Headlamp control device and vehicle headlamp having headlamp control device

• US 8,425,092 B2
• Filed: 08/27/2009
• Issued: 04/23/2013
• Est. Priority Date: 08/28/2008
• Status: Active Grant

• Current Assignee: Koito Manufacturing Company Limited
• Original Assignee: Koito Manufacturing Company Limited
• Inventors: Kobayashi, Shoji
• Primary Examiner(s): Makiya, David J
• Application Number:
  US12/548,768
• Publication Number:
  US 20100052550A1
• Time in Patent Office: 1,335 Days
• Field of Search: 362/466, 362/465, 362/525
• US Class Current: 362/466
• 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 2300/054 Variable non-standard intensity, i.e. emission of various beam intensities different from standard intensities, e.g. continuous or stepped transitions of intensity
• CPC Class Codes: B60Q 2300/332 on city roads
• CPC Class Codes: B60Q 2300/3321 Detection of streetlights
• CPC Class Codes: B60Q 2300/333 on suburban or country roads
• CPC Class Codes: B60Q 2300/337 Tunnels or bridges
• CPC Class Codes: B60Q 2300/42 oncoming vehicle
• CPC Class Codes: B60Q 2300/45 Special conditions, e.g. pedestrians, road signs or potential dangers

Abstract

A headlamp control device is provided. The device includes a visual object luminance unit, an adapted state unit, a recognition limit unit, a visual object recognition unit, and a light distribution control unit. The visual object luminance unit estimates a visual object luminance based on information about a vehicle forward captured image. The adapted state unit estimates an adaptation luminance based on the information about the vehicle forward captured image. The recognition limit unit estimates a recognition limit luminance, in the visual object range, based on at least the adaptation luminance. The visual object recognition unit determines whether the visual object luminance is less than the recognition limit luminance. The light distribution control unit controls a light distribution of a headlamp unit such that the visual object luminance is included in a range of the recognition limit luminance, if the visual object luminance is less than the recognition limit luminance.

Claims

1. A headlamp control device comprising:

a visual object luminance estimating unit which estimates a visual object luminance based on information about a captured image of an area in front of a vehicle;

an adapted state estimating unit which estimates an adaptation luminance of a driver of the vehicle based on the information about the captured image, wherein the adaptation luminance is held at a recovery state for a time period after a peak visual object luminance is estimated, the recovery state being a higher luminance than a luminance based solely on the visual object luminance;

a recognition limit estimating unit which estimates a recognition limit luminance of the driver based on at least the adaptation luminance, wherein the recognition limit luminance represents a luminance in which the driver can recognize an object in the area in front of the vehicle;

a visual object recognition determining unit which determines whether the visual object luminance is less than the recognition limit luminance; and

a light distribution control unit which controls a light distribution of a headlamp unit provided in a vehicle such that the visual object luminance is included in a range of the recognition limit luminance, if the visual object luminance is less than the recognition limit luminance.

2. A headlamp control device comprising:

a visual object luminance estimating unit which estimates a visual object luminance which is luminance in a driver'"'"'s visual object range, based on information about a vehicle forward captured image, wherein the visual object luminance represents a luminance of an object in front of the vehicle in the driver'"'"'s visual object range;

an adapted state estimating unit which estimates a driver'"'"'s adaptation luminance of the driver based on the information about the vehicle forward captured image, wherein the adaptation luminance is held at a recovery state for a time period after a peak visual object luminance is estimated, the recovery state being a higher luminance than a luminance based solely on the visual object luminance;

a recognition limit estimating unit which estimates a recognition limit luminance of the driver based on at least the adaptation luminance, wherein the recognition limit luminance represents a luminance in which the driver can recognize the object;

a visual object recognition determining unit which determines whether the visual object luminance is less than the recognition limit luminance; and

a light distribution control unit which controls a light distribution of a headlamp unit provided in a vehicle such that the visual object luminance is included in a range of the recognition limit luminance, if the visual object luminance is less than the recognition limit luminance.

3. The headlamp control device according to claim 2,

wherein the light distribution control unit controls the light distribution so as to counteract a decrease in an amount of the adaptation luminance, if the adaptation luminance decreases.

4. The headlamp control device according to claim 2,

wherein the light distribution control unit controls the light distribution so as to increase a luminance of the visual object range in accordance with an increase in an amount of the adaptation luminance, if the adaptation luminance increases.

5. The headlamp control device according to claim 2

wherein the adapted state estimating unit estimates the adaptation luminance based on information about at least a main track range of the vehicle forward captured image.

6. The headlamp control device according to claim 2,

wherein the adapted state estimating unit estimates the adaptation luminance based on information about an area including a high-luminance light source, if the high-luminance light source is included in the vehicle forward captured image.

7. A vehicle headlamp comprising:

a headlamp unit which generates a light distribution; and

a headlamp control device comprising;

a visual object luminance estimating unit which estimates a visual object luminance which is luminance in a driver'"'"'s visual object range, based on information about a vehicle forward captured image, wherein the visual object luminance represents a luminance of an object in front of the vehicle in the driver'"'"'s visual object range;

an adapted state estimating unit which estimates a driver'"'"'s adaptation luminance based on the information about the vehicle forward captured image, wherein the adaptation luminance is held at a recovery state for a time period after a peak visual object luminance is estimated, the recovery state being a higher luminance than a luminance based solely on the visual object luminance;

a recognition limit estimating unit which estimates a recognition limit luminance of the driver based on at least the adaptation luminance wherein the recognition limit luminance represents a luminance in which the driver can recognize the object;

a visual object recognition determining unit which determines whether the visual object luminance is less than the recognition limit luminance; and

a light distribution control unit which controls the light distribution of the headlamp unit such that the visual object luminance is included in a range of the recognition limit luminance, if the visual object luminance is less than the recognition limit luminance.