US4987426A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Laser irradiating apparatus and laser recording apparatus using the same
Assignee: Canon Inc
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Filing: 1989-09-07
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Granted: 1991-01-22
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Expires: 2009-09-07
Abstract
Abstract The present invention provides a laser irradiating apparatus which comprises a laser which can be directly modulated by a modulation signal, and in which laser oscillation becomes unstable when the intensity of the modulation signal is smaller than a predetermined threshold value, and laser oscillation becomes stable when the intensity of the modulation signal is larger than the predetermined threshold value, means for comparing the intensity of the modulation signal with a predetermined value near the predetermined threshold value, and means for modulating an emission time of the laser when the intensity of the modulation signal is smaller than the predetermined value.
Inventors
- 👤 Shinichi Ota
- 👤 Keiichi Kawasaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 23:38
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/40; H04N1/40025; H04N1/40043; H04N1/40037
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
97 words
A laser irradiating apparatus comprising: a laser which can be directly modulated by a modulation signal, and in which laser oscillation becomes unstable when the intensity of the modulation signal is smaller than a predetermined threshold value, and laser oscillation becomes stable when the intensity of the modulation signal is larger than the predetermined threshold value: means for comparing the intensity of said modulation signal with a predetermined value near said predetermined threshold value; and means for modulating an emission time of said laser when the intensity of said modulation signal is smaller than said predetermined value.
Claim 2
Dependent Claim
97 words
A laser irradiating apparatus comprising: a laser which can be directly modulated by a modulation signal, and in which laser oscillation becomes unstable when the intensity of the modulation signal is smaller than a predetermined threshold value, and laser oscillation becomes stable when the intensity of the modulation signal is larger than the predetermined threshold value: means for comparing the intensity of said modulation signal with a predetermined value near said predetermined threshold value; and means for modulating an emission time of said laser when the intensity of said modulation signal is smaller than said predetermined value.
Claim 3
Dependent Claim
15 words
A laser irradiating apparatus according to claim 1, wherein said laser is a semiconductor laser.
Claim 4
Dependent Claim
25 words
A laser irradiating apparatus according to claim 2, wherein said predetermined threshold value is an inflection point from an LED irradiation to a laser oscillation.
Claim 5
Dependent Claim
107 words
A recording apparatus comprising: a laser which can be directly modulated by a modulation signal, and in which laser oscillation becomes unstable when the intensity of the modulation signal is smaller than a predetermined threshold value, and laser oscillation becomes stable when the intensity of the modulation signal is larger than the predetermined threshold value; means for comparing the intensity of said modulation signal with a predetermined value near said predetermined threshold value; means for modulating an emission time of said laser when the intensity of said modulation signal is smaller than said predetermined value; and means for irradiating said modulated laser light on a recording medium.
Claim 6
Dependent Claim
107 words
A recording apparatus comprising: a laser which can be directly modulated by a modulation signal, and in which laser oscillation becomes unstable when the intensity of the modulation signal is smaller than a predetermined threshold value, and laser oscillation becomes stable when the intensity of the modulation signal is larger than the predetermined threshold value; means for comparing the intensity of said modulation signal with a predetermined value near said predetermined threshold value; means for modulating an emission time of said laser when the intensity of said modulation signal is smaller than said predetermined value; and means for irradiating said modulated laser light on a recording medium.
Claim 7
Dependent Claim
31 words
A laser recording apparatus according to claim 4, wherein said recording medium is a recording sheet, and recording is two-dimensionally performed by relatively moving the laser light and the recording sheet.
Claim 8
Dependent Claim
17 words
A laser recording apparatus according to claim 5, wherein said recording medium is a photosensitive silver-salt film.
Claim 9
Dependent Claim
119 words
A laser irradiating apparatus comprising: a laser which can be directly modulated by a modulation signal, and in which laser oscillation becomes unstable when the intensity of the modulation signal is smaller than a predetermined threshold value, and laser oscillation becomes stable when the intensity of the modulation signal is larger than the predetermined threshold value; means for comparing the intensity of said modulation signal with a predetermined value near said predetermined threshold value; means for modulating an emission intensity of said laser when the intensity of said modulation signal is larger than said predetermined value; and means for modulating an emission time of said laser when the intensity of said modulation signal is smaller than said predetermined value.
