KR102034052B1 - Touch input system and method for detecting touch using the same - Google Patents

Abstract

The present invention relates to a touch input system and a touch detection method using the same that allow a battery-free stylus pen and a touch by a finger to be distinguished and detected, and further improve the touch sensitivity and accuracy. A touch sensor panel having a second channel; A stylus pen including a primary coil and a secondary coil separated from each other, a resonant capacitor and a switch connected in series with the secondary coil, and a conductive tip connected to the primary coil; A ground part connected to the stylus pen; An antenna loop formed of a plurality of loop structures formed outside the sensor panel; And a touch controller connected to the first channel and the second channel and the antenna loop.

Description

TOUCH INPUT SYSTEM AND METHOD FOR DETECTING TOUCH USING THE SAME}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a touch input system, and more particularly, to a touch input system and a touch detection method using the same without a battery-free stylus pen and a finger touch so that the touch detection and classification can be further improved. will be.

In recent years, as the information age has entered, the display field for visually expressing electrical information signals has been rapidly developed. Accordingly, various flat panel displays having excellent performance of thinning, light weight, and low power consumption have been developed. Display Device) is being developed.

The flat panel display includes a liquid crystal display device, a plasma display panel device, a field emission display device (FED), and an organic light emitting diode display device. ), And the like.

Recently, a touch panel capable of recognizing a touch portion through a hand of a person or a separate input means and transmitting separate information in response thereto is increasing. Currently, such a touch panel is applied in the form of attaching to an outer surface of the display device. In addition, according to the touch sensing method, it is divided into a resistive method, a capacitive method, an infrared sensing prevention, etc., and the capacitive method has recently attracted attention in view of the convenience and detection power of the manufacturing method.

Recently, as a mobile device that is mainly considered, smart phones, smart books, etc., as a HID (Human Interface Device), as well as a touch input using a finger, a stylus pen capable of writing or drawing using a pen is increasingly applied as an input device. to be. The stylus pen input has more advantages than the input by the finger, and has the advantage of supporting functions such as detailed drawing and writing.

However, in the case of the touch panel to which the same touch detection circuit is applied, the stylus pen touch sensitivity is inferior and there is a problem in that the touch by the finger and the touch by the stylus pen cannot be distinguished. In other words, in the case of a general touch panel to which the same touch detection circuit is applied, it is difficult to detect a change in capacitance because the contact area with the touch panel is small when the stylus pen is touched. As a result, the accuracy of coordinate extraction is lowered, and it is difficult to have a function of palm rejection. Therefore, a method of detecting touch using a stylus pen through a driving method different from the touch sensor panel touch, for example, an electromagnetic driving method, has been introduced. In this case, in addition to the separate capacitive electrode, Since the panel should be further provided, it is possible to increase the number of components and process.

The present invention is to solve the above problems, the touch input system and the touch detection method using the same to further improve the touch sensitivity and accuracy while being able to detect and detect the touch by the finger and the battery-free stylus pen It is about.

According to an aspect of the present invention, there is provided a touch input system including: a touch sensor panel having a plurality of first and second channels crossing each other; A stylus pen including a primary coil and a secondary coil separated from each other, a resonant capacitor and a switch connected in series with the secondary coil, and a conductive tip connected to the primary coil; A ground part connected to the stylus pen; An antenna loop formed of a plurality of loop structures formed outside the sensor panel; And a touch controller connected to the first channel and the second channel and the antenna loop.

The antenna loop of the multi-loop structure may receive a resonant inductance signal from a primary coil in the stylus when the stylus pen touches the surface of the touch sensor panel.

The antenna loop of the multi-loop structure is formed so as to surround the front outer periphery of the touch sensor panel, and pads are provided at both ends of one side and the other side to be connected to the touch controller.

The antenna loop of the multi-loop structure may transmit an inductance signal resonated from a secondary coil in the stylus pen when the touch sensor panel of the stylus pen touches the mutual inductance between the antenna loop itself and the secondary coil or the antenna loop itself and the antenna loop itself. Characterized in that it receives by inducting mutual inductance between the primary coils.

The touch controller is connected to the antenna loop, an amplifier for amplifying the received voltage difference across the antenna loop; A filter unit connected to the amplifier to remove noise; A converter connected to the filter unit to convert an analog signal into a digital signal; A signal processor connected to the converter to collect digital signals and extract coordinates; And a driving signal generator for generating a signal applied to each channel in the sensor panel.

