阅读说明：本技术 一种基于tft的电磁定位方法及系统 (TFT-based electromagnetic positioning method and system ) 是由 李清波 杨猛训 于 2021-09-02 设计创作，主要内容包括：本发明公开了一种基于TFT的电磁定位方法及系统,包括TFT基板,所述TFT基板上包括多条行驱动线和多条列驱动线；控制相邻的两根行驱动线电连接,形成多个用于感应电磁信号的第一方向线圈；控制相邻的两根列驱动线电连接,形成多个用于感应电磁信号的第二方向线圈；通过检测各第一方向线圈和各第二方向线圈感应信号的强度及频率,确定电磁信号发射件的位置及电磁信号频率。本发明电磁定位方法及系统不改变现有的TFT基板结构,仅需要增加简单的信号处理电路结构,无需设置其他额外的定位辅助元件,结构简单、易于实现,成本低。(The invention discloses an electromagnetic positioning method and system based on a TFT (thin film transistor), which comprises a TFT substrate, wherein the TFT substrate comprises a plurality of row driving lines and a plurality of column driving lines; controlling two adjacent row driving wires to be electrically connected to form a plurality of first directional coils for inducing electromagnetic signals; controlling two adjacent column driving wires to be electrically connected to form a plurality of second direction coils for inducing electromagnetic signals; and determining the position of the electromagnetic signal emitting piece and the frequency of the electromagnetic signal by detecting the strength and the frequency of the induction signal of each first direction coil and each second direction coil. The electromagnetic positioning method and the system do not change the existing TFT substrate structure, only need to add a simple signal processing circuit structure, do not need to arrange other additional positioning auxiliary elements, and have simple structure, easy realization and low cost.)

1. The electromagnetic positioning method based on the TFT is characterized by comprising a TFT substrate, wherein the TFT substrate comprises a plurality of row driving lines and a plurality of column driving lines;

controlling two adjacent row driving wires to be electrically connected to form a plurality of first directional coils for inducing electromagnetic signals;

controlling two adjacent column driving wires to be electrically connected to form a plurality of second direction coils for inducing electromagnetic signals;

and determining the position of the electromagnetic signal emitting piece and the frequency of the electromagnetic signal by detecting the strength and the frequency of the induction signal of each first direction coil and each second direction coil.

2. The TFT-based electromagnetic positioning method of claim 1, wherein controlling two adjacent row driving lines to be electrically connected comprises:

every two adjacent row driving lines are used as one group, and the row driving lines are not shared among the groups; and controlling the two row driving lines in each group to be electrically connected at a first end and output electromagnetic induction signals at a second end.

3. The method of claim 1, wherein controlling two adjacent column driving lines to be electrically connected comprises:

every two adjacent row driving lines are used as one group, and the row driving lines are not shared among the groups; and controlling the two column driving lines in each group to be electrically connected at a first end and output electromagnetic induction signals at a second end.

4. The electromagnetic positioning method based on the TFT is characterized by comprising a TFT substrate, wherein the TFT substrate comprises a plurality of row driving lines and a plurality of column driving lines;

controlling the two line driving lines to be electrically connected according to a set rule to form a plurality of first directional coils for inducing electromagnetic signals;

controlling the two column driving wires to be electrically connected according to a set rule to form a plurality of second direction coils for inducing electromagnetic signals;

and determining the position of the electromagnetic signal emitting piece and the frequency of the electromagnetic signal by detecting the strength and the frequency of the induction signal of each first direction coil and each second direction coil.

5. The TFT-based electromagnetic positioning method of claim 4, wherein controlling the two row driving lines to be electrically connected according to a set rule comprises:

taking the row driving lines within the interval set distance as a group, and not sharing the row driving lines among the groups;

and controlling every two row driving wires in each group to be electrically connected at a first end according to a set rule, and outputting an electromagnetic induction signal at a second end.

6. The TFT-based electromagnetic positioning method of claim 4, wherein controlling the two column driving lines to be electrically connected according to a set rule comprises:

taking the row driving lines within the interval set distance as a group, and not sharing the row driving lines among the groups;

and controlling every two column driving wires in each group to be electrically connected at a first end according to a set rule, and outputting an electromagnetic induction signal at a second end.

