Abstract: The structure of the present invention majorly includes: an outer shell body; at least one connection portion; and an optical projection system set inside the outer shell body. The optical projection system includes: an imaging unit; a reflector; a reflective curved mirror; and at least one optical lens; wherein the imaging unit projects the predefined image and incidents on the reflective curved mirror after being reflected by the reflector to adjust the imaging path and correct the aberration. And, the optical lens will magnify the predefined image in the imaging path to make the predefined image reflected to the user's eyes through the windshield to form the virtual image of the predefined image refracted outside the windshield. The present invention can realize the triangle imaging principle in a smaller space, enlarge the imaging range, reduce the aberration problem, and simply set outside the dashboard through the outer shell body.