Sensor controller, method and position detection device

Abstract

Provided are a sensor controller, a method, and a position detection device capable of suppressing interference between a pen detection signal and a pixel drive signal. A sensor controller according to the present invention is connected to an EMR sensor disposed so as to overlap with a display, in which an operation for detecting an electromagnetic induction pen using the EMR sensor is performed in synchronization with a touch detection operation for detecting a touch by a passive indicator within a panel surface of the display, and when the electromagnetic induction pen is detected, the EMR sensor performs an operation for detecting the electromagnetic induction pen using the EMR sensor. An action for detecting the electromagnetic induction pen using the EMR sensor is performed in synchronization with pixel driving of the display.

Description

Technical Field

[0001] The present invention relates to a sensor controller, a method, and a position detection device, and more particularly to a sensor controller connected to a sensor of an electromagnetic induction method (EMR method), a method executed by the sensor controller, and a position detection device including the sensor controller. Background Art

[0002] There is known a position detection device having a structure in which an EMR sensor and a touch sensor are overlapped and arranged with respect to a display for displaying an image or the like. The EMR sensor is used to detect an electromagnetic induction pen in a pen input by an electromagnetic induction method, and the touch sensor is used to detect a passive indicator in a touch input of a passive indicator such as a finger by a capacitance method. An example of such a position detection device is disclosed in Patent Document 1.

[0003] In addition, a position detection device having an EMR sensor and a touch sensor is disclosed in Patent Document 2. This position detection device is configured such that when an electromagnetic induction pen is detected by the EMR sensor, the position detection of the passive indicator by the touch sensor is stopped, and only the position detection of the pen by the EMR sensor is performed.

[0004] Prior Art Documents

[0005] Patent Documents

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2020-074245

[0007] Patent Document 2: Japanese Patent Application Laid-Open No. 2009-265759 Summary of the Invention

[0008] Problems to be Solved by the Invention

[0009] In a conventional position detection device of a type in which an EMR sensor, a touch sensor, and a display are overlapped and arranged, a detection operation of a passive indicator using the touch sensor (hereinafter referred to as "touch detection operation") is executed in synchronization with pixel driving of the display (hereinafter simply referred to as "pixel driving"), and an operation for detecting an electromagnetic induction pen using the EMR sensor (hereinafter referred to as "pen detection operation") is executed in synchronization with the touch detection operation. As a result, the pen detection operation is indirectly synchronized with the pixel driving.

[0010] In such a position detection device, if the position detection of the passive indicator described in Patent Document 2 stops, the pen detection operation cannot be synchronized with the touch detection operation. As a result, it also becomes impossible to synchronize with pixel driving, so there is a problem that interference may occur between the signal used for the pen detection operation (including the current signal for generating an alternating magnetic field and the current signal generated by the alternating magnetic field sent by the electromagnetic induction pen) and the pixel driving signal (including the gate signal and the source signal) used for the pixel driving of the display.

[0011] Here, in a conventional position detection device, there is a position detection device that generates a synchronization signal synchronized with pixel driving, and performs a touch detection operation synchronously with the synchronization signal, thereby synchronizing the touch detection operation with pixel driving. In addition, there is also a position detection device in which the generation of the synchronization signal does not stop even when the touch detection operation stops due to the detection of an electromagnetic induction pen. In such a position detection device, if the pen detection operation is performed synchronously with the above synchronization signal even during the stop of the touch detection operation, the pen detection operation (not actually performed) can be synchronized with the touch detection operation for the time being.

[0012] However, originally, in a conventional position detection device, the pen detection operation and the touch detection operation are synchronized to prevent the pen detection operation and the touch detection operation from becoming noise to each other. Therefore, during the stop of the touch detection operation, there is no need to synchronize with the touch detection operation originally. If so, it is preferable to directly synchronize the pen detection operation with pixel driving. By doing so, the effect of suppressing the interference between the signal used for the pen detection operation and the pixel driving signal used for the pixel driving of the display can be maximized. Nevertheless, according to the above method, since the pen detection operation is also synchronized with the touch detection operation during the stop of the touch detection operation, the synchronization between the pen detection operation and pixel driving becomes an indirect synchronization, and the interference suppression effect that should originally be obtained cannot be obtained sufficiently.

[0013] Therefore, one object of the present invention is to provide a sensor controller, a method, and a position detection device that can reliably suppress the interference between the signal used for the pen detection operation and the pixel driving signal used for the pixel driving of the display.

[0014] Means for Solving the Problem

[0015] The sensor controller of the present invention is connected to an EMR sensor disposed overlapping with a display. Among them, an operation for detecting an electromagnetic induction pen using the EMR sensor is performed synchronously with a touch detection operation for detecting a touch of a passive indicator in the panel surface of the display. When the electromagnetic induction pen is detected, an operation for detecting the electromagnetic induction pen using the EMR sensor is performed synchronously with the pixel driving of the display.

[0016] The method of the present invention is executed by a sensor controller connected to an EMR sensor disposed overlapping with a display. Among them, it includes: a step of performing an operation for detecting an electromagnetic induction pen using the EMR sensor synchronously with a touch detection operation for detecting a touch of a passive indicator in the panel surface of the display; and a step of performing an operation for detecting the electromagnetic induction pen using the EMR sensor synchronously with the pixel driving of the display when the electromagnetic induction pen is detected.

[0017] The position detection device of the present invention includes: a display; an EMR sensor and a touch sensor disposed overlapping with the display; and a sensor controller respectively connected to the EMR sensor and the touch sensor. Among them, the sensor controller performs an operation for detecting an electromagnetic induction pen using the EMR sensor synchronously with a touch detection operation using the touch sensor for detecting a touch of a passive indicator in the panel surface of the display. When the electromagnetic induction pen is detected, an operation for detecting the electromagnetic induction pen using the EMR sensor is performed synchronously with the pixel driving of the display.

[0018] Advantages of the Invention

[0019] According to the present invention, since the pen detection operation is performed synchronously with the touch detection operation when the touch detection operation is performed, and the pen detection operation is performed synchronously with the pixel driving of the display when the touch detection operation is not performed, it is possible to reliably suppress the interference between the signal used for the pen detection operation and the signal used for the pixel driving of the display. Description of the Drawings

[0020] Figure 1 It is a diagram showing the structure of a position detection system 1 according to a first embodiment of the present invention.

[0021] Figure 2 It is a diagram showing the internal structure of a sensor controller 30 according to a first embodiment of the present invention.

