WO2011105727A2 - Transmitter-receiver of a tablet - Google Patents

Transmitter-receiver of a tablet Download PDF

Info

Publication number
WO2011105727A2
WO2011105727A2 PCT/KR2011/001143 KR2011001143W WO2011105727A2 WO 2011105727 A2 WO2011105727 A2 WO 2011105727A2 KR 2011001143 W KR2011001143 W KR 2011001143W WO 2011105727 A2 WO2011105727 A2 WO 2011105727A2
Authority
WO
WIPO (PCT)
Prior art keywords
signal
coils
receiver
transmitter
tablet
Prior art date
Application number
PCT/KR2011/001143
Other languages
French (fr)
Other versions
WO2011105727A3 (en
Inventor
Azuma Murakami
Min Ku Shin
Seong Bok Lee
Original Assignee
Csjglobal, Inc.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Csjglobal, Inc. filed Critical Csjglobal, Inc.
Publication of WO2011105727A2 publication Critical patent/WO2011105727A2/en
Publication of WO2011105727A3 publication Critical patent/WO2011105727A3/en

Links

Images

Classifications

    • GPHYSICS
    • G06COMPUTING; CALCULATING OR COUNTING
    • G06FELECTRIC DIGITAL DATA PROCESSING
    • G06F3/00Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
    • G06F3/01Input arrangements or combined input and output arrangements for interaction between user and computer
    • G06F3/03Arrangements for converting the position or the displacement of a member into a coded form
    • G06F3/033Pointing devices displaced or positioned by the user, e.g. mice, trackballs, pens or joysticks; Accessories therefor
    • G06F3/0354Pointing devices displaced or positioned by the user, e.g. mice, trackballs, pens or joysticks; Accessories therefor with detection of 2D relative movements between the device, or an operating part thereof, and a plane or surface, e.g. 2D mice, trackballs, pens or pucks
    • G06F3/03545Pens or stylus

