US3736056A - Apparatus for imparting intermittent rotation to a first member in rotating registry with a second member - Google Patents

Apparatus for imparting intermittent rotation to a first member in rotating registry with a second member Download PDF

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Publication number
US3736056A
US3736056A US00221310A US3736056DA US3736056A US 3736056 A US3736056 A US 3736056A US 00221310 A US00221310 A US 00221310A US 3736056D A US3736056D A US 3736056DA US 3736056 A US3736056 A US 3736056A
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United States
Prior art keywords
shaft
mirror
rotation
clutch
scan
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Expired - Lifetime
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US00221310A
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English (en)
Inventor
R C Burnet
W F Slack
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
DYK RESEARCH CORP VAN
VAN DYK RESEARCH CORP US
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DYK RESEARCH CORP VAN
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Application filed by DYK RESEARCH CORP VAN filed Critical DYK RESEARCH CORP VAN
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Expired - Lifetime legal-status Critical Current

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    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G15/00—Apparatus for electrographic processes using a charge pattern
    • G03G15/22—Apparatus for electrographic processes using a charge pattern involving the combination of more than one step according to groups G03G13/02 - G03G13/20
    • G03G15/28—Apparatus for electrographic processes using a charge pattern involving the combination of more than one step according to groups G03G13/02 - G03G13/20 in which projection is obtained by line scanning
    • G03G15/30—Apparatus for electrographic processes using a charge pattern involving the combination of more than one step according to groups G03G13/02 - G03G13/20 in which projection is obtained by line scanning in which projection is formed on a drum

