EP0222238A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Pick-up device
Assignee: Sharp Corp
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Filing: 1986-10-25
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Granted: —
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Expires: 2006-10-25
Abstract
Abstract A pick-up device which includes a light source (7) and a condenser lens (2) for effecting recording and reproduction of information by projecting light beam as collected by the condenser lens onto a recording medium (1), and is characterized in that there is further provided a diffraction grating (3) between the light source (7) and the condenser lens (2) for dividing light returning from the recording medium (1) by the diffraction grating (3) so as to be led to a photo-detector (6), thereby to obtain an optical detection signal.
Inventors
- 👤 Hideaki Sato
- 👤 Yukio Kurata
- 👤 Yasuo Nakata
- 👤 Nobuo Ogata
- 👤 Teruaki Inoue
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-05 10:05
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/12; G11B7/135; G11B7/1353; G11B7/123
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
83 words
In a pick-up device which comprises a light source (7) and a condenser lens for effecting recording and reproduction of information by projecting light beam as collected by said condenser lens onto a recording medium 5(1), the improvement comprising a diffraction grating (3) provided between said light source (7) and said condenser lens for dividing light returning from the recording medium (1) by said diffraction grating (3) so as to be led to a photo-detector (6), thereby to obtain an optical detection signal.
Claim 2
Dependent Claim
83 words
In a pick-up device which comprises a light source (7) and a condenser lens for effecting recording and reproduction of information by projecting light beam as collected by said condenser lens onto a recording medium 5(1), the improvement comprising a diffraction grating (3) provided between said light source (7) and said condenser lens for dividing light returning from the recording medium (1) by said diffraction grating (3) so as to be led to a photo-detector (6), thereby to obtain an optical detection signal.
Claim 3
Dependent Claim
88 words
In a pick-up device which comprises a light source (7) and a condenser lens for effecting recording and reproduction of information by irradiating light beam as collected by said condenser lens onto a recording medium (1), the improvement comprising a diffraction grating (3′) having a blaze characteristic and provided between said light source (7) and said condenser lens for dividing light returning from the recording medium (1) by said diffraction grating (3′) so as to be led to a photo-detector (6), thereby to obtain an optical detection signal.
Claim 4
Dependent Claim
88 words
In a pick-up device which comprises a light source (7) and a condenser lens for effecting recording and reproduction of information by irradiating light beam as collected by said condenser lens onto a recording medium (1), the improvement comprising a diffraction grating (3′) having a blaze characteristic and provided between said light source (7) and said condenser lens for dividing light returning from the recording medium (1) by said diffraction grating (3′) so as to be led to a photo-detector (6), thereby to obtain an optical detection signal.
Claim 5
Dependent Claim
80 words
A pick-up device which comprises a light source (7) and a condenser lens for effecting recording and reproduction of information by irradiating light beam as collected by said condenser lens onto a recording medium (1), and a diffraction grating (3) provided between said light source (7) and said condenser lens for dividing light returning from the recording medium (1) by said diffraction grating (3) so as to be led to a photo-detector (6), thereby to obtain an optical detection signal.
Claim 6
Dependent Claim
80 words
A pick-up device which comprises a light source (7) and a condenser lens for effecting recording and reproduction of information by irradiating light beam as collected by said condenser lens onto a recording medium (1), and a diffraction grating (3) provided between said light source (7) and said condenser lens for dividing light returning from the recording medium (1) by said diffraction grating (3) so as to be led to a photo-detector (6), thereby to obtain an optical detection signal.
Claim 7
Dependent Claim
17 words
A pick-up device as claimed in Claim 3, wherein said diffraction grating (3) has a blaze characteristic.
References Cited (Backward Citations)
No citation records indexed.
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