Method of and apparatus for examining automotive headlamp
First Claim
1. A method of examining an alignment of headlamp beam of an automobile in which a first mark representing a position of a headlamp beam axis and a second mark representing an allowable range for the headlamp beam axis are displayed on a monitor TV and when said first mark falls within said allowable range, a judgement is made that the alignment of the beam axis is acceptable, comprising the steps of:
- taking up by a TV camera an image of a light distribution pattern of a headlamp beam on a screen;
specifying a closed curved area surrounded by a line indicative of illumination intensity higher than a predetermined level in the taken-up image of the light distribution pattern;
determining a position of a geometrical center of the specified closed curved area to display the position of the geometrical center on the monitor TV;
measuring an area of the specified closed curved area;
comparing the measured actual area of said specified closed curved area with a command area; and
adjusting a quantity of light received by said TV camera in accordance with the result of the comparison until the measured actual area of said closed curved area becomes equal to said command area.
1 Assignment
0 Petitions
Accused Products
Abstract
A method of examining the state of alignment of headlamp beam axis has the following steps: taking up by a TV camera the image of the light distribution pattern of a headlamp beam on a screen; specifying a closed curved area of illumination intensities higher than a predetermined level in the taken-up image of the light distribution pattern; determining the position of the geometrical center of the specified closed curved area and displaying the position of the geometrical center on a monitor TV; measuring the area of the specified closed curved area; comparing the measured actual area of the closed curved area with a command area; adjusting the quantity of light received by the TV camera in accordance with the result of the comparison until the measured actual area of the closed curved area becomes equal to the command area; and displaying, on a monitor TV, a pattern representing the allowable range and a mark representing the position of the beam axis. When the marks falls within the allowable range, it is judged that the state of alignment of the beam axis is acceptable.
36 Citations
20 Claims
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1. A method of examining an alignment of headlamp beam of an automobile in which a first mark representing a position of a headlamp beam axis and a second mark representing an allowable range for the headlamp beam axis are displayed on a monitor TV and when said first mark falls within said allowable range, a judgement is made that the alignment of the beam axis is acceptable, comprising the steps of:
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taking up by a TV camera an image of a light distribution pattern of a headlamp beam on a screen; specifying a closed curved area surrounded by a line indicative of illumination intensity higher than a predetermined level in the taken-up image of the light distribution pattern; determining a position of a geometrical center of the specified closed curved area to display the position of the geometrical center on the monitor TV; measuring an area of the specified closed curved area; comparing the measured actual area of said specified closed curved area with a command area; and adjusting a quantity of light received by said TV camera in accordance with the result of the comparison until the measured actual area of said closed curved area becomes equal to said command area. - View Dependent Claims (2, 3)
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4. An apparatus for examining an alignment of headlamp beam of an automobile in which a first mark representing a position of a headlamp beam axis and a second mark representing an allowable range for the headlamp beam axis are displayed on a monitor TV and when said first mark falls within said allowable range, a judgement is made that the alignment of the beam axis is acceptable, comprising:
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means for taking up an image of a light distribution pattern of a headlamp beam on a screen to produce a video signal; means for specifying a closed curved area surrounded by a line indicative of illumination intensity higher than a predetermined level in the taken-up image of the light distribution pattern; means for determining a position of a geometrical center of the specified closed curved area to display the position of the geometrical center on the monitor TV; means for measuring an area of the specified closed curved area; means for comparing the measured actual area of said specified closed curved area with a command area; and means for adjusting a quantity of light received by said taking up means in accordance with the result of the comparison until the measured actual area of said closed curved area becomes equal to said command area. - View Dependent Claims (5, 6, 7, 8, 9, 10)
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11. A method of examining an alignment of headlamp beam of an automobile in which a first mark representing a position of a headlamp beam axis and a second mark representing an allowable range for the headlamp beam axis are displayed on a monitor TV and when said first mark falls within said allowable range, a judgement is made that the alignment of the beam axis is acceptable, comprising the steps of:
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taking up by a TV camera an image of a light distribution pattern of a headlamp beam on a screen; specifying a closed curved area surrounded by a line indicative of illumination intensity higher than a predetermined level in the taken-up image of the light distribution pattern; determining a position of a geometrical center of the specified closed curved area to display the position of the geometrical center on the monitor TV; measuring an area of the specified closed curved area; comparing the measured actual area of said specified closed curved area with a command area; and adjusting said predetermined level in accordance with the result of the comparison until the measured actual area of said closed curved area becomes equal to said command area. - View Dependent Claims (12, 13)
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14. An apparatus for examining an alignment of headlamp beam of an automobile in which a first mark representing a position of a headlamp beam axis and a second mark representing an allowable range for the headlamp beam axis are displayed on a monitor TV and when said first mark falls within said allowable range, a judgement is made that the alignment of the beam axis is acceptable, comprising:
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means for taking up an image of a light distribution pattern of a headlamp beam on a screen to produce a video signal; means for specifying a closed curved area surrounded by a line indicative of illumination intensity higher than a predetermined level in the taken-up image of the light distribution pattern; means for determining a position of a geometrical center of the specified closed curved area to display the position of the geometrical center on the monitor TV; means for measuring an area of the specified closed curved area; means for comparing the measured actual area of said specified closed curved area with a command area; and means for adjusting said predetermined level in accordance with the result of the comparison until the measured actual area of said closed curved area becomes equal to said command area. - View Dependent Claims (15, 16, 17, 18, 19, 20)
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Specification