Definitions

  • ABSTRACT An office copier in which a rotating photoconductive drum is exposed by an intermittently rotating scan mirror.
  • a slip-free clutch intermittently couples the scan mirror to a shaft which rotates in synchronism with the photoconductive drum.
  • the clutch When the clutch is engaged, the scan mirror is caused to rotate in a given direction in precise synchronism with rotation of the photoconductive drum, thus insuring that there issubstantially no scan slip in the resulting latent image formed on the drum surface.
  • the clutch is disengaged and a spring rapidly returns the scan mirror to an initial rest position in preparation for the next scan. Since the amount of rotation of the scan mirror may be varied by varying the time of engagement of the slip-free clutch, this arrangement is especially suitable for office copiers requiring variable scan length capability.
  • the terms rotating registry and registered rotation are utilized to define a relationship between two rotatable members connected through a selectively engagable coupling means whereby, from the instant of engagement to the instant of disengagement of the coupling means, the two rotatable members are rotating at a predetermined angular velocity ratio.
  • the difficult time for maintaining registry between an intermittently rotating member and a constantly rotating member occurs at the commencement of the rotation of the intermittently rotating member. This occurs because at this stage in the operational cycle the inertia of the intermittently rotating member must be overcome.
  • one approach to overcoming the inertia of the scanning device is to provide an early start for the scan mirror. This method of insuring registry is inefficient, however, because the time taken in starting the scan cycle early represents a wastage of machine time and an operating loss.
  • cam/follower devices are limited to a fixed length of possible scan.
  • the scan length of the machine is fixed, e.g., such as to handle paper having a dimension in the direction of scan of 8% inches, and any change in scan length can be accomplished only by'a change in the cam.
  • a second commercial disadvantage of prior art machines is that their operation involves an inherent wastage of machine time. Specifically, in most prior art apparatus, the cams are continuously rotating. Because the cam configuration defines the points in the drum rotation when a cycle may be initiated, any attempt to initiate a cycle other than at these predetermined points will result in a time delay until the cam cycle initiation point is reached.
  • a further object of the present invention is to provide an apparatus for imparting intermittent rotation to a first member in rotating registry with a second member wherein no cam and cam follower structures are utilized to generate the scanning motion.
  • a still further object of the invention is to provide an apparatus for imparting intermittent rotation to a first member in rotating registry with a second member wherein the intermittent rotation of the first member may be initiated at any point of angular rotation of the second member.
  • the apparatus of the present invention may include a first member mounted for rotation, a second member mounted for rotation, coupling means for selectively coupling the first member and the second member for intermittent registered rotation, and motive means for imparting rotation to the first and second members.
  • FIG. 1 is a schematic view of an electrostatic copying system with respect to which the present invention may be utilized;
  • FIG. 2 is a partial perspective view of apparatus according to the invention of the type which is utilized in the electrostatic copying apparatus of FIG. 1;
  • FIG. 3 is a side view, partially in cross-section through the plane 33 of FIG. 2.
  • FIG. 1 an electrostatic copying system designated generally by the reference numeral 10, in which system is incorporated an apparatus for imparting intermittent rotation to a first member in rotating registry with a second member according to the invention.
  • a curved support plate 12 is provided for supporting a document (not shown) bearing an image to be copied.
  • the image to be copied is illuminated by a suitable light source (not shown) and scanned by a rotatably mounted reflecting means viz. mirror 14, which reflects the light from the document to be copied through a suitable lens 15 and thereafter against a fixed reflecting means viz. mirror 16 from which the light is reflected to a photoconductive drum 18 to lay down 'a suitable image on the drum surface.
  • the effect of the image on the surface of the photoconductive drum 18 may be best understood from a consideration of the electrostatic copying process which is utilized with respect to the apparatus 10 of FIG. 1 and typical of those generally known in the art.
  • a discharged surface of photoconductive drum 18, the material of which may be any of those known in the art, e.g., selenium or zinc oxide, is passed under a corona emitter 20 which establishes on the surface of the photoconductive drum a uniform electrostatic charge density.
  • the charged surface of the photoconductive drum 18 is passed under a slit 21 through which the image scanned from the document positioned on document support plate 12 is projected. Exposure of the electrostatically charged photoconductive drum surface to the image results in an electrostatic field image on the drum surface.
  • the now exposed drum surface is subjected to a cascade of developer in developer tank 22 thereby permitting electrostatically charged areas on the drum surface, which correspond to the image to be reproduced, to be coated with the toner from the bath.
  • the photoconductive drum continues to rotate so as to position the developed drum image in proximity with a moving paper 24.
  • the paper is passed in registry with the drum over an image transfer corona emitter 25 to induce the transfer of toner from the drum to paper 24.
