EP0168699A2
Expired / Lapsed
EP
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Electro-optical servo transducer head
Assignee: International Business Machines Corp
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Filing: 1985-07-01
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Granted: —
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Expires: 2005-07-01
Abstract
Abstract A read/write electromagnetic transducer slider head (70) includes a monolithic semiconductor chip (68) provided with an LED and a light detector. A spherical lens (66) is located in a tapered hole (72) in the head, for focussing light from the LED onto the surface of a magnetic data storage disk (74), and for collecting reflected light and for directing it to the light detector. The LED light detector and lens are centrosymmetric about their axis. Servo positioning marks on the disk surface are sensed, and the resulting servo signal is used to correct the position of the head relative to the disk.
Inventors
- 👤 Thomas Herman Distefano
- 👤 Halil Burhan Bakoglu
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-23 09:18
CPC Classifications
H; H10; H10F; H10F55/00; H10F55/20; H10F55/25; H10F55/255; B; B01; B01J; B01J23/00; B01J23/16; B01J23/24; B01J23/28; B01J23/30; G; G11; G11B; G11B21/00; G11B21/02; G11B21/10; G11B21/106; G11B5/00; G11B5/48; G11B5/58; G11B5/596; G11B5/59677; H10F77/00; H10F77/40; H10F77/407; B01J21/00; B01J21/06; B01J21/08
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
88 words
Electro-optical servo transducer head (20) suitable for sensing the position of the head relative to servo information (22) on a data storage disk (26), including a light source (34) and a light detector (36) respectively for illuminating the servo information and for sensing the servo information by the reflected light, characterised in that light source and light detector are coaxial with a lens (30) included in the head through which the illuminating and reflected light pass, the light source, light detector and lens being centrosymmetric about their axis.
Claim 2
Dependent Claim
88 words
Electro-optical servo transducer head (20) suitable for sensing the position of the head relative to servo information (22) on a data storage disk (26), including a light source (34) and a light detector (36) respectively for illuminating the servo information and for sensing the servo information by the reflected light, characterised in that light source and light detector are coaxial with a lens (30) included in the head through which the illuminating and reflected light pass, the light source, light detector and lens being centrosymmetric about their axis.
Claim 3
Dependent Claim
25 words
The transducer head of claim 1 in which the light source and light detector are both formed in a monolithic semiconductor chip (38, 40, 42).
Claim 4
Dependent Claim
68 words
The transducer head of claim 2, where said light detector is an area detector comprising an annulus around said light source, and wherein said lens is a composite lens with at least two portions having different focal lengths, the focal length for imaging light from said source onto said storage medium being less than the focal length for imaging light from said storage medium to said light detector.
Claim 5
Dependent Claim
50 words
The transducer head of claim 2, where said light detector is located below said light source in said semiconductor chip, wherein light reflected from said data storage medium passes through said light source to said detector, the semiconductor material comprising said light source being substantially transparent to said reflected light.
Claim 6
Dependent Claim
40 words
The transducer head of claim 4, wherein said light source and said light detector are p-n junctions in said semiconductor chip, and where the bandgap of the light source junction is greater than the bandgap of said light detector junction.
Claim 7
Dependent Claim
22 words
The transducer head of claim 5, wherein said light source junction is forward biased and said light detector junction is reversed biased.
Claim 8
Dependent Claim
15 words
The transducer head of claim 1 or 2, wherein said lens is a spherical lens.
Claim 9
Dependent Claim
26 words
The transducer head of claim 7 dependent from claim 2 wherein said lens is located substantially midway between said semiconductor chip and said data storage disk.
Claim 10
Dependent Claim
15 words
The transducer head of claim 1 or 2, where said lens is a plano-convex lens.
Claim 11
Dependent Claim
21 words
The transducer head of any preceding claim, including means for writing and reading data record tracks on said data storage disk.
References Cited (Backward Citations)
No citation records indexed.
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