An electrographic apparatus comprising a main body, a manuscript discharge tray, a slit light exposure portion, a manuscript feed mechanism including upper and lower feed mechanisms, the upper feed mechanism being arranged movably with respect to the lower feed mechanism, a photosensitive body, a sheet manuscript edge guide, a thick manuscript edge guide and means for automatically changing the two edge guides in response to a movement of the upper feed mechanism with respect to the lower feed mechanism; the apparatus being constructed and arranged such that in the case of obtaining copies of a sheet manuscript the sheet manuscript is fed by the manuscript feed mechanism under a condition that the upper feed mechanism is mounted on the lower feed mechanism and scanned by exposed light by one time and in the case of obtaining copies of a thick manuscript a thick manuscript carriage on which is disposed the thick manuscript is fed by the lower feed mechanism under a condition that the upper feed mechanism is moved from the lower feed mechanism and scanned by exposed light by one time.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to an electrographic apparatus which can obtain 
copies of a thick manuscript and a sheet manuscript. 
2. Description of the Prior Art 
Various kinds of electrographic apparatuses have heretofore been proposed 
and used in practice. One of these conventional electrographic apparatuses 
is mainly used for obtaining copies of a thick manuscript such as books or 
the like, while the other electrographic apparatus is mainly used for 
obtaining copies of a sheet manuscript. 
In the electrographic apparatus mainly used for obtaining copies of the 
thick manuscript, in the case of obtaining copies of the sheet manuscript, 
the sheet manuscript is disposed on a manuscript carriage and urged 
against it by a manuscript holding cover. The manuscript carriage or a 
projection optical system is reciprocated for number of times 
corresponding to the number of sheets to be copied, thereby obtaining 
copies. In this case, the operation of opening and closing the manuscript 
holding cover in order to set the sheet manuscript on the manuscript 
carriage is troublesome in operation. In addition, wind pressure produced 
when the manuscript holding cover is opened and closed tends to displace 
or blow off the sheet manuscript set beforehand, thereby rendering the 
operation very inconvenient and bad in efficiency. In general, the kind of 
the manuscript to be copied belonging to the sheet manuscript is far 
larger than that belonging to the thick manuscript. As a result, the above 
is the important drawback inherent to the electrographic apparatus mainly 
obtaining copies of the thick manuscript. 
On the other hand, the electrographic apparatus mainly used for obtaining 
copies of the sheet manuscript is classified into one type in which the 
sheet manuscript is directly inserted into and passes through a light 
exposure portion so as to be scanned by exposed light and into another 
type in which if the sheet manuscript is introduced into the apparatus it 
is automatically set to a given position where it is repeatedly scanned by 
the exposed light for the number of times corresponding to the number of 
the sheet manuscripts to be copied and then is automatically discharged 
from the apparatus. 
The former type electrographic apparatus can insert the sheet manuscripts 
in succession into the light exposure portion and hence is very rapid in 
operation if compared with the above mentioned electrographic apparatus 
mainly used for obtaining copies of the thick manuscript and adapted to 
change a previous manuscript to the next manuscript after the previous 
manuscript has been scanned by the exposed light. 
In addition, the former type electrographic apparatus is not required to 
use a reciprocating mechanism for the manuscript carriage or projection 
optical system, so that the apparatus as a whole is simple in construction 
and can be manufactured in a less expensive manner. But, in the case of 
obtaining a plurality of copies from the same manuscript, the manuscript 
must repeatedly be inserted into the light exposure portion for number of 
times corresponding to the number of copies to be obtained, and as a 
result, the apparatus becomes very troublesome in operation and bad in 
efficiency. 
The latter type electrographic apparatus has the advantage that a desired 
number of copies can be obtained by inserting the sheet manuscript only 
one time into the apparatus. But, this apparatus has the drawback that the 
apparatus as a whole is complex in construction, that a manuscript feed 
path is complex in construction and hence is troublesome in feed operation 
and that the manuscript tends to be easily broken. 
The former type electrographic apparatus can obtain copies of the thick 
manuscript with the aid of a suitable auxiliary means. On the contrary, it 
is almost impossible to obtain copies of the thick manuscript by the 
latter type electrographic apparatus. To the electrographic apparatus 
mainly used for obtaining copies of the thick manuscript has been added a 
sheet manuscript feed mechanism which can automatically feed a sheet 
manuscript disposed on a manuscript carriage and automatically discharge 
it after a required number of sheets have been repeatedly scanned by the 
exposed light. But, such kind of sheet manuscript feed mechanism is 
complex in construction and large in size and hence is generally used only 
for an expensive high speed copying machine. 
The auxiliary means added to the former type electrographic apparatus 
mainly used for obtaining the sheet manuscript and operative to obtain 
copies of the thick manuscript comprises a sheet manuscript driving 
roller, its corresponding driven roller and an end driven roller 
independent of the driven roller and arranged at the outside of the driven 
roller, the end driven roller being co-operative with the driving roller 
so as to feed a light transmission thin plate for the thick manuscript and 
constructed such that in the case of obtaining copies of the thick 
manuscript the sheet manuscript feed driven roller is pushed aside or 
removed and the light transmission thin plate with the thick manuscript 
disposed thereon is held between the driving roller and the end driven 
roller so as to be fed and scanned by the exposed light. That is, the 
light transmission thin plate in such auxiliary means is fed at a given 
feed speed by means of a friction force produced between the driving 
roller and the end driven roller. But, in the case of obtaining copies of 
the thick manuscript by means of such auxiliary means, an operator is 
always required to hold down the thick manuscript by a pressure which is 
sufficient to prevent the thick manuscript from displacing or from rising 
during feed of the light transmission thin plate. As a result, 
unreasonable force is subjected to the light transmission thin plate while 
it is fed. The frictional force produced between the driving roller and 
the end driven roller for feeding the light transmission thin plate 
sandwiched therebetween becomes changed. As a result, it is impossible to 
maintain the given feed speed, thereby inducing a blur in copy or an 
inclined displacement of the light transmission thin plate. As a result, 
in the case of using such auxiliary means, the operator is required to 
have a certain order of skill and operate with the greatest possible care. 
In addition, the end driven roller is projected from the surface along 
which the light transmission thin plate passes, so that the operator is 
also required to pay attention not to damage his finger or the manuscript 
got caught in the projected end driven roller. 
In the case of obtaining a plurality of copies from the same manuscript, 
the above mentioned operation must be repeated, so that the operation 
becomes more complex and the rate of damaging the precious manuscript 
becomes high. In addition, the separate need of the driven roller 
exclusively used for feeding the thick manuscript makes the apparatus 
complex in construction. 
The applicant has been proposed an electrographic apparatus which can 
eliminate the above mentioned drawbacks, that is, which can obtain copies 
of sheet manuscript and thick manuscript without damaging the manuscript 
in a simple manner, and which can obtain a desired number of copies with 
an extremely high efficiency by scanning the manuscript only one time by 
exposed light (U.S. Patent Application Ser. No. 26,760 and German Patent 
Application No. P29 15633.0). 
