METHOD FOR IMPROVING THE IMAGE QUALITY OF A HUD SYSTEM, A POLARIZING ELEMENT, AND A HUD SYSTEM COMPRISING SUCH A POLARIZING ELEMENT

摘要

The present invention relates to a method for improving the image quality of a HUD system, the HUD system comprising an image display device (1) and a reflecting element (3) having a partially transmissive first reflective surface (3a) and at least one partially transmissive second reflective surface (3b) substantially parallel thereto, and a polarization-dependent reflection layer (13) and/or an anti- reflection layer (14) and/or an optical birefringent layer (15), wherein the second reflective surface (3b) is arranged on the side of the first reflective surface (3a) opposite the image display device (1) and wherein the reflecting element (3) is adapted to produce reflected light beams (12a, 12b) from incident light beams (11) which are originating from the points of the image generated by the image display device (1) and arriving at the reflective surfaces (3a, 3b) and to reflect a portion of the reflected light beams (12a, 12b) toward a design detection point (23a), characterized by - determining for each of the incident light beams (11) reflected by the reflecting element (3) in the direction of the design detection point (23a) an optimal polarization state to which the intensity ratio of the reflected light beams (12a, 12b) reflected by the first reflective surface (3a) and first reflected by the second reflective surface (3b) during the reflection of the given incident light beam (11) is minimal, and - setting the polarization states of the incident light beams (11) reflected by the reflecting element (3) in the direction of the design detection point (23a) by means of a polarizing element (20) arranged in the path of the incident light beams (11) in accordance with the previously determined optimal polarization states. The invention also relates to a polarizing element and a HUD system.