# US 4,391,506 A · Driving method and apparatus for illumination type imaging system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 4,391,506 A - Document ID: US4391506A - Status: Granted - Kind: A - Application number: 06/324,309 - Filed: 1981-11-23 - Granted: 1983-07-05 - Earliest claimed: 1980-11-26 - Assignees: Ricoh Company, Ltd. - Inventors: Hiroshi Koide - Web page: https://patentgrep.com/patent/US4391506A ## CPC - G03G 15/305: {with special means to synchronize the scanning optic to the operation of other parts of the machine, e.g. photoreceptor, copy paper} - G03B 27/526: {in which the projection optics move} - G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY - G03B: APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR (optical parts of such apparatus G02B; photosensitive materials or processes for photographic purposes G03C; apparatus for processing exposed photographic materials G03D) ## Abstract A reciprocating illumination type imaging system is driven by a first drive source and a rotatable photoconductive drum is driven by a second drive source. A time period necessary for the drum to rotate a given angle is measured. The measured time period is compared with a predetermined reference time period to thereby estimate a fluctuation component in the time period of rotation of the drum in accordance with a result of the comparison. A start or buildup target speed during a buildup scanning speed motion of the imaging system and a constant target speed during a constant scanning speed motion are individually preset or determined in accordance with the estimated fluctuation component. The imaging system comprises an optical lens having a given focal length. The first and second drive sources constitute a drive mechanism. The preset buildup target speed and/or the preset constant target speed is compensated in conformity with a deviation of the focal length of the lens from a nominal focal length and a deviation of a mechanical precision of the drive mechanism from a nominal mechanical precision. Further, the speed of the imaging system during a constant scanning speed motion is detected. The preset constant target speed is compensated in accordance with the detected speed of the imaging system. ## Claims ### Claim 1 A method of driving a movable imaging system which is driven by a first drive source in synchronism with a movable photoconductive member which is driven by a second drive source, said method comprising the steps of: (a) measuring a time period necessary for the photoconductive member to move a given distance; (b) comparing the measured time period with a predetermined reference time period to thereby estimate a fluctuation component in the time period of movement of the photoconductive member in accordance with a result of the comparison; (c) presetting or determining a buildup target speed and a constant target speed during a buildup scanning speed motion and a constant scanning speed motion of the imaging system in accordance with the estimated fluctuation component respectively; and (d) moving the imaging system at the preset buildup and constant target speeds during buildup and constant scanning speed motions thereof, respectively; whereby the imaging system is moved in synchronism with the photoconductive member. ### Claim 2 (depends on 1) A method as claimed in claim 1, in which the imaging system comprises an optical lens having a given focal length and the first and second drive sources constitute a drive mechanism, said method further comprising the following step (e), after step (c), of: (e) compensating the preset buildup target speed in conformity with a deviation of the focal length of the lens from a nominal focal length and a deviation of a mechanical precision of the drive mechanism from a nominal mechanical precision. ### Claim 3 (depends on 1) A method as claimed in claim 1, in which the imaging system comprises an optical lens having a given focal length and the first and second drive sources constitute a drive mechanism, said method further comprising the following step (f), after step (c), of: (f) compensating the preset constant target speed in conformity with a deviation of the focal length of the lens from a nominal focal length and a deviation of the mechanical precision of the drive mechanism from a nominal mechanical precision. ### Claim 4 (depends on 1) A method as claimed in claim 1, further comprising the following steps (g) and (h), after step (c), of: (g) detecting a speed of the imaging system during a constant scanning speed motion; and (h) compensating the preset constant target speed in accordance with the detected speed of the imaging system. ### Claim 5 (depends on 1) A method as claimed in claim 1, in which said photoconductive member comprises a rotatable drum of an electrostatic copying apparatus on which an electrostatic image of an original document is formed by the imaging system. ### Claim 6 An apparatus for driving a reciprocable imaging system in synchronism with a movable photoconductive member in electrostatic photography comprising: first drive means for driving the imaging system; second drive means for driving the photoconductive member; measuring means for measuring a time period necessary for the photoconductive member to move a given distance; comparing means for comparing the time period with a predetermined reference time period to thereby estimate a fluctuation component in the time period of movement of the photoconductive member in accordance with a result of the comparison; and presetting means for determining a buildup target speed and a constant target speed during a buildup scanning speed motion and a constant scanning speed motion of the imaging system in accordance with the estimated fluctuation component respectively; whereby the imaging system is moved at the preset buildup and constant target speeds during buildup and constant scanning speed motions, respectively, so that the imaging system is moved in synchronism with the photoconductive member. ### Claim 7 (depends on 6) An apparatus as claimed in claim 6, in which the imaging system comprises an optical lens having a given focal length and the first and second drive sources constitute a drive mechanism, said apparatus further comprising first compensating means for compensating the preset buildup target speed in conformity with a deviation of the focal length from a nominal focal length of the lens and a deviation of a mechanical precision of the drive mechanism from a nominal mechanical precision. ### Claim 8 (depends on 7) An apparatus as claimed in claim 7, further comprising second compensating means for compensating the preset constant target speed in conformity with the deviation of the focal length of the lens and the deviation of the mechanical precision of the drive mechanism. ### Claim 9 (depends on 6) An apparatus as claimed in claim 6, further comprising detecting means for detecting a speed of the imaging system during a constant scanning speed motion, and third compensating means for compensating the preset constant target speed in accordance with the detected speed of the imaging system.