Driver alert system
First Claim
1. Apparatus for warning the driver of a motor vehicle when the vehicle is about to drift across a line on a road surface having a width within a predetermined range of minimum and maximum widths indicative of a center line or an edge line, said apparatus comprising:
- a light source adapted to be carried by said vehicle adjacent a side thereof for directing light rays downwardly toward the road surface,a photoresponsive receiver adapted to be carried by said vehicle for receiving said light rays reflected from said surface,said receiver having photoelectric means for producing an output corresponding to reflected rays received at a plurality of points spaced horizontally transversely of the fore-and-aft axis of the vehicle, and means responsive to said output for producing an alarm-activating signal when said output is indicative of the reflection of said received rays from a line on said surface of at least said minimum width but no greater than said maximum width, andalarm means responsive to said activating signal for warning the driver, whereby to alert the driver to the detection of a center or edge line and discriminate against other markings of greater or lesser width.
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Accused Products
Abstract
A highway line detection system which is insensitive to changes in road surface warns the driver of a motor vehicle when the vehicle is about to drift across either a center line or an edge line. A unit on each side of the vehicle directs light rays rich in infrared and red radiation downwardly toward the road surface, and includes a photoresponsive receiver responsive to the rays reflected from a painted line or mark. A valid center line or edge line has a width within a predetermined range of minimum and maximum widths and is recognized by the receiver to activate a suitable alarm, but other markings of greater or lesser width are discriminated against to prevent a false alarm. The receiver employs a series of photoconductive cells which are highly sensitive to radiation in the red and near infrared region; they are spaced horizontally on a line extending orthogonally with respect to the fore-and-aft axis of the vehicle in order to establish corresponding spaced points at which reflected rays are detected. Logic circuitry responsive to the photocell outputs activates the alarm if the combination of responding photocells is indicative of the reflection of received rays from a line on the road surface of at least said minimum width but no greater than said maximum width.
97 Citations
15 Claims
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1. Apparatus for warning the driver of a motor vehicle when the vehicle is about to drift across a line on a road surface having a width within a predetermined range of minimum and maximum widths indicative of a center line or an edge line, said apparatus comprising:
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a light source adapted to be carried by said vehicle adjacent a side thereof for directing light rays downwardly toward the road surface, a photoresponsive receiver adapted to be carried by said vehicle for receiving said light rays reflected from said surface, said receiver having photoelectric means for producing an output corresponding to reflected rays received at a plurality of points spaced horizontally transversely of the fore-and-aft axis of the vehicle, and means responsive to said output for producing an alarm-activating signal when said output is indicative of the reflection of said received rays from a line on said surface of at least said minimum width but no greater than said maximum width, and alarm means responsive to said activating signal for warning the driver, whereby to alert the driver to the detection of a center or edge line and discriminate against other markings of greater or lesser width. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. Apparatus for warning the driver of a motor vehicle when the vehicle is about to drift across a line on a road surface having a width within a predetermined range of minimum and maximum widths indicative of a center line or an edge line, said apparatus comprising:
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a light source, photoresponsive means having first and second pairs of photoelectric devices, means for mounting said source on said vehicle adjacent a side thereof with said source disposed to direct light rays downwardly toward the road surface, and for mounting said photoresponsive means on said vehicle adjacent said source, said photoresponsive means including structure supporting said devices in respective positions for receiving said light rays reflected from said surface and detecting the same, said structure spacing said first pair of devices apart horizontally transversely of the fore-and-aft axis of the vehicle a first distance which establishes a first response window that can be spanned by said received rays reflected from a marking on said surface of at least said minimum width, and spacing said second pair of devices apart a second, greater transverse distance which establishes a second response window that can be spanned by said received rays reflected from a marking on said surface of greater width than said maximum width, alarm means for warning the driver, and control means connected with said devices and said alarm means for activating the latter when said received rays are detected by said first pair of devices but not by either of said devices of said second pair thereof, whereby to alert the driver to the detection of a center or edge line and discriminate against other markings of greater width.
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Specification