US4750819A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Anamorphic prism
Assignee: Sony Corp
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Filing: 1986-09-05
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Granted: 1988-06-14
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Expires: 2006-09-05
Abstract
Abstract This invention relates to an anamorphic prism (11) for correcting an anisotropy of a radiation angle of a beam (14). The anamorphic prism (11) is constituted by a first prism (12) and a second prism (13) so that tha anamorphic prism (11) can have an achromatic structure. Refractive indexes and refractive index changes due to a wavelength fluctuation of the first and second prisms (12, 13), and an incident angle of the beam (14) to the first prism (12) can satisfy a predetermined relationship, and the beam (14) can be emerged from the second prism (13) at an exit angle of 0°. The anamorphic prism of this invention can be applied to an optical head or the like using a semiconductor laser as a light source.
Inventors
- 👤 Mikio Sugiki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 11:56
CPC Classifications
G; G02; G02B; G02B27/00; G02B13/00; G02B13/08; G02B13/10; G02B19/00; G02B19/0004; G02B19/0028; G02B19/0033; G02B19/0047; G02B19/0052; G02B27/09; G02B27/0938; G02B27/095; G02B27/0972; G02B5/00; G02B5/04; G11; G11B; G11B7/00; G11B7/12; G11B7/135; G11B7/1356; G11B7/1372; G11B2007/13727
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
183 words
An anamorphic prism comprising: a first prism which has a refractive index of n 1 , a refractive index change of Δn 1 due to a wavelength fluctuation, and a vertex angle of θ 1 , and a second prism which has the refractive index of n 2 , the refractive index change of Δn 2 , and a vertex angle of θ 2 , and is bonded to said first prism, wherein if an incident angle on the second prism of a beam that is incident on the first prism at an incident angle φ 1 is given as φ 2 , when the incident angle φ 2 is less then the vertex angle φ 1 , said first and second prisms and the incident angle φ 1 satisfy: (Δn.sub.2 /Δn.sub.1)·(n.sub.1 /.sub.2)>n.sub.1.sup.2 /(n.sub.1.sup.2 -sin.sup.2 φ.sub.1) when the incidence angle φ 2 is greater than the vertex angle θ 1 , they satisfy: (Δn.sub.2 /Δn.sub.1)·(n.sub.1 /n.sub.2)<n.sub.1.sup.2 /(n.sub.1.sup.2 -sin.sup.2 φ.sub.1) and, the beam is emerged from said second prism at an exit angle of 0° with respect to the vertex angle θ 2 .
Claim 2
Dependent Claim
183 words
An anamorphic prism comprising: a first prism which has a refractive index of n 1 , a refractive index change of Δn 1 due to a wavelength fluctuation, and a vertex angle of θ 1 , and a second prism which has the refractive index of n 2 , the refractive index change of Δn 2 , and a vertex angle of θ 2 , and is bonded to said first prism, wherein if an incident angle on the second prism of a beam that is incident on the first prism at an incident angle φ 1 is given as φ 2 , when the incident angle φ 2 is less then the vertex angle φ 1 , said first and second prisms and the incident angle φ 1 satisfy: (Δn.sub.2 /Δn.sub.1)·(n.sub.1 /.sub.2)>n.sub.1.sup.2 /(n.sub.1.sup.2 -sin.sup.2 φ.sub.1) when the incidence angle φ 2 is greater than the vertex angle θ 1 , they satisfy: (Δn.sub.2 /Δn.sub.1)·(n.sub.1 /n.sub.2)<n.sub.1.sup.2 /(n.sub.1.sup.2 -sin.sup.2 φ.sub.1) and, the beam is emerged from said second prism at an exit angle of 0° with respect to the vertex angle θ 2 .
Claim 3
Dependent Claim
35 words
An anamorphic prism according to claim 1, characterized in that said anamorphic prism is applied to an optical head having a semiconductor laser as a light source, the beam being emitted from said semiconductor laser.
References Cited (Backward Citations)
US4017160A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-06-14 | 1991-12-14 | 1992-06-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-06-14 | 1995-12-14 | 1996-06-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-06-14 | 1999-12-14 | 2000-06-14 | $7700.00 | Window Closed / Lapsed |