  • the paper then is separated from the drum and passed under a heater (fuser) 27 to melt the toner and set the image on the paper.
  • the drum surface is exposed to a further corona emitting device 29 to neutralize any residual charge thereon.
  • a mechanical brushing apparatus 30 is utilized to mechanically remove any excess toner from the surface of the drum.
  • the drum is exposed to a light source 32 to insure adequate discharge of the activated surface of the drum. Thereafter, the drum surface is recharged at the beginning of the next cycle by being passed under corona emitter 20.
  • the present invention relates to that portion of the apparatus 10 which functions to scan the document to be copied and present the scanned image of the document to be copied to the photoconductive drum such that the rate of scan and the rate of rotation of the photoconductive drum are in registry thereby avoiding scan skid as discussed above.
  • an apparatus for imparting intermittent rotation to a first member in rotating registry with .a second member, e.g., the scan portions and the transfer drum of apparatus 10 of FIG. 1, according to the invention is shown perspectively and designated by the general reference numeral 40.
  • apparatus 40 will be described as being a portion of the electrostatic copying apparatus disclosed in FIG. 1 and corresponding elements will be designated by corresponding reference numerals where appropriate.
  • apparatus 40 can be seen to comprise a scan mirror 14 which is mounted for rotation on a longitudinally axially extending shaft 42.
  • scan mirror 14 is mounted in a cradle 43 such that the longitudinal axis of rotation of shaft 42 lieslongitudinally centrally along its upper or reflecting surface.
  • Mirror 14 is a front or first surface mirror, the embodiment shown being a first surface mirror with a reflective coating of sufficient flatness as to not distort the image, such mirrors being generally available.
  • clutch 45 Spaced longitudinally along shaft 42 from the position of mirror 14 is a clutch 45 which, when engaged, transmits rotational movement along shaft 42 to mirror 14 from a belt driven sheave 48.
  • clutch 45 is a fast pick-up, short slip-time, no engagement-slip clutch with a low inertia driven member, the clutch being engageable at any position in the rotation of the driving member.
  • Sheave 48 is rigidly secured to shaft 42, e.g., by a taper lock bushing 49.
  • the surface of sheave 48 is a machined cylindrical surfacesubstantially without runout.
  • shaft 42 is mounted for precise rotation about its longitudinal axis by a plurality of ball bearing assemblies 51 which are supported by suitable pedestals 52. It should be noted, however, that any low friction no-play mounting means may be utilized torotatably support shaft 42.
  • photoconductive drum 18 can be seen to be supported by a longitudinally axially extending shaft 60 which is parallel to shaft 42 and which is rotatably mounted through bearing 62.
  • first sheave 64 is adapted to receive belt 65 therearound which belt also passes around the sheave 48 on shaft 42.
  • Second sheave 68 is adapted to receive a drive belt 69 therearound, which drive belt is driven by a sheave 70 mounted on the output shaft of a motive means 71.
  • motive means 71 can be any of many types known to those skilled in the art, e. g. an electric motor.
  • First sheave 64 in a similar manner to sheave 48, is also provided with a machined cylindrical surface substantially without run-out so as to define a proper surface for receiving belt 65.
  • belt 65 is a metal belt of rectangular cross-section.
  • the material for belt 65 may be stainless steel, beryllium copper or other material having a high Youngs modulus of elasticity.
  • the drive system between the photoconductive drum 18 and scan mirror 14 need not necessarily utilize cylindrical sheaves and a belt having a rectangular cross-section. Rather, other forms of drive may be utilized, e. g. a timing belt drive, so long as a high-friction, non-slip surface-to-surface contact is maintained so as to permit registered rotation between photoconductive drum l8 and scan mirror 14.
  • lever arm 72 Disposed on shaft 42 between central bearing 51 and clutch 45 is a lever arm 72 which is angularly displaceable with shaft 42.
  • Spring 74 Secured to the angularly displaceable end of lever arm 72 is a spring 74 which is secured to a rigid support member 75.
  • Spring 74 is a tension spring for establishing a torque which opposes the rotation of shaft 42 during the engagement of clutch 45.
  • shaft 42 is rotated clockwise as shown in F IG. 2 thereby elongating and loading spring 74.
  • spring 74 acting through lever arm 72 rotates shaft 42 and therewith mirror 14 counter-clockwise until lever arm 72 comes in contact with a stop means 77 which is positioned to limit the counter-clockwise rotation of shaft 42.
  • the positioning of stop means 77 is such as to define the initial position of shaft 42 for any scan cycle.
  • motor 71 may be energized to cause rotation of this output shaft and therewith sheave 70.
  • the rotation of sheave 70 causes displacement of belt 69 and therewith the rotation of sheave 68 which in turn causes rotation of shaft 60 and photoconductive drum 18.
  • the rotation of shaft 60 causes rotation of sheave 64, which rotation is transmitted to sheave 48 on shaft 42 through belt 65.
  • Rotation of sheave 48 causes rotation of that portion of shaft 42 up to the driving side of clutch 45.
  • Clutch 45 can be engaged at any point in the rotation of photoconductive drum 18.
  • a scan cycle can be initiated at any point in machine time and the cycle will commence immediately, without regard for the position of drum 18 or the elements of the connector system between drum 18 and mirror 14.
  • shaft 42 continues to rotate until a signal to disengage the clutch is received whereupon the energy stored in spring 74 acts through lever arm 72 to cause counter rotation of shaft 42 and therewith scan mirror 14 until lever arm 72 comes in contact with the upper surface of stop element 77. At this point the system is ready for a next scan cycle.
