Note: Descriptions are shown in the official language in which they were submitted.
9~
BA~CKGROUND OF THE IN~,IENTION
This invention ~reIates to a drive system for a multimode
reproducing apparatus preferably of the electrostatographic type.
rhe drive system includes means for selectively driving sub-
systems of the apparatus at a plurality of speeds.
A variety of eIectrostatographic reproducing machines are
commercially employed which have different modes of operation.
One type of machine utilizes a movlng original exposure system
wherein an original document is moved past a fixed slit optical
la system for projecting an image onto a moving photoconductive ~¦
surface. These machines include a means for changing the mag-
nification of the projected image and the speed of the moving
original to pro~7ide reduction copiesO Exemplary of patents in
this area is U. S. Patent No . 3,076,392 to Cerasani et al.
Other machines have been adapated to copy stationary
original documents at a variety of magnifications or reductions
through the use of a scanning optical system with differen-t
scanning speeds. Exemplary of patents in thls area are U. S. ~ '
Patent Nos. 3,476,478 to Rees, Jr.; 3,542,467 to Fergeson;
U. S. Patent No. 3,614,222 to Post; and 3,837,743 to Amemiya.
The aforenoted machines are adapted to provide one or
more modes of copying having different magnifications. Other
forms of multi-mode copiers are available commercially. For
example, in the Xerox 3100 LDC machine an optical system is
provided which enables the machine to copy from a stationary
original in a first scanning mode or from a moving original in
a second fixed optical mode. This latter mode is particularly
adapted for copying documents larger than the
~'' '. .
~; - 2 -
39l~
conventional viewing platen size. U. S. Patent No. 3,877,804
to Hoppner is illustrative of a machine similar in many respects
to the 3100 LDC machine.
Reproducing apparatuses including the capability of
making copies from both moving and stationary originals are
also described in UO S. Patent No. 3,833,296 to Vola, and in
IBM Technical Disclosure Bulletin, Vol. 12, No. 1, at page
173, June 1969.
It has been found desirable, in accordance with the
present invention, to provide a multi-mode reproducing apparatus
having the unique features of the 3100 LDC machine, including
its extremely compact size, but also having the capability o~
re~uction copying. ;
One area of interest in accordance with the present
invention is the speed changing mechanism for changing the
speed at which th saanning optical system is moved past a
fixed optical system. The various~patents alluded to above
have employed a variety of speed changing mechanisms. Yet~
another approach to a variable speed control system for a
variable magnification copying machine is described in
.
Japanese laid open patent pu~lication No. 84239/1973 which was
laid open for public inspection October 13, 1973. The system
described therein comprises a source of drive input to an
epicyclic gearing or causing a revolution of a planet gear,
and a source of drive input or rotating a sun gear, and means
for selectively connecting these sources with the epicyclic
gearing. The epicyclic gearing has an output shaft for driving
a movable reflecting mirror of the scanning optical system.
A vari~ty of patents have issued on variable speed
drive mechanisms. In U. S. Patent Nos. 731,474; 731,472;
1,394,125; and 2,727,602; a variety of apparatuses are shown
wherein a plurality of input gears are arranged about a common
shaft in engagement with corresponding output gears arranged
about an output shaft. One of the gear pairs is selectively
engaged by a suitable mechanism in order to control the speed
of the output shaft.
U. S~ Patent ~o. 2,975,648 to Doerres shows the use
of electrically controllable spring clutches for a power
transmitting device.
U. 5. Patent No. 3,220,275 to Hewes et al. shows the
use of solenoid ~ontrolled spring clutches for a multi-speed
power transmission. Spring loaded pawls acting on clutch
detent collars provide normally disengaged clutches. The
desired clutch is engaged to transmit power by a solenoid which
is actuated to withdraw the pawl from the clutch detent collar.
Another area of interest in accordance with the
present invention involves mechanisms for automatically
returning a multi-mode reproducing machine to a desired base
mode of operation after a copying operation in a different
mode has ended. One approach to such a mechanism is described
in U. S. Patent NoO 3,779,642 to Ogawa et al. In that patent
a device is provided for automatically returning an optical
system to a "usual" magnification position when the main
switch for the copier is turned off.
SI~MMARY O F THE INVENTION
In accordance with this invention a reproducing
apparatus is provided for producing copies of a document.
In accordance with one embodiment, the apparatus
includes a transparent viewing platen and means for advancing
the document over the platen selectively at one of a plurality
of desired speeds. The advancing means is driven by an
apparatus which includes a driven input shaft and an output
shaft. A pair of drive members for imparting a first desired
speed to the output shaft comprise a first member mounted to
the input shaft and a second member coupled to the first member
and mounted to the output shaft by a first normally engaged
ovexrunning clutch. An additional pair of d ive members for
imparting a second desired speed to the output shaft gxeater
than the first speed comprise a third member mounted to the
input shaft and a fourth membex coupled to the thixd member,
and mounted to the output shaft by a second normally engaged
overrunning clutch~ Means associated with the second overrunning
clutch selecti~-ely disengage the fourth member from the output
shaft. Therefore~ in accordance with this invention the speed
o~ the output shaft is controlled by the highest speed imparting
pair of drive members having an engaged clutch.
Preferably, the drive members comprise meshed gears,
and additional pairs of drive members may be provided to
provide addi.tional speeds.
In accordance with another embodiment of this
inventi.on means are provided for viewing the document and for
projecting an image thereof onto a photosensitive surface
arranged for movement at a desired speed. A means provides
23~38
relative movement between the document and the viewing
means selectively at one of a plurality of desired speeds,
and a means associated with the viewing mear,s provides
select.ively one of a plurality of desired projected image
magnifications. A drive means for driving the relative
movement providing means is essentially the same as that set
forth for the previously described embodiment.