Definitions

  • This invention relates to a transmitter-receiver of a tablet and, more particularly, to a codeless and batteryless electronic pen and a transmitter-receiver of a tablet that calculates the position of the electronic pen by transmitting and receiving energy.
  • a codeless and batteryless electronic pen (hereinafter refer to as 'electronic pen') is a device that can wirelessly transmit and receive energy to and from the transmitter-receiver of a tablet without using a battery.
  • FIG. 1 is a block diagram of a conventional transmitter-receiver of a tablet.
  • a conventional transmitter-receiver of a tablet may include: a plurality of coils 21 that are laid on the planar tablet horizontally or vertically; an excitation signal generation unit 22 for generating the excitation signal that magnetizes the coils 21; an excitation signal amplification unit 23 for amplification of the excitation signal; a channel selection switch 24 for selecting transmitting and receiving channels, i.e. coils; a transmission-reception conversion switch 25 for conversion between transmission and reception; a signal processing unit 26 for calculating the position of the electronic pen 10 by using the induced currents in the coils 21; and a switch control unit 27 for controlling the channel selection switch 24 and the transmission-reception conversion switch 25.
  • the conventional transmitter-receiver of a tablet repeats switching steps as described below for transmitting and receiving energy to and from the electronic pen 10.
  • the channel selection switch 24 connects one of the multiple coils with the transmission-reception conversion switch 25; the transmission-reception conversion switch 25 connects the excitation signal amplification unit 23 with the channel selection switch 24.
  • the transmission-reception conversion switch 25 disconnects the excitation signal amplification unit 23 and the channel selection switch 24; and connects the signal processing unit 26 with the channel selection switch 24.
  • the channel selection switch 24 connects another coil with the transmission-reception conversion switch 25; and the transmission-reception conversion switch 25 connects the excitation signal amplification unit 23 with the channel selection switch 24.
  • the objective of the invention is to provide a transmitter-receiver of a tablet that can efficiently send and receive energy to and from the electronic pen.
  • Another objective of the invention is to provide a transmitter-receiver of a tablet that can select the transmitting and receiving channels without using any switch.
  • a transmitter-receiver of a tablet of the present invention is comprised of: an excitation signal generation unit for generating excitation signal that magnetizes the coils; a signal output circuit for alternatively outputting the excitation signal and the ground signal that enables the induced current to flow through the coil; a plurality of tri-state buffers for connecting the signal output circuit with the one ends of the coils; a buffer control unit for setting the output of the tri-state buffers either to a high impedance state or an enable state; a switching unit that turns on or off the connection between the other ends of the coils and the receiving signal amplifier that amplifies the induced current in the coil; and a switch control unit for controlling the switching unit.
  • a transmitter-receiver of a tablet of the present invention may further be comprised of a capacitor that connects the other ends of the coils with the ground.
  • a transmitter-receiver of a tablet of the present invention may further be comprised of a square wave generation unit for generating square wave signals that switches the energy transfer mode with the electronic pen from a transmission mode to a reception mode or vice versa, and outputting the square wave signals to the signal output circuit.
  • the signal output circuit may further be comprised of an AND circuit that outputs logic SUM of the excitation signal inputted from the excitation signal generation unit and the square wave signal inputted from the square wave generation unit.
  • the transmitter-receiver of a tablet of the present invention has following advantages in comparison with the conventional ones.
  • One advantage of the present invention is that there is no switch on the transmission path therefore the energy can be efficiently transmitted to electronic pen.
  • Another advantage of the present invention is that there is only one switch on the receiving path therefore the induced current inside the coil can be efficiently received.
  • Yet another advantage of the present invention is that the calculation of the position of the electronic pen is rather easy due to the low noise intermixing obtained by minimizing the switching operation.
  • Yet another advantage of the present invention is that the excitation signal can be resonated, and the frequency of the excitation signal can be tuned to the natural frequency of the electronic pen thereby making transmission-reception with the electronic pen more efficient.
  • FIG. 1 is a block diagram of a conventional transmitter-receiver of a tablet
  • FIG. 2 is a block diagram of a transmitter-receiver of a tablet according to an exemplary embodiment of the present invention
  • FIG. 3 illustrates various waveforms generated by the microprocessor of the present invention for transmitting and receiving the energy and the relevant timing relations
  • FIG. 4 is a detailed block diagram of the receiving signal processing unit of the present invention.
  • FIG. 5 is an illustration describing the calculation concept of the absolute position of the electronic pen.
  • microprocessor 131 excitation signal generation unit
  • switch control unit 135 reset control unit
  • FIG. 2 is a block diagram of a transmitter-receiver of a tablet according to an exemplary embodiment of the present invention.
  • a transmitter-receiver of a tablet of the present invention can be comprised of a plurality of coils 110, a plurality of tri-state buffers 120, a signal output circuit 140, a decoder 150, a capacitor 160, a switching unit 170, and a receiving signal processing unit 180.
  • the plurality of coils 110 are individually laid on the planar tablet horizontally or vertically.
  • each output (Y) is connected with the one end of the coil.
  • a tri-state buffer is a device whose output has an enable state and a high impedance (Hi-Z) state. In an enable state, the input signal is outputted as it is; in a high impedance state, the input signal is not outputted. In other words, the coil and the tri-state buffer are electrically isolated when the output of the tri-state buffer 120 is in a high impedance state.
