Electromagnetic position input device and input position detection method

Abstract

The present invention discloses an electromagnetic position input device and an input position detection method, the input position detection method comprising the steps of: detecting the direction of the induced current in the antenna coil, when the first antenna coil is detected, the direction of the induced current therein meets the determination condition, determining the input position of the input pen as the first input position, wherein the first input position is located at the position of the first antenna coil, etc. The present invention can determine the current actual input position of the input pen within the sensing range of which antenna coil by the direction of the induced current in the antenna coil, and can avoid or reduce the occurrence of the input point "rebound" phenomenon in the prior art. After avoiding the "rebound" phenomenon, there is no need to set a restriction structure to limit the user's operable range when producing electromagnetic position input device products, and the hardware resources of the electromagnetic position input device can be fully utilized. The present invention is widely used in the field of electromagnetic position input technology.

Description

Technical Field

[0001] The present invention relates to the technical field of electromagnetic position input, and in particular to an electromagnetic position input device and an input position detection method. Background Art

[0002] The electromagnetic position input device is also called an electromagnetic input board, a digital board, etc., and its main part is an input panel. The input panel includes a plurality of antenna coils arranged along a vertical plane and a horizontal plane. When an input pen that generates a magnetic field by itself or generates a magnetic field under the excitation of an antenna coil is used to write on the input panel, the antenna coil senses the magnetic field generated by the input pen. In the prior art, the relative position of the input pen and the input panel can be determined by processing the measured values ​​such as the magnetic field strength or magnetic field energy sensed by the antenna coil through an algorithm in a processor, and the input position of the input pen on the input panel can be further determined, and then the pen strokes, handwriting or operation effects can be displayed at the input position or other corresponding positions.

[0003] Figure 1 is a schematic diagram of one of the above-mentioned prior arts, Figure 1 Each of the small figures in the figure represents a different position of the input pen on the input panel. The image below each small figure represents the magnetic field strength or magnetic field energy size sensed by the antenna coils of each part of the input panel near the input pen. The intersection in each small figure represents the input position of the input pen recognized by the input panel. The dotted arrow in each small figure represents the movement trajectory of the input pen. When the actual input position of the input pen is inside the input panel, the position of the maximum magnetic field strength sensed by each antenna coil of the input panel is the same as the actual input position. At this time, the technical means of detecting the input position by the maximum magnetic field strength in the prior art has a higher accuracy. However, when the actual input position of the input pen is outside the input panel, the input panel should not recognize the input position of the input pen. However, the magnetic field generated by the input pen will still be sensed by the antenna coils of the input panel. There may even be a situation where the magnetic field strength inside the input panel is greater than that at the edge of the input panel. At this time, it will appear Figure 1 The last two small figures in the figure show that although the input pen has been moved outside the input panel, the input panel recognizes that the input position of the input pen is inside the input panel. Therefore, when the input pen is continuously moved from the inside to the outside of the input panel, the input point will "bounce back", causing inconvenience or misoperation. The existing method to deal with this phenomenon is to set a restriction structure on the input panel, such as using a baffle to cover the edge of the input panel, so that the user can only input at the inner part of the input panel, which is equivalent to not allowing the edge of the input panel to be used, resulting in a waste of resources. Summary of the invention

[0004] In view of at least one of the above technical problems, an object of the present invention is to provide an electromagnetic position input device and an input position detection method.

[0005] In one aspect, an embodiment of the present invention includes an input position detection method for an electromagnetic position input device, wherein the electromagnetic position input device includes a plurality of antenna coils, wherein the antenna coils are used to detect a magnetic field generated by an input pen, and the input position detection method includes:

[0006] Detecting the direction of the induced current in part or all of the antenna coil; the induced current is the current generated by the magnetic field generated by the input pen cutting the antenna coil;

[0007] When the first antenna coil is detected, the direction of the induced current in the first antenna coil satisfies a determination condition, and the input position of the input pen is determined to be a first input position, and the first input position is located at the position of the first antenna coil.

[0008] Furthermore, the input position detection method further includes:

[0009] When it is not detected that the direction of the induced current in any of the antenna coils satisfies the determination condition, the input position of the input pen is detected again.

