OPTICAL PICKUP DEVICE, AN OPTICAL INFORMATION RECORDING/REPRODUCING DEVICE, AN EXPANDER LENS, A COUPLING LENS AND AN OPTICAL ELEMENT FOR COMPENSATING FOR A CHROMATIC ABERRATION, CONSEQUENTLY PROPERLY RECORDING/REPRODUCING INFORMATION WHILE MAINTAINING COMPATIBILITY WITH VARIOUS KINDS OF OPTICAL DISKS

摘要

PURPOSE: An optical pickup device, an optical information recording/reproducing device, an expander lens, a coupling lens and an optical element for compensating for a chromatic aberration are provided to record/reproduce information while maintaining compatibility with various kinds of optical disks, thereby realizing miniaturization, lightness, and a low cost. CONSTITUTION: An optical pickup device(PU1) comprises as follows. A high-density optical disk(HD) module(MD1) integratedly comprises a semiconductor laser(LD1) and an optical detector(PD1). The first emitting point(EP1) emits a light to inject a 655nm laser light flux. The second emitting point(EP2) injects a 785nm laser light flux. The first light receiving portion(DS1) receives a reflected light flux from an information recording surface(RL2) of a DVD. The second light receiving portion(DS2) receives a reflected light flux from an information recording surface(RL3) of a CD. A laser module(LM) consists of a prism(PS). An objective lens unit(OU) consists of an objective lens(OBJ), a biaxial actuator(AC2), and an iris(STO). An expander lens(EXP) is composed of a polarized beam splitter(BS), a collimator lens(COL), and negative/positive lenses(NL,PL). An expander lens unit(EU) is composed of a 1-axis actuator(AC1).