| 摘要 |
PROBLEM TO BE SOLVED: To observe an optometric image invariably at the fixed brightness. SOLUTION: The eyeground Er of an eye E under optometry is illuminated by the light flux emitted from an observation light source 9, and an eyeground reflected image is formed on image pickup elements 8r, 8g, 8b via an apertured mirror 2, a photographing aperture 3, a focus lens 4, a photographing lens 5, and a color separating prism 7. This electric signal is amplified at the prescribed amplification factor through a signal amplifying means 16, is fed to an image control means 17, and is displayed on a television monitor 18. A photographer keeps the brightness of the eyeground image Er' displayed on the television monitor 18 constant while observing the television monitor 18 and adjusts the light quantity applied to the eye E and the picture quality of the television monitor 18. When the light quantity emitted from the observation light source 9 is increased as the applied voltage is increased, the amplification factor of the signal amplifying means 16 is reduced. When the light quantity of the observation light source 9 is decreased, the amplification factor is increased, thereby the brightness of the screen of the television monitor 18 is kept constant, thus noise is reduced, and the picture image is improved.
|
