JP2021193625A - Pointer position detection method - Google Patents

Abstract

To prevent an unnecessary line segment from being drawn by the existence of a ghost position.SOLUTION: A pointer position detection method includes a pen detection step for detecting a pen signal transmitted through a pen electrode, and detecting a pen position being the position of an active pen on the basis of the level of the detected pen signal. The pen detection step outputs a pen position detected this time (step S4) after outputting pen-up information showing that the active pen is separated from a touch surface (step S105) in the case that a distance between the pen position detected this time and a pen position detected at the preceding time exceeds a prescribed value (affirmative determination of step S104), and outputs the pen position detected this time (step S4) without outputting the pen-up information in the case that the distance between the pen position detected this time and the pen position detected at the preceding time does not exceed the prescribed value (negative determination of step S104).SELECTED DRAWING: Figure 24

Description

The present invention relates to a pointer position detection method, and more particularly to a pointer position detection method for performing detection of an active electrostatic type electronic pen and detection of a passive pointer such as a finger in parallel.

Conventionally, as an electronic pen, an electromagnetic resonance type (hereinafter referred to as "EMR pen") is known. The EMR pen is an electronic pen configured to transmit an alternating magnetic field from the pen tip. The tip of the EMR pen is made of a non-conductor such as resin so as not to disturb the alternating magnetic field.

Further, in recent years, the development of an active electrostatic type (hereinafter referred to as "active pen") has been progressing. An active pen is an electronic pen configured to transmit a signal from a pen tip by an electric field. The tip of an active pen is configured to include a conductor (pen electrode) such as metal that acts as an antenna to generate an electric field.

Further, in recent years, an example of using an auxiliary device (hereinafter, collectively referred to as a “passive pointer”) that does not transmit a signal like a finger or a finger in combination with an electronic pen is increasing. For example, while drawing a picture with an electronic pen in the right hand, auxiliary work such as zooming in, zooming out, and rotating is performed with the finger of the left hand or an auxiliary device. In such a case, the position detector that detects the pointer needs to detect the electronic pen and the passive pointer in parallel.

Patent Document 1 discloses an example of a position detector that performs detection of an EMR pen and detection of a passive pointer in parallel. As shown in FIG. 4 of the same document, in the position detector that performs the detection of the EMR pen and the detection of the passive pointer in parallel, it is necessary to separately prepare a sensor used for each detection. The detection sensor of the EMR pen is provided with a function of generating an alternating magnetic field and a function of receiving a signal transmitted by the EMR pen. On the other hand, the passive pointer detection sensor is provided with a function of detecting a capacitive coupling that occurs between the tip of the passive pointer (for example, a fingertip) and an electrode arranged in the sensor. Since the passive pointer does not transmit a signal in response to the alternating magnetic field and the EMR pen does not capacitively couple with the electrodes in the sensor, the detection of the EMR pen and the detection of the passive pointer are performed at exactly the same timing (according to time division). Can be done (without).

Further, Patent Document 2 discloses an example of a position detector that performs detection of an active pen and detection of a passive pointer in parallel. As shown in FIG. 6 of the same document, the detection of the active pen and the detection of the passive pointer are performed using the same sensor. With respect to the passive pointer, this sensor detects the capacitive coupling between the tip of the passive pointer and the electrode arranged in the sensor, similarly to the sensor for detecting the passive pointer described above with respect to Patent Document 1. Perform detection. On the other hand, with respect to the active pen, the detection is executed by transmitting a signal to the active pen and receiving the signal transmitted by the active pen accordingly. At this time, the conductor (pen electrode) arranged at the tip of the active pen and the electrode arranged in the sensor each function as an antenna for transmitting and receiving signals. Since the detection of the passive pointer and the detection of the active pen are performed by the same sensor, the detection of the active pen and the detection of the passive pointer cannot be executed at exactly the same timing, and both are executed in a time division manner. ..

Japanese Patent No. 4787087 Japanese Patent No. 6082172

By the way, the conventional position detector that detects the active pen and the passive pointer in parallel has a problem that the contact position of the active pen and the contact position of the passive pointer are erroneously recognized. , Improvement was required. Hereinafter, it will be described in detail.

First, the position detector erroneously recognizes the contact position of the active pen as the contact position of the passive pointer because the pen electrode of the active pen causes a capacitive coupling with the electrode in the sensor. Since the position detector cannot distinguish this capacitive coupling from the capacitive coupling generated by the contact of the passive pointer, it mistakenly recognizes that the passive pointer is in contact. In recent years, many position detectors are configured to be able to recognize multiple passive pointers, but with such a position detector, the contact of the active pen can be made with the second and third passive pointers. It will be mistakenly recognized as a contact.

Next, the position detector mistakenly recognizes the contact position of the passive pointer as the contact position of the active pen because the transmission signal of the active pen is transmitted to the palm etc. through the human body and transmitted from there to the sensor. This is because it ends up. Since the position detector cannot distinguish the signal received in this way from the signal directly transmitted from the pen electrode of the active pen, the contact position of the palm is erroneously recognized as the contact position of the active pen.

Therefore, one of the objects of the present invention is to provide a pointer position detection method capable of correctly discriminating between the contact position of the active pen and the contact position of the passive pointer.

Further, as described above, the detection of the active pen and the detection of the passive pointer are executed in a time division manner. Assuming that the time required for detecting the active pen is 3 milliseconds each time and the time required for detecting the passive pointer is 2 milliseconds each time, active pen detection and passive pointer detection are alternately executed. The detection rate of the pen and the detection rate of the passive pointer are equal (both about 200 (1/5 x 1000) times / sec).

In such a case, in order to further improve the detection rate of the active pen, for example, it is conceivable to perform the active pen detection twice in succession and then perform the passive pointer detection once.

However, if the control method is adopted in which the detection of the active pen and the detection of the passive pen are simply executed at an appropriate ratio as described above, the interval between the active pen detections may not be constant. For example, in the case of the above example, after the active pen detection is executed twice in succession, the next active pen detection is delayed until the passive pointer detection is completed. Then, in a drawing application that operates with the expectation that the coordinate data of the active pen sequentially output from the sensor controller is transmitted at equal intervals in time, there arises a problem that the drawing result becomes unnatural. Therefore, improvement was required.

Therefore, another object of the present invention is to provide a pointer position detection method capable of executing active pen detection at equal intervals while maintaining the detection rates of both the active pen and the passive pointer.

Further, when the position detector detects the active pen, the position where neither the active pen nor the passive pointer is in contact may be erroneously recognized as the contact position of the active pen. This results in a current path from the pen electrode of the active pen through the electrode in the sensor to the arm opposite the hand holding the active pen and back to the active pen via the human body. This is because the transmission signal of the active pen may be detected below this arm. Hereinafter, the contact position of the active pen that is erroneously recognized in this way is referred to as a “ghost position”.

For example, if the active pen suddenly moves into the touch plane from the bezel area of the tablet that makes up the position detector, the position detector may detect the ghost position before detecting the actual pen position. be. Then, an unnecessary line segment is drawn between the detected ghost position and the actual pen position detected immediately after that, so improvement is required.

Therefore, still another object of the present invention is to provide a pointer position detection method capable of preventing an unnecessary line segment from being drawn due to the presence of a ghost position.

The pointer position detection method according to the present invention is executed by a sensor controller connected to a sensor pattern, and is configured to be able to transmit a signal from the position of a passive pointer that does not transmit a signal and a pen electrode provided at the tip portion. It is a method of detecting the position of the pen and the position of the pointer for detecting the position of the active pen by detecting the pen signal transmitted through the pen electrode and based on the detected level of the pen signal. By detecting the pen detection step for detecting the pen position and the change in capacitance in the sensor pattern, one or more candidate touch positions that are candidates for the position of the passive pointer are detected, and the one or more candidate touch positions are detected. It is a pointer position detection method including a touch detection step of outputting one or more candidate touch positions excluding the pen position from the inside as a passive pointer position which is the position of the passive pointer.

Further, the pointer position detection method according to another aspect of the present invention is a pointer position detection method existing in a predetermined area, and executes 1 / N of the first detection process at the first detection rate. Then, the first detection step of acquiring the partial detection data indicating whether or not the first pointer exists based on the 1 / N processing and holding it in the memory, and the first detection step are the portions. Each time the detection data is newly held in the memory, the partial detection data for N-1 pieces held in the memory up to that point and the newly held partial detection data are combined to obtain the predetermined value. A pointer that includes a synthesis step that generates global detection data indicating whether or not the first pointer exists for the entire region of the region, and a report step that outputs the global detection data at the first detection rate. It is a position detection method of.

Further, the pointer position detection method according to still another aspect of the present invention is a pointer position detection method existing in a predetermined region, in which the entire second detection process is executed at the second detection rate, and the second detection process is performed. A second detection step for executing the detection of the 2 pointers, a 1 / N process of the first detection process at the first detection rate, and the second pointer based on the 1 / N process. Includes a first detection step that acquires partial detection data indicating whether or not a different first pointer exists and holds it in memory, the second detection step, and the first detection step. Is a pointer position detection method that is executed alternately.

Further, the pointer position detection method according to still another aspect of the present invention is a pointer position detection method existing in a predetermined region including K first electrodes and K second electrodes. N × M pulse groups each consisting of K pulses are sequentially read out from the memory one pulse group at a time, and each time the reading is performed, the K pulses constituting the read pulse group are transferred to the K first electrode. A detection step of transmitting to each of them and storing partial detection data indicating the level of the signal output from each of the K second electrodes as a result of the transmission in the memory, and M by the detection step. Each time the partial detection data corresponding to each of the pulse groups of the above is stored in the memory, (N-1) × M pulse groups previously stored in the memory for each of the second electrodes. A method for detecting the position of a pointer, which comprises a synthesis step of synthesizing with the partial detection data corresponding to each of the above and generating synthetic detection data indicating whether or not the pointer is present on the corresponding second electrode. Is.

Further, the method of detecting the position of the pointer by still another aspect of the present invention is executed by the sensor controller connected to the sensor pattern, and the position of the passive pointer that does not transmit the signal and the signal from the pen electrode provided at the tip portion are transmitted. It is a pointer position detection method for detecting the position of the active pen configured to be transmittable, and detects the position of the passive pointer and determines the palm area by detecting the change in capacitance in the sensor pattern. The touch detection step includes a pen detection step of detecting a pen signal transmitted through the pen electrode and detecting a pen position which is the position of the active pen based on the detected level of the pen signal. In the pen detection step, (1) the previously detected pen position is within a predetermined area with respect to the palm area, and (2) the pen position detected this time and the previously obtained pen are obtained. This is a pointer position detection method that outputs pen-up information indicating that the active pen has moved away from the touch surface when the distance from the position exceeds a predetermined value.

Further, the method of detecting the position of the pointer by still another aspect of the present invention is executed by the sensor controller connected to the sensor pattern, and the position of the passive pointer that does not transmit the signal and the signal from the pen electrode provided at the tip portion are transmitted. It is a pointer position detection method for detecting the position of the active pen configured to be transmittable, and detects the position of the passive pointer and determines the palm area by detecting the change in capacitance in the sensor pattern. The touch detection step and the pen signal transmitted through the pen electrode are detected, the pen position which is the position of the active pen is detected based on the detected level of the pen signal, and the active pen transmits. The pen detection step includes a pen detection step that detects pen pressure based on the pen signal, and the pen detection step determines whether or not the pen position detected this time exists in the vicinity of the palm region, and determines that the pen position exists. In this case, if the previously detected pen pressure is invalid, the pen position detected this time is invalidated, and if the previously detected pen pressure is valid, the pen position detected this time is valid. It is a method of detecting the position of the pointer.

According to the pointer position detection method according to the present invention, one or more candidate touch positions to be output as the passive pointer position can be selected according to the active pen position held in the memory, so that the contact position of the active pen and the passive pointer can be selected. It becomes possible to correctly identify the contact position of the.

