Method and device for position detection

• US 10,061,459 B2
• Filed: 05/23/2017
• Issued: 08/28/2018
• Est. Priority Date: 10/09/2009
• Status: Active Grant

• Current Assignee: eGalax_eMPIA Technology Inc.
• Original Assignee: eGalax_eMPIA Technology Inc.
• Inventors: Chang, Chin-Fu, Lee, Cheng-Han, Tang, Chi-Hao, Ho, Shun-Lung
• Primary Examiner(s): Awad, Amr
• Assistant Examiner(s): MATTHEWS, ANDRE L
• Application Number:
  US15/602,286
• Publication Number:
  US 20170254843A1
• Time in Patent Office: 462 Days
• CPC Class Codes: G01R 27/2605 Measuring capacitance capacitive sensors G01D5/24
• CPC Class Codes: G06F 2203/04101 2.5D-digitiser, i.e. digitiser detecting the X/Y position of the input means, finger or stylus, also when it does not touch, but is proximate to the digitiser's interaction surface and also measures the distance of the input means within a short range in the Z direction, possibly with a separate measurement setup
• CPC Class Codes: G06F 2203/04102 Flexible digitiser, i.e. constructional details for allowing the whole digitising part of a device to be flexed or rolled like a sheet of paper
• CPC Class Codes: G06F 2203/04103 Manufacturing, i.e. details related to manufacturing processes specially suited for touch sensitive devices
• CPC Class Codes: G06F 2203/04104 Multi-touch detection in digitiser, i.e. details about the simultaneous detection of a plurality of touching locations, e.g. multiple fingers or pen and finger
• 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 2203/04111 Cross over in capacitive digitiser, i.e. details of structures for connecting electrodes of the sensing pattern where the connections cross each other, e.g. bridge structures comprising an insulating layer, or vias through substrate
• CPC Class Codes: G06F 3/03545 Pens or stylus
• CPC Class Codes: G06F 3/041 Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• 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 3/04184 Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally
• CPC Class Codes: G06F 3/0445 using two or more layers of sensing electrodes, e.g. using two layers of electrodes separated by a dielectric layer
• 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 3/047 using sets of wires, e.g. crossed wires

Abstract

The method and device for position detection are disclosed. Corresponding to a first touch related sensing information, a second touch related sensing information is acquired for determining at least one position. Each position is used separately for determining the position of a centroid according to the first touch related sensing information or the second touch related sensing information.

Claims

1. A processor for determining centroid positions, executing:

obtaining a corresponding baseline by each of a plurality of sensors when there is no touch or proximity of an external object;

performing the following steps when there is a touch or proximity of the external object;

obtaining a first touch related sensing information by subtracting the corresponding baseline from each value of a sensing information;

obtaining at least one position;

determining a corresponding first calculation range in the first touch related sensing information based on each position;

determining a base value local to a touch or proximity of the external object based on the first calculation range, wherein the base value is the difference between the corresponding baseline and a signal of one sensor touched or approached by the external object or the difference between the corresponding baseline and a dual-differential signal of three sensors touched or approached by the external object;

generating a set of calculation values by subtracting the same base value from all the values in the first calculation range; and

calculating a centroid position based on the set of calculation values.

2. The processor of claim 1, wherein values of the first touch related sensing information correspond to signals of a plurality of sensors or signals of a single sensor at a plurality of time points.

3. The processor of claim 1, wherein values of the first touch related sensing information correspond to dual-differential signals of a plurality of sensors or dual-differential signals of a single sensor at a plurality of time points.

4. The processor of claim 1, wherein the first touch related sensing information is converted from a second touch related sensing information, and each first value of the first touch related sensing information corresponding to a second value of the second touch related sensing information, wherein the first value is an accumulation of the second value with all the values preceding or following the second value.

5. The processor of claim 4, wherein the at least one position is determined based on at least one zero-crossing in the second touch related sensing information, wherein each zero-crossing is between a pair of positive and negative values of the second touch related sensing information.

6. The processor of claim 1, wherein the first touch related sensing information is converted from a second touch related sensing information, and each value of the second touch related sensing information being a dual difference, each dual difference being generated based on signals of three sensors from a plurality of sensors or signals of one sensor at three of a plurality of time points.

7. The processor of claim 6, wherein the three sensors are adjacent.

8. The processor of claim 6, wherein the three sensors are non-adjacent.

9. The processor of claim 1, wherein the each position is determined based two zero-crossings in the second touch related sensing information, wherein each zero-crossing is between a pair of positive and negative values of the second touch related sensing information.