7. The method according to claim 1 or 4, wherein the position of the electromagnetic signal emitter and the frequency of the electromagnetic signal are determined by detecting the strength and the frequency of the induction signal of each first direction coil and each second direction coil, and the method comprises:

performing spectrum analysis on the electromagnetic induction signal of each first directional coil to obtain the frequency and the intensity of the electromagnetic induction signal; taking the position of the first direction coil with the maximum electromagnetic induction signal intensity as a second direction coordinate of the electromagnetic signal transmitting piece;

performing spectrum analysis on the electromagnetic induction signal of each second direction coil to obtain the frequency and the intensity of the electromagnetic induction signal; taking the position of the second direction coil with the maximum electromagnetic induction signal intensity as a first direction coordinate of the electromagnetic signal transmitting piece;

and finally determining the position coordinates and the signal frequency of the electromagnetic signal emitting piece.

8. The TFT-based electromagnetic positioning method of claim 1 or 4, wherein the electromagnetic induction signal output by each first direction coil or second direction coil is firstly subjected to differential processing with a set electromagnetic induction reference signal, and then subjected to spectrum analysis to eliminate spatial signal interference.

9. The TFT-based electromagnetic positioning method of claim 1 or 4, wherein, when performing the next-time electromagnetic positioning detection, the detection is performed within a range of a peripheral setting area of the position of the electromagnetic signal emitting member detected at the previous time.

10. The TFT-based electromagnetic positioning device is characterized by comprising a TFT substrate, wherein the TFT substrate comprises a plurality of row driving lines and a plurality of column driving lines;

every two adjacent row driving lines are used as one group, and the row driving lines are not shared among the groups;

controlling two row driving wires in each group to be electrically connected at a first end, and respectively connecting a first analog switch and a second analog switch at a second end; the first analog switch outputs an electromagnetic induction signal, and the second analog switch is grounded; or the two row driving wires in each group are controlled to be electrically connected at the second end, one row driving wire is controlled to be grounded at the first end through the control unit, and the other row driving wire outputs an electromagnetic induction signal;

every two adjacent row driving lines are used as one group, and the row driving lines are not shared among the groups;

controlling two column driving wires in each group to be electrically connected at a first end, and respectively connecting a third analog switch and a fourth analog switch at a second end; the third analog switch outputs an electromagnetic induction signal, and the fourth analog switch is grounded; or the two column driving lines in each group are controlled to be electrically connected at the second end, one column driving line is controlled to be grounded at the first end through the control unit, and the other column driving line outputs an electromagnetic induction signal.

11. The TFT-based electromagnetic positioning device is characterized by comprising a TFT substrate, wherein the TFT substrate comprises a plurality of row driving lines and a plurality of column driving lines;

taking the row driving lines within the interval set distance as a group, and not sharing the row driving lines among the groups;

controlling every two line driving lines in each group to be electrically connected at a first end according to a set rule, and respectively connecting a first analog switch and a second analog switch at a second end; the first analog switch outputs an electromagnetic induction signal, and the second analog switch is grounded;

or, controlling every two row driving lines in each group to be electrically connected at the second end according to a set rule, controlling one row driving line to be grounded at the first end through a control unit, and outputting an electromagnetic induction signal by the other row driving line;

taking the row driving lines within the interval set distance as a group, and not sharing the row driving lines among the groups;

controlling every two column driving wires in each group to be electrically connected at a first end according to a set rule, and respectively connecting a third analog switch and a fourth analog switch at a second end; the third analog switch outputs an electromagnetic induction signal, and the fourth analog switch is grounded;

or, according to a set rule, every two column driving lines in each group are controlled to be electrically connected at the second end, one column driving line is controlled to be grounded at the first end through the control unit, and the other column driving line outputs an electromagnetic induction signal.

12. A TFT-based electromagnetic positioning apparatus as claimed in claim 10 or 11, wherein the output of the first analog switch is amplified and then connected to a controller, and the controller is configured to perform a spectrum analysis on the input electromagnetic induction signal to obtain the frequency and intensity of the signal;

and taking the position of the first direction coil with the maximum electromagnetic induction signal intensity as a second direction coordinate of the electromagnetic signal transmitting piece.

13. A TFT-based electromagnetic positioning apparatus as claimed in claim 10 or 11, wherein the output of the third analog switch is amplified and then connected to the controller, and the controller is configured to perform a spectrum analysis on the input electromagnetic induction signal to obtain the frequency and intensity of the signal;

and taking the position of the second direction coil with the maximum electromagnetic induction signal intensity as the first direction coordinate of the electromagnetic signal transmitting piece.