According to the pointer position detection method according to the present invention, the first detection process (passive pointer position detection process) is executed in N times, so that the active pen and the passive pointer are active while maintaining the detection rates of both. Pen detection can be performed at regular intervals.

According to the pointer position detection method according to the present invention, pen-up information can be output when the distance between the pen position detected this time and the pen position detected last time exceeds a predetermined value, so that the ghost can be output. It is possible to prevent unnecessary line segments from being drawn due to the existence of positions.

It is a figure which shows an example of the use state of the position detection system 1 by 1st Embodiment of this invention. It is a flow diagram which shows the outline of the position detection process of a pointer executed by the sensor controller provided in the position detector by the background technique of this invention. It is a flow diagram which shows the outline of the position detection process of a pointer executed by the sensor controller 31 by embodiment of this invention. It is a figure which shows the structure of the tablet 3 shown in FIG. It is a figure which shows the principle of the position detection process of the finger 4 executed by the MCU 40 shown in FIG. 4. (A) is a diagram showing a pen position table used in the output position determination process according to the embodiment of the present invention, and (b) is a touch used in the output position determination process according to the embodiment of the present invention. It is a figure which shows the position table. It is a figure which shows an example of the output position determination process performed by the MCU 40 using the pen position table and the touch position table shown in FIG. It is a figure which shows an example of the output position determination process performed by the MCU 40 using the pen position table and the touch position table shown in FIG. It is a figure which shows the detail of the flow chart shown in FIG. It is a figure which shows the detail of the flow chart shown in FIG. It is a flow diagram which shows the position detection process of the pointer executed by the sensor controller 31 by the 4th modification of embodiment of this invention. (A) is a diagram showing a control sequence related to pointer position detection processing according to the background technique of the present invention, and (b) is a diagram showing a control sequence related to pointer position detection processing according to the embodiment of the present invention. Is. It is a figure which shows an example of the finger detection signal FDS used together with a 16 × 16 sensor 30. It is a figure which shows the 1st example of the content of 1 / N processing by embodiment of this invention. It is a figure which shows the 2nd example of the content of 1 / N processing by embodiment of this invention. It is a figure which shows the 3rd example of the content of 1 / N processing by embodiment of this invention. It is a figure which shows the 4th example of the content of 1 / N processing by embodiment of this invention. It is a figure which shows the 5th example of the content of 1 / N processing by embodiment of this invention. It is a figure which shows an example of the specific storage contents of the shift register 40a in the 5th example. It is a figure which shows another example of the specific storage contents of the shift register 40a in the 5th example. (A) is a diagram showing a control sequence related to pointer position detection processing according to the first modification of the embodiment of the present invention, and (b) is a second modification of the embodiment of the present invention. It is a figure which shows the control sequence which concerns on the position detection process of the pointer by It is a figure which shows an example of the use state of the position detection system 1 by the 2nd Embodiment of this invention. It is a figure explaining the operation of the host processor 32 by the background technique of the 2nd Embodiment of this invention. It is a flow diagram which shows the position detection process of the pointer executed by the sensor controller 31 by the 2nd Embodiment of this invention.

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

FIG. 1 is a diagram showing an example of a usage state of the position detection system 1 according to the first embodiment of the present invention. As shown in the figure, the position detection system 1 according to the present embodiment includes an active pen 2 and a tablet 3. The tablet 3 has a touch surface 3a, and is configured to be able to detect the positions of the active pen and the passive pointer on the touch surface 3a. FIG. 1 shows how the tip of the active pen 2, the tip of the finger 4 as a passive pointer, and the hand 5 of the user holding the active pen 2 are in contact with the touch surface 3a. The user's finger 4 is shown as an example of the passive pointer, and the type of the passive pointer does not matter in the present embodiment. In the following description, the active pen 2 and the passive pointer represented by the finger 4 may be collectively referred to as a “pointer”.

Here, before explaining the contents of the present embodiment in detail, the outline of the present invention will be described with reference to FIGS. 2 and 3.

First, FIG. 2 is a flow chart showing an outline of a pointer position detection process executed by a sensor controller (not shown) provided in a tablet according to the background technology of the present invention. As shown in the figure, the sensor controller according to the background technique of the present invention is configured to repeatedly execute the processes of steps S101 to S106 (step S100).

Specifically, the processes of steps S101 to S106 will be specifically described. First, the sensor controller executes the position detection process of the active pen 2 (step S101), and outputs the detected position to the host processor (not shown) (step). S102). Subsequently, the position detection process of the active pen 2 is executed again (step S103), and the detected position is output to the host processor (step S104). Next, the sensor controller executes the position detection process of the finger 4 (step S105), and outputs the detected position to the host processor (step S106).

The reason why the position detection process of the active pen 2 is performed twice in succession in steps S101 and S103 is to secure the detection rate of the active pen 2 as described above. However, since the detection interval of the active pen 2 becomes not constant by doing so, as described above, for example, the coordinate data of the active pen 2 sequentially output from the sensor controller is transmitted at equal intervals in time. In a drawing application that operates with the expectation of this, there is a problem that the drawing result becomes unnatural.

Further, as described above, the position detection process of the active pen 2 has a problem that the contact position of the hand 5 may be erroneously detected as the position of the active pen, and the position detection process of the finger 4 has a problem. There is a problem that the contact position of the active pen 2 or the hand 5 may be detected as the position of the finger 4.

The processing performed by the sensor controller 31 (see FIG. 4 described later) provided on the tablet 3 according to the present embodiment can solve these problems. Hereinafter, an outline thereof will be described with reference to FIG.

FIG. 3 is a flow chart showing an outline of the pointer position detection process executed by the sensor controller 31. As shown in the figure, the sensor controller 31 is configured to repeatedly execute the processes of steps S2 to S9 (step S1). Of these, steps S2 to S4 are pen detection steps for detecting the pen position which is the position of the active pen 2, and steps S5 to S9 are touch detection for detecting the passive pointer position which is the position of the finger 4. It is a step.

The processing of steps S2 to S9 will be specifically described in comparison with the processing shown in FIG. 2. First, the position detection processing itself of step S2 is the same as the position detection processing of step S101. However, the output process of the detected position is different from step S102 of the background technique. That is, the sensor controller 31 does not output the position detected in step S2 as it is to the host processor 32 (see FIG. 4 described later), but selects the pen position from the detected one or more positions (candidate pen positions). It is configured to perform a determination process (hereinafter referred to as "pen position determination process") (step S3) and output only the determined pen position to the host processor 32 (step S4). The specific content of the pen position determination process will be described later, but since the contact position of the hand 5 can be excluded from the output target in this process, the sensor controller 31 correctly identifies the contact position of the active pen 2. can.

Next, the sensor controller 31 performs the position detection process of the finger 4 in step S5, but in one process, it executes only 1 / N of the position detection process executed in step S105 (step S5). .. The specific content of the 1 / N process will be described later, but since only 1 / N is executed, the sensor controller 31 needs to synthesize the results for N times in order to obtain the position of the finger 4. Therefore, the sensor controller 31 records data (hereinafter, referred to as "partial detection data") indicating the partial detection result obtained by the 1 / N process (step S6), and records N- in the past. It is configured to generate data indicating the position of the finger 4 (hereinafter referred to as “total detection data”) by combining with the partial detection data for one time (step S7). Since the 1 / N process is completed in about 1 / N time as compared with the position detection process executed in step S105, the process of the sensor controller 31 is configured as in steps S5 to S7, and FIG. It is possible to secure the detection rate of the active pen 2 without executing the position detection process of the active pen 2 twice in succession as in the example of.

After that, the sensor controller 31 determines the passive pointer position from one or more positions (candidate touch positions) indicated by the overall detection data generated in step S7 (hereinafter, referred to as "passive pointer position determination process"). (Step S8), and output only the determined passive pointer position to the host processor 32 (step S9). The purpose of executing the processes of steps S8 and S9 is the same as that of steps S3 and S4, and the contact positions of the active pen 2 and the hand 5 can be excluded from the output target in this process, so that the sensor controller 31 can be used. , The contact position of the finger 4 can be correctly identified. The specific content of the passive pointer position determination process will also be described later. Hereinafter, the pen position determination process and the passive pointer position determination process may be collectively referred to as “output position determination process”.

The outline of the present invention has been described above. Hereinafter, the contents of the present embodiment will be described in detail with reference to FIG. Hereinafter, the overall outline of the configuration of the position detection system 1 according to the present embodiment will be described first, and then the detailed contents of the output position determination process and the 1 / N process described above will be described in order.

The active pen 2 is an electronic pen that operates by an active electrostatic method. Although not shown, a control unit and a transmission / reception unit are provided inside the active pen 2, and the control unit is configured to be able to transmit and receive signals to and from the tablet 3 via the transmission / reception unit. Hereinafter, the signal transmitted from the tablet 3 toward the active pen 2 is referred to as an uplink signal US, and the signal transmitted from the active pen 2 toward the tablet 3 (pen signal) is referred to as a downlink signal DS.

A pen electrode is provided at the tip of the active pen 2, and the transmitting / receiving portion of the active pen 2 includes the pen electrode and a sensor 30 provided on the touch surface 3a of the tablet 3 (see FIG. 4 described later). The uplink signal US is received and the downlink signal DS is transmitted via the capacitance formed between them. The pen electrode for receiving the uplink signal US and the pen electrode for transmitting the downlink signal DS may be different or the same.

The active pen 2 also has a pen pressure detection unit that detects the pressure (pen pressure) applied to the pen tip, a side switch state detection unit that detects the on / off state of the side switch provided on the side surface, and a pre-assigned unique ID. It is configured to have a storage unit (memory) for storing the active pen 2 and a power supply unit (battery) for supplying the operating power of the active pen 2. The control unit of the active pen 2 is configured to be able to control each of these units.

The downlink signal DS includes a position signal which is a burst signal having a predetermined frequency, and a data signal including data transmitted from the active pen 2 to the tablet 3. The position signal is used in the tablet 3 to detect the position of the active pen 2. The data transmitted by the data signal is, for example, data indicating the pen pressure detected by the pen pressure detection unit (pen pressure data) and data indicating the on / off state of the side switch acquired by the side switch state detection unit (switch data). , A unique ID stored in the storage unit, etc., which is arranged in the data signal by the control unit.

The uplink signal US includes a predetermined start bit and a command indicating a command from the tablet 3 to the active pen 2. The control unit of the active pen 2 is configured to take out a command from the received uplink signal US, decode it, and arrange data according to the content in the data signal. This allows the tablet 3 to retrieve the desired data from the active pen 2.

The tablet 3 is an electronic device having both a function as a liquid crystal display device and a function as a position detector for detecting the position of a pointer on the touch surface 3a. The touch surface 3a is provided on the liquid crystal display screen. Further, the pointers that can be detected by the tablet 3 include both the active pen 2 and the finger 4 shown in FIG.

Although details will be described later with reference to FIG. 4, a sensor 30 including a plurality of sensor electrodes 30X and 30Y (sensor patterns) is provided inside the touch surface 3a. The tablet 3 detects the position of the finger 4 (passive pointer position) by detecting the change in the capacitance in the sensor 30, and detects the position signal described above by the sensor 30 to detect the position of the active pen 2 (pen position). ) Is configured to be detected.

Each sensor electrode 30X also serves as a common electrode of the liquid crystal display device, and during the pixel drive operation, a pixel drive voltage Vcom, which is a fixed potential, is supplied to each sensor electrode 30X. The type of tablet 3 in which the sensor electrode for position detection is also used as the electrode for the liquid crystal display is generally called "in-cell type". In the "in-cell type" tablet 3, the sensor electrode 30X cannot be used for position detection during the pixel drive operation, so that the position detection of the finger 4 or the active pen 2 is performed by the pixel drive operation interval (for example, the horizontal return period). And the vertical return period). However, the present invention is similarly applicable to a tablet (non-incell type) in which a plurality of sensor electrodes 30X and 30Y are independent of the electrodes (common electrode and pixel electrode) of the liquid crystal display device. ..

