Multi-touch positioning method and multi-touch screen

A multi-touch screen, comprising a display panel, a first infrared ray generator set at a first angle of the display panel, a second infrared ray generator set at a second angle of the display panel, a first infrared ray image sensor set at an opposite angle of the first angle, a second infrared ray image sensor set at an opposite angle of the second angle, and a control processing sub-system connected to the display panel, wherein

• the display panel is used to receive touch events;
• the first infrared ray generator is used to emit infrared rays at a first wavelength;
• the second infrared ray generator is used to emit infrared rays at a second wavelength;
• the first infrared ray image sensor is used to receive the infrared rays emitted by the first infrared ray generator at the first wavelength and to generate a first infrared ray image;
• the second infrared ray image sensor is used to receive the infrared rays emitted by the second infrared ray generator at the second wavelength and to generate a second infrared ray image;
• and
• the control processing sub-system is used to perform processing for the first infrared ray image generated by the first infrared ray image sensor and the second infrared ray image generated by the second infrared ray image sensor, to determine at least one touch point,
• a touch point position recognition processing sub-system for performing touch point position recognition processing for the first infrared ray image generated by the first infrared ray image sensor and the second infrared ray image generated by the second infrared ray image sensor,
• wherein the touch point position recognition processing sub-system comprises:
• a microprocessor for driving the first infrared ray generator set at the first angle of the display panel to emit infrared rays at the first wavelength, driving the second infrared ray generator set at the second angle of the display panel to emit infrared rays at the second wavelength, driving the first infrared ray image sensor to receive the infrared rays of the first wavelength and generate the first infrared ray image, and driving the second infrared ray image sensor to receive the infrared rays of the second wavelength and generate the second infrared ray image;
• a selection control circuit for performing image correction processing for the first infrared ray image and the second infrared ray image, respectively;
• an analog to digital converter for performing analog to digital conversion for the first infrared ray image and the second infrared ray image subjected to the image correction processing, to generate a first digital image and a second digital image;
• a digital signal processor for performing discrimination processing for the first digital image and the second digital image, to obtain position information of the touch point;
• and
• memory for storing the position information of the touch point obtained by the digital signal processor,
• wherein the digital signal processor comprises:
• a projection processing module for performing the discrimination processing for the first digital image and the second digital image, to obtain a first projection position in the first digital image of the touch point and a second projection position in the second digital image of the touch point;
• a marking position generation module for generating a first marking position on a second diagonal according to the first projection position, and generating a second marking position on a first diagonal according to the second projection position, wherein the first diagonal is a connecting line between a vertex of the first angle and a vertex of the opposite angle of the first angle, and the second diagonal is a connecting line between a vertex of the second angle and a vertex of the opposite angle of the second angle;
• a linear function generation module for generating a first linear function according to a position of the vertex of the opposite angle of the first angle and the first marking position, and generating a second linear function according to a position of the vertex of the opposite angle of the second angle and the second marking position;
• and
• a coordinate generation module for obtaining coordinates of the touch point according to the first linear function and the second linear function.

A multi-touch screen, comprising a display panel, a first infrared ray generator set at a first angle of the display panel, a second infrared ray generator set at a second angle of the display panel, a first infrared ray image sensor set at an opposite angle of the first angle, a second infrared ray image sensor set at an opposite angle of the second angle, a third infrared ray generator set at a third angle of the display panel, a fourth infrared ray generator set at a fourth angle of the display panel, a third infrared ray image sensor set at an opposite angle of the third angle, and a fourth infrared ray image sensor set at an opposite angle of the fourth angle, and a control processing sub-system connected to the display panel, wherein

• the display panel is used to receive touch events;
• the first infrared ray generator is used to emit infrared rays at a first wavelength;
• the second infrared ray generator is used to emit infrared rays at a second wavelength;
• the third infrared ray generator is used to emit infrared rays at a third wavelength;
• the fourth infrared ray generator is used to emit infrared rays at a fourth wavelength;
• the first infrared ray image sensor is used to receive the infrared rays emitted by the first infrared ray generator at the first wavelength and to generate a first infrared ray image;
• the second infrared ray image sensor is used to receive the infrared rays emitted by the second infrared ray generator at the second wavelength and to generate a second infrared ray image;
• the third infrared ray image sensor is used to receive the infrared rays emitted by the third infrared ray generator at the third wavelength and to generate a third infrared ray image;
• the fourth infrared ray image sensor is used to receive the infrared rays emitted by the fourth infrared ray generator at the fourth wavelength and to generate a fourth infrared ray image;
• and
• the control processing sub-system is used to perform processing for the first infrared ray image generated by the first infrared ray image sensor, the second infrared ray image generated by the second infrared ray image sensor, the third infrared ray image generated by the third infrared ray image sensor, and the fourth infrared ray image generated by the fourth infrared ray image sensor, to determine at least one touch point,
• the selection control circuit is further used to perform image correction processing for the first infrared ray image, the second infrared ray image, the third infrared ray image and the fourth infrared ray image, respectively;
• the analog to digital converter is further used to perform analog to digital conversion for the first infrared ray image, the second infrared ray image, the third infrared ray image and the fourth infrared ray image subjected to the image correction processing, to generate a third digital image and a fourth digital image;
• and
• the digital signal processor is further used to perform the discrimination processing for the first infrared ray image, the second infrared ray image, the third digital image and the fourth digital image, to obtain position information of the touch point,
• the projection processing module is further used to perform the discrimination processing for the first infrared ray image, the second infrared ray image, the third digital image and the fourth digital image to obtain a first projection position in the first digital image of the touch point, a second projection position in the second digital image of the touch point, a third projection position in the third digital image of the touch point and a fourth projection position in the fourth digital image of the touch point;
• the marking position generation module is further used to generate a first marking position on a second diagonal according to the first projection position, generate a second marking position on a first diagonal according to the second projection position, generate a third marking position on the second diagonal according to the third projection position, and generate a fourth marking position on the first diagonal according to the fourth projection position, wherein the first diagonal is a connecting line between a vertex of the first angle and a vertex of the opposite angle of the first angle, and the second diagonal is a connecting line between a vertex of the second angle and a vertex of the opposite angle of the second angle;
• the linear function generation module is further used to generate a first linear function according to a position of the vertex of the opposite angle of the first angle and the first marking position, generate a second linear function according to a position of the vertex of the opposite angle of the second angle and the second marking position, generate a third linear function according to a position of the vertex of the opposite angle of the third angle and the third marking position, and generate a fourth linear function according to a position of the vertex of the opposite angle of the fourth angle and the fourth marking position;
• and
• the coordinate generation module is further used to obtain coordinates of the touch point according to the first linear function, the second linear function, the third linear function and the fourth linear function.