14. The TFT-based electromagnetic positioning apparatus according to claim 10 or 11, wherein an output of the first analog switch and an output of the set first-direction reference coil are respectively connected to two input terminals of a first operational amplifier, an output of the first operational amplifier is amplified and connected to a controller, and the controller is configured to perform a spectrum analysis on an input electromagnetic induction signal to obtain a frequency and an intensity of the signal.

15. The TFT-based electromagnetic positioning apparatus of claim 14, wherein the set first-direction reference coils are specifically:

dividing the TFT substrate into an upper part and a lower part, and selecting a first direction coil at the upper part as a first direction reference coil output by a first analog switch at the lower part; selecting a first direction coil at the lower part as a first direction reference coil output by the first analog switch at the upper part;

or, selecting a first direction coil which is separated from the current first analog switch output by a set distance as a first direction reference coil.

16. The TFT-based electromagnetic positioning apparatus according to claim 10 or 11, wherein an output of the third analog switch and an output of the set second direction reference coil are respectively connected to two input terminals of a second operational amplifier, an output of the second operational amplifier is amplified and then connected to a controller, and the controller is configured to perform a spectrum analysis on an input electromagnetic induction signal to obtain a frequency and an intensity of the signal.

17. The TFT-based electromagnetic positioning apparatus of claim 16, wherein the set second direction reference coils are specifically:

dividing the TFT substrate into a left part and a right part, and selecting a second direction coil at the left part as a second direction reference coil output by a third analog switch at the right part; selecting a second direction coil at the right part as a second direction reference coil output by a third analog switch at the left part;

or selecting a second direction coil which is separated from the current third analog switch output by a set distance as a second direction reference coil.

18. A liquid crystal writing apparatus, comprising: the conductive layer, the bistable liquid crystal layer and the substrate layer are arranged in sequence; the TFT-based electromagnetic positioning apparatus of any of claims 10 or 11 integrated on the substrate layer.

19. A liquid crystal writing apparatus as defined in claim 18, further comprising: an electromagnetic pen/eraser capable of emitting an electromagnetic signal; and determining the frequency of the electromagnetic signal emitted by the electromagnetic pen/erasing piece and the position of the electromagnetic signal acting on the liquid crystal writing device according to the frequency and the intensity of the detected electromagnetic induction signal.

20. An electronic paper, comprising: the conductive layer, the polar material layer and the substrate layer are arranged in sequence; the TFT-based electromagnetic positioning apparatus of any of claims 10 or 11 integrated on the substrate layer.

21. The electronic paper of claim 20, further comprising: an electromagnetic pen/eraser capable of emitting an electromagnetic signal; and determining the frequency of the electromagnetic signal emitted by the electromagnetic pen/erasing piece and the position acted on the liquid crystal writing device according to the frequency and the intensity of the detected electromagnetic induction signal.

Technical Field

The invention relates to the technical field of electromagnetic positioning, in particular to an electromagnetic positioning method and system based on a TFT (thin film transistor).

Background

Bistable liquid crystal writing/displaying devices (such as writing tablets or electronic papers) are currently on the market, which operate on the principle of writing and/or erasing by using the bistable character of the liquid crystal. For example, cholesteric liquid crystal is used as a writing board, the writing pressure track of a writing pen is recorded by changing the liquid crystal state at a pen point through the 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 pressure track on the liquid crystal writing board disappears to realize erasing.

The prior art discloses a TFT substrate-based liquid crystal writing/display device comprising: a conductive layer, a bistable liquid crystal layer/polar liquid crystal material layer, and a substrate layer sequentially disposed; the TFT substrate is integrated on the base layer, a plurality of pixel units are arranged on the TFT substrate in an array mode, and a pixel electrode and a thin film field effect transistor (TFT) connected with the pixel electrode are arranged in each pixel unit; the TFT corresponding to each row of pixel units is connected by at least one first wire (hereinafter referred to as a row driving wire or a Gate wire) and supplies control voltage; the TFT corresponding to each row of pixel units is connected by at least one second lead (hereinafter referred to as a row driving line or a source line) and supplies input voltage; the voltage supplied to each first conducting wire (row driving wire or Gate wire) and each second conducting wire (column driving wire or source wire) on the TFT substrate is controlled to achieve a set voltage difference between the set pixel unit and the conducting layer, so that local erasing or display of a set area is realized.

For the liquid crystal writing/displaying device with the above structure, the common positioning methods include: infrared positioning, optical or ultrasonic/distance sensor positioning, capacitive screen positioning, electromagnetic positioning, or the like.