  • '74AC125' can be used.
  • FIG. 3 illustrates various waveforms generated by the microprocessor of the present invention for transmitting and receiving the energy and the relevant timing relations.
  • the microprocessor 130 can be comprised of an excitation signal generation unit 131, a square wave generation unit 132, a buffer control unit 133, a switch control unit 134, and a reset control unit 135.
  • the excitation signal generation unit 131 generates an excitation signal, an AC signal having a predetermined frequency as shown in FIG. 3, that magnetizes the coils, and outputs to the signal output circuit 140.
  • the square wave generation unit 132 generates square wave signals that switches the energy transfer mode with the electronic pen from a transmission mode to a reception mode or vice versa (hereinafter refer to as 'transmission-reception conversion signal': refer to in FIG. 3); and outputs to the signal output circuit 140.
  • the high-level period is the period for energy transmission to the electronic pen
  • the low-level period is the period for energy reception from the electronic pen.
  • the transmission period can be determined by the quality factor Q of the resonance circuit of the electronic pen, and has a typical value between 150 ⁇ s to 200 ⁇ s.
  • the reception period has a typical value between 100 ⁇ s to 150 ⁇ s.
  • the buffer control unit 133 alternatively enables the multiple tri-state buffers 120. In other words, the buffer control unit 133 changes the state of the buffer from enable state to high impedance state at the rising edge of the transmission-reception conversion signal, then changes the state of the next buffer from high impedance state to enable state.
  • the switch control unit 134 for controlling the switching unit 170 generates a switching control signal (refer to in FIG. 3); and outputs to the switching unit 170. As shown in FIG. 3, the switch control unit 134 starts to output a high-level signal to the switching unit 170 at the falling edge of the transmission-reception conversion signal (refer to in FIG. 3). Then, the switch control unit 134 stops outputting the high-level signal and starts outputting a low-level signal before the transmission-reception conversion signal (refer to in FIG. 3) reaches rising edge.
  • the signal output circuit 140 alternatively outputs the excitation signal and the ground signal to the multiple tri-state buffers 120.
  • the ground signal is a signal which grounds the one end of the coil 110 such that the induced current can flow through the coil 110.
  • the reference voltage of the excitation signal is 0V (i.e. the excitation signal is an alternating signal with respect to 0V)
  • the ground signal is a DC current having amplitude of 0V.
  • the signal output circuit 140 may further be comprised of an AND circuit that outputs logic SUM of the excitation signal inputted from the excitation signal generation unit 131 and the square wave signal inputted from the square wave generation unit 132.
  • the AND circuit outputs the excitation signal inputted from the excitation signal generation unit 131 as it is when the transmission-reception conversion signal inputted from the square wave generation unit 132 is at a high-level; and outputs a ground signal when the transmission-reception conversion signal is at a low-level.
  • the decoder 150 sets the buffer selected by the buffer control unit 133 to an enable state, and sets the remaining buffers to a high impedance state. As such a decoder 150, '74HC138' can be used.
  • the switching unit 170 connects the receiving signal processing unit 180 with the other end of the coil during the high-level input period from the switch control unit 134; while the switching unit 170 disconnects the receiving signal processing unit 180 from the other end of the coil, and connects the receiving signal processing unit 180 with the ground during the low-level input period from the switch control unit 134.
  • FIG. 4 is a detailed block diagram of the receiving signal processing unit of the present invention.
  • the receiving signal processing unit 180 may be comprised of a receiving signal amplifier 181, a rectifier 182, a peak holding circuit 183 and electronic pen position calculation unit 184.
  • the receiving signal amplifier 181 which can be implemented with an operational amplifier, amplifies the minute signal (refer to a in FIG. 4) being induced in the coil 110 by using a dual power supply (+5V, -5V).
  • the rectifier 182 which can be implemented with a diode, rectifies the signal (refer to b in FIG. 4) which is amplified by the receiving signal amplifier 181.
  • the peak holding circuit 183 may be comprised of two operational amplifiers, a diode, a capacitor, and a transistor; and is a circuit that outputs a peak value (i.e. holds the peak value) of the input signal inputted from the rectifier 182.
  • the two operational amplifiers use a single power supply (5V).
  • the front-end operational amplifier amplifies the signal inputted from the rectifier 182.
  • the back-end operational amplifier outputs a peak value of the signal (refer to c in FIG. 4) which is amplified by the front-end operational amplifier.
  • the transistor is a circuit element for discharging the capacitor. In other words, the transistor resets the peak value which is held by the back-end operational amplifier, through discharging of the capacitor when the reset signal is received from the microprocessor 130.
  • the electronic pen position calculation unit 184 calculates the position of the electronic pen by using the pre-stored absolute position value of the coil 110 and the voltage value of the signal inputted from the peak holding circuit 183.
  • FIG. 5 is an illustration describing the calculation concept of the absolute position of the electronic pen.
  • the electronic pen position calculation unit 184 determines the relative position of the electronic pen (x0) by comparing the voltages induced in each coil being inputted from the peak holding circuit 183. Then the absolute position value of the electronic pen is calculated by using the absolute position values of the individual coils.
  • the transmitter-receiver of a tablet of the present invention is not limited by the above-described exemplary embodiments, and various changes and modification may be made thereto, without departing from the scope and spirit of the present invention.

