Original transfer apparatus

In an original transfer apparatus, a pair of rollers around which a transfer belt is stretched and pressing rollers provided between the pair of rollers and adapted to press the transfer belt against the platen are held with each end portion of each shaft of the rollers being fixed to a frame of a body of the transfer apparatus so as to be attachable and detachable directly and separately. The fitting of these rollers is executed by fitting at least three end portions of the shafts of the pair of rollers and each end portion of each shaft of the pressing rollers to the frame from a side opposed to the platen of the frame of the body.

BACKGROUND OF THE INVENTION 
1. Technical Field of the Invention 
The present invention relates to an original transfer apparatus for 
automatically transferring an original to and discharging an original from 
a platen section of a copying apparatus, an image reading apparatus, a 
microfilm photographing apparatus or the like in which an image is 
exposed, read or photographed, and particularly to an original transfer 
apparatus provided with a transfer belt stretched between a pair of 
rollers so as to be opposed to the platen, and a suitable number of 
back-up rollers provided inside of the transfer belt and adapted to press 
the transfer belt in pressure contact with the platen section. 
2. Description of the Related Arts 
In such a kind of conventional apparatus, as a transfer means for 
transferring an original to and discharging an original from a platen 
section, usually a white belt is used. Therefore, after being used for a 
long time, sometimes the transfer belt becomes too soiled to be cleaned by 
a cleaner and a read-out image becomes also soiled. Accordingly, the 
transfer belt is exchanged with a new one at predetermined times. 
An art for easily exchanging a transfer belt is disclosed in Japanese 
Unexamined Utility Model Publication No. 62-25484. In this art, supporting 
holes for supporting a pair of rollers around which a transfer belt is 
stretched are provided in a frame of a device, and each of the holes is 
provided with an outwardly opened cut off portion, so that a shaft of each 
roller is inserted through the cut off portion into the supporting hole, 
and by fitting the shaft into a bearing and then fitting the bearing into 
the supporting hole. 
Further, apparatus are known in which bearing portions for supporting a 
pair of rollers are detached from a frame of the apparatus by removing a 
cover, or in which after removing a cover, a front side plate constituting 
a frame is detached and then a transfer belt is forwardly pulled out. 
Further, an apparatus is known in which a pair of rollers with a transfer 
belt stretched therearound, back-up rollers and the like are set into a 
frame of a belt unit, and this belt unit is adapted to be attachable to 
and detachable from a frame of the device. 
However, in the construction disclosed in the Japanese Unexamined Utility 
Model Publication, a cover covering the frame of the apparatus including 
the bearing portions has to be preliminarily moved away in order to detach 
the bearings for exchanging the transfer belt, so that troublesome 
operations are required. Further, other devices in which the transfer belt 
is detached after moving the cover away have the same disadvantage. 
Further, in a construction in which a belt unit is attached to and detached 
from the frame of the device, a frame of the belt unit has to be provided 
in addition to the frame of the original transfer device, so that the 
apparatus becomes disadvantageously expensive. 
Further, as shown in FIG. 1, a back-up roller a is formed of a rotation 
shaft b with a plurality of small rollers c fixed thereon and disposed 
inside of a transfer belt d. This back-up roller a is supported at the 
rotation shaft b thereof by a holder f fixed to a frame e for supporting 
the transfer belt d, and adapted to press the transfer belt d against a 
platen glass g by its own weight or the like. Thereby, the transfer belt d 
is in pressure contact with the platen glass g at some positions in the 
longitudinal direction to provide a transfer force, whereby a delivered 
original can be pulled on the platen glass g so as to be copied and 
discharged from the platen glass g. 
However, as shown in FIG. 1, a conventional holder is fitted to the frame 
such that an end thereof protrudes near the edge portion of the transfer 
belt d, and attention must be paid to ensure that the holder can 
sufficiently bear the rotation shaft b and at the same time prevent the 
end of the holder from interfering with the edge portion of the transfer 
belt d. 
However, since the transfer belt d is hardly supported by the back-up 
roller a, when it is driven, the end portion of the transfer belt d shakes 
between two supporting rollers h as shown in solid and imaginary lines. As 
a result, the end portion of the transfer belt d is apt to be in contact 
with an end face of the holder. Therefore, the transfer belt is apt to be 
worn out and damaged, and the life thereof becomes shortened. 