In accordance with yet another embodiment of the
reproducing apparatus of this invention, an automatic
conditioning means is provided for automatically conditioning
the previously described relative movement providing means to
provide a base mode speed after it has finished operation at
a speed different from the base mode speed, Means preferably
are also provided for automatically conditioning the projected
image magnification providing means to provlde a base mode
magnification after it has finished operation at a magnifi-
cation different from the base mode magnification~
The drive system in accordance with this invention
represents an extremely compact apparatus wherein the various
output speeds may be provided by a simple mechanically
actuated mechanism.
Accordingly, it is an object of the present invention
to provide a reproducing apparatus for producing copies of
a document including a drive means for providing selectively
one of a plurality o desired speeds.
It is a further object of this invention to provide
an apparatus as above for providing copies of a document
selectively at one of a plurality of magnifications.
It is a still further object of this invention to
provide an apparatus as above which may be conditioned auto-
matically to provide a base speed after it has finished
operation at a speed different from the base speed.
These and other objects will become more apparent
from the following description and drawing~ in which:
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a schematic view of a reproducing apparatus
in accordance with one embodiment of tha present invention.
Figure 2 is a partial top view of the apparatus of
Figure 1 showirg the document feeder with the cover removed.
Figure 3 is a partial perspective view of the document
feeder drive system in accordance with one embodiment of~this
invention.
Figures 4A and 4B comprise partial side views
illustratîng the operation of the drive selection mechanism.
Figure 5 is a perspective view of an alternative
embodiment of a drive mechanism in accordance with this
invention.
Figure 6 is a top view of a lens and mirror trans-
lation apparatus in accordance with one embodiment of this
invention.
Figure 7 is a side view partially cut away of the
lens and mirror translation apparatus of Figure 6.
Figure 8 is a front view of a lens carriage in
accordance with one embodiment of this invention.
Figures 9A and 9B comprise partial side views
illustrating the operation of an alternative drive selection
mechanism~
-- 7 --
~ 23~8
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the background of this invention there has been
set out a number of patents dealing with reproducing apparatuses
adapted to function in one or more modes of operation. Some
of these apparatuses are capable of imaging from a moving or
a stationary document and some of the apparatuses are capable
of making copies in a variety of selected magnifications --
including reduced magnifications.
When one attempts to combine these modes of operation
into a single reproducing apparatus of a fairly compact nature
significant problems arise because of the necessity of operating
various of the systems in the apparatus selectively at one of
a plurality of different speeds.
In accordance with the present invention a multi-
mode reproducing apparatus is provided~which can be extremely
compact and which includes a drive system for selectively
driving sub-systems of the machine at one of a plurality of
desired speeds. Various embodiments may be provided in
accordance with the present invention. The drive system could
be utili~ed to drive a document feeding apparatus for moving
oriyinal exposure or to provide relative movement between a
document and an exposure system, e.g., it could be employed
for driving a scanning optical system. The apparatus which
will be described preferably features a unique automatic
conditioning system which resets the drive system to a base
output speed after it has finished operation at a speed other
than the base speed.
In accordance with one embodiment o~ the present
invention the apparatus includes a transparent viewing platen
and means for advancing the document over the platen selectively
at one of a plurality of desired speeds. The advancing means
is driven by an apparatus which includes ~ driven input shaft
and an output shaft. A pair o drive members for imparting a
first desired speed to the output shaft comprises a first
memher mounted to the input shaft and a second member coupled
to the first member and mounted to the output shaft by a first
normally engaged overrunning clutch. An additional pair of
drive members for imparting a second desired speed to the
output shaft, greater than the ~irst speed, comprise a third
member mounted to the input shaft and a fourth member coupled
to the third member and mounted to the output shaft by a
second normally engaged overrunning clutch. Means associated
with the second overrunning clutch selectively disengage
tha fourth member from the output shaft.
Preferably, the drive members comprise meshed gears
and additional pairs of drive members may be provided to
provide additional selective speeds.
Therefore, in accordance with this invention the
speed of the output shaft is controlled by the highest speed
imparting pair of drive members having an engaged clutch.
Any engaged clutches associated with a lower speed imparting
pair of drive members are overrun.
In accordance with another embodiment of the
invention means are provided for viewing the document and for
projecting an image thereof onto a moving photosensitive
surface. A means provides relative movement between the
document and the viewing means selectively at one of a plurality
of desired speeds. A means associated with the viewing means
9~3
provides selectively one of a plurality of desired projected
image magnifications. A drive means as described with respect
to the previous emhod~nent is utilized to drive the relative
movement providing means.
In accordance with yet another embodiment of a
reproducing apparatus of this invention, an automatic condi-
tioning means is provided for automatically conditioning the
previously described r~lative movement providing means to
provide a base mode speed after it has finished operation at
a speed different other than base mode speed. Means preferably
are also provided for automatically conditioning the projected
image magnification providing means to provide a base modè
magnification after it has finished operation at a magnifica-
tion different ~from the base mode magnification.
Preferably, the automatic conditioning~means~ includes~
a switch means for switching between a first state wherein the
movement providing means and magnification~providLng means
are conditioned to provide a speed different from the base
speed and a magni~ication different from the base magnifiaation,
respectively.
Preferably, the relative movement providing means
cornprises a document advancing means, and means ar~e provided
responsive to the movement of the document advancing means
between positions overlaying a platen and off a platen for
setting the switch means in the first state. ~=
Referring now to Figure 1, there is shown by way
of example an electrostatographic reproducing machine 10 which
incorporates the apparatus 11 of the present invention. The
reproducing machine 10 depicted in Figure 1 illustrates the
-- 10 --
1 L~2398
various components utilized therein for xerographically
producing copies from an original. Although the apparatus
of the present invention is particularly well adapted for
use in an automatic xerographic reproducing machine 10, it
should become evident from the following description that it
is equally well suited for use in a wide variety of electrostato-
graphic systems and is not necessarily limited in its applica-
tion to the particular embodiment shown herein.
Basically, the xerographic processor includes a
rotatably mounted photoconductive drum P which is supported
upon a horizontally extended shaft 12. The drum is driven
in the direction indicated whereby its photoconductive surface
is caused to pass sequentially through a series of xerographic
processing stations.