Abstract

This invention relates to a codeless and batteryless electronic pen and a transmitter-receiver of a tablet that calculates the position of the electronic pen by transmitting and receiving energy. A transmitter-receiver of a tablet comprises: an excitation signal generation unit for generating excitation signal that magnetizes the coils; a signal output circuit for alternatively outputting the excitation signal and the ground signal that enables the induced current to flow through the coil; a plurality of tri-state buffers for connecting the signal output circuit with the one ends of the coils; a buffer control unit for setting the output of the tri-state buffers either to a high impedance state or an enable state; a switching unit that turns on or off the connection between the other ends of the coils and the receiving signal amplifier that amplifies the induced current in the coil; and a switch control unit for controlling the switching unit.

Description

TRANSMITTER-RECEIVER OF A TABLET
This invention relates to a transmitter-receiver of a tablet and, more particularly, to a codeless and batteryless electronic pen and a transmitter-receiver of a tablet that calculates the position of the electronic pen by transmitting and receiving energy. A codeless and batteryless electronic pen (hereinafter refer to as 'electronic pen') is a device that can wirelessly transmit and receive energy to and from the transmitter-receiver of a tablet without using a battery.
FIG. 1 is a block diagram of a conventional transmitter-receiver of a tablet.
As shown in FIG. 1, a conventional transmitter-receiver of a tablet may include: a plurality of coils 21 that are laid on the planar tablet horizontally or vertically; an excitation signal generation unit 22 for generating the excitation signal that magnetizes the coils 21; an excitation signal amplification unit 23 for amplification of the excitation signal; a channel selection switch 24 for selecting transmitting and receiving channels, i.e. coils; a transmission-reception conversion switch 25 for conversion between transmission and reception; a signal processing unit 26 for calculating the position of the electronic pen 10 by using the induced currents in the coils 21; and a switch control unit 27 for controlling the channel selection switch 24 and the transmission-reception conversion switch 25.
The conventional transmitter-receiver of a tablet repeats switching steps as described below for transmitting and receiving energy to and from the electronic pen 10.
1. The channel selection switch 24 connects one of the multiple coils with the transmission-reception conversion switch 25; the transmission-reception conversion switch 25 connects the excitation signal amplification unit 23 with the channel selection switch 24.
2. Next, after the predetermined signal-transmission period (for example, 150~200㎲) is over, the transmission-reception conversion switch 25 disconnects the excitation signal amplification unit 23 and the channel selection switch 24; and connects the signal processing unit 26 with the channel selection switch 24.
3. Next, after the predetermined signal-reception period (for example, 150~200㎲) is over, the channel selection switch 24 connects another coil with the transmission-reception conversion switch 25; and the transmission-reception conversion switch 25 connects the excitation signal amplification unit 23 with the channel selection switch 24.
However, there are several problems in the above-described switching method.
It is difficult for the electronic pen to send energy efficiently. Main reason is that there are two switches on the transmission signal path between the signal source and the coils. In order to send energy efficiently from the coil to the electronic pen, it is desirable that the impedance of the transmission path must be kept as low as possible. However, energy is consumed by the internal resistance of the switch.
Moreover, since there are two switches on the receiving signal path between the coil and the signal processing unit, the efficient reception of the energy from the electronic pen becomes difficult.
In addition, since the noise is intermixed when the transmission or receiving signal is passing through the switches, the calculation of the position becomes difficult.
Besides, high performance switches are required for an accurate selection of the transmitting and receiving channels, therefore it is difficult to provide low cost tablets to the market.
To overcome the problems described above, the objective of the invention is to provide a transmitter-receiver of a tablet that can efficiently send and receive energy to and from the electronic pen.
Another objective of the invention is to provide a transmitter-receiver of a tablet that can select the transmitting and receiving channels without using any switch.
In order to achieve above-described objectives, a transmitter-receiver of a tablet of the present invention is comprised of: an excitation signal generation unit for generating excitation signal that magnetizes the coils; a signal output circuit for alternatively outputting the excitation signal and the ground signal that enables the induced current to flow through the coil; a plurality of tri-state buffers for connecting the signal output circuit with the one ends of the coils; a buffer control unit for setting the output of the tri-state buffers either to a high impedance state or an enable state; a switching unit that turns on or off the connection between the other ends of the coils and the receiving signal amplifier that amplifies the induced current in the coil; and a switch control unit for controlling the switching unit.
A transmitter-receiver of a tablet of the present invention may further be comprised of a capacitor that connects the other ends of the coils with the ground.