[0010] Further, the detecting the direction of the induced current in part or all of the antenna coils includes:

[0011] detecting the intensity of the induced current in all the antenna coils;

[0012] For one or more antenna coils having the largest induced current intensity, the direction of the induced current is detected.

[0013] Furthermore, the determination condition includes: at the same time, the direction of the induced current in the antenna coil is the same as the direction of the excitation current; and the excitation current is the current input to the antenna coil to excite the input pen.

[0014] Further, determining the input position of the input pen as the first input position includes:

[0015] Obtaining a coordinate range corresponding to the first antenna coil;

[0016] The first input position is determined within a coordinate range of the first antenna coil.

[0017] Further, determining the first input position within the coordinate range of the first antenna coil includes:

[0018] detecting the intensity of the induced current in the first antenna coil;

[0019] The specific coordinates of the input position of the input pen are determined according to the intensity of the induced current in the first antenna coil and the coordinate range corresponding to the first antenna coil.

[0020] On the other hand, an embodiment of the present invention further includes an electromagnetic position input device, including:

[0021] multiple antenna coils;

[0022] Synchronous signal detector; the synchronous signal detector is used to detect the direction of the induced current in part or all of the antenna coil; the induced current is the current generated by the magnetic field generated by the input pen cutting the antenna coil;

[0023] Processor; the processor is used to determine that the input position of the input pen is the first input position when the first antenna coil is detected and the direction of the induced current in the first antenna coil meets the judgment condition, and the first input position is located at the position where the first antenna coil is located.

[0024] Furthermore, the processor is also used to re-detect the input position of the input pen when it is not detected that the direction of the induced current in any of the antenna coils meets the determination condition.

[0025] Furthermore, the electromagnetic position input device further comprises:

[0026] A synchronization signal controller; the synchronization signal controller is used to drive the antenna coil to stimulate the input pen.

[0027] Furthermore, the synchronization signal detector is used to output a signal higher than a reference potential or lower than a reference potential when it is detected that the direction of the induced current in one of the antenna coils is the same as the direction of the excitation current at the same moment, and to output a signal lower than a reference potential or higher than a reference potential when it is detected that the direction of the induced current in one of the antenna coils is opposite to the direction of the excitation current at the same moment.

[0028] The beneficial effect of the present invention is that the electromagnetic position input device in the embodiment can determine which antenna coil's inductive range the current actual input position of the input pen is within by the direction of the induced current in the antenna coil, thereby avoiding or reducing the occurrence of the input point "rebound" phenomenon in the prior art. After avoiding the "rebound" phenomenon, when producing electromagnetic position input device products, there is no need to set a restriction structure to limit the user's operable range, and the hardware resources of the electromagnetic position input device can be fully utilized. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1It is a working principle diagram of an electromagnetic position input device in the prior art;

[0030] Figure 2 and Figure 3 A schematic diagram of the relationship between the relative positions of the input pen and the antenna coil and the direction of the induced current in the embodiment;

[0031] Figure 4 A schematic diagram of the structure of an antenna coil installed in the electromagnetic position input device in the embodiment;

[0032] Figure 5 2 is a circuit diagram of the electromagnetic position input device in the embodiment. DETAILED DESCRIPTION

[0033] In this embodiment, considering the working principle of the electromagnetic position input device and the input pen, refer to Figure 2 and Figure 3 , which illustrates the positional relationship between the winding iron core on the input pen used to generate a magnetic field and the antenna coil on the input panel, as well as the direction of the magnetic field generated by the winding iron core and the direction of the induced current formed by the antenna coil being cut by the magnetic lines of force generated by the winding iron core. Figure 2 In the example, the winding core on the input pen is outside an antenna coil. When the magnetic field generated by the winding core cuts Figure 2 When the antenna coil is in the center, the direction of the induced current generated in the antenna coil is counterclockwise. Figure 3 In the example, the winding core on the input pen is inside an antenna coil. When the magnetic field generated by the winding core cuts Figure 3 When the antenna coil in the input pen is in the input position, the direction of the induced current generated in the antenna coil is clockwise. In fact, since the antenna coil with the largest winding core is excited to generate a magnetic field, according to the law of electromagnetic induction, when the actual input position of the input pen is outside the inductive range of a certain antenna coil, the magnetic field generated by the input pen cuts the direction of the induced current generated by the antenna coil, which is opposite to the direction of the excitation current in the antenna coil; when the actual input position of the input pen is within the inductive range of a certain antenna coil, the magnetic field generated by the input pen cuts the direction of the induced current generated by the antenna coil, which is the same as the direction of the excitation current in the antenna coil.

