US4215924A
Expired / Lapsed
US
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Method to control introduction of diffracted beam by means of diffraction element
Assignee: Canon Inc
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Filing: 1978-09-29
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Granted: 1980-08-05
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Expires: 1998-09-29
Abstract
Abstract According to the present invention in the image forming light path a direction-selective diffraction element is provided in such a manner that the image forming beam having entered into said diffraction element is diffracted by means of the diffraction grating structure of said diffraction element and devided into a plurality of beams, whereby at least one of the diffracted beams is led to a photo detecting device while the not diffracted beam is made use of as the image forming beam.
Inventors
- 👤 Kazuya Matsumoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 18:50
CPC Classifications
G; G02; G02B; G02B27/00; G02B27/10; G02B27/14; G02B27/144; G02B27/108; G02B27/1086; G02B5/00; G02B5/32; G03; G03B; G03B19/00; G03B19/02; G03B19/12; G03B7/00; G03B7/08; G03B7/099; G03B7/0993; G03B7/0997; G03B7/09971; G03B7/09973; G03B7/09974; G03B7/09976
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
156 words
A method for measuring varying intensities of light comprising: exposing an image forming optical system to the varying intensities of light and directing the light along an optical path within the system; receiving the varying light by one of two flat faces of a planar optical system having an end face; intercepting at least a section of the varying light in the path with a diffraction element whose size within the path of the light remains constant; diffracting the light incident on the diffraction element out of the optical path so that at least a portion of the diffracted light reaches one of the flat faces of the planar optical system at a total reflection angle; internally reflecting the diffracted light by the flat faces toward said end face; and receiving the diffracted light projected from the end face by light detecting means; said intercepting step including orienting the element substantially perpendicular to the optical path.
Claim 2
Independent Claim
156 words
A method for measuring varying intensities of light comprising: exposing an image forming optical system to the varying intensities of light and directing the light along an optical path within the system; receiving the varying light by one of two flat faces of a planar optical system having an end face; intercepting at least a section of the varying light in the path with a diffraction element whose size within the path of the light remains constant; diffracting the light incident on the diffraction element out of the optical path so that at least a portion of the diffracted light reaches one of the flat faces of the planar optical system at a total reflection angle; internally reflecting the diffracted light by the flat faces toward said end face; and receiving the diffracted light projected from the end face by light detecting means; said intercepting step including orienting the element substantially perpendicular to the optical path.
Claim 3
Dependent Claim
38 words
A method as in claim 1, wherein the image forming optical system is composed of a plurality of optical elements and the diffracting step is performed as light emerges from one element before it enters the other element.
Claim 4
Dependent Claim
22 words
A method as in claim 1, wherein the diffraction step is performed after the light emerges from the image forming optical system.
Claim 5
Dependent Claim
26 words
A method as in claim 1, wherein the image forming optical system defines a focal plane and the diffraction step is performed on the focal plane.
Claim 6
Dependent Claim
30 words
A method as in claim 1, wherein the image forming optical system defines a focal plane and the diffraction step is performed in the optical path beyond the focal plane.
Claim 7
Independent Claim
115 words
A method for measuring portions of the light incident on an image forming optical system, comprising: forming an optical path with a portion of the system; intercepting at least a section of the light in the path with a transparent element having a plurality of diffracting parts each formed of a diffraction lattice whose size within the path of the light remains constant; diffracting the intercepted light in a plurality of directions separately of each other in accordance with each of said diffracting parts; and measuring the diffracted lights separately, by means of light detecting means, in each of the different directions, said intercepting step including orienting the element substantially perpendicular to the optical path.
Claim 8
Independent Claim
115 words
A method for measuring portions of the light incident on an image forming optical system, comprising: forming an optical path with a portion of the system; intercepting at least a section of the light in the path with a transparent element having a plurality of diffracting parts each formed of a diffraction lattice whose size within the path of the light remains constant; diffracting the intercepted light in a plurality of directions separately of each other in accordance with each of said diffracting parts; and measuring the diffracted lights separately, by means of light detecting means, in each of the different directions, said intercepting step including orienting the element substantially perpendicular to the optical path.
Claim 9
Dependent Claim
33 words
A method as in claim 6, wherein the step of diffracting the intercepted light includes diffracting the light in a plurality of directions at different diffraction rates with each of said diffracting parts.
Claim 10
Dependent Claim
28 words
The method as in claim 6, wherein the diffraction step includes diffracting at least a part of the light so as to produce convergence with the diffraction lattice.
Claim 11
Dependent Claim
24 words
A method as in claim 6, wherein said diffracting parts consist of a first part and a second part completely surrounding the first part.
Claim 12
Dependent Claim
123 words
A light guide comprising: a transparent plate having two flat faces and an end face forming a projection face, and a diffraction lattice formed on the transparent plate for diffracting light incident upon the transparent plate toward one of the two flat faces so that at least a portion of the diffracted light reaches the one of the two flat faces at a total reflection angle and so that the diffracted light is internally reflected toward the end face, said lattice covering an area less than the area of one of the faces and being surrounded on all sides within one of the faces by a non-diffracting surface and having an area less than the cross section of light to be directed thereon.
Claim 13
Dependent Claim
123 words
A light guide comprising: a transparent plate having two flat faces and an end face forming a projection face, and a diffraction lattice formed on the transparent plate for diffracting light incident upon the transparent plate toward one of the two flat faces so that at least a portion of the diffracted light reaches the one of the two flat faces at a total reflection angle and so that the diffracted light is internally reflected toward the end face, said lattice covering an area less than the area of one of the faces and being surrounded on all sides within one of the faces by a non-diffracting surface and having an area less than the cross section of light to be directed thereon.
