| 主权项 |
1. An optical touch screen comprising:
a main body configured to enclose edges of a touch area of a screen; fine coordinate infrared light source generators configured to be arranged on each of two horizontal sides and two longitudinal sides of the main body and facing toward the touch area so as to generate a plurality of infrared light sources forming fine coordinates at a predefined spacing and to provide references for coordinates in a horizontal axis and a vertical axis of the touch area; two or more infrared cameras configured to be installed in the main body to detect the infrared light sources forming fine coordinates generated by the fine coordinate infrared light source generators; and a control unit configured to calculate coordinates of an object being touched in the touch area on the basis of detection data obtained by the infrared cameras, wherein: the control unit comprises:
a memory configured to store a lookup table having position numbers as index values, which are assigned to all infrared light sources forming fine coordinates, and angles of positions of the infrared light sources forming fine coordinates as table values, which are measured by the three infrared cameras, and store address maps that are generated by matching identification numbers assigned to addresses of pixels on image sensors of each of the infrared cameras with the position numbers wherein the pixels are exposed to light by the infrared light sources forming fine coordinates anda calculating unit configured to periodically check the pixels on the address maps that correspond to the identification numbers for light exposure data, and if there are pixels that stop being exposed to light, read the position numbers of corresponding infrared light sources forming fine coordinates from the address maps by use of the identification numbers assigned to the addresses of the pixels, obtain the angle values of the corresponding infrared light sources forming fine coordinates from the lookup table and calculate the coordinates of the touching object based on the obtained angle value. |
