Position detection device and position detection method

Abstract

The present invention provides a position detection device and method that appropriately prevent erroneous detection of touch input during pen input. The electronic device includes: a communication unit that receives acceleration information detected by a stylus having a built-in acceleration sensor; and a controller that detects a pen position indicating the position of the stylus within a touch surface and a touch position indicating the position of a finger within the touch surface, and outputs the detected pen position and touch position. The controller is configured to control the output of the touch position based on the acceleration information received by the communication unit (step S50).

Description

Technical Field

[0001] The present invention relates to a position detection device and a position detection method. Background Art

[0002] Position detection devices are known that support both input using fingers or palms (hereinafter referred to as "touch input") and input using a stylus (hereinafter referred to as "pen input"). In such position detection devices, touch input may be detected even though the user did not intend it, as a result of a part of the hand, such as a finger or palm, touching the touch surface while pen input is being performed. Therefore, to prevent such unintended touch input detection (hereinafter referred to as "false detection"), some position detection devices disable touch input when pen input is being detected, or ignore the area where touch input is being detected if the area is larger than a specified value (to prevent false palm touches).

[0003] Furthermore, styluses with built-in acceleration sensors and posture sensors are known. Patent Document 1 discloses an example of such a stylus. In the technology described in Patent Document 1, the detection results of the acceleration sensor and posture sensor are used to determine whether the stylus is in use and to determine the dominant hand of the user using the stylus.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2011-232806 Summary of the Invention

[0007] Problems to be solved by the invention

[0008] However, currently, it is difficult to sufficiently eliminate false detection in each of the above-mentioned processes for preventing false detection of touch input.

[0009] Therefore, one object of the present invention is to provide a position detection device and a program that can appropriately prevent erroneous detection of touch input using a part of the hand such as a finger or a palm during input using a stylus pen.

[0010] Means for solving problems

[0011] The position detection device of the present invention comprises: a communication unit, which receives acceleration information detected by an acceleration sensor from a stylus having a built-in acceleration sensor; and a controller, which detects a first position indicating the position of the stylus within a touch surface and a second position indicating the position of a finger within the touch surface, outputs the detected first position and second position, and controls the output of the second position based on the acceleration information received by the communication unit.

[0012] The program of the present invention is used to enable a computer having a communication unit that receives acceleration information detected by a stylus with a built-in acceleration sensor to perform the following steps: detecting a first position representing the position of the stylus within a touch surface and a second position representing the position of a finger within the touch surface, and outputting the detected first position and second position; and controlling the output of the second position based on the acceleration information received by the communication unit.

[0013] Effects of the Invention

[0014] According to the present invention, it is possible to preferably prevent erroneous detection of touch input during pen input. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 1 is a diagram showing the internal structure of the electronic device 10 according to the embodiment of the present invention.

[0016] Figure 2 It shows Figure 1 The internal structure of the stylus pen S is shown in FIG.

[0017] Figure 3 It shows Figure 1 The internal structure of the sensor 12 and the sensor controller 14 is shown.

[0018] Figure 4 It is shown by Figure 1 FIG. 1 is a process flow chart of a position detection process executed by the microprocessor 15 .

[0019] Figure 5 It is shown by Figure 1 FIG. 1 is a processing flowchart showing details of the pen position detection processing executed by the sensor controller 14 .

[0020] Figure 6 It is shown in Figure 5 1 is a flowchart showing details of the global scan performed in step S11.

[0021] Figure 7(a) is a diagram showing an example of the receiving strength of the pen signal received by the sensor controller at each ring coil LC in the global scan of the background technology (when the distance between the stylus pen S and the touch surface is relatively short), (b) is a diagram showing an example of the receiving strength of the pen signal received by the sensor controller at each ring coil LC in the global scan of the background technology (when the distance between the stylus pen S and the touch surface is relatively long), and (c) is a diagram showing an example of the receiving strength of the pen signal received by the sensor controller at each ring coil LC in the global scan of the background technology (when the distance between the stylus pen S and the touch surface is relatively long). Figure 6 FIG. 1 is a diagram showing an example of the reception intensity of the pen signal received by the sensor controller 14 at each loop coil LC during a global scan (when the distance between the stylus pen S and the touch surface is relatively long).

[0022] Figure 8 It is shown in Figure 5 FIG. 1 is a flowchart showing details of the partial scan performed in step S12.

[0023] Figure 9 It is shown in Figure 4 FIG. 5 is a processing flowchart showing details of the touch position detection flag determination processing executed in step S7.

[0024] Figure 10 is shown until Figure 9 FIG. 1 is a diagram showing an example of a case where the value of the touch position detection flag is indeterminate in the process up to step S49 shown. DETAILED DESCRIPTION

[0025] Below, with reference to the attached Figure 1 The embodiments of the present invention will be described in detail.

