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A driver's night view assistance system has been put into practical use. The night view assistance system helps drivers to see farther down the road than low beam headlamps by illuminating the road scene with an infrared projector. We have developed an infrared projector by using a projector type headlamp. Infrared is produced by shielding visible light at a multiple-layer film of Silicon (Si) and Silicon Dioxide (SiO2) which is deposited alternately on a condenser lens surface. The principle of the multiple-layer film and the infrared projector's structure are reported in this paper.

While driving his motor vehicle, the driver constantly looks at the lane marking to help with his or her coursing. The conspicuity of lane markings depends greatly on its retroreflection and that of the surrounding road surface area. In this study, we measured in a darkroom the retroreflection performances of two types of pavement surfaces and also two types of lane marking, all of which are types currently in practical use. The following conclusions were reached as a result: 1. The reflection characteristics of lane marking Compared to conventional type lane marking, high-luminance type lane marking exhibits a reflection characteristic that is approximately 3 and 5 times greater under dry and wet road conditions, respectively. 2. The reflection characteristics of road surfaces From the initial time of paving, the luminance factor of a dense asphalt road surface rises roughly 5-to 6-folds with the passage of time. Thus, the whiteness of road surfaces increases with time.

Although we have measured the luminance of visual circumstances like road surface, lane-mark, traffic sign, etc., by using luminance meters. It took us a lot of operating time to grasp spread of all visual circumstances. Under the circumstances varied with the time such as fog, rain and so on, it is impossible to measure at many points on a definite condition. In this report, we would present our development of the new system and its real application to visual circumstances, in which a lot of brilliance can be measured at the same time by the transaction of portrait of digital still camera.

In recent years, traffic fatalities in Japan have consistently numbered in excess of 10,000, making them a serious social issue. Among these deaths resulting from traffic accidents, fatal accidents occurring at night outnumber daytime fatalities by three to one; when conditions are rainy, this figure increases to ten to one. These facts point to the importance of the role of automobile forward lighting systems. In order to provide enhanced nighttime safety measures, we have been working since 1990 on the development of a headlamp system that can control and adjust the headlamp beam in response to driving conditions. In this report, we will outline the general features, functions and lighting performance of forward lighting systems, focusing on this newly developed headlamp system.

These headlighting systems control the headlamp beams according to the running state of a vehicle at night in order to provide optimal illumination. They have two functions: to control the range of illumination according to vehicle speed and to control beam direction in response to the steering. Two optical systems were developed to realize these functions. One system uses two movable mirrors in each headlamp, while the other system uses a movable lens installed in front of the projector lamp. According to photometric data analysis done in our laboratory, bath systems improve visibility on curved roads substantially. It was also found that they are effective in limiting glare projected onto oncoming vehicles.

The induction swirl in a spark ignition engine was studied. An effective model test using water was devised which allowed observation of the induction swirl in the cylinder. First, steady flow without a piston was observed, and it was discovered that two vortexes were generated in the cylinder. Next, the flow patterns of several cylinder heads with intake ports of various shapes were observed and their relation to combustion was investigated. From the results, it was discovered that high speed and well mixed vortexes aided combustion. Experimentation with unsteady flow with a piston was also conducted.