In addition, the touch detection method using a touch input system according to an embodiment of the present invention for achieving the above object is a sensor panel having a plurality of first and second channels that cross each other, and the primary coil divided And a stylus pen including a secondary coil, a resonant capacitor and a switch connected in series with the secondary coil, a conductive tip connected to one end of the primary coil, and an antenna loop formed in a plurality of loop structures outside the sensor panel. In the touch detection method of the input system, it is characterized by time division between finger touch detection and stylus pen touch detection for each frame.

The stylus pen touch detection may be performed by sequentially applying signals to the plurality of first and second channels, and performing touch detection based on a voltage difference received at both ends of the antenna loop of the plurality of loop structures. .

The antenna loop of the multi-loop structure is formed so as to surround the front outer periphery of the touch sensor panel, and pads are provided at both ends of one side and the other side to be connected to the touch controller.

The touch detection is an electrical connection between the detection capacitor and the primary coil between the conductive tip and the sensor panel, the switch is closed to form a resonant circuit of the secondary coil and the resonant capacitor, and the primary coil Characterized in that the induced electromotive force is electromagnetically resonated to the antenna loop of the multi-loop structure by the mutual inductance between the secondary coils.

The touch detection by the touch controller may include sequentially detecting a voltage difference received at both ends of the antenna loop of the plurality of loop structures for the plurality of first and second channels; Amplifying the voltage difference; Removing noise of the amplified voltage difference; Converting the noise-amplified amplified voltage difference from an analog signal to a digital signal; And storing the digital signal in a memory, and detecting touch coordinates by calculating the digital signals stored in the plurality of first and second channel-specific memories.

The touch input system and the touch detection method using the same of the present invention as described above have the following effects.

First, as a basic configuration, a capacitive touch detection method is used for finger touch, and when the touch of the stylus pen is detected, touch detection by resonance is possible through an internal resonant circuit inside the stylus pen and an antenna loop outside the sensor panel. Do. In other words, the capacitive touch detection of the stylus pen touch detection, which has a limit in touch detection, is possible without changing the panel and the sensor panel outer configuration and the stylus pen internal circuit without affecting the contact area or the shape of the electrode pattern. Let's do it.

Second, touch detection is possible due to the resonance action between the antenna loop of the sensor panel formed of a plurality of loop structures and the resonance circuit inside the stylus pen, so that the battery does not need to be mounted inside the stylus pen, and thus requires a separate power source. The manufacturing cost is reduced compared to the stylus pen. It is also possible to implement a light and small stylus pen.

Third, the stylus pen touch and the finger touch can be detected separately by different driving methods, so that palm rejection is facilitated in the case of the stylus pen touch, and the antenna of the sensor panel formed of a plurality of loop structures The loop improves the accuracy of the touch sensitivity.

Fourth, by placing the antenna loop formed of a plurality of loop structures used for touch detection by the stylus pen outward from the edge region where the sensitivity is spaced apart from the active region where the electrodes cross each other, the sensitivity of the stylus pen is related to the region. Can be kept equal without.

1 is a circuit diagram illustrating a touch input system according to an exemplary embodiment of the present invention.
FIG. 2 is a plan view illustrating the touch sensor panel illustrated in FIG. 1.
3 is a circuit diagram illustrating a portion corresponding to the stylus pen of FIG. 1.
4 is a structural diagram of the stylus pen of FIG.
5 is a view showing a frame driving method of the touch input system of the present invention.
6 is a waveform diagram showing detection waveforms of respective components of a touch sensor panel and a stylus pen;
FIG. 7 is another plan view showing in detail the antenna loop of the multi-loop structure shown in FIG.
8A to 8C are waveform diagrams illustrating input / output waveforms input / output to loop pads according to the number of loops of an antenna loop according to the present invention.

Hereinafter, a touch input system and a touch detection method using the same will be described in detail with reference to the accompanying drawings.

The touch input system of the present invention uses a structure of capacitive touch detection for a finger touch as a basic configuration, and the touch detection of a battery-free stylus pen uses an internal resonance circuit of the stylus pen and an antenna loop outside the touch sensor panel. Touch detection by resonance is possible. That is, stylus pen touch detection, which is limited in touch detection by capacitive type, does not form a separate panel, but changes the contact area by changing an antenna loop configuration and an internal circuit of the stylus pen outside the touch sensor panel formed of a plurality of loop structures. This is possible without being affected by the shape of the electrode pattern.