The practice of xerography is well-Xnown in the art,
and is the subject of numerous patents and texts, including
Electrophoto~3e~ by Schaffert, published in 1965, and
XeroqraPhY and Related Processes, by Dessauer and Clark;
published in 1965. Therefore, the various processing steps
involved will be briefly explained below in reference to
Figure 1. Initially, the photoconductive drum surface is
uniformly charged by means of a corona generator 13 positioned
within a charging station located at approximately the 12 o'clock
drum position. The charged drum surface is then advanced
into an imaging station 14 wherein a flowing light image of
an original document to be reproduced is projected onto the
charged drum surface thus recording on the drum a latent
electrostatic image containing the original input scene infor-
mation. Next, subsequant to the exposure step in the direction
2~9~3
of drum rotation is a developing station 15 wherein the latenk
electrostatic image is rendered visible by applying an
electroscopic marking powder (toner) to the photoreceptor
surface in a manner well known and used in the art. The now
visible image is then forwarded into a transfer station 16
wherein a sheet of final support material is brought into
overlying moving contact with the toner image and the image
txansferred from the plate to the support sheet by means of
a second corona generator 16.
In operation, a supply of cut sheets are supported
within the machine by means of a paper cassette 17. A pair
of feed rollers 18 are arranged to operatively engage the
.
uppermost sheet in the cassette so as to first separate the
top sheet from the remainder of the stack and then advance the
sheet into the transfer station .in synchronous moving relation-
ship to the developed image on the photoconductive plate
surface. The motion of the fëed rollers is coordinated with
that of the rotating drum surface, as well as the other
machine components through the main drive system whereby the
support sheet is introduced into the transfer station in
proper registration with the developed toner image suppor-ted
on the xerographic plate. For further information concerning
this type of sheet feeding mechanism, reference may be had to
U. S. Patent No. 3,731,915 to Guenther.
After transfer, but prior to the reintroduction
of the imaged portion of the drum into the charging station,
the plate surface is passed through a cleaning station l9
wherein the residual toner remaining on the plate surface is
removed. The removed toner particles are collected within a
- 12 -
23~3
container where they are stored subject to periodic removal
from the machine.
Upon completion of the image transfer operation, the
toner bearing support sheet is stripped from the drum surface
and placed upon a moving vacuum transport 20 which serves to
advance the support sheet into a thermal ~using station 21
wherein the toner image is permanently fixed to the sheet.
The copy sheet with the fused image thereon is forwarded from
the fuser into a collecting tray 22 where the sheet is held
until such time as the operator has occasion to remove it from
the machine.
Normally, when the copier is operated in a conven-
tional mode, the original document to be reproduced is placed
image side down upon a horizontal transparent viewing platen
23 and the stationary original then scanned by means of the
moving optical system 24. The scanning system 24 fundamentally
consists of a lens 25 positioned below the right hand margin
of the platen as viewed in Figure 1, and a pair of cooperating
mova~le scanning mirrors 26 and 27. The lens is basically a
half-lens objective having a reflecting surface 28 at the
stop position to simulate a full lens system. The two mirrors
are slidably supported between a pair of parallel horizontally
aligned guide rails ~not shown). For a further description and
greater details concerning this type of optical scanning system
reference is had to U. S. Patent No. 3,832,057 to Shogren.
In practice, mirror 23, herein referred to as the
full rate scan mirror, is caused to move from a home position,
directly below the left hand margin of the platen to an end
of scan position below the opposite margin of the platen. The
- 13 -
2~98
rate of travel of the scan mirror is synchronized to the
peripheral speed of the rotating xerographic drum surace P.
The second mirror 24 is simultaneously caused to move in the
same direction as the scanning mirror at half the scanning rate.
As the two mirrors sweep across the platen surface, an image of
each incremental area thereon viewed by the scanning mirror
is reflected towards the second mirror which, in turn, redirects
the image back to the half lens system. The reflecting surface,
positioned at the lens stop position, reverses the entering
light rays and redirects the light rays back towards a
stationary mirror 29 positioned directly above the drum surface
at the exposure station 14. In this manner a flowing light
image containing the original input scene information is
focused upon the charged photoconductive plate.~
~ wind up spring (not shown) is provided to restore
the moving mirrors to a start of scan condition.
The copying apparatus 10 shown in Flgure 1 is pro-
vided with a aocument feeder 30. The document feeder 30 is
movable between a first storéd position adjacent to the viewing
platen 23 and a second operative position over the platen
surface. Commensurate with the positioning of the feeder
assembly over the platen, the moving optical system 24 is
locked in a position to view documents as they are advanced
by the document feeder over the platen and record a flowing
light image of the input information upon the moving photo-
conductive plate surface P.
Referring now more specifically to Figures 1 and 2,
there is shown the document feeding mechanism 30 associated
with the instant invention. During normal operations, that
- 14 -
39~3
is, when the moving optics are utilized to provide a flowing
light image of the stationary original, the document feeding
assembly is maintained in a stored position (as depicted by
the phantom lines shown in Figure 1) to expose the entire
platen surface area and thus provide a maximum working area
for the operator.
To initiate the moving document mode of operation,
the machine operator simply advances the document feeding
assembly 30 from the stored position to a document feeding
position with the feeding assembly extending over the left
hand margin of the piaten surface. Fundamentally, the document
~eeding mechanism is made up of two main sections which include
a stationary support bridge, generally referenced 31, and a
movable feed roller support section, generally referenced 32.
The bridge 31 is made up of two vertically extending end
support members which are securely anchored in the machine
frame and upon which is secured a horizontal span 34. The feed
roller support section 32 is slidably suspended from the
horizontally extended span 34 by means of a pair of parallel
aliyned rod-like guide rails 32 and 38 which are slidably
supported in bearings (not shown) affixed to the underside
of the bridge span. The document feed roll assembly is
thus suspended from the span so that it can be freely moved
back and forth from the home or stored position adjacent to
the platen 20 and an extended position over the left hand
margin of the platen surface.