[0022] Figure 3 It is a timing diagram showing various signals, operations, and operation modes related to a first embodiment of the present invention and the sensor controller 30.

[0023] Figure 4 It is a flowchart showing the processing of the touch detection operation control circuit 20 according to the first embodiment of the present invention.

[0024] Figure 5 It is a flowchart showing the processing of the pen detection operation control circuit 21 according to the first embodiment of the present invention.

[0025] Figure 6 It is a flowchart showing the processing of the pen detection operation control circuit 21 according to the first embodiment of the present invention.

[0026] Figure 7 It is a flowchart showing the processing of the pen detection operation control circuit 21 according to the first embodiment of the present invention.

[0027] Figure 8 It is a diagram showing the internal structure of the sensor controller 30 according to the second embodiment of the present invention.

[0028] Figure 9 It is a timing diagram showing each signal related to the second embodiment of the present invention and the operation and operation mode of the sensor controller 30.

[0029] Figure 10 It is a flowchart showing the processing of the touch detection operation control circuit 20 according to the second embodiment of the present invention.

[0030] Figure 11 It is a flowchart showing the processing of the pen detection operation control circuit 21 according to the second embodiment of the present invention.

[0031] Figure 12 It is a flowchart showing the processing of the pen detection operation control circuit 21 according to the second embodiment of the present invention.

[0032] Figure 13 It is a diagram showing the internal structure of the sensor controller 30 according to the third embodiment of the present invention.

[0033] Figure 14 It is a timing diagram showing each signal related to the third embodiment of the present invention and the operation and operation mode of the sensor controller 30.

[0034] Figure 15 It is a flowchart showing the processing of the pen detection operation control circuit 21 according to the third embodiment of the present invention.

[0035] Figure 16 It is a flowchart showing the processing of the pen detection operation control circuit 21 according to the third embodiment of the present invention.

[0036] Figure 17 It shows Figure 16Flowchart showing the specific content of the EMR-HSYNC activation process. Detailed implementation

[0037] Hereinafter, with reference to the accompanying drawings, embodiments of the present invention will be described in detail.

[0038] Figure 1 FIG. 1 is a diagram showing the configuration of a position detection system 1 according to a first embodiment of the present invention. As shown in this figure, the position detection system 1 is configured to include an electromagnetic induction pen 2 and a position detection device 3. Among them, the electromagnetic induction pen 2 is a pen that supports position detection in the EMR method, and is configured to have a resonance circuit including a coil and a capacitor inside.

[0039] The position detection device 3 is a computer that supports pen input in the EMR method and touch input in the capacitive touch method, and is configured to include a sensor controller 30, a host processor 31, a touch sensor 41, a display 42, and an EMR sensor 43. In a typical example, the position detection device 3 is a tablet terminal or a notebook computer that supports pen input and touch input.

[0040] The touch sensor 41, the display 42, and the EMR sensor 43 are arranged overlappingly in this order from the panel surface 3a side of the position detection device 3. Thus, the panel surface 3a is the display surface of the display 42 and also serves as a touch surface for the user to perform pen input and touch input.

[0041] The touch sensor 41 is a sensor used to detect a passive indicator using the capacitive touch method, and is configured to have a plurality of first linear electrodes that extend in a first direction within the panel surface 3a and are arranged at equal intervals in a second direction orthogonal to the first direction within the panel surface 3a, and a plurality of second linear electrodes that extend in the second direction and are arranged at equal intervals in the first direction. The plurality of first linear electrodes and the plurality of second linear electrodes are respectively connected to a touch detection circuit 22 (described later) within the sensor controller 30.

[0042] The EMR sensor 43 is a sensor used to detect the electromagnetic induction pen 2, and is configured to have a plurality of first toroidal coils that extend in the first direction and are arranged in the second direction, and a plurality of second toroidal coils that extend in the second direction and are arranged in the first direction. The plurality of first toroidal coils and the plurality of second toroidal coils are respectively connected to a pen detection circuit 23 (described later) within the sensor controller 30.

[0043] The sensor controller 30 is an integrated circuit having a function of deriving the position of a passive indicator within the panel surface 3a using the touch sensor 41 and a function of deriving the position of the electromagnetic induction pen 2 within the panel surface 3a using the EMR sensor 43. The sensor controller 30 is configured to also have a function of receiving data transmitted by the electromagnetic induction pen 2. The position derived by the sensor controller 30 and the received data are successively supplied to the host processor 31.

[0044] The host processor 31 is the central processing unit of the position detection device 3 and is connected to the display 42 and the sensor controller 30. The host processor 31 functions to execute the operating system and various application programs of the position detection device 3 by executing a program read from a memory (not shown). Among the processes executed by the host processor 31 according to the program, there are processes such as generating an image signal and supplying it to the display 42, and various processes using the position and data supplied from the sensor controller 30. Among the various processes using the position and data, for example, there are the movement of the cursor displayed by the display 42 on the panel surface 3a, the generation of stroke data indicating the trajectory of the electromagnetic induction pen 2 within the panel surface 3a, etc. Among them, regarding the stroke data, the host processor 31 also performs processes such as rendering and displaying the generated stroke data, generating and recording digital ink containing the generated stroke data, and transmitting the generated digital ink to an external device according to the user's instruction.

[0045] The display 42 is a display device having a plurality of pixels arranged in a matrix and drive circuits for driving these plurality of pixels respectively. In a specific example, the display 42 can be composed of a liquid crystal display, an organic EL display, an electronic paper, etc. The drive circuit of the display 42 functions to display the image signal on the panel surface 3a by driving each pixel according to the image signal supplied from the host processor 31.

[0046] Figure 2 is a diagram showing the internal structure of the sensor controller 30. As shown in this diagram, the sensor controller 30 is configured to include a touch detection operation control circuit 20, a pen detection operation control circuit 21, a pen detection circuit 23, and a touch detection circuit 22. In addition, Figure 3 is a timing diagram showing each signal, the operation, and the operation mode of the sensor controller 30 according to the present embodiment. Hereinafter, while referring to these diagrams, the structure and operation of the sensor controller 30 will be described in detail.

[0047] The touch detection circuit 22 is a circuit that performs the above-described touch detection operation using the touch sensor 41. Specifically, the touch detection circuit 22 separately sends mutually different touch detection signals to the plurality of first linear electrodes in the touch sensor 41 and separately receives them at the plurality of second linear electrodes. Further, it is configured to derive the position of the passive indicator in the panel surface 3a based on the reception result.