FIG. 4 is a diagram showing the configuration of the tablet 3. As shown in the figure, the tablet 3 includes a sensor 30, a sensor controller 31, and a host processor 32.

The sensors 30 extend in the Y direction and are arranged at equal intervals in the X direction orthogonal to the Y direction, and the sensors 30 extend in the X direction and are arranged at equal intervals in the Y direction. It has a configuration in which a plurality of sensor electrodes 30Y are arranged in a matrix. Although the example in which the sensor electrodes 30X and 30Y are both formed of a linear conductor is shown here, it is also possible to form the sensor electrodes 30X and 30Y with a conductor having another shape. For example, one of the sensor electrodes 30X and 30Y may be configured by a plurality of rectangular conductors arranged in two dimensions so that the two-dimensional coordinates of the active pen 2 can be detected.

The sensor controller 31 is configured to use this sensor 30 to perform communication with the active pen 2 (including position detection of the active pen 2) and position detection of the finger 4 at intervals of pixel drive operations in a time-divided manner. To. Further, during the pixel drive operation, the pixel drive voltage Vcom is configured to be supplied to each of the plurality of sensor electrodes 30X. Hereinafter, the configuration of the sensor controller 31 will be described in more detail.

As shown in FIG. 4, the sensor controller 31 includes an MCU 40, a logic unit 41, transmission units 42 and 43, a reception unit 44, and a selection unit 45.

The MCU 40 and the logic unit 41 are control units that control the transmission / reception operation of the sensor controller 31 by controlling the transmission units 42, 43, the reception unit 44, and the selection unit 45. Specifically, first, the MCU 60 is a microprocessor that has a memory (ROM and RAM) inside and operates by executing a program stored in the memory. The operation timing of the MCU 40 is controlled by a timing signal supplied from the host processor 32. In addition to the control operation of the logic unit 41, the operation performed by the MCU 40 includes an operation of supplying the pixel drive voltage Vcom to the selection unit 45, an operation of controlling the transmission unit 42 to output the finger detection signal FDS, and an active operation. The positions of the active pen 2 and the finger 4 (specifically, the touch surface 3a) based on the operation of supplying the command COM indicating the content of the instruction to the pen 2 to the transmitting unit 43 and the digital signal supplied from the receiving unit 44. The data Res (for example, the pressure data and the switch data described above) transmitted by the active pen 2 by the operation of detecting the coordinates x, y) indicating the position in the active pen 2 and the decoding of the digital signal supplied from the receiving unit 44. , Or a unique ID), and an operation of determining the contact state of the active pen 2 with respect to the touch surface 3a based on the pen pressure data included in the data Res. The logic unit 41 has a function of outputting control signals ctrl_t1 to ctrl_t4 and ctrl_r based on the control of the MCU 40.

The transmission unit 42 is a circuit that generates a finger detection signal FDS according to the control of the MCU 40 and supplies it to each sensor electrode 30X through the selection unit 45. Here, the specific contents of the finger detection signal FDS and the method of supplying the finger detection signal FDS to each sensor electrode 30X will be described with reference to FIG.

FIG. 5 is a diagram showing the principle of the position detection process of the finger 4 executed by the MCU 40. The figure shows a state before the position detection process of the finger 4 is divided into the 1 / N processes shown in FIG. 3, that is, the position detection process of the finger 4 executed in step S105 shown in FIG. There is. For simplicity, the figure shows only four sensor electrodes 30X, but in reality more sensor electrodes 30X are arranged. Hereinafter, the description will be continued assuming that the number of the sensor electrodes 30X is K.

5, the signal detection finger FDS, for example, composed of the K signals s ₁ ~s _K consisting of pulses each represented by "1" or "-1" the K. Pulse of the signal _s 1 ~s _K each n-th (n = 1 to K) constitute a pulse group _{p n,} each pulse constituting one pulse group _{p n} from the transmission unit 42 shown in FIG. 4 It is input to each sensor electrode 30X in parallel through the selection unit 45.

Return to FIG. The transmission unit 43 is a circuit that generates an uplink signal US according to the control of the MCU 40 and the logic unit 41 and supplies it to the selection unit 45. As shown in the figure, the pattern supply unit 50, the switch 51, and the code string holding unit 52, a diffusion processing unit 53, and a transmission guard unit 54 are included. Of these, the pattern supply unit 50 will be described as being included in the transmission unit 43 in the present embodiment, but may be included in the MCU 40.

The pattern supply unit 50 holds the start bit SB arranged at the head of the uplink signal US, and outputs the held start bit SB according to the instruction of the control signal ctrl_t1 supplied from the logic unit 41. It is composed.

The switch 51 has a function of selecting one of the pattern supply unit 50 and the MCU 40 based on the control signal ctrl_t2 supplied from the logic unit 41, and supplying the selected output to the diffusion processing unit 53. When the switch 51 selects the pattern supply unit 50, the start bit SB is supplied to the diffusion processing unit 53. On the other hand, when the switch 51 selects the MCU 40, the command COM is supplied to the diffusion processing unit 53.

The code sequence holding unit 52 has a function of generating and holding a diffusion code having a predetermined chip length having an autocorrelation characteristic based on the control signal ctrl_t3 supplied from the logic unit 41. The diffusion code held by the code string holding unit 52 is supplied to the diffusion processing unit 53.

The spreading processing unit 53 modulates the spreading code held by the code string holding unit 52 based on the value (start bit SB or command COM) supplied via the switch 51, thereby transmitting a transmission chip sequence having a predetermined chip length. Has the function of acquiring. The diffusion processing unit 53 supplies the acquired transmission chip sequence to the selection unit 45 via the transmission guard unit 54.

The transmission guard unit 54 is required to switch between a transmission operation and a reception operation between the transmission period of the uplink signal US and the reception period of the downlink signal DS based on the control signal ctrl_t4 supplied from the logic unit 41. It has a function to insert a guard period (a period during which both transmission and reception are not performed).

The selection unit 45 includes switches 58x, 58y and conductor selection circuits 59x, 59y.

The switch 58y is a switch element configured so that the common terminal and any one of the T terminal and the R terminal are connected. The common terminal of the switch 58y is connected to the conductor selection circuit 59y, the T terminal is connected to the output terminal of the transmitting unit 43, and the R terminal is connected to the input terminal of the receiving unit 44. Further, the switch 58x is a switch element configured so that the common terminal and any one of the T1 terminal, the T2 terminal, the D terminal, and the R terminal are connected. Of these, the T2 terminal is actually a set of terminals for the number of sensor electrodes 30X. The common terminal of the switch 58x is connected to the conductor selection circuit 59x, the T1 terminal is connected to the output end of the transmission unit 43, the T2 terminal is connected to the output end of the transmission unit 42, and the D terminal outputs the pixel drive voltage Vcom. It is connected to the output end of the MCU 40, and the R terminal is connected to the input end of the receiving unit 44.

The conductor selection circuit 59x is a switch element for selectively connecting a plurality of sensor electrodes 30X to the common terminal of the switch 58x. The conductor selection circuit 59x is configured so that a part or all of the plurality of sensor electrodes 30X can be connected to the common terminal of the switch 58x at the same time. When the T2 terminal and the common terminal are connected in the switch 58x, the conductor selection circuit 59x connects a plurality of terminals constituting the T2 terminal and a plurality of sensor electrodes 30X on a one-to-one basis.

The conductor selection circuit 59y is a switch element for selectively connecting a plurality of sensor electrodes 30Y to the common terminal of the switch 58y. The conductor selection circuit 59y is also configured so that a part or all of the plurality of sensor electrodes 30Y can be connected to the common terminal of the switch 58y at the same time.

Four control signals sTRx, sTRy, selX, and selY are supplied to the selection unit 45 from the logic unit 41. Specifically, the control signal sTRx is supplied to the switch 58x, the control signal sTRy is supplied to the switch 58y, the control signal selX is supplied to the conductor selection circuit 59x, and the control signal selY is supplied to the conductor selection circuit 59y. By controlling the selection unit 45 using these control signals sTRx, sTRy, selX, and selY, the logic unit 41 transmits the uplink signal US or the finger detection signal FDS, and applies and downs the pixel drive voltage Vcom. It realizes reception of link signal DS or finger detection signal FDS.

More specifically, first, at the timing of transmitting the uplink signal US, the logic unit 41 controls the selection unit 45 so that all of the plurality of sensor electrodes 30Y are connected to the transmission unit 43 at the same time. .. As a result, the uplink signal US is transmitted from all of the plurality of sensor electrodes 30Y at the same time, so that the active pen 2 can receive the uplink signal US from anywhere on the touch surface 3a.

Next, at the timing of receiving the above-mentioned position signal in the downlink signal DS, the logic unit 41 selects a plurality of sensor electrodes 30X and 30Y one by one in order, and the selected sensor electrodes 30X and 30Y are sent to the receiving unit 44. The selection unit 45 is controlled so as to be connected. As a result, a number of position signals equal to the number of sensor electrodes 30X and 30Y are sequentially supplied to the receiving unit 44. As will be described in detail later, the MCU 40 is configured to detect the position of the active pen 2 based on the level of the position signal thus supplied to the receiving unit 44.

Specifically, the MCU 40 determines the level of the position signal at each intersection of the plurality of sensor electrodes 30X and 30Y based on the digital signal (described later) supplied from the receiving unit 44. Then, the position of the active pen 2 is detected based on each determined level. Specifically, a region in the touch surface 3a where the level of the position signal is equal to or higher than a predetermined value may be determined, and for example, the center position thereof may be detected as the position of the active pen 2.

At the timing of receiving the above-mentioned data signal among the downlink signal DS, first, one or more of the plurality of sensor electrodes 30X and 30Y are selected by the MCU 40. This selection is performed based on the position of the active pen 2 detected based on the previous position signal. Then, the logic unit 41 controls the selection unit 45 so that the selected sensor electrodes 30X and 30Y are connected to the reception unit 44. This makes it possible to supply the data signal transmitted by the active pen 2 to the receiving unit 44.

In the next timing of transmitting the finger detecting signal FDS, the logic unit 41, together with the MCU 40, and selects one of the sensor electrodes 30Y, the pulse group _p 1 ~p _K described above sequentially to each sensor electrodes 30X to the transmitter 42 The operation of inputting is repeated for each sensor electrode 30Y. Specifically, the logic unit 41 first controls the selection unit 45 so that the plurality of terminals constituting the T2 terminal of the switch 58x and the plurality of sensor electrodes 30X are connected one-to-one. Then, while maintaining that state, a plurality of sensor electrodes 30Y are sequentially selected one by one, and the selection unit 45 is controlled so that the selected sensor electrodes 30Y are connected to the receiving unit 44.

MCU40 Furthermore, while selecting one of the sensor electrodes 30Y, sequentially reads the pulse group p ₁ ~p _K by one pulse group from the memory, each of the read, read the K constituting the pulse group The pulse is supplied to the transmission unit 42. The transmission unit 42 inputs the K pulses thus supplied to the K sensor electrodes 30X in parallel. The level of the digital signal supplied from the receiving unit 44 as a result of such control reflects the change in the capacitance formed at the intersection of the selected sensor electrode 30Y and each sensor electrode 30X. Therefore, the MCU 40 is configured to detect the position of the finger 4 based on the level of the digital signal supplied from the receiving unit 44.

Here, the position detection process of the finger 4 executed by the MCU 40 will be described in more detail with reference to FIG. 5 again. Hereinafter, the description will be made assuming that the number of the sensor electrodes 30X is 4 (that is, K = 4), but the same applies to the case where the number of the sensor electrodes 30X is 3 or less or 5 or more.