In practice, at the start of the moving document
handling conversion cycle, the machine operator grasps a
lever arm 39 mounted on top of the bridge span and rotates the
i9~
arm in a clockwise direction as shown in Figure 20 The lever
arm is operatively connected to segmented pinion 41 which
meshes with a rack 42 secured to the feed roller assembly 32.
Movement of the arm in a clockwise direction causes tne movable
feed roller assembly to be advanced toward the fully extended
or operative position. Rotation of the arm in the opposite
direction produces the opposite result.
Manually moving the feed roller support assembly 32
to the extended position also physically closes the contacts
of a large document mode switch (not shown) causing a signal
to be sent to the main machine drive motor (not shown)
actuating the motor. At the same time, a signal is also sent
to the machine logic control system placing the machine in a
single copy mode of operation. This latter step is required
in order to move the op~ical system from its normal rest
position, which is the start of scan position at the left
hand end of the platen surface, to the end of scan position
beneath the now fully extended feed roll assembly. However,
~uring this initial conversion phase, no original is actually
being processed and there is, therefore, no need to feed copy
sheets through the copier. In point of fact, feeding a copy
sheet during the conversion phase would have a deleterious
effect on the various machine components as well as confusing
the machine programminy and registering system. To prevent
this occurrence, means 60, as shown in Figure l, are provided
for inhibiting the action of the paper feeder during the
period when the machine is being converted to the moving
document mode of operation. Means 60 also provide for locking
the optics at the end of scan position during the moving
39!3
original mode of operation~ Means 60 comprise a lock-out
mechanism which serves to both uncouple the drive shaft from
the main drive system and hold the optics rigidly in a fixed
position for viewing moving documents subsequently advanced
through the document eeding assembly 30.
Further details of the inhibitor and lock-out means
60 may be obtained by reference to
.S~ Patent 3~Q0,258, and UO S. Patent ~o. 3,877,804.
The movable document feed roller support section 32
of the document feeder assembly is provided with two sets of
co-axially aligned rollers comprising a first set of drive
rollers 50 mounted upon shaft 51 and a second set of hold down
drive rollers 52 mounted upon shaft 53. The two roller support
shafts are connected by mPans of a timing belt 54 whereby each
set of rollers is adapted to turn in coordination with khe
other set of rollers. Shaft 57 is arranged to extend beyond
the end wall 55 o~ the movable document feeder roll support
,
section 32 and has a gear 56 rotatably supported thereabout
by normally engaged wrap spring clutch 57. In operation gear
56 is adapted to move into and out of meshing contact with
the stationary dri~en gear 58 as the docum~nt feed roll
section is moved between its stored and fully extended position.
When placed in a fully extended position, as shown in Fig. 2,
the gear 56 meshes with gear 58 thus causing both the document
~eed rollers 50 and the hold down rollers 52 to be rotated~
Directly below the stationary bridge and ad~acent to the
platen margin are a set of pinch rollers 59 (Fig. 1) which
are rotatably supported in the machine frame. The pinch rollers
are arranged in the machine frame so as to coact with the
- 17 ~
~ 2398
feed rollers 50 when the document feeder 30 is in the operative
position so as to advance a document introduced therebetween.
In operation, the document is moved past the viewing domain
of the now fixed optical assembly 24 and then into the pinch
between the hold down rollers 52 and the platen 23 surface.
The hold down rollers 52 serve to hold the document in sliding
contact with the platen surface as the original is being moved
past the optics and to feed the document after it leaves the
pinch of rolls 50 and 59.
The rolls 50 and 52 in the feeder 11 shown are
continuously driven during machine operation even when no
sheet is being fed.
The machine which has been discussed thus far is
:
similar in many respects to the aforenoted Xerox 3100 LDC
copier. It is capable of operating in~a number of modes
including a scanning mode wherein a stationary original is
scanned by the moving optical system 24 as well as a moving
original mode wherein the original itself is moved in
synchronism with the peripheral velocity of the drum and the
optical system is held stationary. This latter approach is
useful only in a single copy mode in the apparatus described;
however, it facilitates the copying of originals having a size
larger than the platen.
In accordance with the present invention yet another
mode of operation is provided for a reproducing machine. This
additional mode of operation comprises a reduction mode wherein
the image on the original is reduced in size by the optical
system for projection onto the photosensitive surface whereby
the image which is transferred to the sheet of ~inal support
- 18 -
material is similarly reduced in size. In accordance with
the reproducing machine of this invention, the reduction mode
is accomp]ished by a moving original exposure system.
For the reduction mode of operation it is necessary
to translate the lens 25 to change the conjugate distance
~etween the lens and the object or image planes. Further,
it is necessary to advance the document past the fixed optics
24 at a velocity greater than the peripheral velocity of the
drum P.
In accordance with a preferred embodiment of the ;
present invention, the previously noted optical system of the
Shogxen patent is modified to provide for lens translation
and the insertion of an add mir~or 60 into the optical path
to change the platen 25 to lens conjugate. The optical system
which is utilized herein is similar in most respects to that
descxibed in United S~ate~ Patent
4,Q29,409 to Spinelli et al. The optical system of
that application provides in addition to the optical system of
the Shogren patent an add reflector 60 which is selectively
positionable into the optical path to combine with the half
rate mirror 27 to form a reflection cavity and increase the
object distance for magnification change. The lens 25 is
movable relative to the optical path to adjust the conjugate
distance. of course, by the nature of a half (Catadioptric)
lens 25 with its associated reflector 28 the optical path
incident to the lens and reflected back through the lens is
at some angle relative to the lens axis. When a magnification
change necessitates repositioning of the lens, the repositioning
must take into account the divergence of the lens axis and
- 19 -
~ ~lh3 ~2 ~ 98
optical pathO In the optical 5ystem described in the aforenoted
Spinelli et al application, the insertion of the add reflector
60 displaces the optical path 61 to 61' and, therefore, the
lens 25 with its lens reflector 28 is shifted to satisfy
conjugate distance requirements and to remain centered on the
optical (principal ray) path.
