CN113419388B - Liquid crystal writing device and method adaptive to ambient light - Google Patents
Liquid crystal writing device and method adaptive to ambient light Download PDFInfo
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- CN113419388B CN113419388B CN202110964616.0A CN202110964616A CN113419388B CN 113419388 B CN113419388 B CN 113419388B CN 202110964616 A CN202110964616 A CN 202110964616A CN 113419388 B CN113419388 B CN 113419388B
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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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- 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
- G02F1/13718—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 a change of the texture state of a cholesteric liquid crystal
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Abstract
The invention provides a liquid crystal writing device and a method adaptive to ambient light, wherein the liquid crystal writing device controls a discharge time interval between a substrate layer and a conductive layer according to ambient light intensity and illuminance of a light erasing piece, so that the difference value between the time interval from power-on to erasing starting voltage and the time interval from power-on to discharge in an erasing area, which are caused by the ambient light, in a non-erasing area is larger than a preset amount; the light erasing piece adjusts the illumination according to the ambient light intensity, so that the illumination of the light erasing piece is greater than the ambient light intensity, and the illumination of the light erasing piece is a preset multiple of the ambient light intensity; the invention adjusts the illumination of the optical erasing piece according to the intensity of the ambient light in real time, and reduces the power consumption of the optical erasing piece on the basis of ensuring the optical erasing effect; the discharge frequency between the basal layer and the conducting layer is controlled according to the illumination of the optical erasing piece and the intensity of the ambient light, so that the problem of fading of the handwriting of a non-target erasing area caused by strong ambient light is effectively avoided.
Description
Technical Field
The invention relates to the technical field of liquid crystal writing, in particular to a liquid crystal writing device and method adaptive to ambient light.
Background
The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
The liquid crystal writing board or electronic paper on the market at present has the working principle that the bistable characteristic of liquid crystal is utilized to display and/or erase the writing content on the liquid crystal writing board. Taking cholesteric liquid crystal as an example, writing pressure tracks of the writing pen are recorded by changing the liquid crystal state at the pen point through pressure acting on the liquid crystal writing board, and then corresponding writing contents are displayed; the cholesteric liquid crystal structure is changed by applying an electric field, so that the writing track on the liquid crystal writing board disappears to realize erasing.
Because a semiconductor channel of a thin film transistor (hereinafter referred to as TFT) can form a photon-generated carrier, namely an electron-hole pair, under the condition of illumination, for the N-channel TFT, electrons move towards a high potential direction, and holes move towards a low potential direction, so that hole leakage current is formed, and the influence of the photon-generated carrier on the leakage current of the TFT device is very obvious; when light is irradiated, the on/off current of the TFT is increased compared with that in the absence of light, and the threshold voltage is also changed correspondingly.
Based on the above phenomenon, chinese patent CN112684618A discloses a technical scheme for implementing local erasing on a liquid crystal writing device by using the light sensitivity of a TFT, which does not need to provide a positioning circuit and a driving circuit, thereby simplifying the circuit structure of the product and improving the reliability of the product; however, the above-mentioned scheme is easily interfered by ambient light, and after the liquid crystal writing device is powered on, the ambient light irradiates for a preset time to make the voltage difference between the pixel electrode and the conductive layer equal to or greater than the erasing start voltage, thereby easily causing the handwriting in the non-target erasing area to fade; moreover, the light intensity of the light erasing part in the prior art is fixed, and the light intensity cannot be adjusted in a self-adaptive manner according to the intensity of the ambient light, so that the power consumption of the light erasing part is larger.
Disclosure of Invention
In order to solve the defects of the prior art, the invention provides a liquid crystal writing device and a method of self-adaptive ambient light, which control the discharge frequency between a basal layer and a conductive layer according to the illumination of an optical erasing piece and the intensity of ambient light, and effectively avoid the problem of writing fading of a non-target erasing area caused by strong ambient light; the illuminance of the optical erasing piece is adjusted in real time according to the intensity of the ambient light, and the power consumption of the optical erasing piece is reduced on the basis of ensuring the optical erasing effect.