A transmitter-receiver of a tablet of the present invention may further be comprised of a square wave generation unit for generating square wave signals that switches the energy transfer mode with the electronic pen from a transmission mode to a reception mode or vice versa, and outputting the square wave signals to the signal output circuit.
The signal output circuit may further be comprised of an AND circuit that outputs logic SUM of the excitation signal inputted from the excitation signal generation unit and the square wave signal inputted from the square wave generation unit.
According to the transmitter-receiver of a tablet of the present invention, it has following advantages in comparison with the conventional ones.
One advantage of the present invention is that there is no switch on the transmission path therefore the energy can be efficiently transmitted to electronic pen.
Another advantage of the present invention is that there is only one switch on the receiving path therefore the induced current inside the coil can be efficiently received.
Yet another advantage of the present invention is that the calculation of the position of the electronic pen is rather easy due to the low noise intermixing obtained by minimizing the switching operation.
Yet another advantage of the present invention is that the excitation signal can be resonated, and the frequency of the excitation signal can be tuned to the natural frequency of the electronic pen thereby making transmission-reception with the electronic pen more efficient.
FIG. 1 is a block diagram of a conventional transmitter-receiver of a tablet;
FIG. 2 is a block diagram of a transmitter-receiver of a tablet according to an exemplary embodiment of the present invention;
FIG. 3 illustrates various waveforms generated by the microprocessor of the present invention for transmitting and receiving the energy and the relevant timing relations;
FIG. 4 is a detailed block diagram of the receiving signal processing unit of the present invention; and
FIG. 5 is an illustration describing the calculation concept of the absolute position of the electronic pen.
<Description of reference numerals of principal elements in the drawings>
110: coil 120: tri-state buffer
130: microprocessor 131: excitation signal generation unit
132: square wave generation unit 133: buffer control unit
134: switch control unit 135: reset control unit
140: signal output circuit 150: decoder
160: capacitor 170: switching unit
180: receiving signal processing unit 181: receiving signal amplifier
182: rectifier 183: peak holding circuit
184: electronic pen position calculation unit
Hereinafter, according to an exemplary embodiment of the present invention, a transmitter-receiver of a tablet will be described in detail with reference to the accompanying drawings.
FIG. 2 is a block diagram of a transmitter-receiver of a tablet according to an exemplary embodiment of the present invention.
As shown in FIG. 2, a transmitter-receiver of a tablet of the present invention can be comprised of a plurality of coils 110, a plurality of tri-state buffers 120, a signal output circuit 140, a decoder 150, a capacitor 160, a switching unit 170, and a receiving signal processing unit 180.
The plurality of coils 110 are individually laid on the planar tablet horizontally or vertically.
There is one-to-one correspondence between the plurality of tri-state buffers 120 and the plurality of coils 110. As shown in FIG. 2, each output (Y) is connected with the one end of the coil. As is generally known, a tri-state buffer is a device whose output has an enable state and a high impedance (Hi-Z) state. In an enable state, the input signal is outputted as it is; in a high impedance state, the input signal is not outputted. In other words, the coil and the tri-state buffer are electrically isolated when the output of the tri-state buffer 120 is in a high impedance state. As such tri-state buffers, '74AC125' can be used.
FIG. 3 illustrates various waveforms generated by the microprocessor of the present invention for transmitting and receiving the energy and the relevant timing relations.
The microprocessor 130 can be comprised of an excitation signal generation unit 131, a square wave generation unit 132, a buffer control unit 133, a switch control unit 134, and a reset control unit 135.
The excitation signal generation unit 131 generates an excitation signal, an AC signal having a predetermined frequency as shown in FIG. 3, that magnetizes the coils, and outputs to the signal output circuit 140.
The square wave generation unit 132 generates square wave signals that switches the energy transfer mode with the electronic pen from a transmission mode to a reception mode or vice versa (hereinafter refer to as 'transmission-reception conversion signal': refer to in FIG. 3); and outputs to the signal output circuit 140. In the transmission-reception conversion signal, the high-level period is the period for energy transmission to the electronic pen, and the low-level period is the period for energy reception from the electronic pen. The transmission period can be determined by the quality factor Q of the resonance circuit of the electronic pen, and has a typical value between 150㎲ to 200㎲. The reception period has a typical value between 100㎲ to 150㎲.
The buffer control unit 133 alternatively enables the multiple tri-state buffers 120. In other words, the buffer control unit 133 changes the state of the buffer from enable state to high impedance state at the rising edge of the transmission-reception conversion signal, then changes the state of the next buffer from high impedance state to enable state.