1 is a circuit diagram illustrating a touch input system according to an exemplary embodiment of the present invention. 2 is a plan view illustrating the touch sensor panel illustrated in FIG. 1.

The touch input system illustrated in FIG. 1 includes a touch sensor panel including a stylus pen 100, a touch sensor 200, and an antenna 400 having a loop structure, a touch controller 300, and a stylus ground part 500. .

1 and 2, the touch sensor panel 201 is largely divided into an active area and an outer area thereof. The touch sensor 200 has a plurality of first channels Tx and a second channel Rx that cross each other and is positioned in an active area corresponding to the center of the touch sensor panel. In addition, an antenna loop 410 is formed on the outer edge of the active area of the touch sensor panel in a shape surrounding the outer edge of the active area, that is, a plurality of loops spaced apart from both ends, thereby performing the function of the antenna 400.

The plurality of first channels (Tx) 210 and the second channels (Rx) 220 formed in the active region have a bar shape, respectively, and the first channel (Tx) 210 and the second channel (Rx) ( 220, the channels cross each other and are disposed in the active region. The first channel (Tx) 210 and the second channel (Rx) 220 is preferably formed of a transparent electrode for light transmission in the display device. In addition, the first channel (Tx) 210 is used for driving signals and the second channel (Rx) 220 is used for receiving a detection signal in a finger touch section, and one edge of each of the touch sensor panels 201 is used. It is electrically connected to the pad 230 provided in the through the routing line 225. The shape shown in FIG. 2 is a bar-shaped channel, and in some cases, may be changed to a pattern of another type of capacitive type. For example, it may be a diamond pattern or other polygonal shape. In any case, in the input system of the present invention, it is required to be formed in a form having symmetry in the center, up, down, left and right for accuracy of the stylus pen touch.

The antenna loops 410 may be formed so as not to overlap each other in a plurality of loops in order to receive electromagnetic signals generated from the resonant circuit in the stylus pen 100. The antenna loop 410 is a kind of tertiary coil capable of inductance induction, and does not include a magnetic core having a separate physical shape. Loop pads 240 formed in parallel with the plurality of pads 230 provided at one edge of the touch sensor panel 201 are formed at both ends of the antenna loop 410 having a plurality of loops, and the voltage difference between the two loops is formed. It can be detected by the touch controller. Here, the pads 204 electrically connected to both ends of the antenna loop 410 are electrically connected to the touch controller 300.

3 is a circuit diagram illustrating a part corresponding to the stylus pen of FIG. 1. 4 is a diagram illustrating the stylus pen of FIG. 3 structurally.

In the stylus pen 200 illustrated in FIGS. 3 and 4, the primary coil L1 and the secondary coil L2 120, which are separated from each other, are connected to the secondary coil 120 in series. Capacitor C2 110 and switch SW 130 and a conductive tip 101 connected to the primary coil 140 are included.

The stylus pen 100 is connected to the stylus ground portion 500 to stabilize the internal circuit of the stylus pen.

The antenna loop 410, the first channel Tx, and the second channel Rx, each of which has a plurality of loops formed outside the touch sensor panel 201, are connected to the touch controller 500 to receive signal control.

In addition, the antenna loop 410 having a plurality of loops forms an inductance signal resonated from the secondary coil (L2) 120 in the stylus pen 100 when the touch sensor panel 201 of the stylus pen 100 is touched. In operation 410, the inductance M23 between the L3 and the secondary coil L2 or the mutual inductance M13 between the antenna loop 410 and the primary coil L1 may be received.

The touch controller 300 is an amplifier 310 that amplifies the voltage difference received across the antenna loop 410, a filter unit (AFE) 320 connected to the amplifier 310 to remove noise, and a filter unit 320. A converter (ADC) 330 connected with the converter to convert an analog signal into a digital signal, a signal processor (DSP) 340 connected with the converter 330 to extract coordinates by collecting a digital signal, and a touch sensor panel 201. It includes a drive signal generator (305) for generating a signal applied to each channel in the.