[0048] The touch detection operation control circuit 20 is a circuit that controls the timing of the above-described operation of the touch detection circuit 22. Specifically, the touch detection operation control circuit 20 is configured to generate a touch detection operation synchronization signal TP_VSYNC indicating the operation timing of the touch detection operation and supply it to the touch detection circuit 22. As Figure 3 shown, the touch detection circuit 22 is configured to perform one touch detection operation each time the touch detection operation synchronization signal TP_VSYNC is activated (indicated as “TS” in Figure 3 ).

[0049] Here, the host processor 31 is configured to generate a vertical synchronization signal DISP_VSYNC indicating the start timing of the frame period F, which is the period for displaying one frame, and a horizontal synchronization signal DISP_HSYNC indicating the switching timing of the video lines, and supply them to the display 42 together with the video signal. The drive circuit of the above-described display 42 is configured to drive a plurality of pixels at the timings of these signals. As a result, the image displayed on the panel surface 3a by the display 42 is updated at the frame period F.

[0050] As Figure 3 indicated by the dashed arrow in, the touch detection operation control circuit 20 is configured to activate the touch detection operation synchronization signal TP_VSYNC in synchronization with the vertical synchronization signal DISP_VSYNC generated by the host processor 31. Thereby, the touch detection circuit 22 performs the touch detection operation in synchronization with the pixel drive of the display 42.

[0051] The pen detection circuit 23 is a circuit that performs the above-described pen detection operation using the EMR sensor 43. Specifically, the pen detection circuit 23 supplies an alternating current to one of the plurality of first toroidal coils in the EMR sensor 43 for a specified period to generate an alternating magnetic field on the panel surface 3a. When the coil constituting the resonance circuit of the electromagnetic induction pen 2 enters this alternating magnetic field, an electromotive force is generated at both ends of the coil, and the capacitor constituting the resonance circuit together with the coil is charged. When the supply of the alternating current is stopped by the pen detection circuit 23 and the alternating magnetic field on the panel surface 3a disappears, an alternating current flows through the coil of the resonance circuit by the electric power stored in the capacitor, and an alternating magnetic field is sent out. The pen detection circuit 23 detects the alternating current (pen signal) generated by this alternating magnetic field at each of the plurality of second toroidal coils and obtains the detection intensity thereof. The pen detection circuit 23 is configured to obtain the distribution of the detection intensity within the panel surface 3a by performing the above processing for each of the plurality of first toroidal coils, and to derive the position of the electromagnetic induction pen 2 within the panel surface 3a based on the result.

[0052] The pen detection circuit 23 is configured to perform the above-described pen detection operation by any one of global scanning, idle scanning, and sector scanning under the control of the pen detection operation control circuit 21 described later.

[0053] Global scanning is a pen detection operation performed using all of the first toroidal coils and all of the second toroidal coils in the EMR sensor 43. In Figure 3 this, global scanning is denoted as "GS". According to global scanning, the electromagnetic induction pen 2 can be detected throughout the panel surface 3a. On the other hand, it takes a relatively long time to perform one pen detection operation.

[0054] Idle scanning is a pen detection operation performed when the host processor 31 is in an idle state. It is the same as global scanning in that it is performed using all of the first toroidal coils and all of the second toroidal coils in the EMR sensor 43, but it is different from global scanning in that the pen detection operation is performed at a lower frequency than global scanning. According to idle scanning, the electromagnetic induction pen 2 can be detected only at a lower frequency than global scanning, but the power consumption of the pen detection operation can be reduced. It should be noted that when the host processor 31 in the idle state operates at a lower clock than the normal state, idle scanning is performed at a lower clock (i.e., it takes a longer time) than global scanning.

[0055] Sector scanning is a pen detection operation used to update the position of the detected electromagnetic induction pen 2 when the electromagnetic induction pen 2 has already been detected. It is performed using only a specified number of first toroidal coils and second toroidal coils in the vicinity of the previously derived position among the plurality of first toroidal coils and the plurality of second toroidal coils in the EMR sensor 43. In Figure 3In this case, the sector scan is denoted as "SS". According to the sector scan, it is not possible to detect the electromagnetic induction pen 2 as a whole within the panel surface 3a, but it is possible to complete one pen detection operation in a relatively short time.

[0056] In the following description, the operation modes of the pen detection circuit 23 that perform the global scan, the idle scan, and the sector scan are respectively referred to as the global scan mode, the idle scan mode, and the sector scan mode.

[0057] The pen detection operation control circuit 21 is a circuit that controls the timing of the pen detection operation performed by the pen detection circuit 23 and controls the operation mode of the pen detection circuit 23. Specifically, the pen detection operation control circuit 21 is configured to selectively generate either the pen detection operation synchronization signal INT_VS_EMR_G indicating the operation timing of the pen detection operation in the global scan or the pen detection operation synchronization signal INT_VS_EMR_S indicating the operation timing of the pen detection operation in the sector scan and supply it to the pen detection circuit 23. As Figure 3 shown, the pen detection circuit 23 is configured to perform one global scan each time the pen detection operation synchronization signal INT_VS_EMR_G is activated, and perform one sector scan each time the pen detection operation synchronization signal INT_VS_EMR_S is activated. The pen detection operation control circuit 21 causes the pen detection circuit 23 to operate in the global scan mode by activating the pen detection operation synchronization signal INT_VS_EMR_G at a relatively high frequency, causes the pen detection circuit 23 to operate in the idle scan mode by activating the pen detection operation synchronization signal INT_VS_EMR_G at a relatively low frequency, and causes the pen detection circuit 23 to operate in the sector scan mode by activating the pen detection operation synchronization signal INT_VS_EMR_S.

[0058] Here, the host processor 31 stores a status flag IDLE indicating whether it is in an idle state. The pen detection operation control circuit 21 determines whether the host processor 31 is in an idle state by referring to this status flag IDLE. When it is determined that the host processor 31 is in an idle state, the pen detection operation control circuit 21 causes the pen detection circuit 23 to operate in the idle scan mode by activating the pen detection operation synchronization signal INT_VS_EMR_G at a relatively low frequency. On the other hand, when it is determined that the host processor 31 is not in an idle state, the pen detection operation control circuit 21 causes the pen detection circuit 23 to operate in the global scan mode by activating the pen detection operation synchronization signal INT_VS_EMR_G at a relatively high frequency.