The switch control unit 134 for controlling the switching unit 170 generates a switching control signal (refer to in FIG. 3); and outputs to the switching unit 170. As shown in FIG. 3, the switch control unit 134 starts to output a high-level signal to the switching unit 170 at the falling edge of the transmission-reception conversion signal (refer to in FIG. 3). Then, the switch control unit 134 stops outputting the high-level signal and starts outputting a low-level signal before the transmission-reception conversion signal (refer to in FIG. 3) reaches rising edge.
The reset control unit 135 for controlling the peak holding circuit 183 in FIG. 4, outputs reset signal (refer to in FIG. 3) for resetting the peak holding voltage during the low-level period of the switching control signal (refer to in FIG. 3).
The signal output circuit 140 alternatively outputs the excitation signal and the ground signal to the multiple tri-state buffers 120. Wherein the ground signal is a signal which grounds the one end of the coil 110 such that the induced current can flow through the coil 110. For example, if the reference voltage of the excitation signal is 0V (i.e. the excitation signal is an alternating signal with respect to 0V), the ground signal is a DC current having amplitude of 0V.
For such function, the signal output circuit 140 may further be comprised of an AND circuit that outputs logic SUM of the excitation signal inputted from the excitation signal generation unit 131 and the square wave signal inputted from the square wave generation unit 132. In other words, the AND circuit outputs the excitation signal inputted from the excitation signal generation unit 131 as it is when the transmission-reception conversion signal inputted from the square wave generation unit 132 is at a high-level; and outputs a ground signal when the transmission-reception conversion signal is at a low-level.
The decoder 150 sets the buffer selected by the buffer control unit 133 to an enable state, and sets the remaining buffers to a high impedance state. As such a decoder 150, '74HC138' can be used.
The capacitor 160, for enhancing the efficiency of the energy transmission and reception, connects the other end of the coil 110 with the ground. In other words, the capacitor 160 and the coil 110 forms a resonant circuit for the signal induced from the excitation signal and the electronic pen. In order to maximize such resonance, the natural frequency of the resonant circuit, the frequency of the excitation signal, and the natural frequency of the electronic pen should be identical.
The switching unit 170 connects the receiving signal processing unit 180 with the other end of the coil during the high-level input period from the switch control unit 134; while the switching unit 170 disconnects the receiving signal processing unit 180 from the other end of the coil, and connects the receiving signal processing unit 180 with the ground during the low-level input period from the switch control unit 134.
FIG. 4 is a detailed block diagram of the receiving signal processing unit of the present invention
As shown in FIG. 4, the receiving signal processing unit 180 may be comprised of a receiving signal amplifier 181, a rectifier 182, a peak holding circuit 183 and electronic pen position calculation unit 184.
The receiving signal amplifier 181 which can be implemented with an operational amplifier, amplifies the minute signal (refer to ⓐ in FIG. 4) being induced in the coil 110 by using a dual power supply (+5V, -5V).
The rectifier 182 which can be implemented with a diode, rectifies the signal (refer to ⓑ in FIG. 4) which is amplified by the receiving signal amplifier 181.
As shown in FIG. 4, the peak holding circuit 183 may be comprised of two operational amplifiers, a diode, a capacitor, and a transistor; and is a circuit that outputs a peak value (i.e. holds the peak value) of the input signal inputted from the rectifier 182. The two operational amplifiers use a single power supply (5V). The front-end operational amplifier amplifies the signal inputted from the rectifier 182. The back-end operational amplifier outputs a peak value of the signal (refer to ⓒ in FIG. 4) which is amplified by the front-end operational amplifier. The transistor is a circuit element for discharging the capacitor. In other words, the transistor resets the peak value which is held by the back-end operational amplifier, through discharging of the capacitor when the reset signal is received from the microprocessor 130.
The electronic pen position calculation unit 184 calculates the position of the electronic pen by using the pre-stored absolute position value of the coil 110 and the voltage value of the signal inputted from the peak holding circuit 183.
Meanwhile, time (t) in the waveforms shown in FIG. 4 is the time when the mode is being changed from transmission to reception, in other words, the time when the receiving signal processing unit 180 is connected with the other end of the coil 110.
FIG. 5 is an illustration describing the calculation concept of the absolute position of the electronic pen.
Although it is described as if the coils are placed apart from each other with a constant separation distance in FIG. 2, actually the coils are overlapped with the neighboring coils. As shown in FIG. 5, the electronic pen position calculation unit 184 determines the relative position of the electronic pen (x0) by comparing the voltages induced in each coil being inputted from the peak holding circuit 183. Then the absolute position value of the electronic pen is calculated by using the absolute position values of the individual coils.
The transmitter-receiver of a tablet of the present invention is not limited by the above-described exemplary embodiments, and various changes and modification may be made thereto, without departing from the scope and spirit of the present invention.