[0034] exist Figure 2 and Figure 3 Based on the analysis Figure 4 Multiple antenna coils are shown. Figure 4 The multiple antenna coils shown are antenna coil structures widely used in current electromagnetic position input devices. The multiple antenna coils are evenly arranged at a certain interval, and there is a certain overlap range between two adjacent antenna coils. Figure 4In the figure, the actual input position of the input pen, that is, the winding core of the input pen is within the sensing range of the antenna coils numbered 1, 2, 3, and 4, but outside the sensing range of the antenna coils numbered 5 and 6. Figure 4 The direction of the excitation current in each antenna coil is clockwise. Figure 4 The direction of the arrows shown in the antenna coils is the direction of the induced current in the antenna coil determined according to the law of electromagnetic induction, wherein the directions of the induced currents of the antenna coils numbered 1, 2, 3, and 4 are all clockwise, and the directions of the induced currents of the antenna coils numbered 5 and 6 are all counterclockwise, that is, the directions of the induced currents of the antenna coils numbered 1, 2, 3, and 4 are the same as the directions of the excitation currents, and the directions of the induced currents of the antenna coils numbered 5 and 6 are opposite to the directions of the excitation currents.

[0035] Based on the above principles, the design Figure 5 The electromagnetic position input device shown mainly includes a processor, a synchronization signal controller, a synchronization signal detector and multiple antenna coils, and also includes a signal transmission buffer, a transmit and receive switching switch, a data multiplexer, a signal amplifier, a bandpass filter, a low-pass filter, an S / H sample and hold and an A / D converter, etc.

[0036] Figure 5 The basic principle of the circuit shown is: the processor controls the synchronous signal controller to output an excitation current to the antenna coil. The antenna coil can generate a magnetic field to excite the input pen under the drive of the excitation current, and the input pen is excited to obtain energy to generate the magnetic field. Devices such as the signal transmission buffer, the transceiver switching switch, and the data multiplexer respectively play the role of buffering delay of the drive signal, connecting and disconnecting, and selecting the antenna coil. After the magnetic field generated by the input pen is sensed by the antenna coil, the induced voltage or current signal is detected by the synchronous signal detector after being preprocessed by the signal amplifier and the bandpass filter in turn. In this embodiment, the synchronous signal detector is used to detect the direction of the voltage or current signal induced by the antenna coil. In this embodiment, the synchronous signal detector and the synchronous signal controller are linked to determine the direction of the voltage or current signal induced by the antenna coil. Specifically, if the direction of the voltage or current signal induced by the input pen coil is the same as the direction of the excitation current in the antenna coil, then the direction of the voltage or current signal induced by the antenna coil is determined to be positive; if the direction of the voltage or current signal induced by the input pen coil is opposite to the direction of the excitation current in the antenna coil, then the direction of the voltage or current signal induced by the antenna coil is determined to be reverse.

[0037] Specifically, the synchronization signal detector is set to: when the direction of the induced current in an antenna coil is detected to be in the same direction, a signal higher than the reference potential or lower than the reference potential is output; when the direction of the induced current in an antenna coil is detected to be in the opposite direction, a signal lower than the reference potential or higher than the reference potential is output. The reference potential can be half of the working voltage of the synchronization signal detector. The signal output by the synchronization signal detector is converted into a digital signal after being processed by the S / H sampling and holding device and the A / D converter, for example, 0 indicates that the synchronization signal detector outputs a signal higher than the reference potential or lower than the reference potential, and 1 indicates that the synchronization signal detector outputs a signal lower than the reference potential or higher than the reference potential, so as to trigger the processor to execute the corresponding steps.

