| 摘要 |
<p>A compact, inexpensive and mass-producible optical display system for an automobile creates a highly visible and sharp, high contrast and pleasing, multi-color magnified virtual image of a primary instrument cluster at a viewing distance which is greater than the actual optical distance between the dashboard and the driver's eyes in order to enhance instrument readability, minimize driver eye strain, and reduce eye focus problems which are associated with transitioning between the far range viewing used for watching the road ahead and the near range viewing used for glancing at the instruments. A non-pupil forming display system uses a single off-axis aspherical mirror with power to create a virtual image of a miniaturized, multi-color passive image source, such as a segmented LCD panel, which is backlighted by a small filament incandescent light bulb. The aspheric surface is optimized to minimize aberrations and reduce vertical disparity and field curvature. The image source is pre-distorted to compensate for distortion in the off-axis configuration. A holographic diffusing screen element laminated onto the image source provides uniform high brightness and uniform contrast over the entire field-of-view which is visible from an eyellipse sufficient to accomodate most of the driver population, minimizes the visual impact of any optical aberrations near the edge of the viewing area, and provides the non-pupil forming system with some of the desirable optical properties of a pupil forming system.</p> |