Claim 10
Dependent Claim
119 words
A laser irradiating apparatus comprising: a laser which can be directly modulated by a modulation signal, and in which laser oscillation becomes unstable when the intensity of the modulation signal is smaller than a predetermined threshold value, and laser oscillation becomes stable when the intensity of the modulation signal is larger than the predetermined threshold value; means for comparing the intensity of said modulation signal with a predetermined value near said predetermined threshold value; means for modulating an emission intensity of said laser when the intensity of said modulation signal is larger than said predetermined value; and means for modulating an emission time of said laser when the intensity of said modulation signal is smaller than said predetermined value.
Claim 11
Dependent Claim
35 words
A laser irradiating apparatus according to claim 7, wherein a nonlinear characteristic of a composite of the laser and a recording medium is corrected into a substantially linear characteristic by referring to a look-up table.
Claim 12
Dependent Claim
112 words
A laser irradiating apparatus comprising: a laser which can be directly modulated by a modulation signal, and in which laser oscillation becomes unstable when the intensity of the modulation signal is smaller than a predetermined threshold value, and laser oscillation becomes stable when the intensity of the modulation signal is larger than the predetermined threshold value; means for comparing the intensity of said modulation signal with a predetermined value near said predetermined threshold value; and means for modulating an emission time of said laser so that an area exposed by said laser is broadened with respect to both sides one picture element when said recording signal is smaller than said predetermined value.
Claim 13
Dependent Claim
112 words
A laser irradiating apparatus comprising: a laser which can be directly modulated by a modulation signal, and in which laser oscillation becomes unstable when the intensity of the modulation signal is smaller than a predetermined threshold value, and laser oscillation becomes stable when the intensity of the modulation signal is larger than the predetermined threshold value; means for comparing the intensity of said modulation signal with a predetermined value near said predetermined threshold value; and means for modulating an emission time of said laser so that an area exposed by said laser is broadened with respect to both sides one picture element when said recording signal is smaller than said predetermined value.
Claim 14
Dependent Claim
135 words
A laser irradiating apparatus comprising: a laser which can be directly modulated by a modulation signal, and in which laser oscillation becomes unstable when the intensity of the modulation signal is smaller than a predetermined threshold value, and laser oscillation becomes stable when the intensity of the modulation signal is larger than the predetermined threshold value; means for comparing the intensity of said modulation signal with a predetermined value near said predetermined threshold value; means for modulating an emission intensity of said laser when the intensity of said modulation signal is larger than said predetermined value; and means for modulating an emission time of said laser so that an area exposed by said laser is broadened with respect to both sides of one picture element, when said recording signal is smaller than said predetermined value.
Claim 15
Dependent Claim
135 words
A laser irradiating apparatus comprising: a laser which can be directly modulated by a modulation signal, and in which laser oscillation becomes unstable when the intensity of the modulation signal is smaller than a predetermined threshold value, and laser oscillation becomes stable when the intensity of the modulation signal is larger than the predetermined threshold value; means for comparing the intensity of said modulation signal with a predetermined value near said predetermined threshold value; means for modulating an emission intensity of said laser when the intensity of said modulation signal is larger than said predetermined value; and means for modulating an emission time of said laser so that an area exposed by said laser is broadened with respect to both sides of one picture element, when said recording signal is smaller than said predetermined value.
Claim 16
Dependent Claim
36 words
A laser irradiating apparatus according to claim 10, wherein the means for modulating the emission time performs a time modulation by comparing a triangular wave having a period of one picture element with said recording signal.
Claim 17
Dependent Claim
109 words
A laser irradiating apparatus comprising: a laser which can be directly modulated by a modulation signal, and in which laser oscillation becomes unstable when the intensity of the modulation signal is smaller than a predetermined threshold value, and laser oscillation becomes stable when the intensity of the modulation signal is larger than the predetermined threshold value; means for comparing the intensity of said modulation signal with a predetermined value near said predetermined threshold value; and means for modulating an emission time of said laser so that said laser operates plural times within a period corresponding to one picture element when said recording signal is smaller than said predetermined value.