Claim 14
Dependent Claim
117 words
A light guide comprising: a parallel planar plate having an end face, and a diffraction lattice formed on the parallel planar plate, said diffraction lattice forming an angle at least other than a total reflection angle to the plane of the plate, and diffracting the incident light at least to one of the parallel planes at a total reflection angle and projecting the diffracted light which was totally reflected from the end face, said lattice covering an area less than the area of one of the faces and being surrounded on all sides within one of the faces by a non-diffracting surface and having an area less than the cross section of light to be directed thereon.
Claim 15
Dependent Claim
117 words
A light guide comprising: a parallel planar plate having an end face, and a diffraction lattice formed on the parallel planar plate, said diffraction lattice forming an angle at least other than a total reflection angle to the plane of the plate, and diffracting the incident light at least to one of the parallel planes at a total reflection angle and projecting the diffracted light which was totally reflected from the end face, said lattice covering an area less than the area of one of the faces and being surrounded on all sides within one of the faces by a non-diffracting surface and having an area less than the cross section of light to be directed thereon.
Claim 16
Dependent Claim
113 words
A light guide comprising: a parallel planar sheet having parallel faces and an end face, and a diffraction lattice on said parallel planar sheet, said diffraction lattice directing the light incident on one of the parallel faces at a non-total reflection angle toward the other parallel face at a total reflection angle and projecting the light totally reflected by the other parallel face from one of the parallel faces, said lattice covering an area less than the area of one of the faces and being surrounded on all sides within one of the faces by a non-diffracting surface and having an area less than the cross section of light to be directed thereon.
Claim 17
Dependent Claim
113 words
A light guide comprising: a parallel planar sheet having parallel faces and an end face, and a diffraction lattice on said parallel planar sheet, said diffraction lattice directing the light incident on one of the parallel faces at a non-total reflection angle toward the other parallel face at a total reflection angle and projecting the light totally reflected by the other parallel face from one of the parallel faces, said lattice covering an area less than the area of one of the faces and being surrounded on all sides within one of the faces by a non-diffracting surface and having an area less than the cross section of light to be directed thereon.
Claim 18
Independent Claim
129 words
An apparatus for measuring portions of light incident on an image forming optical system, comprising: a diffraction element having a transparent sheet and a diffraction lattice of predetermined size carried by the sheet, said sheet having two flat faces, said lattice being arranged to intercept at least a section of the light of predetermined size and to diffract said intercepted light out of the optical path toward one of the two flat faces at a total reflection angle so that at least a portion of the diffracted light is internally reflected toward said end face, and light detecting means in the direction of at least a portion of the light diffracted from the optical path for measuring at least a portion of the light diffracted from the optical path.
Claim 19
Independent Claim
129 words
An apparatus for measuring portions of light incident on an image forming optical system, comprising: a diffraction element having a transparent sheet and a diffraction lattice of predetermined size carried by the sheet, said sheet having two flat faces, said lattice being arranged to intercept at least a section of the light of predetermined size and to diffract said intercepted light out of the optical path toward one of the two flat faces at a total reflection angle so that at least a portion of the diffracted light is internally reflected toward said end face, and light detecting means in the direction of at least a portion of the light diffracted from the optical path for measuring at least a portion of the light diffracted from the optical path.
Claim 20
Dependent Claim
16 words
An apparatus as in claim 13, wherein the diffraction lattice is formed on the transparent sheet.
Claim 21
Dependent Claim
40 words
An apparatus as in claim 13, wherein said diffraction element includes a plurality of parts having different diffraction directions, said light detecting means including a plurality of measuring means for measuring the light in each of the plurality of directions.
Claim 22
Dependent Claim
20 words
An apparatus as in claim 13, in which the diffraction lattice includes two sections each having a different diffraction rate.
Claim 23
Dependent Claim
19 words
An apparatus as in claim 13, wherein the diffraction lattice is such as to produce a converged diffraction light.
Claim 24
Dependent Claim
87 words
An optical apparatus, comprising: an image forming optical system defining an optical path, a diffraction element of predetermined size in the optical path of the light arranged for diffracting a predetermined part of constant size, of the light incident on the image forming optical system outside of the optical path, and a light detecting means arranged in the direction of light diffracted by said diffraction element for measuring the different light, said element being surrounded by non-diffracting surfaces on all sides lying entirely within said optical path.
Claim 25
Dependent Claim
87 words
An optical apparatus, comprising: an image forming optical system defining an optical path, a diffraction element of predetermined size in the optical path of the light arranged for diffracting a predetermined part of constant size, of the light incident on the image forming optical system outside of the optical path, and a light detecting means arranged in the direction of light diffracted by said diffraction element for measuring the different light, said element being surrounded by non-diffracting surfaces on all sides lying entirely within said optical path.
Claim 26
Dependent Claim
19 words
A light guide as in claim 10, further comrising a plurality of optical fibers emerging from the end face.
References Cited (Backward Citations)
US3458702A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-08-05 | 1984-02-04 | 1984-08-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-08-05 | 1988-02-04 | 1988-08-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-08-05 | 1992-02-04 | 1992-08-05 | $7700.00 | Window Closed / Lapsed |