Abstract: An optical disc apparatus comprises an overcurrent detector and when the overcurrent detector detects an overcurrent during a recording operation or a reproduction operation and during an operation for controlling a focus of an objective lens, a rotation speed of an optical disc is reduced and an actuator is controlled to cause the objective lens to be in a retracted state under the condition that a disc motor exerts brake force. The objective lens is in the retracted state until the rotation speed of the optical disc becomes equal to or smaller than a predetermined value and when the rotation speed of the optical disc is equal to or smaller than the predetermined value, the objective lens is released from the retracted state.

Abstract: An optical disc apparatus comprises an overcurrent detector and when the overcurrent detector detects an overcurrent during a recording operation or a reproduction operation and during an operation for controlling a focus of an objective lens, a rotation speed of an optical disc is reduced and an actuator is controlled to cause the objective lens to be in a retracted state under the condition that a disc motor exerts brake force. The objective lens is in the retracted state until the rotation speed of the optical disc becomes equal to or smaller than a predetermined value and when the rotation speed of the optical disc is equal to or smaller than the predetermined value, the objective lens is released from the retracted state.

Abstract: To eliminate scratches on a disc surface of an optical disc in an emergency eject operation, there is provided an optical disc apparatus including: an emergency eject detector for detecting an emergency eject instruction; a rotation speed detector for producing a signal corresponding to the rotation speed of the optical disc; and a logical circuit unit which is operated by a first signal from the emergency eject detector and a second signal from the rotation speed detector, and when the second output signal is not more than a reference level, produces a third signal so as to input a control signal for instructing stop of the actuator control into an actuator controller. After detection of the emergency eject instruction, the apparatus performs the actuator control without producing the third signal until the rotation speed is not more than a predetermined value. Thus the objective lens is made in a focus control state or in a saving state in which the objective lens is separated from the disc surface.

Abstract: An apparatus for adding isopleths to image data includes an input device for sequentially inputting image data to be displayed on an image screen of a display device, a horizontal delay circuit for delaying the inputted data by one horizontal scanning period, a column comparator for comparing the inputted data, that is, a sample, with a delayed sample from the horizontal delay circuit to thereby generate a signal indicating a sample to be converted into isopleth data, a sample delay circuit for delaying the sample outputted from the horizontal delay circuit by one sampling period, a row comparator for comparing the sample outputted from the horizontal delay circuit with the sample outputted from the sample delay circuit to thereby generate a signal indicating a sample to be converted into isopleth data, and an isoplete data generator responsive to the output of the column and row comparators for replacing the indicated input sample by predetermined distinguishable data and for outputting the predetermined dis