GB1472454A - Method for determining the position of a focussing plane - Google Patents
Method for determining the position of a focussing planeInfo
- Publication number
- GB1472454A GB1472454A GB2602674A GB2602674A GB1472454A GB 1472454 A GB1472454 A GB 1472454A GB 2602674 A GB2602674 A GB 2602674A GB 2602674 A GB2602674 A GB 2602674A GB 1472454 A GB1472454 A GB 1472454A
- Authority
- GB
- United Kingdom
- Prior art keywords
- lens
- detectors
- image
- plane
- section
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B7/00—Mountings, adjusting means, or light-tight connections, for optical elements
- G02B7/28—Systems for automatic generation of focusing signals
- G02B7/34—Systems for automatic generation of focusing signals using different areas in a pupil plane
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
- G02B27/40—Optical focusing aids
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
- G02B27/42—Diffraction optics, i.e. systems including a diffractive element being designed for providing a diffractive effect
- G02B27/46—Systems using spatial filters
-
- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09B—EDUCATIONAL OR DEMONSTRATION APPLIANCES; APPLIANCES FOR TEACHING, OR COMMUNICATING WITH, THE BLIND, DEAF OR MUTE; MODELS; PLANETARIA; GLOBES; MAPS; DIAGRAMS
- G09B21/00—Teaching, or communicating with, the blind, deaf or mute
- G09B21/001—Teaching or communicating with blind persons
- G09B21/003—Teaching or communicating with blind persons using tactile presentation of the information, e.g. Braille displays
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Engineering & Computer Science (AREA)
- Business, Economics & Management (AREA)
- General Health & Medical Sciences (AREA)
- Audiology, Speech & Language Pathology (AREA)
- Health & Medical Sciences (AREA)
- Educational Administration (AREA)
- Educational Technology (AREA)
- Theoretical Computer Science (AREA)
- Measurement Of Optical Distance (AREA)
- Length Measuring Devices By Optical Means (AREA)
Abstract
1472454 Photoelectric focus detection ERNST LEITZ WETZLAR GmbH 12 June 1974 [18 June 1973] 26026/74 Heading H4D To determine when an image produced by a lens 1, Fig. 1 is in a required plane, a special frequency filter 2 is positioned in and vibrated in the plane in a direction at right-angles to the divisions of the filter. The contributions 4a<SP>1</SP> and 4a<SP>111</SP> to the image by two spaced sections 1<SP>1</SP> and 1<SP>111</SP> of the lens are detected by respective photoelectric detectors 5. The movement of the filter 2 produces alternating outputs from the two detectors which are in phase if the image is in said plane. Due however to the lateral spacing of the lens sections 1<SP>1</SP> and 1<SP>111</SP>, a "parallax" effect is produced between the two part images falling on the detectors, such that when the image is not in said plane the outputs are out of phase, the sense of the plane difference being indicative of the sense of deviation of the image from the plane. To overcome spurious signals being generated by brightness variations across the image, the filter is in the form of a plurality of prisms having alternate faces 21, 22 which diffract to give two images 4a and 4b both modulated and both having an associated pair of photodetectors 5. Suitable sum and difference combinations Fig. 2 (not shown), of the outputs of the detectors produces an accentuation of the phase varying alternating signals and the cancellation of the spurious signals. A light stop may be incorporated in a prism arrangement in front of each pair of detectors to block off the light from the central strip section 1<SP>11</SP> of the lens as well as directing (refracting) the two part images on to the respective detectors, Fig. 3 (not shown). The lens 1 may provide a plurality of pairs of spaced sections, either linear or semiannular (Figs. 4 and 6, not shown), to give wide base line and narrow base line systems for simultaneous large and small distance measurements respectively. The central section of the lens may be used to give an object movement (parallel to the oscillatory direction of the filter) indication. A zone plate 9, Fig. 8 (details Fig. 9) may be placed in front of the lens 1 to co-operate with three lenses 3a, 3b, 3c in dividing the image into two outer sections 2a, 2b and a middle section 2b, the section 2b including a sub-section 2e. The middle section image 2b is focussed by lens 3b on to two pairs of detectors 5 corresponding to the two pairs of detectors in Fig. 1 and corresponding to an object at a near distance Y. The sub-section image 2e is detected by detectors 5c, 5b and gives velocity information at far distance X. Outer detectors with lenses 3a, 3b give focussing information corresponding to the object at distance X. An aid for a blind person, Fig. 15b incorporates a horizontally directed system using lens 1 with zone plate 9a to give detection of obstacles at two distances and a downwardly directed system using lens 1a and zone plate 9b for floor obstacles, e.g. steps, at two distances, a light source 16 being used for night use. The outputs of the systems are communicated to vibrators actuating buttons 14a-14g, for tactile finger sensing. The lens 1 may provide for spaced sections 1<SP>1</SP>-1<SP>v</SP>, Fig. 15 with the image being circularly scanned over a fixed pyramidal grating 12 by a rotating optical wedge 11. Four pairs of detectors can then be used giving increased accuracy.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE19732330940 DE2330940C3 (en) | 1973-06-18 | Method and device for photoelectrically determining the position of at least one focal plane of an image |