In order to achieve the above object, according to a first aspect of the present invention, there is provided an ambient light adaptive liquid crystal writing device, including a writing board and an optical erasing element, where the writing board includes a conductive layer, a bistable liquid crystal layer and a substrate layer, which are sequentially disposed, the substrate layer is integrated with a main control unit and a plurality of erasing units arranged in an array, each erasing unit is provided with a pixel electrode and a TFT connected to the pixel electrode, and the liquid crystal writing device further includes an ambient light detecting element, and the ambient light detecting element is in wireless or wired communication with the main control unit.
Further, the ambient light detection element is located on the optical erasing member.
Further, the optical erasing piece comprises a power supply unit, and the power supply unit is a battery, a wired charging power supply or a wireless charging power supply.
According to a second aspect of the present invention, there is provided a partial erasing method using the liquid crystal writing apparatus of the first aspect, comprising the processes of:
and controlling the discharge time interval between the substrate layer and the conductive layer according to the intensity of ambient light and the illuminance of the optical erasing piece, so that the difference between the time interval from power-on to erasing starting voltage of the non-erasing area caused by the ambient light and the time interval from power-on to discharging of the erasing area is larger than a preset amount.
Further, the preset amount is determined according to a relationship between a TFT photocurrent and illumination.
Furthermore, the illuminance of the optical erasing piece is adjusted according to the intensity of the ambient light, so that the illuminance of the optical erasing piece is greater than the intensity of the ambient light, and the illuminance of the optical erasing piece is a preset multiple of the intensity of the ambient light.
Furthermore, the predetermined multiple is determined according to the relationship between the TFT photocurrent and the illumination, and the predetermined multiple is greater than or equal to 2.
According to a third aspect of the present invention, there is provided a bistable liquid crystal writing tablet comprising the liquid crystal writing device of the first aspect of the present invention; alternatively, the local erase method according to the second aspect of the present invention is used.
According to a fourth aspect of the present invention, there is provided a bistable liquid crystal blackboard comprising the liquid crystal writing device of the first aspect of the present invention; alternatively, the local erase method according to the second aspect of the present invention is used.
According to a fifth aspect of the present invention, there is provided a bistable liquid crystal drawing board comprising the liquid crystal writing device of the first aspect of the present invention; alternatively, the local erase method according to the second aspect of the present invention is used.
Compared with the prior art, the invention has the beneficial effects that:
1. the invention controls the discharge time interval between the substrate layer and the conductive layer according to the ambient light intensity and the illumination of the optical erasing piece, so that the difference value between the time interval from power-up to erasing starting voltage in the non-erasing area caused by the ambient light and the time interval from power-up to discharging in the erasing area is larger than the preset amount.
2. The illuminance of the optical erasing piece is adjusted according to the intensity of the ambient light, so that the illuminance of the optical erasing piece is greater than the intensity of the ambient light, the illuminance of the optical erasing piece is a preset multiple of the intensity of the ambient light, when the ambient light is strong, the illuminance of the optical erasing piece is enhanced, the optical erasing piece can rapidly realize local erasing, and the influence of the strong ambient light on a non-erasing area is avoided; when the ambient light is weak, the illuminance of the optical erasing piece is reduced, the electric quantity of the optical erasing piece is effectively saved, and the single charging service time of the optical erasing piece is prolonged.
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 an ambient light adaptive liquid crystal writing device disclosed in embodiment 1 of the present invention.
Fig. 2 is a schematic structural diagram of a substrate layer of the ambient light adaptive liquid crystal writing device disclosed in embodiment 1 of the present invention.
Fig. 3 is a first TFT connection diagram disclosed in embodiment 1 of the present invention.
Fig. 4 is a second schematic connection diagram of a TFT disclosed in embodiment 1 of the present invention.
Fig. 5 is a schematic structural diagram of the optical erasing member disclosed in embodiment 1 of the present invention.
Wherein, 1, a shell; 2. a battery compartment; 3. a lamp bead; 4. a circuit board; 5. a visor; 6. a conductive ring; 7. an infrared detection unit; 8. a convex lens; 9. wool felt; 10. a magnet group; 11. an ambient light detection element.
Detailed Description
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, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.
The embodiments and features of the embodiments of the present invention may be combined with each other without conflict.
