IDENTIFICATION METHOD FOR SIMULTANEOUSLY IDENTIFYING MULTIPLE TOUCH POINTS ON TOUCH SCREENS

• US 20130033449A1
• Filed: 04/23/2010
• Published: 02/07/2013
• Est. Priority Date: 03/26/2010
• Status: Active Grant

• Current Assignee: Weishan Chen
• Original Assignee: Weishan Chen
• Inventors: Chen, Weishan
• Granted Patent: US 9,024,896 B2
• Time in Patent Office: Days
• US Class Current: 345/173
• 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 2203/04808 Several contacts: gestures triggering a specific function, e.g. scrolling, zooming, right-click, when the user establishes several contacts with the surface simultaneously; e.g. using several fingers or a combination of fingers and pen
• 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 3/0421 by interrupting or reflecting a light beam, e.g. optical touch-screen

Abstract

An identification method for simultaneously identifying multiple touch points on a touch screen, which includes the following steps: a first step, mounting some optical signal transmitting terminals and some optical signal receiving terminals around the touch screen; a second step, when some touch points appear on the touch screen, performing horizontal and vertical scans to get a preliminary location region; a third step, performing maximum positive inclination revising on the preliminary location region in the second step; a fourth step, performing maximum negative inclination revising on the region in the third step; a fifth step, some said optical signal transmitting terminals transmit optical signal in turn, inclination corresponding receiving terminals correspond to some said optical signal transmitting terminals are controlled in a receiving state in turn; a sixth step, filtering the locations of touch points in the fifth step, removing error points off, finally determining the location results of some said touch points, and finishing the whole identification process.

Claims

1. An identification method for simultaneously identifying multiple touch points on a touch screen, comprising:

a first step, arranging a plurality of optical signal emitting terminals and a plurality of optical signal receiving terminals around a display surface, the optical signal emitting terminals forming optical signal emitting units, the optical signal receiving terminals forming optical signal receiving units, the optical signal emitting units and the optical signal receiving units being arranged at opposite edges of the display surface;

one optical signal emitting terminal corresponding to at least three optical signal receiving terminals, that is, the optical signal emitted by the optical signal emitting terminal can be simultaneously received by at least three optical signal receiving terminals, distances of each pair of adjacent optical signal receiving terminals being identical;

the optical signal receiving terminal corresponding to the optical signal emitting terminal comprising a vertical receiving terminal and tilt receiving terminals, wherein the vertical receiving terminal is vertically corresponding to the optical signal emitting terminal, and the tilt receiving terminals are symmetrically distributed two sides of the vertical receiving terminal;

a second step, if there are a plurality of touch points on the display surface, the touch points being between the signal emitting units and the signal receiving units;

the touch points being generated by contact stuffs touching the display surface;

the optical signal emitting terminals emitting the optical signals in turn, and the corresponding vertical terminal also controlled to be in a receiving mode in turn, while other tilt terminals being in a non-receiving mode;

in the processing of the second step, if there is no touch point between the optical signal emitting terminal and the corresponding vertical terminal, the vertical terminal will receive the optical signals emitted by the optical signal emitting terminal, such that there is no touch point between the optical signal emitting terminal and the corresponding vertical terminal;

if there exists a touch point between the optical signal emitting terminal and the corresponding vertical terminal, the vertical terminal will not receive the optical signals emitted by the optical signal emitting terminal, such that that there exists a touch point between the optical signal emitting terminal and the corresponding vertical terminal;

by the above steps, a preliminary location area where the touch points located on the display surface being obtained;

in a third step, the preliminary location area obtained in the second step being corrected for the first time to obtain a maximum positive tilt angle correction area, the optical signal emitting terminals emitting the optical signals in turn, and the corresponding tilt terminal also controlled to be in the receiving mode in turn, wherein the tilt terminal is at one side of the vertical terminal and furthest away from the vertical receiving terminal;

in the processing of the third step, if there is no touch point between the optical signal emitting terminal and the corresponding tilt terminal, the tilt terminal will receive the optical signals emitted by the optical signal emitting terminal, such that there is no touch point between the optical signal emitting terminal and the corresponding tilt terminal;

