Title:
OPTICAL HEAD DEVICE, OPTICAL INFORMATION DEVICE AND INFORMATION PROCESSING DEVICE
Document Type and Number:
WIPO Patent Application WO/2011/161914
Kind Code:
A1
Abstract:
An optical head device is provided with a light shielding area (7y) which is disposed in the path of a beam of reflection light that was reflected by the recording layer at which a blue light beam is collimated, and which shields reflection light that is reflected by at least two recoding layers and is incident in an area of an optical detector (9) where the reflection light reflected by at least two recoding layers mutually interferes if at least the two recording layers exist on the incident side or the side opposite the incident side of the blue light beam with respect to the recording layer on which the blue light beam is collimated. The light shielding area (7y) is not formed on the optical axis of the reflection light reflected by the recording layer at which blue light is collimated. The signal to noise ration of the signal output by the optical detector is thereby improved by this structure.
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Inventors:
KOMMA, Yoshiaki (())
金馬 慶明 (())
金馬 慶明 (())
Application Number:
JP2011/003452
Publication Date:
December 29, 2011
Filing Date:
June 16, 2011
Export Citation:
Assignee:
PANASONIC CORPORATION (1006, Oaza Kadoma Kadoma-sh, Osaka 01, 〒5718501, JP)
パナソニック株式会社 (〒01 大阪府門真市大字門真１００６番地 Osaka, 〒5718501, JP)
KOMMA, Yoshiaki (())
パナソニック株式会社 (〒01 大阪府門真市大字門真１００６番地 Osaka, 〒5718501, JP)
KOMMA, Yoshiaki (())
International Classes:
G11B7/135
Attorney, Agent or Firm:
KOTANI, Etsuji et al. (Osaka Nakanoshima Building 2nd Floor, 2-2 Nakanoshima 2-chome, Kita-ku, Osaka-sh, Osaka 05, 〒5300005, JP)
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