Example 1:
embodiment 1 of the present invention provides an ambient light adaptive liquid crystal writing apparatus, including: the liquid crystal display panel comprises a writing board and an optical erasing piece, wherein the writing board is provided with a conductive layer, a bistable liquid crystal layer and a substrate layer in sequence, as shown in figure 1, a main control unit and a plurality of erasing units which are arranged in an array mode are integrated on the substrate layer, and each erasing unit is internally provided with a pixel electrode and a thin film field effect transistor (TFT) connected with the pixel electrode;
the liquid crystal writing device further comprises an ambient light detection element, and the ambient light detection element is in wireless or wired communication with the main control unit.
In this embodiment, the ambient light detection element is located on the optical erasing member, and it is understood that in other embodiments, the ambient light detection element may also be located on the frame of the writing board or on a wall beside the writing board.
The main control unit controls the discharge time interval between the substrate layer and the conductive layer according to the ambient light intensity and the illuminance of the optical erasing piece, so that the difference value between the time interval from power-on to erasing starting voltage caused by the ambient light in the non-erasing area and the time interval from power-on to discharging in the erasing area is larger than a preset amount, and the non-erasing area cannot become thin due to the influence of the ambient light; when the ambient light intensity is stronger, the time interval from power-up to discharge of the erasing area is shortened, the problem of fading of the handwriting of a non-target erasing area caused by stronger ambient light is effectively avoided, when the ambient light intensity is weaker, the time interval from power-up to discharge of the erasing area is prolonged, in one erasing period, the erasing time ratio is improved, and the erasing speed is improved.
The preset amount can ensure that under the condition that the erasing area of the blackboard eraser is completely erased, the non-erasing area does not generate visual character fading caused by the irradiation of ambient light, and the preset amount is determined by the relationship between the TFT photocurrent and the illumination intensity.
Light induced current of the thin film field effect transistor TFT:
I=f(Window size, ion concentration, storage capacitance, light intensity)
Under the condition that the window size, the ion concentration and the storage capacitor are fixed, the stronger the light intensity received by the thin film field effect transistor TFT is, the larger the light induced current is, the faster the potential of the drain electrode is increased, and the potential between the pixel electrode and the conducting layer can reach the erasing starting voltage more quickly because the pixel electrode and the drain electrode are equipotential.
According to the corresponding relation between the received light intensity and the light induced current of the TFT, the potential of the conductive layer is assumed to be V1The drain potential to reach the erase start voltage is V2When the intensity of the ambient light is A1When the light induced current of the corresponding TFT is I1Based on the illumination induced current I1So that the drain potential reaches V2Time of (a) is T1；
When the light intensity of the light erasing member is A2When the light induced current of the corresponding TFT is I2Based on the illumination induced current I2So that the drain potential reaches V2Time of (a) is T2；
In this example, T1-T2≥TThreshold value，TThreshold valueThe constant is set, and the threshold value of the time interval is set, so that when the ambient light intensity is higher, the discharge time interval of the liquid crystal writing device is shortened, and the non-erasing area is prevented from being faded due to the influence of the ambient light;
when the ambient light intensity is smaller, the discharge time interval of the liquid crystal writing device can be prolonged, and the erasing time is prolonged, and in an erasing period, the erasing time ratio is improved, so that the erasing speed is improved, for example: before the ambient light intensity is weakened, the corresponding erasing time is 10ms, the corresponding discharging time is 5ms, and the erasing time accounts for 67.7 percent; after the ambient light intensity is weakened, the corresponding erasing time is prolonged to 300ms, the discharging time is 5ms, the erasing time ratio is 98.3%, and the erasing time ratio is improved.
In this embodiment, the optical erasing member includes an illumination unit;
an illumination unit configured to: adjusting the illumination according to the ambient light intensity to enable the illumination of the optical erasing piece to be larger than the ambient light intensity, wherein the illumination of the optical erasing piece is a preset multiple of the ambient light intensity; when the ambient light is weak, the illuminance of the optical erasing piece is reduced, the electric quantity of the optical erasing piece is effectively saved, and the single charging service time of the optical erasing piece is prolonged.
Optionally, the preset multiple is determined according to a relationship between a TFT photocurrent and an illuminance, preferably, in this embodiment, the preset multiple is selected to be 4 times, that is, the illuminance of the optical erasing element is 4 times of the ambient light intensity, it can be understood that in some other embodiments, the preset multiple may also be 2.5 times, 3 times, 5 times, or other integers or non-integer multiples greater than or equal to 2, and those skilled in the art may select the preset multiple according to a specific working condition, which is not described herein again.
