Headlight aiming method using pattern framing

Abstract

A method for aiming vehicle headlights and for visually displaying the illumination patterns of the headlights using 'pattern framing'. The apparatus focuses the light beam on a screen and senses the intensity of the light in each cell of a matrix of cells overlying the reflected light beam with an image sensor. The apparatus generates an electrical signal for each cell indicative of the intensity of the light beam in each cell. The apparatus includes a computer for comparing at least some of the electrical signals to each other and with established criteria to determine whether the headlight is aimed within a prescribed degree of accuracy. The matrix is searched to find a row and column of points farthest away from the 'hot spot' of the beam which have at least one point with a certain light intensity relationship. The row and column are compared with the established criteria to determine if the headlight is properly aimed. The apparatus describes the illumination pattern of a headlight by visually displaying at least some of the electrical signals, i.e., the light intensities and their locations, on a display. The illumination pattern can be displayed as a series of isocandela lines, or can be displayed as a simulated headlight illumination pattern on a simulated road surface. The headlight illumination pattern can be compared to a properly aimed, simulated headlight illumination pattern to indicate the necessary aiming correction.