Optical touch detection module, projection system with optical touch detection module, and method of optical touch detection module

A projection system comprising:

• a projection screen;
• a projection device configured for projecting an image to the projection screen;
• and
• a touch module located on the projection screen, the touch module comprising:
• a laser scanner device sequentially providing a projection region on the projection screen with a laser beam at a plurality of angles in a first period;
• a photodiode configured for receiving a first reflection beam from a touch point in the projection region, wherein the laser beam irradiates the touch point to result in reflection to generate the first reflection beam;
• an image capturing device capturing an image having a second reflection beam from the touch point in a second period, wherein the laser beam irradiates the touch point to result in reflection to generate the second reflection beam;
• and
• a processing unit electrically connected to the laser scanner device, the photodiode, and the image capturing device, the processing unit determining a first angle corresponding to the touch point according to the first reflection beam from the touch point received by the photodiode, determining a second angle corresponding to the second reflection beam according to the image having the second reflection beam captured by the image capturing device, and calculating location information of the touch point according to the first angle and the corresponding second angle.

A touch method of a touch module, comprising:

• sequentially providing a touch region with a laser beam at a plurality of angles in a first period by a laser scanner device;
• receiving a first reflection beam from a touch point in the touch region by a photodiode, wherein the laser beam irradiates the touch point to result in reflection to generate the first reflection beam;
• capturing an image having a second reflection beam from the touch point in a second period by an image capturing device, wherein the laser beam irradiates the touch point to result in reflection to generate the second reflection beam;
• and
• determining a first angle corresponding to the touch point by a processing unit according to the first reflection beam from the touch point received by the photodiode, determining a second angle corresponding to the second reflection beam by the processing unit according to the image having the second reflection beam captured by the image capturing device, and calculating location information of the touch point by the processing unit according to the first angle and the corresponding second angle.