  • a principal feature of this invention is to provide an apparatus wherein rotating registry between a constantly rotating member, viz. photoconductive drum 18 in the disclosed embodiment, and an intermittently rotating member viz. scan mirror 14 in the disclosed embodiment, is achieved with consistency.
  • the unique structural coupling arrangement disclo'sed above for achieving this result includes sheave 64 which is rigidly secured to shaft and which drives belt 65 whereby sheave 48 is driven.
  • the sheave-belt surface relationship is such as to establish a sufficient frictional engagement between the belt and sheave to preclude slippage at these points during either the engagement or the engaged drive of clutch 45.
  • various means may be utilized to tension belt 65 if desired.
  • a tensioning sheave (not shown) may be utilized to bear against the surface of belt 65 thereby increasing the frictional engagement between the belt and sheaves 64 and 48 to insure no-slip relationship -for the particular torques established during engagement and disengagement of clutch 45.
  • clutch 45 must be chosen such as to preclude any effective slippage while engaged and during engagement whereby to obviate the possibility of scan skid as discussed above.
  • an electromagnetic disc clutch having the following characteristics is satisfactory for carrying office copier loads wherein the driven member inertia is in the range of .267 lb. inches Acceptable specifications for a satisfactory clutch for such loads are as follows:
  • a clutch for use in the present invention must be capable of being engaged at any point in the rotation of the driving member.
  • the relationship between the belt drive system and the clutch is such as to preclude effective slippage between scan mirror 14 and photoconductive drum 18.
  • the engagement and disengagement of clutch 45 requires that a certain amount of inertia be overcome and, as will be recognized by those skilled in this art, the compensation for such inertia is often a cause of slippage.
  • the structure of the present invention provides that the increased inertia resulting from such an engagement of clutch 45 will not disturb the rotating registry between photoconductive drum 18 and scan mirror 14 but rather will be reflected only in a change in speed of rotation of motor 71.
  • the structure of the present invention permits generation of the scanning motion without the utilization of reciprocating mechanical devices such as cams and cam followers, and the maintenance of a rotating registry between the constantly rotating member and the intermittently rotating member. Accordingly, this structural approach to the problem presents a significant step forward in these arts.
  • Scanning apparatus for forming an image of an object on a surface, comprising:
  • drive means for rotating said drive shaft and moving said surface in mutually synchronous slip-free relationship; an optical element mounted for rotation on a second shaft to scan said object and project an image thereof on said surface when said second shaft is rotated in synchronous relationship with the motion of said surface; means for biasing said second shaft at a given initial angular orientation with respect to said object;
  • said belt drive includes a third shaft uponwhich said drum is rotatably mounted, a first sheave secured to the drive shaft, a second sheave secured to said third shaft, and a belt engaging said sheaves.
  • sheaves include generally cylindrical belt engaging surfaces, said belt being flat and in operative engagement with said belt engaging surfaces.
  • a scan system for a copying apparatus comprising:
  • first mounting means for mounting said first mirror for rotation about a first longitudinal axis; photoconductive drum means;
  • second mounting means for mounting said photoconductive drum means for rotation about a second longitudinal axis, said second longitudinal axis being spaced from and parallel to said first longitudinal axis;
  • coupling means for selectively coupling said first mirror and said photoconductive drum means for registered rotation, said coupling means including a clutch means;
  • a scan system including:
  • longitudinally extending first shaft means secured to said first mirror, said longitudinally extending first shaft means being coaxially with the first longitudinal axis; longitudinally extending second shaft means secured to said photoconductive drum means, said longitudinally extending second shaft means being coaxial with said second longitudinal axis; and wherein said clutch means is in operable engagement with said first shaft means.
  • a scan system according to claim 9, wherein said first mounting means comprises first bearing means for rotatably supporting said first shaft means.
  • a scan system wherein said belt drive includes a first sheave operably secured to said first mirror, a second sheave operably secured to said photoconductive drum, and belt means engaging said first and second sheave means for imparting said registered rotation therebetween.
  • said coupling means includes a belt drive for rotatably connecting said first shaft means and said second shaft means.
  • a scan system wherein said belt drive includes a first sheave secured to said first shaft means, a second sheave secured to said second shaft means, and belt means engaging said first and second sheave means for imparting said registered rotation therebetween.
  • said means for rotating said first mirror in a second angular direction comprises a spring operably secured to said first shaft means, said spring being displaced and subject to load in response to rotation of said first mirror gaged positions without regard to the angular position in said first angular direction. of said first shaft means whereby to permit selective ro- 20.
  • said clutch is operable between engaged and disen-