[0026] Figure 1 This figure shows the internal structure of an electronic device 10 according to an embodiment of the present invention. Electronic device 10 is typically a tablet terminal (computer) with a display, and is configured to function as a position detection device that detects the position of a stylus S (illustrated) and a user's finger F within a touch surface that also serves as the display surface of the display. However, electronic device 10 may also be configured using a digitizer without a display.

[0027] like Figure 1 As shown, electronic device 10 includes sensors 11 and 12, sensor controllers 13 and 14, a microprocessor 15, a machine learning unit 16, a host processor 17, and a communication unit 18. Sensor controllers 13 and 14, microprocessor 15, and machine learning unit 16 constitute a controller of the position detection device.

[0028] The sensor 11 is a capacitive touch sensor composed of multiple electrodes arranged on a touch surface. The sensor controller 13 is an integrated circuit that detects the position of a finger F on the touch surface by detecting changes in the capacitance generated between the electrodes that make up the sensor 11. The position of the finger F detected in this manner is hereinafter referred to as the "touch position." The sensor controller 13 is configured to sequentially write coordinate data representing the detected touch positions to the memory of the microprocessor 15.

[0029] The sensor 12 is an electromagnetic induction (EMR) touch sensor, which is composed of a plurality of loop coils arranged in the touch surface. The specific structure of the sensor 12 will be described later. Figure 3 The sensor controller 14 is an integrated circuit that generates a magnetic field by passing a current signal through the loop coils that make up the sensor 11. These loop coils receive reflected signals from the stylus S that enter the magnetic field, thereby detecting the position of the stylus S within the touch surface. Hereinafter, the signal received from the stylus S via the sensor 12 is referred to as the "pen signal," and the position of the stylus S within the touch surface is referred to as the "pen position."

[0030] The sensor controller 14 also has a function of receiving data sent by the stylus pen S by demodulating the pen signal sent by the stylus pen S. Hereinafter, the data received from the stylus pen S via the sensor 12 is referred to as "pen data." The pen data includes a pen pressure value indicating the pressure applied to the tip of the stylus pen S and an operation switch SW (see below) provided on the side or end of the stylus pen S. Figure 2 The sensor controller 14 is configured to write the coordinate data indicating the detected pen position and the received pen data to the memory of the microprocessor 15 in sequence.

[0031] The microprocessor 15 is a processor with built-in memory. The microprocessor 15 is configured to control the sensor controllers 13 and 14 by reading and executing programs stored in the memory. It also processes various data input from the sensor controllers 13 and 14 and outputs the results to the host processor 17. The processing performed by the microprocessor 15 includes processing to appropriately prevent erroneous detection of touch input during pen input. Details will be described later.

[0032] The machine learning unit 16 is a processor with built-in memory. The machine learning unit 16 is configured to read and execute programs stored in the memory, thereby functioning as a neural network performing supervised learning. Based on various information input from the microprocessor 15, the machine learning unit 16 outputs restriction information indicating whether to restrict the output of touch positions. As will be described in detail later, the microprocessor 15 is configured to suspend the output of touch positions if the restriction information output from the machine learning unit 16 indicates that the output of touch positions should be restricted.

[0033] The host processor 17 is the central processing unit of the electronic device 10. It is configured to control various components of the electronic device 10 and execute various applications, including the drawing application, by reading and executing programs stored in the electronic device's storage device. The drawing application performs processing such as generating stroke data based on positions and information supplied by the microprocessor 15, storing the data as digital ink in the storage device, and rendering the digital ink for display on the display.

[0034] The communication unit 18 is a functional unit for wireless communication based on a short-range wireless communication standard such as BLE (Bluetooth (registered trademark) Low Energy). In this embodiment, the communication unit 18 is responsible for communicating with the communication unit 20 of the stylus pen S (see the following description). Figure 2 The communication unit 18 is configured to output data received through communication with the stylus pen S to the microprocessor 15.

[0035] Figure 2 It shows Figure 1 , the stylus pen S is shown in FIG. As shown in FIG. , the stylus pen S includes a coil L, a variable capacitance capacitor VC, a fixed capacitance capacitor C, an operation switch SW, a communication unit 20 , an acceleration sensor 21 , and a battery 22 .

[0036] The coil L, the variable capacitance capacitor VC, and the fixed capacitance capacitor C are connected in parallel to form an LC resonance circuit. Furthermore, the operation switch SW is connected in series to the fixed capacitance capacitor C.

[0037] The variable-capacitance capacitor VC is a capacitor whose capacitance varies depending on the aforementioned pen pressure. The operating switch SW is located on the side or end of the stylus pen S and can be turned on and off by the user. The fixed-capacitance capacitor C is disconnected from the circuit when the operating switch SW is off and integrated into the circuit when the operating switch SW is on.

[0038] The accelerometer 21 is a three-axis inertial sensor capable of detecting the inertial motion of the stylus S in three dimensions. It should be noted that the accelerometer 21 can also be a one-axis or two-axis inertial sensor, but a three-axis inertial sensor can detect the tilt of the stylus S. Therefore, a three-axis inertial sensor is more suitable from the perspective of more appropriate output results from the machine learning unit 16.

