TABLET CAPABLE OF SENSING LOCATION USING ELECTROMAGNETIC INDUCTION AND ELECTROSTATIC CAPACITANCE

• US 20160179134A1
• Filed: 07/02/2014
• Published: 06/23/2016
• Est. Priority Date: 07/03/2013
• Status: Active Grant

• Current Assignee: The Han Inc.
• Original Assignee: The Han Inc.
• Inventors: RYU, Young Kee
• Granted Patent: US 9,772,660 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 1/169 the I/O peripheral being an integrated pointing device, e.g. trackball in the palm rest area, mini-joystick integrated between keyboard keys, touch pads or touch stripes G06F1/1643 takes precedence; constructional details of pointing devices G06F3/033
• CPC Class Codes: G06F 2203/04106 Multi-sensing digitiser, i.e. digitiser using at least two different sensing technologies simultaneously or alternatively, e.g. for detecting pen and finger, for saving power or for improving position detection
• CPC Class Codes: G06F 3/03545 Pens or stylus
• CPC Class Codes: G06F 3/038 Control and interface arrangements therefor, e.g. drivers or device-embedded control circuitry
• CPC Class Codes: G06F 3/04166 Details of scanning methods, e.g. sampling time, grouping of sub areas or time sharing with display driving Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally G06F3/04184
• CPC Class Codes: G06F 3/0446 using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes
• CPC Class Codes: G06F 3/046 by electromagnetic means

Abstract

The present invention relates to a tablet capable of sensing a location using electromagnetic induction and electrostatic capacitance. The tablet comprises: a loop antenna, having a closed-loop shape for surrounding a sensing area, capable of sensing an electromagnetic wave emitted from an electronic pen; a first line antenna provided with a plurality of first conductive patterns, both ends of each of the plurality of first conductive patterns being located on one side of the first line antenna; a second line antenna provided with a plurality of second conductive patterns which cross the plurality of first conductive patterns in the sensing area, both ends of each of the plurality of second conductive patterns being located on the side on which the both ends of each of the plurality of first conductive patterns are located; and a control circuit for sensing a location using electromagnetic induction and electrostatic capacitance by controlling a connection relation between the plurality of first conductive patterns and the plurality of second conductive patterns. Accordingly, it is possible to selectively recognize the manipulation of the electronic pen and the touch of a finger with the same antenna pattern.

Claims

1. A tablet capable of performing location sensing in an electromagnetic induction method and location sending in an electrostatic capacitance method, the tablet comprising:

a loop antenna surrounding at least a part of a sensing area where an electromagnetic wave radiated by an electric pen is sensible;

first line antennas having a plurality of first conductive patterns arranged in the sensing area;

second line antennas having a plurality of second conductive patterns crossing the plurality of first conductive patterns in the sensing area; and

a control circuit comprising switch devices controlling one end and the other end of each of the plurality of first conductive patterns and switch devices controlling one end and the other end of each of the plurality of second conductive patterns, and controlling connections of opposite ends of each of the plurality of first conductive patterns and the plurality of second conductive patterns by controlling the switch devices, whereby location sensing is performed by an electromagnetic induction method or an electrostatic capacitance method.

2. The tablet of claim 1, wherein, when location sensing is performed in an electrostatic capacitance method, the control circuit controls the switch devices connected to one end and the other end of each of the plurality of first conductive patterns so that the other end of each of the plurality of first conductive patterns is opened or feedback connected to the one end, and controls the switch devices connected to one end and the other end of each of the plurality of second conductive patterns so that the other end of each of the plurality of second conductive patterns is opened or feedback connected to the one end.

3. The tablet of claim 1, further comprising a transmission circuit transmitting a drive signal of a certain waveform and a receiving circuit receiving a sensing signal transferred by the drive signal of the transmission circuit,

wherein, when location sensing is performed in an electrostatic capacitance method, the control circuit controls the switch devices connected to one end and the other end of each of the plurality of first conductive patterns so that the drive signal of the transmission circuit is supplied to one end of at least one of the plurality of first conductive patterns, and controls the switch devices connected to one end and the other end of each of the plurality of second conductive patterns so that the receiving circuit receives a sensing signal transferred to the second conductive patterns by the drive signal of the transmission circuit.

4. The tablet of claim 1, wherein, when location sensing is performed in an electromagnetic induction method, the control circuit controls the switch devices connected to one end and the other end of each of the plurality of first conductive patterns so that the other end of each of the plurality of first conductive patterns is connected to the loop antenna, and controls the switch devices connected to one end and the other end of each of the plurality of second conductive patterns so that the other end of each of the plurality of second conductive patterns is connected to the loop antenna.

5. The tablet of claim 1, further comprising a differential amplifier outputting an electric potential difference between the loop antenna and an induction signal electromagnetically induced by the electric pen in the first line antennas and the second line antennas,

wherein, when location sensing is performed in an electromagnetic induction method, the control circuit controls the switch devices connected to one end and the other end of each of the plurality of first conductive patterns and the plurality of second conductive patterns so that an induction signal electromagnetically induced by the electric pen in the first line antennas and the second line antennas is supplied to the differential amplifier.

6. The tablet of claim 1, when location sensing is performed in an electromagnetic induction method, further comprising a selector connecting the loop antenna to the ground or a common electric potential or opening a closed loop of the loop antenna.

7. The tablet of claim 1, wherein a substrate where the plurality of first conductive patterns and the plurality of second conductive patterns are formed and the control circuit comprising the switch devices are formed on different substrates.

8. The tablet of claim 1, wherein the plurality of first conductive patterns and the plurality of second conductive patterns are formed on one surface of one substrate in an insulation state, respectively formed on one surface and the other surface of one substrate, or formed on different substrates.

9. The tablet of claim 1, wherein the loop antenna is formed on any one of first substrate and second substrate or on a separate third substrate.

10. The tablet of claim 9, wherein a power coil radiating an electromagnetic force with respect to the electric pen is formed on any one of the first to third substrates or on a separate fourth substrate.

11. The tablet of claim 10, wherein the power coil comprises a plurality of coil patterns arranged by dividing a certain area in a horizontal direction or vertical direction, or in horizontal and vertical directions.