| 摘要 |
PURPOSE:To obtain a picture consisting of clear bright and dark parts by supplying incident light from a subject to image pickup tubes at an adequate ratio of the quantity of incident light and by mixing their outputs. CONSTITUTION:When a beam from subject 1 enters by way of objective lens 2 and half-mirror 3, image pickup tube 4 outputs only a signal of a dark part region and image pickup tube 7 outputs a signal nearly proportional to the quantity of the incident light. Outputs of both image pickup tubes 4 and 7 are amplified 10 and 13 respectively and the dark-part signal amplified 10 has white information of a certain level or higher clipped by clipper 11 to mix 12 the information and the signal amplified 13, thereby obtaining a signal of the best amplitude level. This signal has the bright part area and dark-part area section clearly and a synchronizing signal is added 15 to the signal, thereby sending a composite video signal. |