[0039] The communication unit 20 is based on Figure 1 The communication unit 20 is a wireless communication functional unit having the same specifications as the communication unit 18 shown in FIG. The communication unit 20 is configured to be able to communicate with the communication unit 18. Through this communication, the communication unit 20 transmits data indicating the detection results of the acceleration sensor 21 (hereinafter referred to as "acceleration information") to the communication unit 18. The battery 22 serves to supply power to the acceleration sensor 21 and the communication unit 20.

[0040] Figure 3 It shows Figure 1 The internal structure of the sensor 12 and the sensor controller 14 is shown in FIG. As shown in the figure, the sensor 12 has a structure in which a plurality of loop coils LC are arranged in a rectangular plane area. One end of each loop coil LC is grounded, and the other end is connected to the sensor controller 14. Figure 3 In the figure, as an example of a plurality of loop coils LC, 24 X-side loop coils X1 to X2 extending in the y direction are shown. 24 and 18 Y-side loop coils Y1 to Y2 extending in the x-direction orthogonal to the y-direction. 18 . Below, the 32 ring coils X1~X 24 、Y1~Y 18 The description will be continued based on this premise, but the number of loop coils LC to be provided in the sensor 12 is not limited to this.

[0041] like Figure 3 As shown, the sensor controller 14 includes a selection circuit 30, a plurality of receivers 31, a control unit 37, an oscillator 38, and a current driver 39. Each receiver 31 includes an amplifier 32, a high-speed analog-to-digital converter (ADC) circuit 33, and a discrete Fourier transform (DFT) circuit 34.

[0042] The selection circuit 30 is connected to the other end of each ring coil LC, the input end of each receiving unit 31 and the output end of the current driver 39, and plays the role of selecting one or more ring coils LC and connecting them to the input end of each receiving unit 31 or the output end of the current driver 39 according to the control of the control unit 37.

[0043] Amplifier 32 is a circuit that amplifies the voltage signal supplied from selection circuit 30 and outputs it to high-speed ADC circuit 33. High-speed ADC circuit 33 generates a digital signal by sampling the voltage signal output from amplifier 32. DFT circuit 34 converts the digital signal generated by high-speed ADC circuit 33 from the time domain to the frequency domain to generate a digital signal for each frequency, and outputs it to control unit 37.

[0044] The control unit 37 is a processor with a built-in memory. The control unit 37 is configured to control the selection circuit 30 and acquire the above-mentioned pen position and pen data based on the output signals of each receiving unit 31 by reading and executing a program stored in the memory.

[0045] The oscillator 38 is a circuit that generates an AC signal of a predetermined frequency. The current driver 39 converts the AC signal output from the oscillator 38 into a current signal and supplies the current signal to the selection circuit 30 .

[0046] The acquisition of the pen position and pen data by the control unit 37 will be briefly described. First, the control unit 37 controls the selection circuit 30 so as to select one or more loop coils LC and connect them to the output terminal of the current driver 39. This causes a current signal to flow through the selected loop coil LC, generating the above-mentioned magnetic field. It should be noted that the loop coils X1 to X2 can also be connected to the loop coils X1 to X3. 24 、Y1~Y 18 A loop coil dedicated to generating a magnetic field is independently arranged along the outer circumference of the sensor 12 , and only this dedicated loop coil is selected in the above-mentioned stage.

[0047] If the stylus pen S enters the generated magnetic field, the coil L of the stylus pen S (see Figure 2 ) generates an induced voltage, accumulating charge in the variable capacitance capacitor VC and the fixed capacitance capacitor C (when the operating switch SW is turned on). After a predetermined time has passed since one or more toroidal coils LC were connected to the output end of the current driver 39, the control unit 37 controls the selection circuit 30 to select one or more toroidal coils LC and connect them to the input ends of different receiving units 31. The generation of the magnetic field from the toroidal coil LC is then terminated, and a pen signal is transmitted from the coil L of the stylus S. The frequency of the pen signal thus transmitted is equal to the resonant frequency of the aforementioned LC resonant circuit. The resonant frequency of the LC resonant circuit changes depending on the capacitance of the variable capacitance capacitor VC and the presence or absence of the connection of the fixed capacitance capacitor C, so the frequency of the pen signal reflects the aforementioned pen pressure value and switch information.

[0048] The control unit 37 obtains the pen signal reception strength at each loop coil LC based on the digital signals supplied from each receiving unit 31 and derives the pen position based on the obtained results. Furthermore, the control unit 37 obtains the pen signal frequency based on the digital signals supplied from each receiving unit 31 and thereby obtains the pen data (pen pressure value and switch information) transmitted by the stylus S. The control unit 37 outputs the thus obtained pen position and pen data to the microprocessor 15 each time the pen position and pen data are obtained.

[0049] Next, refer to the processing flow Figure 1 The position detection processing performed by the microprocessor 15 of this embodiment will be described in more detail. The following description details the processing performed by the microprocessor 15 to appropriately prevent erroneous detection of touch input during pen input. Furthermore, the pen position detection processing performed by the sensor controller 14 will also be described in detail.