Here, when the stylus pen 100 touches the touch sensor panel 201, the internal switch (SW) 130 of the stylus pen 100 is closed, and the secondary coil L2 120 and the resonant capacitor C2 are closed. 110 forms a closed circuit as a kind of resonant circuit.

The signal applied to each channel by the drive signal generator 305 is a square wave or a sine wave at the same frequency as the resonance frequency f = 1 / [2π * (L2 * C2) ^ 0.5] in the closed loop. (sine wave) can be applied. The signal applied to each channel is a kind of alternating voltage, and each coil has a signal shape in the form of a waveform similar to the applied signal or a waveform that grows with time.

Meanwhile, the stylus grounding part 500 may be a user connected to the stylus pen 100 or a wire connected between the stylus pen 100 and the touch sensor panel 201. Ch 510 indicates that when the user comes into contact with the stylus pen 100, the user functions as a dielectric to generate a ground capacitance Ch between the stylus pen 100 and the ground terminal.

The primary coil (L1) 140 and the secondary coil (L2) 120 inside the stylus pen each have a first mutual inductance (mutual inductance) through a magnetic core passing through a central axis inside the stylus pen 100 ( M12).

Meanwhile, the secondary coil (L2) 120 and the resonant capacitor (C2) 110 are capacitive from the touch sensor 200 formed by the crossed first and second channels Tx / Rx of the touch sensor panel. It is configured to have an appropriate value to generate the frequency and the electromagnetic resonance of the signal input through the coupling formed detection capacitor (Csx) 250. Here, the resonance frequency has a condition of f = 1 / [2π * (L2 * C2) ^ 0.5]). In addition, the detection capacitor (Csx) 250 is not a device having a physical circuit configuration, but a virtual generated by the capacitive coupling at the contact portion when the conductive tip of the stylus pen 100 contacts the sensor panel 201. It is an element of.

In addition, the magnetic field signal generated during the electromagnetic resonance in the stylus pen 100 is an antenna loop (L3) 410 formed in the primary coil (L1) 140 or the secondary coil (L2) 120 and the touch sensor panel 201. Induced electromotive force is generated in the tertiary coil (L3) 410 corresponding to the antenna coil by the second mutual inductance (M13 or M23). The induced electromotive force is amplified by an amplifier 310 capable of amplifying a voltage difference between the both ends of the antenna loop 410, and a filter unit (AFE: Anaolog Front End) 320 formed of a filter for removing noise or the like. After coarse, the signal is converted into a digital signal by an ADC (Analog to Digital Converter) 330 and extracted by a suitable algorithm in the Digital Signal Processor (DSP) 340. Will be sent.

On the other hand, one end of the primary coil (L1) 140 in the stylus pen 100 is connected by a stylus tip, the other end is connected to the conductive body portion made of a conductive material of the stylus and grounded. In some cases, when the user configures the ground part 500, the user may be connected to the ground part capacitor Ch corresponding to the human body.

Referring to FIG. 4, the stylus pen 100 has a shape in which the primary coils L1 and 140 and the secondary coils L2 120 are alternately wound around a magnetic core 135. Is placed.

The primary coil (L1) 140 and the secondary coil (L2) 120 inside the stylus pen 100 are wound around a magnetic core 135 positioned in the axial direction of the stylus pen 100. . In this case, the axial direction corresponds to the longitudinal direction of the pen and corresponds to the Z axis of the X, Y, Z coordinate system.

The conductive body 150 of the stylus pen 100 includes a primary coil (L1) 140 and a secondary coil (L2) 120, a resonant capacitor (C2) 110, and a magnetic core 135 therein. It may include, and the conductive tip 101 may have a hole that partially protrudes. In this case, the conductive tip 101 is insulated from the conductive body 150, and for this purpose, the conductive tip 101 may further include an insulating buffer part (not shown) surrounding the conductive tip 101. The conductive body 150 is preferably connected to the stylus ground portion 500 described above.

On the other hand, the switch (SW) 130 may be made of a spring (spring) or elastic rubber (elastic rubber), the first insulating film between the conductive tip 101 to maintain insulation with the conductive tip 101 103 may be provided. In addition, the switch 130 is operated by the pressure applied when the conductive tip 101 presses the touch sensor panel. That is, when pressed above a certain pressure, the switch 130 is closed to form a closed circuit of the internal resonant circuit.

