OPTICAL INFORMATION RECORDING AND REPRODUCING DEVICE

PURPOSE:To warn the reduction of an emitting light quantity to an operator and to improve the reliability of a recording and reproducing device by detecting the light quantity of the emitting light from an optical head, comparing the output of a light quantity detector with a prescribed reference level and discriminating the light output abnormality of an optical head based on the compared result. CONSTITUTION:The emitting light from an objective lens 26 of an optical head 21 of an optical information recording and reproducing device is detected by an emitting light quantity detector 1 arranged at the position to light-receive all and the output of the detector 1 and is compared with a criterion voltage 11 by a comparator 2. The AND of an abnormality detecting signal 51 of the output of the comparator 2 and an emitting light quantity measuring permitting signal 41 of the head 21 is obtained, and a warning signal 52 is outputted. Based on the compared result of the output of the emitted objective lens 26 and the prescribed reference level, the abnormality of the optical head 21 is decided, the reduction of the emitting light quantity is warned to the operator and the reliability of the recording and reproducing device is improved.