When the number of sensor electrodes 30X is 4, the signals s _{1 to s K} are composed of four pulses represented by "1" or "-1", respectively. Specifically, as shown in FIG. 5, the signal s ₁ is “1,1,1,1”, the signal s ₂ is “1,1, -1, -1”, and the signal s ₃ is “1, −”. 1, -1, 1 "and the signal s ₄ are composed of" 1-1, 1, -1 ", respectively.

The MCU 40 is functionally configured to include a shift register 40a and a correlator 40b. The shift register 40a is a FIFO format storage unit, and is configured to be able to store the same number (that is, K) of data as the number of sensor electrodes 30X. When new data is stored in the shift register 40a, the data stored K times before is erased. MCU40 and logic unit 41, as described above, selects one of the sensor electrodes 30Y, to input the pulse group _p 1 ~p ₄ sequentially to each sensor electrodes 30X to the transmitting unit 42, for each sensor electrode 30Y operations that repeat. Thus, the sensor electrode 30Y in selection, four levels _L 1 ~L ₄ respectively corresponding to the pulse group _p 1 ~p ₄ is sequentially appear. _{The MCU 40 sequentially acquires the levels L 1 to} L ₄ appearing on the sensor electrode 30Y via the receiving unit 44, and stores them in the shift register 40a each time.

The specific contents of the levels L _{1 to} L ₄ will be described in detail by taking the case where _{the sensor electrode 30Y 1 shown in FIG. 5 is selected as an example.} In the following description, the capacitance formed between the respective sensor electrodes 30Y ₁ and four sensor electrodes _30X 1 _{~30X 4,} respectively and _C 11 _{-C 41.}

First, the _{level L 1} stored in the shift register 40a corresponding to the _{pulse group p 1} is a capacitance vector (C ₁₁ , C ₂₁ , C ₃₁ , C ₄₁ ) and a vector indicating the pulse group p ₁ (1, 1). , 1, 1). This inner product is _{calculated as C 11} + C ₂₁ + C ₃₁ + C ₄₁ , as also shown in FIG. _{Similarly, the level L 2} stored in the shift register 40a corresponding to the pulse group p ₂ is a capacitance vector (C ₁₁ , C ₂₁ , C ₃₁ , C ₄₁ ) and a vector indicating the pulse group p _{1 (1).} , 1, -1, become inner product of -1) is calculated as _{C 11 + C 21 -C 31 -C} 41, level _{L 3} stored in the shift register 40a in response to the pulse group _{p 3} is the capacitance (C ₁₁ , C ₂₁ , C ₃₁ , C ₄₁ ) and the vector (1, -1, -1, 1) indicating the _{pulse group p 3 are the inner product of C 11} −C ₂₁ −C ₃₁ + C. _{The level L 4} calculated as 41 and stored in the shift register 40a corresponding to the pulse group p ₄ is the capacitance vector (C ₁₁ , C ₂₁ , C ₃₁ , C ₄₁ ) and the vector indicating the _{pulse group p 4.} It becomes the inner product with (1, -1, 1, -1) and is calculated as _{C 11-} C ₂₁ + C _31- C _41.

The MCU 40 sequentially calculates the correlation values T _{1 to} T _{4 with the levels L 1 to} L ₄ accumulated in the shift register 40a for each of the _{four pulse groups p 1 to} p 4 using the correlator 40 b. As shown in FIG. 5, the specific contents of the _{correlation values T 1 to} T ₄ calculated in this way _{are 4C 11} , 4C ₂₁ , 4C ₃₁ , and 4C ₄₁ , respectively. That is, the correlation value _T 1 through T _4, the sensor electrode _30X 1 _{~30X 4} respectively, the change in capacitance formed at the intersection of the sensor electrode 30Y ₁ is to be reflected. Therefore, the MCU 40 can detect the position of the finger 4 by referring to the _{correlation values T 1 to} T ₄ calculated for each sensor electrode 30Y. Specifically, a region in the touch surface 3a in which the change in capacitance is equal to or greater than a predetermined value may be determined, and for example, the center position thereof may be detected as the position of the finger 4.

The position detection process of the finger 4 executed by the MCU 40 has been described in detail above. Next, returning to FIG. 4, the logic unit 41 controls the switch 58x so that the D terminal is connected to the common terminal at the timing of applying the pixel drive voltage Vcom. As a result, the pixel drive voltage Vcom is supplied to each of the plurality of sensor electrodes 30X, and the pixel drive operation can be executed.

The receiving unit 44 is a circuit that receives the downlink signal DS transmitted by the active pen 2 or the finger detection signal FDS transmitted by the transmitting unit 42 based on the control signal ctrl_r of the logic unit 41. Specifically, it includes an amplifier circuit 55, a detection circuit 56, and an analog-to-digital (AD) converter 57.

The amplifier circuit 55 amplifies and outputs the downlink signal DS or the finger detection signal FDS supplied from the selection unit 45. The detection circuit 56 is a circuit that generates a voltage corresponding to the level of the output signal of the amplifier circuit 55. The AD converter 57 is a circuit that generates a digital signal by sampling the voltage output from the detection circuit 56 at predetermined time intervals. The digital signal output by the AD converter 57 is supplied to the MCU 40.

Based on the digital signal thus supplied, the MCU 40 detects the positions (coordinates x, y) of the finger 4 and the active pen 2 and acquires the data Res transmitted by the active pen 2. Specifically, with respect to first position of the finger 4, MCU 40, based on the supplied digital signal, each sensor electrode 30Y, acquires the level _L 1 ~L _K respectively correspond to the pulse group _p 1 ~p _K do. The method of detecting the position of the finger 4 from the level L ₁ ~L _K, is as described above with reference to FIG. Next, regarding the position of the active pen 2, the MCU 40 determines the level of the position signal at each intersection of the plurality of sensor electrodes 30X and 30Y based on the supplied digital signal, and is based on each determined level. Detects the position of the active pen 2. Finally, regarding the data Res, the MCU 40 acquires the data Res by decoding the digital signal supplied from the receiving unit 44. The MCU 40 is configured to output the positions (coordinates x, y) and data Res thus detected to the host processor 32.

Further, the MCU 40 determines the contact state of the active pen 2 with respect to the touch surface 3a based on the pen pressure data included in the acquired data Res, and determines that the active pen 2 has newly contacted the touch surface 3a ( That is, when the pen pressure changes from 0 to a positive value), the pen-down information IN-PROXY is output to the host processor 32, and it is determined that the active pen 2 is separated from the touch surface 3a (that is, the pen pressure is changed). When it changes from a positive value to 0), the pen-up information OUT-PROXY is configured to be output to the host processor 32. The pen-down information IN-PROXY and the pen-up information OUT-PROXY output in this way are used by the host processor 32 to recognize the start and end of the stroke.

The above is the outline of the configuration of the position detection system 1 according to the present embodiment. Subsequently, the detailed contents of the above-mentioned output position determination process and 1 / N process will be described in order.

First, the output position determination process will be described in detail.

FIG. 6A is a diagram showing a pen position table used in the output position determination process according to the present embodiment, and FIG. 6B is a diagram showing a touch used in the output position determination process according to the present embodiment. It is a figure which shows the position table. The MCU 40 uses these tables to determine the position to output to the host processor 32 after detecting one or more positions for each of the active pen 2 or the finger 4 by the above-mentioned processing.

As shown in FIG. 6A, the pen position table is a table that stores the candidate pen position cP [i], the confirmed pen position fP [i], and the valid flag in association with each other. On the other hand, the touch position table is a table that stores the candidate touch position cT [j], the confirmed touch position fT [j], the valid flag, and the area type in association with each other. However, i and j are integers of 0 or more, respectively. Further, the candidate pen position cP [i] is the position of the active pen 2 detected in step S2 of FIG. 3, and the candidate touch position cT [j] is based on the total detection data generated in step S7 of FIG. The position of the indicated finger 4. Other parameters will be described in the following description.

Here, before the content of the output position determination process is specifically described, the concept of this process will be described in detail with reference to FIG. 1 again.

In the example shown in FIG. 1, three types of objects, an active pen 2, a finger 4, and a hand 5 holding the active pen 2, are in contact with the touch surface 3a. In the position detection process of the finger 4, it is preferable that only the finger 4 is detected, but there is a possibility that the active pen 2 and the hand 5 are also detected. This is because the change in capacitance at the sensor electrodes 30X and 30Y may include the change in capacitance at the sensor electrodes 30X and 30Y due to the capacitance formed on the active pen 2 or the hand 5 and the sensor electrodes 30X and 30Y. On the other hand, in the position detection process of the active pen 2, it is preferable that only the active pen 2 is detected, but there is a possibility that the hand 5 is also detected. This passes not only the route from the tip of the active pen 2 to the touch surface 3a (arrow A in FIG. 1) but also the route via the hand 5 (arrow B in FIG. 1) from the active pen 2 to the tablet 3. This is because the downlink signal DS is transmitted to.

The MCU 40 obtains one or more candidate touch positions by the process shown in steps S5 to S7 of FIG. 3 (the process may be the process shown in step S105 of FIG. 2), and then first, the width of each candidate touch position (capacitance). The size of the area where the amount of change is equal to or greater than a predetermined amount) is determined. Then, the candidate touch positions whose determined size is equal to or larger than the predetermined size are excluded from the output target. In the example of FIG. 1, the contact position of the hand 5 is excluded here. Next, for each of the remaining candidate touch positions, it is determined by referring to the pen position table whether or not it was detected as the position of the active pen 2 in the position detection process of the immediately preceding active pen 2, and the detected candidate. Exclude the touch position from the output target. In the example of FIG. 1, the contact position of the active pen 2 is excluded here. The candidate touch positions remaining until the end are the positions output to the host processor 32 in step S9 of FIG. According to this, since the contact position of the hand 5 and the contact position of the active pen 2 are excluded from the output target, it is possible to correctly select and output only the position of the finger 4.

On the other hand, the MCU 40 acquires one or more candidate pen positions by the process shown in step S2 of FIG. 3, and then refers to the touch position table for each of the acquired one or more candidate pen positions, whereby the immediately preceding finger 4 It is determined whether or not the position was detected as the position of the finger 4 or the hand 5 in the position detection process of. Then, the candidate pen position determined to have been detected as the position of the hand 5 is excluded from the output target. In the example of FIG. 1, the contact position of the hand 5 is excluded here. The candidate pen positions not excluded here, that is, the candidate pen positions determined not to be detected and the candidate pen positions determined to have been detected as the finger 4 are output to the host processor 32 in step S4 of FIG. It will be the position to be. According to this, since the contact position of the hand 5 is excluded from the output target, it is possible to correctly select and output only the position of the active pen 2.

As described above, according to the position detection process according to the present embodiment, the positions of the active pen 2 and the finger 4 can be correctly selected and output to the host processor 32. Hereinafter, the specific contents of the output position determination process performed by the MCU 40 using the pen position table and the touch position table will be described in detail.

7 and 8 are diagrams showing an example of output position determination processing performed by the MCU 40 using the pen position table and the touch position table, respectively.

FIG. 7 shows an example of changes in the pen position table and the touch position table in time series when the position detection of the active pen 2 precedes. The MCU 40 according to this example stores two candidate pen positions cP [0] and cP [1] in the pen position candidate table as a result of performing the position detection process of the active pen 2 for the first time. Then, the candidate pen positions cP [0] and cP [1] are set in the corresponding confirmed pen positions fP [0] and fP [1], respectively, and the respective valid flags are set to "valid". The MCU 40 supplies each of the confirmed pen positions fP [0] and fP [1] for which "valid" is set to the host processor 32 as the detection position of the active pen 2. However, at this stage, the detection position may not be supplied to the host processor 32.