[0038] In this embodiment, the processor also communicates with the transceiver switching switch and the data multiplexer, and determines which antenna coil the signal output by the synchronization signal detector representing the direction of the induced current in the antenna coil corresponds to through the working status of the transceiver switching switch and the data multiplexer.

[0039] In this embodiment, Figure 5 The electromagnetic position input device shown can execute the input position detection method in this embodiment. The input position detection method includes the following steps:

[0040] S1. Detect the intensity of the induced current in part or all of the antenna coil;

[0041] S2. When the first antenna coil is detected, the direction of the induced current in the first antenna coil satisfies the determination condition, and the input position of the input pen is determined to be the first input position, wherein the first input position is located at the position of the first antenna coil;

[0042] S3. When it is not detected that the direction of the induced current in any antenna coil satisfies the determination condition, the input position of the input pen is detected again.

[0043] In step S1, the processor may use a scanning method to detect the direction of the induced current in multiple antenna coils simultaneously or in sequence within a short period of time, and determine whether there is an antenna coil whose direction of the induced current meets the determination condition. When executing step S1, all antenna coils may be scanned, or part of the antenna coils may be scanned to improve the execution efficiency. If part of the antenna coils are scanned, the intensity of the induced current in all antenna coils may be detected first, and then one or more antenna coils with the largest induced current intensity may be determined, and the direction of the induced current may be detected for these antenna coils. Since the one or more antenna coils with the largest induced current intensity are generally the antenna coils closest to the input pen, and are more likely to be located at or near the actual input position of the input pen, one or more antenna coils to be scanned are first selected by the intensity of the induced current in the antenna coils, and then the direction of the induced current is detected for the selected one or more antenna coils, which can reduce the number of antenna coils to be scanned and detected with a considerable detection accuracy, thereby improving the execution efficiency.

[0044] In step S2, if an antenna coil is detected in which the direction of the induced current satisfies the determination condition, then this antenna coil is the first antenna coil in this embodiment. The direction of the induced current satisfies the determination condition, which means that at the same time, the direction of the induced current in the antenna coil is the same as the direction of the excitation current, that is, the direction of the induced current is positive.

[0045] Therefore, step S2 may specifically be: if the direction of the induced current in an antenna coil is detected to be positive, then the antenna coil is determined as the first antenna coil, and then the coordinate range on the input panel corresponding to the position of the first antenna coil is determined by querying the device parameters, and the first input position is determined within this coordinate range.

[0046] In this embodiment, by executing steps S1-S2, the direction of the induced current in the antenna coil can be used to determine which antenna coil's inductive range the current actual input position of the input pen is within, thereby avoiding the misjudgment caused by the input position being detected simply by the magnetic field strength or magnetic field energy generated by the input pen in the prior art, when the actual input position of the input pen moves outside the input panel but still generates a magnetic field effect on the antenna coil, thereby avoiding or reducing the occurrence of the input point "rebound" phenomenon in the prior art. After avoiding the "rebound" phenomenon, there is no need to set a restriction structure to limit the user's operable range when producing electromagnetic position input device products, and the hardware resources of the electromagnetic position input device can be fully utilized.

[0047] In step S3, if the processor cannot detect the first antenna coil in this embodiment, that is, cannot detect that the direction of the induced current in any antenna coil is positive, then the corresponding situation is that the input pen has moved out of the sensing range of all antenna coils in the input panel, or the user has not used the input pen for input at all. At this time, the processor will re-detect the input position of the input pen to avoid the "rebound" phenomenon. Before the processor detects the first antenna coil or other antenna coils with positive induced current other than the first antenna coil again, the input position of the input pen is maintained at the position detected when step S2 was last executed to improve execution efficiency.

[0048] In this embodiment, the electromagnetic position input device may further perform the following steps based on the execution of steps S1-S2 or S1-S3:

[0049] S4. Detecting the intensity of the induced current in the first antenna coil;

[0050] S5. Determine the specific coordinates of the input position of the input pen according to the intensity of the induced current in the first antenna coil and the coordinate range corresponding to the first antenna coil.

