| 摘要 |
PURPOSE:To eliminate distortions, by giving compensation to the electric signal which is delivered from a picture input image pickup element in response to the distortion of an input picture due to an inclination produced between the optical axis of an image pickup system and a plane to be picked up so that the electric signal is suited to a picture which is automatically normalized. CONSTITUTION:The laser beams irradiated from laser light sources 5a-5d are reflected on a plane 1 to be picked up. The traveling direction of the reflected laser beams are changed through a lens system 2. Then these beams are reflected again by a dichroic mirror 6 and reaches a luminous point detecting image pickup element 7 to form a luminous point. The position of this luminous point varies by the inclination of the plane 1 to the optical axis of an image pickup system. A luminous point detecting circuit gives a raster scan to the element 7 and detects each center coordinates (Ui, Vi) of four luminous points from the electric signal output given from the element 7. A coordinate conversion coefficient arithmetic circuit 9 calculates and delivers the coefficient of a picture compensating function on the basis of the coordinates (Ui, Vi) of the detected luminous points and each center coordinate (Xi, Yi) of the luminous points which are previously registered, i.e., the value estimated in case the luminous points are set at the position of the plane 1. |