[0059] The pen detection operation control circuit 21 is configured as Figure 3As shown by the dashed arrow in the figure, as a principle, the activation of the synchronization signal INT_VS_EMR_G for the pen detection operation is synchronized with the synchronization signal TP_VSYNC for the touch detection operation generated by the touch detection operation control circuit 20. On the other hand, after the electromagnetic induction pen 2 is detected, the activation of the synchronization signals INT_VS_EMR_G and INT_VS_EMR_S for the pen detection operation is synchronized with the vertical synchronization signal DISP_VSYNC generated by the host processor 31. It should be noted that at the timing when the synchronization signal INT_VS_EMR_S for the pen detection operation is activated, the electromagnetic induction pen 2 is surely detected. Therefore, the synchronization signal INT_VS_EMR_S for the pen detection operation is not activated synchronously with the synchronization signal TP_VSYNC for the touch detection operation. Thus, before the electromagnetic induction pen 2 is detected, the pen detection circuit 23 performs the pen detection operation (specifically, global scanning or idle scanning) synchronously with the touch detection operation. On the other hand, when the electromagnetic induction pen 2 is detected by this pen detection operation, the pen detection operation (specifically, global scanning or sector scanning) is performed synchronously with the pixel driving of the display 42.

[0060] The pen detection operation control circuit 21 performs such an operation because: in the present embodiment, when the electromagnetic induction pen 2 is detected by the pen detection circuit 23, the touch detection operation control circuit 20 stops generating the synchronization signal TP_VSYNC for the touch detection operation. This stop is performed to prevent the touch detection operation from being performed during the pen input based on the electromagnetic induction pen 2 and, as a result, noise from being mixed into the stroke data. The pen detection circuit 23 stores a status flag PFLG indicating whether the electromagnetic induction pen 2 is detected. The touch detection operation control circuit 20 is configured to determine whether the electromagnetic induction pen 2 is detected by referring to this status flag PFLG and decide whether to stop generating the synchronization signal TP_VSYNC for the touch detection operation according to the result.

[0061] In Figure 3An example is shown in which the electromagnetic induction pen 2 is detected at time t1 when the pen detection circuit 23 operates in the idle scan mode. In this case, immediately after detecting the electromagnetic induction pen 2, the pen detection operation control circuit 21 temporarily operates the pen detection circuit 23 in the global scan mode. That is, the pen detection operation control circuit 21 activates the synchronization signal INT_VS_EMR_G for the pen detection operation in synchronization with the vertical synchronization signal DISP_VSYNC. As described above, the idle scan is sometimes executed at a lower clock than the global scan. As a result, the position of the electromagnetic induction pen 2 detected in the idle scan may have lower accuracy than the position of the electromagnetic induction pen 2 detected in the global scan. By temporarily operating the pen detection circuit 23 in the global scan in this way, the position of the electromagnetic induction pen 2 can be detected with the accuracy of the normal global scan. After detecting the position of the electromagnetic induction pen 2 through the global scan, the pen detection operation control circuit 21 activates the synchronization signal INT_VS_EMR_S for the pen detection operation in synchronization with the vertical synchronization signal DISP_VSYNC. Thereby, the pen detection circuit 23 can gradually update the position of the electromagnetic induction pen 2.

[0062] Figure 4 is a flowchart showing the processing of the touch detection operation control circuit 20, Figures 5 - 7 is a flowchart showing the processing of the pen detection operation control circuit 21. Hereinafter, while referring to these Figure 1 the operation of the sensor controller 30 will be described in more detail again.

[0063] First, referring to Figure 4 , the touch detection operation control circuit 20 determines whether the pen detection circuit 23 has detected the electromagnetic induction pen 2 by referring to the status flag PFLG stored in the pen detection circuit 23 (step S1). If it is determined in this determination that the pen has been detected, the touch detection operation control circuit 20 then continues the determination process of step S1. In this case, the synchronization signal TP_VSYNC for the touch detection operation is not activated, and the touch detection operation is not performed by the touch detection circuit 22.

[0064] On the other hand, if it is determined in step S1 that the pen has not been detected, the touch detection operation control circuit 20 performs a process of activating the synchronization signal TP_VSYNC for the touch detection operation twice in synchronization with the vertical synchronization signal DISP_VSYNC (steps S2 to S5).

[0065] Specifically, the touch detection operation control circuit 20 determines whether the vertical synchronization signal DISP_VSYNC has been activated (step S2). If it is determined that it has not been activated, the process of step S2 is repeated. On the other hand, if it is determined that it has been activated, the synchronization signal TP_VSYNC for touch detection operation is activated (step S3). After that, it is determined whether a specified time has elapsed (step S4). If it is determined that the specified time has elapsed, the synchronization signal TP_VSYNC for touch detection operation is activated again (step S5).

[0066] After the end of step S5, the touch detection operation control circuit 20 returns to step S1 and repeats the above process. Thus, on the condition that the pen detection circuit 23 does not detect the electromagnetic induction pen 2, two touch detection operations are performed in each frame period F as shown Figure 3 below.

[0067] Next, referring to Figure 5 , the pen detection operation control circuit 21 determines which of the idle state and the normal state the host processor 31 is in by referring to the status flag IDLE stored in the host processor 31 (step S10). If it is determined in this determination that it is the normal state, the pen detection operation control circuit 21 proceeds to Figure 6 step S20 shown below and continues the process.

[0068] On the other hand, when the pen detection operation control circuit 21 determines in step S10 that it is in the idle state, in order to make the pen detection circuit 23 operate in the idle scan mode, at a ratio of once every three activations of the synchronization signal TP_VSYNC for touch detection operation, the process of activating the synchronization signal INT_VS_EMR_G for pen detection operation synchronously with the synchronization signal TP_VSYNC for touch detection operation is performed (steps S11 to S15).

[0069] Specifically, the pen detection operation control circuit 21 first sets the variable N as a counter to 0 (step S11), and repeats the process of determining whether the synchronization signal TP_VSYNC for touch detection operation has been activated until the synchronization signal TP_VSYNC for touch detection operation is activated (step S12). If it is determined in this determination that the synchronization signal TP_VSYNC for touch detection operation has been activated, the pen detection operation control circuit 21 determines whether the variable N is 2 or more (step S13). If it is 2 or more, the synchronization signal INT_VS_EMR_G for pen detection operation is activated (step S15). On the other hand, if it is not 2 or more, 1 is added to N (step S14), and then it returns to step S12. When the synchronization signal INT_VS_EMR_G for pen detection operation is activated in step S15, the pen detection circuit 23 performs a global scan once.

[0070] In step S15, the pen detection operation control circuit 21 that activates the synchronization signal INT_VS_EMR_G for the pen detection operation determines whether the electromagnetic induction pen 2 is detected (step S16). The result of this determination becomes affirmative when the electromagnetic induction pen 2 is detected by the global scan executed according to the synchronization signal INT_VS_EMR_G for the pen detection operation activated in step S15, and becomes negative otherwise.

