| 摘要 |
DISCLOSED ARE A LENS EFFICIENTLY MANUFACTURED INTO AN ACCURATE SHAPE AT A LOW COST, A MANUFACTURING METHOD THEREOF, AND AN OPTICAL PICKUP (10) USING THE LENS. THE LENS INCLUDES A GEOMETRICAL OPTICS PORTION (20) FOR CONVERGING LIGHT HAVING BEEN INCIDENT THEREON FROM ITS LIGHT INCOMING PLANE (20A), AND TWO DIFFRACTION OPTICS PORTIONS (21A,21B) PROVIDED ON THE LIGHT INCOMING PLANE (20A) AND A LIGHT OUTGOING PLANE (21B)OF THE GEOMETRICAL OPTICS PORTION (20), WHEREIN THE DIFFRACTION OPTICS PORTIONS (21A,21B) ARE MADE FROM A MATERIAL DIFFERENT FROM THAT OF THE GEOMETRICAL OPTICS PORTION (20).(FIG 4)
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