[0050] Figure 4 : is a processing flow chart showing the position detection processing performed by the microprocessor 15. As shown in the figure, if the microprocessor 15 is powered on, it first initializes the pen detection flag and the touch position detection flag, which are variables (step S1). Specifically, the pen detection flag is set to "N (negative)", and the touch position detection flag is set to "implementable". It should be noted that the touch position detection flag is equivalent to the above-mentioned restriction information. Afterwards, the microprocessor 15 obtains the pen position, distance information and pen data written to the memory by the sensor controller 14 in step S29 or step S38 described later (step S2). It should be noted that the distance information is information indicating the distance between the stylus S and the touch surface.

[0051] Figure 5 It is shown that in order to generate Figure 4 The flowchart shows details of the pen position detection process performed by the control unit 37 of the sensor controller 14 based on the pen position, distance information, and pen data acquired in step S2. As shown in the flowchart, upon starting the pen position detection process, the control unit 37 first checks the pen detection flag (step S10). If the flag is "N," a global scan is started (step S11); if the flag is "Y (yes)," a local scan is started (step S12).

[0052] Figure 6 It is shown in Figure 5 Detailed processing flow chart of the global scan performed in step S11. When starting the global scan, the control unit 37 first selects a plurality of discretely arranged loop coils LC from among the plurality of loop coils LC constituting the sensor 12 (step S21). Figure 6 In this case, eight X-side loop coils X2, X5, X8, and X9 are selected from the loop coil X2 at intervals of two. 11 、X14 、X 17 、X 20 、X 23 And select 6 Y-side loop coils Y2, Y5, Y8, Y2 and Y3 from the loop coil Y2 in the manner of every 2 loop coils. 11 、Y 14 、Y 17 , that is, an example in which a total of 14 loop coils LC are selected. In this case, at least 14 receiving units 31 are provided in the sensor controller 13. The following description will be continued based on this example.

[0053] Next, the control unit 37 controls the selection circuit 30 so that the output terminal of the current driver 39 is commonly connected to the selected 14 loop coils LC (step S22). This causes a current signal to flow through the selected 14 loop coils LC, generating a magnetic field on the touch surface.

[0054] After a predetermined time has passed since step S22 was executed, control unit 37 controls selection circuit 30 so that the input end of receiver 31 is connected to each of the 14 selected loop coils LC (step S23). At this time, a different receiver 31 is connected to each loop coil LC. This allows control unit 37 to receive pen signals received by each loop coil LC in parallel.

[0055] Next, the control unit 37 accumulates the reception strength of the pen signal at each receiving unit 31 within a predetermined time (step S24). As described above, the control unit 37 receives the pen signal received by each loop coil LC in parallel, so it is possible to continue the accumulation while the pen signal is being transmitted. Therefore, it is possible to accumulate the reception strength of the pen signal for a longer period of time than when the pen signal received by each loop coil LC is received by time division. Figure 7 The effects obtained thereby will be described in more detail.

[0056] Figure 7 (a) and Figure 7 (b) are diagrams showing examples of the reception intensity of the pen signal received by the sensor controller at each loop coil LC in the global scan of the background art. Figure 7 (c) is shown in Figure 6 FIG is a diagram showing an example of the reception intensity of the pen signal received by the sensor controller 13 at each loop coil LC in the global scan shown. Figure 7 (a) shows the case where the distance information is relatively short. Figure 7 (b) and Figure 7 (c) shows the case where the distance information is relatively long. Figure 7 (b) and Figure 7 (c) shows a case where the distance information has the same value.

[0057] Figure 7 (a) and Figure 7 The sensor controller of (b) has only one receiving unit 31, and is configured to receive the pen signals received by each loop coil LC by time division. Figure 7 As shown in (a), if the distance information is relatively short, even with this time-division reception, sufficient reception strength can be achieved at each loop coil LC close to the stylus S. Therefore, the sensor controller can detect the stylus S. Specifically, if the distance information is within approximately 3 cm (for a stylus with an integrated circuit, power supply to the integrated circuit is required, so the distance is within 1.1 cm), the sensor controller can detect the stylus S.

[0058] However, if Figure 7 As shown in (b), if the distance information is relatively long, even with the short reception time limited by time-division reception, sufficient reception intensity cannot be achieved at each loop coil LC close to the stylus S. As a result, the sensor controller cannot detect the stylus S. Specifically, if the distance information exceeds 3 cm (or 1.1 cm), the sensor controller cannot detect the stylus S.

[0059] In order to pass the following Figure 9 In order to appropriately prevent erroneous detection of touch input during pen input by performing the processing shown, the sensor controller 13 needs to be able to detect the stylus S that is about 5 cm away from the touch surface. Figure 7 In the example shown in (c), the distance information is Figure 7 Although the values ​​are the same as those in the example shown in (b), sensor controller 14 is able to obtain sufficient reception strength at each loop coil LC close to stylus S. This is because providing a receiver 31 for each loop coil LC enables parallel reception of pen signals, resulting in a longer accumulation time of reception strength at each loop coil LC than in the background art. Thus, according to this embodiment, control unit 37 can detect stylus S at a greater distance than in the background art.