It is a unique feature of this optical system that
the add mirror 60 does not form part of the scanning optical
arrangement so that no adjustment is necessitated in the drives
for the scanning mirrors irrespective of which magnification
mode is selected. The provision of an add mirror 60 independent
of the scanning optical system, which may be positioned in and
out of the optical ray path of the scanning optical system
provides a further advantage by reducing the mass of the
scanning mirror assembly as compared with the prior art. The
optical system 24 proposed herein is far superior to the prior
art since during the scanning operation the full rate and
half rate carriages carry but a single mirror 26 and 27
respectiveIy thereby providing a minimized scanning mass
and reduced dynamic problems.
Having thus described the basic outline of an
exemplary reproducing apparatus 10 in accordance with this
invention, attention will now be directed to specific elements
o the apparatus which enable it to carry out the reduction
mode of operation.
Referring now to Figures 2 through 4, the drive
system for the document feeder 30 is shown in greater detail.
The drive system includes a first pair o meshing gears 56 and
58 which comprise a low speed gear pair. The gear 56 on the
- 20 -
~2~9~
roll shaft 51 is rotatably supported thereabout and connected
thereto by a wrap spring clutch 57 of conventional design
such as the Series 15 clutches available from Reell Precision
Manufacturiny Company, St. Paul, Minnesota. The clutch 57
shown includes a boss element B which is pinned to the shat
51, a spring (not shown) is wrapped about a boss (not shown)
on gear 56 and i5 connected between the boss element B at one
end and the detent collar C at its other end. The spring is
arranged to normally wrap tightly about the boss of the free
wheeling gear 56 to engage the gear 56 to the shaft 51. Further
details of the low speed gear pair and wrap spring clutch
arrangement can be found in the aforenoted Hoppner U. S. Patent
No. 3,877,804. The aforementioned Hewes et al patent also
describes in detail suitable wrap spring clutches. A stop
switch 90 is provided in the feeder head which has a pin 91
for engaging the detent collar to disengage the ~rive gear 56
from the roll shaft Sl in order to stop the rolls 50 of the
document feeder 30. When the collar C is engaged by the pin
91, the spring inside the collar unwraps so as to withdraw it
from engagement with the boss of gear 56 which then free wheels.
In accordance with an embodiment herein additional
progressively higher speed gear pairs are provided on the
respective drive 93 and roll shafts 51. In the embodiment
of Figures 2 - 4, a single additional gear pair 70 and 71
is provided~ The gear 71 on the drive shaft 93 is pinned
thereto, The gear 70 on the roll shaft 51 is rotatably
supported with respect thereto by means of a wrap spring
clutch in a manner similar to gear 56.
,~ , , ,
, ', , ~
Z~9~3
Both this clutch and the previously noted clutch
56 are of an overrunning type. The clutch 72 is normally
engaged and may be disengaged by the speed changing mechanism
catch 77 intercepting the detent collar C. When the clutch
72 is engaged, the clutch 57 is overrun so that the speed of
the mechanism is controlled by the high speed gear pair 70
and 71. To change to a lower speed as might be employed,
for example, or 1 to 1 copying or for a lesser reduction, the
catch 77 engages the detent collar C of the high speed clutch
72 thereby disengaging the high speed gears 70 and 71 from
the roll shaft Slo The shaft 51 is then rotated in accordance
with the speed imparted by the low speed gear pair S6 and 58
through the engaged clutch 57. In this situation the high
speed clutch 72 is not overrunning, but is disengaged.
Therefore, in accordance with the present invention
by providing ~dditional higher speed gear pairs and~ssociated
overrunning clutches, it i5 . possible to change the speed of
the drive rolls 50 of the document ~eeder 30 to the speed
imparted by the highest speed gear pair having an engaged
clutch. All lower speed gear pai~s and their clutches are
overrun.
The speed changing mechanism comprises a butterfly
type switch member 76 pivotally supported by the document
eeder cover 75. The detent collar catch 77 is also pivotally
supported by the document feeder cover and connected by means
of link 78 to the butterfly switch member 76. A spring 80
provided between the cover member 75 and the catch 77 biases
the catch into engagement with the detent collar C of the
high speed gear clutch 72. A lost motion slot 79 is provided
in the link 78 to account for motion of the catch member 77
- 2~ -
~z~
caused when its tip intercepts the detent collar C at a
position other than the catch position. The detent collar
will continue to rotate with the gear 70 and clutch 72 until
the tip of the catch intercepts the catch portion of the
detent collar as shown. The lost motion slot 79 allows for
movement of the catch member 77 during this period even
through the switch m~mber 76 itself has been fully actuated.
Th~ stop button 90 which is similar to that described
in U. S. Patent ~o. 3,877,804 includes an additional pin
member 92 for intercepting the detent collar C of the high
speed gear clutch 72. The rolls 50 may be stopped by depress-
ing the STOP button which disengages both the high speed gear
70 and low speed gear 56 ~rom the document feeder drive shaft
51.
A mode changing switch 88 is provided which is
secured to the document feeder cover 7S and which may be
intercepted by a pin 86 eccentrically mounted to the butterfly
switch actuator 76. The mode changing switch 8~ is utilized
to condition the apparatus 70 for the appropriate mode of
operation. For example, if the switc~ actuator 76 is placed
in the reduction position as in Figure 4A so that the high
speed gears 70 and 71 are engaged then the mode switch 88
would be closed which would cause the lens 25 and add mirror
60 to be positioned in the appropriate arrangement for
reduction copying shown in phantom in Figure 1. Similarly,
deactuation of the mode switch 88 when the document feeder
is moved o and on the platen or when the switch actuator
76 is moved to the non-reduction position would condition
the apparatus 10 to return to the 1 to 1 or other desired
,
,
~L~2~98
base mode of operation and cause the lens 25 and add mirror
60 to be positioned in their home positions as shown in
solid lines in Flgure 1.
