| 摘要 |
PURPOSE:To widen a dynamic range without generation of the blooming occuring in the saturation of an image pickup element by disposing a light transmittable medium of which the light transmittance changes reversibly according to the quantity of input light on the photodetecting surface side of an image pickup means which can detect light and convert the same to an electrical signal. CONSTITUTION:A light transmittable medium of which the light transmittance changes reversibly according to the quantity of input light is disposed on the photodetecting surface side of an image pickup means which detects light and converts the same to an electrical signal. Such image pickup element couples photochromic glass (PCG) 2 to the photodetecting surface of, for example, a change coupled device (CCD) 1. Incident light L passes through a lens 3 and enters the PCG 2 from which the light is detected by the CCD1 and is outputted to a signal processing circuit. The trasmittance of the PCG2 increases or decreases according to the quantity of the light L by which dimming is accomplished automatically. The electrical signal converted by the CCD1 is thus compressed within a saturation level range and is taken out so that the dynamic range of the incident light signal can be expanded. The blooming occuring in the saturation of the CCD1 is thus prevented and the increase in the size of the CCD chip is obviated. The device is suitable for the top end of an endoscope. |
