| 摘要 |
PURPOSE:To detect the line of sight of an observer with high accuracy and to eliminate necessity for the observer itself to correct the line of sight by calculating a distance from the prescribed surface of a lighting means or a photo-detecting means to a prescribed position in the eyeball of the observer by a distance detecting means and calculating the glance of the observer by using output signals from the photo-detecting means and distance detecting means. CONSTITUTION:In addition to a normal light source 4 for lighting, a light source 5 for distance detection is provided and infrared ray emitted from the light sources 4 and 5 goes to be parallel light by a projection lens 6 and lights up the cornea 1 of the eyeball. At such a time, in a position distant from a curvature center O of the cornea 1 by a distance l4 in the cornea 1 side, first Purkinje pictures (d) and (e) are generated by the light flux reflected on the surface of the cornea 1. The first Purkinje pictures (d) and (e) are projected in the positions of coordinates Zd' and Ze' on an image sensor 9 by a photo-detection lens 7. The arithmetic is executed by an arithmetic means 11 and a rotational angle theta of an optical axis B of the eyeball is detected. Then, the view axis of the eyeball is calculated and the line of sight of the patient is detected. |