Since it is believed that the reduction mode of
operation would be the least used mode, an automatic means for
returning the apparatus to the 1 to 1 mode or other base mode
has been provided. Automatic mode changing is provided in
the embodiment shown in Figures 1 - 4 when the document
feeder 30 is moved off and on the platen 23 following
reduction copying. This automatic mode changing is accomplished
in accordance with the embodiment shown,;by the pin 86 on the
switch actuator 76, being engaged upon movement of the
carriage off and~on the platen by a spring member 85 to
return the switch~actuator 76 to its normal mode position.
Referring to Figure 4A,~the speed changing
mechanism is shown with the document feeder 30 off the platen
and the switch actuator 76 in the reduction position. This
would occur if the documeni ~eedex is moved of~ the ~laten
while the switch 76 is in the reduction position. Upon
movement of the document feeder back onto the platen 23 for
either large document copying, stream feeding o~ documents,
or reduction copying, the leaf spring member 85 intercepts
the switch actuator pin 86 and causes the switch to rotate
to the base mode or lower speed position as shown in Figure
4B. The leaf spring member 85 is then deflected and passes
under the pin 86 as the carriage 32 continues its movement
onto the platen. In this manner it i5 not possible for the
document feeder 30 to be placed off and on the platen 23 with
~he apparatus 10 remaining in a reduction mode. The apparatus
- 2~ ~
398
would, upon the document feeder being placed again on the
platen, automatically convert to the base mode. `Therefore,
by incorporating a switch actuator return mechanism 85 and
86 in accordance with this invention the apparatus lO is
automatically conditioned for a base mode of copying upon
movement of the document feeder 30 off and on the platen
following a reduction copying run.
The automatic mode changing apparatus described
above is effective to change the mode of operation upon move-
ment of the document feeder 30 onto the platen 23 after it
has been moved off the platen. If the document feeder is
moved off the platen in the reduction mode, and it is then
: .
desired to use the scanning mode of oper~ation, the machine
logic would accomplish this mode change and move the lens
and add mirror to their appropriate home positions.
Alternatively, if desired, a mechanical type system similar
to the one described above could be utilized which woùld
automatically switch the switch actuator to the base mode
poæition upon movement of the document feeder off the platen.
This alternative approach will be described later by reference
Figures 9A and 9B.
In the apparatus lO thus far described only one
high speed gear pair 70 and 71 has been provided which in turn
provides only a single additional reduction mode. It is
possible, in accordance with the present invention, to
provide further modes of reduction at different values of
reduction or magnification by the use of additional gear pairs.
Referring to Figure 5, a drive system is shown
comprising a three speed system having three sets of gear
- 25 -
39~
pairs which impart increasing rates of speed to the document
feeder roll shaft 51. Three input gears 58', 71', and g5
are coaxially supported by the input drive shaft 93', and
th~ee output gears 56', 70', and 96, are rotatably supported
about the roll shaft 51' by means of overrunning wrap spring
clutches 57', 72', and 97. It does not matter which side of
the gear 56', 70', or 96 the wrap spring clutches 57', 72', and
97 are arranged since they all operate in the same fashion,
namely, engaging the gear to the shaft when the detent
collars are free to rotate and disengaging the gear from the
shaft when the detent collars~are engaged by a stop or
catch member.
The speed of the roll shaft 51' is governed by the
speed of the highest spaed gear clutch 57', 72', or 97, which
:
is engaged. Solenoids lOO~and lO} actuate catch members 99 and
98 for the high speed gear clutches 72' and 97. To obtain
the slowest speed both o the solenoid actuated stop mem ers
99 and 98 would engage their respective detent collars C to
disengage the respective higher speed gears 70' and 96 from
the roll shaft 51'. To provide the intermediate speed- only
the highest speed stop member 98 would engage the highest
speed gear clutch 97, thereby disengaging it from the roll
shaft 57'. The lowest speed gear clutch 57' would then be
overrun. To provide the highest speed the stop members 98
and 99 would be disengaged from all clutches. The highest
speed gear pair 95 and 96 through its engaged clutch 97
would govern the speed of the roll shaft 51' with the lower
speed gear pairs being overrun through their clutches.
- 26 -
~l~Z3~
In this manner it is possible, in accordance wi-th
the present invention, to provide an extremely simple drive
mechanism for a document faeder 30 which enables the selection
of a plurality of discrete speeds for the feeder so that the
feeder may operate for producing images at discrete magnifi-
cations or minifications by moving document exposure.
~ aving thus described an appropriate mechanism for
changing the speed at which the document feeder 30 will advance
documents past the fixed optical system 24, and for~automa-
tically returning the mechanism to its base position, attention
will now be dixected to the mechanisms for translating the
lens 25 to its appropriate position for reduction copying
and for positioning the add mirror 60 in and out of the optical
path.
Referring now to Figures 1, 6, and 7, there is shown
an apparatus 110 for translating the lens 25 and mirror 60
between their base magnification position (shown in solid
lines in Figure 1) and their reduction magnification position
(shown in Figure 1 in phantom). The apparatus 110 includes a
frame member 111 adapted to be mounted in machine 10 to
provide the arrangement shown in Figure 1. A pair of spaced
apart parallel guide rails 112 are secured to the frame member
and are inclined upwardly and laterally. A lens carriage 115
is provided which is slidingly and pivotally supported upon
the rails 112 by means of spherical bearings 116. The lens
is secured to the lens carriage by any conventional means.
This arrangement provides ~or relatively easy movement of
the lens carriage 115 along the rails 112 even though that
movement is inclined laterally and upwardly and the lens
carriage pivots.
- 27 -
z398
The use of spherical bearings 116 permits the lens
carriage to pivot with respect to the plane of the rails 112.
In this manner, it is possible to translate the lens 25
between its base position and its reduction position and
also to pivot the lens in order to redirect the optical path
in one or the other positions so as to avoid vignetting.
Vignetting comprises the loss of a portion of the image through
the interference in the optical path 61' of one or more members.
These members, for example, the mirror carriages or frame
elements in the optical cavity interfcre with the light paths
and block portions of them thereby reducing the quality of
:
the resulting image. The optical system 24 which has been
described is ad:pted for use in a highly compact machine.