[0071] When a negative result is obtained in step S16, the pen detection operation control circuit 21 determines again whether the host processor 31 is in an idle state or a normal state by referring again to the status flag IDLE stored in the host processor 31 (step S17). When an affirmative result is obtained in step S16 and when the pen detection operation control circuit 21 obtains a determination result of the normal state in step S17, it proceeds to Figure 6 step S20 shown and continues the process. On the other hand, when the pen detection operation control circuit 21 obtains a determination result of the idle state in step S17, it returns to step S11 and continues the process.

[0072] Next, referring to Figure 6 , the pen detection operation control circuit 21 that migrates to step S20, in order to operate the pen detection circuit 23 in the global scan mode, performs a process of activating the synchronization signal INT_VS_EMR_G for the pen detection operation synchronously with the vertical synchronization signal DISP_VSYNC every time the vertical synchronization signal DISP_VSYNC is activated (steps S20 to S23).

[0073] Specifically, the pen detection operation control circuit 21 repeatedly performs a process of determining whether the vertical synchronization signal DISP_VSYNC has been activated until the vertical synchronization signal DISP_VSYNC is activated (step S20). When it is determined in this determination that the vertical synchronization signal DISP_VSYNC has been activated, the pen detection operation control circuit 21 activates the synchronization signal INT_VS_EMR_G for the pen detection operation (step S21). By this activation, the pen detection circuit 23 executes the global scan once.

[0074] After activating the synchronization signal INT_VS_EMR_G for the pen detection operation in step S21, the pen detection operation control circuit 21 performs a process related to Figure 5The same processing as steps S16 and S17 shown above (steps S22 and S23). That is, the pen detection operation control circuit 21 determines whether the electromagnetic induction pen 2 is detected as a result of the activation in step S21 (step S22). If a negative result is obtained, it is determined whether the host processor 31 is in the idle state or the normal state by referring to the status flag IDLE stored in the host processor 31 (step S23). If the pen detection operation control circuit 21 obtains an affirmative result in step S22, it proceeds to Figure 7 step S30 and continues the processing. In addition, when the pen detection operation control circuit 21 obtains a determination result of the normal state in step S23 executed after receiving a negative result in step S22, it returns to step S20 and continues the processing. When a determination result of the idle state is obtained, it proceeds to Figure 5 step S11 and continues the processing.

[0075] Next, referring to Figure 7 , the pen detection operation control circuit 21 that migrates to step S30 activates the synchronization signal INT_VS_EMR_S for pen detection operation twice in synchronization with the vertical synchronization signal DISP_VSYNC every time the vertical synchronization signal DISP_VSYNC is activated in order to make the pen detection circuit 23 operate in a fan-shaped scanning mode (steps S30 to S33).

[0076] Specifically, the pen detection operation control circuit 21 determines whether the vertical synchronization signal DISP_VSYNC has been activated (step S30). If it is determined that it has not been activated, the process of step S30 is repeated. On the other hand, if it is determined that it has been activated, the synchronization signal INT_VS_EMR_S for pen detection operation is activated (step S31). After that, it is determined whether a specified time has elapsed (step S32). If it is determined that the specified time has elapsed, the synchronization signal INT_VS_EMR_S for pen detection operation is activated again (step S33).

[0077] After step S33 ends, the pen detection operation control circuit 21 determines whether the electromagnetic induction pen 2 is detected as a result of the activation in step S31 or step S33 (step S34). If a negative result is obtained, it proceeds to step S20 to make the pen detection circuit 23 perform a global scan. On the other hand, if an affirmative result is obtained in step S34, the pen detection operation control circuit 21 returns to step S30 and repeats the above process. Thus, during the period when the pen detection circuit 23 detects the electromagnetic induction pen 2, Figure 3 two fan-shaped scans are performed in each frame period F shown above.

[0078] As described above, according to the sensor controller 30 of the present embodiment, before the electromagnetic induction pen 2 is detected, a touch detection operation is performed synchronously with the pixel driving of the display 42, and a pen detection operation is performed synchronously with the touch detection operation. On the other hand, when it is detected that the electromagnetic induction pen 2 is detected and the touch detection operation is stopped, the pen detection operation is performed synchronously with the pixel driving of the display 42. Therefore, it is possible to reliably suppress the interference between the signal used for the pen detection operation and the signal used for the pixel driving of the display 42.

[0079] Next, the position detection system 1 of the second embodiment of the present invention will be described. The position detection system 1 of the present embodiment is different from the position detection system 1 of the first embodiment in terms of the internal processing of the sensor controller 30, and is the same as the position detection system 1 of the first embodiment in other points. Hereinafter, the differences from the position detection system 1 of the first embodiment will be described.

[0080] Figure 8 is a diagram showing the internal structure of the sensor controller 30 of the present embodiment. By comparing this diagram with Figure 2 it can be understood that the pen detection operation control circuit 21 of the present embodiment is configured to generate a pen detection operation synchronization signal EMR_VSYNC and a touch detection enable signal Enable_TP instead of the pen detection operation synchronization signals INT_VS_EMR_G and INT_VS_EMR_S, supply both of them to the pen detection circuit 23, and supply only the touch detection enable signal Enable_TP to the touch detection circuit 22. It should be noted that in the present embodiment, the status flags IDLE and PFLG are not used.

[0081] The pen detection circuit 23 of the present embodiment is configured to perform one global scan each time the pen detection operation synchronization signal EMR_VSYNC is activated when the touch detection enable signal Enable_TP is activated, and perform one sector scan each time the pen detection operation synchronization signal EMR_VSYNC is activated when the touch detection enable signal Enable_TP is deactivated. In the present embodiment, idle scanning is not used.

[0082] The touch detection operation control circuit 20 of the present embodiment is configured to generate a synchronization signal TP_VSYNC for touch detection operation in synchronization with the vertical synchronization signal DISP_VSYNC regardless of whether the electromagnetic induction pen 2 is detected by the pen detection circuit 23. On the other hand, the touch detection circuit 22 of the present embodiment is configured to perform a touch detection operation according to the activation of the synchronization signal TP_VSYNC for touch detection operation when the touch detection enable signal Enable_TP is activated, and on the other hand, when the touch detection enable signal Enable_TP is deactivated, no touch detection operation is performed regardless of the state of the synchronization signal TP_VSYNC for touch detection operation.