The proposed electrographic apparatus comprises a substantially rectilinear 
manuscript feed path including a slit light exposure portion through which 
is projected a manuscript image; a manuscript feed mechanism including 
upper and lower feed mechanisms arranged above and below said manuscript 
feed path at said slit light exposure portion with said manuscript feed 
path interposed therebetween, said upper feed mechanism being mounted 
movably with respect to said slit light exposure portion; and a 
photosensitive body for memorizing said manuscript image projected through 
said slit light exposure portion thereon as an electrostatic latent image; 
the apparatus being constructed and arranged such that in the case of 
obtaining copies of a sheet manuscript said sheet manuscript is fed by 
said manuscript feed mechanism under a condition that said upper feed 
mechanism is mounted on said lower feed mechanism and scanned by exposed 
light by one time and in the case of obtaining copies of a thick 
manuscript a thick manuscript carriage on which is disposed said thick 
manuscript is fed by said lower feed mechanism under a condition that said 
upper feed mechanism is moved from said lower feed mechanism and scanned 
by exposed light by one time, thereby producing on said photosensitive 
body an electrostatic latent image corresponding to said manuscript image 
and obtaining a plurality of copies on the basis of said electrostatic 
latent image. 
In this electrographic apparatus, use is made of a thick manuscript 
carriage comprising a flat transparent light exposure portion on which a 
thick manuscript to be copied is disposed, a carrying member which is 
driven without skipping by a thick manuscript feed mechanism of the 
electrographic apparatus and a member for determining a position of the 
thick manuscript at the light exposure portion; the light exposure 
portion, the carrying member and the position determining member being 
assembled into a single unit to form the thick manuscript carriage. The 
thick manuscript carriage is mounted on the thick manuscript feed 
mechanism with its one side parallel to the feed direction set along an 
edge guide provided on the electrographic apparatus. Then, a thick 
manuscript can be fed under a condition that the thick manuscript is 
positioned correctly. 
In such an electrographic apparatus, it is preferable to arrange an edge 
guide for determining a position of a side of the thick manuscript 
carriage outside an edge guide for determining a position of a side of a 
sheet manuscript. However, in such an apparatus the two edge guides must 
be changed over each other when a manuscript to be copied is changed from 
a thick manuscript to a sheet manuscript or vice versa. For this purpose, 
in said apparatus the edge guide for a sheet manuscript can be displaced 
with respect to the edge guide for the thick manuscript feed carriage, the 
latter edge guide being fixed. However, this change of edge guides is 
manually operated by a user and is often forgotten by the user. In this 
case, a position of a manuscript to be copied is not correctly set so that 
the manuscript cannot be recorded on a recording paper. In addition, this 
manual change requires a complicated and troublesome operation for a user 
of the electrographic apparatus. 
SUMMARY OF THE INVENTION 
An object of the invention is to provide an electrographic apparatus which 
obviates the above mentioned defects. That is, in the electrographic 
apparatus a user need not manually change over the edge guides when a 
manuscript to be copied is changed from a sheet manuscript to a thick 
manuscript or vice versa, so that there is no risk of mis-copying. Thus, 
the operation of the apparatus according to the invention is simple and 
not troublesome. 
A feature of the invention is the provision of an electrographic apparatus 
comprising a main body with a manuscript carriage; a manuscript discharge 
tray detachably mounted on said main body; a slit light exposure portion 
mounted on said main body and interposed between said manuscript carriage 
and said manuscript discharge tray, said slit light exposure portion 
defining a substantially rectilinear manuscript feed path and projecting a 
manuscript image therethrough; a manuscript feed mechanism including upper 
and lower feed mechanisms arranged above and below said manuscript feed 
path at said slit light exposure portion, said upper feed mechanism being 
arranged movably with respect to said lower feed mechanism; a 
photosensitive body for memorizing said manuscript image projected through 
said slit light exposure portion thereon as an electrostatic latent image; 
a sheet manuscript edge guide for determining a position of a side edge of 
a sheet manuscript; a thick manuscript edge guide for determining a 
position of a side edge of a thick manuscript, said thick manuscript edge 
guide being arranged outside said sheet manuscript edge guide in a 
direction perpendicular to said manuscript feed path; and means for 
automatically changing said two edge guides to be used in response to a 
movement of said upper feed mechanism with respect to said lower feed 
mechanism; the apparatus being constructed and arranged such that in the 
case of obtaining copies of a sheet manuscript said sheet manuscript is 
fed by said manuscript feed mechanism under a condition that said upper 
feed mechanism is mounted on said lower feed mechanism and in the case of 
obtaining copies of a thick manuscript a thick manuscript carriage on 
which is disposed said thick manuscript is fed by said lower feed 
mechanism under a condition that said upper feed mechanism is moved from 
said lower feed mechanism. 
Further objects and features of the invention will be fully understood from 
the following detailed description with reference to the accompanying 
drawings, in which:

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
FIG. 1 is a perspective view of an embodiment of an electrographic 
apparatus according to the present invention. In this embodiment, a 
plurality of copies can be obtained after a manuscript is only one time 
scanned by exposing light. 
Referring to FIG. 1, reference numeral 1 designates a main body which is 
provided along its upper surface with a manuscript feed path composed of a 
manuscript carriage 2, light exposure portion 3 and detachable manuscript 
discharge tray 4 rectilinearly arranged in the order as mentioned above. A 
sheet manuscript (not shown) is disposed on the manuscript carriage 2 and 
slidably moved toward the left as viewed in FIG. 1. The sheet manuscript 
is held between feed rollers in the light exposure portion 3. The feed 
rollers cause the sheet manuscript to pass through the light exposure 
portion 3 at a given speed and discharge it onto the manuscript discharge 
tray 4. This sheet manuscript feed path is rectilinearly constructed as 
described above for the purpose of feeding the sheet manuscript without 
any trouble. In addition, in the present embodiment, the front end of the 
sheet manuscript feed path viewed in the advanding direction of the sheet 
manuscript is inclined downwardly for the purpose of effecting insertion 
and feed of the sheet manuscript in an extremely natural manner. The 
manuscript carriage 2 is provided at its one side with an edge guide 5 
extending along the advancing direction of the manuscript and determining 
the position of the sheet manuscript to be inserted and serving also as a 
guide for the manuscript. 
The main body 1 is provided at its one side with an operation board 6 
including an electric source switch 7, dial 8 for determining the number 
of copies to be obtained, stop button 9, light adjusting knob 10 and 
various kinds of display lamps 11. The dial 8 for determining the number 
of copies to be obtained is rotated so as to set a desired number of 
copies (1 to 20 in the present embodiment) to be obtained when the 
manuscript is scanned one time by exposing light. The stop button 9 is 
pushed to stop the copying operation when it is started under a condition 
that the dial 8 is set to any erroneous number of copies. The light 
adjusting knob 10 is moved forwardly or backwardly so as to change the 
brightness of a fluorescent lamp (not shown) incorporated in the light 
exposure portion 3 and give a correct exposing light corresponding to the 
concentration of the manuscript. The display lamps 11 function to display 
the ON state of the electric source switch 7, start and end of the copying 
operation, presence and absence of a record sheet in a cassette to be 
described later, occurrence of jamming operation or the like. A record 
sheet supply cassette 12 encloses therein record sheets each having a 
given size and superimposed one upon the other. The cassette 12 is 
detachably mounted on one end surface of the main body 1. If it is desired 
to change the size of the record sheet, a cassette enclosing a record 
sheet having a desired size is selectively mounted on the main body 1. The 
main body 1 is provided at that end surface which is opposed to the end 
surface on which is mounted the cassette 12 with a discharge tray 13 for 
receiving a copy. One end of the discharge tray 13 is rotatably supported 
by the opposed side surfaces of the main body 1 and the free end of the 
discharge tray 13 is rotated upwardly about its supporting shaft and 
releasably locked to the main body 1. 