[0060] In addition, in the global scan of this embodiment, not all the loop coils LC are used, but only the multiple loop coils LC discretely arranged among the multiple loop coils LC (specifically, the eight X-side loop coils X2, X5, X8, X9, X10, X11, X12, X13, X14, X15, X16, X17, X18, X19, X20, X21, X30, X31, X40, X51, X60, X70, X80, X90, X19, X10, X11, X21, X31, X40, X51, X60, X70, X80, X80, X90, X19, X10, X21, X31, X40, X51, X60, X8 ... 11 、X 14 、X 17 、X 20 、X 23 and six Y-side loop coils Y2, Y5, Y8, and Y9 selected from the loop coil Y2 at intervals of two. 11 、Y14 、Y 17 This totals 14 loop coils LC) to receive pen signals. Even so, the stylus S can be detected on the entire touch surface. On the other hand, this can reduce the number of receiving units 31, reducing the number of components and manufacturing costs of the electronic device 10. It should be noted that in this embodiment, "every three" is used, but as long as the stylus S can be detected on the entire touch surface, it can also be set to "every one" or "every three". In addition, the spacing between the loop coils LC used for receiving pen signals does not need to be fixed.

[0061] return Figure 6 After completing step S24, the control unit 37 determines whether the stylus S is detected based on the finally obtained reception strength of each receiving unit 31 (steps S25 and S26). Specifically, the stylus S is determined to be detected if there is at least one receiving unit 31 with a reception strength greater than a predetermined value.

[0062] The control unit 37 that determines in steps S25 and S26 that the stylus pen S is not detected ends the global scan. On the other hand, the control unit 37 that determines in steps S25 and S26 that the stylus pen S is detected sets the pen detection flag to "Y" (step S27), and derives the pen position and distance information based on the receiving intensity of each receiving unit 31 (step S28). It should be noted that, regarding the distance information, a function or table that establishes a correspondence between the receiving intensity and the distance information is prepared in advance, and it can be derived by performing an operation based on the function or by referring to the table. Finally, the control unit 37 writes the derived pen position and distance information to the memory of the microprocessor 15 (step S29), and ends the global scan. Figure 5 As shown, the control unit 37 , having completed the global scan, returns to step S10 to continue the process.

[0063] Figure 8 It is shown in Figure 5 The following is a flowchart showing details of the partial scan performed in step S12. After starting the partial scan, the control unit 37 first controls the selection circuit 30 to select one or more transmission loop coils LC and connect the output of the current driver 39 to the selected transmission loop coils LC (step S30). It should be noted that the selected transmission loop coils LC can be predetermined or determined based on the latest pen position.

[0064] Next, the control unit 37 selects a predetermined number of loop coils LC based on the most recent pen position (step S31). After a predetermined time has passed since step S30 was executed, the selection circuit 30 is controlled so that the input end of the receiving unit 31 is connected to each of the selected loop coils LC (step S32). It should be noted that in step S31, the control unit 37 preferably selects a predetermined number of loop coils (e.g., three each) on the X and Y sides, starting with the loop coil closest to the most recent pen position. Furthermore, in step S32, it is preferred that different receiving units 31 be connected to each of the loop coils LC.

[0065] Next, the control unit 37 accumulates the reception strength of the pen signal at each receiving unit 31 within a predetermined time (step S33). Figure 6 Similarly to step S24 of the prior art, the accumulation time can be ensured to be longer than that of the prior art. Therefore, the control unit 37 can detect the stylus pen S at a farther position than that of the prior art, similarly to the case of the global scan.

[0066] Next, the control unit 37 determines whether the pen signal is successfully received in step S33 (step S34). In this determination, if the reception strength obtained in step S33 is above a predetermined threshold value, it is determined that the pen signal is successfully received. If it is determined in step S34 that the pen signal is not successfully received, the pen detection flag is set to "N" (step S39) and the local scan is terminated. In this case, if the pen signal is successfully received from the control unit 37, the pen signal is detected. Figure 5 As understood, a global scan is performed in the next and subsequent pen detection processes.

[0067] On the other hand, the control unit 37 that determines that the reception is successful in step S34 derives the pen position and distance information based on the reception strength of each receiving unit 31 (step S35). In addition, the control unit 37 obtains the frequency of the received pen signal (step S36), and obtains the pen data (pen pressure value and switch information) sent by the pen based on the obtained frequency (step S7). Thereafter, the control unit 37 writes the derived pen position and distance information and the obtained pen data to the memory of the microprocessor 15 (step S38), and ends the local scan. Figure 5 As shown, the control unit 37 , having completed the partial scan, returns to step S10 to continue the process.