Claim 18
Dependent Claim
109 words
A laser irradiating apparatus comprising: a laser which can be directly modulated by a modulation signal, and in which laser oscillation becomes unstable when the intensity of the modulation signal is smaller than a predetermined threshold value, and laser oscillation becomes stable when the intensity of the modulation signal is larger than the predetermined threshold value; means for comparing the intensity of said modulation signal with a predetermined value near said predetermined threshold value; and means for modulating an emission time of said laser so that said laser operates plural times within a period corresponding to one picture element when said recording signal is smaller than said predetermined value.
Claim 19
Dependent Claim
131 words
A laser irradiating apparatus comprising: a laser which can be directly modulated by a modulation signal, and in which laser oscillation becomes unstable when the intensity of the modulation signal is smaller than a predetermined threshold value, and laser oscillation becomes stable when the intensity of the modulation signal is larger than the predetermined threshold value; means for comparing the intensity of said modulation signal with a predetermined value near said predetermined threshold value; means for modulating an emission intensity of said laser when the intensity of said modulation signal is larger than said predetermined value; and means for modulating an emission time of said laser so that said laser operates plural times within a period corresponding to one picture element when said recording signal is smaller than said predetermined value.
Claim 20
Dependent Claim
131 words
A laser irradiating apparatus comprising: a laser which can be directly modulated by a modulation signal, and in which laser oscillation becomes unstable when the intensity of the modulation signal is smaller than a predetermined threshold value, and laser oscillation becomes stable when the intensity of the modulation signal is larger than the predetermined threshold value; means for comparing the intensity of said modulation signal with a predetermined value near said predetermined threshold value; means for modulating an emission intensity of said laser when the intensity of said modulation signal is larger than said predetermined value; and means for modulating an emission time of said laser so that said laser operates plural times within a period corresponding to one picture element when said recording signal is smaller than said predetermined value.
Claim 21
Dependent Claim
40 words
A laser irradiating apparatus according to claim 13, wherein the means for modulating the emission time performs a time modulation by comparing a triangular wave having a period of an integer multiple of one picture element with said recording signal.
Claim 22
Dependent Claim
150 words
A recording apparatus comprising: a laser which can be directly modulated by a modulation signal, and in which laser oscillation becomes unstable when the intensity of the modulation signal is smaller than a predetermined threshold value, and laser oscillation becomes stable when the intensity of the modulation signal is larger than the predetermined threshold value; means for comparing the intensity of said modulation signal with a predetermined value near said predetermined threshold value; means for modulating an emission intensity of said laser when the intensity of said modulation signal is larger than said predetermined value; means for modulating an emission time of said laser when the intensity of said modulation signal is smaller than said predetermined value; means for performing a main scanning of said modulated laser light on a recording medium; and means for performing a subscanning of said recording medium in a direction crossing with said mean scanning.
Claim 23
Dependent Claim
150 words
A recording apparatus comprising: a laser which can be directly modulated by a modulation signal, and in which laser oscillation becomes unstable when the intensity of the modulation signal is smaller than a predetermined threshold value, and laser oscillation becomes stable when the intensity of the modulation signal is larger than the predetermined threshold value; means for comparing the intensity of said modulation signal with a predetermined value near said predetermined threshold value; means for modulating an emission intensity of said laser when the intensity of said modulation signal is larger than said predetermined value; means for modulating an emission time of said laser when the intensity of said modulation signal is smaller than said predetermined value; means for performing a main scanning of said modulated laser light on a recording medium; and means for performing a subscanning of said recording medium in a direction crossing with said mean scanning.
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) | 1994-01-21 | 1994-07-23 | 1995-01-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-01-21 | 1998-07-23 | 1999-01-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-01-21 | 2002-07-23 | 2003-01-22 | $7700.00 | Window Closed / Lapsed |