Publications (1)
Publication Number | Publication Date |
---|---|
GB1472454A true GB1472454A (en) | 1977-05-04 |
Family
ID=5884325
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB2602674A Expired GB1472454A (en) | 1973-06-18 | 1974-06-12 | Method for determining the position of a focussing plane |
Country Status (7)
Country | Link |
---|---|
CA (1) | CA1009072A (en) |
CH (1) | CH601773A5 (en) |
FR (1) | FR2233640B1 (en) |
GB (1) | GB1472454A (en) |
IT (1) | IT1011983B (en) |
NL (1) | NL182100C (en) |
SE (1) | SE399126B (en) |
Families Citing this family (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2315706A1 (en) * | 1975-06-26 | 1977-01-21 | Leitz Ernst Gmbh | METHOD AND DEVICE FOR AUTOMATIC FOCUSING OF AN OPTICAL APPARATUS INCLUDING A DETECTION NETWORK |
DE2813905A1 (en) * | 1977-04-05 | 1978-10-12 | Georges Ducommun | AID DEVICE FOR DETECTING THE SURROUNDINGS BY THE BLIND OR VISUALLY IMPAIRED PERSONS |
DE3039425A1 (en) * | 1980-10-18 | 1982-05-19 | Ernst Leitz Wetzlar Gmbh, 6330 Wetzlar | DEVICE FOR PHOTOELECTRICALLY DETERMINING THE POSITION OF AT LEAST ONE FOCUS OF AN IMAGE |
US4310227A (en) * | 1981-01-05 | 1982-01-12 | Polaroid Corporation | Diffracted energy auto-ranging system for a camera |
DE3233013A1 (en) * | 1982-09-06 | 1984-03-08 | Siemens AG, 1000 Berlin und 8000 München | OPTICAL ARRANGEMENT FOR DETECTING AND EVALUATING THE LOCATION OF AN OBJECT |
DE3706286A1 (en) * | 1987-02-26 | 1988-09-08 | Friedrich Horst Ing Papenmeier | ELECTROMECHANICAL BRAILLE LINE |
-
1974
- 1974-06-12 GB GB2602674A patent/GB1472454A/en not_active Expired
- 1974-06-17 IT IT68892/74A patent/IT1011983B/en active
- 1974-06-17 SE SE7407984A patent/SE399126B/en not_active IP Right Cessation
- 1974-06-17 CA CA202,631A patent/CA1009072A/en not_active Expired
- 1974-06-17 CH CH827374A patent/CH601773A5/xx not_active IP Right Cessation
- 1974-06-17 FR FR7421001A patent/FR2233640B1/fr not_active Expired
- 1974-06-18 NL NLAANVRAGE7408136,A patent/NL182100C/en not_active IP Right Cessation
Also Published As
Publication number | Publication date |
---|---|
CA1009072A (en) | 1977-04-26 |
SE399126B (en) | 1978-01-30 |
DE2330940B2 (en) | 1976-01-02 |
CH601773A5 (en) | 1978-07-14 |
NL7408136A (en) | 1974-12-20 |
IT1011983B (en) | 1977-02-10 |
DE2330940A1 (en) | 1975-01-02 |
NL182100C (en) | 1988-01-04 |
FR2233640B1 (en) | 1978-11-17 |
SE7407984L (en) | 1974-12-19 |
FR2233640A1 (en) | 1975-01-10 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US4071297A (en) | Method and apparatus for photoelectrically determining the position of at least one image focus plane | |
US4079252A (en) | Photoelectric grating displacement measuring apparatus | |
US4148587A (en) | Laser gauge for measuring changes in the surface contour of a moving part | |
FR2428271A1 (en) | DISTANCE DETECTION APPARATUS | |
US3599004A (en) | Arrangement of photocells for the determination of the position of an equidistantly divided scale | |
US3856400A (en) | Apparatus for no-contact measurement having a multi-colored grating | |
US3906220A (en) | Optical correlator | |
FR2434367A1 (en) | INCREMENTAL PHOTOELECTRIC DEVICE FOR MEASURING LENGTHS AND ANGLES | |
GB1472454A (en) | Method for determining the position of a focussing plane | |
EP0553181B1 (en) | Position fixing | |
US4040741A (en) | Polarized grating optical odometer | |
US4220406A (en) | Optical electronic focusing device | |
GB1510836A (en) | Apparatus for testing the degree of correlation between two individual images | |
GB1383320A (en) | Measurement of the shape of strip material | |
JPS6232403B2 (en) | ||
DE3679606D1 (en) | POSITION MEASURING DEVICE WITH OPTICAL GRIDS. | |
SU1049735A1 (en) | Method and apparatus for measuring angle displacement of object in two biperpendicular planes | |
EP0382564A3 (en) | Focus state detecting device | |
SU669202A1 (en) | Loose material level meter | |
SU1730538A1 (en) | Device for measuring displacement of the edge of non- transparent object | |
JPH0411807B2 (en) | ||
SU577555A1 (en) | Photoelectric tape speed sensor | |
SU838326A1 (en) | Method of checking microobject linear dimensions | |
SU1276905A1 (en) | Photoelectric displacement transducer | |
SU998857A1 (en) | Indexing machine drive control device |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PS | Patent sealed | ||
PCNP | Patent ceased through non-payment of renewal fee |
Effective date: 19920612 |