Claims (3)

  1. A transmitter-receiver of a tablet comprising:
    an excitation signal generation unit for generating excitation signal that magnetizes the coils;
    a signal output circuit for alternatively outputting the excitation signal and the ground signal that enables the induced current to flow through the coil;
    a plurality of tri-state buffers for connecting the signal output circuit with the one ends of the coils;
    a buffer control unit for setting the output of the tri-state buffers either to a high impedance state or an enable state;
    a switching unit that turns on or off the connection between the other ends of the coils and the receiving signal amplifier that amplifies the induced current in the coil; and
    a switch control unit for controlling the switching unit.
  2. The transmitter-receiver of a tablet as set forth in claim 1,
    further comprising a capacitor that connects the other ends of the coils with the ground.
  3. The transmitter-receiver of a tablet as set forth in claim 1,
    further comprising a square wave generation unit,
    wherein the signal generation unit comprises an AND circuit that outputs logic SUM of the excitation signal inputted from the excitation signal generation unit and the square wave signal inputted from the square wave generation unit.
PCT/KR2011/001143 2010-02-23 2011-02-22 Transmitter-receiver of a tablet WO2011105727A2 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
KR1020100016071A KR101071327B1 (en) 2010-02-23 2010-02-23 transmitter-receiver of a tablet
KR10-2010-0016071 2010-02-23

Publications (2)

Publication Number Publication Date
WO2011105727A2 true WO2011105727A2 (en) 2011-09-01
WO2011105727A3 WO2011105727A3 (en) 2012-01-12