In this embodiment, the specific local erase strategy is as follows: when receiving an electrifying signal sent by the optical erasing piece, the thin film field effect transistor TFT is configured to be in a critical cut-off state, so that the thin film field effect transistor TFT is turned on after receiving illumination with set intensity, and set voltage is input to the corresponding pixel electrode, so that an erasing electric field is formed at the position where the pixel electrode and the conducting layer are overlapped in space, and local erasing is realized.
The powering up is specifically as follows:
applying set voltages to the gate and the source of all or a set part of TFTs on the substrate layer of the liquid crystal writing device 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; the TFT can be conducted after receiving illumination within a set intensity range, and an erasing electric field can be formed between a voltage loaded on a pixel electrode connected with the TFT and the conducting layer, so that local erasing is realized;
the critical cutoff state specifically includes:
applying a set voltage to the conductive layer, and applying a set control voltage and an input voltage to the TFT electrode respectively; when receiving illumination with set illumination intensity, the TFT is conducted; when the TFT is not irradiated by the light with the set light intensity, the TFT is in a cut-off state;
the discharge between the substrate layer and the conductive layer is specifically as follows:
applying set voltages to the gate and the source of all or a set part of TFTs on the substrate layer of the liquid crystal writing device 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.
In this embodiment, before discharging, the voltage difference between the pixel electrode and the conductive layer caused by the ambient light is always smaller than the erase start voltage, and the difference between the erase start voltage and the voltage difference between the pixel electrode and the conductive layer caused by the ambient light can be set according to a specific working condition, which is not described herein again.
In this embodiment, the TFT can be turned on by applying a predetermined voltage to the TFT, and the TFT can be turned on by receiving illumination of a predetermined intensity when the TFT is in the critical off state.
The critical off state of the TFT means: applying a set control voltage to a gate electrode of the TFT, applying a set input voltage to a source electrode of the TFT, and turning off the TFT when the TFT is not irradiated by light with a set light intensity; when the light irradiation with the set light intensity is received, the passing current of the TFT reaches a set value, and a set voltage is applied to the pixel electrode.
The TFT is turned on to provide a set voltage for the corresponding pixel 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 pixel 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 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.
When the TFT is in the critical off state, the voltages applied to the gate and the source are determined by combining the process characteristics of the TFT itself and the applied light intensity range, and those skilled in the art can select the voltages by experiments according to the actual requirements, and the applied light intensity range can also be selected according to the design requirements.
The light source for setting the illumination intensity (illumination intensity refers to energy per unit area) in the present embodiment may be a visible light source, or may be an invisible light source such as infrared or ultraviolet light.
When local erasing is carried out, a set first voltage and a set second voltage are respectively applied to the grid electrodes and the source electrodes of all the TFTs on the substrate layer, so that all the TFTs are in a critical cut-off 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 second voltage is applied to the corresponding pixel electrode; and the voltage difference | second voltage-third voltage | between these pixel 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.
Of course, if necessary, a voltage may be applied to only a part of the set TFTs to be in a critical off state; in this case, the partial erasing can be performed only by applying light to the region covered by the part of the TFT, and the part other than the region is not in the critical off state because the TFT is not in the critical off state, and therefore, the erasing is not performed even when the light irradiation of the set intensity is received.
In this embodiment, the erasing voltage is a voltage required to completely erase the written handwriting, and the erasing electric field is an electric field formed by the erasing voltage between corresponding areas of the substrate layer and the conductive layer.
In this embodiment, the gates of the TFTs of each erase unit on the substrate layer are divided into one or more groups, the same or similar voltages are applied between the groups, the sources of the TFTs are also divided into one or more groups, the same or similar voltages are applied between the groups, and the voltage application circuit is similar to a one-key erase circuit structure.
Therefore, in a specific implementation mode, the gates of all the TFTs on the substrate layer can be connected to the same wire, or can be connected to different wires through outgoing wires, the wires can be connected in parallel to supply power, or the wires can be grouped to supply power respectively; similarly, the sources of all the TFTs on the substrate layer may be connected to the same wire, or may be connected to different wires through the outgoing line; the leads can be connected in parallel to supply power, or the leads can be grouped to supply power according to groups; the drain electrodes of all the TFTs on the base layer are respectively connected with the corresponding pixel electrodes.
