US4791591A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for correcting scanning rate deviation of a galvanometer and correcting method thereof
Assignee: Fujifilm Holdings Corp
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Filing: 1985-11-13
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Granted: 1988-12-13
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Expires: 2005-11-13
Abstract
Abstract A method and apparatus for correcting deviation from a constant scanning speed of a galvanometer driven by a linear drive signal, characterized in that the linear drive signal for driving the galvanometer is converted into a non-linear drive signal in accordance with predetermined correction data to thereby reduce the deviation to zero.
Inventors
- 👤 Katsumi Asanuma
- 👤 Hidetoshi Shinada
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 00:36
CPC Classifications
G; G06; G06K; G06K15/00; G06K15/02; G06K15/12; G06K15/1204; G06K15/1219; G01; G01D; G01D3/00; G01D3/02; G01D3/022; G06K15/1295
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
107 words
An apparatus for correcting deviation from a constant scanning speed of a galvanometer driven by a linear drive signal, comprising: memory means for storing correction data for zeroing the deviation from a constant scanning speed, means for reading out the correction data in response to an input address signal; first digital-to-analog converting means for converting the correction data into an analog correction signal; second digital-to-analog converting means for converting the input address signal into the linear drive signal; and adder means for summing the linear drive signal and the analog correction signal to derive a non-linear drive signal for the galvanometer which reduces the deviation to zero.
Claim 2
Independent Claim
107 words
An apparatus for correcting deviation from a constant scanning speed of a galvanometer driven by a linear drive signal, comprising: memory means for storing correction data for zeroing the deviation from a constant scanning speed, means for reading out the correction data in response to an input address signal; first digital-to-analog converting means for converting the correction data into an analog correction signal; second digital-to-analog converting means for converting the input address signal into the linear drive signal; and adder means for summing the linear drive signal and the analog correction signal to derive a non-linear drive signal for the galvanometer which reduces the deviation to zero.
Claim 3
Dependent Claim
16 words
An apparatus as claimed in claim 1 wherein the memory means is a read only memory.
Claim 4
Dependent Claim
49 words
An apparatus as claimed in claim 1 further comprising; reference data generating means for generating reference data indicative of any difference between the actual scanning speed and the constant scanning speed, and means for updating the correction data stored in the memory means in accordance with the reference data.
Claim 5
Dependent Claim
16 words
An apparatus as claimed in claim 3 wherein the memory means is a random access memory.
Claim 6
Dependent Claim
14 words
An apparatus as claimed in claim 3 wherein the memory means is an EPROM.
Claim 7
Independent Claim
163 words
An apparatus for correcting deviation from a constant scanning speed of a galvanometer driven by a linear drive signal, comprising: memory means for storing correction data for a linear drive signal; means for reading out the stored correction data in response to an input address signal; digital-to-analog converting means for converting the correction data into an analog non-linear drive signal which reduces the speed deviation to zero; reference data generating means for generating reference data indicative of any differences between an actual scanning speed of the galvanometer and the constant scanning speed; and means for updating the correction data stored in the memory means in accordance with the reference data; wherein the reference data generating means includes an optical mark signal generator, an optical mark signal counter responsive to the output of said optical mark signal generator, a reference value setter for setting a reference value and a comparator for comparing the output of said optical mark signal counter with said reference value.
Claim 8
Independent Claim
163 words
An apparatus for correcting deviation from a constant scanning speed of a galvanometer driven by a linear drive signal, comprising: memory means for storing correction data for a linear drive signal; means for reading out the stored correction data in response to an input address signal; digital-to-analog converting means for converting the correction data into an analog non-linear drive signal which reduces the speed deviation to zero; reference data generating means for generating reference data indicative of any differences between an actual scanning speed of the galvanometer and the constant scanning speed; and means for updating the correction data stored in the memory means in accordance with the reference data; wherein the reference data generating means includes an optical mark signal generator, an optical mark signal counter responsive to the output of said optical mark signal generator, a reference value setter for setting a reference value and a comparator for comparing the output of said optical mark signal counter with said reference value.
Claim 9
Independent Claim
112 words
An apparatus for correcting deviation from a constant scanning speed of a galvanometer driven by a linear drive signal, comprising: random access memory means for storing correction data for a linear drive signal; means for reading out the stored correction data in response to an input address signal; digital-to-analog converting means for converting the correction data into an analog non-linear drive signal which reduces the speed deviation to zero; reference data generating means for generating reference data indicative of any difference between an actual scanning speed of the galvanometer and the constant scanning speed,; and means for updating the correction data stored in the memory means in accordance with the reference data.
Claim 10
Independent Claim
112 words
An apparatus for correcting deviation from a constant scanning speed of a galvanometer driven by a linear drive signal, comprising: random access memory means for storing correction data for a linear drive signal; means for reading out the stored correction data in response to an input address signal; digital-to-analog converting means for converting the correction data into an analog non-linear drive signal which reduces the speed deviation to zero; reference data generating means for generating reference data indicative of any difference between an actual scanning speed of the galvanometer and the constant scanning speed,; and means for updating the correction data stored in the memory means in accordance with the reference data.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-12-13 | 1992-06-13 | 1992-12-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-12-13 | 1996-06-13 | 1996-12-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-12-13 | 2000-06-13 | 2000-12-13 | $7700.00 | Window Closed / Lapsed |