Family

ID=44507355

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/KR2011/001143 WO2011105727A2 (en) 2010-02-23 2011-02-22 Transmitter-receiver of a tablet

Country Status (2)

Country Link
KR (1) KR101071327B1 (en)
WO (1) WO2011105727A2 (en)

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4479032A (en) * 1982-02-08 1984-10-23 Bausch & Lomb Incorporated Digitizing cursor and coordinate grid system
US4678869A (en) * 1985-10-25 1987-07-07 Scriptel Corporation Position responsive apparatus, system and method having electrographic application
US5600105A (en) * 1993-12-28 1997-02-04 Wacom Co., Ltd. Position detecting device and position pointing device therefor
KR20090123647A (en) * 2008-05-28 2009-12-02 유영기 Tablet system and control method for the same

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4479032A (en) * 1982-02-08 1984-10-23 Bausch & Lomb Incorporated Digitizing cursor and coordinate grid system
US4678869A (en) * 1985-10-25 1987-07-07 Scriptel Corporation Position responsive apparatus, system and method having electrographic application
US5600105A (en) * 1993-12-28 1997-02-04 Wacom Co., Ltd. Position detecting device and position pointing device therefor
KR20090123647A (en) * 2008-05-28 2009-12-02 유영기 Tablet system and control method for the same

Also Published As

Publication number Publication date
WO2011105727A3 (en) 2012-01-12
KR20110096695A (en) 2011-08-31
KR101071327B1 (en) 2011-10-07

Similar Documents

Publication Publication Date Title
CN109478794B (en) Wireless charging system with multi-coil receiver
WO2013129869A1 (en) Method and apparatus for wirelessly charging multiple wireless power receivers
CN202268816U (en) Power converter and electronic device
US7304405B2 (en) Electrically isolated power and signal coupler system for a patient connected device
US9837848B2 (en) Foreign-object detection for resonant wireless power system
US8952654B2 (en) Feed system, feed apparatus, and electronic device
WO2017023093A1 (en) Wireless power transmission device and system using impedance matching
WO2013069951A4 (en) Wireless power transmission and receiving system capable of multi charge
WO2012169769A2 (en) Wireless power-transmission apparatus and system
WO2013151259A1 (en) Device and system for wireless power transmission using transmission coil array
WO2013115419A1 (en) Wireless power transmission apparatus capable of matching impedance
WO2013165165A1 (en) Wireless power transmission device, wireless power relay device, and wireless power transmission system
US20180115184A1 (en) Wireless charging adapter
WO2016114629A1 (en) Wireless power transmission device
US8981713B2 (en) Charging apparatus using pad type electrode contact point
KR101504068B1 (en) Transmission system for providing customized wireless recharge
JP2016090581A (en) Power measuring device and power measuring method, and electric leak detection device and electric leak detection method
WO2015167055A1 (en) Wireless power relay device and wireless power transmission system
US11411611B2 (en) Communication device and method for operating the same
WO2011105727A2 (en) Transmitter-receiver of a tablet
WO2013048036A1 (en) Wireless power repeater and wireless power transmitter
CN103683849B (en) There is the power supply changeover device of intelligent radio charge function
DK176584B1 (en) Headset with rechargeable battery, base unit designed to charge a rechargeable battery as well as a communication device
CN108112273A (en) Voltameter and the adaptor module for it
CN102640393B (en) For the power bridge circuit that two-way inductance signal transmits

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 11747617

Country of ref document: EP

Kind code of ref document: A2

NENP Non-entry into the national phase in:

Ref country code: DE

32PN Ep: public notification in the ep bulletin as address of the adressee cannot be established

Free format text: NOTING OF LOSS OF RIGHTS PURSUANT TO RULE 112(1) EPC (EPO FORM 1205N DATED 30/10/2012)

122 Ep: pct application non-entry in european phase

Ref document number: 11747617

Country of ref document: EP

Kind code of ref document: A2