Video camera having a function for correcting defective pixels of an image-recording device of semiconductor type, and a method for correcting defective pixels of an image-recording device of semiconductor type

摘要

When defective pixels of an image-recording device of semiconductor type in a video camera are corrected by signal processes, spot white noise is detected through closure of an iris (iris diaphragm, iris stop) and by comparing the signal level with the level of only a dark current. In addition, in this case a gain of an AGC circuit for controlling amplification of a video signal is increased, and a precise detection is carried out. By carrying out such a detection operation at the instant of the connection or disconnection of an energy source, the user is not inconvenienced. In the case of conventional photography, a reference level for which detection of spot white noise is fixed at an optimum value in agreement with a temperature of the image recording device of semiconductor type or with its ambient temperature or the gain of the AGC circuit, with the result that detection of the spot white noise is not influenced by the temperature of the image-recording device of semiconductor type or by the operating state of the AGC circuit.