When infrared positioning is utilized, one or more groups of infrared transmitting/receiving arrays are required to be added at the edge of the liquid crystal writing device; when the ultrasonic/distance sensor is used for positioning, at least two pairs of ultrasonic transceiving sensors are required to be added on the liquid crystal writing/displaying device; when the capacitive screen is used for positioning, the capacitive screen needs to be specially added. Therefore, the investment cost is increased, the volume and the thickness of the liquid crystal writing/displaying device are increased, and the experience satisfaction degree of a user on a product is influenced.

The prior art also discloses electromagnetic positioning methods based on the above liquid crystal writing/displaying devices, such as: the TFT substrate is combined with the electromagnetic positioning net, so that the TFT substrate is easily affected due to the unevenness of the electromagnetic positioning net, the display effect is further affected, and meanwhile, the input cost and the thickness of the liquid crystal writing/displaying device are increased; or, on the basis of the existing TFT substrate structure, a TFT and a corresponding induction coil for performing electromagnetic positioning are separately added, and this method needs to change the structure of the TFT substrate, which makes the implementation difficult.

Disclosure of Invention

Based on the above, the invention provides the electromagnetic positioning method and system based on the TFT, the structure of the original TFT substrate is not required to be changed, the thickness of the liquid crystal writing/displaying device is not increased, and the product cost is greatly reduced.

In order to achieve the above object, according to a first aspect of the present invention, there is provided a TFT-based electromagnetic positioning method, including a TFT substrate including a plurality of row driving lines and a plurality of column driving lines thereon;

controlling two adjacent row driving wires to be electrically connected to form a plurality of first directional coils for inducing electromagnetic signals;

controlling two adjacent column driving wires to be electrically connected to form a plurality of second direction coils for inducing electromagnetic signals;

and determining the position of the electromagnetic signal emitting piece and the frequency of the electromagnetic signal by detecting the strength and the frequency of the induction signal of each first direction coil and each second direction coil.

According to a second aspect of the present invention, there is provided a TFT-based electromagnetic positioning method, comprising a TFT substrate including a plurality of row drive lines and a plurality of column drive lines thereon;

controlling the two line driving lines to be electrically connected according to a set rule to form a plurality of first directional coils for inducing electromagnetic signals;

controlling the two column driving wires to be electrically connected according to a set rule to form a plurality of second direction coils for inducing electromagnetic signals;

and determining the position of the electromagnetic signal emitting piece and the frequency of the electromagnetic signal by detecting the strength and the frequency of the induction signal of each first direction coil and each second direction coil.

According to a third aspect of the present invention, there is provided a TFT-based electromagnetic positioning apparatus comprising a TFT substrate including a plurality of row drive lines and a plurality of column drive lines thereon;

every two adjacent row driving lines are used as one group, and the row driving lines are not shared among the groups; controlling two row driving wires in each group to be electrically connected at a first end, and respectively connecting a first analog switch and a second analog switch at a second end; the first analog switch outputs an electromagnetic induction signal, and the second analog switch is grounded;

every two adjacent row driving lines are used as one group, and the row driving lines are not shared among the groups; controlling two column driving wires in each group to be electrically connected at a first end, and respectively connecting a third analog switch and a fourth analog switch at a second end; the third analog switch outputs an electromagnetic induction signal, and the fourth analog switch is grounded.

According to a fourth aspect of the present invention, there is provided a TFT-based electromagnetic positioning apparatus comprising a TFT substrate including a plurality of row drive lines and a plurality of column drive lines thereon;

taking the row driving lines within the interval set distance as a group, and not sharing the row driving lines among the groups; controlling every two line driving lines in each group to be electrically connected at a first end according to a set rule, and respectively connecting a first analog switch and a second analog switch at a second end; the first analog switch outputs an electromagnetic induction signal, and the second analog switch is grounded;

taking the row driving lines within the interval set distance as a group, and not sharing the row driving lines among the groups; controlling every two column driving wires in each group to be electrically connected at a first end according to a set rule, and respectively connecting a third analog switch and a fourth analog switch at a second end; the third analog switch outputs an electromagnetic induction signal, and the fourth analog switch is grounded.

According to a fifth aspect of the present invention, there is provided a liquid crystal writing apparatus comprising: the conductive layer, the bistable liquid crystal layer and the substrate layer are arranged in sequence; the TFT-based electromagnetic positioning device is integrated on the substrate layer.

According to a sixth aspect of the present invention, there is provided electronic paper comprising: the conductive layer, the polar material layer and the substrate layer are arranged in sequence; the TFT-based electromagnetic positioning device is integrated on the substrate layer.