Such a shaking of the end portion of the transfer belt d remarkably occurs 
when the transfer belt d is driven both in the positive and negative 
directions, and further, when the transfer belt g moves in zigzag 
direction the trouble is also serious. 
SUMMARY OF THE INVENTION 
A main object of the present invention is to provide an original transfer 
apparatus in which a transfer belt can be easily exchanged without 
removing a cover, and which has a simple construction and can be 
manufactured at a low cost. 
Another object of the present invention is to provide an original transfer 
apparatus in which a tension can be given to a fitted transfer belt 
without losing simplified exchangeability of the transfer belt. 
A further object of the present invention is to provide an original 
transfer apparatus in which a transfer belt can be easily exchanged under 
presence of pressing rollers for pressing the transfer belt against the 
platen. 
A further object of the present invention is to provide an original 
transfer apparatus in which a supporting member for supporting pressing 
rollers are improved so as to prevent the end portion of a transfer belt 
from being worn out or damaged and thereby extend the life of the transfer 
belt. 
Other and further objects and features of the present invention will become 
apparent from the following description given with reference to the 
appended drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Now, some embodiments of the present invention will be described in the 
following with reference to the appended drawings. 
FIGS. 2 to 13 show a first embodiment of the present invention which is an 
original transfer device applied to a copying apparatus A capable of two 
side copying. 
As shown in FIG. 2, the copying apparatus A has a platen glass 2 on the 
upper surface. At one end of the platen glass 2, a metal original scale 3 
is provided. The original scale 3 has calibrations (not shown) indicating 
the position of each size of original to be mounted by hand, and projects 
above the platen glass 2, thereby functioning as a positioning member for 
positioning an original. Numeral 3a indicates a positioning surface for 
executing such positioning of an original. In this embodiment, the 
positioning surface 3a is always above the platen glass 2. However, it may 
be so constructed as to project above the platen glass 2 only when 
required. 
On the upper surface having the platen glass 2 of the copying apparatus A, 
an original transfer apparatus B is provided with its rear end portion 
being hinged to the apparatus A so as to be opened and closed (not shown). 
As a result, the original transfer apparatus B is opened and closed and 
functions as an original cover for urging an original mounted by hand on 
the platen glass 2 to be copied. Further, the original transfer apparatus 
B in the state of covering the platen glass 2 can automatically transfer 
an original onto the platen glass 2 and automatically discharge the 
original from the platen glass 2. 
At the upper part of the original transfer apparatus B, an upper original 
tray 11 for feeding originals and a lower original discharge tray 12 are 
provided. As shown in FIGS. 2 and 8, the original discharge tray 12 is 
formed as a recessed portion in the upper surface of the body of the 
original transfer apparatus B, and has a discharge opening at the front 
side through which an original is discharged. A paper feed section 14 is 
provided at the right side of the original discharge tray 12. The original 
tray 11 is fitted by a bracket 15 to the paper feed section 14 so as to 
form a downward slope toward the paper feed section 14. Further, the 
original tray 11 has a side guide 20 of a centering type movable in 
accordance with the size of an original. In the paper feed tray 14, 
pick-up rollers 16 for downwardly feeding an original from the original 
tray 11, a parting section comprising parting rollers 17 and a parting pad 
for parting and delivering the downwardly fed originals one by one, and a 
pair of feed rollers for holding and securely feeding the original 
delivered from the parting section are provided successively along a lower 
paper feed guide 21 disposed in continuation with the original tray 11. 
An original stopper 31 is provided at a position directly before the 
parting rollers 17. The original stopper 31 is fixed to a pivotal shaft 34 
which is acted on by a keep solenoid 32 (FIG. 4). Usually, the original 
stopper 31 is at an original receiving position protruded above the lower 
paper feed guide 21, receives originals which are set to provide a setting 
feeling and aligns the leading edges of the originals. When the solenoid 
32 is turned on, the original stopper 31 retracts below the lower paper 
feed guide 21 against a force of a spring 33. 
The pick-up rollers 16 and the parting rollers 17 are both formed of rubber 
and positioned directly at both sides of a center line of an original 
transfer path (FIG. 4). 