Next, the MCU 40 performs the first position detection process of the finger 4, and as a result, stores the three candidate touch positions cT [0] to cT [2] in the touch position candidate table. Then, first, the area of each candidate touch position cT [0] to cT [2] (the area of the region where the amount of change in capacitance is equal to or greater than a predetermined amount) is detected. Here, it is assumed that the area larger than the predetermined size is detected only for the candidate touch position cT [1], and the area smaller than the predetermined size is detected for the other candidate touch positions cT [0] and cT [2]. The MCU40 sets the candidate touch position cT [1] to the confirmed touch position fT [1], sets the corresponding valid flag to "invalid", and further sets "palm (meaning palm)" to the corresponding area type. do.

Next, the MCU 40 determines the fixed pen positions fP [0] and fP [1] stored in the pen position candidate table for each of the candidate touch positions cT [0] and cT [2] in which the area smaller than the predetermined size is detected. ] Is approximately equal to each of the above. The term "substantially equal" here means that the distance between one position and the other position is not more than a predetermined value sufficiently smaller than the width of the touch surface 3a. The specific value of this predetermined value is preferably, for example, the length of several pixels.

In the example of FIG. 7, it is determined that the candidate touch position cT [0] is substantially equal to the confirmed pen position fP [0], and the candidate touch position cT [2] is any of the confirmed pen positions fP [0] and fP [1]. It is judged that they are not equal to each other. In this case, the MCU 40 sets the candidate touch position cT [2] in the confirmation pen position fP [2], sets the corresponding valid flag to "valid", and further sets the corresponding area type to "finger". On the other hand, nothing is set in the confirmation pen position fP [0] (the initial value is NULL), and the corresponding valid flag is set to "invalid". The area type corresponding to the confirmation pen position fP [0] is left at the initial value (without setting anything).

After setting the touch position candidate table as described above, the MCU 40 supplies only the confirmed touch position fT [2] whose corresponding valid flag is "valid" to the host processor 32 as the detection position of the finger 4. do. The candidate touch position cT [0], which is located in the vicinity of the confirmation pen position fP [0] and whose detected width is less than the predetermined size, is not supplied to the host processor 32.

Next, the MCU 40 resets the pen position candidate table once, and then performs a second position detection process of the active pen 2. Here, assuming that none of the active pen 2, the finger 4, and the hand 5 is moving on the touch surface 3a, as a result of the position detection, the two candidate pen positions cP [0] and cP [1] are the same as in the first time. ] Will be stored in the pen position candidate table.

Then, whether or not the MCU 40 is substantially equal to each of the confirmed touch positions fT [0] to fT [2] stored in the touch position candidate table for each of the acquired candidate pen positions cP [0] and cP [1]. Is determined. In the example of FIG. 7, since NULL is set to the confirmed touch position fT [0] at this point, whether or not they are substantially equal to each of the confirmed touch positions fT [1] and fT [2]. It becomes a judgment.

In the example of FIG. 7, it is determined that the candidate pen position cP [1] is substantially equal to the confirmed touch position fT [1], and the candidate pen position cP [0] is any of the confirmed touch positions fT [0] to fT [2]. It is judged that they are not equal to each other. In this case, the MCU 40 first sets the candidate pen position cP [0] to the fixed pen position fP [0], and sets the corresponding valid flag to "valid". On the other hand, for the candidate pen position cP [1], it is determined whether the area type of the corresponding confirmed touch position fT [1] is "palm" or "finger". If the result of the determination is "palm", NULL is set in the confirmation pen position fP [1] and the corresponding valid flag is set to "invalid". On the other hand, if the result of the determination is "finger", the candidate pen position cP [1] is set in the confirmed pen position fP [1], and the corresponding valid flag is set to "valid". In the example of FIG. 7, since the area type of the confirmed touch position fT [1] is “palm”, NULL is set in the corresponding confirmed pen position fP [1].

FIG. 8 shows an example of changes in the pen position table and the touch position table in time series when the position detection of the finger 4 precedes. The MCU 40 according to this example stores three candidate touch positions cT [0] to cT [2] in the touch position candidate table as a result of performing the position detection process of the finger 4 for the first time. Subsequently, the MCU 40 detects the size of each candidate touch position cT [0] to cT [2] (the size of the region where the amount of change in capacitance is equal to or greater than a predetermined amount). Here, assuming that the area larger than the predetermined size is detected only for the candidate touch position cT [1] as in the example of FIG. 7, the MCU 40 first sets the candidate touch position cT [1] to the confirmed touch position fT [1]. While setting, set the corresponding valid flag to "invalid" and set the corresponding area type to "palm". On the other hand, for the other two candidate touch positions cT [0] and cT [2], the candidate touch positions cT [0] and cT [2] are set in the confirmed touch positions fT [0] and fT [2], respectively. At the same time, the corresponding valid flag is set to "valid", and the corresponding area type is set to "finger". The MCU 40 supplies each of the confirmed touch positions fT [0] and fT [2] for which "valid" is set to the host processor 32 as the detection position of the finger 4. However, at this stage, the detection position may not be supplied to the host processor 32.

Next, the MCU 40 performs the position detection process of the active pen 2 for the first time, and as a result, stores the two candidate pen positions cP [0] and cP [1] in the pen position candidate table. Then, whether or not the MCU 40 is substantially equal to each of the confirmed pen positions fT [0] to fT [2] stored in the touch position candidate table for each of the acquired candidate pen positions cP [0] and cP [1]. Is determined.

In the example of FIG. 8, it is determined that the candidate pen position cP [0] is substantially equal to the confirmed touch position fT [0], and the candidate pen position cP [1] is determined to be substantially equal to the confirmed touch position fT [1]. It will be. Next, the MCU 40 determines whether the area type of each of the confirmed touch positions fT [0] and fT [1] is "palm" or "finger". In the example of FIG. 8, the area type of the confirmed touch position fT [0] is determined to be "finger", and the area type of the confirmed touch position fT [1] is determined to be "palm".

The MCU 40 sets NULL for the confirmed pen position fP [1] for the candidate pen position cP [1] determined that the area type of the corresponding confirmed touch position fT [1] is "palm", and corresponds to the effective. Set the flag to "invalid". On the other hand, for the candidate pen position cP [0] for which the area type of the corresponding confirmed touch position fT [0] is determined to be "finger", the candidate pen position cP [0] is set in the confirmed pen position fP [0]. At the same time, the corresponding valid flag is set to "valid". This process means that it is considered that there is an error in the position detection process of the finger 4. The MCU 40 supplies the confirmed pen position fP [0] for which "valid" is set to the host processor 32 as the detection position of the active pen 2.

Next, the MCU 40 resets the touch position candidate table once, and then performs the second position detection process of the finger 4. Here, assuming that none of the active pen 2, the finger 4, and the hand 5 is moving on the touch surface 3a, as a result of the position detection, the three candidate touch positions cT [0] to cT [2] are the same as in the first time. ] Will be stored in the touch position candidate table.

The MCU 40 in which the candidate touch positions cT [0] to cT [2] are stored in the touch position candidate table is next, and the width of each candidate touch position cT [0] to cT [2] (the amount of change in capacitance is a predetermined amount). The size of the above area) is detected. Here, assuming that the area larger than the predetermined size is detected only for the candidate touch position cT [1] as in the first detection, the candidate touch position cT [1] is set for the confirmed touch position fT [1]. At the same time, the corresponding valid flag is set to "invalid", and the corresponding area type is set to "palm". This process is the same as the process performed after the first position detection of the finger 4.

Next, whether or not the MCU 40 is substantially equal to each of the confirmed pen positions fP [0] and fP [1] stored in the pen position candidate table for each of the remaining candidate touch positions cT [0] and cT [2]. Is determined. In the example of FIG. 8, it is determined by this determination that the candidate touch position cT [0] is substantially equal to the confirmed pen position fP [0], and the candidate touch position cT [2] is the confirmed pen position fP [0], fP [ It is determined that none of 1] is equal. In this case, the MCU 40 sets the candidate touch position cT [2] in the confirmation pen position fP [2], sets the corresponding valid flag to "valid", and further sets the corresponding area type to "finger". On the other hand, nothing is set in the confirmation pen position fP [0] (the initial value is NULL), and the corresponding valid flag is set to "invalid". The area type corresponding to the confirmation pen position fP [0] is left at the initial value (without setting anything).

After setting the touch position candidate table as described above, the MCU 40 supplies only the confirmed touch position fT [2] whose corresponding valid flag is "valid" to the host processor 32 as the detection position of the finger 4. do.

As described above, according to the output position determination process according to the present embodiment, the contact position of the hand 5 can be excluded from the output target in the pen position determination process, and is active in the passive pointer position determination process. The contact positions of the pen 2 and the hand 5 can be excluded from the output target. Therefore, even if the contact position of the active pen 2 and the contact position of the finger 4 are erroneously recognized at the stage of the candidate pen position and the candidate touch position, the active pen 2 and the finger 4 are finally recognized. The position can be correctly output to the host processor 32.

Next, the output position determination process performed by the MCU 40 using the pen position table and the touch position table will be described in more detail again from another viewpoint with reference to the process flow of the MCU 40.

9 and 10 are views showing the details of the flow chart shown in FIG. First, referring to FIG. 9, the MCU 40 first performs detection of the active pen 2 (step S21) and determines whether or not the active pen 2 is detected as a result (step S22). The process of step S2 shown is executed. If it is determined that the finger 4 has not been detected in step S22, the process proceeds to step S51 in FIG. 10 to start the position detection process of the finger 4.

On the other hand, if it is determined that the detection is detected in step S22, the MCU 40 executes the pen position determination process shown in step S3 of FIG. Specifically, first, the pen position table is reset (step S31). In the pen position table after reset, no candidate pen position cP [i] is set. Subsequently, the MCU 40 acquires I (I is an integer of 1 or more) candidate pen positions cP [i] (i = 0 to I-1) detected in step S21 and sets them in the pen position table (). Step S32). Then, the processes of steps S34 to S36 are sequentially performed for all i (step S33).

Specifically, the MCU 40 first determines whether or not the confirmed touch position fT [j] equal to the candidate pen position cP [i] is stored in the touch position table (step S34). As a result, when it is determined that the pen position is stored, the area type stored in the touch position table is "finger" or "palm" for the confirmed touch position fT [j] which is substantially equal to the candidate pen position cP [i]. Which is determined (step S35).

When it is determined in step S34 that the pen is not stored, and when it is determined in step S35 that the pen is a "finger", the MCU 40 sets the candidate pen position cP [i] in the confirmed pen position fP [i] and sets the candidate pen position cP [i]. “Valid” is set in the corresponding valid flag (step S36). On the other hand, if it is determined in step S35 that it is "palm", the process of step S36 is not performed, and as a result, NULL is set for the corresponding confirmed pen position fP [i] and "invalid" is set for the corresponding valid flag. Each is set.

When the processing of steps S34 to S36 is completed for all i, the MCU 40 sets only the confirmed pen position fP [i] in which the corresponding valid flag is "valid" as the detection position of the active pen 2 in the host processor 32. Output (step S4), and then start the position detection process of the finger 4.

Specifically, as shown in FIG. 10, the finger 4 is detected (step S51), and as a result, it is determined whether or not the finger 4 is detected (step S52), as shown in FIG. The processing of steps S5 to S7 is executed. Although the processing of steps S5 to S7 is executed here, the processing of step S105 of FIG. 2 may be executed. However, in this case, in order to secure the detection rate of the active pen 2, it is necessary to perform the processes of steps S2 to S4 twice in succession. If it is determined that the detection has not been performed in step S52, the process proceeds to step S21 of FIG. 9 to start the position detection process of the active pen 2.

On the other hand, if it is determined that the detection is detected in step S52, the MCU 40 executes the passive pointer position determination process shown in step S8 of FIG. Specifically, first, the touch position table is reset (step S81). In the touch position table after reset, no candidate touch position cT [j] is set. Subsequently, the MCU 40 acquires J candidate touch positions cT [j] (j = 0 to J-1) detected in step S51 (J is an integer of 1 or more) and sets them in the touch position table (). Step S82). Then, the processes of steps S84 to S87 are sequentially performed for all j (step S83).

