Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
207 words
A magneto-optical head device comprising: a semiconductor laser (1); an objective lens system (3,4) which converges light emitted from said semiconductor laser on a magneto-optical recording medium; a diffractive element (2) which is provided between said semiconductor laser and said objective lens system and has diffraction efficiency dependent on a polarization direction of incident light; a photodetecting means (6,7) receiving light which is reflected from said magneto-optical recording medium and then diffracted at said diffractive element; and an analyzing means (8,9) which is provided between said diffractive element and said photodetecting means and which splits at least a part of the diffracted light from said diffractive element into two polarized components orthogonal to each other, characterized in that said diffractive element has characteristics with which the polarized component in a predetermined direction in the incident light is partially diffracted and the polarized component orthogonal thereto is substantially totally diffracted, and said diffractive element being disposed such that the polarization direction of the light emitted from said semiconductor laser coincides with said predetermined direction, and said analyzing means is disposed such that said two polarized components split thereby make an angle of about 45° with respect to the polarization direction of the light emitted from said semiconductor laser.
Claim 2
Dependent Claim
67 words
The magneto-optical head device according to claim 1, in which said analyzing means includes a half-wave plate (8) and a polarizing beam splitter (9), whereby -1st order diffracted light from said diffractive element is transmitted through said half-wave plate (8) and divided by said polarizing beam splitter (9) into two polarized light components which are orthogonal to each other and which are detected by said photodetecting means.
Claim 3
Dependent Claim
57 words
The magneto-optical head device according to claim 1, in which said analyzing means includes polarizing beam splitters (52,53) whereby -1st order diffracted beams of light from said diffractive element (49) are divided by said polarizing beam splitters into two polarized light components which are orthogonal to each other and which are detected by said photodetecting means (50,51).
Claim 4
Dependent Claim
39 words
The magneto-optical head device according to claim 1, in which said semiconductor laser (1), said analyzing means (8,9) and said photodetecting means (50,51) are contained in a package (82) and said diffractive element (2) is cemented on said package.
Claim 5
Dependent Claim
266 words
A magneto-optical head device comprising: a semiconductor laser (1); an objective lens system (3,4) which converges light emitted from said semiconductor laser on a magneto-optical recording medium; a first diffractive element (85) and a second diffractive element (86) which are sequentially provided between said semiconductor laser and said objective lens system, said first diffractive element having diffraction efficiency not dependent on a polarization direction of incident light and said second diffractive element having diffraction efficiency dependent on the polarization direction of incident light; a first photodetecting means (89,90) receiving light which is reflected from said magneto-optical recording medium, transmitted through said second diffractive element, and then diffracted by said first diffractive element; a second photodetecting means (87,88) receiving light which is reflected from said magneto-optical recording medium and then diffracted by said second diffractive element; and an analyzing means (52,53) which is provided between said second diffractive element and said second photodetecting means and which splits the diffracted light from said second diffractive element into two polarized components orthogonal to each other, characterized in that said second diffractive element has characteristics with which the polarized component in a particular direction in the incident light is partially diffracted and the polarized component orthogonal thereto is substantially totally diffracted and said second diffractive element is disposed such that the polarization direction of the light emitted from said semiconductor laser coincides with said particular direction, and said analyzing means is disposed such that said two polarized components split thereby make an angle of about 45° with respect to the polarization direction of the light emitted from said semiconductor laser.
Claim 6
Dependent Claim
18 words
The magneto-optical head device according to claim 5, in which said analyzing means includes polarizing beam splitters (52,53).
Claim 7
Dependent Claim
45 words
The magneto-optical head device according to claim 6, in which said semiconductor laser (1), said polarizing beam splitters and said photodetecting means are contained in a package (82) and said first diffractive element (85) and said second diffractive element (86) are cemented on said package.
Claim 8
Dependent Claim
18 words
The magneto-optical head device according to claim 5, in which said analyzing means includes polarizing simple gratings (109,110).
Claim 9
Dependent Claim
47 words
The magneto-optical head device according to claim 8, in which said semiconductor laser (1) and said photodetecting means (89,90,111,112) are contained in a package (82) and said first diffractive element (85), said second diffractive element (86) and said polarizing simple gratings (109,110) are cemented on said package.