An original pressing member 22 is provided above the right and left pick-up 
rollers 16. The original pressing member 22 is formed of a plate spring 
secured to the pivotal shaft 23. On the pivotal shaft 23, a solenoid 24 
and a recoiling spring 25 act on the pivotal shaft 23. The original 
pressing member 22 is normally pivoted upwardly by the pulling force of 
spring 25. However, when the solenoid 24 is turned on, the pivotal shaft 
23 makes pivotal movement against the force of the spring 25 so as to move 
the original pressing member 22 downwardly. Thereby the original pressing 
member 22 resiliently presses the originals set in the original tray 11 
against the pick-up rollers 16 so that a transfer power of the pick-up 
rollers 16 can securely act on the lowest original. 
In the early stage of feeding originals newly set in the original tray 11, 
a preliminary original transfer operation is executed for a predetermined 
time with the original pressing member being operated and the original 
stopper 31 being raised to the original receiving position. As a result, 
even if the lowest one of the originals set in the original tray 11 does 
not reach a predetermined position because of interference of the pick-up 
rollers or the like, the lowest one of the originals can be surely 
delivered to the original stopper 31 by the abovementioned preliminary 
transfer operation, and all the originals are aligned. At this time, the 
original stopper 31 is moved downwardly, so that the originals can be 
transferred. 
Without such operation, the foremost originals on the lowest one reach the 
parting section earlier than the lowest one and the lowest one is pulled 
out, and thereafter the lowest one reaches the parting section and is 
pulled out, thus causing multiple paper feed. 
Between the original stopper 31 and the parting section, a front parting 
plate 35 is provided. The front parting plate 35 is secured so as to form 
a downward slope from the front of the parting section toward the surface 
of the parting rollers 17. And the leading edge of the front parting plate 
35 is close to a portion directly before the contact position between the 
parting rollers 17 and the parting pad 18. The front parting plate 35 is 
formed of a metal base plate 35a and a resin upper plate 35b superposed on 
the metal plate 35a. Between the upper plate 35b and the parting rollers 
17, a necessary paper feed gap is provided. Further, a larger gap is 
provided between the base plate 35a and the parting roller 17. 
With such arrangement, when a set of originals delivered against the 
original stopper 31 and aligned by the abovementioned preliminary original 
transfer operation are fed, the front parting plate 35 guides the leading 
edges of the originals so as to be in alignment with the back surfaces of 
the base plate 35a and the upper plate 35b with the lowest originals 
advancing. Further, the lowest originals are easily pulled to the side of 
the parting section through the larger gap between the base plate 35a and 
the parting rollers 17. The number of these lowest originals is larger 
than that of the originals capable of being subjected to a sufficient 
parting operation at the parting section. However, these lowest originals 
are parted through the smaller gap between the upper plate 35b and the 
parting rollers 17 into original sets each consisting of an adequate 
number of originals and they are pulled to the parting section. The 
parting operation at this time is applied to the small number of originals 
parted by the base plate 35a and therefore it can be easily executed. And 
if some originals have not sufficiently parted, an adequate number of 
originals can be easily pulled to the parting section because some 
originals slip due to flexibility of the upper plate 35b. 
Accordingly, the front parting plate 35 can part originals into original 
sets each consisting of a rather small number of originals and easily 
deliver the same. In this case, the flexibility of the upper plate 35b can 
be optionally determined by selecting the material and the thickness 
thereof. 
The parting pad 18 is formed of rubber having a large friction factor, and 
is embedded in a part of the lower surface of a pad holder 36. The parting 
pad 18 and the pad holder 36 are pushed by a spring 37 to be in pressure 
contact with the parting rollers 17. Thereby, when a small number of 
originals are fed through the front parting plate 35 to the parting 
section, the parting pad 18 hinders, from above, the originals from going 
ahead, so that only the lowest originals which are in contact with the 
parting rollers having a large transfer power are parted and pulled. 
The original pressing members 22, the front parting plates 35 and the 
parting pads 18 are positioned respectively on the transfer center lines 
of the pick-up rollers 16 and the parting rollers 17 arranged at both 
sides of the center line in the direction of the transfer path so that 
they can surely act on an original subjected to a strong transfer force of 
the pick-up rollers 16 and the parting rollers 17. Further, with such 
arrangement, since the points of action of the original pressing members 
22, the front parting plates 35 and the parting pads are all symmetrically 
positioned, an original to be transferred can be prevented from skewing. 
The pair of feed rollers 19 are straight rollers and adapted to hold an 
original delivered from the parting section through the whole width so as 
to surely feed the same. 
