US3917409A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optical apparatus for determining focus
Assignee: Individual
•
Filing: 1972-06-26
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Granted: 1975-11-04
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Expires: 1992-06-26
Abstract
Abstract An apparatus for determining the focus of a lens. The apparatus includes a light beam generating means and means for providing an output signal which indicates the focus of the lens and/or its relation to the position of optimum focus for a lens for an optical system. The means for providing the output signal can be a cylindrical chopper or an oscillating grid. Preferably the light beam generating means and the chopper are positioned in the same physical structure.
Inventors
- 👤 Paul T Kaestner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 02:15
CPC Classifications
G; G01; G01M; G01M11/00; G01M11/02; G01M11/0228; G02; G02B; G02B7/00; G02B7/28; G02B7/30; G02B7/32
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
199 words
A device for determining the position of optimum focus and the focus of an optical member; light beam transmitter means, for transmitting a beam of light substantially perpendicular to the optical axis of the optical member, having an object plane; deflection means for deflecting a portion of the beam of light so that it travels along the axis of the optical member and through the optical member; a mirror positioned along the optical axis for reflecting said portion of light back through the optical member; receiving means having a target image plane including: means comprising a grid member having alternating slots and bars, movable in a path substantially transverse to the optical axis of the optical member, to provide an output signal including a repeated fluctuating light flux pattern having a phase corresponding to the focus of the optical member and to the direction of the optical member is displaced from the predetermined point of optimum focus; said transmitter means being fixed in position with respect to the receiving means and with respect to the object and target image planes of the transmitter and receiving means, and positioned on the same side of the lens as the receiving means.
Claim 2
Independent Claim
199 words
A device for determining the position of optimum focus and the focus of an optical member; light beam transmitter means, for transmitting a beam of light substantially perpendicular to the optical axis of the optical member, having an object plane; deflection means for deflecting a portion of the beam of light so that it travels along the axis of the optical member and through the optical member; a mirror positioned along the optical axis for reflecting said portion of light back through the optical member; receiving means having a target image plane including: means comprising a grid member having alternating slots and bars, movable in a path substantially transverse to the optical axis of the optical member, to provide an output signal including a repeated fluctuating light flux pattern having a phase corresponding to the focus of the optical member and to the direction of the optical member is displaced from the predetermined point of optimum focus; said transmitter means being fixed in position with respect to the receiving means and with respect to the object and target image planes of the transmitter and receiving means, and positioned on the same side of the lens as the receiving means.
Claim 3
Dependent Claim
23 words
The device as defined by claim 1, wherein said light beam transmitting means and said receiving means are positioned within the same housing.
Claim 4
Dependent Claim
39 words
The combination as defined by claim 1, wherein said transmitter means has an optical axis and said receiving means has an optical axis and said axes being positioned at an angle of less than 180*with respect to each other.
Claim 5
Dependent Claim
12 words
The device as defined by claim 3 wherein said angle is 90*.
Claim 6
Dependent Claim
25 words
The device as defined by claim 1 including, means responsive to the output signal for repositioning said optical member to a point of optimum focus.
Claim 7
Dependent Claim
64 words
The combination as defined by claim 5 said receiver means comprising means for providing a variable signal depending on the position of said optical member, means for providing a fixed reference signal stabilized with respect to the remainder of said last mentioned means so as to not require constant calibration, means for comparing said reference and the variable signal to provide said output signal.
Claim 8
Dependent Claim
49 words
The combination as defined by claim 1 including a right angular reflecting means said latter means being positioned proximate said oscillating grid to reflect a portion of said light beam which passes through said grid member to cause said portion of the beam to travel back through said grid.
Claim 9
Dependent Claim
13 words
The device of claim 1 wherein said deflection means comprises a beam splitter.
Claim 10
Dependent Claim
78 words
The combination as defined by claim 8 wherein said means comprising a grid member having slots and bars movable in a path oscillates across a path and wherein said receiving means includes a right angular reflecting means, said latter means is positioned proximate said oscillating grid to reflect said portion of the beam of light which is emitted from said transmitting means and subsequently passes through said grid to cause the beam to travel back through said grid.
Claim 11
Dependent Claim
16 words
The device of claim 1 wherein the member having slots and bars comprises an oscillating grid.
Claim 12
Dependent Claim
16 words
The device of claim 1 wherein the member having slots and bars comprises a rotating chopper.
Claim 13
Dependent Claim
31 words
The device of claim 1 wherein the light beam after passing through the lens, passes through the means comprising a member having slots and bars twice in forming an output signal.
Claim 14
Dependent Claim
90 words
The combination comprising optical means for focusing an image and means for providing an output signal indicating the direction the optical means is displaced from a point of optimum focus, said means for providing an output signal comprising an oscillating grid for providing a repeated fluctuating light flux pattern having a phase corresponding to the focus of the optical means and to the direction the optical means is displaced from said predetermined point of optimum focus, said grid comprising a flat member having a number of slots and bars thereon.
Claim 15
Dependent Claim
90 words
The combination comprising optical means for focusing an image and means for providing an output signal indicating the direction the optical means is displaced from a point of optimum focus, said means for providing an output signal comprising an oscillating grid for providing a repeated fluctuating light flux pattern having a phase corresponding to the focus of the optical means and to the direction the optical means is displaced from said predetermined point of optimum focus, said grid comprising a flat member having a number of slots and bars thereon.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-11-03 | 1979-05-05 | 1979-11-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-03 | 1983-05-05 | 1983-11-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-03 | 1987-05-05 | 1987-11-04 | $7700.00 | Window Closed / Lapsed |