In addition, the switch SW 130 may be connected to the secondary coil L2 120 and may be insulated from the magnetic core 135 through the second insulating layer 107.

One end of the primary coil (L1) 140 is connected to the conductive tip 101, the other end is connected to the ground terminal 125 of the conductive body 150.

Looking at the operation of the stylus pen shown in Figures 3 and 4 as follows.

One end of the primary coil (L1) 140 is capacitively coupled with the touch sensor (see 200 in FIG. 6) of the touch sensor panel through the conductive tip 101 to form a detection capacitor (Csx) 250. Thus, the input signal from each channel of the touch sensor drives the primary coil (L1) 140 via Csx, which is the secondary coil (L2) 120 through the magnetically coupled first mutual inductance (M12). And a resonant capacitor (C2) 110.

The signal input from the driving signal generator 305 to each channel Tx and Rx of the touch sensor 200 and the electromagnetic of the resonant circuit including the secondary coil L2 120 and the resonant capacitor C2 110. The circuit is configured so that the resonant frequencies are the same, in which case the signal strength increases with time due to electromagnetic resonance. At this time, the other end of the primary coil (L1) 140 is grounded through a ground portion capacitor (Ch) consisting of the body of the hand and the person in contact with the conductive body 150 of the stylus pen.

The switch (SW) 130 allows electromagnetic resonance to occur only when the conductive tip 101 is pressed and closed to some extent on the touch sensor panel surface, thereby enabling input detection of the stylus pen. That is, even if the stylus pen is close to the touch sensor panel, it does not operate unless it is pressed to some extent, thereby preventing a malfunction. The magnetic field signal generated during the electromagnetic resonance is transmitted to the antenna loop 410 in the form of a plurality of loops located at the outer side of the touch sensor panel, and functions as a kind of tertiary coil (L3) 410 to touch the voltage difference across the touch controller. Detected by 300.

As described above, when the stylus pen 100 touches the touch sensor panel 201, generation of the detection capacitor Csx 250 and grounding through the body of the stylus are possible. In this case, a signal applied to the detection capacitor Csx 250 is transmitted to the primary coil L1 through the conductive tip in the stylus pen 100.

Subsequently, the signal transmitted to the primary coil L1 is transmitted to the secondary coil L2 by the first mutual inductance M12. The secondary coil L2 and the resonant capacitor C2 are closed by a closed circuit formed by closing the switch SW, and are resonated. As time passes, the magnitude of the signal of the secondary coil L2 increases. In this case, the adjacent primary coil L1 may also be affected by the signal of the secondary coil L2 raised by the first mutual inductance M12.

In addition, the magnetic field signal of the secondary coil L2 in the resonant circuit is guided to the antenna loop by the second mutual inductance M23.

Detection in such an antenna loop proceeds every channel. This is because the frequency causes electromagnetic resonance and the amplitude increases with time.

In addition, when the stylus pen 100 touches the touch sensor panel, the primary coil L1 or the secondary coil L2 is coupled to the antenna loop in the touch sensor panel through the second mutual inductance M23. The antenna loop may detect an electromagnetic signal generated by the resonance of the stylus pen.

On the other hand, in the antenna loop of the multi-loop structure, detecting the voltage difference received at both ends of the antenna loop, amplifying the voltage difference, removing noise of the amplified voltage difference, amplified voltage difference from which the noise is removed By converting an analog signal into a digital signal and storing the digital signal in a memory, the signal strength digital data for the voltage difference between the two ends of the antenna loop corresponding to the corresponding channel is stored.

5 is a diagram illustrating a frame driving method of the touch input system according to the present invention. 6 is a waveform diagram illustrating detection waveforms of respective components of the touch sensor panel and the stylus pen.

5 and 6, the input system of the present invention divides one frame into stylus touch detection and finger touch detection to time-division drive. The stylus touch detection and the finger touch detection are alternately made.

For example, when one frame corresponds to 5-10 ms, the frame rate corresponds to 100 to 200 Hz. In this case, when dividing one frame into stylus touch detection and finger touch detection, each allocation section corresponds to 2.5ms to 5ms. This is when dividing the stylus touch detection and the finger touch detection into two, and in some cases, it may be possible to adjust either time longer within one frame.

