EP0147835A2
Expired / Lapsed
EP
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Light beam scanning apparatus
Assignee: Fujifilm Holdings Corp
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Filing: 1984-12-21
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Granted: —
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Expires: 2004-12-21
Abstract
Abstract In a light beam scanning apparatus, two photodetectors are positioned in spaced relation by a predetermined distance within a scanning region in a main scanning direction. The start and the end of scanning in the main scanning direction are directed by the photodetectors. The scanning speed of a main scanning means is controlled so that a predetermined number of pulses of a pulse signa! having a predetermined period are input within the time between the start and the end of scanning in the main scanning direction. Or, a single photodetector is positioned within the scanning region, and the scanning time from the start of scanning to the photodetector is detected by use of the photodetector. The initial position of scanning is controlled so that a predetermined number of pulses of the pulse signal having a predetermined period are input within the scanning time.
Inventors
- 👤 Kazuo C/O Fuji Photo Film Co. Ltd. Horikawa
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 15:31
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/04; H04N1/047; H04N1/053; H04N1/113; H04N1/1135; H04N1/12; H04N2201/00; H04N2201/024; H04N2201/02406; H04N2201/02439; H04N2201/04; H04N2201/047; H04N2201/04701; H04N2201/0471; H04N2201/04732; H04N2201/04744; H04N2201/04753; H04N2201/04755; H04N2201/04794
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
159 words
A light beam scanning apparatus comprising: i) a scanning means for scanning a material, which is to be scanned, by a light beam in accordance with a scanning means control signal, ii) a first photodetector and a second photodetector positioned in spaced relation to each other by a predetermined distance in a scanning direction of said light beam in the vicinity of said material, said first photodetector and said second photodetector detecting said light beam and generating a first pulse and a second pulse respectively, and iii) a means for receiving said first pulse generated by said first photodetector and said second pulse generated by said second photodetector and calculating the time between said first pulse and said second pulse, and iv) a control means for adjusting said scanning means control signal on the basis of the calculated time, thereby controlling the scanning speed of said light beam so that the detected speed becomes equal to a predetermined speed.
Claim 2
Dependent Claim
159 words
A light beam scanning apparatus comprising: i) a scanning means for scanning a material, which is to be scanned, by a light beam in accordance with a scanning means control signal, ii) a first photodetector and a second photodetector positioned in spaced relation to each other by a predetermined distance in a scanning direction of said light beam in the vicinity of said material, said first photodetector and said second photodetector detecting said light beam and generating a first pulse and a second pulse respectively, and iii) a means for receiving said first pulse generated by said first photodetector and said second pulse generated by said second photodetector and calculating the time between said first pulse and said second pulse, and iv) a control means for adjusting said scanning means control signal on the basis of the calculated time, thereby controlling the scanning speed of said light beam so that the detected speed becomes equal to a predetermined speed.
Claim 3
Dependent Claim
65 words
An apparatus as defined in Claim 1 wherein said means for calculating the time between said first pulse and said second pulse is provided with a counter for receiving pulses from an oscillator which generates pulses of a predetermined period, receiving said first pulse and said second pulse and counting said pulses of predetermined period which are input-between said first pulse and said second pulse.
Claim 4
Dependent Claim
49 words
An apparatus as defined in Claim 2 wherein said control means comprises a comparison circuit for comparing the output of said counter with a predetermined value, and a means for adjusting the gradient of said scanning means control signal on the basis of the output of said comparison circuit.
Claim 5
Dependent Claim
42 words
An apparatus as defined in Claim 3 wherein said means for adjusting the gradient of said scanning means control signal, adjusts the gradient of said scanning means control signal so that the difference between said count and said predetermined value is minimized.
Claim 6
Dependent Claim
141 words
A light beam scanning apparatus comprising: i) a scanning means for scanning a material, which is to be scanned, by a light beam in accordance with a scanning means control signal, ii) a single photodetector positioned within a scanning region of said light beam for detecting said light beam and generating a pulse, iii) a start point detecting means for detecting the start-point-of each scanning by said scanning means and generating a signal corresponding to said start point, iv) a means for receiving said signal corresponding to said start point and the output pulse of said photodetector and calculating the time between said signal and said pulse, and v) a control means for adjusting the initial level of said scanning means control signal on the basis of the calculated time and controlling the start point of scanning by said light beam.
Claim 7
Dependent Claim
141 words
A light beam scanning apparatus comprising: i) a scanning means for scanning a material, which is to be scanned, by a light beam in accordance with a scanning means control signal, ii) a single photodetector positioned within a scanning region of said light beam for detecting said light beam and generating a pulse, iii) a start point detecting means for detecting the start-point-of each scanning by said scanning means and generating a signal corresponding to said start point, iv) a means for receiving said signal corresponding to said start point and the output pulse of said photodetector and calculating the time between said signal and said pulse, and v) a control means for adjusting the initial level of said scanning means control signal on the basis of the calculated time and controlling the start point of scanning by said light beam.
Claim 8
Dependent Claim
81 words
An apparatus as defined in Claim 5 wherein said means for calculating the time between said signal corresponding to said start point and said output pulse of said photodetector is provided with a counter for receiving pulses from an oscillator which generates the pulses of a predetermined period, receiving said signal corresponding to said start point and said output pulse of said photodetector, and counting said pulses of the predetermined period which are input between said signal and said output pulse.
Claim 9
Dependent Claim
50 words
An apparatus as defined in Claim 6 wherein said control means comprises a comparison circuit for comparing the output of said counter with a predetermined value, and a means for adjusting the initial level of said scanning means control signal on the basis of the output of said comparison circuit.
Claim 10
Dependent Claim
35 words
An apparatus as defined in Claim 7 wherein said means for adjusting said initial level adjusts said initial level so that the difference between the output of said counter and the predetermined count is minimized.
References Cited (Backward Citations)
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