Patent US4754289A successfully refreshed from Google Patents.
US4754289A
Expired / Lapsed
US
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Two-dimensional ink drop shadow position detecting apparatus
Assignee: Fujifilm Business Innovation Corp
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Filing: 1986-07-09
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Granted: 1988-06-28
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Expires: 2006-07-09
Abstract
Abstract A two-dimensional position detecting apparatus for ink drops is disclosed including a light source and a pair of photodetectors disposed in a detecting region so that the pair of photodetectors respectively produce electrical signals in accordance with a flying position of the ink drops in the detecting region, and a signal processor for detecting a horizontal position of the ink drops on the basis of a difference in an output signal between the photodetectors and for detecting a vertical position of the same ink drops on the basis of the sum of the respective output signals of the pair of photodetectors.
Inventors
- 👤 Osami Kudo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 08:05
CPC Classifications
B; B41; B41J; B41J2/00; B41J2/005; B41J2/01; B41J2/07; B41J2/125; G; G01; G01D; G01D15/00; G01D15/16; G01D15/18
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
223 words
In an ink jet system recording apparatus comprising at least one nozzle so that recording is performed while controlling charges on ink drops discharged from said nozzle, a two-dimensional position detecting apparatus for ink drops comprising: a single light source means and a pair of photodetector means disposed in a detecting region; said pair of photodetector means being sufficiently close that a single ink drop, passing in a space between said single light source and said pair of photodetector means, can cast a shadow simultaneously upon said pair of photodetector means; the ink drop casting a shadow having a size in proportion to the proximity of the ink drop to said single light source means; said pair of photodetector means respectively producing electrical signals corresponding to light falling on said pair of photodetector means from said single light source means; the amount of light falling upon said pair of photodetector means being affected by a flying position of said ink drops in said detecting region; and a single processing means for detecting a horizontal position of an ink drop on the basis of a difference in said electrical signals between said pair of photodetector means, and for detecting a vertical position of the same ink drop on the basis of the sum of said respective electrical signals of said pair of photodetector means.
Claim 2
Dependent Claim
223 words
In an ink jet system recording apparatus comprising at least one nozzle so that recording is performed while controlling charges on ink drops discharged from said nozzle, a two-dimensional position detecting apparatus for ink drops comprising: a single light source means and a pair of photodetector means disposed in a detecting region; said pair of photodetector means being sufficiently close that a single ink drop, passing in a space between said single light source and said pair of photodetector means, can cast a shadow simultaneously upon said pair of photodetector means; the ink drop casting a shadow having a size in proportion to the proximity of the ink drop to said single light source means; said pair of photodetector means respectively producing electrical signals corresponding to light falling on said pair of photodetector means from said single light source means; the amount of light falling upon said pair of photodetector means being affected by a flying position of said ink drops in said detecting region; and a single processing means for detecting a horizontal position of an ink drop on the basis of a difference in said electrical signals between said pair of photodetector means, and for detecting a vertical position of the same ink drop on the basis of the sum of said respective electrical signals of said pair of photodetector means.
Claim 3
Dependent Claim
24 words
The system according to claim 1 wherein said pair of photodetector means comprises two photodetectors for generating first and second output voltage signals, respectively.
Claim 4
Dependent Claim
30 words
The system according to claim 2 wherein said signal processing means comprises first means for producing a difference signal representing the difference between said first and second output voltage signals.
Claim 5
Dependent Claim
16 words
The system according to claim 3 wherein said first means for producing comprises a differential amplifier.
Claim 6
Dependent Claim
59 words
The system according to claim 3 wherein said signal processing means further comprises: bias voltage generation circuit for producing a bias voltage; second means for producing a sum signal representing the sum of said first and second output voltage signals; and third means for producing a difference signal representing the difference between said sum signal and said bias voltage.
Claim 7
Dependent Claim
16 words
The system according to claim 5 wherein said third means for producing comprises a differential amplifier.
Claim 8
Dependent Claim
19 words
The system according to claim 5 further comprising a signal processing circuit for controlling said bias voltage generation circuit.
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) | 1991-06-28 | 1991-12-28 | 1992-06-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-06-28 | 1995-12-28 | 1996-06-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-06-28 | 1999-12-28 | 2000-06-28 | $7700.00 | Window Closed / Lapsed |