Compared with the prior art, the invention has the beneficial effects that:

(1) the electromagnetic positioning method and the system do not change the existing TFT substrate structure, only need to add a simple signal processing circuit structure, do not need to arrange other additional positioning auxiliary elements, and have simple structure, easy realization and low cost.

(2) The electromagnetic positioning system processes the electromagnetic induction output signal and the set reference output signal through the operational amplifier, can eliminate the interference of space signals, and improves the detection precision.

(3) After the electromagnetic induction signals output by the electromagnetic positioning system are subjected to frequency spectrum processing, the frequency and the intensity of the signals induced by each coil can be obtained; the position of the coil with the maximum signal intensity is selected as the position of the electromagnetic transmitting piece, the calculation process is simple, and the positioning is accurate; meanwhile, according to the detected signal frequency, the frequency emitted by the electromagnetic emitting piece can be determined, and further the action state of the electromagnetic emitting piece and the liquid crystal writing/displaying device can be determined.

Additional features and advantages 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 TFT-based electromagnetic positioning system according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of difference processing performed on the output of the first direction reference coil according to the embodiment of the present invention.

Detailed Description

It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the disclosure. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. 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.

Example one

According to the embodiment of the invention, the electromagnetic positioning method based on the TFT comprises a TFT substrate, wherein a plurality of pixel units are arranged on the TFT substrate in an array manner, and each pixel unit is internally provided with a pixel electrode and a thin film field effect transistor (TFT) connected with the pixel electrode;

the TFT corresponding to each row of pixel units is connected by at least one first wire (hereinafter referred to as a row driving wire or a Gate wire) and supplies control voltage;

the TFT corresponding to each row of pixel units is connected by at least one second lead (hereinafter referred to as a row driving line or a source line) and supplies input voltage;

controlling two adjacent row driving wires to be electrically connected to form a plurality of first directional coils for inducing electromagnetic signals; controlling two adjacent column driving wires to be electrically connected to form a plurality of second direction coils for inducing electromagnetic signals; and determining the position of the electromagnetic signal emitting piece and the frequency of the electromagnetic signal by detecting the strength and the frequency of the induction signal of each first direction coil and each second direction coil.

Specifically, every two adjacent row driving lines are taken as a group, and the row driving lines are not shared in each group, so that a plurality of first direction coils are formed; and controlling the two row driving lines in each group to be electrically connected at a first end and output electromagnetic induction signals at a second end. The electromagnetic induction signal of each first direction coil is subjected to Discrete Fourier Transform (DFT) to obtain the frequency and the intensity of the electromagnetic induction signal; and taking the position of the first direction coil with the maximum electromagnetic induction signal intensity as a second direction coordinate, namely a vertical coordinate, of the electromagnetic signal transmitting piece.

Every two adjacent row driving lines are used as a group, and the row driving lines are not shared in each group to form a plurality of second direction coils; and controlling the two column driving lines in each group to be electrically connected at a first end and output electromagnetic induction signals at a second end. The electromagnetic induction signal of each second direction coil is subjected to Discrete Fourier Transform (DFT) to obtain the frequency and the intensity of the electromagnetic induction signal; and taking the position of the second direction coil with the maximum electromagnetic induction signal intensity as the first direction coordinate, namely the abscissa, of the electromagnetic signal transmitting piece.

Finally, determining the position coordinate of the electromagnetic signal emitting piece according to the positioned first direction coordinate and the positioned second direction coordinate; while the frequency of the electromagnetic induction signal is determined.

It should be noted that the first end may refer to an end close to the driving chip, a switch may be added between every two adjacent row driving lines, and the driving chip controls the on/off of the switch, so as to electrically connect or disconnect the two row driving lines at the first end.

Of course, the first end may also refer to an end away from the driving chip, and at this time, the second end is electrically connected, and the driving chip can be directly utilized at the first end to realize grounding of one of the driving lines, and perform spectrum processing and detection on the sensing signal output by the other driving line.

It should be noted that the row driving lines or the column driving lines on the TFT substrate are connected only when positioning is performed, and the row driving lines or the column driving lines cannot be connected when display or erase control is performed; generally, the control time for performing display or erasing is shorter than the control time for performing positioning.

In some embodiments, the positioning can be performed in the gap of displaying or erasing when displaying or erasing; when writing, the positioning can be carried out all the time.

