| 摘要 |
PURPOSE: To realize a both side simultaneous access structure without impairing the compatibility of an information recording medium by keeping away either one of a first information reproducing means and a second information reproducing means from the position at a reproducing time. CONSTITUTION: A first convergent light irradiation means 5a and a second magnetic field generation means 6b are provided on the first surface 3a side of the information recording medium 3 and arranged on a fixed base 21. A second convergent light irradiation means 5b and a first magnetic field generation means 6a are provided on the second surface 3b side of the medium 3 and arranged on a movable base 22 movable in the vertical direction. A straight motion guide shaft 11 is provided upward vertically to the base 21, and the base 22 is movable along the shaft 11 in the vertical direction through a straight motion guide 10. A rack 12 is provided on one end of the base 22, and when a pinion gear 13 is engaged with the rack 12, driving force by a pinion gear drive means 9 is transmitted to the rack 12. Then, the gear 13 is rotated, and the base 22 is moved vertically, and thus, the means 5b and the means 6a are retreated from the medium 3. |
