Method of determining adaptive DPI curve

Patent metadata

Field	Value
Publication number	US-10379638-B2
Application number	US-201514593043-A
Country	US
Kind code	B2
Filing date	Jan 9, 2015
Priority date	Jan 23, 2014
Publication date	Aug 13, 2019
Grant date	Aug 13, 2019

Abstract

A method of determining an adaptive DPI curve includes the steps of: detecting, by a sensing element, an object on a touch surface and outputting a detected frame; calculating, by a processing unit, a contact range according to the detected frame; and determining a DPI curve according to the contact range.

First claim

What is claimed is:

1. A method of determining an adaptive dots per inch (DPI) function, the method comprising:
detecting, by a sensing element, a first object in contact with a touch surface at a first time, and outputting first detected data;
calculating, by a processing unit, a first contact range corresponding to the first object on the touch surface according to the first detected data;
detecting, by the sensing element, a second object in contact with the touch surface at a second time, and outputting second detected data;
calculating, by the processing unit, a second contact range corresponding to the second object on the touch surface according to the second detected data; and
determining a DPI function according to a variation between the calculated second contact range of the second object and the calculated first contact range of the first object on the touch surface.

2. The method as claimed in claim 1 , further comprising:
determining an initial DPI function according to the first contact range.

3. The method as claimed in claim 1 , wherein in the determining, the processing unit selects one of a plurality of DPI functions according to the variation.

4. The method as claimed in claim 1 , wherein the first contact range and the second contact range are respectively obtained according to a comparison result between variations of a plurality of detection units and a threshold.

5. The method as claimed in claim 1 , wherein the first contact range and the second contact range are respectively calculated according to a variation curve of a sum of intensities of each column or each row of the first detected data and the second detected data.

6. The method as claimed in claim 1 , wherein the variation is a difference value or a quotient between the second contact range and the first contact range.

7. The method as claimed in claim 1 , wherein the first contact range and the second contact range are contact widths, contact lengths or contact areas, and the sensing element is a capacitive touch sensor, a resistive touch sensor or an optical touch sensor.

Assignees

• Pixart Imaging Inc

Inventors

• Liao Chi-Chieh
• Lin Han-Shu
• Su Tse-Chung

Classifications

• G06F3/038 Primary

  Control and interface arrangements therefor, e.g. drivers or device-embedded control circuitry · CPC title

• G06F3/03547

  Touch pads, in which fingers can move on a surface · CPC title

• G06F3/0416

  Control or interface arrangements specially adapted for digitisers · CPC title

• G06F3/0213

  Arrangements providing an integrated pointing device in a keyboard, e.g. trackball, mini-joystick (for pointing devices integrated in a laptop computer G06F1/169; joysticks G05G9/047; constructional details of pointing devices G06F3/033) · CPC title

• G06F3/041661

  using detection at multiple resolutions, e.g. coarse and fine scanning; using detection within a limited area, e.g. object tracking window · CPC title