EP0107461A1
Expired / Lapsed
EP
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Optical signal reading device
Assignee: Mitsubishi Electric Corp
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Filing: 1983-10-14
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Granted: —
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Expires: 2003-10-14
Abstract
Abstract An optical signal reading device comprising a laser light source (101), an objective (107) slidable in the direction of the optical axis which is at right angles to the disc surface of a disc-like record carrier, a light detector (110) for receiving the reflected light coming from the disc surface via the objective, and a beam splitter (104) comprised of a single optical part disposed between the light source (101), light detector (1 10), and objective (107), said splitter having a pair of reflecting surfaces (114) and (115) which are disposed approximately parallel to each other to ensure that the incident light from the light source (101) and the reflected light guided to the light detector (110) are parallel and opposite to each other.
Inventors
- 👤 Kenjiro C/O Mitsubishi Denki K.K. Kime
- 👤 Kazuo C/O Mitsubishi Denki K.K. Okada
- 👤 Mitsushige C/O Mitsubishi Denki K.K. Kondou
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-27 05:30
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/12; G11B7/135; G11B7/1356; G11B7/08
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
111 words
An optical device comprising: a light source (101), an objective (107) for focusing light from the light source on a storage surface of a recording medium, a light detector (110) for receiving light reflected from the storage surface of the recording medium by way of the objective (107), and a beam splitter (104) arranged between the light source (101), the light detector (110), and the objective (107), characterised in that the parts are arranged such that the path of the light from the light source (101) incident on the beam splitter (104) is parallel to the path of the light directed from the beam splitter (104) to the light detector (110).
Claim 2
Dependent Claim
111 words
An optical device comprising: a light source (101), an objective (107) for focusing light from the light source on a storage surface of a recording medium, a light detector (110) for receiving light reflected from the storage surface of the recording medium by way of the objective (107), and a beam splitter (104) arranged between the light source (101), the light detector (110), and the objective (107), characterised in that the parts are arranged such that the path of the light from the light source (101) incident on the beam splitter (104) is parallel to the path of the light directed from the beam splitter (104) to the light detector (110).
Claim 3
Dependent Claim
150 words
An optical signal reading device comprising: a light source (101), an objective (107) slidable in the direction of the optical axis which is at right angles to the disc surface of a disc-like record carrier, said objective serving to focus the light emitted from said light source on the disc surface as a spot of light, the reflected light from the disc surface falling on said objective, a light detector (110) which receives the reflected light coming from said disc surface via said objective, and a beam splitter (-104) composed of a single optical part disposed between said light source, light detector, and objective, characterised by said splitter having a pair of reflecting surfaces (114, 115) which are disposed approximately parallel to each other to ensure that the incident light from said light source and the reflected light guided to said light detector are parallel and opposite to each other.
Claim 4
Dependent Claim
150 words
An optical signal reading device comprising: a light source (101), an objective (107) slidable in the direction of the optical axis which is at right angles to the disc surface of a disc-like record carrier, said objective serving to focus the light emitted from said light source on the disc surface as a spot of light, the reflected light from the disc surface falling on said objective, a light detector (110) which receives the reflected light coming from said disc surface via said objective, and a beam splitter (-104) composed of a single optical part disposed between said light source, light detector, and objective, characterised by said splitter having a pair of reflecting surfaces (114, 115) which are disposed approximately parallel to each other to ensure that the incident light from said light source and the reflected light guided to said light detector are parallel and opposite to each other.
Claim 5
Dependent Claim
86 words
An optical device as set forth in,Claim 1 or 2, characterised in that said beam splitter (104) is a single optical part of the type having a first prism having a first reflecting surface (114) which reflects the light from the light source (101) and transmits the reflected light from the objective (107), and a second prism having a second reflecting surface (115) which reflects the reflected light from the disc surface transmitted through said first reflecting surface, said first and second prisms being joined together.
Claim 6
Dependent Claim
25 words
An optical device as set forth in Claim 3, characterised in that said first and second prisms are joined together through a light-transmitting member (46).
Claim 7
Dependent Claim
58 words
An optical device as set forth in Claim 3, characterised in that said first and second prisms are joined together through a non-light-transmitting member (57) having a hollow portion (56) serving as a path of light, so that the reflected light transmitted through the first reflecting surface is guided to the second reflecting surface through said hollow portion.
Claim 8
Dependent Claim
77 words
An optical device as set forth in Claim 1 or 2, characterised in that said beam splitter (21) is a single optical part in which a first prism having a first reflecting surface (24) which transmits the light from the light source and reflects the reflected light from the disc surface via the objective, and a second prism having a second reflecting surface (25) which reflects the light reflected by said first reflecting surface, are joined together.
Claim 9
Dependent Claim
24 words
An optical device as set forth in Claim 6, characterised in that said first and second prisms are joined together through a light-transmitting member.
Claim 10
Dependent Claim
60 words
An optical device as set forth in Claim 6, characterised in that said first and second prisms are joined together through a non-light-transmitting member having a hollow portion serving as a path of light, so that the reflected light from the disc surface reflected by the first reflecting surface is guided to the second reflecting surface through said hollow portion.
Claim 11
Dependent Claim
178 words
An optical device as set forth in Claim 1 or 2, characterised in that between said light source (101) and said beam splitter (104), there are installed a lens (102) for correcting the diversion angle of the light emitted from said light source and a diffraction grating (103) for diffractively separating the light from said lens into a plurality of light beams, between said beam splitter and said objective, there are installed a phase plate for separating the light falling on said disc surface and the light reflected from the disc surface from each other, and a mirror for reflecting the incident light and reflected light so that the incident light guided through said beam splitter can be guided to said objective and so that reflected light from the disc surface guided through the objective can be guided to said beam splitter, and between said beam splitter and said light detector, there is installed a cylindrical lens (109) for producing astigmatism in the reflected light from the disc surface, said light detector (110) being a photoelectric conversion element.
References Cited (Backward Citations)
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