At the time when an original reaches the pair of feed rollers 19 and is 
transferred, the pick-up rollers 16 and the parting rollers 17 are stopped 
in order to prevent a new original from being delivered from the original 
tray 11. 
Therefore, in this embodiment, the pick-up rollers 16, the parting rollers 
17 and the pair of feed rollers 19 are driven by a paper feed motor M1 
(FIG. 2), and an electromagnetic clutch CL1 is provided on the drive shaft 
of the parting rollers 17 (FIG. 3) so that the movements of the parting 
rollers 17 and the pick-up rollers 16 in interlocked connection therewith 
can be stopped at a suitable time. Further, a one way clutch 43 is 
provided between each of the pick-up rollers 16 and the parting rollers 17 
and each of their drive shafts 41, 42 respectively. As a result, even if 
the operation of the pick-up rollers 16 and the parting rollers 17 is 
stopped, they are driven through idling as long as an original to be 
transferred by the pair of feed rollers 19 is in contact with them so that 
the original transfer operation is not hindered. 
At a part of the pick-up roller 16, an empty sensor S1 is provided for 
detecting whether originals are set in the original tray 11, and when the 
empty sensor S1 detects originals, the original transfer operation can be 
executed. Directly downstream of the parting section, a paper feed sensor 
S2 is provided for detecting whether an original is delivered from the 
parting section. And when the paper feed sensor S2 detects an original, a 
predetermined time after the original is surely held between the pair of 
feed rollers 19, the original pressing member 22 is upwardly moved and the 
electromagnetic clutch CL1 is turned off to stop the drive of the pick-up 
rollers 16 and the parting rollers 17. Downstream of the pair of feed 
rollers 19, a U turn path 51 is provided for guiding the original to be 
transferred from this side of the original scale 3 toward the platen glass 
2. At a part of the U turn path 51 near the original scale 3, a pair of 
timing rollers 52 are provided. And in continuation with the U turn path 
51, a transfer belt 53 is provided on the original scale 3 and the platen 
glass 2. 
The pair of timing rollers 52 and the transfer belt 53 are driven by a main 
motor M2 which is a reversible motor. However, the pair of timing rollers 
52 can be stopped at suitable times independently of the transfer belt 53 
by turning on and off an electromagnetic clutch CL2 provided in a 
transmitting system thereof. The pair of timing rollers 52 once first 
receives the original fed from the pair of feed rollers 19, thereby 
aligning the leading edge of the original with a nip portion of the timing 
rollers 52 and correcting the skew of the original. Thereafter, the pair 
of timing rollers 52 are re-driven in timed relation to the copying 
operation of the copying apparatus A and thereby delivers the 
position-corrected original to the continuously driven transfer belt 53. 
The transfer belt 53 is stretched by a driving roller 54 and a driven 
roller 55 both supported by a front and rear frames 65 of the body 13 of 
the original transfer device so as to be in line with the original scale 3 
and the platen glass 2. The front end of the driving roller 54 is 
detachably carried by a bearing 50 schematically shown in FIG. 5 secured 
to the front frame 65 of the body 13 of the original transfer device, 
while the rear end thereof having a passive gear 63 to be connected to the 
main motor M2 is supported by a holding portion such as 66 fixed to a 
fitting portion such as fitting plate 56 which is secured to an attaching 
portion of the rear frame 65 by screwnails 64 so as to be detachable and 
attachable from below (FIGS. 5 and 6). Thereby, the driving roller 54 is 
detachable and attachable by detaching and attaching the fitting plate 56 
and pulling and inserting the front end thereof out of and into the 
bearing fixed to the front frames 65, and in accordance therewith, the 
passive gear 63 comes in and out of engagement with the driving gear 67 
connected to the main motor M2. Further, the front end of the driving 
roller 54 can be detachably and attachably fitted to the front frame 65 in 
the same manner with that of the rear end thereof. 
If necessary, the front end of the driving roller 54 may be mounted on the 
frame 65 through a member similar to a fitting plate 56. However, with the 
abovementioned construction, the front end of the driving roller 54 can be 
detachable from the frame 65 only by pulling the same from the 
abovementioned bearing and the driving roller 54 can be easily detached. 