In the embodiment shown in FIG. 1, the manuscript feed path may be made 
horizontal and the manuscript carriage 2 may be provided at that side edge 
which is opposed to the edge guide 5 shown in FIG. 1 with another edge 
guide. 
FIG. 2 shows one embodiment of an interior construction of the 
electrographic apparatus shown in FIG. 1 in section. A seamless 
photosensitive drum 14 is rotatably journaled in the main body 1 and is 
rotated in a direction shown by an arrow when the electric source switch 7 
shown in FIG. 1 is made ON. In the present embodiment, the rotation of the 
photosensitive drum 14 causes a timing pulse to occur which controls 
various copying steps. At the same time, an erasion lamp 15 provided near 
the periphery of the photosensitive drum 14 is made ON and a cleaning 
brush 16 is rotated to erase the electrostatic latent image remained on 
the photosensitive drum 14 at the previous copying step and removed toner. 
The toner removed by the cleaning brush 16 is attracted toward a fan 17 
and seized by a filter 18, the fan 17 being rotated by another driving 
source at the same time as the rotation of the cleaning brush 16. The 
cleaning brush 16, filter 18 and fan 17 are arranged in a duct 19. 
In the present embodiment, the duct 19 is extended up to a transfer portion 
to be described later and a flow of air sucked by the rotation of the fan 
17 is used for the purpose of tearing off the record sheet closely adhered 
to the photosensitive drum 14 at the trasfer portion. As soon as the 
electric source switch 17 is made ON, a heater 21 enclosed in a fixing 
device 20 is energized to raise its temperature. 
The cleaning brush 16 is rotatably mounted on an arm 23 which is rotated 
about a supporting shaft 22 by means of an operating mechanism (not shown) 
to cause the cleaning brush 16 to bring into contact with and separated 
from the photosensitive drum 14. 
If the photosensitive drum 14 is rotated by one turn to erase the toner and 
electrostatic latent image remained on the surface of the entire surface 
thereof and becomes ready for starting the copying step, the above 
mentioned operating mechanism causes the cleaning brush 16 to separate 
from the photosensitive drum 14 and at the same time the erasion lamp 15 
becomes OFF. 
During the preparatory operation from the ON operation of the electric 
source switch 7 to the end of one rotation of the photosensitive drum 14, 
a sheet manuscript is disposed on the manuscript carriage 2 and slidably 
moved along the edge guide 5 toward the light exposure portion 3 until the 
front end thereof functions to operate a first microswitch 24. 
The first microswitch 24 functions to rotate through a clutch mechanism 
(not shown) a manuscript feed driving roller 25, thereby rotating a driven 
roller 26 and holding the front end of the sheet manuscript between the 
rollers 25, 26. As a result, the feed operation of the sheet manuscript is 
started. If the front end of the sheet manuscript causes a second 
microswitch 27 to operate, the above mentioned clutch mechanism is 
released. As a result, the manuscript feed driving roller 25 and driven 
roller 26 stop respective rotations to stop once the feed operation of the 
sheet manuscript held between the rollers 25, 26. This condition is 
maintained during the preparatory operation from the ON operation of the 
electric source switch 7 to the end of one turn of the photosensitive drum 
14. As soon as this preparatory operation is completed, the above 
mentioned clutch mechanism becomes driven again to cause the manuscript 
feed driving roller 25 and driven roller 26 to start their sheet 
manuscript feed operation again. 
The manuscript feed driving roller 25 is connected through the above 
mentioned clutch mechanism and a driving system (not shown) to the 
photosensitive drum 14 and rotated at a speed which is in synchronism with 
the peripheral speed of the photosensitive drum 14 to feed the sheet 
manuscript. 
If the feed operation of the sheet manuscript is started again, a 
fluorescent lamp 28 incorporated in the main body 1 turns ON to illuminate 
the manuscript. As a result, the sheet manuscript passing along a stage 
glass 29 is exposed to light. A light image of the manuscript scanned by 
the exposing light is projected through a projecting optical system 30 to 
the photosensitive drum 14. In the present embodiment, the projection 
optical system 30 is composed of a converging optical fiber array. As a 
result, the manuscript illuminating fluorescent lamp 28 may be composed of 
a slit-shaped fluorescent lamp having a high brightness and generating 
little heat, for example, and arranged near the manuscript scanning 
surface of the stage glass 29. 
The projection optical system 30 is provided at that side which is opposed 
to the fluorescent lamp 28 with a concave reflecting mirror 31 for 
illuminating the scanning surface of the stage glass 29 with a condensed 
light, thereby ensuring a required brightness and illuminating the 
scanning surface without casting a shadow thereon. 
The sheet manuscript passed over the stage glass 29 and scanned by the 
exposing light is held between a manuscript discharge driving roller 32 
adapted to be normally rotated as soon as the electric source switch 7 
shown in FIG. 1 is made ON and a driven roller 33 and discharged onto the 
manuscript discharge tray 4. 
During the lapse of time in which the sheet manuscript once stopped at the 
position of the second microswitch 27 is fed again and discharged onto the 
manuscript discharge tray 4, the photosensitive drum 14 which has 
completed the above mentioned preparatory operation is rotated in a 
continuous manner and the surface thereof is uniformly charged with ions 
delivered from a corona discharge device 34 arranged near the periphery 
thereof and then illuminated with the light image directed from the 
projection optical system 30 to produce on the surface thereof an 
electrostatic latent image corresponding to the manuscript image. 
This electrostatic latent image is developed into a visible toned image by 
means of a developing device 35 arranged near the periphery of the 
photosensitive drum 14. In the present embodiment, the developing device 
35 makes use of a magnet brush developing system using a developing agent 
formed of two components. The developing device 35 comprises a container 
36 in which are arranged a magnet roller 37 rotatable in a direction shown 
by an arrow and applying toner particles to the photosensitive drum 14, a 
mixing blade 39 for mixing the toner particles with a carrier in a 
developing agent 38, a doctor blade 40 for restricting the length of 
bar-shaped developing agent 38 adhered to the magnet roller 37 and a 
scraper 41 for scraping off the developing agent 38 which has completed 
its developing action and adhered to the magnet roller 37. On the 
container 36 is detachably mounted or made integral therewith a toner 
supplying container 43 containing toner particles 42 and provided at its 
lower end with a knurled roller 44. The knurled roller 44 is rotated so as 
to supply the toner particles 42 to the developing container 36 and hence 
always maintain any desired concentration of the toner particles in the 
developing agent 38. 
In order to develop the electrostatic latent image on the photosensitive 
drum 14 without deteriorating it, the carrier of the developing agent 38 
may be of one having a high resistance or the magnet roller 37 may be 
provided around its periphery with an insulating sleeve and either one of 
the magnet roller 37 and the insulating sleeve is rotated such that the 
developing agent 38 adhered to the photosensitive drum 14 is moved in a 
direction opposed to the rotating direction of the photosensitive drum 14. 