Referring to the example given in fig. 2, the gates of the TFTs in each row of erase units are connected to the same first conductive line, the sources of the TFTs in each column of erase units are connected to the same second conductive line, and the drains of the TFTs are connected to the corresponding pixel electrodes. The first conductive lines may be applied with the same or similar voltages, and the second conductive lines may be applied with the same or similar voltages.
Fig. 3 and 4 respectively show wiring diagrams of the TFTs, and referring to fig. 3, the first electrode plate represents a pixel electrode region on the base layer to which the TFTs are connected; the second plate represents a conductive layer; the drain electrode of the TFT can be also connected with a capacitor, the leading-out electrode wire of each capacitor is connected with the leading-out electrode wire of the conducting layer, and the TFT is switched on to charge the capacitor. In fig. 3, the storage capacitor C1 is used to prevent voltage abrupt change, but it is also possible to use the distributed capacitance formed between the conductive layer and the underlying layer to realize the storage capacitor C1, and in this case, the storage capacitor C1 may be omitted, as shown in fig. 4.
In this embodiment, the base layer is a TFT glass layer on which different circuit structures can be integrated by a semiconductor process.
In some embodiments, electrode lines are respectively led out from the base layer and the conductive layer; is used for connecting a voltage driving circuit which can provide required voltage. Of course, the voltage driving circuit may also be integrated on the substrate layer.
As an optional implementation mode, the conductive particles are added into the frame glue, and the electrodes of the whole conductive layer are connected to the substrate layer, so that the electrode extraction of the whole module is extracted from the substrate layer, and the method is simpler and more stable than the original method of respectively extracting the electrodes from the conductive layer and the substrate layer.
In this embodiment, the voltage applied to all or a set part of the TFTs in the threshold off state may be applied all the time or only when the partial erasing is required, so as to save power consumption.
As a specific embodiment, a function key may be provided on the liquid crystal writing device, by which whether or not a set voltage is applied to all or a set part of the TFTs so as to be in a critical off state can be selected.
As an alternative embodiment, a wireless signal receiving unit may be disposed on the liquid crystal writing device, and configured to receive a first wireless signal, so as to apply a set voltage to the conductive layer, and apply a set voltage to the set TFT, so that the TFT is in a critical cut-off state;
receiving a second wireless signal, and controlling the discharge between the basal layer and the conductive layer according to the received ambient light intensity and the luminous intensity which is sent by the optical erasing piece and is adaptively adjusted according to the ambient light intensity;
a third wireless signal is received to remove the voltage applied to the conductive layer and the base layer.
The wireless transmission signal may be provided by a dedicated optical wiping member.
In this embodiment, the optical erasing member further includes:
a power supply unit configured to supply power to the other units;
an ambient light detection unit configured to detect an intensity of ambient light;
and the trigger unit is configured to trigger the illumination unit to emit the light source with the set illumination intensity after receiving the set trigger signal.
In other embodiments, the optical erasing piece is provided with a wireless signal transmitting unit, and the wireless signal transmitting unit is started by pressing a key, or the wireless signal transmitting unit is started after the illumination unit on the optical erasing piece meets the triggering condition or is triggered and lightened.
The wireless signal transmitting unit transmits a wireless signal to the liquid crystal writing device; after receiving the first wireless signal, a wireless signal receiving unit on the liquid crystal writing device controls all or part of set TFTs to apply set voltage so as to enable the TFTs to be in a critical cut-off state;
after the wireless signal receiving unit on the liquid crystal writing device receives the second wireless signal, the wireless signal receiving unit controls the discharge between the basal layer and the conductive layer according to the received environment light intensity and the luminous intensity which is sent by the optical erasing piece and is adaptively adjusted according to the environment light intensity;
and after the erasing is finished, the wireless signal receiving unit on the liquid crystal writing device controls the applied voltage to cancel after receiving the third wireless signal.
Therefore, the liquid crystal writing device can be controlled to apply voltage only when the liquid crystal writing device needs to be erased, and energy consumption is saved.
Compared with the film material structure commonly used in the current market, the technical scheme for realizing the local erasing of the liquid crystal writing device has the advantages that the control process for realizing the local erasing is simpler and more accurate, the control circuit is simpler, the erasing effect is better, and the influence on other areas is avoided; the cost can be greatly saved, and the reliability of the product is ensured.
As shown in fig. 5, a preferred form of the optical erasing member includes: the device comprises a shell 1, wherein a power supply, a control unit, a first light-emitting source and an infrared detection unit 7 are arranged in the shell 1, and an ambient light detection element 11 is arranged on the shell; the power supply supplies power to the control unit, the first light-emitting source and the infrared detection unit 7, and the control unit is respectively communicated with the first light-emitting source, the ambient light detection element 11 and the infrared detection unit 7;
the infrared detection unit 7 comprises an infrared emitting piece and an infrared receiving piece which are oppositely arranged; the bottom of the shell 1 is provided with an opening for emitting and incidence of infrared signals. The infrared signal sent by the infrared transmitting piece is emitted through the emitting hole, reflected by the shielding object (the liquid crystal writing board body), returned through the incident hole and received by the infrared receiving piece.
In this embodiment, the embedding of environment light detecting element is in the outer wall of casing and with external environment intercommunication, it is specific, it has the recess to open on the outer wall of casing, the embedding of environment light detecting element is fixed in the recess, and the connecting wire passes the recess through the wire hole after and be connected with the control unit.
In other embodiments, it is understood that the outer wall of the housing is provided with a through groove for communicating the inside and the outside environment of the housing, and the environment light detection element is fixed in the through groove and directly connected with the control unit through a connecting wire.
Of course, the ambient light detection element is directly fixed on the outer side surface of the housing, and a person skilled in the art can select the ambient light detection element according to a specific working condition, which is not described herein again.
When the control unit detects that the infrared receiving piece receives the infrared signal, the first light-emitting light source is controlled to start emitting light.
In some embodiments, the optical erasing member is further provided with a capacitive touch detection device and an acceleration sensor; the capacitive touch detection device and the acceleration sensor respectively send detection signals to the control unit; the capacitive touch detection device is arranged on the periphery of the shell 1 and used for detecting that a user touches the optical erasing piece; the acceleration sensor is arranged on the main control panel and used for detecting the motion posture of the optical erasing piece.
When the fact that a user touches the optical erasing piece and the light emitting surface of the optical erasing piece is opposite to the liquid crystal writing device body is detected, the control unit controls the first light emitting source to be turned on to emit light.
Of course, the above-mentioned condition for controlling the first light-emitting source to start emitting light may be set according to actual needs, and may be set to be satisfied simultaneously, or may be set to be satisfied only partially; the embodiment can effectively avoid the false triggering of the optical erasing piece by controlling the starting condition of the first light-emitting source.
In other embodiments, a wireless signal transmitting unit is further arranged in the optical erasing piece, and the wireless signal transmitting unit is communicated with the control unit; the control unit can send a wireless signal to the liquid crystal writing device body through the wireless transmitting unit so that the liquid crystal writing device body is loaded with a set voltage and the condition of optical erasing is met.
In still other embodiments, the side surface of the optical erasing member is further provided with a second light-emitting source and a switch for controlling the second light-emitting source to be turned on and off; in this embodiment, the first light source may be configured to erase a writing trace in a large area, the second light source is configured to erase a writing trace in a small area, and both the first light source and the second light source can achieve light intensity adjustment under the control of the control unit.
A circuit board 4 is arranged in a shell 1 of the optical erasing piece, and a control unit, an acceleration sensor and a wireless transmitting unit are respectively arranged on the circuit board 4; the power supply is a battery and is arranged in the battery bin 2; the outer side of the shell 1 is provided with a circle of capacitive touch detection devices, and a circle of conductive rings 6 is arranged in the shell 1. At least one light-emitting lamp bead 3 is arranged in the shell 1 and is used as a first light-emitting source; the bottom of the shell 1 opposite to the light-emitting lamp bead 3 is a light source exit port, and a convex lens 8 is arranged between the light-emitting lamp bead 3 and the light source exit port. The lamp bead 3 is arranged at the focus position of the convex lens 8, and light emitted by the lamp bead 3 is changed into uniform parallel light through the convex lens 8 and is emitted from the light source exit port. Set up light screen 5 between luminous lamp pearl 3 and the convex lens 8, avoid the light source to emit from above the lamp pearl for the light that lamp pearl 3 sent all jets out from the exit port.
