Another industry-academic cooperation managed by the Ministry of Technology is probably shaping our future. Chen Cheng-huan, Associate Professor at the Dept. of Photonics and Display Institute said the head-up display (HUD) has been considered as the most potential human visual interface for vehicles. There have been successful products on the road, and more and more regulation for safety concern will push the development and application of HUD even faster.

Chen Cheng-huan estimated, “HUD should be able meet the requirement of different scenario in driving.”

Besides the efficiency and the form factor issues, which are the major concerns from hardware viewpoint, one human factor issues unique for vehicle display becomes gaining wide attention when the HUD is put into practice on the road, which is the HUD image distance from the windshield.

“Accommodation is the major human factor concern in determining the required image position of HUD. It is normally argued that the HUD image should be at far distance enough so that the driver needs not to accommodate hard between HUD image and front scene.” Chen Cheng-huan said.

This requirement brings together with the issues of volume of HUD unit and apparent image size from HUD. The image distance can be increased by locating the HUD unit further away from the windshield. However, this will normally consume the space in dashboard. The consumed space can be reduced by optical means or folding light path, but with limited improvement.

Market survey also shows the diversity of habit in using HUD. For example, in high speed driving on the highway, the driver looks at far distance and the required information is normally simple, such as speed or some warning message. Image at far distance is essential, and required image size might not be that large. A dual mode HUD which allows the driver to choose far or close distance display mode has been proposed and established.