MULTI-CHANNEL CONTACT SENSING APPARATUS

• US 20130113743A1
• Filed: 11/09/2012
• Published: 05/09/2013
• Est. Priority Date: 11/09/2011
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: HAN, Dong-Kyoon
• Granted Patent: US 9,632,644 B2
• Time in Patent Office: Days
• US Class Current: 345/173
• 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 3/046 by electromagnetic means

Abstract

A multi-channel contact sensing apparatus includes a ground contact part, a loop unit including a transmitting sub-loop unit and a receiving sub-loop unit, a controller that controls by applying a transmission signal to the transmitting sub-loop unit, and receiving a reception signal from the receiving sub-loop unit, and a switch unit that prevents each of at least one loop of the transmitting sub-loop unit and at least one loop of the receiving sub-loop unit from being connected to the ground contact part during a first period. The multi-channel contact sensing apparatus simultaneously measures a finger touch input and a pen input.

Claims

1. A sensing apparatus, comprising:

a ground contact part;

a loop unit including a transmitting sub-loop unit and a receiving sub-loop unit;

a controller that controls by applying a transmission signal to the transmitting sub-loop unit, and receiving a reception signal from the receiving sub-loop unit; and

a switch unit that prevents each of at least one loop of the transmitting sub-loop unit and each of at least one loop of the receiving sub-loop unit from being connected to the ground contact part during a first period,

wherein the controller controls such that a plurality of loops of the transmitting sub-loop unit and a plurality of loops of the receiving sub-loop unit are connected to the ground contact part during a second period.

2. The apparatus of claim 1, wherein the controller applies the transmission signal to the transmitting sub-loop unit, and simultaneously, receives the reception signal from the receiving sub-loop unit during the first period.

3. The apparatus of claim 1, wherein the controller comprises a location determining unit that determines, based on the reception signal input from the receiving sub-loop unit, a location of an area input from an external side of the sensing apparatus during the first period and a location of a pen input during the second period.

4. The apparatus of claim 3, wherein the location determining unit receives the area input inputted from the external side and analyzes the received area input during the first period.

5. The apparatus of claim 4, wherein the location determining unit analyzes the area input based on a change in a strength of the reception signal input from the transmitting sub-loop due to the area input.

6. The apparatus of claim 5, wherein the area input corresponds to a finger touch of a user;

and

the location determining unit determines a touch location of the finger touch based on a decrease in a strength of the reception signal due to the finger touch.

7. The apparatus of claim 3, wherein the location determining unit comprises:

an amplifying unit that amplifies the reception signal and outputs a single-ended amplified signal;

a differential signal converting unit that converts the single-ended amplified signal and outputs two differential signals;

a differential rectifying unit that rectifies each of the two differential signals; and

a calculator that calculates a voltage level difference between the two rectified differential signals, and calculates the location of the area input or the location of the pen input based on a result of the voltage level difference calculation.

8. The apparatus of claim 7, wherein the location determining unit further comprises:

a low-pass filter unit that performs low-pass filtering on the two differential signals; and

an analog-to-digital converter unit that performs analog-to-digital converting on the two low-pass filtered differential signals for outputting to the calculator.

9. The apparatus of claim 1, wherein the controller alternately applies the transmission signal to the transmitting sub-loop unit and reception of the reception signal from the receiving sub-loop unit during the second period.

10. The apparatus of claim 1, wherein the controller comprises a frequency determining unit that determines a touch pressure of a pen input inputted during the second period, based on the reception signal input from the reception sub-loop unit.

11. The apparatus of claim 10, wherein the frequency determining unit comprises:

a signal waveform extracting unit that extracts a signal waveform from the reception signal;

at least one delay unit that delays the extracted signal waveform by a phase; and

a comparing unit that compares at least one delay signal delayed by the at least one delay unit and the signal waveform.

12. The apparatus of claim 11, wherein the frequency determining unit determines phase information of the reception signal based on a binary signal associated with a result of the comparison of the comparing unit, and determines the touch pressure based on the phase information.

13. The apparatus of claim 1, wherein the switch unit comprises:

a first switch of which one end is connected to one end of each of the plurality of loops of the transmitting sub-loop unit; and

a second switch of which one end is connected to one end of each of the plurality of loops of the receiving sub-loop unit.

14. The apparatus of claim 13, wherein another end of each of the first and second switches is connected to the ground contact part.

15. The apparatus of claim 14, wherein the controller controls such that the first and second switches are opened during the first period, and the first and second switches are closed during the second period.

16. The apparatus of claim 1, wherein the switch unit comprises a plurality of switches, each of which is connected to one end of one of the plurality of loops of the transmitting sub-loop unit and the plurality of loops of the receiving sub-loop unit.

17. A location sensing module that is connected to a sensing loop and determines an input location based on a single-ended reception signal from the sensing loop, the module comprising:

a differential signal converting unit that converts the single-ended reception signal into two differential signals that are inverted to each other and outputs the two differential signals;

a differential rectifying unit that outputs two rectified signals by rectifying the two differential signals; and

a calculator that determines an input location of the sensing loop based on a strength difference between the two rectified signals.

18. The module of claim 17, further comprising:

an amplifier that amplifies the reception signal and outputs a single-ended amplified signal;

a low-pass filter unit that performs low-pass filtering on the two differential signals; and

an analog-to-digital converter unit that performs analog-to-digital converting on the two low-pass filtered differential signals and outputs the converted signals to the calculator.