Touch display panel and method for driving the same, and display device

A method for driving a touch display panel, the touch display panel comprising:

• a liquid crystal layer;
• and a detection layer for light-intensity, which is located at a light exiting side of the liquid crystal layer and is configured to detect an intensity of light passing through the liquid crystal layer at a region thereof corresponding to a touch position on the touch display panel, in both conditions that the touch position on the touch display panel is touched and not touched by a touch action, wherein the detection layer for light-intensity comprises a plurality of detectors which are arranged in an array, and the touch display panel further comprises a black matrix and a signal wiring which is arranged to be connected with the plurality of detectors, wherein orthographic projections of the plurality of detectors and the signal wiring on the liquid crystal layer are located within a orthographic projection of the black matrix on the liquid crystal layer, the method comprising:
• detecting the intensity of light passing through the liquid crystal layer at the region thereof corresponding to the touch position on the touch display panel in a condition that the touch position on the touch display panel is touched by the touch action, by the detection layer for light-intensity;
• and
• determining touch information by comparing the intensity of light passing through the liquid crystal layer in the condition that the touch position on the touch display panel is touched, with an intensity of light passing through the liquid crystal layer in a condition that the touch position on the touch display panel is not touched.