Optical recording/reproducing by reducing laser power when there is a track jump

DETAILED DESCRIPTION OF THE INVENTION 1.
Industrial Field in Which the Invention is to be Utilized The present invention relates to an optical information recording and reproduction apparatus that performs discontinuous scanning of optical cards and the like, has an information recording medium as an object, and more particularly, has an optical output, of a laser source performing optical scanning, capable of being increased and decreased.
2.
Background Art The following is a description of the conventional technology, with reference to FIGS.
2 through 6.
Conventionally, when the recording and reproduction of information is performed using an optical information recording medium such as an optical card or the like, and it is necessary to have track jump or seek, tracking error signals are used as the basis for moving the optical head in the direction perpendicular to the tracks while the number of tracks crossed is counted, so that the light spot can be irradiated to a required track position.
One method of taking the tracking signals is, for example, the edge mirror method by the inventor of the invention of the present application and disclosed in Japanese Patent Laid Open Application No.
282167-1988.
This method is configured as shown in FIG.
2, and is used for focus error detection and tracking error detection.
In this configuration, the dispersed light from the laser is converted into parallel light beams by a collimator lens 2, passes through the diffraction grating 3, the beam splitter 4, the optical path change mirror 5 and the object lens 6 and a light spot is focussed to the surface of the optical information recording medium.
As shown in FIG.
3, this light spot passes from the surface of the optical information recording medium and backwards along the optical path to the beam splitter 4 and reaches the photodetectors 10, 11 after passing through the collimator lens 8 and the edge mirror 9.
Then, when the optical system is focussed, the light that is reflected from the optical information recording medium returns as parallel light in the same manner as the irradiated light