Vehicular automatic light control apparatus

• US 20060108932A1
• Filed: 08/15/2005
• Published: 05/25/2006
• Est. Priority Date: 08/25/2004
• Status: Active Grant

• Current Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Original Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Inventors: Asakura, Masahiko, Yamazaki, Masayuki
• Granted Patent: US 7,378,753 B2
• Time in Patent Office: Days
• US Class Current: 315/82
• CPC Class Codes: B60Q 1/143 combined with another condition, e.g. using vehicle recognition from camera images or activation of wipers
• CPC Class Codes: B60Q 2300/052 Switching delay, i.e. the beam is not switched or changed instantaneously upon occurrence of a condition change
• CPC Class Codes: B60Q 2300/312 Adverse weather
• CPC Class Codes: B60Q 2300/314 Ambient light
• CPC Class Codes: B60Q 2300/337 Tunnels or bridges

Abstract

A headlight is turned on if an external illuminance value outside of the vehicle is equal to or lower than a first threshold value if the non-rainfall state is judged from windshield wiper activation, and is permitted to be turned on if the external illuminance value is equal to or lower than a second threshold value higher than the first predetermined illuminance value if the rainfall state is judged. When the vehicle is capable of being driven and the headlight is turned on, if an average illuminance value of the external illuminance value is equal to or higher than a predetermined value, then the second threshold value switches to the first threshold value. When the headlight is turned off, if the activation of the wiper has not been confirmed for a first predetermined period, then the second threshold value switches to the first threshold value.

Claims

1. A vehicular automatic light control apparatus for judging a non-rainfall state or a rainfall state based on information about wiping operation of a windshield wiper of a vehicle, turning on a headlight if an external illuminance value outside of the vehicle is equal to or lower than a first predetermined illuminance value as a first threshold value if the non-rainfall state is judged, and permitting the headlight to be turned on if the external illuminance value is equal to or lower than a second predetermined illuminance value as a second threshold value higher than said first predetermined illuminance value if the rainfall state is judged, comprising:

average illuminance value calculating means for determining an average illuminance value of the external illuminance value in each predetermined period when the vehicle is capable of being driven; and

switching means for switching from the second threshold value to the first threshold value under different conditions based on whether the headlight is turned on or off;

wherein said switching means switches from the second threshold value to the first threshold value under such a condition that the determined average illuminance value is equal to or greater than a predetermined value when the headlight is turned on, and switches from the second threshold value to the first threshold value under such a condition that the wiping operation of the wiper has not been confirmed for a first predetermined period when the headlight is turned off.

2. A vehicular automatic light control apparatus according to claim 1, further comprising:

tunnel detecting means for detecting when the vehicle is passing through a tunnel;

wherein said switching means switches from the second threshold value to the first threshold value under such a condition that the wiping operation of the wiper has not been confirmed for a second predetermined period and the vehicle is passing through a tunnel as detected by said tunnel detecting means when the headlight is turned on and the determined average illuminance value is less than the predetermined value.

3. A vehicular automatic light control apparatus according to claim 2, wherein said tunnel detecting means detects when the vehicle is passing through a tunnel by detecting a predetermined external illuminance value in each predetermined period.