[0051] After executing steps S1-S2 or S1-S3, it can be determined that the actual input position of the input pen is within the coordinate range corresponding to the first antenna coil. At this time, the existing or newly developed means of calculating the input position coordinates according to the intensity of the induced current in the antenna coil can be applied to calculate the specific coordinates of the input position of the input pen, thereby determining the precise position of the input position of the input pen. Since steps S1-S2 or S1-S3 have been executed before executing steps S4-S5, the occurrence of the "rebound" phenomenon can be avoided, and since the range of the input position of the input pen has been confirmed by executing steps S1-S2 or S1-S3, the speed of executing steps S4-S5 is faster than the prior art of calculating the input position coordinates according to the intensity of the induced current in the antenna coil.

[0052] A computer program for executing the data processing method in this embodiment can be written and written into a computer device or a storage medium. When the computer program is read out and executed, the input position detection method in this embodiment is executed.

[0053] It should be noted that, unless otherwise specified, when a feature is referred to as "fixed" or "connected" to another feature, it may be directly fixed or connected to another feature, or it may be indirectly fixed or connected to another feature. In addition, the descriptions of up, down, left, right, etc. used in this disclosure are only relative to the relative positional relationship of the components of the present disclosure in the accompanying drawings. The singular forms of "a", "said" and "the" used in this disclosure are also intended to include the plural forms, unless the context clearly indicates other meanings. In addition, unless otherwise defined, all technical and scientific terms used in this embodiment have the same meaning as those generally understood by technicians in this technical field. The terms used in the specification of this embodiment are only for describing specific embodiments, not for limiting the present invention. The term "and / or" used in this embodiment includes any combination of one or more related listed items.

[0054] It should be understood that, although the term first, second, third etc. may be adopted to describe various elements in the present disclosure, these elements should not be limited to these terms. These terms are only used to distinguish the same type of elements from each other. For example, without departing from the scope of the present disclosure, the first element may also be referred to as the second element, and similarly, the second element may also be referred to as the first element. The use of any and all examples or exemplary language ("for example", "such as" etc.) provided by the present embodiment is only intended to better illustrate embodiments of the present invention, and unless otherwise required, the scope of the present invention will not be limited.

[0055] It should be appreciated that embodiments of the present invention may be implemented or enforced by computer hardware, a combination of hardware and software, or by computer instructions stored in a non-transitory computer-readable memory. The method may be implemented in a computer program using standard programming techniques - including a non-transitory computer-readable storage medium configured with a computer program, wherein the storage medium so configured causes the computer to operate in a specific and predefined manner - according to the methods and drawings described in the specific embodiments. Each program may be implemented in a high-level procedural or object-oriented programming language to communicate with a computer system. However, if desired, the program may be implemented in an assembly or machine language. In any case, the language may be a compiled or interpreted language. In addition, the program may be run on a programmed ASIC for this purpose.

[0056] In addition, the operations of the process described in this embodiment may be performed in any suitable order, unless otherwise indicated in this embodiment or otherwise clearly contradicted by the context. The process described in this embodiment (or variations and / or combinations thereof) may be performed under the control of one or more computer systems configured with executable instructions, and may be implemented as a code (e.g., executable instructions, one or more computer programs, or one or more applications) executed jointly on one or more processors, by hardware or a combination thereof. The computer program includes a plurality of instructions that may be executed by one or more processors.

[0057] Further, the method can be implemented in any type of computing platform that is operably connected to a suitable computer, including but not limited to a personal computer, a minicomputer, a mainframe, a workstation, a network or distributed computing environment, a separate or integrated computer platform, or in communication with a charged particle tool or other imaging device, etc. Various aspects of the present invention can be implemented in machine-readable code stored on a non-transitory storage medium or device, whether removable or integrated into a computing platform, such as a hard disk, an optical read and / or write storage medium, a RAM, a ROM, etc., so that it can be read by a programmable computer, and when the storage medium or device is read by the computer, it can be used to configure and operate the computer to perform the process described herein. In addition, the machine-readable code, or a portion thereof, can be transmitted via a wired or wireless network. When such media includes instructions or programs that implement the steps described above in conjunction with a microprocessor or other data processor, the invention described in this embodiment includes these and other different types of non-transitory computer-readable storage media. When programmed according to the methods and techniques of the present invention, the present invention also includes the computer itself.

