Headlight optical axis adjustment device

Abstract

The present invention aims to perform optical axis adjustment while a vehicle is stopped only in necessary situations and to avoid unnecessary adjustment, and to further enhance durability. A headlight optical axis adjustment device for adjusting an optical axis of a headlight based on a pitch angle of the vehicle includes an opened / closed state detection section for detecting an open / closed state of an open / close unit where the opened state is when a passenger gets on / out or when a baggage is being loaded / unloaded to and from the vehicle; and an optical axis adjustment permitting section for permitting optical axis adjustment of the headlight based on the pitch angle of the vehicle when the opened state of the open / close unit is detected by the opened / closed state detection section.

Description

PRIOR APPLICATIONS[0001]This application is a divisional of and claims the benefit of co-pending U.S. patent application Ser. No. 12 / 241,315, filed on Sep. 30, 2008, titled “Headlight Optical Axis Adjustment Device”, and is incorporated herein by reference.BACKGROUND OF THE INVENTION[0002]1. Technical Field[0003]The present invention relates to a headlight optical axis adjustment device also referred to as “auto levelizer” used in vehicles such as an automobile.[0004]2. Related Art[0005]According to provision of safety standard (Department of Transportation Law No. 67, Jul. 28, 1951) of Road Trucking Vehicle Law, vehicles such as automobiles (hereinafter referred to as a vehicle) must be provided with a “running headlight” (so-called high beam) and a “passing headlight” (so-called low beam), or a “light distribution variable headlight” which is a combination of the above (combination of high beam and low beam).[0006]The “running headlight” is provided to check obstructions in terms ...

AI Technical Summary

Benefits of technology

This solution reduces the frequency of unnecessary adjustments, enhancing the durability of the optical axis adjustment actuator by ensuring adjustments are only made when necessary, thus preventing actuator wear and maintaining effective light distribution.

Problems solved by technology

If a number of passengers or an amount of load of the vehicle are changed even if the cutoff line is appropriately set as above, the cutoff line moves to the upper side, which may dazzle the drivers of oncoming vehicles and the like.

However, the pitch angle of the vehicle finely fluctuates not only when the number of passengers or the amount of load are changed, but also when the passengers goes in / out or when the baggage is being loaded / unloaded to and from the vehicle, and also fluctuates when accelerating or decelerating during traveling or riding over bumps of the road surface.

Thus, an optical axis adjustment mechanism of the headlight operates every time the pitch angle changes if the device simply “tilts and adjusts the optical axis of the headlight in a direction of canceling the pitch angle of the vehicle”, and thus operation frequency of actuators such as a motor arranged in the mechanism increases thereby inhibiting durability.

In other words, in the first conventional art, a tilt adjustment of an optical axis of a headlight based on a pitch angle of a vehicle is performed once while the vehicle is stopped and the tilt adjustment is performed for every predetermined interval while the vehicle remains stopped, but at least one tilt adjustment and the tilt adjustment of every interval are performed even in a stable state where the passenger does not go in / out and the baggage is not being loaded / unloaded, and thus the adjustments are waste, and improvement is desired in terms of further enhancing the durability.

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