On the other hand, when stylus touch detection, when the number of the first channel (Tx) and the second channel (Rx) is m and n, respectively, m channels Tx (1) to Tx (m) and the first channel of the first channel N channels Rx (1) to Rx (n) of two channels are sequentially driven and detected. That is, the total 'm + n' channels are sequentially driven in the stylus touch detection section. Thus, for example, assuming 'm + n' = 50, the time required to drive one channel is 50 ms to 100 ms divided by 50 divided by 2.5 ms to 5 ms.

In the case of finger touch detection, a driving signal is sequentially applied to the first channel Tx, a detection signal is detected on the second channel Rx, and a change according to a touch is detected to detect a touch position. . In the case of finger touch detection, the driving signal is applied only to the first channel Tx. Therefore, the angle of finger touch detection is greater than the signal application time (2.5 ms to 5 ms / (m + n)) of each channel at the time of stylus touch detection. The driving signal application time (2.5 ms to 5 ms / m) of the first channel Tx may be long.

In this case, the signal waveform and the detection waveform for driving each channel alternately drive the stylus input and the finger touch in time division as will be described later.

Next, a method of driving and detecting each channel in stylus pen touch detection will be described with reference to FIG. 6, but the process of driving a channel of Tx (n) is performed in the same manner as Tx (0) to Tx ( 5), signals may be sequentially applied in the order of Rx (0) to Rx (5), and touch detection may be performed by a voltage difference received at both ends of the antenna loop 410 for each channel.

In the touch detection, an electrical connection is formed between the detection capacitor Csx and the primary coil L1 between the conductive tip and the touch sensor panel 201, and the switch SW is closed to close the secondary coil L2 and the resonant capacitor ( A resonance circuit of C2 is formed, and electromagnetic resonance is induced to the antenna loop 410 by the secondary coil L2 or the primary coil L1 and the second mutual inductance M23 between the antenna loops. Is done.

Signals applied to the plurality of channels Tx (0) to Tx (5) and Rx (0) to Rx (5) may be square waves or sinusoidal files having the same frequency as the resonance frequency in the resonance circuit.

The stylus pen 100 may be grounded by the user when the stylus pen 100 is touched on the surface of the touch sensor panel 201. Here, when grounding, the user directly contacts the conductive body or connects the conductive body through a touch sensor panel and a wire.

When driving the Tx (5) channel of FIG. 6, a T1 time is applied to the Tx (5) channel by a square wave or a sine wave of a predetermined frequency from the touch controller. In addition, without applying a signal to the Tx (5) channel for the time T2, only the signal received in the circuit and the antenna loop can be detected. That is, when a square wave or sinusoidal signal is applied to the Tx (5) channel, during this time, the primary coil L1 of the stylus pen will detect the detection capacitor Csx generated by the capacitive coupling between the Tx channel and the conductive tip. When the stylus pen is touched on the surface of the touch sensor panel, an electrical connection is formed between the detection capacitor Csx and the conductive tip, thereby generating a weak waveform in synchronization with the square wave in the primary coil. This is again coupled between the primary coil and the secondary coil to form a first mutual inductance M12 through which the secondary coil is driven. In this case, the secondary coil has a larger waveform as time passes in the T1 time, since the secondary coil generates an electromagnetic resonance through the resonance frequency and the resonance capacitor C2 connected in series in the resonance circuit of the closed circuit, and the amplitude increases with time. .

In addition, when the stylus pen 100 touches the touch sensor panel, the primary coil L1 or the secondary coil L2 is coupled to the antenna loop in the touch sensor panel through the second mutual inductance M23. The loop may detect an electromagnetic signal generated by the resonance of the stylus pen.

Through this process, when the signal strength digital data for each channel of one frame is collected, the coordinates of the position where the stylus pen is located through the signal processor of the touch controller are extracted.

On the other hand, as shown in the signal application section of the stylus pen, only T1 may be applied to provide a subsequent detection section sufficiently, or a signal application and detection may be simultaneously performed in the T1 + T2 section. There are advantages and disadvantages, and if the signal reception interval is T1 + T2, it is possible to expect an increase in the accuracy of the measured signal as the time for receiving the signal becomes longer. However, during the T1 time, the Tx or Rx channels are driven and parasitic loops consisting of these channels can cause magnetic field signals, which become noise components in the antenna loop, which together with the signals generated in the resonant circuit inside the stylus pen It may be received to the antenna loop side.