With a compact optical system, it is d~ifficu1t to~ provide
multiple lens positions and an adcl mirror and other optical
elements and frames in an arrangement wherein vignetting will
not pose a serious problem.
To reduce the occurrence of vignetting, it has been
found desirable to tilt the lens 25 about a generally
horizontal axis or plane so as to redirect the light ray
paths 61' in order to minimize the interference of object:
in the optics cavity. Therefore, in accordance with the
embodiment shown, the lens carriage I15 is capable of tilting
about a generally horizontal axis between a range of orienta-
tions. The orientation of the lens 25 as shown at the
respective end of travel positions of carriage 115 is established
by means of adJustable stops 117 against which the carriage
is biased. Three adjustable screw type stops 116 or 117
supported by the frame 111 at the respective end of travel
- 28 -
l~Z398
positions serve to orient the plane of the lens carriage.
In the embodiment shown in Figure 7, the lens 25
in the base mode position (shown in phantom) is oriented at
4~ ~egrees to the vertical V. In the reduction mode position
(shown in solid lines), however, in order to reduce vignetting
caused by the full rate mirror 26, the lens 25 has been tilted
about the horizontal axis so that it is at an angel of ~ - X
with respect to the vertical V.
Since the spherical bearings 116~allow the lens
carriage 115 to freely pivot about a horizontal axis while
riding on the rails 112, pads 119 are provided on at least
one side of the carriage to limit~its ran~ge of pivotal motion
to a reasonable range required or~changing~the lens orienta- -
tion. The pads 119 are secured to~the lens carriage 115~ and are
spaced a desired amount above the rails 112 so as to restrict
:: : ,
the degree to which the carriage may be pivoted with respect
to the plane of the rails.
In order~to bias the lens carriage 115 against the
stop~s 117 at its respective end of travel positions, a
compliance mechanism 120 has been devised. The compliance
mechanism 120 in conjunction with the drive system 130 is~
~ffective to blas the lens carriage 115 firmly against the~
stop members 116 or 117 so that it will achieve its desired
orientation and be free of movement due to vibration or other
causes.
The drive system 130 for the lens translation
apparatus 110 comprises a motor 131 connected by means of a
timing belt 132 to a capstan 133 secured to shaft 134 journaled
or rotation adjacent one of the rails 112. A second capstan
- 29 -
~z~g~ ,(
135 coaxially mounted to the shaft 134 is connected by means of
a timing belt 136 to a third capstan (not shown) which is
secured to shaft 138 journaled for rotation the the frame 111
adjacent the opposing side rail 112. A drive pulley 139 is
also coaxially mounted to each of the shafts 134 and 138,
adjacent one end of each of the respective rails 112. Adjacent
the other end of each of the respective rails 112, an idler
pulley 140 is rotatably supported by the frame 111. An
endless drive cable loop 141 is provided about each respective
drive pulley 139 and corresponding idler pulley 140 adjacent
each o the rails 112. Each cable loop 141 includes a ball
member 142 secured to the cable.
The carriage is connected to the drive cable 141
by means of the compliance mechanism 120 which comprises
spaced apart leaf springs 121 mounted at each side of the lens
carriage 115. Each spring has a slot 123 through which the
drive cable 141 passes. The ball member 142 is trapped
between the respective leaf springs 121 and 122 and provides
the driving engagement between the cable 141 and the carriage.
When the lens carriage 115 is to be advanced in one direction,
the ball abuts the leaf spring 121 or 122 opposing that motion
and causes the carriage to advance until it reaches the
adjustable skop members 117.
The rnotor 131 is driven for a desired interval
following the interception of the stop mernbers by the carriage.
This additional driving interval causes the leaf spring 121
or 122 to deflect and bias the carriage 115 against the stops.
When the carriage 115 is advanced in the other direction, the
opposing leaf spring 121 or 122 is engaged by the ball 142
- 30 -
35~8
of the drive cable 141 and the carriage is caused to advance
to the opposing stops 117~ The motor is again driven
for an interval following such engagement to deflect the
o~posing leaf spring to provide the requisite bias of the
carriage against the stops.
Switches 150 and 151 are provided which sense the
end of travel positions of the lens carriage 115 for shutting
of the motor l31 at the approprlate time. The switches 150
and 151 may also be used to sense jams in the translation
mechanism and ~or conditioning the~apparatus 10 for copying
in the base mode or reduction modes, respectivély.
The lens carriage 115 is provided wl~th a compliance
mechanism 160 to prevent it from binding up as it travels
along the spaced apart parallel rails 112. ~The~compliance
mechanism is provided at one end~of the carriage. The ~ -
carriage 115 as previously stated supports spherical bearings
I16 for sliaing engagement with the rails 112. ~The compliance
device 160 comprising two leaf springs 151 secured~to the main
carriage member 162 at one end and secured at their other end
to a bearing~support member 163 which is spaced from the main
carriage 162.~ The leaf springs 161 provide for side to
side compliance since they permit the bearing 116 in support
163 to deflect toward and away from the other bearing 116
which is supported in the main carriage member 162. The
spring members 161 do not, however, permit movement of
the bearing support 143 out of the plane of the carriage 115.
In this manner, binding associated with lens translation
is avoided since the leaf spring supported bearing member
163 is compliant with respect to changes in the distance
between the rails 112.
.
31 -
, . . .
9~
A mechanism is also provided for translating the
add mirror 60 from its inoperative position out of the
optics path to its operative position for providing the
previously described reflection cavity in accordance wlth
the Spinelli et al optical system. The add mirror 60 is
~upported by a pivotally mounted carriage 171 comprising a
horizintally extending support member 172 and two side
members 173 pivotally secured to the frame assembly 111. An
adjustable stop member comprising screw 174 is prGvided for
intercepting a pin 175 secured to one of the pivotal carriage
side members 173. The stop member 174 is effective to
accurately set the operable position of the mirror 60. The
pivotal carriage 171 is arranged to pivot about a substantially
horizontally extending axis.
The drive system 180 for the pivotal carriage 171 -
comprises a cable 181 secured at one of its ends to the shaft ~-
13~ and adapted to be wraped thereabout, and to a hub portion
176 of a pivotal carriage side member 173 at its other end.