The developing device 35 may, if necessary, be provided with a developing 
electrode. In this case, a variable developing bias voltage is applied 
between the developing electrode and the photosensitive drum 14 so as to 
control the developing concentration. 
The toned image produced on the photosensitive drum 14 by means of the 
developing device 35 is transferred at a transfer portion to a record 
sheet by means of a transfer roller 45 urged against the photosensitive 
drum 14 under a suitable pressure. The transfer roller 45 is formed of an 
electrically semiconductive resilient material. Between the transfer 
roller 45 and the photosensitive drum 14 is applied a suitable bias 
voltage having the same polarity as that of the electrostatic latent image 
for the purpose of forming an electric field which can transfer the toned 
image to the record sheet without damaging the electrostatic latent image 
on the photosensitive drum 14. 
As described above, record sheets 46 are enclosed in the cassette 12 and 
superimposed one upon the other. These record sheets 46 are fed from the 
cassette 12 one by one by means of a supply roller 47 at a timing which is 
suitable for transferring the toned image to the record sheet 46 by the 
transfer roller 45. The sheet supply roller 47 is rotatably mounted on an 
arm 49 which can rotate about a supporting shaft 38 in two directions 
shown by arrows and urged against the record sheet 46 in the sheet feed 
cassette 12 at the above mentioned timing so as to supply it. The main 
body 1 is provided with a record sheet detecting sensor 50 for detecting 
presence or absence of the record sheet 46 in the cassette 12 mounted on 
the main body 1. The record sheet 46 supplied from the cassette 12 by 
means of the sheet supply roller 47 passes along a sheet guide 51 and is 
held between register rollers 52 and 53 which function to precisely 
correct the timing and feed speed of the record sheet 46. Then, the record 
sheet 46 passes along a sheet guide 54 and is fed between the 
photosensitive drum 14 and the transfer roller 45, thereby transferring 
the toned image produced on the photosensitive drum 14 to the record sheet 
46. 
The record sheet with the toned image transferred thereon is peeled off the 
photosensitive drum 14 by means of a peeling claw 55 and the flow of air 
sent through the duct 19 from the above mentioned fan 17. The peeled off 
record sheet passes along a sheet guide 56 and between a pair of feed 
rollers 57, 58 and through a record sheet feed path and is fed into the 
fixing devices 20, 20 arranged above and below the record sheet feed path. 
In the record sheet feed path between the transfer roller 45 and the feed 
rollers 57, 58 are arranged record sheet detecting sensors 59, 59 for 
detecting a jam of the record sheet. 
As described above, as soon as the electric source switch 7 shown in FIG. 1 
is made ON, the heaters 21 of the fixing devices 20 are energized to raise 
the temperature during the above mentioned preparatory operation and 
copying operation to a sufficiently high fixing temperature by the time 
that the record sheet on which the toned image is transferred reaches to 
the fixing devices 20. Subsequently, the fixing temperature is maintained 
at a suitable value by means of a control device (not shown). The heater 
21 is composed of a resilient zigzag shaped-wire extending along the 
record sheet feed path. Such zigzag shaped-wire can absorb its thermal 
expansion by its resilient bent portion and hence is prevented from being 
hung down. 
After the fixing operation, the record sheet is discharged onto the copy 
discharge tray 13 by means of a pair of discharge rollers 60, 61. In the 
record sheet feed path between the fixing device 20 and the discharge 
rollers 60, 61 is arranged a record sheet detecting sensor 62 for 
detecting jam of the record sheet. 
As soon as the electric source switch 7 shown in FIG. 1 is made ON, either 
one or both pairs of feed rollers 57, 58 and discharge rollers 60, 61 
become normally rotated. 
After the transfer step, the photosensitive drum 14 is further rotated to 
repeat the developing and transfer steps only, and as a result, a desired 
number of copies, in the present embodiment, at most 20 copies may be 
obtained on the basis of the same electrostatic latent image once produced 
on the photosensitive drum 14. In the case of obtaining a plurality of 
copies from one manuscript, the cleaning brush 16 is separated from the 
photosensitive drum 14 and the erasion lamp 15, manuscript illuminating 
fluorescent lamp 28 and corona discharge device 34 are kept under their 
inoperative condition. In the present embodiment, the manuscript 
illuminating fluorescent lamp 28 is made ON during a period from starting 
of the feed of the manuscript to the end of one rotation of the 
photosensitive drum 14. Immediately after the last transfer step of the 
final copy of the desired number of copies, the cleaning brush 16 is 
brought into contact with the photosensitive drum 14 and the erasion lamp 
15 is made ON. As a result, the toner particles and electrostatic latent 
image remained on the photosensitive drum 14 are erased so as to ready the 
photosensitive drum 14 for copying next sheet manuscript. In this case, if 
the next manuscript is not inserted into the light exposure portion 3, the 
photosensitive drum 14 is rotated for a given number of turns after the 
final transfer step and then is stopped and at the same time the rotation 
of the fan 17 is also stopped. 
During the above mentioned step of obtaining a plurality of copies, if the 
next sheet manuscript is inserted into the light exposure portion 3, this 
sheet manuscript undergoes a preparatory operation. That is, the front end 
of the sheet manuscript causes the first microswitch 24 to operate and is 
held between the manuscript feed driving and driven rollers 25 and 26 and 
then causes the second microswitch 27 to operate. Then, the sheet 
manuscript stands still waiting for completion of the step of obtaining a 
plurality of copies of the preceding manuscript. The final transfer step 
of obtaining a plurality of copies of the preceding manuscript is 
completed and then the toner particles and the electrostatic latent image 
remained on that part of the photosensitive drum 14 at which the transfer 
step has been effected are erased by the cleaning brush 16 and erasing 
lamp 15. 
If this cleaned portion arrives at the corona discharge device 34, it 
becomes operated to uniformly charge the photosensitive drum 14. 
Meanwhile, the next sheet manuscript standing ready for its feed operation 
is fed by the manuscript feed driving and driven rollers 25 and 26 such 
that the next sheet manuscript passes over the stage glass 29 is 
synchronism with that movement of the uniformly charged portion of the 
photosensitive drum 14 which arrives at the position opposite to the 
projection optical system 30. As a result, the next sheet manuscript is 
scanned by the exposing light in the same manner as described above. Thus, 
it is possible to obtain copies for a plurality of manuscripts without 
interruption. After the rear end of the preceding manuscript arrives at 
the light exposure portion 3, the operator can insert the next manuscript 
with a sufficient time margin. 
In the present embodiment, the dial 8 for determining the number of copies 
shown in FIG. 1 is of fixed one which is not automatically returned to its 
original position and the number of copies set beforehand is memorized in 
the apparatus at substantially the same time as the starting of the 
copying step. As a result, if in the case of obtaining a plurality of 
copies from a plurality of manuscripts it is desired to change the number 
of copies from a next manuscript, it is possible to set the number of 
copies of the next manuscript when the next manuscript is waiting for its 
feed operation at the light exposure portion 3 or when the copies of the 
preceding manuscript are being prepared. 
If the dial 8 for determining the number of copies is set to that number 
which is larger than a desired number and the step of obtaining a 
plurality of copies has been started, the top button 9 shown in FIG. 1 is 
pushed when the step of obtaining the copy corresponding to the desired 
numbers of copies is just started. Then, after the end of this step of 
obtaining this copy the just desired number of copies are obtained. 