[0068] return Figure 4 The microprocessor 15, having acquired the pen position, distance information, and pen data in step S2, outputs the acquired pen position and pen data to the host processor 17 and appends the acquired distance information to the time-series data of distance information stored in the memory (step S3). Furthermore, the microprocessor 15 temporarily stores the pen pressure value included in the acquired pen data in the memory (step S4).

[0069] Next, the microprocessor 15 obtains the touch position written to the memory by the sensor controller 13 (step S5), adds the obtained touch position to the time series data of the touch position stored in the memory (step S6), and then executes a touch position detection flag determination process (step S7).

[0070] Figure 9 It is shown in Figure 4 The processing flow chart of the details of the touch position detection flag determination processing executed in step S7 is shown in the figure. As shown in the figure, the microprocessor 15 first passes Figure 1 The microprocessor 15 performs near-field wireless communication with the stylus S using the communication unit 18 shown, thereby acquiring the aforementioned acceleration information from the stylus S (step S40). The acquired acceleration information is then appended to the time-series data of acceleration information stored in the memory (step S41). It should be noted that if the microprocessor 15 fails to receive the acceleration information in step S40, it appends a non-receipt message indicating that the information was not received to the time-series data.

[0071] Next, the microprocessor 15 determines whether the state in which the acceleration information cannot be received in step S40 has continued for more than a specified time by referring to the time series data of the acceleration information generated in step S41 (step S42). As a result, if it is determined that it has continued, the microprocessor 15 sets the touch position detection flag to "implementable" (step S43), and ends the touch position detection flag determination process. The state in which the acceleration information cannot be received has continued for more than a specified time, which means that the stylus S is not near the electronic device 10. As will be described in detail later, in this case, the output restriction of the touch position is lifted, and the touch position is output from the microprocessor 15 to the host processor 17. Therefore, touch input can be performed.

[0072] After determining in step S42 that the state has not continued, the microprocessor 15 then refers again to the time series data of the acceleration information generated in step S41 to determine whether the unchanged acceleration information received in step S40 has continued for a predetermined time or longer (step S44). If it is determined to have continued, the microprocessor 15 sets the touch position detection flag to "enable" (step S45), completing the touch position detection flag determination process. The state of unchanged acceleration information continuing for a predetermined time or longer means that the stylus S is in a state such as being placed on a table. As will be described in detail later, in this case as well, the output restriction on the touch position is lifted, enabling touch input.

[0073] If the microprocessor 15 determines in step S44 that the process is not continuing, it then determines the value of the pen detection flag (step S46). If the result is "N," meaning that the stylus S was not detected during the pen position detection process, the microprocessor 15 determines the value of the touch position detection flag based on the acceleration information received in step S40 (step S47). In a typical example, if the acceleration information indicates that the stylus S is moving in a predetermined direction (a direction determined by its orientation relative to the touch surface, for example, downward if the electronic device 10 is set with the touch surface facing upward), the microprocessor 15 sets the touch position detection flag to "not applicable." This is based on the assumption that if the stylus S is moving toward the touch surface, there is a high probability that pen input will begin soon. As will be described in detail later, in this case, the output of the touch position is restricted, and the touch position is not output from the microprocessor 15 to the host processor 17. Therefore, the user cannot perform touch input.

[0074] The microprocessor 15 which determines that the pen detection flag is "Y" in step S46 then determines whether Figure 4 The microprocessor 15 checks whether the pen pressure value temporarily stored in step S4 is greater than 0 (step S48). If the pen pressure value is greater than 0, the microprocessor 15 sets the touch position detection flag to "not implementable" (step S49). This is based on the fact that a pen pressure value greater than 0 indicates that the tip of the stylus pen S is in contact with the touch surface, indicating that pen input is currently being performed. As will be described in detail later, in this case, the output of the touch position is also restricted, preventing the user from performing touch input.

[0075] The microprocessor 15 that determines that the writing pressure value is 0 in step S48 then calculates the value of the writing pressure value based on the acceleration information received in step S40. Figure 4 The time series data of the distance information generated in step S3, Figure 4 The touch position detection flag value is determined based on the time series data of the touch position generated in step S8 (described later) (step S50), and the touch position detection flag determination process is terminated. The determination of step S50 is specifically performed using Figure 1 This is performed by the machine learning unit 16 shown in FIG. This point will be described in detail below.

[0076] The machine learning unit 16 is configured to take the combination of the time series data of the acceleration information, the distance information and the time series data of the touch position as input and output a touch position detection flag. In addition, the combination of the time series data of the acceleration information, the distance information and the time series data of the touch position and the touch position detection flag corresponding to the combination have been previously used as training data for the machine learning unit 16 to learn. It should be noted that the learning can be performed in the manufacturing stage of the electronic device 10, or can be performed by the user of the electronic device 10 himself, or can be performed by both. By configuring the machine learning unit 16 as described above, if the microprocessor 15 takes the acceleration information received in step S40, Figure 4 The time series data of the distance information generated in step S3, Figure 4 The time series data of the touch position generated in step S8 is input to the machine learning unit 16, and the value of the touch position detection flag ("implementable" or "inimplementable") is output from the machine learning unit 16. The microprocessor 15 determines the value of the touch position detection flag according to the output touch position detection flag value.