[0083] Figure 9 It is a timing chart showing the operations and operation modes of the respective signals and the sensor controller 30 according to the present embodiment. Figure 9 The touch detection signal TP_TX shown is a signal that the touch detection circuit 22 separately transmits to a plurality of first linear electrodes in the touch sensor 41 in order to derive the position of the passive indicator. Figure 9 The shaded area shown indicates that the touch detection signal TP_TX is being transmitted. In addition, the EMR transmission signal EMR_TX is an alternating current supplied by the pen detection circuit 23 to one of the plurality of first toroidal coils in the EMR sensor 43. Figure 9 The shaded area shown indicates that the EMR transmission signal EMR_TX is being supplied. The EMR reception signal EMR_RX representatively shows the alternating current with the highest detection intensity among the alternating currents separately detected by the pen detection circuit 23 at the plurality of second toroidal coils in the EMR sensor 43. Figure 9 The shaded area shown indicates the detection intensity of the EMR reception signal EMR_RX. The EMR position derivation processing state EMR_CALC shows the derivation state of the position of the electromagnetic induction pen 2 by the pen detection circuit 23. Figure 9 The shaded area shown indicates that the derivation is being executed. These points are the same in the following Figure 14 as well.

[0084] As Figure 9As shown, the pen detection operation control circuit 21 of the present embodiment is configured to activate the touch detection enable signal Enable_TP according to the detection of the electromagnetic induction pen 2 at time t1, and restore the touch detection enable signal Enable_TP to inactive according to the non-detection of the electromagnetic induction pen 2 at time t2 (i.e., loss of the electromagnetic induction pen 2). In addition, the pen detection operation control circuit 21 is configured to activate the pen detection operation synchronization signal EMR_VSYNC synchronously with the touch detection operation synchronization signal TP_VSYNC generated by the touch detection operation control circuit 20 as a principle. On the other hand, during the period when the electromagnetic induction pen 2 is detected ( Figure 9 between time t1 and time t2 in), each time the vertical synchronization signal DISP_VSYNC generated by the host processor 31 is activated, the pen detection operation synchronization signal EMR_VSYNC is activated three times. Thus, when the pen detection circuit 23 does not detect the electromagnetic induction pen 2, it performs the pen detection operation (specifically, global scanning) synchronously with the touch detection operation. On the other hand, when the electromagnetic induction pen 2 is detected by this pen detection operation, each time the vertical synchronization signal DISP_VSYNC is activated, it performs the pen detection operation three times (specifically, sector scanning) synchronously with the pixel driving of the display 42. It should be noted that the pen detection circuit 23 may also perform one sector scan by dispersing it into these three pen detection operations. In addition, when the pen detection circuit 23 does not detect the electromagnetic induction pen 2, the touch detection circuit 22 performs the touch detection operation synchronously with the pixel driving of the display 42, and when the pen detection circuit 23 detects the electromagnetic induction pen 2, it does not perform the touch detection operation.

[0085] In the present embodiment, different from the first embodiment, when the pen detection circuit 23 detects the electromagnetic induction pen 2, the touch detection operation control circuit 20 does not stop generating the touch detection operation synchronization signal TP_VSYNC. Nevertheless, the pen detection operation control circuit 21 performs the above-described operation because: when performing the touch detection operation, in order to avoid the touch detection operation and the pen detection operation from becoming noise to each other, it is necessary to perform the pen detection operation directly synchronously with the touch detection operation. On the other hand, when the touch detection operation is not performed, there is no such need. Rather, in order to avoid the pixel driving and the pen detection operation from becoming noise to each other, it becomes preferable to perform the pen detection operation directly synchronously with the pixel driving of the display 42.

[0086] Figure 10 is a flowchart showing the processing of the touch detection operation control circuit 20 of the present embodiment, Figure 11 and Figure 12It is a flowchart showing the processing of the pen detection operation control circuit 21 of the present embodiment. Hereinafter, while referring to these figures, the operation of the sensor controller 30 of the present embodiment will be described in more detail again.

[0087] First, refer to Figure 10 , the operation of the touch detection operation control circuit 20 of the present embodiment is the same as that of the touch detection operation control circuit 20 of the first embodiment shown in Figure 4 except for the determination process of the status flag PFLG (steps S40 to S43). Therefore, according to the touch detection operation control circuit 20 of the present embodiment, regardless of whether the pen detection circuit 23 detects the electromagnetic induction pen 2, an execution instruction for the touch detection operation is supplied to the touch detection circuit 22 twice for each frame period F shown in Figure 9 . However, as described above, the touch detection circuit 22 of the present embodiment does not perform the touch detection operation when the touch detection enable signal Enable_TP is inactive. As a result, the touch detection operation is not executed when the pen detection circuit 23 detects the electromagnetic induction pen 2.

[0088] Next, refer to Figure 11 , the pen detection operation control circuit 21 of the present embodiment first activates the touch detection enable signal Enable_TP (step S50), creates a state in which the touch detection circuit 22 performs the touch detection operation, and makes the pen detection circuit 23 enter the global scan mode. Next, the pen detection operation control circuit 21 repeatedly performs the process of determining whether the synchronization signal TP_VSYNC for the touch detection operation has been activated until the synchronization signal TP_VSYNC for the touch detection operation is activated (step S51), and activates the synchronization signal EMR_VSYNC for the pen detection operation according to the determination that the synchronization signal TP_VSYNC for the touch detection operation has been activated (step S52). After that, the pen detection operation control circuit 21 determines whether the electromagnetic induction pen 2 is detected by the pen detection circuit 23 (step S53). If it is determined that it is not detected, the process returns to step S51. On the other hand, if it is determined that it is detected, the process moves to Figure 12 step S60.

[0089] Next, refer to Figure 12, the pen detection operation control circuit 21 that migrates to step S60 creates a state in which the touch detection operation is not performed by the touch detection circuit 22 by making the touch detection enable signal Enable_TP inactive (step S60), and causes the pen detection circuit 23 to enter the fan-shaped scanning mode. Next, the pen detection operation control circuit 21 determines whether the vertical synchronization signal DISP_VSYNC has been activated (step S61). If it is determined that it has not been activated, the process of step S61 is repeated. On the other hand, if it is determined that it has been activated, the synchronization signal EMR_VSYNC for the pen detection operation is activated (step S62). After that, it is determined whether a predetermined time has elapsed (step S63). If it is determined that the predetermined time has elapsed, the synchronization signal EMR_VSYNC for the pen detection operation is activated again (step S64). Then, the pen detection operation control circuit 21 further determines whether a predetermined time has elapsed (step S65). If it is determined that the predetermined time has elapsed, the synchronization signal EMR_VSYNC for the pen detection operation is activated for the third time (step S66). Thus, every time the vertical synchronization signal DISP_VSYNC is activated, the pen detection circuit 23 performs the detection operation on the electromagnetic induction pen 2 three times.

