EP0294902A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Optical scanning device, mirror objective suitable for use therein and an optical recording and/or reproducing apparatus provided therewith
Assignee: Koninklijke Philips NV
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Filing: 1988-06-07
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Granted: —
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Expires: 2008-06-07
Abstract
Abstract A scanning device for an optical recording and/or reproducing apparatus comprises an objective system which is composed of reflectors (33, 35) arranged on the surface of a transparent body (30). Since the reflectors both focus the radiation beam (20) and fold it within the body (30), a very compact write and/or read unit is obtained. The scanning device may also be given a very robust and stable form by fixing the radiation source (40) and the detection system (60) to the surface of the transparent body (30).
Inventors
- 👤 Willem Gerard Opheij
- 👤 Josephus Johannes Maria Braat
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-27 20:20
CPC Classifications
G; G02; G02B; G02B17/00; G02B17/08; G02B17/0856; G02B17/086; G02B17/0804; G02B17/0808; G02B27/00; G02B27/10; G02B27/108; G02B27/1086; G02B27/1093; G02B27/14; G02B27/144; G02B27/16; G11; G11B; G11B7/00; G11B7/12; G11B7/135; G11B7/1353; G11B7/1372; G11B7/1374; G11B7/1381; G11B2007/13725; G11B7/08; G11B7/09; G11B7/0908; G11B7/0909; G11B7/0916
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
203 words
A scanning device for scanning an information plane in an optical record carrier by means of optical radiation, which scanning device comprises a radiation source for supplying a scanning beam and a mirror objective for focussing the scanning beam to a scanning spot in the information plane, characterized in that the mirror objective comprises a transparent body which is bounded by a first surface on a side facing the radiation source and by a second surface on a side remote from the radiation source, said first surface having a first radiation window which is centrally located around the optical axis of the mirror objective and having a first reflector reflecting on the inside and being arranged around the first radiation window, said second surface having a second reflector reflecting on the inside and being centrally located around the optical axis of the mirror objective, and having a second radiation window located around the second reflector, the radiation path of the scanning beam from the radiation source to the record carrier entering the mirror objective via the first radiation window, reversing its direction successively on the second reflector and on the first reflector and finally leaving the mirror objective through the second radiation window.
Claim 2
Dependent Claim
203 words
A scanning device for scanning an information plane in an optical record carrier by means of optical radiation, which scanning device comprises a radiation source for supplying a scanning beam and a mirror objective for focussing the scanning beam to a scanning spot in the information plane, characterized in that the mirror objective comprises a transparent body which is bounded by a first surface on a side facing the radiation source and by a second surface on a side remote from the radiation source, said first surface having a first radiation window which is centrally located around the optical axis of the mirror objective and having a first reflector reflecting on the inside and being arranged around the first radiation window, said second surface having a second reflector reflecting on the inside and being centrally located around the optical axis of the mirror objective, and having a second radiation window located around the second reflector, the radiation path of the scanning beam from the radiation source to the record carrier entering the mirror objective via the first radiation window, reversing its direction successively on the second reflector and on the first reflector and finally leaving the mirror objective through the second radiation window.
Claim 3
Dependent Claim
17 words
A scanning device as claimed in Claim 1, characterized in that the first reflector is curved aspherically.
Claim 4
Dependent Claim
19 words
A scanning device as claimed in Claim 1, characterized in that the first and second reflectors are curved spherically.
Claim 5
Dependent Claim
19 words
A scanning device as claimed in Claim 3, characterized in that the second radiation window is also curved spherically.
Claim 6
Dependent Claim
32 words
A scanning device as claimed in Claim 1, 2, 3 or 4, characterized in that the transparent body comprises at least two portions which are manufactured from materials having different refractive indices.
Claim 7
Dependent Claim
57 words
A scanning device as claimed in Claim 1, 2, 3, 4 or 5 for scanning a reflective information plane in which the scanning device includes a radiation-sensitive detection system, characterized in that the mirror objective comprises a beam-splitting element for spatially separating the beam emitted by the radiation source and the beam reflected from the information plane.
Claim 8
Dependent Claim
20 words
A scanning device as claimed in Claim 6, characterized in that the beam-splitting element comprises a grating or a hologram.
Claim 9
Dependent Claim
28 words
A scanning device as claimed in Claim 7, characterized in that the grating or hologram is a reflection grating or a reflection hologram provided on the second reflector.
Claim 10
Dependent Claim
29 words
A scanning device as claimed in Claim 7, characterized in that the grating or hologram is a transmission grating or a transmission hologram provided on the first radiation window.
Claim 11
Dependent Claim
51 words
A scanning device as claimed in Claim 7, characterized in that the transparent body of the mirror objective comprises two interconnected portions and in that the grating or hologram is a transmission grating or a transmission hologram provided on one of the two portions on a side facing the other portion.
Claim 12
Dependent Claim
28 words
A scanning device as claimed in Claim 7, 8, 9 or 10, characterized in that the grating or hologram comprises at least two sub-gratings having different grating parameters.
Claim 13
Dependent Claim
27 words
A scanning device as claimed in Claim 7, 8, 9 or 10, characterized in that the grating or hologram has a constant or linearly varying grating period.
Claim 14
Dependent Claim
26 words
A scanning device as claimed in any one of the preceding Claims, characterized in that the radiation source is optically connected to the first radiation window.
Claim 15
Dependent Claim
56 words
A scanning device as claimed in any one of the preceding Claims, which is provided with a radiation sensitive detection system, characterized in that the radiation-sensitive detection system is arranged on the first radiation window in the radiation path of radiation which has been reflected from the information plane and which has traversed the mirror objective.
Claim 16
Dependent Claim
23 words
A transparent body comprising inwardly reflecting reflectors suitable for use in a scanning device as claimed in any one of the preceding Claims.
Claim 17
Dependent Claim
21 words
An optical record and/or reproducing apparatus provided with a scanning device as claimed in any one of Claims 1 to 14.
References Cited (Backward Citations)
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