As shown in FIGS. 3 and 5, both ends of the driven roller 55 are 
respectively supported by fitting portions such as slide plates 57 
detachably and slidably fitted to the front and rear frames 65 of the body 
13 of the original transfer device. Therefore, the driven roller 55 is 
attached to and detached from the frames 65 by attaching and detaching the 
slide plates 57 to and from the frames 65. The slide plates 57 are 
slidably and detachably fitted to the frames 65 by holding portions such 
as bearings 58 for the driven roller 55 fixed on the slide plates 57 into 
downwardly opened L-shaped groove attaching portion 59 provided in the 
front and rear frames 65 respectively and engaging upwardly opened 
L-shaped groove engagement portions 60 with supporting pins 61 (first 
supporting portions) provided on the front and rear frames 65. In this 
fitted state, a force of a spring 62 is acted between each supporting pin 
61 and each slide plate 57 so as to pull each slide plate 57 rightwardly 
in FIG. 2. The slide plates 57, subjected to this pulling force of the 
springs 62, act to move the driven roller 55 rightwardly in FIG. 2 so that 
a tension is given to the transfer belt 53 and at the same time the fitted 
state of the driven roller 55 to the frames 65 is surely maintained. 
With the abovementioned construction, the transfer belt 53 can be easily 
attached and detached by attaching and detaching the driving roller 54 and 
the driven roller 55 from the body 13 of the original transfer device from 
below. Therefore, a stay 71 for connecting and strengthening the front and 
rear frames 65 of the body 13 of the original transfer device is provided 
above the stretched transfer belt 53. 
Further, inside of the transfer belt 53, back-up rollers 72, 76 are 
provided for urging each part of the transfer belt 53 against the platen 
glass 2 and thereby securing a transfer force. Rotation shafts 72a, 76a of 
the back-up rollers 72, 76 respectively are detachably held by resin 
holders 73 fixed to the inner surfaces of the front and rear frames 65 and 
the slide plates 57 so as to prevent the back-up rollers 72, 76 from 
hindering the attachment and detachment of the transfer belt 53. 
As shown in detail in FIGS. 5, 7 and 9, the holder 73 has a pocket portion 
73a into and from which the rotation shaft 72a can be resiliently attached 
and detached. The pocket portion 73a receives the rotation shaft 72a and 
holds the same movably in the vertical direction, so that the back-up 
roller 72 urges the transfer belt 53 against the platen glass 2 by its own 
weight. 
Especially, an end portion 73b of the holder 73 is adapted to be protruded 
by a suitable amount X3 into the inside of the transfer belt 53. Thereby, 
if the transfer belt 53 is driven in the positive and negative directions 
and the ends thereof are caused to shake or the whole of the transfer belt 
53 makes a rocking motion, the end parts of the transfer belt 53 are 
prevented from deviating from the end portion 73b of the holder 73 and 
contacting with the end face of the holder 73. Accordingly it is possible 
to prevent shortage of life of the transfer belt 53 caused by the friction 
and damage given to the end parts thereof through such contact between the 
end parts of the transfer belt 53 and the end face of the holder 73. 
Further, at both end portions of the driving roller 54 and a driven roller 
55, flanges 54a and 55a are provided so as to prevent rocking motion of 
the transfer belt 53 and thereby further surely prevent the end parts of 
the transfer belt 53 from contacting with the end face of the holder 73. 
The abovementioned amount X3 may be suitable determined within a range of 
that purpose. However, in the pocket portion 73a of the holder 73, the 
rotation shaft 72a of the back-up roller 72 is detachably received and 
held by force of two opposed hooked portions 73c. Therefore, if the pocket 
portion 73a is elongated by setting X3 at a large amount, the rigidness of 
the hooked portions 73c becomes high and the back up roller 72 is hard to 
be attached and detached. Accordingly, the end portion 73c is so shaped as 
to fulfill the amount X3 only at the upper portion thereof, as shown in 
FIGS. 5 and 9. 
When the transfer belt 53 is positively driven by the operation of the 
back-up rollers 72, 76, the transfer belt 53 feeds an original delivered 
from the pair of timing rollers 52 onto the platen glass 2, and discharge 
an original mounted on the platen glass 2. When the transfer belt 53 is 
negatively driven, it brings the original fed onto the platen glass 2 into 
contact with the positioning surface 3a of the original scale 3 by switch 
back, thereby positioning the original on the platen glass 2, or it 
refeeds the inverted original returning from a paper discharge and 
returning section 81 disposed at the left side of the original discharge 
tray 21 in FIG. 2 onto the platen glass 2 and positions the same for the 
executing a back side copying operation of two side copying. In this case, 
when a thin paper mode is set in accordance with the controlled amount of 
returning originals, the originals are brought back just to the position 
of the original scale 3 and positioned without pressing the same, and in 
other cases, the originals regarded as front side originals are urged 
against the original scale and compulsorily positioned. 
