| 摘要 |
In movie house (10) or similar installation for projecting (16) still or moving normal visible images on a screen (12), a laser device (18) is used to project an infrared spoiling image simultaneously with the normal visible image. When a camcorder (22) is used to record the screen (12) to make illegal copies of the normal visible images, the light sensitive elements of the camcorder (22) convert the invisible spoiling image into a corresponding normal visible image thereby spoiling it. |