[0090] After the end of step S66, the pen detection operation control circuit 21 determines whether the electromagnetic induction pen 2 has been detected as a result of the activation in steps S62, S64, and S66 (step S67). If a negative result is obtained, the touch detection enable signal Enable_TP is activated (step S68), and the process proceeds to Figure 11 step S51. On the other hand, if a positive result is obtained in step S67, the pen detection operation control circuit 21 returns to step S61 and repeats the above process.

[0091] As described above, according to the sensor controller 30 of the present embodiment, before the electromagnetic induction pen 2 is detected, the touch detection operation is performed in synchronization with the pixel driving of the display 42, and the pen detection operation is performed in synchronization with the touch detection operation. On the other hand, when it is received that the electromagnetic induction pen 2 has been detected and the touch detection operation has stopped, although the touch detection operation control circuit 20 has not stopped generating the synchronization signal TP_VSYNC for the touch detection operation, the pen detection operation is also performed in synchronization with the pixel driving of the display 42. Therefore, it is possible to reliably suppress the interference between the signal used for the pen detection operation and the signal used for the pixel driving of the display 42.

[0092] Next, the position detection system 1 according to the third embodiment of the present invention will be described. The position detection system 1 of the present embodiment is different from the position detection system 1 of the second embodiment in that the synchronization signal EMR_HSYNC for pen detection operation synchronized with the horizontal synchronization signal DISP_HSYNC is used, and is the same as the position detection system 1 of the second embodiment in other points. Hereinafter, the differences from the position detection system 1 of the second embodiment will be focused on and described.

[0093] Figure 13 This is a diagram showing the internal structure of the sensor controller 30 of the present embodiment. By comparing this diagram with Figure 8 it can be understood that the pen detection operation control circuit 21 of the present embodiment is configured to supply the synchronization signal EMR_HSYNC for pen detection operation to the pen detection circuit 23 instead of the synchronization signal EMR_VSYNC for pen detection operation. In the present embodiment, the synchronization signal EMR_VSYNC for pen detection operation is only used as an internal signal of the pen detection operation control circuit 21 and is not supplied to the pen detection circuit 23.

[0094] The pen detection circuit 23 of the present embodiment is configured to perform one global scan each time the synchronization signal EMR_HSYNC for pen detection operation is activated when the touch detection enable signal Enable_TP is activated, and to perform one sector scan each time the synchronization signal EMR_HSYNC for pen detection operation is activated when the touch detection enable signal Enable_TP is deactivated.

[0095] Figure 14is a timing chart showing each signal and the operation and operation mode of the sensor controller 30 according to the present embodiment. As shown in this figure, the pen detection operation control circuit 21 of the present embodiment is configured such that when the electromagnetic induction pen 2 is not detected, the pen detection operation synchronization signal EMR_HSYNC is activated twice for each activation of the pen detection operation synchronization signal EMR_VSYNC synchronized with the touch detection operation synchronization signal TP_VSYNC. In addition, the pen detection operation control circuit 21 is configured such that when the electromagnetic induction pen 2 is detected, the pen detection operation synchronization signal EMR_HSYNC is activated five times at a timing synchronized with the horizontal synchronization signal DISP_HSYNC for each activation of the pen detection operation synchronization signal EMR_VSYNC synchronized with the vertical synchronization signal DISP_VSYNC. Thus, when the electromagnetic induction pen 2 is not detected, the pen detection circuit 23 performs two pen detection operations (specifically, global scanning) each time the touch detection operation synchronization signal TP_VSYNC is activated. On the other hand, when the electromagnetic induction pen 2 is detected by this pen detection operation, the pen detection circuit 23 performs ten pen detection operations (specifically, sector scanning) synchronized with the pen detection operation synchronization signal EMR_HSYNC each time the vertical synchronization signal DISP_VSYNC is activated. It should be noted that the pen detection circuit 23 may also perform one global scan by dispersing it into the above two pen detection operations, or may perform one global scan by dispersing it into the above ten pen detection operations (or five pen detection operations performed according to one activation of the pen detection operation synchronization signal EMR_VSYNC).

[0096] Figure 15 and Figure 16 is a flowchart showing the processing of the pen detection operation control circuit 21 of the present embodiment. In addition, Figure 17 is a flowchart showing Figure 16 the specific content of the EMR-HSYNC activation processing shown. Hereinafter, while referring to these figures, the operation of the sensor controller 30 of the present embodiment will be described in more detail again.

[0097] First, referring to Figure 15 , steps S70 to S72 in the operation of the pen detection operation control circuit 21 of the present embodiment are the same as Figure 11Steps S50 to S52 of the pen detection operation control circuit 21 of the second embodiment shown are the same. In step S72 of the pen detection operation control circuit 21 of this embodiment, after activating the synchronization signal EMR_VSYNC for pen detection operation, the synchronization signal EMR_HSYNC for pen detection operation is activated (step S73). After waiting for a specified time (step S74), the synchronization signal EMR_HSYNC for pen detection operation is activated again (step S75). After that, the pen detection operation control circuit 21 determines whether the electromagnetic induction pen 2 is detected by the pen detection circuit 23 as a result of the activation in steps S73 and S75 (step S76). If it is determined that the pen is not detected, the process returns to step S71. On the other hand, if it is determined that the pen is detected, the process proceeds to Figure 16 step S80.

[0098] Next, referring to Figure 16 , Figure 16 The series of processes shown (steps S80 to S88) are the same as the series of processes (steps S60 to S68) shown in Figure 12 except that the activation of the synchronization signal EMR_VSYNC for pen detection operation (steps S82, S85) performed by receiving the activation of the vertical synchronization signal DISP_VSYNC only occurs twice, and the EMR-HSYNC activation process (steps S83, S86) is performed after activating the synchronization signal EMR_VSYNC for pen detection operation.