At a position at this side of the pair of timing rollers 52, a sensor S3 is 
provided for detecting an original fed from the pair of feed rollers 19. 
The pair of timing rollers 52 are adapted to be redriven a predetermined 
time after the sensor S3 detects the original, so that the timing of the 
abovementioned arrangement of the positions of edges of the originals and 
the copying operation of the copying apparatus is adjusted. Further, a 
predetermined time after the sensor S3 detects the original, that is, at 
the time when the original passes the original scale by a distance X0, the 
transfer belt 53 is stopped and driven in the negative direction, whereby 
the positioning of the original is executed by switch-back. 
A switch-back amount used for this positioning is so determined as to 
fulfill the relation X0&lt;X1. Accordingly, the original is tried to be 
switched back by an amount X1 larger than the distance X0 passing the 
original scale 3, and surely urged against the positioning surface 3a, 
thereby the positioning being executed. And the transfer belt 53 is 
excessively driven in the negative direction to switch back the original. 
However, the original urged against the positioning surface 3a is not 
further transferred in the negative direction but stretches itself owing 
to its own firmness and slips on the transfer belt 53, whereby no problem 
is caused. 
On the other hand, if the original is thin and feeble, it cannot stretch 
itself after it is urged against the positioning surface 3a, and is folded 
or finely wrinkled in a triangle space defined by the platen glass 2, the 
original scale 3 and the transfer belt 53. In order to prevent this, the 
abovementioned usual original positioning mode using switch-back is 
changed over to a thin original mode only when a thin original mode 
setting key (not shown) is set, and the original transfer amount required 
for the rear edge of the original reaching the position of the positioning 
surface 3a is found by setting the time after the sensor S3 detects the 
rear edge of the original and the transfer belt 53 is stopped at that 
time, whereby the positioning of the original is executed without 
switch-back. 
The size of each path between the two back-up rollers 72, 76, or between 
each back-up roller and any transfer means disposed in front of or behind 
the back-up roller is so determined as to be smaller than the smallest 
size of an original measured in the transfer direction. Thereby, a small 
sized original can be also surely transferred. However, the back-up roller 
76 at the side of the driven roller 55 has to be at a position close to 
the driven roller 55. Therefore, the back-up roller 76 is adapted to be 
supported by the abovementioned slide plate 57 together with the driven 
roller 55 and is attached and detached also together with the driven 
roller 55. For this purpose, a back-up roller holding portion 57a is 
integrated with the slide plate 57, so that the back-up roller 76 is 
supported by the holding portion 57a so as to be movable in the vertical 
direction. The back-up roller 76 is pushed downwardly by a spring 93 
(FIGS. 3 and 5) acting between the back-up roller 76 and the holding 
portion 57a, whereby the transfer belt 53 is urged against an edge of the 
original scale 3 at the side of the positioning surface 3 a. Therefore, 
such a trouble can be prevented that an original switched back or 
positioning goes back beyond the positioning surface 3a. 
In the transfer operation, the length of an original in the transfer 
direction can be determined based on the relation between the time from 
the time of detecting the leading end of the original to the time of 
detecting the rear end thereof and the original transfer speed. By 
combining thus obtained length of the original with original width data 
from a width sensor S4 provided in the way of the U turn path 51, the size 
of the original including whether the original is transferred in 
lengthways or sideways can be judged. This judgement is used in selecting 
a paper cassette and a copying magnification in the copying apparatus. 
In a paper discharge and return section 81, there is provided a U turn path 
82 in continuation with the platen glass 2 and reaching an original 
discharge tray 12. In the way of the U turn path 82. A contrarotating 
roller 83 is provided in the way of the U turn path 82. Further, a paper 
discharge roller 85 is provided at a paper discharge opening section 84 
opened to the original discharge tray 12. Further, a return path 86 is 
provided for returning an original from the middle of the U turn path 82 
along the contrarotating roller 83 onto the platen glass 2. 