Therefore, in the case where it is difficult to accurately detect the magnetic field interference caused by the parasitic loop, the touch detection may be performed by detecting the resonance signal of the stylus pen only in the T2 section. In this case, since the resonance signal is not received during the T1 time, the signal reception time and the data precision may be reduced, but there is an advantage that the magnetic field noise does not affect the antenna loop.

FIG. 7 is another plan view illustrating the antenna loop of the multi-loop structure illustrated in FIG. 2 in detail.

An antenna loop 410 is formed on the outer portion of the active area of the touch sensor panel 201 illustrated in FIG. 7, that is, in the form of a plurality of loops spaced apart from each other. Perform the function.

The antenna loop 410 in the form of a plurality of loops is formed to surround the active area in the outer area of the touch sensor panel 201 to receive electromagnetic signals generated from the resonant circuit in the stylus pen 100. In particular, the antenna loop 410 may be formed not to overlap each other in a loop form of three or more times as shown in FIG. 7, rather than a two-loop form as shown in FIG. 2. Since the reception sensitivity of the electromagnetic signal is proportional to the number of loops, as the number of greens increases, the reception sensitivity of the electromagnetic signal is also improved. Therefore, the antenna loop 410 of the multi-loop structure can improve the reception sensitivity of the electromagnetic signal without changing its cross-sectional area. The antenna loop 410 of the multi-loop structure is a kind of tertiary coil capable of inductance induction, and does not include a magnetic core having a separate physical shape. Here, the plurality of antenna loops 410 may be coils that operate through an air core between stylus pens.

The antenna loop 410 of the multi-loop structure is formed as large as possible than the active touch area where the stylus input is actually performed and the coordinate extraction is performed. In the touch detection using the stylus pen 100, the edge part of the touch sensor panel 201 is to be solved at the edge of the touch sensor panel 201 due to the asymmetry of the channel.

At each end of one side and the other side of the antenna loop 410 of the multiple loop structure, a loop pad 240 formed in parallel with the plurality of pads 230 provided at one edge of the touch sensor panel 201 is formed, The voltage difference can be detected by the touch controller. Here, the pads 204 electrically connected to one side and the other end of the antenna loop 410 are electrically connected to the touch controller 300. The antenna loop 410 transmits an inductance signal resonant from the secondary coil L1 in the stylus pen 100 when the touch sensor panel 201 of the stylus pen 100 is touched with the antenna loop 410 (L3). The inductance M23 between the difference coils L2 or the mutual inductance M13 between the antenna loops 410 and L3 and the primary coil L1 may be received.

8A to 8C are waveform diagrams illustrating input / output waveforms input / output to the loop pads according to the number of loops of the antenna loop according to the present invention.

As shown in FIG. 8A, a voltage of 5 V with a 500 kHz frequency waveform may be supplied to one loop pad of the antenna loop 410 through a driving signal generator 305 in a 500 kHz frequency waveform.

When the antenna loop 410 is configured as a one-time loop structure (N = 1), the detection signal detected at the other loop pad of the antenna loop 410 is detected as a waveform of about 7.89 mV.

However, when the antenna loop 410 has a double loop structure (N = 2), a detection signal detected at the other loop pad of the antenna loop 410 is detected with a waveform having a size of about 15.78 mV. It is possible to detect a detection signal having a size that is more than twice as large as that of the antenna loop structure composed of (N = 1).

As described above, the touch input system and the touch detection method using the same according to the present invention can detect the stylus pen 100 touch and the finger touch separately from each other by different driving methods, so that the palm rejection in the case of the stylus pen touch (palm rejection) is facilitated, and in particular, the touch sensitivity and its accuracy are improved by the antenna loop 410 of the touch sensor panel 201 formed of a plurality of loop structures.

On the other hand, the present invention described above is not limited to the above-described embodiment and the accompanying drawings, it is possible that various substitutions, modifications and changes within the scope without departing from the technical spirit of the present invention It will be apparent to those of ordinary skill in the art.

