Optical pickup apparatus and photodetector

Abstract

The invention discloses an optical pickup device and a light detector. The first photodiode (25) for BD receives the laser light (L2) separated from the laser light (L1) emitted from the first semiconductor laser (11), detects the laser power of the first semiconductor laser (11), and conducts the output current i2 output. The 2nd photodiode (26) that DVD / CD is used receives the laser light (L4) separated from the laser light (L3) that emits from the 2nd semiconductor laser (12), detects the laser power of the 1st semiconductor laser (12), and outputs current i5 for output. The output terminal of the first photodiode (25) is connected to the output terminal of the second photodiode (26), and the output current i2 and the output electrode i5 are input to the input terminal of the same first current-voltage conversion circuit (30).

Description

technical field [0001] The present invention relates to an optical pick-up device and a photodetector capable of recording and reproducing information on an information recording medium. The optical pickup device for reproducing particularly relates to an optical pickup device capable of controlling the output power of a plurality of semiconductor laser elements by a single circuit, and a photodetector used in the optical pickup device. Background technique [0002] As a device capable of recording and reproducing large-capacity information, an optical disc device has been known in the past. In an optical disc device, an optical pickup device (hereinafter, sometimes simply referred to as "optical pickup") for recording and reproducing information has a semiconductor laser element (hereinafter, sometimes simply referred to as "semiconductor laser") as a light source. [0003] An optical disc device records and reproduces information by irradiating an optical disc with laser ...

AI Technical Summary

Problems solved by technology

Installing the attached current-voltage conversion circuit corresponding to the number will hinder the miniaturization of the optical pickup head

Furthermore, the installation of multiple circuit components in the optical pickup head will lead to complicated circuit wiring, and the high-speed performance of laser power detection will be affected due to the parasitic capacitance of the wiring.

[0015] The problem with the conventional technology described in JP-A-2002-109771 is that it is necessary to provide a current-voltage conversion circuit for each photodetection element

Although the conventional technologies described in JP-A-2002-319175, JP-A-2003-217160, and JP-A-2004-133987 all set one light detection element, the problem is that due to multiple The emitted light of the semiconductor laser is directed to a photodetection element, thereby restricting the optical system and affecting the freedom of optical design

Images