The contrarotating roller 83 and the paper discharge roller 85 are driven 
simultaneously with the transfer belt 53 by the main motor M2. However, 
the driving system of the main motor M2 consists of a first driving system 
in which only rotations of the main motor M2 are transmitted as right 
rotations through a one way clutch, and a second driving system in which 
only contrarotations of the main motor M2 are transmitted and oil changed 
over through a one way clutch to right rotations, so that the 
contrarotating roller 83 and the paper discharge roller 85 are always 
rotated only in the right direction whether the main motor is rightly 
rotated or contratotated, that is, whether the transfer belt 53 is driven 
in the positive or negative direction. Two small contrarotating rollers 
87, 88 provided in pressure contact with the contrarotating roller 83 so 
that they are driven for urging an original along the contrarotating 
roller 83. 
At an entrance of the U turn path 82, a lower contrarotating guide 89 is 
provided for guiding an original transfer by the transfer belt 53 from the 
platen glass 2 onto the U turn path 82 and then between the contrarotating 
roller 83 and the small contrarotating roller 87. 
The original guided into the U turn path 82 is transferred by the 
contrarotating roller 83 and the small contrarotating rollers 87, 88. A 
changeover claw 91 is provided at the position where the return path 86 of 
the U turn path 82 branches. When the changeover claw 91 is at the 
position shown in solid line in FIG. 1, it guides the transferred original 
to the side of paper discharge opening 84 so that the original is 
discharged by the paper discharge roller 85 onto the original discharge 
tray 12. On the other hand, when the changeover claw 91 is at the position 
shown in an imaginary line in FIG. 1, it guides the transferred original 
to the side of the return path 86. 
Directly at this side of the small contrarotating roller 87, a paper 
discharge sensor S5 is provided. When the sensor S5 detects an original, a 
predetermined time after the detection, that is, before the original has 
passed the paper discharge roller 85, the rotation speed of the main motor 
M2 is lowered, whereby the original is prevented from flying onto the 
original discharge tray 12. And at the same time, through the detection of 
the original by the sensor S5, timings for driving the transfer belt 53 in 
the reverse direction and the like can be obtained. 
As shown in FIGS. 2 and 8, in the original discharge tray 12, wave-shaped 
original receiving ribs 12b, 12c, 12d are provided successively in the 
original discharging direction on a horizontal bottom surface 12a. These 
original receiving ribs are respectively disposed in correspondence with 
the sizes of originals in the transfer direction in such a manner that the 
peak of each rib is a little behind the position of the center of gravity 
of an original received by the rib. With such arrangement, a discharged 
original is transferred successively beyond the ribs by transfer power of 
the paper discharge roller 85 till it reaches a rib corresponding to the 
size of the original in the transfer direction. And when the discharged 
original reaches the rib corresponding to its size, it goes beyond the 
peaks of the ribs. However, since the discharged original is off from the 
paper discharge roller 85 and is no longer transferred before the position 
of the center of gravity of the discharged original goes beyond the peaks 
of the ribs, resisting force against the original transfer at the peaks 
overcomes the force of forward movement of the discharged original. 
Consequently, the original is settled with its rear end being a little 
apart from the rear wall of the original discharge tray 12 having the 
paper discharge opening 84, and any size of original is settled in this 
position. 
The rear original receiving rib 12d is formed to be low in consideration 
with the relation of position between the same and the original tray 11. 
Therefore, a resin film 92 is provided on the original tray 11 and a long 
original is lightly pushed on the original receiving rib 12d so that the 
rib 12d can serve similarly as the other original receiving ribs 12b, 12c 
do. 
As abovementioned according to this embodiment, the operation of exchanging 
the transfer belt 53 is carried out in the following steps: the automatic 
original transfer device B is opened upwardly; then the back-up roller 72 
supported by the holder 73 is taken out from the side of the lower surface 
of the original transfer device B, then the spring 62 giving a tension on 
the transfer belt 53 is detached from the slide plate 57, then by 
loosening the screw nails 64, the fitting plate 56 supporting the rear end 
of the driving roller 54 is detached from the frame 65 and pulled 
downwardly and at the same time the front end of the driving roller 54 is 
pulled out from the bearing thereof whereby the driving roller 54 is taken 
out; then, after the slide plates 57 supporting two ends of the driven 
roller 55 are displaced leftwardly in FIG. 2, the supporting pins 61 for 
the frame 65 are pulled out from the L shaped grooves 60 and the bearings 
58 are pulled out from the L shaped grooves 59; thereby the driven roller 
55 and the slide plate 57 are taken out from the body 13 of the original 
transfer device B, and at the same time the transfer belt 53 is also taken 
out therefrom and exchanged with a new transfer belt 53. 