As an alternative embodiment, in order to increase the electromagnetic positioning speed, considering that the electromagnetic emitting member (electromagnetic pen or eraser) usually does not move in a large range, when performing electromagnetic positioning at the next moment, the detection is performed in a set area range around the position of the electromagnetic emitting member detected at the previous moment; if the electromagnetic emitting part can not be detected, the detection in the global range is carried out.

As an alternative implementation manner, in order to eliminate the interference of the spatial signal to the electromagnetic induction signal, the electromagnetic induction signal output by each first direction coil or second direction coil is first subjected to a difference processing with a set electromagnetic induction reference signal, and then subjected to a spectrum analysis, so that the spatial signal interference can be eliminated.

Example two

According to an embodiment of the invention, a TFT-based electromagnetic positioning method is disclosed, which includes a TFT substrate, and the structure of the TFT substrate is the same as that in the first embodiment, and is not described again.

Controlling the two line driving lines to be electrically connected according to a set rule to form a plurality of first directional coils for inducing electromagnetic signals; controlling the two column driving wires to be electrically connected according to a set rule to form a plurality of second direction coils for inducing electromagnetic signals; and determining the position of the electromagnetic signal emitting piece and the frequency of the electromagnetic signal by detecting the strength and the frequency of the induction signal of each first direction coil and each second direction coil.

Specifically, the row driving lines within a set distance are set as one group, and the row driving lines are not shared among the groups; and controlling every two row driving wires in each group to be electrically connected at a first end according to a set rule, and outputting an electromagnetic induction signal at a second end. Such as: every four row driving wires are used as a group, and in each group, a first wire and a third wire can be controlled to be electrically connected to form a first directional coil, and a second wire and a fourth wire are electrically connected to form a first directional coil; the electromagnetic induction signal of each first direction coil is subjected to Discrete Fourier Transform (DFT) to obtain the frequency and the intensity of the electromagnetic induction signal; taking the position of the first direction coil with the maximum electromagnetic induction signal intensity as a second direction coordinate of the electromagnetic signal transmitting piece;

taking the row driving lines within the interval set distance as a group, and not sharing the row driving lines among the groups; and controlling every two column driving wires in each group to be electrically connected at a first end according to a set rule, and outputting an electromagnetic induction signal at a second end. The electromagnetic induction signal of each second direction coil is subjected to Discrete Fourier Transform (DFT) to obtain the frequency and the intensity of the electromagnetic induction signal; taking the position of the second direction coil with the maximum electromagnetic induction signal intensity as a first direction coordinate of the electromagnetic signal transmitting piece;

finally, determining the position coordinate of the electromagnetic signal emitting piece according to the positioned first direction coordinate and the positioned second direction coordinate; while the frequency of the electromagnetic induction signal is determined.

It should be noted that the first end may refer to an end close to the driving chip, a switch may be added between every two adjacent row driving lines, and the driving chip controls the on/off of the switch, so as to electrically connect or disconnect the two row driving lines at the first end.

Of course, the first end may also refer to an end away from the driving chip, and at this time, the second end is electrically connected, and the driving chip can be directly utilized at the first end to realize grounding of one of the driving lines, and perform spectrum processing and detection on the sensing signal output by the other driving line.

It should be noted that the row driving lines or the column driving lines on the TFT substrate are connected only when positioning is performed, and the row driving lines or the column driving lines cannot be connected when display or erase control is performed; generally, the control time for performing display or erasing is shorter than the control time for performing positioning.

In some embodiments, the positioning can be performed in the gap of displaying or erasing when displaying or erasing; when writing, the positioning can be carried out all the time.

As an alternative embodiment, in order to increase the electromagnetic positioning speed, considering that the electromagnetic emitting member (electromagnetic pen or eraser) usually does not move in a large range, when performing electromagnetic positioning at the next moment, the detection is performed in a set area range around the position of the electromagnetic emitting member detected at the previous moment; if the electromagnetic emitting part can not be detected, the detection in the global range is carried out.

As an alternative implementation manner, in order to eliminate the interference of the spatial signal to the electromagnetic induction signal, the electromagnetic induction signal output by each first direction coil or second direction coil is first subjected to differential processing with a set electromagnetic induction reference signal, and then subjected to discrete fourier transform DFT, so that the spatial signal interference can be eliminated.

EXAMPLE III

According to an embodiment of the present invention, an embodiment of an electromagnetic positioning device based on a TFT is disclosed, which includes a TFT substrate, and the structure of the TFT substrate is the same as that in the first embodiment, and is not described again.