As can be seen from the above, in the electrographic apparatus according to 
the present embodiment, if the electric source switch 7 is made ON and the 
preparatory operation which requires a rotation of the photosensitive drum 
14 by one turn is completed, then it is possible to obtain one copy 
everytime the photosensitive drum is rotated by one turn. If in the case 
of obtaining respective one copy from a plurality of manuscripts the 
manuscript from the second one is inserted into the light exposure portion 
3 before the end of one turn of the photosensitive drum 14 for the 
preceding manuscript, the manuscript from the second one once assumes a 
wait attitude and is fed as soon as the preceding manuscript completes its 
one turn to start the step of obtaining copies. As a result, in this case 
also it is possible to obtain copies without interruption. In this way, in 
the case of obtaining one copy, if the next manuscript is inserted into 
the light exposure portion after one turn of the photosensitive drum 14 
for the preceding manuscript, the copying step of this next manuscript is 
started when the front end thereof causes the second microswitch 27 to 
operate. In the case of obtaining a plurality of copies from a plurality 
of manuscripts, respectively, if the next manuscript is inserted into the 
light exposure portion 3 after the final copying step for the preceding 
manuscript, the copying step for this manuscript is started when the front 
end thereof causes the second microswitch 27 to operate. 
The above mentioned electrographic apparatus is capable of obtaining any 
desired number of copies by passing the sheet manuscript only one time 
along the rectilinear short feed path. As a result, the apparatus is 
simple in copying operation and an opportunity of damaging a valuable 
manuscript becomes extremely small. In the case of obtaining one copy and 
a plurality of copies from a plurality of sheet manuscripts, respectively, 
it is possible to obtain such number of copies without interruption, so 
that the apparatus is extremely high in efficiency. 
FIG. 3 shows the light exposure portion 3 shown in FIGS. 1 and 2 in greater 
detail. The manuscript feed driving roller 25 is composed of a plurality 
of spaced apart large diameter rollers to be described later and rotatably 
journaled in the main body 1 and connected through a clutch mechanism (not 
shown) to a driving system. The manuscript discharge driving roller 32 is 
also rotatably journaled in the main body 1, but is directly connected to 
the driving system with the clutch mechanism omitted. As described above, 
if the electric source switch 7 (FIG. 1) is made ON, the roller 32 becomes 
normally rotated. 
The manuscript feed driven roller 26 and discharge driven roller 33 are 
composed of a plurality of rollers rotatably mounted on roller shafts 70 
and 71, respectively. The roller shafts 70 and 71 are slidably engaged 
with bearing grooves 74 and 75 provided in a supporting body 73 which is 
rotatably mounted through a supporting shaft 72 on the main body 1. In the 
embodiment shown in FIG. 3, the supporting body 73 is composed of a 
rectangular casing open at its lower end and closed by an upper side 
manuscript guide member 77. The manuscript feed driven roller 26 and 
discharge driven roller 33 are urged against the manuscript driving roller 
25 and discharge driving roller 32 by means of a leaf spring 76 under the 
condition shown in FIG. 3. 
The supporting shaft 72 is located substantially on an extension line drawn 
from a rectilinear manuscript feed path formed by the manuscript feed 
driving and driven rollers 25 and 26 and manuscript discharge driving and 
driven rollers 32 and 33. The manuscript discharge tray 4 is provided with 
an edge 4a located at a position which is lower than the above mentioned 
extension line from the manuscript feed path by the thickness of the 
supporting body 73. As a result, if the supporting body 73 is rotated 
about the supporting shaft 72 through substantially 180.degree. to dispose 
it on the edge 4a of the manuscript discharge tray 4 as shown by dot and 
dash lines in FIG. 3, the manuscript feed driven roller 26 and discharge 
driven roller 33 are substantially aligned with the extension line drawn 
from the manuscript feed driving roller 25 and discharge driving roller 32 
to provide a thick manuscript feed path to be described later. 
The supporting shaft 72 and bearing members of the supporting body 73 
rotatably supported by the supporting shaft 72, are divided into two parts 
which are spaced apart from each other as viewed in a direction 
perpendicular to the manuscript feed direction by a distance which is 
sufficient to permit the thick manuscript to pass therethrough. In the 
position shown by full lines in FIG. 3, the supporting body 73 is closed 
at its lower surface by the upper side manuscript guide member 77 which is 
spaced apart from the stage glass 29 and from a lower side manuscript 
guide member 78 provided near the manuscript feed driving roller 25 to 
form a gap for defining the sheet manuscript feed path. The manuscript 
feed driven roller 26 and discharge driven roller 33 are projected from 
the upper side manuscript guide 77, so that in the position of the 
supporting body 73 shown by dot and dash lines in FIG. 3 the upper side 
manuscript guide 77 functions to prevent the roller shafts 70 and 71 from 
removing out of the bearing groove 74 and 75, respectively. The lower 
surface of the upper side manuscript guide member 77, that is, the surface 
opposed to the projection optical system 30 when the supporting body 73 is 
located at the position shown by full lines in FIG. 3 is provided at least 
on that range which corresponds to the effective picture surface of the 
projection optical system 30 with a white color painted portion having a 
reflecting power which is the same as that of a manuscript which is 
substantially white in color. The depth of the bearing grooves 74 and 75 
from the upper side manuscript guide 77 to respective bases 74a and 75a 
are determined such that in the case of feeding the thick manuscript with 
the supporting body 73 located at the position shown by dot and dash lines 
in FIG. 3, even if the manuscript feed driven roller 26 and discharge 
driven roller 33 are pushed downwardly against the action of the lead 
spring 76, these rollers 26 and 33 are slightly projected from the upper 
side manuscript guide 77. 
The thick manuscript feed mechanism for the electrographic apparatus 
according to the invention will now be described in greater detail with 
reference to FIGS. 4, 5 and 6. 
FIG. 5 shows the supporting body 73 rotated about the supporting shaft 72 
and disposed, inside out, on the edge 4a of the manuscript discharge tray 
4 so as to obtain copies of the thick manuscript. FIG. 5 shows one 
embodiment of the thick manuscript carriage adapted to dispose the thick 
manuscript thereon and carry it. FIG. 6 shows the mode of the thick 
manuscript carriage during its feeding on the manuscript feed driving 
roller 25. 
In the case of obtaining copies of a thick manuscript, the sheet manuscript 
edge guide 5 is rotated around its longitudinal axis to expose a thick 
manuscript edge guide 80. A method of changing over the edge guides 5 and 
80 one from the other will be described in greater detail. By means of 
these edge guides 5 and 8 both sheet and thick manuscripts are properly 
positioned at their side edge when these sheet and thick manuscripts are 
inserted into the light exposure portion 3. 
The manuscript feed driving roller 25 is composed of several short rubber 
rollers 25b spaced apart from each other and secured to a driving shaft 
25a rotatably journaled in the main body 1 and a pair of thick manuscript 
feed pinion gears 81 and 82 secured to those portions of the driving shaft 
25a which lie outside the rubber rollers 25b. The total length of the 
group of rubber rollers 25b is made one which is sufficient to feed a 
sheet manuscript having a maximum copy with allowable by the 
electrographic apparatus according to the present invention. The pinion 
gears 81 and 82 are arranged at those positions which do not prevent 
passage of the above mentioned sheet manuscript having the maximum copy 
width. 
The pinion gears 81 and 82 each has a pitch circle whose diameter is equal 
to a diameter of the rubber roller 25b. That is, if the thick manuscript 
is disposed on the thick manuscript carriage shown in FIG. 5 and fed, the 
speed of the thick manuscript is made equal to the feed speed of the sheet 
manuscript and to the peripheral speed of the photosensitive drum 14 (FIG. 
2). In addition, the pinion gears 81 and 82 are secured to the driving 
shaft 25a such that respective gear teeth are aligned with each other. 
A part of the outer periphery of each of the rubber rollers 25b for 
constituting the manuscript feed driving roller 25 is projected from the 
upper surface of the lower side manuscript guide 78 through a window 78a 
provided thereon. The pinion gears 81, 82 are also projected such that the 
upper end of a tooth base circle of the pinion gears 81, 82 is aligned 
with the upper surface of the lower side manuscript guide 78 or is made 
slightly higher than the latter. The rear end of the window 78a as viewed 
in the feed direction of the manuscript is slightly bent downwardly or 
chamfered for the purpose of preventing the front end of the sheet 
manuscript from engaging with the rear end of the window 78a. 
The lower side manuscript guide 78 is provided at its center part with a 
window 78b through which are projected actuators 24a and 27a of the first 
and second microswitches 24 and 27, respectively. 
The upper surface of the stage glass 29 is substantially aligned with the 
upper surface of the lower side manuscript guide 78. Between the upper 
surface of the stage glass 29 and the lower surface of the upper side 
manuscript guide 77 is formed the sheet manuscript feed path along which 
the sheet manuscript is fed. The upper surface of the stage glass 29 is 
located at a position which substantially coincides with an object 
surface, that is, a surface conjugate to an image surface of the 
projection optical system 30, more particularly, within a depth of field 
at the object side (preferably in the depth at a position nearer to the 
surface of the photosensitive drum 14). That is, the upper surface of the 
stage 29 is located at such position that in the case of copying a sheet 
manuscript there is no risk of out of focus even when the sheet manuscript 
is raised from the upper surface of the stage glass 29 and fed along the 
lower surface of the upper side manuscript guide 77 and that in the case 
of copying a thick manuscript there is no risk of out of focus even when 
the thick manuscript is disposed on the thick manuscript carriage shown in 
FIG. 5 and fed along a path which is higher than the sheet manuscript path 
by the thickness of the thick manuscript carriage. In order to prevent the 
front end of the sheet manuscript from catching the stage glass 29, that 
edge 29a of the stage glass 20 with which the manuscript makes at first 
contact is chamfered. In addition, the stage glass 29 is detachably 
mounted on the main body 1 so as to clean the illumination fluorescent 
lamp 28, projection optical system 30, reflecting mirror 31 or the like 
arranged below the stage glass 29. 
The manuscript feed driven roller 26 is opposed to the rubber roller 25b of 
the manuscript feed driving roller 25 and projected through a window 77a 
provided in the upper side manuscript guide 77. The manuscript discharge 
driven roller 33, like the manuscript feed driven roller 26, is also 
composed of a plurality of short-rollers each projected through a window 
77b provided in the upper side manuscript guide 77. The upper side 
manuscript guide 77 is provided with a window 77c at that portion which 
corresponds to the window 78b provided in the lower side manuscript guide 
78. 
The front and rear edges of the upper side manuscript guide 77 as viewed in 
the manuscript feed direction are so inclined that the sheet and thick 
manuscripts can be fed in a smooth manner. 
A bearing portion 73a for rotatably supporting the supporting body 73 and 
the supporting shaft 72 are located outside the extension line drawn from 
the thick manuscript edge guide 80 as shown in FIG. 4 so as to allow the 
feed of the thick manuscript carriage to be described later. 
The thick manuscript carriage will now be described in greater detail with 
reference to FIGS. 5 and 6. In the present embodiment, a thick manuscript 
carriage 85 is composed of a light transmissive plate 86 adapted to 
dispose a thick manuscript thereon, raised edges 86a and 86b provided at 
both sides of the light transmissive plate 86 and opposed in widthwise 
direction thereof and rack supporting edges 86c and 86d extending in 
parallel with the light transmissive plate 86 and made integral with the 
raised edges 86a and 86b, respectively. All of these plate and edges are 
formed of transparent plastics having a uniform thickness and made 
integral into one body. The rack supporting edges 86c and 86d are provided 
at their lower surfaces with racks 87 and 88 with their teeth facing 
downwardly, respectively. 
The light transmissive plate 86 has a thickness t which is sufficiently 
thick to make it mechanically rigid and geometrically flat and is 
sufficiently thin to maintain a manuscript surface within a range of the 
depth of field of the projection optical system 30 even when the 
manuscript surface is raised from the upper surface of the stage glass 29 
by an optical thickness of t/n where n is the refractive index of the 
light transmissive plate 86. Such light transmissive plate 86 may be 
formed of a transparent acryl plate having a thickness of 1 mm. 
The distance between the opposed raised edges 86a and 86b, that is, the 
width of the light transmissive plate 86 is of one which permits a thick 
manuscript having a maximum copy width allowable by the electrographic 
apparatus according to the invention to be disposed thereon. 
The light transmissive plate 86 is provided at one of ends in the 
lengthwise direction thereof with a raised end edge 90 for determining the 
position of the front end of the thick manuscript in its feed direction. 
The raised end edge 90 is partly broken away to form a notch 89. 
The notch 89 is located at a position which corresponds to the actuators 
24a and 27a of the first and second microswitches 24 and 27 and the base 
89a of the notch 89 is aligned with the front end of the thick manuscript 
which makes contact with the raised end edge 90. The height of the raised 
end edge 90 is so determined that when book, for example, is disposed open 
on the light transmissive plate 86 its thick cover does not make contact 
with the raised end edge 90. 
The teeth of the racks 87 and 88 are aligned with each other in a direction 
perpendicular to the lengthwise direction of the light transmissive plate 
86. The total length of the racks 87 and 88 is determined such that the 
racks 87 and 88 engage with the pinion gears 81 and 82, respectively, 
until the rear end of the thick manuscript having a maximum copy length 
allowable by the apparatus according to the invention has passed through 
the effective picture surface of the projection optical system 30. 
The height of the teeth of the racks 87 and 88 is so determined that the 
pitch line thereof is aligned with the lower surface of the light 
transmissive plate 86. 
As shown in FIG. 6, if the thick manuscript carriage 85 is disposed on the 
manuscript feed driving roller 25 so as to bring the racks 87 and 88 into 
engagement with the pinion gears 81 and 88 provided at both ends of the 
manuscript feed driving roller 25, a contact line between the rubber 
roller 25b of the manuscript feed driving roller 25 and the lower surface 
of the light transmissive plate 87 is aligned with the pitch line where 
the pinion gears 81 and 82 engage with the racks 87 and 88, respectively. 
As a result, the peripheral speed of the rubber roller 25b is equal to 
that of the pitch circle of the pinion gears 81, 82, so that the thick 
manuscript carriage 85 is smoothly fed at a given speed. 