100: stylus pen 101: conductive tip
103 and 107: insulating film 110: resonant capacitor
120: secondary coil 130: switch
140: primary coil 200: touch sensor
201: touch sensor panel 250: detection capacitor
300: touch controller 305: driving signal generator
310: amplifier 320: filter unit
330: converter 340: signal processing unit
400: antenna 410: antenna loop

Claims (14)

A touch sensor panel having a plurality of first and second channels and antenna loops crossing each other;
A stylus pen including a primary coil and a secondary coil separated from each other, a resonant circuit including a resonance capacitor and a switch connected in series with the secondary coil, and a conductive tip connected to the primary coil; And
And a touch controller connected to the first channel and the second channel and the antenna loop.
The resonant circuit of the stylus pen electromagnetically resonates frequencies of signals input through the plurality of first and second channels, and the switch is turned on when the conductive tip of the stylus pen presses the touch sensor panel. Touch input system, characterized in that the resonant circuit to form a closed circuit. The method of claim 1,
The antenna loop of the multi-loop structure
And the conductive tip of the stylus pen receives a resonant inductance signal from a primary coil in the stylus pen when the conductive tip of the stylus pen touches the surface of the touch sensor panel. The method of claim 2,
The antenna loop of the multi-loop structure
And a pad formed at both ends of one side and the other side to be connected to the touch controller. The method of claim 1,
The antenna loop of the multi-loop structure
When the conductive tip of the stylus pen touches the touch sensor panel, an inductance signal resonated from a secondary coil in the stylus pen is mutually inductance between the antenna loop itself and the secondary coil or between the antenna loop itself and the primary coil. Touch input system, characterized in that receiving by mutual inductance induction. The method of claim 1,
The touch controller
An amplifier connected to the antenna loop to amplify the received voltage difference across the antenna loop;
A filter unit connected to the amplifier to remove noise;
A converter connected to the filter unit to convert an analog signal into a digital signal;
A signal processor connected to the converter to collect digital signals and extract coordinates; And
And a driving signal generator configured to generate a signal applied to each channel in the sensor panel. A resonant circuit including a touch sensor panel having a plurality of first and second channels and antenna loops intersecting each other, a primary coil and a secondary coil divided from each other, and a resonant capacitor and a switch connected in series with the secondary coil. In the touch detection method of the input system having a stylus pen including a conductive tip connected to one end of the primary coil,
Time-divided finger touch detection and stylus pen touch detection per frame,
The stylus pen touch detection is,
When the signal is sequentially applied to the plurality of first and second channels and the switch is turned on when the conductive tip of the stylus pen is touched on the sensor panel, the resonance circuit is closed to form the closed circuit. And causing a frequency of a signal input through two channels to electromagnetically resonate, thereby performing touch detection by a voltage difference received at both ends of the antenna loop. delete The method of claim 6,
The antenna loop has a plurality of loop structures,
And a pad formed at both ends of one side and the other side to be connected to the touch controller. The method of claim 8,
The stylus pen touch detection
When the conductive tip of the stylus pen touches the touch sensor panel, an electrical connection is formed between the detection capacitor and the primary coil between the conductive tip and the touch sensor panel,
The switch is turned on to form a resonant circuit of the secondary coil and the resonant capacitor,
And an induced electromotive force that is electromagnetically resonated by the antenna loop by mutual inductance between the primary coil and the secondary coil. The method of claim 6,
Touch detection by the stylus pen touch controller
Detecting a difference in voltage received across the antenna loop sequentially for the plurality of first and second channels;
Amplifying the voltage difference;
Removing noise of the amplified voltage difference;
Converting the noise-amplified amplified voltage difference from an analog signal to a digital signal; And
Storing the digital signal in a memory;
And detecting touch coordinates by computing digital signals stored in the plurality of first and second channels. The method of claim 1,
The stylus pen,
Conductive body,
Magnetic core disposed in the longitudinal direction of the pen inside the conductive body,
The primary coil and the secondary coil wound alternately on the magnetic core,
The resonant capacitor and the switch connected in series with the secondary coil,
And the conductive tip insulated from the conductive body and partially protruded from the conductive body and connected to one end of the primary coil. The method of claim 11,
The switch is positioned between the magnetic core and the conductive tip, is electrically insulated from the conductive tip and the magnetic core, and is turned on by the pressure applied when the conductive tip presses the touch sensor panel to cause the resonance. Touch input system, characterized in that the circuit to form a closed circuit. The method of claim 12,
The switch is a touch input system, characterized in that made of a spring or elastic material. The method of claim 11,
And the other end of the primary coil is connected to the ground terminal of the conductive body.

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