[0099] Regarding the EMR-HSYNC activation process performed in steps S83 and S86, if it is described with reference to Figure 17 , the pen detection operation control circuit 21 first sets the variable N, which is a counter, to 0 (step S90), and repeatedly performs the process of determining whether the horizontal synchronization signal DISP_HSYNC has been activated until the horizontal synchronization signal DISP_HSYNC is activated (step S91). In this determination, if it is determined that the horizontal synchronization signal DISP_HSYNC has been activated, the pen detection operation control circuit 21 determines whether the remainder when the variable N is divided by 2 is 1 (step S92). And if it is determined that the remainder is 1, the synchronization signal EMR_HSYNC for pen detection operation is activated (step S93). On the other hand, if it is determined that the remainder is 0, the activation of the synchronization signal EMR_HSYNC for pen detection operation is not performed, and the process proceeds to step S94.

[0100] In step S94, the pen detection operation control circuit 21 increments N by 1 (step S94). Next, it determines whether N is 10 or more (step S95). And, when it is determined that N is not 10 or more, the process returns to step S91 and continues, and when it is determined that N is 10 or more, the EMR - HSYNC activation process ends. Through the processing so far, the pen detection operation control circuit 21 activates the pen detection operation synchronization signal EMR - HSYNC 5 times each time the pen detection operation synchronization signal EMR - VSYNC is activated. In addition, the horizontal synchronization signal DISP_HSYNC is activated when the activation of the horizontal synchronization signal DISP_HSYNC is the even number of times counted from the activation of the previous pen detection operation synchronization signal EMR - VSYNC.

[0101] As described above, also with the sensor controller 30 of the present embodiment, before detecting the electromagnetic induction pen 2, the touch detection operation is executed in synchronization with the pixel driving of the display 42, and the pen detection operation is executed in synchronization with the touch detection operation. On the other hand, when it is received that the electromagnetic induction pen 2 has been detected and the touch detection operation has stopped, although the touch detection operation control circuit 20 does not stop generating the touch detection operation synchronization signal TP_VSYNC, the pen detection operation is executed in synchronization with the pixel driving of the display 42. Therefore, it is possible to reliably suppress the interference between the signal used for the pen detection operation and the signal used for the pixel driving of the display 42.

[0102] As described above, the preferred embodiment of the present invention has been described, but the present invention is in no way limited to such an embodiment, and the present invention can of course be implemented in various ways without departing from its gist.

[0103] Explanation of Reference Numerals

[0104] 1 Position detection system

[0105] 2 Electromagnetic induction pen

[0106] 3 Position detection device

[0107] 3a Panel surface

[0108] 20 Touch detection operation control circuit

[0109] 21 Pen detection operation control circuit

[0110] 22 Touch detection circuit

[0111] 23 Pen detection circuit

[0112] 30 Sensor controller

[0113] 31 Host processor

[0114] 41 Touch sensor

[0115] 42 Display

[0116] 43 EMR sensor

[0117] DISP_VSYNC Vertical synchronization signal

[0118] DISP_HSYNC Horizontal synchronization signal

[0119] EMR_VSYNC, EMR_HSYNC, INT_VS_EMR_G, INT_VS_EMR_S Synchronization signals for pen detection operation

[0120] EMR_TX EMR transmission signal

[0121] EMR_RX EMR reception signal

[0122] EMR_CALC EMR position derivation processing status

[0123] Enable_TP Touch detection enable signal

[0124] F Frame period

[0125] IDLE, PFLG Status flag

[0126] TP_VSYNC Synchronization signal for touch detection operation

[0127] TP_TX Signal for touch detection.

Claims

1. A sensor controller is connected to an EMR sensor disposed overlapping a display, wherein an operation of detecting an electromagnetic induction pen using the EMR sensor is performed synchronously with a touch detection operation for detecting a touch of a passive indicator within a panel surface of the display; when the electromagnetic induction pen is detected, an operation of detecting the electromagnetic induction pen using the EMR sensor is performed synchronously with pixel driving of the display.

2. The sensor controller according to claim 1, wherein the touch detection operation is performed using a touch sensor disposed overlapping the display, and when the electromagnetic induction pen is detected, the touch detection operation is stopped.

3. The sensor controller according to claim 1, wherein an operation of detecting the electromagnetic induction pen performed synchronously with the touch detection operation is performed with lower power than an operation of detecting the electromagnetic induction pen performed synchronously with pixel driving of the display.

4. The sensor controller according to claim 3, wherein an operation of detecting the electromagnetic induction pen performed synchronously with the touch detection operation and an operation of detecting the electromagnetic induction pen performed synchronously with pixel driving of the display are operations of detecting the electromagnetic induction pen over the entire panel surface.

5. The sensor controller according to claim 4, wherein an operation of detecting the electromagnetic induction pen performed synchronously with the touch detection operation is an operation of detecting the electromagnetic induction pen over a longer time than an operation of detecting the electromagnetic induction pen performed synchronously with pixel driving of the display.

6. The sensor controller according to claim 4 or 5, wherein after the electromagnetic induction pen is detected by an operation of detecting the electromagnetic induction pen performed synchronously with pixel driving of the display, an operation of detecting the electromagnetic induction pen for updating a position of the detected electromagnetic induction pen is performed synchronously with pixel driving of the display.

7. The sensor controller according to claim 1 or 2, wherein an operation of detecting the electromagnetic induction pen performed synchronously with pixel driving of the display is an operation of detecting the electromagnetic induction pen for updating a position of the detected electromagnetic induction pen.

8. The sensor controller according to claim 7, wherein an operation of detecting the electromagnetic induction pen performed synchronously with pixel driving of the display is performed synchronously with a horizontal synchronization signal of the display.

9. The sensor controller according to claim 7, wherein when the electromagnetic induction pen is not detected as a result of performing an operation of detecting the electromagnetic induction pen performed synchronously with pixel driving of the display, an operation of detecting the electromagnetic induction pen performed synchronously with the touch detection operation is performed.

10. A method, performed by a sensor controller coupled to an EMR sensor disposed overlapping a display, wherein, comprising: a step of performing an operation of detecting an electromagnetic induction pen using the EMR sensor synchronously with a touch detection operation for detecting a touch of a passive indicator within a panel surface of the display; and When the electromagnetic induction pen is detected, steps for using the EMR sensor to detect the operation of the electromagnetic induction pen are performed synchronously with the pixel driving of the display.

11. A position detection device, comprising: A display; An EMR sensor and a touch sensor, configured to overlap with the display; and A sensor controller, respectively connected to the EMR sensor and the touch sensor, Among them, The sensor controller performs an operation for using the EMR sensor to detect an electromagnetic induction pen synchronously with a touch detection operation using the touch sensor for detecting a touch of a passive indicator within the panel surface of the display, When the electromagnetic induction pen is detected, the sensor controller performs an operation for using the EMR sensor to detect the electromagnetic induction pen synchronously with the pixel driving of the display.

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