Semiconductor laser device and optical pickup apparatus

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Reexamination Certificate

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C369S112070

Reexamination Certificate

active

06873581

ABSTRACT:
The semiconductor laser device includes a signal light diffraction grating, and a light receiving portion having a pair of photodiodes extending as two strips with a parting portion or a zonal gap interposed therebetween and receiving a focus error detecting beam from the signal light diffraction grating. The light receiving portion is arranged such that its longitudinal direction is orthogonal to the direction of diffraction grooves of the signal light diffraction grating. The pair of photodiodes is arranged such that a spot of the focus error detecting beam moves, due to temperature changes, in a range essentially limited to the parting portion therebetween. Thus, a semiconductor laser device and an optical pickup apparatus suppressing focus errors due to temperature changes and preventing reduction in signal strength can be obtained.

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International Office Action mailed Jun. 8, 2004, for Japanese Patent Application No. 2000-359446 filed Nov. 27, 2000, five pages.
Japanese Office Action mailed Aug. 24, 2004, for Japanese Patent Application Number 2000-359446 filed Nov. 27, 2000, four pages.

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