If the racks 87 and 88 are formed of plastic molding obtained by the same 
mold, it is possible to align these teeth by merely aligning one end of 
the racks 87 and 88 with the end of the rack supporting edges 86c and 86d. 
In addition, the thick manuscript carriage 85 composed of the light 
transmissive plate 86, racks 87, 88, notch 89 and raised end edge 90 may 
be made of transparent plastics and made integral into one body. 
The operation of obtaining copies of a thick manuscript by means of the 
above mentioned thick manuscript carriage 85 will now be described with 
reference to FIGS. 2 to 6. 
In the first place, a thick manuscript to be copied is disposed on the 
light transmissive plate 86 of the thick manuscript carriage 85 with the 
manuscript surface faced downwardly and the front and side edges of the 
manuscript are brought into contact with the raised end edge 90 and side 
edge 86b, respectively. Then, the thick manuscript is urged against the 
thick manuscript carriage 85 such that the thick manuscript is closely 
contact with substantially total surface of the light transmissive plate 
86. The thick manuscript carriage 85 is slidably moved toward the light 
exposure portion 3 while the side edge of the thick manuscript carriage 
85, that is, the side edge of the rack 88 slightly makes contact with the 
thick manuscript edge guide 80. 
If the thick manuscript carriage 85 arrives at the light exposure portion 
3, the base 89a of the notch 89 causes the actuator 24a of the first 
microswitch 24 to be pushed, thereby starting the rotation of the 
manuscript feed driving roller 25. Then, the racks 87 and 88 are brought 
into engagement with the pinion gears 81 and 82, respectively, thereby 
starting the feed of the thick manuscript carriage 85. 
If the pinion gears 81, 82 cause the thick manuscript carriage 85 to be fed 
the base 89a of the notch 89 is urged against the actuator 27a of the 
second microswitch 27, thereby once stopping the feed of the carriage 85. 
Then, similar to the above described operation of obtaining copies of the 
sheet manuscript, the carriage 85 is fed again after a predetermined time 
has elapsed. At the same time, the manuscript illuminating fluorescent 
lamp 28 is made ON to project the image of the thick manuscript disposed 
on the thick manuscript carriage 85 through the stage glass 29 and 
projection optical system 30 onto the photosensitive drum 14. 
The front end of the thick manuscript carriage 85 which has passed over the 
stage glass 29 rides on the manuscript discharge driving roller 32 and is 
fed thereby. At this time, the rear half-portion of the thick manuscript 
is still scanned by the exposing light. As described above, the thick 
manuscript feed path composed of the manuscript feed driving roller 25, 
manuscript discharge driving roller 32, manuscript discharge drive roller 
33 and manuscript feed driven roller 26 makes one flat plane, so that the 
thick manuscript carriage 85 is effectively fed along this thick 
manuscript feed path. As a result, the thick manuscript disposed on the 
thick manuscript carriage 85 is not deviated from the depth of field of 
the projection optical system 30 and hence is effectively projected onto 
the photosensitive drum 14. 
As described above, the thick manuscript carriage 85 is fed by mutual 
engagement between the racks 87 and 88 on the one hand and the pinion 
gears 81 and 82 on the other hand. As a result, if the thick manuscript 
carriage 85 is urged against the thick manuscript feed path under a 
pressure which is sufficient to prevent disengagement between the racks 
and the pinion gears, it is possible to feed the thick manuscript carriage 
85 in an extremely positive manner. In addition, the engagements between 
the racks 87, 88 and the pinion gears 81, 82 are effected at the left and 
right sides with respect to the feed direction of the thick manuscript 
carriage, and the feed speeds at the left and right sides of the thick 
manuscript carriage are equal with each other, so that there is no risk of 
the thick manuscript carriage being inclined during its feed. The thick 
manuscript carriage 85 may be urged against the thick manuscript feed path 
under a pressure which is sufficient to prevent the thick manuscript from 
floating, as in the case of the conventional copying machines. As a 
result, in the case of obtaining copies of a thick manuscript by means of 
the electrographic apparatus according to the present invention, the 
operator can urge the thick manuscript against the thick manuscript 
carriage 85 for the purpose of preventing the thick manuscript from 
floating up and feed the carriage 85 in conformity with the operation of 
the electrographic apparatus, thereby effecting the copying operation in a 
positive manner. 
The above mentioned electrographic apparatus is capable of obtaining any 
desired number of copies of a manuscript by scanning it only one time by 
an exposing light. Therefore, the apparatus as a whole is made light tight 
such that the electrostatic latent image produced on the photosensitive 
drum 14 is effectively maintained, that is, the surface of the 
photosensitive drum 14 is prevented from being illuminated with any 
exterior light during a step of obtaining a plurality of copies. This 
light tight property of the apparatus can effectively be maintained when 
copies of a sheet manuscript are obtained by the supporting body 73 
covering the light exposure portion 3. But, in the case of obtaining 
copies of a thick manuscript, the supporting body 73 is rotated about the 
supporting shaft 72 to the position shown by dot and dash lines in FIG. 3. 
As a result, after the passage of the thick manuscript an exterior light 
may pass through the projection optical system 30 without hindrance. As a 
result, there is a risk of the electrostatic latent image once produced on 
the photosensitive drum 14 being erased by the incident exterior light. In 
practice, any exterior light on the order of indirect indoor illumination 
light does exert substantially no adverse effect upon the electrostatic 
latent image, but a light source, etc., for indoor illumination arranged 
directly above the electrographic apparatus does exert a remarkably 
adverse effect upon the electrostatic latent image. 
The present embodiment can provide a plurality of copies from a thick 
manuscript even under the above mentioned condition. 
For this purpose, when a thick manuscript disposed on the thick manuscript 
carriage has been completely scanned by the exposing light, the front end 
of the thick manuscript carriage 85 is made contact with a stopper 4b 
provided at a front end of the manuscript discharge tray 4 to stop the 
feed of the thick manuscript carriage 85. Moreover, the rear end portion 
of a light transmissive plate 86 of the thick manuscript carriage 85 is 
provided at that portion which is opposed to the stage glass 29 under the 
above described condition with a light interruptive portion 92 formed by a 
light interruptive treatment such as a black paint coating. 
As a result, after the thick manuscript 91 has been scanned by the exposing 
light, the light interruptive portion 92 functions to interrupt an 
incident of exterior light onto the photosensitive drum 14. If this 
condition is maintained until a step of obtaining a plurality of copies is 
completed, the electrostatic latent image produced on the photosensitive 
drum 14 is effectively maintained, thereby obtaining any desired number of 
copies without deteriorating their picture quality. If the stopper 4b is 
too high, there is a risk of the stopper 4b being struck by the thick 
cover of books, etc., and of the manuscript being displaced. Therefore, 
the height of the stopper 4b is made slightly higher than the thick 
manuscript carriage 85. 
The under surface of the light transmissive plate 86 is provided at an area 
outside the light interruptive portion 92 and outside a portion on which 
the thick manuscript 91 is disposed with a reflective portion painted with 
white color having substantially the same reflection factor as that of 
white part of a manuscript, which can avoid an undesired adhesion of toner 
to a portion of the photosensitive drum 14 and a record paper not 
corresponding to the black portion of the manuscript. 