if there exists a touch point between the optical signal emitting terminal and the corresponding tilt terminal, the tilt terminal will not receive the optical signals emitted by the optical signal emitting terminal, such that there exists a touch point between the optical signal emitting terminal and the corresponding tilt terminal;

by the above steps, the preliminary location area obtained in the second step being corrected and narrowed;

in a fourth step, the location area obtained in the third step being corrected for the second time to obtain a maximum negative tilt angle correction area;

the optical signal emitting terminals emitting the optical signals in turn, and the corresponding tilt terminal also controlled to be in the receiving mode in turn, wherein the tilt terminal is at the other side of the vertical terminal and furthest away from the vertical receiving terminal;

in the processing of the fourth step, if there is no touch point between the optical signal emitting terminal and the corresponding tilt terminal, the tilt terminal will receive the optical signals emitted by the optical signal emitting terminal, such that there is no touch point between the optical signal emitting terminal and the corresponding tilt terminal will be obtained;

if there exists a touch point between the optical signal emitting terminal and the corresponding tilt terminal, the tilt terminal will not receive the optical signals emitted by the optical signal emitting terminal, such that there exists a touch point between the optical signal emitting terminal and the corresponding tilt terminal;

by the above steps, the location area obtained in the third step being corrected and narrowed;

in a fifth step, the optical signal emitting terminals emitting the optical signals in turn, and the corresponding tilt terminal also controlled to be in the receiving mode in turn;

in the processing of the fifth step, the way of controlling the corresponding tilt terminal to be in the receiving mode in turn being performed according to the following sequence;

step A, at one side of the vertical receiving terminal, besides the tilt receiving terminal in the third step, other tilt receiving terminals being controlled to be receiving mode in turn, from the furthest to the nearest to the vertical receiving terminal;

step B, at the other side of the vertical receiving terminal, besides the tilt receiving terminal in the fourth step, other tilt receiving terminals being controlled to be in the receiving mode in turn, from the furthest to the nearest to the vertical receiving terminal;

the above step A and step B being performed repeatedly, and each repeat will obtain certain location area information;

the location area becoming smaller and smaller as the step A and step B repeat;

the maximum negative tilt angle correction area obtained in the fourth step being corrected and narrowed to obtain positions of a plurality of touch points;

in a sixth step, fake points being get rid of by filtering the positions of the touch points obtained in the fifth step;

the above filtering comprising firstly setting geometric area of standard touch points, secondly eliminating touch points whose areas are smaller than the geometric area of the standard touch points, and finally determining the result position of the touch points to finish the whole recognition process.

2. The method of claim 1, wherein the display surface is a touch screen of a digital product.

3. The method of claim 1, wherein the display surface is substantially rectangular, the optical signal emitting units are arranged at one horizontal edge and one vertical edge of the display surface, and the optical signal receiving units are arranged at the other horizontal edge and vertical edge of the display surface accordingly.

4. The method of claim 3, wherein when the display surface is substantially rectangular, the optical signal emitting terminals of the optical signal emitting unit along the horizontal edge of the display surface firstly emit the optical signals, and then the corresponding vertical receiving terminals of the optical signal receiving unit along the horizontal edge of the display surface receive the signals.

5. The method of claim 1, wherein emitting angle of the optical signal emitting terminal is no less than 30 degrees.

6. The method of claim 1, wherein in the process of repeating the step A and step B, the location area is optimized, and the number of optical signals emitting terminals emitting the optical signals is decreased step by step;

after the location area information is obtained by repeating the step A and step B, a top border is determined based on the top edge of the location area, a bottom border is determined based on the bottom edge of the location area, a left border is determined based on the left edge of the location area, a right border is determined based on the right edge of the location area;

the top border, bottom border, left border and right border together define on an optimized area, which is much smaller than the display surface, and the touch points are all located in the optimized area;

the optical signal emitting terminals without optical signals going through the optimized area stop work, only the optical signal emitting terminals having optical signals going through the optimized area keep working and repeat the step A and step B.

7. The method of claim 1, wherein the optical signals emitted by the optical signal emitting terminal are infrared rays.