Method of calibrating a CCD camera

• US 5,444,481 A
• Filed: 12/06/1994
• Issued: 08/22/1995
• Est. Priority Date: 01/15/1993
• Status: Expired due to Term

• Current Assignee: Sanyo Machine Works Ltd. (Panasonic Holdings Corporation)
• Original Assignee: Sanyo Machine Works Ltd. (Panasonic Holdings Corporation)
• Inventors: Aoki, Yoshihide, Ohshima, Masatoshi
• Primary Examiner(s): Razavi, Michael T.
• Assistant Examiner(s): CHRISTENSEN, ANDREW BRUCE
• Application Number:
  US08/354,054
• Time in Patent Office: 259 Days
• Field of Search: 356/141.4, 356/400, 348/180, 348/187, 348/134, 348/94, 348/95
• US Class Current: 348/187
• CPC Class Codes: H04N 17/002 for television cameras
• CPC Class Codes: H04N 25/61 the noise originating only from the lens unit, e.g. flare, shading, vignetting or "cos4"

Abstract

A method of calibrating a CCD camera comprising those sequential processes comprises steps of shifting a spot light source held by a positioning device, in front of a fixed CCD camera between two remote points on a visual line in order that light beam in the center of the light source can be incident upon predetermined picture element of a solid sensor built in the CCD camera, computing angles between a plurality of visual lines generated by shifting the light source and the optical axis of the CCD camera based on position data related to the positioning device, and calibrating the corresponding relationship between the angle of light beam incident upon the CCD camera and the predetermined picture elements built in the solid sensor.

Claims

1. A method of calibrating a CCD camera comprising the steps of:

placing a spot light source, held by a positioning device, in front of a fixed CCD camera, at a first point on an optical axis of the CCD camera so that a light beam from said light source is incident upon one of a plurality of picture elements in a center of a solid sensor built in said CCD camera;

shifting said spot light source a predetermined distance along said optical axis to a second point remote from said first point while insuring that the light beam from said spot light source is incident upon said one of said plurality of picture elements;

shifting said spot light source in front of said fixed CCD camera by first, shifting to a third point which is apart from said optical axis so that the light beam from said light source is incident upon another one of said plurality of picture elements of said solid sensor, and second, shifting said spot light source to a fourth point while insuring that the light beam from said spot light source is incident upon said another one of said plurality of picture elements;

computing angles between a plurality of light beam lines, generated by shifting said spot light source in a plurality of directions from said optical axis of said CCD camera based on position data related to said positioning device; and

calibrating a corresponding relationship between each angle of the light beams incident upon said CCD camera and said plurality of picture elements built in said solid sensor.