An optical imaging device includes a display panel whereon a coordinate detecting area is formed, at least one first reflective optical unit installed on an outside corner of the display panel for reflecting light transmitted from an object moving within the coordinate detecting area, at least one second reflective optical unit installed outside the display panel for reflecting the light reflected from the at least one first reflective optical unit, an image capturing module for capturing the light reflected from the at least one second reflective optical unit so as to capture image of the object, and a control module coupled to the image capturing module for receiving the image captured by the image capturing module and for calculating a coordinate value of the object within the coordinate area according to the image.