[0077] The process of step S50 is provided because there may be a case where the value of the touch position detection flag is indeterminate in the process up to step S49 . Figure 10 is a diagram showing an example of such a situation. In this example, the user is holding the stylus S with the thumb, middle finger, index finger, and ring finger of the right hand while performing touch input with the thumb and middle finger of the right hand. In this case, the distance between the stylus S and the electronic device 10 is close, so the communication unit 18 can receive acceleration information. In addition, the stylus S is detected in the pen position detection process. In addition, since the stylus S is held by a person's hand, the received acceleration information changes. Moreover, since the tip of the stylus S floats, the obtained pen pressure value becomes 0. Therefore, in the processing up to step S49, the value of the touch position detection flag is uncertain, and the processing of step S50 is executed.

[0078] In such Figure 10 In the case shown, it is difficult to determine whether the user will perform pen input next. By using the machine learning unit 16, it is possible to detect the user's subtle movements when performing pen input or not, and set the touch position detection flag to "not performable" or "performable", thereby appropriately preventing false detection of touch input during pen input.

[0079] return Figure 4After completing the touch position detection flag determination process in step S5, the microprocessor 15 determines the value of the touch position detection flag (step S8). If the value is "not feasible," the process returns to step S2. On the other hand, if the value is "feasible," the touch position obtained in step S5 is output to the host processor 17 (step S9), and the process returns to step S2.

[0080] As described above, according to the electronic device 10 of this embodiment, since the microprocessor 15 controls the output of the touch position based on the acceleration information, the time series data of the distance information, and the time series data of the touch position, it is possible to appropriately prevent the false detection of touch input during pen input compared to the background technology that only sets the touch input to be off when the stylus S is being detected and ignores the processing of the area when the area of ​​the area where the finger F is being detected is larger than a specified value.

[0081] Furthermore, according to the electronic device 10 of this embodiment, since multiple receiving units 31 are provided within the sensor controller 14 to receive pen signals from each loop coil LC in parallel, it is possible to detect a stylus S located at a distant location, compared to the conventional art in which pen signals from each loop coil LC are received by time division. Consequently, false detection of touch input during pen input can be further effectively prevented. However, as described above, false detection of touch input during pen input can be effectively prevented by controlling the output of the touch position based on acceleration information obtained by the acceleration sensor 21 of the stylus S, and parallel reception of pen signals from each loop coil LC is not essential.

[0082] While preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments at all, and the present invention can of course be implemented in various forms without departing from the spirit and scope of the present invention.

[0083] For example, in the above embodiment, the microprocessor 15 determines the value of the touch position detection flag (i.e., controls the output of the touch position) based on three types of data: acceleration information, time-series data of distance information, and time-series data of touch position. However, even if the value of the touch position detection flag is determined based on only one or two types of data, a certain degree of effect can be achieved. In this case, the input to the machine learning unit 16 also becomes only one or two types of data. Furthermore, the time-series data of acceleration information can be used instead of the instantaneous value of acceleration information, the instantaneous value of distance information can be used instead of the time-series data of distance information, and the instantaneous value of touch position can be used instead of the time-series data of touch position.

[0084] Furthermore, in the above embodiment, when the touch position detection flag is "not executable," the output of the touch position is limited by not outputting the touch position from the microprocessor 15 to the host processor 17. However, the touch position detection process itself performed by the sensor controller 13 may be stopped. Alternatively, the driver software of the host processor 17 may function as part of the controller of the position detection device, and the output of the touch position may be limited by stopping the supply of the touch position information from the driver software to the application.

[0085] Furthermore, in the above embodiment, an example of using an electromagnetic induction sensor 12 to detect the stylus S has been described. However, a capacitance sensor 11 may also be used to detect the stylus S. In this case, for example, detection of the stylus S can be performed using an active electrostatic method. When using the active electrostatic method, the distance information over which the pen signal can be received is greater than when using the electromagnetic induction method. Therefore, even without implementing the aforementioned design for parallel reception of pen signals, it is possible to detect the stylus S located approximately 5 cm away from the touch surface.

