US4719480A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Spatial stablization of standing capillary surface waves
Assignee: Xerox Corp
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Filing: 1986-04-17
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Granted: 1988-01-12
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Expires: 2006-04-17
Abstract
Abstract Provision is made spatially stabilizing standing capillary surface waves in fixed and repeatable locations with respect to stationary external references. For spatially stabilizing such a wave on the free surface of a volume of liquid, the wave propagation characteristics of the free surface of liquid are periodically varied in a spatially stable manner at a spatial frequency equal to the spatial frequency of the standing wave or a subharmonic thereof, thereby locking the crests and troughs of the standing wave in predetermined spatial locations. A spatially periodic pattern of notches in a wall or base plate bounding the free surface of the liquid may be employed to physically modulate its wave propagation characteristics at a suitable spatial frequency. Alternatively freely propagating secondary capillary surface waves may be launched from spatially periodic sites along the free surface of the liquid to actively modulate its wave propagation characteristics at the diesired spatial frequency.
Inventors
- 👤 Scott A. Elrod
- 👤 Butrus T. Khuri-Yakub
- 👤 Calvin F. Quate
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 18:40
CPC Classifications
B; B41; B41J; B41J2/00; B41J2/005; B41J2/01; B41J2/015; B41J2/04; B41J2/06; B41J2/065; B41J2/135; B41J2/14; B41J2/14008; G; G10; G10K; G10K11/00; G10K11/36; B41J2002/14322
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
81 words
In a combination with a volume of liquid having a free surface, and means for generating a standing capillary wave on said free surface; said capillary wave having a periodic wave structure including crests and troughs; the improvement comprising another means for periodically varying a wave propagation characteristic of said free surface along at least one axis at a spatial frequency selected to cause the the crests of said standing wave to preferentially align at predetermined spatial locations along said axis.
Claim 2
Dependent Claim
81 words
In a combination with a volume of liquid having a free surface, and means for generating a standing capillary wave on said free surface; said capillary wave having a periodic wave structure including crests and troughs; the improvement comprising another means for periodically varying a wave propagation characteristic of said free surface along at least one axis at a spatial frequency selected to cause the the crests of said standing wave to preferentially align at predetermined spatial locations along said axis.
Claim 3
Dependent Claim
30 words
The improvement of claim 1 wherein said other means comprises a plurality of substantially equidistantly separated notches formed in a surface which borders said free surface parallel to said axis.
Claim 4
Dependent Claim
72 words
The improvement of claim 2 wherein said liquid is disposed within an axially elongated acoustic horn having a relatively narrow collar bordering said free surface for confining said wave structure to said predetermined axis, said notches are etched into said collar, and an acoustic transducer means is disposed within said horn for radiating the free surface of said liquid with an ultrasonic pressure wave of sufficient amplitude to generate said standing wave.
Claim 5
Dependent Claim
63 words
The improvement of claim 3 wherein said transducer means is substantially coextensive with said horn along said axis, and said transducer means comprises a plurality of mechanically independent piezoelectric elements which are poled in a direction normal to said free surface, and means for exciting said piezoelectric elements in unison, whereby said pressure wave has a substantially uniform amplitude lengthwise of said horn.
Claim 6
Dependent Claim
39 words
The improvement of claim 3 further including a plurality of discrete addressing elements which are supported by said collar and aligned with respective ones of said notches to selectively address individual ones of said crests in parallel on command.
Claim 7
Dependent Claim
14 words
The improvement of claim 5 wherein said addressing elements are disposed within said notches.
Claim 8
Dependent Claim
27 words
The improvement of claim 6 further including a recording medium disposed adjacent the free surface of said liquid for receiving the droplets freed from the selected crests.
Claim 9
Dependent Claim
50 words
The improvement of claim 7 wherein said transducer means comprises a plurality of mechanically independent piezoelectric elements which are poled in a direction normal to said free surface, and means for exciting said piezoelectric elements in unison, whereby said pressure wave has a substantially uniform amplitude lengthwise of said horn.
Claim 10
Dependent Claim
64 words
The improvement of claim 1 wherein said other means comprises a plurality of capillary wave sources equidistantly separated along a surface which borders said free surface parallel to said axis, and means for spatially modulating said sources at said spatial frequency, thereby causing said sources to generate surface waves for preferentially aligning the crests of said standing wave with respective ones of said sources.
Claim 11
Dependent Claim
72 words
The improvement of claim 9 wherein said liquid is disposed within an axially elongated acoustic horn having a relatively narrow collar bordering said free surface for confining said wave structure to said predetermined axis, said sources are supported on said collar, and an acoustic transducer means is disposed within said horn for radiating the free surface of said liquid with an ultrasonic pressure wave of sufficient amplitude to generate said standing wave.
Claim 12
Dependent Claim
63 words
The improvement of claim 10 wherein said transducer means is substantially coextensive with said horn along said axis, and said transducer means comprises a plurality of mechanically independent piezoelectric elements which are poled in a direction normal to said free surface, and means for exciting said piezoelectric elements in unison, whereby said pressure wave has a substantially uniform amplitude lengthwise of said horn.
Claim 13
Dependent Claim
22 words
The improvement of claim 10 further including discrete addressing means for selectively addressing individual ones of said crests in parallel on command.
Claim 14
Dependent Claim
21 words
The improvement of claim 12 wherein said addressing means comprise means for further modulating said sources as a function of time.
Claim 15
Dependent Claim
27 words
The improvement of claim 13 further including a recording medium disposed adjacent the free surface of said liquid for receiving the droplets freed from the selected crests.
Claim 16
Dependent Claim
50 words
The improvement of claim 14 wherein said transducer means comprises a plurality of mechanically independent piezoelectric elements which are poled in a direction normal to said free surface, and means for exciting said piezoelectric elements in unison, whereby said pressure wave has a substantially uniform amplitude lengthwise of said horn.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-01-11 | 1991-07-13 | 1992-01-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-01-11 | 1995-07-13 | 1996-01-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-01-11 | 1999-07-13 | 2000-01-12 | $7700.00 | Window Closed / Lapsed |