Light source detection and categorization system for automatic vehicle exterior light control and method of manufacturing

Abstract

In at least one embodiment, optical systems include a lens system assembly, a spectral filter material and a pixel array configured such that small, distant light sources can be reliably detected. In at least one embodiment, the optical systems provide accurate measurement of the brightness of the detected light sources and identification of the peak wavelength and dominant wavelength of the detected light sources. In at least one embodiment, the optical systems provide improved ability to distinguish headlights of oncoming vehicles and taillights of leading vehicles from one another, as well as from other light sources.

Description

CROSS-REFERENCE TO RELATED APPLICATION [0001] This application is a continuation of U.S. patent application Ser. No. 10 / 208,142, filed on Jul. 30, 2002, the entire disclosure of which is incorporated herein by reference.BACKGROUND OF THE INVENTION [0002] The present invention relates to automatic vehicle exterior light control systems. More specifically, the present invention relates to light source detection and categorization systems for use with automatic vehicle exterior light control. [0003] Automatic exterior light control systems for vehicles have been developed that utilize various light sensors and, or, an array of sensors (commonly referred to as an array of “pixels” or “pixel arrays”) to control the state of external lights of a controlled vehicle. These systems may, for example, be employed to detect the headlights of oncoming vehicles and the taillights of leading vehicles and to dim, or switch, the high beam headlights of a controlled vehicle off when headlights or tai...

AI Technical Summary

Benefits of technology

[0015] In yet another embodiment of the present invention, spectral filtering material is incorporated into the optical system such that light rays in various spectral bands can be accurately categorized by color. Thereby, for example, red light sources can be distinguished from white light sources. Particular embodiments of the present invention are capable of discerning amongst light sources throughout the visible spectrum. In yet other embodiments, ultra-violet and infrared light rays are filtered and prevented from being projected onto the sensor or pixel array. Preferably, the spectral filter material is a pigment, as opposed to a dye.

[0017] In one embodiment of the present invention, various external vehicle lights are used, such as high intensity discharge (HID), tungsten-halogen and blue enhanced halogen, to provide greater ability to distinguish reflections from various roadside reflectors and signs from headlights of oncoming vehicles and taillights of leading vehicles. Particular spectral filter material is employed in combination with the external vehicle lights to produce desired results.

[0019] In another embodiment of the manufacturing method of the present invention, a precision transfer molding apparatus is employed to transfer mold a lens system assembly proximate the pixel array. Molding the lens system assembly and the encapsulate block in one step simplifies the manufacturing method and results in lower cost.

[0020] In yet another embodiment of the manufacturing method of the present invention, a precision transfer molding apparatus is employed to transfer mold an encapsulate block with a precision lens system assembly mounting structure. A lens system assembly is provided with a mating mounting structure such that the lens system assembly can be “snap” fit into place. This manufacturing method provides for ease in lens system assembly replacement.

Problems solved by technology

In known automatic vehicle exterior light control systems, the associated small size of projected, distant, light sources severely impairs the ability of the system to accurately determine the color and brightness of the corresponding light source.

This is due largely to the fact that known sensors, and individual sensors of known pixel arrays, have a non-uniform response; depending upon the region of the pixel where light is incident, the sensitivity of the pixel will vary.

Pixel non-uniformity becomes especially problematic when attempting to determine the color and brightness of small, distant light sources.

When the light sources are small, distant sources, minor misalignment of the first lens system relative to the second lens system can cause significant error in the relative color measurement.

The distant light source projected by the red spectral filtering lens system may be incident onto a sensitive region of a pixel, while the light source may be projected onto an insensitive region by the second lens system, causing an erroneously high redness value.

Consequently, distant taillight detection of known systems is less than satisfactory in certain scenarios.

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