US3814510A
Expired / Lapsed
US
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Method and apparatus for measuring the critical flicker fusion frequency
Assignee: Biviator AG
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Filing: 1972-02-25
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Granted: 1974-06-04
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Expires: 1992-02-25
Abstract
Abstract A method and apparatus for measuring the critical flicker fusion frequency of a person, wherein flickering light pulses are displayed for observation on an area surrounded by a ring-shaped area illuminated by an adaptation light appearing as a constant non-flickering light.
Inventors
- 👤 K Adler
- 👤 G Ducommun
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 16:22
CPC Classifications
A; A61; A61B; A61B5/00; A61B5/16; A61B5/18; A61B5/161
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
82 words
A method for measuring the critical flicker fusion frequency of a person, comprising producing light pulses of variable frequency and displaying them to a person to be tested by means of a flickering illumination appearing in the center of a display screen, and producing and displaying simultaneously a ring of continuous adaptation illumination round said flickering light, on the same display screen, said flickering illumination and said adaptation illumination being displayed separately from each other but without visible boundary zone between them.
Claim 2
Independent Claim
82 words
A method for measuring the critical flicker fusion frequency of a person, comprising producing light pulses of variable frequency and displaying them to a person to be tested by means of a flickering illumination appearing in the center of a display screen, and producing and displaying simultaneously a ring of continuous adaptation illumination round said flickering light, on the same display screen, said flickering illumination and said adaptation illumination being displayed separately from each other but without visible boundary zone between them.
Claim 3
Independent Claim
98 words
An apparatus for measuring the critical flicker fusion frequency of a person, comprising a circular plane display screen, a flickering light source energized by an electronic variable-frequency pulse generator and disposed for display in a central portion of said screen in order to produce a flickering illumination, and an adaptation light source surrounding said flickering light source and energized for producing a continuous adaptation illumination, said adaptation light source disposed for display in a peripheral portion of said screen, wherein said adaptation light source surrounds said flickering light source without interference and without any visible boundary zone therebetween.
Claim 4
Independent Claim
98 words
An apparatus for measuring the critical flicker fusion frequency of a person, comprising a circular plane display screen, a flickering light source energized by an electronic variable-frequency pulse generator and disposed for display in a central portion of said screen in order to produce a flickering illumination, and an adaptation light source surrounding said flickering light source and energized for producing a continuous adaptation illumination, said adaptation light source disposed for display in a peripheral portion of said screen, wherein said adaptation light source surrounds said flickering light source without interference and without any visible boundary zone therebetween.
Claim 5
Dependent Claim
17 words
An apparatus according to claim 2, comprising means for varying the intensity of the adaptation light source.
Claim 6
Dependent Claim
24 words
An apparatus according to claim 2, comprising a flickering light source of low inertia and a rectangular-pulse generator for energizing said flickering light source.
Claim 7
Dependent Claim
28 words
An apparatus according to claim 4, wherein said pulse generator includes a means allowing adjustment of a variable ratio between the duration of pulses and pulse intervals respectively.
Claim 8
Dependent Claim
25 words
An apparatus according to claim 4, wherein said pulse former includes logical means for preselection of all ratios between entire numbers beTween 1:99 and 99:1.
Claim 9
Dependent Claim
14 words
An apparatus according to claim 2, comprising means for preselection of the pulse amplitude.
Claim 10
Dependent Claim
40 words
An apparatus according to claim 2, having a rotatable adjusting member for the generator frequency, and comprising a disengageable locking mechanism allowing rotation of said adjusting member in the sense of decreasing frequencies only if said locking mechanism is engaged.
Claim 11
Independent Claim
136 words
An apparatus for measuring the critical flicker fusion frequency of a person, comprising a flickering light source energized by a variable-frequency pulse generator in order to produce a flickering illumination, and an adaptation light source surrounding said flickering light source and energized for producing a continuous adaptation illumination, said flickering illumination and said continuous adaptation illumination being accommodated in a common illumination unit having a cylindrical casing including a back and an opal disc at its front side, a space enclosed within said casing between said back and opal disc being subdivided by a thin opaque partition wall extending from said back to said disc into concentric compartments, a flash illumination of said flickering light source being located in the inner of said compartments while means for continuous illumination are located in the outer annular compartment.
Claim 12
Independent Claim
136 words
An apparatus for measuring the critical flicker fusion frequency of a person, comprising a flickering light source energized by a variable-frequency pulse generator in order to produce a flickering illumination, and an adaptation light source surrounding said flickering light source and energized for producing a continuous adaptation illumination, said flickering illumination and said continuous adaptation illumination being accommodated in a common illumination unit having a cylindrical casing including a back and an opal disc at its front side, a space enclosed within said casing between said back and opal disc being subdivided by a thin opaque partition wall extending from said back to said disc into concentric compartments, a flash illumination of said flickering light source being located in the inner of said compartments while means for continuous illumination are located in the outer annular compartment.
Claim 13
Dependent Claim
15 words
An apparatus according to claim 9, wherein said flash illumination is a spiral-shaped flash tube.
Claim 14
Dependent Claim
18 words
An apparatus according to claim 9, wherein said means for continuous illumination comprise a ring of incandescent lamps.
Claim 15
Independent Claim
126 words
An apparatus for measuring the critical flicker fusion frequency of a person, comprising a flickering light source energized by an electronic variable-frequency pulse generator in order to produce a flickering illumination, and an adaptation light source surrounding said flickering light source and energized for producing a continuous adaptation illumination, said flickering illumination and said continuous adaptation illumination being accommodated in a common illumination unit having a casing including an opal disc at its front side, a space enclosed within said casing inside said opal disc, this space being subdivided into concentric compartments by opaque partition means extending from said disc, said flickering light source being located in the inner of said compartments and said means for continuous adaptation illumination being located in the outer annular compartment.
Claim 16
Independent Claim
126 words
An apparatus for measuring the critical flicker fusion frequency of a person, comprising a flickering light source energized by an electronic variable-frequency pulse generator in order to produce a flickering illumination, and an adaptation light source surrounding said flickering light source and energized for producing a continuous adaptation illumination, said flickering illumination and said continuous adaptation illumination being accommodated in a common illumination unit having a casing including an opal disc at its front side, a space enclosed within said casing inside said opal disc, this space being subdivided into concentric compartments by opaque partition means extending from said disc, said flickering light source being located in the inner of said compartments and said means for continuous adaptation illumination being located in the outer annular compartment.
References Cited (Backward Citations)
US3424519A
Cited
US3600067A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-06-03 | 1977-12-03 | 1978-06-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-03 | 1981-12-03 | 1982-06-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-03 | 1985-12-03 | 1986-06-04 | $7700.00 | Window Closed / Lapsed |