A spring 182 is interposed in the drive cable to provide
compliance. An idler pulley 183 secured to the optics frame
111 is utilized to appropriately direct the drive cable.
The carriage 171 is spring biased toward its inoperative
position by means of a spring 184 secured to the optics frame
111 at one end eccentrically to the hub 176 at its other end.
Upon rotation of the shaft 134 the drive cable 181 connected
to the add mirror carriage 171 is coiled up on the shaft,
thereby pivoting the mirror 60 to its operable position
against the action of the return spring 184. A single motor
131 is utilized to both drive the lens carriage 115 and the
- 32 -
2~
add mirror carriage 171. The compliance spring 182 is
provided since the mirror 60 will be pivoted to its operable
position prior to the lens 25 reaching its reduction position.
When the mirror carriage 171 a~uts the stop 174 the spring
182 continues to expand as the drive shaft 134 continues to
coil up the cable while advancing the lens carriage. In
this fashion a single drive motor 131 can be utilized to drive
both optical elements 25 and 60 even though the time periods
required to completely translate them do not coincide.
- It has been noted above that the lens is arranged to
translate both upwardly and laterally. The upwardly
movement of the lens is a function of the optics geometry and
aids in reducing vignetting. The lateral movement of the
lens is for the purpose of moving the edge of the resulting
image on the copy sheet into proper registration on the copy
sheet. It is not essential in accordance with the present
invention to maintain a common registration edge on the
copy sheet for both the base and reduction modes of operation.
In the disclosed optical system changing the
conjugate distance effects changes in the projected image
; magnification according to the following relationship:
-
- 33 -
~1 .
s s ~c
~ ~ - --
wherein:
TC - Total Conjugate
f - Lens Focal Length
m - Magnification
f + m - Object Conjugate
~: Cos ~ ,'
~: f ~ fm~ - Image~Conjugate
, co L
:,
Angle betw:een~optical axis and
lens~a~is~
The con~ugate changing means in accor~dance wlth~
thls:invention has~been~descrlbed:as~bei~ng posltloned~on~ the :
object side of the lens, however, it should be apparent that
:
if desired conjugate changing means could be employed on the
image side o~ the lens ;~ :
Referring now to Figures 9A and 9B, there is shown
an alternate embodiment of a drive selection mechanism 200 in
accordance with the present invention. In accordance with
this embodiment, a slide type switch member~201~is slidably
supported by the document eeder cover 7~. A detent collar
catch member 202 is pivotally supported by the slide switch . :
member 201 at 203. A spring 204 serves to bias the catch
member 202 about the pivot 203 in a clockwise direction. A
stop portion 205 of the catch member 202 serves to limit the
- 3~ -
2~
rotation of the catch about the pivot 203 in the clockwise
direction.
The document feeder cover 75 which supports the
speed selection mechanism 200 is in turn supported by the
feed roller support section 32 (shown in Figure 2) and moves
therewith on and off the platen. For purposes of clarity,
the feed roller support section is not shown in Figures 9A
and 9B.
Figure 9A shows the document feeder in its position
overlying the platen. The slide switch 201 position and catch
member 202 positions shown in solid lines correspond to the
selection of base mode pro~ected image magnification, whereas
the slide switch and catch member positions shown in phantom
correspond to a reduction mode position. It is apparent
that when the switch 201 is in the reduction modé position the
:~ :
catch member 202 is completely disengaged from the clutch
72 so that clutch ~ngages the high speed gear pair 70 and 71
to the feed rollers. When the catch 202 is engaged to the
clutch as shown in solid lines, the high speed ge~r pair is
disengaged from the feed rollers. The spring 204 also provides
compliance in the event that the catch member should engage
the detent collar of the clutch at a higher position than
the catch position.
The slide switch 201 includes a triangular shaped
protrusion 206. A spring detent 207 secured to the cover co-
operates with the protrusion to hold the switch 201 in either
desired position, namely, base mode or reduction mode. The
slide switch 201 also includes a leg 209 serving a dual
purpose. The leg 209 serves to actuate or deactuate a mode
39~
changing switch 208. When the slide switch 201 is in the
base mode position, the mode selection switch 208 would be
actuated as shown in solid lines. This would condition the
lens 25 and add mirror 60 to be positioned in the appropriate
arrangement for base mode copying as shown in solid lines
in Figure 1. Similarly, deactuation of the mode switch 208
when the document feeder is moved off the platen or when
the switch actuator 201 is moved to the reduction position
would condition the apparatus 10 to move the lens 25 and add
mirror 60 to their appropriate positions for reduction aopying
as shown in phantom in Figwre l.
~ s with the previous described arrangement~it is
believed that the reduction mode of operation would be the
least used mode and, therefore, an autGmatic means for returning
the apparatus to the base mode has been provided~ Aùtomatic
mode changing is provided in the embodiment shown in~Figures 9A
and 9B when the document feeder is moved off the platen
following reduction copying. This automatic mode changing
i8 accomplished in aacardance with the embodiment shown by
a pin 210 secured to the stationary support 34. The pin 210
engages the leg 209 of the switch actuator 201 upon movement
of the document feeder off the platen ta return the switch
actuator to its base mode position as shown in solid lines.
This operation is illustrated in Figure 9B wherein the document
feeder is shown in its off the platen position. The pin 210
engages the leg 209 and forces the slide switch to move to
its base mode position. This deactuates mode switch 208
thereby conditioning the apparatus for base mode copying.
In this manner it is apparent that upon movement of the
- 36 -
~ 23~98
.. . .
documerlt feeder off of the platen the switch actuator 201 is
automatically return~d to its base mode position. ~ ~:
:
While this invention has been described with reference ~:~
: to the structure disclosed herein, it is not necessarily ;~
confined to the details as set forth and this application is
intended to cover such modifications or changes as may come
within the scope of the following claims. ~
: ; ~:
;, , - :':
,
`: ~'':'
.,
~,
- 37 -