Specifically, the MCU 40 first calculates the area of the candidate touch position cT [j]. The area calculated here is the area of the region including the candidate touch position cT [j] and the change amount of the capacitance is a predetermined amount or more. Then, it is determined whether or not the calculated area is equal to or larger than a predetermined size (step S84).

When it is determined in step S84 that the size is larger than the predetermined size (that is, when it is determined that the area = large), the MCU 40 sets the candidate touch position cT [j] in the confirmed touch position fT [j] and corresponds to it. "Invalid" is set in the valid flag to be set, and "palm" is set in the corresponding area type (step S85).

On the other hand, when it is determined in step S84 that the size is not larger than the predetermined size (that is, when it is determined that the area = small), the MCU 40 subsequently has a fixed pen position fP [i] substantially equal to the candidate touch position cT [j]. It is determined whether or not it is stored in the pen position table (step S86). As a result, when it is determined that it is not stored, the MCU 40 sets the candidate touch position cT [j] in the confirmed touch position fT [j], "valid" in the corresponding valid flag, and "valid" in the corresponding area type. Each of the "fingers" is set (step S87). On the other hand, when it is determined that the storage is stored in step S86, the MCU 40 does not perform the processing of step S87, and as a result, NULL is set for the corresponding confirmed touch position fT [j] and "invalid" is set for the corresponding valid flag. Each is set.

When the processing of steps S15 to S18 is completed for all i, the MCU 40 outputs only the confirmed touch position fT [j] for which the corresponding valid flag is "valid" to the host processor 32 as the detection position of the finger 4. (Step S9), and then the process returns to step S2 to start the position detection process of the active pen 2.

As described above, the output position determination process performed by the MCU 40 using the pen position table and the touch position table has been described in more detail again with reference to the processing flow of the MCU 40. Here, various modifications can be considered for the output position determination process according to the present embodiment. Therefore, in the following, as a modification of the output position determination process according to the present embodiment, the first to fourth modifications will be described.

The first modification relates to the pen position determination process. In the MCU 40 according to this modification, when a plurality of positions where the downlink signal DS level is equal to or higher than a predetermined level are detected, the position where the downlink signal DS level is the highest is set as the position of the active pen 2 in the host processor 32. Configured to output. In the example of FIG. 7, the level of the downlink signal DS at the candidate pen position cP [1] detected by the downlink signal DS received through the user's hand 5 is usually directly from the pen electrode of the active pen 2. It is smaller than the level of the downlink signal DS at the candidate pen position cP [0] detected by the received downlink signal DS. Therefore, the MCU 40 outputs the candidate pen position cP [0] to the host processor 32 as the position of the active pen 2. This result is the same as that of the above embodiment. Therefore, it can be said that the MCU 40 can correctly output the position of the active pen 2 to the host processor 32 even by this modification.

The second modification also relates to the pen position determination process. The MCU 40 according to this modification is the area of a region where the levels of the downlink signal DS having the predetermined level or higher are continuous when a plurality of positions where the level of the downlink signal DS is equal to or higher than the predetermined level are detected at a distance. Is configured to detect the position of the active pen 2. More specifically, the position having the smaller area is detected as the position of the active pen 2. In the example of FIG. 7, the area of the candidate pen position cP [1] detected by the downlink signal DS received through the user's hand 5 is the downlink directly received from the pen electrode of the active pen 2. The area is larger than the area of the candidate pen position cP [0] detected by the signal DS. Therefore, the MCU 40 outputs the candidate pen position cP [0] to the host processor 32 as the position of the active pen 2. This result is also the same as that of the above embodiment. Therefore, it can be said that the MCU 40 can correctly output the position of the active pen 2 to the host processor 32 even by this modification.

The third modification relates to the passive pointer position determination process. The MCU 40 according to this modification serves as a reference for determination (palm determination) in step S15 shown in FIG. 10, depending on whether or not the position of the active pen 2 is detected by the position detection process of the active pen 2 immediately before. It is configured to change the predetermined size. More specifically, when one or more pen positions are output by the immediately preceding pen detection step (see FIG. 3), the predetermined size is reduced. For example, if the position of the active pen 2 is not detected by the position detection process of the immediately preceding active pen 2, the predetermined size is set to 20 mm, and the position of the active pen 2 is one or more by the position detection process of the immediately preceding active pen 2. If it is detected, it is conceivable that the predetermined size is 16 mm. This change process is for making it possible to more quickly distinguish between the active pen 2 and the hand 5 when the active pen 2 is detected. That is, it takes a certain amount of time for the hand 5 to come into contact with the touch surface 3a, and there may be a timing when the contact area between the hand 5 and the touch surface 3a is small within that time, so that the finger 4 In the position detection process of the above, when determining whether the palm or the finger is determined by the area determination, it may occur that the contact position of the hand 5 is erroneously determined as the contact position of the finger 4. According to this modification, since the predetermined size is reduced as described above, it is possible to reduce the possibility that such an erroneous determination occurs when the active pen 2 is detected.

Here, according to the position detection process of the active pen 2 described above, the position of the active pen 2 can be detected even in a state where the active pen 2 is not in contact with the touch surface 3a (hover state). This is because the MCU 40 can detect the downlink signal DS even in the hover state if the active pen 2 is closer to the touch surface 3a to some extent. According to the third modification, the predetermined size can be reduced while the active pen 2 approaching the touch surface 3a is in the hover state, so that the possibility of the above-mentioned erroneous determination is reduced. In this state, it becomes possible to reach the timing when the active pen 2 comes into contact with the touch surface 3a.

FIG. 11 is a flow chart showing a pointer position detection process executed by the sensor controller 31 according to the fourth modification. The figure shows a modified example of the flow chart shown in FIG.

The difference between FIGS. 11 and 9 is that step S37 is executed after determining that it is a "palm" in step S35. More specifically, in the MCU 40 according to this modification, whether or not the pen position (specifically, the candidate pen position cP [i]) detected this time in step S35 exists in the vicinity of the palm region (that is, the candidate pen position). For the fixed touch position fT [j] that is almost equal to cP [i], it is determined whether the area type stored in the touch position table is "finger" or "palm"), and it is determined that it exists in the vicinity of the palm area. (That is, when it is determined that the area type is "palm"), the pen pressure indicated by the pen pressure data included in the data Res output in the previous pen detection step (previously detected pen pressure). Is valid (pen pressure> 0) or invalid (pen pressure = 0) (step S37). If it is determined to be valid, the process is transferred to step S36, the candidate pen position cP [i] is set to the confirmed pen position fP [i], and the corresponding valid flag is set to "valid" (step S36). ). On the other hand, if it is determined to be invalid, the process of step S36 is not performed. In this case, the corresponding confirmation pen position fP [i] is set to NULL, and the corresponding valid flag is set to "invalid".

According to the fourth modification, it is possible to prevent the drawing line from disappearing in the vicinity of the palm region when the user performs an input operation with the active pen 2. That is, according to the processing flow of FIG. 9, when the pen tip approaches the palm area when the user performs an input operation with the active pen, it is determined as "palm" by step S35, and the fixed pen position fP [i] is reached. The candidate pen position cP [i] is no longer set. Then, the coordinates are not output to the host processor 32, and the drawing line is interrupted. However, even if the pen tip approaches the palm area, it is preferable that the drawing line is not interrupted as long as the user continues to perform the input operation. According to the fourth modification, since it is determined in step S37 whether the pen pressure detected last time is valid or invalid, it is determined whether or not the user is continuously performing the input operation. can do. As a result, the coordinate output to the host processor 32 can be continued when the user continues to perform the input operation, so that when the user performs the input operation with the active pen 2, the drawing line is drawn in the vicinity of the palm area. It becomes possible to prevent it from disappearing.

Next, the 1 / N process will be described in detail. In the following, first, the problems of the background technology corresponding to the 1 / N processing and the effects produced by the introduction of the 1 / N processing will be described in more detail, and then the contents of the 1 / N processing will be described in detail.

FIG. 12 (a) is a diagram showing a control sequence related to the pointer position detection process according to the background technique of the present invention, and FIG. 12 (b) shows a control sequence related to the pointer position detection process according to the present embodiment. It is a figure which shows. In these figures, "T" indicates a period during which the MCU 40 performs the position detection process of the finger 4, and "P" indicates a period during which the MCU 40 performs the position detection process of the active pen 2.

As shown in FIG. 12 (a), the MCU 40 according to the background technique of the present invention performs the position detection process of the active pen 2 twice in succession, which requires 3 milliseconds each time, and then takes 2 milliseconds each time. It is configured to repeat the position detection process of the finger 4 and the active pen 2 with the rhythm of performing the required position detection process of the finger 4 once. In this case, the detection rate of the finger 4 is 125 (= 1/8 × 1000) times / sec, and the detection rate of the active pen 2 is 250 (= 2/8 × 1000) times / sec. By doing so, the detection rate of the active pen 2 can be improved. However, according to this position detection process, since the detection interval of the active pen 2 is not constant, it is expected that the coordinate data of the active pen 2, which is sequentially output from the sensor controller 31, is transmitted at equal intervals in time. In a drawing application or the like that operates as a result, there is a problem that the drawing result becomes unnatural.

On the other hand, in the MCU 40 according to the present embodiment, as shown in FIG. 12 (b), the finger 4 (first detection rate) is performed at a rate of 250 (= 1/4 × 1000) times / second (first detection rate). The 1 / N process of the position detection process (first detection process) of the pointer) is executed. In FIG. 12 (b), N = 2, and in this case, the time required to execute this 1 / N process is the time required for the position detection process of the finger 4 according to the example of FIG. 12 (a). It is 1/2, that is, 1 millisecond. Then, the MCU 40 acquires partial detection data indicating whether or not the finger 4 is present based on this 1 / N processing, and holds it in the shift register 40a shown in FIG. 5 (up to this point, the first detection). Step). The shift register 40a is configured to store the partial detection data for N times, and when the partial detection data is newly written to the shift register 40a, the partial detection data acquired N times before is erased.

Further, each time the MCU 40 newly holds the partial detection data in the memory, the MCU 40 synthesizes the partial detection data for N-1 pieces held in the memory up to that point and the newly held partial detection data. Generates total detection data indicating whether or not the finger 4 is present for the entire touch surface 3a (synthesis step). The generated total detection data is subjected to the correlation value calculation process (correlation value calculation step) described with reference to FIG. 5, and the first detection rate (250) as the passive pointer position from the MCU 40 to the host processor 32. It is output at (times / second) (report step).

The 1 / N processing is executed at a predetermined interval (specifically, an interval of 3 milliseconds), and in this interval, the position detection processing (second detection processing) of the active pen 2 (second pointer) is performed. Everything is done only once (second detection step). Therefore, the detection rate (second detection rate) of the position of the active pen 2 is a value equal to the first detection rate (250 times / sec). Although the detection of the active pen 2 is executed at equal intervals, this detection rate is the same as the detection rate of the active pen 2 according to the example of FIG. 12 (a).

As described above, according to the pointer position detection process according to the present embodiment, the finger 4 position detection process is executed in N times, so that the active pen 2 and the finger 4 are active while maintaining the detection rates of both. It becomes possible to execute the detection of the pen 2 at equal intervals. Therefore, the above-mentioned problem will be solved. Hereinafter, the contents of the 1 / N processing will be described in detail.