The infrared emitting part and the infrared receiving part are oppositely arranged at the positions, close to the light source exit port, of the two sides of the convex lens 8, the infrared signals emitted by the infrared emitting part are emitted out through the light source exit port, and can return from the light source exit port to be received by the infrared receiving part after being shielded by the liquid crystal writing device body within a set distance.
At this time, the light source outlet is used as both the outlet of the light source of the optical erasing piece and the opening for detecting the outgoing and incoming infrared signals.
The magnet group 10 is arranged at the bottom of the optical erasing piece shell 1 and can be adsorbed on the liquid crystal writing device body, so that the storage and the taking are convenient; in addition, a soft contact layer, such as felt 9, is arranged on the optical erasing part at the contact position with the liquid crystal writing device body, and is used for preventing the optical erasing part from scratching the liquid crystal writing panel.
Of course, it is understood that in some other embodiments, the specific optical erasing structure may be other structures, as long as the illuminance can be adaptively adjusted according to the intensity of the ambient light, and details are not described here.
Example 2:
on the basis of the adaptive ambient light liquid crystal writing device disclosed in embodiment 1, 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.
The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (10)
1. The utility model provides a device is write to liquid crystal of self-adaptation ambient light, includes that clipboard and light erase the piece, and the clipboard is including the conducting layer, bistable liquid crystal layer and the stratum basale that set gradually, and a plurality of units of erasing that the integration has main control unit and array form to arrange on the stratum basale are equipped with the pixel electrode in every unit of erasing and with the thin film field effect transistor TFT that the pixel electrode is connected, its characterized in that:
the liquid crystal writing device also comprises an ambient light detection element, and the ambient light detection element is in wireless or wired communication with the main control unit;
and controlling the discharge time interval between the substrate layer and the conductive layer according to the ambient light intensity and the illuminance of the optical erasing piece.
2. The ambient light adaptive liquid crystal writing apparatus of claim 1, wherein:
the ambient light detection element is located on the optical erasing member.
3. The ambient light adaptive liquid crystal writing apparatus of claim 1, wherein:
the optical erasing piece comprises a power supply unit, and the power supply unit is a battery, a wired charging power supply or a wireless charging power supply.
4. A partial erasing method using the liquid crystal writing apparatus of any one of claims 1 to 3, characterized in that:
the method comprises the following steps:
the difference between the time interval from power-up to the erase start voltage of the non-erase region caused by the ambient light and the time interval from power-up to discharge of the erase region is greater than a preset amount.
5. The partial erasing method of claim 4, wherein:
the preset quantity is determined according to the relationship between the TFT photocurrent and the illumination intensity.
6. The partial erasing method of claim 4, wherein:
and adjusting the illumination of the optical erasing piece according to the intensity of the ambient light so that the illumination of the optical erasing piece is greater than the intensity of the ambient light and is a preset multiple of the intensity of the ambient light.
7. The partial erasing method of claim 6, wherein:
the preset multiple is determined according to the relationship between the TFT photocurrent and the illumination, and is greater than or equal to 2.
8. A bistable liquid crystal writing board comprising the liquid crystal writing device of any one of claims 1-3; alternatively, the local erasing method of any one of claims 4 to 7 is used.
9. A bistable liquid crystal blackboard comprising a liquid crystal writing device according to any one of claims 1 to 3; alternatively, the local erasing method of any one of claims 4 to 7 is used.
10. A bistable liquid crystal drawing board comprising a liquid crystal writing instrument according to any of claims 1 to 3; alternatively, the local erasing method of any one of claims 4 to 7 is used.
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| CN113867024B (en) * | 2021-09-24 | 2023-12-08 | 京东方科技集团股份有限公司 | Liquid crystal handwriting board, handwriting system and control method of handwriting system |
| CN113848659B (en) * | 2021-09-26 | 2023-11-10 | 京东方科技集团股份有限公司 | Optical erasing assembly, writing system and control method thereof |
| WO2023097425A1 (en) * | 2021-11-30 | 2023-06-08 | 京东方科技集团股份有限公司 | Array substrate, handwriting tablet, eraser, handwriting tablet system and pattern erasing method |
| CN114647120B (en) * | 2022-03-14 | 2023-10-17 | 京东方科技集团股份有限公司 | Liquid crystal handwriting board and control method thereof |
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