[0058] The computer program can be applied to input data to perform the functions described in the present embodiment, thereby converting the input data to generate output data stored in a non-volatile memory. The output information can also be applied to one or more output devices such as a display. In a preferred embodiment of the present invention, the converted data represents a physical and tangible object, including a specific visual depiction of the physical and tangible object produced on the display.

[0059] The above is only a preferred embodiment of the present invention. The present invention is not limited to the above implementation. As long as the technical effect of the present invention is achieved by the same means, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the scope of protection of the present invention. Within the scope of protection of the present invention, its technical scheme and / or implementation method may have various modifications and changes.

Claims

1. An input position detection method for an electromagnetic position input device, wherein the electromagnetic position input device comprises a plurality of antenna coils, wherein the antenna coils are used to detect the magnetic field generated by an input pen, wherein: The input position detection method comprises: Detecting the direction of the induced current in part or all of the antenna coil; the induced current is the current generated by the magnetic field generated by the input pen cutting the antenna coil; When the first antenna coil is detected, the direction of the induced current in the first antenna coil satisfies the judgment condition, and the input position of the input pen is determined to be the first input position, and the first input position is located at the position of the first antenna coil; the judgment condition includes: at the same time, the direction of the induced current in the antenna coil is the same as the direction of the excitation current; the excitation current is the current input to the antenna coil to excite the input pen.

2. The input position detection method according to claim 1, characterized in that: The input position detection method further includes: When it is not detected that the direction of the induced current in any of the antenna coils satisfies the determination condition, the input position of the input pen is detected again.

3. The input position detection method according to claim 1 or 2, characterized in that: The detecting the direction of the induced current in part or all of the antenna coils comprises: detecting the intensity of the induced current in all the antenna coils; For one or more antenna coils having the largest induced current intensity, the direction of the induced current is detected.

4. The input position detection method according to claim 1 or 2, characterized in that: The step of determining the input position of the input pen as the first input position includes: Obtaining a coordinate range corresponding to the first antenna coil; The first input position is determined within a coordinate range of the first antenna coil.

5. The input position detection method according to claim 4, characterized in that: The determining the first input position within the coordinate range of the first antenna coil includes: detecting the intensity of the induced current in the first antenna coil; The specific coordinates of the input position of the input pen are determined according to the intensity of the induced current in the first antenna coil and the coordinate range corresponding to the first antenna coil.

6. An electromagnetic position input device, characterized in that: include: multiple antenna coils; Synchronous signal detector; The synchronous signal detector is used to detect the direction of the induced current in part or all of the antenna coil; The induced current is the current generated by the magnetic field generated by the input pen cutting the antenna coil; processor; The processor is used for, when the first antenna coil is detected and the direction of the induced current in the first antenna coil satisfies a determination condition, determining that the input position of the input pen is a first input position, and the first input position is located at the position where the first antenna coil is located; The determination condition includes: at the same time, the direction of the induced current in the antenna coil is the same as the direction of the excitation current; The excitation current is a current input to the antenna coil to excite the input pen.

7. The electromagnetic position input device according to claim 6, characterized in that: The processor is further configured to re-detect the input position of the input pen when it is not detected that the direction of the induced current in any of the antenna coils satisfies the determination condition.

8. The electromagnetic position input device according to claim 6 or 7, characterized in that: The electromagnetic position input device also includes: A synchronization signal controller; the synchronization signal controller is used to drive the antenna coil to stimulate the input pen.

9. The electromagnetic position input device according to claim 6 or 7, characterized in that: The synchronous signal detector is used to output a signal higher than the reference potential or lower than the reference potential when it is detected that the direction of the induced current in one of the antenna coils is the same as the direction of the excitation current at the same moment, and to output a signal lower than the reference potential or higher than the reference potential when it is detected that the direction of the induced current in one of the antenna coils is opposite to the direction of the excitation current at the same moment.

Images