PURPOSE: To make an objective lens driving device hard to oscillate in a high frequency range and obtain a stable servo system by fixing an objective lens and a coil for moving the objective lens on the same support member.
CONSTITUTION: The objective lens 11 is supported by an objective lens holder 12 as a single member, and the upper and lower ends of the objective lens holder 12 are supported with leaf springs 13 and 14 respectively. Coils 18, 19, and 20 are fixed to flanks of the objective lens holder 12. Consequently, a movable part is driven in one body, so a phase shift and high-frequency-range resonance become hard to occur even in a high frequency range (in general, ≥3kHz). The movable part is lightweight although the rigidity is increased, so the resonance point is raised to eliminate the need to increase a servo gain. Consequently, oscillations in lens drive become hard to occur. Further, the number of parts is decreased, so the constitution is simplified.
SONOBE HIROSHI
HARA YUTAKA
| JP57173131B |