[0086] Label Description

[0087] 10 Electronic devices

[0088] 11, 12 Sensors

[0089] 13, 14 Sensor controller

[0090] 15 Microprocessor

[0091] 16 Machine Learning Department

[0092] 17 Host processor

[0093] 18, 20 Ministry of Communications

[0094] 21 Accelerometer

[0095] 22 Batteries

[0096] 30 Selection Circuit

[0097] 31 Receiving Department

[0098] 32 amplifiers

[0099] 33 High-speed analog-to-digital conversion (ADC) circuit

[0100] 34 Discrete Fourier Transform (DFT) Circuit

[0101] 37 Control Department

[0102] 38 Oscillator

[0103] 39 Current Driver

[0104] C Fixed capacitance capacitor

[0105] F finger

[0106] L coil

[0107] LC Toroidal Coil

[0108] S Pen

[0109] SW operation switch

[0110] VC variable capacitance capacitor

[0111] X1~X24 X-side toroidal coil

[0112] Y1~Y18 Y side ring coil

Claims

1. A position detection device comprising: a communication unit that receives acceleration information detected by the acceleration sensor from a stylus having a built-in acceleration sensor; and a controller that detects a first position indicating the position of the stylus pen within a touch surface and a second position indicating the position of a finger within the touch surface, and outputs the detected first and second positions, wherein the controller controls the output of the second position based on the acceleration information received by the communication unit. The controller releases the output restriction of the second position when the acceleration information received by the communication unit remains unchanged for a predetermined time period or longer.

2. The position detection device according to claim 1, wherein: The controller is configured to control output of the second position based on the acceleration information and the detected second position.

3. The position detection device according to claim 1 or 2, wherein: The acceleration sensor is a three-axis inertial sensor.

4. The position detection device according to claim 1, wherein: The controller is configured to control output of the second position based on the acceleration information and distance information indicating a distance between the stylus pen and the touch surface.

5. The position detection device according to claim 1 or 2, wherein: The controller includes a machine learning unit that receives as input at least one of the acceleration information, distance information indicating the distance between the stylus pen and the touch surface, and the second position, and outputs whether to limit output information indicating whether to limit output of the second position. The controller is configured to control output of the second position based on the restriction information output from the machine learning unit in response to input of the acceleration information, the distance information, and the second position.

6. The position detection device according to claim 1 or 2, wherein: The controller releases the output restriction of the second position when the communication unit continues not receiving the acceleration information for a predetermined time or longer.

7. The position detection device according to claim 1 or 2, wherein: The controller limits output of the second position when the stylus is not detected and the acceleration information indicates that the stylus is moving in a predetermined direction.

8. The position detection device according to claim 1 or 2, wherein: The controller limits output of the second position when a pen pressure value received from the stylus pen indicates that the tip of the stylus pen is in contact with the touch surface.

9. The position detection device according to claim 1 or 2, wherein: The sensor further includes a plurality of annular coils disposed within the touch surface. The controller includes a plurality of receiving parts. The controller selects at least a portion of the plurality of loop coils and connects the selected at least a portion of the loop coils to the different receiving units. The controller obtains reception strength of a pen signal received from the stylus pen at each of at least a portion of the loop coils based on output signals from the plurality of receiving units, and detects the first position based on the obtained reception strength.

10. The position detection device according to claim 9, wherein: The controller selects a portion of the discretely arranged loop coils among the plurality of loop coils, and connects each of the selected portion of the loop coils to the different receiving units. The controller obtains reception strengths of pen signals received from the stylus pen at each of the part of the loop coils based on output signals from the plurality of receiving units, and detects the first position based on the obtained reception strengths.

11. A position detection method, comprising causing a computer having a communication unit that receives acceleration information detected by a stylus having a built-in acceleration sensor to execute the following processing: detecting a first position indicating a position of the stylus pen within a touch surface and a second position indicating a position of a finger within the touch surface, and outputting the detected first position and second position; and controlling the output of the second position based on the acceleration information received by the communication unit, The computer is caused to execute processing for releasing the output restriction of the second position when the acceleration information received by the communication unit remains unchanged for a predetermined time or longer.

12. The position detection method according to claim 11, wherein: The computer is caused to execute a process of controlling output of the second position based on the acceleration information and the detected second position.

13. The position detection method according to claim 11 or 12, wherein: The acceleration sensor is a three-axis inertial sensor.

14. The position detection method according to claim 11, wherein: The computer is caused to execute a process of controlling output of the second position based on the acceleration information and distance information indicating the distance between the stylus pen and the touch surface.

15. The position detection method according to claim 11 or 12, wherein: The computer is caused to function as a machine learning unit that receives as input at least one of the acceleration information, the distance information indicating the distance between the stylus pen and the touch surface, and the second position, and outputs restriction information indicating whether to restrict output of the second position, and The computer is caused to execute processing for controlling output of the second position based on the restriction information output from the machine learning unit by inputting the acceleration information, the distance information, and the second position.

16. The position detection method according to claim 11 or 12, wherein: The computer is caused to execute processing for releasing the output restriction of the second position when a state in which the acceleration information is not received by the communication unit continues for a predetermined time or longer.

17. The position detection method according to claim 11 or 12, wherein: The computer is caused to execute processing for limiting output of the second position when the stylus pen is not detected and the acceleration information indicates that the stylus pen is moving in a predetermined direction.

18. The position detection method according to claim 11 or 12, wherein: The computer is caused to execute a process of limiting output of the second position when a pen pressure value received from the stylus pen indicates that the tip of the stylus pen is in contact with the touch surface.

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