In the following description, the contents of the 1 / N process will be described with reference to the first to fifth examples. The 1 / N process according to the first to fourth examples detects 1 / N of the entire touch surface 3a (that is, detects a change in capacitance at the intersection of the sensor electrode 30X and the sensor electrode 30Y). For example, approximately 1 / N of a plurality of sensor electrodes 30X (first electrode) (see FIGS. 14 and 16 described later), or, for example, approximately 1 / N of a plurality of sensor electrodes 30Y (second electrode) (described later). (See FIGS. 15 and 17). Note that approximately 1 / N means that when 1 / N is not an integer, the number of sensor electrodes 30X or sensor electrodes 30Y used each time is adjusted so that it becomes an integer. On the other hand, in the 1 / N processing according to the fifth example, N × M pieces (M) constituting each of _{the 1 / N portions (specifically, the above-mentioned signals s 1 to s K) of the finger detection signal FDS.} = M of K / N) pulses) are used (see FIG. 18 described later). Each of them will be described in detail below. In the following, the case where N = 2 and the sensor 30 of 16 × 16 is used will be described as an example, but the case where N ≧ 3 or the size of the sensor 30 is not 16 × 16 will be described. Is the same.

First, FIG. 13 is a diagram showing an example of a finger detection signal FDS used together with a 16 × 16 sensor 30. As shown in the figure, the signal FDS for finger detection in this case is composed of sixteen pulse group _p 1 _{~p 16.} Further, each of the pulse group _p 1 _{~p 16} is configured to include a pulse represented by "1" or "-1" 16.

As described above, the MCU 40 and the logic unit 41 select one sensor electrode 30Y, and cause the transmission unit 42 _{to sequentially input each pulse group pn} (n = 1 to 16) to each sensor electrode 30X. It is configured to repeat for each sensor electrode 30Y. _{Therefore, assuming that} the time required for processing one pulse group pn is t, the time required for performing the position detection process of the finger 4 (here, the position detection process executed in step S105 shown in FIG. 2). is a t × 16 (= the total number of pulse group _{p n)} × 16 (= the total number of the sensor electrodes 30Y).

14 is a diagram showing a first example of the contents of the 1 / N process, FIG. 14 (a) shows the first process, and FIG. 14 (b) shows the second process. In this example, 1 / N processing is performed using eight different sensor electrodes 30X in each of the first and second times. More specifically, 16 sensor electrodes 30X aligned in the X direction are selected every other time and used in the first process, and the remaining sensor electrodes 30X are used in the second process. ..

According to this first embodiment, since the number of sensor electrodes 30X as an input target finger detecting signal FDS in a single process is 8, a finger detected by only eight pulse group p ₁ ~p ₈ It becomes possible to configure the signal FDS. Accordingly, examples of since the one process (total = pulse group _{p n)} time t × 8 necessary for performing × 16 (= the total number of the sensor electrodes 30Y), Figure 2 or Figure 12 (a) It is possible to complete one process in half the time as compared with the position detection process by.

Further, according to the first example, since all the sensor electrodes 30X are covered by the first and second times, the MCU 40 is held in the shift register 40a (see FIG. 5) as a result of the first processing. By synthesizing the partial detection data obtained and the partial detection data held in the shift register 40a as a result of the second processing, total detection data indicating whether or not the finger 4 is present on the entire touch surface 3a is generated. It will be possible to do.

Further, according to the first example, since there is no order between the first time and the second time, when the partial detection data is newly acquired, the MCU 40 performs 1 / N processing each time, and the shift register is registered. It becomes possible to generate total detection data by synthesizing with the partial detection data for N-1 times stored in 40a. That is, not only the partial detection data held in the shift register 40a as a result of the first processing and the partial detection data held in the shift register 40a as a result of the second processing executed immediately after that are combined. The total detection data can also be obtained by synthesizing the partial detection data held in the shift register 40a as a result of the second processing and the partial detection data held in the shift register 40a as a result of the first processing executed immediately after that. Can be generated. Therefore, it is possible to output the detection result of the finger 4 at a detection rate twice as high as the detection rate of the finger 4 according to the example of FIG. 2 or FIG. 12 (a).

15 is a diagram showing a second example of the contents of the 1 / N process, FIG. 15 (a) shows the first process, and FIG. 15 (b) shows the second process. In this example, 1 / N processing is performed using eight different sensor electrodes 30Y in each of the first and second times. More specifically, 16 sensor electrodes 30Y aligned in the Y direction are selected every other time and used in the first process, and the remaining sensor electrodes 30Y are used in the second process. ..

According to this second example, the number of sensor electrodes 30Y to be selected in one process is eight. Accordingly, examples of since once (total = pulse group _{p n)} time t × 16 required to process performing the × 8 (= the total number of the sensor electrodes 30Y), Figure 2 or Figure 12 (a) It is possible to complete one detection operation in half the time as compared with the position detection process by.

Further, since the second example also covers all the sensor electrodes 30Y in the first and second times, the MCU 40 is held in the shift register 40a as a result of the first processing as in the first example. By synthesizing the partial detection data obtained and the partial detection data held in the shift register 40a as a result of the second processing, total detection data indicating whether or not the finger 4 is present on the entire touch surface 3a is generated. It will be possible to do.

Further, also in the second example, since there is no order between the first time and the second time, the MCU 40 is set to the detection rate of the finger 4 according to the example of FIG. 2 or FIG. 12 (a) as in the first example. It is possible to output the detection result of the finger 4 at a detection rate twice as high as that of the finger 4.

16A and 16B are views showing a third example of the contents of the 1 / N process, FIG. 16A shows the first process, and FIG. 16B shows the second process. In this example, as in the first example, 1 / N processing is performed using eight different sensor electrodes 30X in each of the first and second times. However, in this example, eight of the 16 sensor electrodes 30X to be aligned are selected in order from one end and used in the first process, and the remaining sensor electrodes 30X are used in the second process. There is.

Also in this third example, for the same reason as in the first example, one process can be completed in half the time as compared with the position detection process according to the example of FIG. 2 or FIG. 12 (a). Will be possible. In addition, it becomes possible to generate total detection data indicating whether or not the finger 4 is present on the entire touch surface 3a. Further, the detection result of the finger 4 can be output at a detection rate twice as high as the detection rate of the finger 4 according to the example of FIG. 2 or FIG. 12 (a).

FIG. 17 is a diagram showing a fourth example of the contents of the 1 / N process, FIG. 17 (a) shows the first process, and FIG. 17 (b) shows the second process. In this example, as in the second example, 1 / N processing is performed using eight different sensor electrodes 30Y in each of the first and second times. However, in this example, eight of the 16 sensor electrodes 30Y to be aligned are selected in order from one end and used in the first process, and the remaining sensor electrodes 30Y are used in the second process. There is.

Also in this fourth example, for the same reason as in the second example, one process is completed in half the time as compared with the position detection process according to the example of FIG. 2 or FIG. 12 (a). Will be possible. In addition, it becomes possible to generate total detection data indicating whether or not the finger 4 is present on the entire touch surface 3a. Further, the detection result of the finger 4 can be output at a detection rate twice as high as the detection rate of the finger 4 according to the example of FIG. 2 or FIG. 12 (a).

FIG. 18 is a diagram showing a fifth example of the contents of the 1 / N process, FIG. 18 (a) shows the first process, and FIG. 18 (b) shows the second process. In this example, only half of the 16 in the first process of pulses group p ₁ ~p ₁₆ is used, the remainder in the process of the second is used. More specifically, the pulse group _p 1 ~p ₈ in the first process of is used, the pulse group _p 9 _{~p 16} is used in the processing of the second time.

According to this fifth example, the number of pulses input to each sensor electrode 30X in one process is only eight. Accordingly, examples of since the one (total = pulse group _{p n)} processing time required to perform the t × 8 × 16 (= the total number of the sensor electrodes 30Y), Figure 2 or Figure 12 (a) It is possible to complete one detection operation in half the time as compared with the position detection process by.

In addition, according to the fifth embodiment, it means to cover all the first and second times with 16 pulse groups _p 1 _{~p 16,} similarly to the first to fourth example, the MCU 40, 1 By synthesizing the partial detection data held in the shift register 40a as a result of the second processing and the partial detection data held in the shift register 40a as a result of the second processing, the finger 4 exists for the entire touch surface 3a. It becomes possible to generate whole detection data indicating whether or not to do so.

Further, also in the fifth example, since there is no order between the first and second times, the MCU 40 is the finger 4 according to the example of FIG. 2 or FIG. 12 (a) as in the first to fourth examples. It is possible to output the detection result of the finger 4 at a detection rate twice that of the detection rate.

19 and 20 are diagrams showing an example of specific storage contents of the shift register 40a (see FIG. 5) in the fifth example. In the figure, the stored contents of the shift register 40a are displayed side by side corresponding to each sensor electrode 30Y for easy understanding. Further, the numerical value shown in the sensor 30 in the figure shows the value of the capacitance at each intersection of the sensor electrodes 30X and 30Y. Hereinafter, the method of generating the total detection data in the fifth example will be specifically described with reference to FIGS. 19 and 20.

FIG. 19 shows the stored contents of the shift register 40a immediately after the first processing is completed. In the first process, the level _L 1 ~L ₈ is stored in the shift register 40a for each sensor electrode 30Y. When the first processing for a certain sensor electrode 30Y is completed, the shift register 40a is stored in the shift register 40a in the second processing performed immediately before the sensor electrode 30Y, as shown in FIG. Levels L _{9 to} L ₁₆ remain. Therefore, the MCU 40 synthesizes _{the newly stored partial detection data represented by the levels L 1 to} L ₈ and the partial detection data represented by the levels L _{9 to} L _{16 remaining in the shift register 40a.} Two whole detection data are used, and the above-mentioned correlation value is calculated using this whole detection data. As a result, the MCU 40 can output the coordinates indicating the position of the finger 4 to the host processor 32 when the first detection operation is completed.

FIG. 20 shows the stored contents of the shift register 40a immediately after the second processing is completed. In the second process, the levels L _{9 to} L ₁₆ are stored in the shift register 40a for each sensor electrode 30Y. When the second processing for a certain sensor electrode 30Y is completed, the shift register 40a is stored in the shift register 40a in the first processing performed immediately before the sensor electrode 30Y, as shown in FIG. Levels L _{1 to} L ₈ remain. Therefore, the MCU 40 synthesizes _{the newly stored partial detection data represented by the levels L 9 to} L ₁₆ and the partial detection data represented by the levels L _{1 to} L _{8 remaining in the shift register 40a.} Two whole detection data are used, and the above-mentioned correlation value is calculated using this whole detection data. As a result, the MCU 40 can output the coordinates indicating the position of the finger 4 to the host processor 32 even when the second detection operation is completed.

As described above, according to the pointer position detection process according to the present embodiment, the finger 4 position detection process is executed in N times, so that the detection rates of both the active pen 2 and the finger 4 are maintained. , It becomes possible to execute the detection of the active pen 2 at equal intervals. Therefore, since the detection interval of the active pen 2 is not constant, for example, a drawing application that operates with the expectation that the coordinate data of the active pen 2 sequentially output from the sensor controller 31 is transmitted at equal intervals in time. In, the problem of the background technique that the drawing result becomes unnatural is solved. Further, according to the position detection process according to the present embodiment, the finger 4 can be detected at a detection rate higher than that of the background technique.

Next, the position detection system 1 according to the second embodiment of the present invention will be described. The position detection system 1 according to the present embodiment adds a function to the position detection system 1 according to the first embodiment to prevent an unnecessary straight line from being drawn due to the presence of the ghost position described above. Is. Hereinafter, the same configurations as those of the first embodiment are designated by the same reference numerals, and the differences from the first embodiment will be described.

FIG. 22 is a diagram showing an example of a usage state of the position detection system 1 according to the present embodiment. Further, FIG. 23 is a diagram illustrating the operation of the host processor 32 according to the background technology of the present embodiment. Hereinafter, the problems of the present embodiment will be described with reference to FIGS. 22 and 23, and then the operation of the sensor controller 31 according to the present embodiment will be described.