The TFT substrate comprises a plurality of row driving lines and a plurality of column driving lines;

referring to fig. 1, every two adjacent row driving lines are grouped, and the row driving lines are not shared between the groups; controlling two row driving wires in each group to be electrically connected at a first end, and respectively connecting a first analog switch and a second analog switch at a second end; the first analog switch outputs an electromagnetic induction signal, and the second analog switch is Grounded (GND); the two connected row driving lines form a first direction coil.

Every two adjacent row driving lines are used as one group, and the row driving lines are not shared among the groups; controlling two column driving wires in each group to be electrically connected at a first end, and respectively connecting a third analog switch and a fourth analog switch at a second end; the third analog switch outputs an electromagnetic induction signal, and the fourth analog switch is Grounded (GND); the two connected lines form a second direction coil.

It should be noted that, when the number of the pins of the single analog switch is not enough, the output may be implemented by cascading a plurality of analog switches.

By way of example, the first end refers to an end close to the driving chip, and the two row driving lines in each group can be controlled to be electrically connected at the first end through the original gate driving chip, and the two column driving lines in each group can be controlled to be electrically connected at the first end through the original source driving chip.

In this embodiment, the output of the first analog switch is amplified and then connected to the controller MCU, and the controller MCU is configured to perform frequency spectrum processing on the input electromagnetic induction signal to obtain the frequency and intensity of the signal; and taking the position of the first direction coil with the maximum electromagnetic induction signal intensity as a second direction coordinate of the electromagnetic signal transmitting piece.

The output of the third analog switch is amplified and then is accessed to a controller MCU, and the controller MCU is configured to perform frequency spectrum processing on the input electromagnetic induction signal to obtain the frequency and the intensity of the signal; and taking the position of the second direction coil with the maximum electromagnetic induction signal intensity as the first direction coordinate of the electromagnetic signal transmitting piece.

As an alternative implementation manner, in order to eliminate the interference of the spatial signal to the electromagnetic induction signal, referring to fig. 2, the output of the first analog switch and the output of the set first-direction reference coil are respectively connected to two input ends of a first operational amplifier, the output of the first operational amplifier is connected to a controller MCU after passing through the amplifier, and the controller MCU is configured to perform discrete fourier transform DFT on the input electromagnetic induction signal to obtain the frequency and the intensity of the signal.

Similarly, the output of the third analog switch and the output of the set second direction reference coil are respectively connected to two input ends of the second operational amplifier, the output of the second operational amplifier is connected to the controller MCU after passing through the amplifier, and the controller MCU is configured to perform Discrete Fourier Transform (DFT) on the input electromagnetic induction signal to obtain the frequency and the intensity of the signal.

In the embodiment, the set row driving line or the set column driving line can be selectively grounded through the analog switch; in the actual detection process, a first line driving line in one group is grounded, and a second line driving line is used as output to detect the electromagnetic induction signal; then, the first line driving line is used as output, the second line driving line is grounded, and the detection of the electromagnetic induction signal is carried out again; this can provide accuracy and precision of electromagnetic positioning.

In this embodiment, the first direction reference coil is determined in two ways:

the first method is as follows:

averagely dividing the TFT substrate into an upper part and a lower part, and selecting a first-direction coil from the upper half part as a first-direction reference coil output from the lower half part; and selecting a first direction coil at the lower half part as a first direction reference coil output by the upper half part. Of course, the device can be divided into two parts according to a set proportion.

The second method comprises the following steps:

and selecting a first direction coil which is spaced from the current output by a set distance as a first direction reference coil. It should be noted that the first direction reference coil should be selected to be far enough away from the current output.

Similarly, the second direction reference coil is determined in two ways:

the first method is as follows:

averagely dividing the TFT substrate into a left part and a right part, and selecting a second direction coil in the left half part as a second direction reference coil output in the right half part; and selecting one second direction coil as a second direction reference coil output by the left half part in the right half part. Of course, the device can be divided into two parts according to a set proportion.

The second method comprises the following steps:

and selecting a second direction coil which is separated from the current output by a set distance as a second direction reference coil.

It should be noted that the second direction reference coil should be selected to be far enough away from the current output.

The electromagnetic positioning system does not change the existing TFT substrate structure, only needs to add a simple signal processing circuit structure, does not need to arrange other additional positioning auxiliary elements, and has simple structure, easy realization and low cost.

Example four

According to an embodiment of the present invention, an embodiment of an electromagnetic positioning device based on a TFT is disclosed, which includes a TFT substrate, and the structure of the TFT substrate is the same as that in the first embodiment, and is not described again.

