera unit, the functions implemented by the main control unit or the control unit, the adjustment of the erasing effect, the structure of the erasing part, and the like are the same as those in embodiment 1, and are not described herein again.
In this embodiment, the liquid crystal writing device of the prior application CN108563049A is adopted as the liquid crystal writing device, and the principle of local erasing is as follows: electrically connecting each conductive area on the first conductive layer with a voltage applying device through an electrode and a corresponding lead so as to apply voltage to each conductive area; electrically connecting each conductive area on the second conductive layer with a voltage applying device through an electrode and a corresponding lead so as to apply voltage to the second conductive layer; and applying voltage to each conductive area on the first conductive layer and the second conductive layer respectively, forming superposition of electric fields in each erasing area respectively, and realizing local erasing by using different voltage differences formed in each erasing area.
In this embodiment, when the erasing effect is achieved, the voltage difference applied between the conductive regions of the first conductive layer and the second conductive layer and the time required for one erasing are maintained.
Example 4
On the basis of the liquid crystal writing device with adjustable local erasing effect disclosed in embodiments 1 to 3, specific application products of the liquid crystal writing device are disclosed, such as:
the liquid crystal writing device or the local erasing method of the invention is applied to a writing board, a drawing board or a blackboard to realize the local erasing function or the display function or other functions disclosed above.
Specifically, the liquid crystal writing device according to the embodiment of the present invention may be applied to a light energy writing board, a light energy liquid crystal writing board, a light energy large liquid crystal writing blackboard, a light energy dust-free writing board, a light energy portable blackboard, an electronic drawing board, an LCD electronic writing board, an electronic notepad, a doodle board, a child writing board, a child doodle drawing board, an eraser function sketch board, a liquid crystal electronic drawing board, a color liquid crystal writing board, or other related products known to those skilled in the art.
Although the embodiments of the present invention have been described with reference to the accompanying drawings, it is not intended to limit the scope of the present invention, and it should be understood by those skilled in the art that various modifications and variations can be made without inventive efforts by those skilled in the art based on the technical solution of the present invention.
Claims (10)
1. A liquid crystal writing instrument with adjustable local erasure effect, comprising: a writing pad and a wiping member; the writing board comprises a main control unit, and a conducting layer, a bistable liquid crystal layer and a substrate layer which are sequentially arranged; the substrate layer is integrated with: the pixel array structure comprises a plurality of pixel units which are arranged in an array shape, wherein each pixel unit is internally provided with a pixel electrode and a thin film field effect transistor (TFT) connected with the pixel electrode; it is characterized in that the preparation method is characterized in that,
the erasing piece is provided with a camera unit to obtain a local erasing image and judge whether an erasing effect is achieved, and when the erasing effect is not achieved, the voltage difference between the basal layer and the conductive layer in the set area and the time required by one-time erasing are adjusted to achieve the set erasing effect.
2. A liquid crystal writing instrument with adjustable local erasure effect, comprising: a writing pad and a wiping member; the writing board comprises a main control unit, and a conducting layer, a bistable liquid crystal layer and a substrate layer which are sequentially arranged; the substrate layer is integrated with: the pixel array structure comprises a plurality of pixel units which are arranged in an array shape, wherein each pixel unit is internally provided with a pixel electrode and a thin film field effect transistor (TFT) connected with the pixel electrode; it is characterized in that the preparation method is characterized in that,
the erasing piece is provided with a camera unit to obtain a local erasing image and judge whether an erasing effect is achieved, and when the erasing effect is not achieved, the voltage difference, the pre-charging voltage and the discharging frequency between the basal layer and the conductive layer in the set area are adjusted to achieve the set erasing effect.
3. The liquid crystal writing apparatus with adjustable partial erasing effect as claimed in claim 2, wherein said adjusting the precharge voltage comprises: controlling all or a set part of TFTs on the substrate layer to be in a critical state, and realizing local erasing by utilizing illumination within a set intensity range; and after the local erasing is finished, controlling the voltage difference between the substrate layer and the conductive layer to be within the set voltage value range.
4. The liquid crystal writing apparatus with adjustable local erasing effect as claimed in claim 1 or 2, wherein the erasing object image of the action position of the erasing member collected by the camera unit is acquired, and the erasing object image of the last frame is controlled and stored for reproduction of the erasing object image of the last frame.
5. A liquid crystal writing device with adjustable local erasing effect comprises a writing board and an erasing piece; the writing board comprises a main control unit, and a first conducting layer, a liquid crystal layer and a second conducting layer which are sequentially arranged; the first conducting layer and the second conducting layer are both divided into two or more conducting areas which are insulated from each other; the conductive areas of the first conductive layer and the second conductive layer form an erasing area together with the liquid crystal layer area corresponding to the overlapped part of the space; it is characterized in that the preparation method is characterized in that,
the erasing piece is provided with a camera shooting unit to obtain a local erasing image and judge whether an erasing effect is achieved, and when the erasing effect is not achieved, the voltage difference between the conductive areas of the first conductive layer and the second conductive layer at the set position and the time required by one-time erasing are adjusted to achieve the set erasing effect.
6. The liquid crystal writing apparatus with adjustable local erasing effect as claimed in claim 1, 2 or 5, wherein the set erasing effect is that the target erasing area is completely erased in a set time and the non-target erasing area is not affected.
7. The liquid crystal writing apparatus with adjustable local erasing effect as claimed in claim 1, 2 or 5, wherein said main control unit is used for judging the erasing effect.
8. A partial erasing method using the liquid crystal writing apparatus of claim 1, comprising: and when the erasing effect is not achieved, the voltage difference between the basal layer and the conductive layer at the set position and the time required by one-time erasing are adjusted so as to achieve the set erasing effect.
9. A partial erasing method using the liquid crystal writing apparatus of claim 2, comprising: and acquiring a local erasing image of the acting position of the erasing piece, judging whether an erasing effect is achieved or not according to the local erasing image, and adjusting the voltage difference, the pre-charging voltage and the discharging frequency between the basal layer and the conductive layer at the set position to achieve the set erasing effect when the erasing effect is not achieved.
10. A partial erasing method using the liquid crystal writing apparatus of claim 5, comprising: and when the erasing effect is not achieved, the voltage difference between the conductive areas of the first conductive layer and the second conductive layer at the set position and the time required by one-time erasing are adjusted so as to achieve the set erasing effect.
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