[54] METHOD OF, AND APPARATUS FOR, DETECTING OPTICAL AXIS OF HEADLAMP
[75] Inventor: Osamu Takao, Hiroshima, Japan
[73] Assignee: Chuo Electronic Measurement Co., Ltd., Hiroshima, Japan
[21] Appl. No.: 177,050
[22] Filed: Jan. 4,1994
[51] Int. Cl.« G01M 11/06
[52] U.S. Q 356/121; 382/1
[58] Field of Search 356/121; 33/288
[56] References Cited
U.S. PATENT DOCUMENTS
4,609,939 9/1986 Kozawa 356/121
4,634,275 1/1987 Yoshida 356/121
FOREIGN PATENT DOCUMENTS 57-179639 11/1982 Japan .
180122 8/1986 Japan 356/121
Primary Examiner—Richard A. Rosenberger
Attorney, Agent, or Firm—Jordan and Hamburg
[57] ABSTRACT
In a method of detecting optical axis of a headlamp, according to the present invention, an image of the light projected onto the screen is segmented grid by grid on the reference grid plane, a test window set in the reference grid plane is moved and the illuminance of the light incident upon a CCD corresponding to each grid in a test window B set in the reference grid plane is integrated each time the test window B is moved, and the center of the test window C when the integrated illuminance reaches a maximum value is detected as the optical axis position. According to the present invention, it is possible to positively detect an headlamp optical axis even if a plurality of hot zones exists.
4 Claims, 8 Drawing Sheets
