Light receiving amplification element
AssigneeSharp Kabushiki Kaisha
InventorsTakanori Okuda, Masaya Ohnishi
Life of this patent
Estimating the term…
Abstract
The object of the invention is to provide a light receiving amplification element applicable to an optical pickup apparatus comprising a semiconductor two-wavelength laser element and one condensing lens. The light receiving amplification element is provided with a plurality of light receiving portions corresponding to different wavelengths, a plurality of trans-impedance type amplifiers connected to the light receiving portions according to the different wavelengths and adaptable to the different wavelengths and switching portion for switching output from the trans-impedance type amplifier according to each of the wavelengths.
Claims15
A light receiving amplification element which is used for an optical pickup apparatus including a semiconductor laser having a plurality of light emitting points from which different wavelength light is emitted each other, and an optical element for irradiating an optical disk with emitting light from the semiconductor laser and guiding reflecting light on the optical disk to the light receiving amplification element, the light receiving amplification element comprising:
- a plurality of light receiving portions corresponding to the different wavelengths;
- a plurality of trans-impedance type amplifiers connected to the light receiving portions according to the different wavelengths and corresponding to the different wavelengths;
- and
- switching means for switching outputs from the trans-impedance type amplifiers according to each of the wavelengths.
A light receiving amplification element which is used for an optical pickup apparatus including a semiconductor laser having a plurality of light emitting points from which different wavelength light is emitted each other and an optical element for irradiating an optical disk with emitting light from the semiconductor laser and guiding reflecting light on the optical disk to the light receiving amplification element, the light receiving amplification element comprising:
- a plurality of light receiving portions corresponding to the different wavelengths;
- a plurality of trans-impedance type amplifiers connected to the plurality of light receiving portions and corresponding to a plurality of optical disks with different reflectance;
- and
- switching means for switching outputs from the trans-impedance type amplifiers according to the optical disk,
- the light receiving amplification element being commonly connected between outputs from the plurality of light receiving portions and inputs to the plurality of trans-impedance type amplifier.
An optical pickup apparatus comprising:
- a semiconductor laser having a plurality of light emitting points from which different wavelength light is emitted each other;
- a light receiving amplification element including:
- a plurality of light receiving portions corresponding to the different wavelengths;
- a plurality of trans-impedance type amplifiers connected to the light receiving portions according to the different wavelengths and corresponding to the different wavelengths;
- and
- switching means for switching an output from the trans-impedance type amplifier according to each of the wavelengths;
- and
- an optical element for irradiating an optical disk with emitting light from the semiconductor laser and guiding reflecting light on the optical disk to the light receiving amplification element.
An optical pickup apparatus comprising:
- a semiconductor laser having a plurality of light emitting points from which different wavelength light is emitted each other;
- a light receiving amplification element including:
- a plurality of light receiving portions corresponding to the different wavelengths;
- a plurality of trans-impedance type amplifiers connected to the plurality of light receiving portions and corresponding to a plurality of optical disks with different reflectance;
- and
- switching means for switching an output from the trans-impedance type amplifier according to the optical disk,
- the light receiving amplification element being commonly connected between outputs from the plurality of light receiving portions and inputs to the plurality of trans-impedance type amplifier;
- and
- an optical element for irradiating an optical disk with emitting light from the semiconductor laser and guiding reflecting light on the optical disk to the light receiving amplification element.
Dependencies are inferred from the claim text.