Mutual capacitance touch sensing device and its sine wave measuring method

• US 9,766,759 B2
• Filed: 12/23/2014
• Issued: 09/19/2017
• Est. Priority Date: 12/31/2013
• Status: Active Grant

• Current Assignee: eGalax_eMPIA Technology Inc.
• Original Assignee: eGalax_eMPIA Technology Inc.
• Inventors: Chang, Chin-Fu
• Primary Examiner(s): Li, Lin
• Application Number:
  US14/581,117
• Publication Number:
  US 20150185922A1
• Time in Patent Office: 1,001 Days
• Field of Search: 363 39, 345173
• 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 3/04182 Filtering of noise external to the device and not generated by digitiser components
• CPC Class Codes: G06F 3/044 by capacitive means
• 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

Abstract

A mutual capacitance touch sensing device and a sine wave measuring method is disclosed. A sine wave generator of a driver and sensor module of a touch sensing panel of the mutual capacitance touch sensing device uses a clock to generate multiple sine waves according to a lookup table being loaded therein, enabling a selective circuit to transmit the sine waves to driving lines of the touch sensing panel in a proper order so that each sine wave at each driving line is capacitive-coupled to a respective sensing line through a respective crossover point to produce a respective sensing signal, and then a measurement unit scans the generated sensing signal subject to the lookup table in the sine wave generator and then provides the measured signals to a processor for processing.

Claims

1. A sine wave measuring method used in a mutual capacitance touch sensing device comprising a touch sensing panel having arranged therein a plurality of driving lines extending along a first axis in a parallel manner and a plurality of sensing lines extending along a second axis in a parallel manner and crossed over said driving lines to form a plurality of crossover points, a driver and sensor module, said driver and sensor module comprising a selective circuit electrically connected with said driving lines, a measurement unit electrically connected with said sensing lines and a sine wave generator electrically connected with said selective circuit and said measurement unit and having a lookup table loaded therein, and a processor electrically connected with said measurement unit, the sine wave measuring method comprising the steps of:

(A01) said sine wave generator using a clock to generate multiple sine waves according to said lookup table, and then transmitting generated sine waves to said selective circuit;

(A02) said selective circuit transmitting said sine waves to said driving lines of said touch sensing panel in a proper order;

(A03) each said sine wave at each said driving line being capacitive-coupled to the respective said sensing line through the respective said crossover point to produce a respective sensing signal at the respective said crossover point; and

(A04) said measurement unit scanning the generated sensing signal at each said sensing line subject to said lookup table in said sine wave generator, so as to obtain the generated sensing signals at the respective said crossover points,

wherein said lookup table being loaded in said sine wave generator is established using a sine wave differential technique to differentiate each sine wave into a plurality of segments each corresponding to one respective phase where the integer multiple of the sine value of each said phase is a predetermined voltage value of the respective phase, and multiple particular phases are marked as predetermined measuring phases, and

wherein said predetermined measuring phases are 30°

, 90°

, 150°

, 210°

, 270° and

330°

.

2. The sine wave measuring method as claimed in claim 1, wherein when said selective circuit transmits multiple sine waves to said driving lines of said touch sensing panel, the sinusoidal quantity receivable by said driving lines is relatively increased to enhance signal intensity subject to the increase in distance between each said driving line and said measurement unit.

3. The sine wave measuring method as claimed in claim 1, wherein said driver and sensor module of said mutual capacitance touch sensing device comprises a plurality of channels electrically connected with said sensing lines, and a plurality of current-to-voltage converters respectively electrically connecting said channels to said processor.

4. The sine wave measuring method as claimed in claim 1, wherein said driver and sensor module of said mutual capacitance touch sensing device comprises a plurality of channels electrically connected with said sensing lines, and a plurality of analog-to-digital converters respectively electrically connecting said channels to said processor.

5. The sine wave measuring method as claimed in claim 1, wherein said driver and sensor module of said mutual capacitance touch sensing device comprises a plurality of channels electrically connected with said sensing lines, and a plurality of subtraction circuits electrically connecting said channels to said processor, each said subtraction circuit being coupled between a predetermined multiple adjacent channels of said driver and sensor module.

6. A mutual capacitance touch sensing device comprising:

a touch sensing panel comprising a plurality of driving lines extending from a first axis in a parallel manner, and a plurality of sensing lines extending from a second axis in a parallel manner, said sensing lines crossed over said driving lines to form a plurality of crossover points;

a driver and sensor module, said driver and sensor module comprising a selective circuit electrically connected with said driving lines, a measurement unit electrically connected with said sensing lines, a sine wave generator electrically connected with said selective circuit and adapted for generating sine waves according to a lookup table being loaded therein and a measurement unit electrically connected with said sine wave generator and adapted for scanning each sensing signal generated at the crossover point at each said sensing line subject to said lookup table in said sine wave generator; and

a processor electrically connected with said measurement unit,

wherein said lookup table being loaded in said sine wave generator is established using a sine wave differential technique to differentiate each sine wave into a plurality of segments each corresponding to one respective phase where the integer multiple of a sine value of each said phase is a predetermined voltage value of the respective phase, and multiple particular phases are marked as predetermined measuring phases, and

wherein said predetermined measuring phases are 30°

, 90°

, 150°

, 210°

, 270° and

330°

.

7. The mutual capacitance touch sensing device as claimed in claim 6, wherein when said selective circuit transmits multiple sine waves to said driving lines of said touch sensing panel, the sinusoidal quantity receivable by said driving lines is relatively increased to enhance signal intensity subject to the increase in distance between each said driving line and said measurement unit.

8. The mutual capacitance touch sensing device as claimed in claim 6, wherein said driver and sensor module of said mutual capacitance touch sensing device comprises a plurality of channels electrically connected with said sensing lines, and a plurality of current-to-voltage converters respectively electrically connecting said channels to said processor.

9. The mutual capacitance touch sensing device as claimed in claim 6, wherein said driver and sensor module of said mutual capacitance touch sensing device comprises a plurality of channels electrically connected with said sensing lines, and a plurality of analog-to-digital converters respectively electrically connecting said channels to said processor.

10. The mutual capacitance touch sensing device as claimed in claim 6, wherein said driver and sensor module of said mutual capacitance touch sensing device comprises a plurality of channels electrically connected with said sensing lines, and a plurality of subtraction circuits electrically connecting said channels to said processor, each said subtraction circuit being coupled between a predetermined multiple adjacent channels of said driver and sensor module.