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Exposure Or Original Feeding In Electrophotography (AREA)
  • Discharging, Photosensitive Material Shape In Electrophotography (AREA)
  • Electrophotography Configuration And Component (AREA)
  • Optical Systems Of Projection Type Copiers (AREA)
  • Facsimile Scanning Arrangements (AREA)
US00221310A 1972-01-27 1972-01-27 Apparatus for imparting intermittent rotation to a first member in rotating registry with a second member Expired - Lifetime US3736056A (en)

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US22131072A 1972-01-27 1972-01-27

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US (1) US3736056A (ja)
JP (1) JPS4884639A (ja)
CA (1) CA977025A (ja)
DE (1) DE2302986A1 (ja)
GB (1) GB1401359A (ja)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4023897A (en) * 1976-01-28 1977-05-17 International Business Machines Corporation Optics drive mechanism
US4135806A (en) * 1974-11-25 1979-01-23 Konishiroku Photo Industry Co., Ltd. Power transmission control mechanism for use in the copying apparatus
US4161359A (en) * 1976-12-17 1979-07-17 Xerox Corporation Apparatus for synchronizing movement between an optical scanning system and an imaging member
US5214472A (en) * 1992-01-03 1993-05-25 Eastman Kodak Company Metal belt drive for recording element in a copier/printer
US20070089557A1 (en) * 2004-09-30 2007-04-26 Solomon Todd R Multi-ply strap drive trains for robotic arms
US20080021440A1 (en) * 2004-09-30 2008-01-24 Solomon Todd R Electro-mechancial strap stack in robotic arms
US10449011B2 (en) 2004-09-30 2019-10-22 Intuitive Surgical Operations, Inc. Offset remote center manipulator for robotic surgery

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5160532A (en) * 1974-11-25 1976-05-26 Konishiroku Photo Ind 1 doryokugenoryoshitefukusuno buzaioanteikudoseshimeuruyona doryokudentatsuseigyokikoojusuru fukushaki

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2593088A (en) * 1949-08-23 1952-04-15 Perkin Elmer Corp Panoramic camera
US3630608A (en) * 1968-11-14 1971-12-28 Pitney Bowes Sage Inc High-speed copier

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2593088A (en) * 1949-08-23 1952-04-15 Perkin Elmer Corp Panoramic camera
US3630608A (en) * 1968-11-14 1971-12-28 Pitney Bowes Sage Inc High-speed copier

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4135806A (en) * 1974-11-25 1979-01-23 Konishiroku Photo Industry Co., Ltd. Power transmission control mechanism for use in the copying apparatus
US4023897A (en) * 1976-01-28 1977-05-17 International Business Machines Corporation Optics drive mechanism
US4161359A (en) * 1976-12-17 1979-07-17 Xerox Corporation Apparatus for synchronizing movement between an optical scanning system and an imaging member
US5214472A (en) * 1992-01-03 1993-05-25 Eastman Kodak Company Metal belt drive for recording element in a copier/printer
US20130239392A1 (en) * 2004-09-30 2013-09-19 Intuitive Surgical Operations, Inc. Method for robotic arms with strap drive trains
US20080021440A1 (en) * 2004-09-30 2008-01-24 Solomon Todd R Electro-mechancial strap stack in robotic arms
US20070089557A1 (en) * 2004-09-30 2007-04-26 Solomon Todd R Multi-ply strap drive trains for robotic arms
US9068628B2 (en) 2004-09-30 2015-06-30 Intuitive Surgical Operations, Inc. Robotic arms with strap drive trains
US9261172B2 (en) 2004-09-30 2016-02-16 Intuitive Surgical Operations, Inc. Multi-ply strap drive trains for surgical robotic arms
US9797484B2 (en) * 2004-09-30 2017-10-24 Intuitive Surgical Operations, Inc. Methods for robotic arms with strap drive trains
US9803727B2 (en) 2004-09-30 2017-10-31 Intuitive Surgical Operations, Inc. Strap guide system and methods thereof for robotic surgical arms
US10449011B2 (en) 2004-09-30 2019-10-22 Intuitive Surgical Operations, Inc. Offset remote center manipulator for robotic surgery
US10595948B2 (en) 2004-09-30 2020-03-24 Intuitive Surgical Operations, Inc. Methods and apparatus for stacked electro-mechancial straps in robotic arms
US10646292B2 (en) * 2004-09-30 2020-05-12 Intuitive Surgical Operations, Inc. Electro-mechanical strap stack in robotic arms
US11160626B2 (en) 2004-09-30 2021-11-02 Intuitive Surgical Operations, Inc. Offset remote center manipulator for robotic surgery

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Publication number Publication date
GB1401359A (en) 1975-07-16
CA977025A (en) 1975-10-28
JPS4884639A (ja) 1973-11-10
DE2302986A1 (de) 1973-08-02

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