As shown in FIG. 22, when performing an input operation with the active pen 2, the user holds a hand (hereinafter referred to as a left hand) opposite to the hand holding the active pen 2 (hereinafter referred to as a right hand). It may be attached to the touch surface 3a. In this case, the contact position of the left hand (Palm area Palm in the figure) is excluded from both the touch position and the pen position by the process shown in the first embodiment, but separately, the lower part of the left arm. The pen position (ghost position G shown in the figure) may be detected. This forms the current path CR (current path from the pen electrode of the active pen 2 through the sensor electrode 30X to the left arm and back to the active pen 2 via the human body), and as a result, the left arm. This is because the transmission signal of the active pen 2 is detected below. Although FIG. 22 shows an example of the sensor electrode 30X, the same applies to the sensor electrode 30Y.

The level of the signal detected at the ghost position G is smaller than the level of the signal detected at the contact position of the active pen 2 (pen position P in the figure), and the active pen 2 that can be simultaneously detected by the tablet 3 is usually Since there is only one, this ghost position G does not matter as long as the active pen 2 is in contact with the touch surface 3a. However, for example, when the active pen 2 suddenly moves from the bezel region 3b of the tablet 3 into the touch surface 3a along the illustrated arrow A, the sensor controller 31 before detecting the actual pen position P. , The ghost position G may be detected.

In FIG. 23, the ghost position G first detected in such a case is designated as the _n-1st fixed pen position fP n-1, and the detected pen position P is designated as the _{nth fixed pen position fP n.} Each is illustrated. When the fixed pen positions fP _n-1 and fP _n are detected one after another in this way, the host processor 32 receiving these supplies draws a line segment L between them as shown in FIG. 23. .. Since this line segment L is not intended by the user, it is necessary to prevent the line segment L from being drawn. This is the subject of this embodiment. Hereinafter, the operation of the sensor controller 31 for solving this problem will be described in detail with reference to FIG. 24.

FIG. 24 is a flow chart showing a pointer position detection process executed by the sensor controller 31 according to the present embodiment. In the figure, steps S101 to S107 are added to the pen detection step shown in FIG. Hereinafter, the operation of the sensor controller 31 according to the present embodiment will be described in detail with reference to FIG. 24 and FIG. 23 again.

In the sensor controller 31 (specifically, the MCU 40 shown in FIG. 4) according to the present embodiment, after the pen position is determined in step S3, the area type is set to palm in the immediately preceding touch detection step (see FIG. 3). It is determined whether or not the touch position has been detected (step S101). When it is determined that the sensor controller 31 has not been detected, the sensor controller 31 stores the determined pen position separately from the pen position table described above (step S107), and then performs the output process of step S4. On the other hand, when it is determined that the sensor controller 31 has been detected, the pen position (previous pen position) stored in the previous step S106 is then set within a predetermined area based on the detected palm area Palm. It is determined whether or not the position is located (step S102).

FIG. 23 shows an example of this predetermined region. The sensor controller 31 acquires the spread of the palm region Palm from the correlation value described with reference to FIG. 5, and based on the result, in the touch surface 3a corresponding to the sensor electrodes 30X and 30Y passing through the palm region Palm. It is configured to acquire the cross-shaped region (cross region XR) of. The predetermined area is composed of the cross area XR thus acquired.

Returning to FIG. 24, the sensor controller 31 subsequently determines the level of the transmission signal (specifically, the position signal described above) of the active pen 2 corresponding to the pen position (this time pen position) determined in step S3 this time. It is compared with a predetermined threshold value, and it is determined whether or not to output the detected pen position according to the result of the comparison (step S103). Specifically, when it is determined that the level of the transmission signal is lower than the predetermined threshold value (low), the process proceeds after step S4, and the process proceeds to the touch detection step shown in FIG. On the other hand, if it is determined that the level of the transmission signal is equal to or higher than a predetermined threshold value (high), the process proceeds to step S104. Here, the threshold value used in step S103 is set to a value larger than the predetermined value used by the MCU 40 to detect the position of the active pen 2. The process of step S103 is nothing but a process of raising the threshold value for detecting the pen position after the fact, which makes it possible to reduce the possibility that the ghost position G is detected in the cross region XR. ..

Next, the sensor controller 31 calculates the distance between the previous pen position and the current pen position. In FIG. 23, this distance corresponds to the distance between the _{fixed pen positions fP n-1} and fP _n. Then, the sensor controller 31 determines whether or not this distance exceeds a predetermined value (long) or (short) (step S104). When it is determined that the value is exceeded, the pen-up information OUT-PROXY indicating that the active pen 2 has left the touch surface 3a and the pen-down information IN- indicating that the active pen 2 has touched the touch surface 3a PROXY and PROXY are sequentially output to the host processor 32 (steps S105 and S106). When it is determined in step S104 that the pen position is not exceeded, and after step S106 is completed, the sensor controller 31 stores the determined pen position separately from the pen position table described above (step S107), and then steps S4. Output processing of.

As described above, according to the pointer position detection process according to the present embodiment, when the distance between the pen position detected this time and the pen position detected last time exceeds a predetermined value, the pen-up information OUT -PROXY can be output to the host processor 32. Therefore, since the host processor 32 determines that the pen position this time and the pen position last time belong to different strokes, an unnecessary line segment such as the line segment L shown in FIG. 23 is drawn due to the presence of the ghost position G. It is prevented from being done.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and the present invention can be implemented in various embodiments without departing from the gist thereof. Of course.

For example, the pointer position detection process according to the present embodiment can be suitably carried out in an embodiment other than those described above. Hereinafter, a specific example will be described.

FIG. 21A is a diagram showing a control sequence related to the position detection process according to the first modification of the present embodiment. The MCU 40 according to this modification is doubled by performing 1/2 processing at a predetermined interval and synthesizing the partial detection data obtained in each processing and the partial detection data obtained in the immediately preceding processing. It is configured to generate the whole detection data FM1, FM2, FM3, FM4 ... At the detection rate of. In the interval, the position detection process or the pixel drive operation of the active pen 2 may be executed, or the position detection process and the pixel drive operation of the active pen 2 may be executed in a time division.

In connection with the first modification, the MCU 40 determines whether or not to execute the position detection process of the finger 4 at the predetermined interval, and only when it is determined to execute the position detection process of the finger 4, the position detection process of the finger 4 is performed by N. It may be executed in batches. If it is determined not to be executed, steps S5 to S7 shown in FIG. 3 are replaced by steps S103 shown in FIG. By doing so, it becomes possible to change the execution method of the position detection process of the finger 4 depending on whether or not it is necessary to perform the position detection process or the pixel drive operation of the active pen 2.

FIG. 21B is a diagram showing a control sequence related to the position detection process according to the second modification of the present embodiment. The MCU 40 according to this modification is configured to perform the position detection process of the finger 4 in two steps, even though the position detection process of the finger 4 is continuously performed (without intervals). As a result, as shown in the figure, the entire detection data FM1, FM2, FM3, FM4 ... Are generated at a detection rate twice as high as that in the case where the position detection process of the finger 4 is performed by one process. It will be possible to do.

FIG. 21C is a diagram showing a control sequence related to the position detection process according to the third modification of the present embodiment. The MCU 40 according to this modification is configured to perform the position detection process of the finger 4 in three steps, even though the position detection process of the finger 4 is continuously performed (without intervals). As a result, as shown in the figure, the entire detection data FM1, FM2, FM3, FM4 ... Are generated at a detection rate three times higher than that in the case where the position detection process of the finger 4 is performed by one process. It will be possible to do.

In addition, in the above embodiment, an example in which the position detection process of the finger 4 (passive pointer) is divided into a plurality of times has been described, but the position detection process of the active pen 2 is also divided into a plurality of times in the same manner. You may do it.

Further, in the above embodiment, the MCU 40 has been described as always performing the output position determination process using the pen position table and the touch position table, but for example, only one position is detected in step S21 of FIG. If so, the position may be determined as the pen position to be output, and the pen position determination process in step S3 may be skipped. Similarly, when only one position is detected in step S51 of FIG. 9, that position is determined as the passive pointer position to be output, and the passive pointer position determination process of step S8 is skipped. May be good.

Further, in the above embodiment, the logic unit 41 and MCU40, when sending the finger detecting signal FDS, selects one of the sensor electrodes 30Y, the pulse group _p 1 ~p _K described above to the transmitting unit 42 It is assumed that the operation of sequentially inputting to each sensor electrode 30X is repeated for each sensor electrode 30Y, but a receiving unit 44 is provided for each sensor electrode 30Y, and processing for each sensor electrode 30Y is executed in parallel. May be good. In this case, in the second and fourth examples of the contents of the 1 / N processing shown in FIGS. 15 and 17, the effect of shortening the position detection processing time cannot be obtained, but on the other hand, 2 Since one receiving unit 44 can be shared by the sensor electrodes 30Y of the book, a new effect of reducing the circuit scale of the receiving unit 44 can be obtained as compared with the case where the receiving unit 44 is provided for each sensor electrode 30Y. Will be possible.

1 Position detection system 2 Active pen 3 Tablet 3a Touch surface 3b Bezel area 4 Finger 5 Hand 30 Sensor 30X, 30Y Sensor electrode 31 Sensor controller 32 Host processor 40a Shift register 40b Correlator 41 Logic unit 42, 43 Transmitter 44 Receiver 45 Selection unit 50 Pattern supply unit 51 Switch 52 Code string holding unit 53 Diffusion processing unit 54 Transmission guard unit 55 Amplification circuit 56 Detection circuit 57 Analog digital converter 58x, 58y Switch 59x, 59y Conductor selection circuit COM command CR Current path DS Downlink signal FDS finger detection signal _L 9 ~L _K levels Res data SB start bit _T 1 through T ₄ correlation US uplink signal Vcom pixel-driving voltages cP [i] candidate pen position cT [j] candidate touch position ctrl_t1~ctrl_t4 , Ctrl_r Control signal fP [i] Confirmed pen position fT [j] Confirmed touch position G Ghost position P Pen position Palm Palm area p _{1 to p K} pulse group s _{1 to s K} signal XR Cross area

Claims (4)

Performed by a sensor controller connected to the sensor pattern,
The position of the passive pointer that does not send a signal, and
It is a method of detecting the position of a pointer that detects the position of an active pen configured to be able to transmit a signal from a pen electrode provided at the tip.
It comprises a pen detection step of detecting a pen signal transmitted through the pen electrode and detecting a pen position which is the position of the active pen based on the detected level of the pen signal.
The pen detection step is
When the distance between the pen position detected this time and the pen position detected last time exceeds a predetermined value, the pen-up information indicating that the active pen has moved away from the touch surface is output, and then the detection is performed this time. Output the pen position
When the distance between the pen position detected this time and the pen position detected last time does not exceed the predetermined value, the pen position detected this time is output without outputting the pen-up information.
How to detect the position of the pointer. The pen detection step provides pen-down information indicating that the active pen has touched the touch surface when the distance between the pen position detected this time and the pen position detected last time exceeds a predetermined value. After outputting the pen-up information, the pen position detected this time is output.
The pointer position detection method according to claim 1. A touch detection step of detecting the position of the passive pointer by detecting a change in capacitance in the sensor pattern and determining whether the area type of the detected position of the passive pointer is palm or finger. Including more
In the pen detection step, when the position of the passive pointer whose area type is determined to be palm is detected by the touch detection step, the pen position detected this time and the pen position detected last time are used. Determining whether the distance between them exceeds the predetermined value,
The pointer position detection method according to claim 1 or 2. The pen detection step is
When the detected level of the pen signal is equal to or higher than a predetermined value, the pen position is detected.
The level of the transmission signal of the active pen corresponding to the pen position detected this time is compared with a predetermined threshold value larger than the predetermined value, and when the level is lower than the predetermined threshold value, the output of the pen position detected this time is output. Do not do,
The pointer position detection method according to any one of claims 1 to 3.

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