The TFT substrate comprises a plurality of row driving lines and a plurality of column driving lines;

taking the row driving lines within the interval set distance as a group, and not sharing the row driving lines among the groups; and controlling every two row driving lines in each group to be electrically connected at a first end according to a set rule, such as: every four row driving wires are used as a group, and in each group, a first wire and a third wire can be controlled to be electrically connected to form a first directional coil, and a second wire and a fourth wire are electrically connected to form a first directional coil; the second ends are respectively connected with a first analog switch and a second analog switch; the first analog switch outputs an electromagnetic induction signal, and the second analog switch is grounded;

taking the row driving lines within the interval set distance as a group, and not sharing the row driving lines among the groups; controlling every two column driving wires in each group to be electrically connected at a first end according to a set rule, and respectively connecting a third analog switch and a fourth analog switch at a second end; the third analog switch outputs electromagnetic induction signals, and the fourth analog switch is grounded.

The connection mode of the output ends of the first analog switch and the third analog switch is the same as that in the third embodiment, and the description is omitted.

EXAMPLE five

According to an embodiment of the present invention, there is disclosed an embodiment of a liquid crystal writing apparatus including: the conductive layer, the bistable liquid crystal layer and the substrate layer are arranged in sequence; the substrate layer is integrated with the electromagnetic positioning system described in the first embodiment.

As an alternative embodiment, the liquid crystal writing apparatus further comprises: an electromagnetic pen/eraser capable of emitting an electromagnetic signal; and determining the frequency of the electromagnetic signal emitted by the electromagnetic pen/erasing piece and the position acted on the liquid crystal writing device according to the frequency and the intensity of the detected electromagnetic induction signal.

Such as: when the electromagnetic pen is contacted with the writing panel, the frequency of the emitted electromagnetic signal is f1, and when the electromagnetic pen is lifted and is not contacted with the writing panel, the frequency of the emitted electromagnetic signal is f 2; when the electromagnetic pen stops working, no electromagnetic signal is sent out. The current working state of the electromagnetic pen can be judged according to the frequency of the detected induction signal; if the frequency of the detected electromagnetic induction signal is f1, the electromagnetic pen is in contact with the writing panel at the moment, and if the frequency of the detected electromagnetic induction signal is f2, the electromagnetic pen is lifted and is not in contact with the writing panel at the moment; if the electromagnetic induction signal is not detected, it indicates that the electromagnetic pen is not stopped or is far away from the writing panel.

Of course, as long as the frequency of the sensing signal is f1 or f2, the position of the electromagnetic pen is located. The same holds true for the electromagnetic eraser.

The handwriting can be displayed and stored or erased based on the electromagnetic positioning position.

The liquid crystal writing board of the embodiment can be a liquid crystal blackboard, a liquid crystal writing board, a liquid crystal drawing board or other products.

EXAMPLE six

According to an embodiment of the present invention, there is disclosed an embodiment of an electronic paper, including: the conductive layer, the polar material layer and the substrate layer are arranged in sequence; the substrate layer is integrated with the electromagnetic positioning system described in the first embodiment.

As an optional implementation, the electronic paper further includes: an electromagnetic pen/eraser capable of emitting an electromagnetic signal; and determining the frequency of the electromagnetic signal emitted by the electromagnetic pen/erasing piece and the position acted on the liquid crystal writing device according to the frequency and the intensity of the detected electromagnetic induction signal.

Such as: when the electromagnetic pen is contacted with the writing panel, the frequency of the emitted electromagnetic signal is f1, and when the electromagnetic pen is lifted and is not contacted with the writing panel, the frequency of the emitted electromagnetic signal is f 2; when the electromagnetic pen stops working, no electromagnetic signal is sent out. The current working state of the electromagnetic pen can be judged according to the frequency of the detected induction signal; if the frequency of the detected electromagnetic induction signal is f1, the electromagnetic pen is in contact with the writing panel at the moment, and if the frequency of the detected electromagnetic induction signal is f2, the electromagnetic pen is lifted and is not in contact with the writing panel at the moment; if the electromagnetic induction signal is not detected, it indicates that the electromagnetic pen is not stopped or is far away from the writing panel.

Of course, as long as the frequency of the sensing signal is f1 or f2, the position of the electromagnetic pen is located. The same holds true for the electromagnetic eraser.

The handwriting can be displayed and stored or erased based on the electromagnetic positioning position.

The electronic paper of the embodiment may include electronic paper related products such as an electronic paper reader or an electronic paper tablet computer.

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.