← Back to Patent Explorer
US4997261A Expired / Lapsed US ⏱️ 0.0 years remaining

Optical beam splitter

Assignee: Think Laboratory Co Ltd
•
Filing: 1989-06-13
•
Granted: 1991-03-05
•
Expires: 2009-06-13
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract An optical beam splitter which splits a single light into a plurality of split beams including a plurality of transparent plates of uniform thickness arranged in a stack with fully reflective films coated on the transparent plates at both ends of the stack and semi-reflective films coated on the remaining transparent plates in the stack. The reflectivities of the individual semi-reflective films gradually increase from one end to the other in the stack and a beam entering the stack is first entirely reflected by the back-end fully reflective film, then passes through the semi-reflective films while being reflected partially by the semi-reflective films, and then finally entirely reflected by the front-end fully reflective film so that a single beam is split into a plurality of parallel split beams.

Inventors

  • 👤 Hiroshi Taniura

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-24 17:43
CPC Classifications
G; G02; G02B; G02B27/00; G02B27/10; G02B27/14; G02B27/142

Claims Analysis

Total Claims: 3
Claim 1
Independent Claim 187 words
An optical beam splitter comprising: a plurality of n (n=integer) transparent plates of uniform thickness to a high degree of precision assembled in a stack; a plurality of fully reflective films provided on the surfaces of said transparent plates which are at both ends of said stack; and a plurality of semi-reflective films provided on the surfaces of adjacent transparent plates in the stack, reflectivities of said semi-reflective films gradually increasing from the plate at the back end of said stack toward front-end of said stack in a numerical series 1/n, 1/(n-1), 1/(n-2), . . . 1/4, 1/3, and 1/2, and said fully reflective films and semi-reflective films being arranged such that a light beam entering said stack of transparent plates at a prescribed angle from one end of said stack is first entirely reflected by said back-end fully reflective film and then passes through said semi-reflective films to be entirely reflected by said front-end fully reflective film so that split light beams which said light beam is split into while passing through said semi-reflective films and said fully reflective film are reflected out of said stack.
Claim 2
Dependent Claim 187 words
An optical beam splitter comprising: a plurality of n (n=integer) transparent plates of uniform thickness to a high degree of precision assembled in a stack; a plurality of fully reflective films provided on the surfaces of said transparent plates which are at both ends of said stack; and a plurality of semi-reflective films provided on the surfaces of adjacent transparent plates in the stack, reflectivities of said semi-reflective films gradually increasing from the plate at the back end of said stack toward front-end of said stack in a numerical series 1/n, 1/(n-1), 1/(n-2), . . . 1/4, 1/3, and 1/2, and said fully reflective films and semi-reflective films being arranged such that a light beam entering said stack of transparent plates at a prescribed angle from one end of said stack is first entirely reflected by said back-end fully reflective film and then passes through said semi-reflective films to be entirely reflected by said front-end fully reflective film so that split light beams which said light beam is split into while passing through said semi-reflective films and said fully reflective film are reflected out of said stack.
Claim 3
Dependent Claim 21 words
A optical beam splitter according to claim 1, wherein said stack of transparent plates are sandwiched between two additional transparent plates.

References Cited (Backward Citations)

US2403731A Cited
JPS52122135A Cited
US4367921A Cited
JPS5810713A Cited
US4627688A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1994-03-04 1994-09-03 1995-03-05 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1998-03-04 1998-09-03 1999-03-05 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2002-03-04 2002-09-03 2003-03-05 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag