Detection method and device for touch screen

• US 9,874,981 B2
• Filed: 12/26/2013
• Issued: 01/23/2018
• Est. Priority Date: 12/28/2012
• Status: Active Grant

• Current Assignee: eGalax_eMPIA Technology Inc.
• Original Assignee: eGalax_eMPIA Technology Inc.
• Inventors: Yeh, Shang-Tai
• Primary Examiner(s): Edouard, Patrick
• Assistant Examiner(s): Shen, Peijie
• Application Number:
  US14/140,810
• Publication Number:
  US 20140198075A1
• Time in Patent Office: 1,489 Days
• CPC Class Codes: G06F 2203/04108 Touchless 2D- 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 without distance measurement in the Z direction
• 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 3/0442 using active external devices, e.g. active pens, for transmitting changes in electrical potential to be received by the digitiser
• 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

Abstract

A detection method and device for a touch screen is provided. When a pen touching or approaching the touch screen is detected, only the location of the pen in a predetermined range is provided, and the locations of all other objects within the predetermined range are not provided, such as the location of a palm. Only when the pen is no longer detected over a predetermined period of time, then the locations of objects other than the pen in the predetermined range are provided again.

Claims

1. A detection device for a touch screen, comprising:

the touch screen for detecting signals for approaches or touches of external conductive objects thereon;

a controller for recording a location of a first pen and generating a first predetermined range corresponding to the location of the first pen if determined that at least one external conductive object is a pen based on the signals on the touch screen; and

a memory for storing a flag corresponding to the first pen and the first predetermined range of the first pen, wherein the flag is set to a true value if the existence of the first pen is detected by the controller, and the flag is set to a false value only if the existence of the first pen is not detected by the controller over a predetermined period of time, wherein a location of the first predetermined range remains at a latest generated location of the first predetermined range if the first pen corresponding to the flag being set to the true value is not detected during the predetermined period of time,

wherein the controller outputs the location of the first pen and any external conductive object outside the first predetermined range, but does not output the locations of one or more external conductive objects other than the first pen in the first predetermined range corresponding to a flag being set to the true value;

wherein the first predetermined range is smaller than an area of the whole touch screen.

2. The detection device of claim 1, wherein the first predetermined range moves with the location of the first pen.

3. The detection device of claim 1, wherein the controller deletes a flag being set to the false value, and when a second pen without a corresponding flag is detected, the controller adds a flag for the location of the second pen.

4. A detection method for a touch screen, comprising:

providing signals for approaches or touches of external conductive objects on a touch screen;

recording a location of a first pen and generating a first predetermined range corresponding to the location of the first pen if determined that at least one external conductive object is a pen based on the signals on the touch screen;

providing a flag corresponding to the location of the first pen, and the flag corresponding to the first predetermined range of the location of the first pen;

setting the flag to a true value when the location of the first pen is detected;

keeping a location of the first predetermined range at a latest generated location of the first predetermined range when the first pen corresponding to the flag being set to the true value is not detected during a predetermined period of time;

setting the flag to a false value only if the first pen is not detected over the predetermined period of time; and

outputting the location of the first pen and the location of each external conductive object other than the first pen outside the first predetermined range, and not output the locations of one or more external conductive objects other than the first pen in the first predetermined range corresponding to the flag being set to the true value;

wherein the first predetermined range is smaller than an area of the whole touch screen.

5. The detection method of claim 4, wherein the first predetermined range moves with the location of the first pen.

6. The detection method of claim 4, wherein a flag being set to the false value is deleted, and when the location of a second pen without a corresponding flag is detected, a flag for the location of the second pen is added.