The new transfer belt 53 can be fitted to the body 13 of the original 
transfer apparatus B by carrying out the abovementioned steps in the 
reverse order. 
In this embodiment, a tension is given to the transfer belt 53 by pushing 
the driven roller 55 through the spring 62. However, if the transfer belt 
53 formed of a resilient material is used and the driven roller 55 is 
fitted to the frame 65 in the same manner as the driving roller 54 is 
fitted, the driven roller 55 can be more easily detached from the original 
transfer apparatus B. 
Further, in this embodiment, as shown in FIG. 10, a magnet unit 95 is 
fitted adjustably in the vertical direction to a fitting bracket 94 fixed 
on the front frame 65 of the body 13 of the original transfer apparatus B. 
This fitting of the magnet unit is executed by penetrating fitting screw 
nails through long holes 95a provided in the magnetic unit 95 and securing 
the same. With such arrangement, by loosening the fitting screw nails 96 
and thereby making the magnet unit 95 to be attracted by a magnetic member 
fixed on the upper surface of the copying apparatus with the automatic 
original transfer apparatus B being mounted on the upper surface of the 
copying apparatus A, and then by tightening the fitting screw nails 96 and 
thereby positioning the magnet unit 96, the whole surfaces of the platen 
glass 2 and the transfer belt 53 are without fail in uniform close contact 
with each other when the automatic original transfer device is closed. On 
the contrary, the magnet unit 95 may be provided on the upper surface of 
the copying machine A with the magnetic member fixed on the automatic 
original transfer apparatus B. 
Further, as shown in FIGS. 10 and 12, in order to easily execute the 
adjustment of the position of the magnet unit 95 by means of the fitting 
screw nails 96 from outside of a cover 13a of the body 13 of the automatic 
original transfer apparatus B, magnet unit disposing portions provided on 
both sides of a hold portion 13b of the cover 13a are recessed below the 
outer surface to form recessed portions 97 and a hole for operating the 
fitting screw nails 96 is provided in the inner side wall of each recessed 
portion 97. Further, an auxiliary cover 99 for covering the recessed 
portion 97 is adapted to be attached or detached by engaging an engagement 
piece 99a upwardly protruding from the upper end of the auxiliary cover 99 
and an engagement piece 99b horizontally protruding from the lower end 
thereof with corresponding engagement holes 97a, 97b respectively provided 
in the recessed portion 97. 
Further, as shown in FIG. 13, in the lower portion of the positioning 
surface 3a of the original scale 3, a hooked surface having a horizontal 
surface a little lower than the upper surface of the platen glass 2 is 
provided. With this arrangement, when the original OD is transferred in 
the negative direction to be urged against the positioning surface 3a and 
positioned, the rear end of the original OD is received by a corner 
portion 3c of the hooked surface 3b and can be prevented from being 
inserted into a space if any, between the original scale 3 and the platen 
glass 2. Furthermore, since the horizontal surface of the hooked surface 
3b is formed of an elastic member 3c such as a rubber member adhered and 
secured to the leading end of the original scale 3, it also functions as a 
pad for eliminating a space between the original scale 3 and the platen 
glass 2, so that the original OD can be more surely prevented from being 
inserted into a space therebetween. However, if the horizontal surface of 
the hooked surface 3b can surely receive an original, there may be a 
little space between the original scale 3 and the platen glass 2. For 
ensuring such receipt of an original by the hooked surface 3a, it is only 
necessary that the horizontal surface of the hooked surface 3b is below 
the upper surface of the platen glass 2 as shown in the second embodiment 
of FIG. 14, or, if not below the same, an upward slope 3d extending from a 
position below the upper surface of the platen glass 2 to the horizontal 
surface is provided for guiding an original OD to the horizontal surface 
as shown in the third embodiment of FIG. 15. In FIG. 14, the leading end 
of the original scale 3 is vertically moved through the pivotal movement 
thereof about a shaft 3f. However, each of the abovementioned two cases of 
the horizontal surface of the hooked surface 3b can be applied to an 
original scale 3 either of movable type or of fixed type.