As stated hereinbefore, the electrographic apparatus according to the 
present embodiment has a number of advantages. In the first place, the 
apparatus is simple and compact in construction. Secondly, it is possible 
to obtain a plurality of copies of a sheet manuscript and thick manuscript 
by scanning such manuscript one time only by an exposing light, so that 
the apparatus can be manipulated with a high efficiency. Third, the use of 
substantially rectilinear manuscript feed path, and the production of a 
plurality of copies by one time exposure of light ensure an extremely 
small rate of damaging the sheet manuscript. Fourth, since the manuscript 
feed path can easily be made open by rotating the supporting body 73, it 
is possible to confine the damage of the sheet manuscript to the minimum 
even when the light exposure portion 3 is clogged with the sheet 
manuscript. Fifth, since the combination of steps of obtaining copies 
renders it possible to effect the copying operation without interruption, 
particularly in the case of obtaining copies of a sheet manuscript the 
manuscript treatment becomes considerably high in efficiency if compared 
with the conventional electrographic apparatus for mainly obtaining copies 
of the thick manuscript. Sixth, even in the case of obtaining copies of 
the thick manuscript, the thick manuscript can be fed in a simple and 
precise manner and it is possible to obtain a plurality of copies by 
scanning the thick manuscript by one time only by the exposing light in 
the same manner as in the case of the sheet manuscript, whereby the 
apparatus can easily be operated in the same manner as the conventional 
electrographic apparatus for mainly obtaining copies of the thick 
manuscript in general. 
FIGS. 7A and 7B are perspective views showing an embodiment of a mechanism 
for changing edge guides 5 and 80 in an electrographic apparatus according 
to the present embodiment, in which FIG. 7A shows a case of copying a 
sheet manuscript 95 and FIG. 7B shows a case of copying a thick manuscript 
96 disposed on a thick manuscript carriage 85. The edge guide 80 for 
determining a position of a side edge of the thick manuscript carriage 85 
is fixed to the main body 1 while the edge guide 5 for determining a 
position of a side edge of the sheet manuscript 95 is provided so as to 
rotate the edge guide 80 about axes 101 and 102. The axis 101 is provided 
with a coil spring 103, by which the edge guide 5 for a sheet manuscript 
is biased so as to rotate as shown in FIG. 7B. A pin 104 is provided on a 
side surface of the edge guide 5 that is opposed to the manuscript feed 
mechanism. The pin 104 is, as shown in FIG. 8A, engaged with a curved 
recess 105 formed at a front edge of the supporting body 73 supporting the 
upper feed mechanism as shown in FIG. 8A. Therefore, when the supporting 
body 73 for the upper feed mechanism is closed, the engagement of the pin 
104 with the curved recess 104 rotates the edge guide 5 against the force 
of the spring 103 as shown in FIGS. 7A and 8A, whereby a surface 5A of the 
edge guide 5 determines a position of the side edge of the sheet 
manuscript 95 and guides it as shown in FIG. 9A. The weight of the upper 
feed mechanism including the supporting body 73 is made so heavy that the 
upper feed mechanism can press down the edge guide 5 against the force of 
the spring 103. If the weight of the upper feed mechanism is deficient, it 
is impossible to normally hold and transport the sheet manuscript 95 by 
driving rollers 25 and 32 between them and driven roller 26 and 33. The 
edge guide 5 should be constructed such that it protrudes below the top 
surface of the manuscript carriage 2 as clearly shown in FIGS. 7A and 9A, 
by which the sheet manuscript 95 is not held between the manuscript 
carriage 2 and the edge guide 5. 
In the case of copying the thick manuscript 96, the supporting body 73 of 
the upper feed mechanism is rotated about the shaft 72. This rotation of 
the supporting body 73 rotates the edge guide 5 about the axes 101 and 102 
with the aid of the force of the spring 103, by which the surface 5A of 
the edge guide 5 for a sheet manuscript comes off the manuscript carriage 
2 and the edge guide 80 for guiding the thick manuscript carriage 85 is 
exposed. The thick manuscript carriage 85 is guided with its side edge 
being in contact with the exposed edge guide 80. As shown in FIG. 9B, a 
side surface of the edge guide 80 is provided with a pin 106 which is fit 
to an arcuate slot 107. The arcuate slot 107 serves as a stopper for 
rotation of the edge guide 5, by which the edge guide 5 does not rotate 
further over a perpendicular position. 
When the supporting body 73 supporting the upper feed mechanism is rotated 
for copying the sheet manuscript 95, its curved recess 105 is brought into 
engagement with the pin 104, by which the edge guide 5 is rotated against 
the resilient force of the spring 103 to provide the condition shown in 
FIG. 7A. 
Thus, a user merely rotates the supporting body 73 supporting the upper 
feed mechanism, in response to which the edge guides 5 and 80 are 
automatically changed over one from the other. This operation is easy and 
can positively prevent mis-copying which may be caused by forgetting the 
changing. 
FIGS. 10 and 11 show another embodiment of the electrographic apparatus 
according to the invention. In this embodiment, the mechanism for changing 
over edge guides in response to the upper feed mechanism is different from 
that of the above described embodiment. Therefore, only the mechanism for 
changing over edge guides is described in detail hereinafter. In this 
embodiment, an edge guide for determining a position of a side of a sheet 
manuscript is provided rotatably about an axis 112. A manuscript carriage 
2 is provided with an elongated hole 113 for receiving this protruding 
edge guide 111. A tension spring 114 is provided between the edge guide 
111 and the main body of the apparatus so as to always bias the edge guide 
111 downwardly. An L-shaped lever 116 is rotatably provided about an axis 
115 on the main body. An end 116A of the lever 116 is engaged with the 
edge guide 111 and the other end 116B thereof is protruded above the 
manuscript carriage 2. The latter protruding end 116B of the lever 116 is 
pressed down, as shown in FIG. 10, by a front end of the supporting body 
73 supporting the upper feed mechanism when the supporting body 73 is 
closed. 
When a sheet manuscript is copied, the protruding end 116B of the lever 116 
is pressed down, as shown in FIG. 10, by the supporting body 73 so as to 
rotate the edge guide 111 clockwise about the axis 112 against the force 
of the spring 114 and to make the edge guide 111 protrude from the hole 
113 above the manuscript carriage 2. Thus, the edge guide 111 for a sheet 
manuscript is set. When the upper feed mechanism is rotated as shown in 
FIG. 11, the lever 116 is made free and the edge guide 111 is held under 
the top surface of the manuscript carriage 2 to expose a guiding side of 
an edge guide 80 for a thick manuscript carriage. 
FIGS. 12, 13 and 14 show still another embodiment of the electrographic 
apparatus according to the invention. In this embodiment, an edge guide 
120 for a sheet manuscript is attached to the supporting body 73 
supporting the upper feed mechanism. A protrusion 121 is provided on the 
front side of the supporting body 73. The protrusion 121 is provided with 
an ellipsoidal hole 122 through which a pin 123 having an ellipsoidal 
cross section is inserted. Both the ends of the pin 123 are adhered to the 
edge guide 120. Therefore, the edge guide 120 is moved up and downward in 
a plane of drawing of FIG. 13. When a sheet manuscript is copied, the 
supporting body 73 for the upper feed mechanism is placed upon the lower 
feed mechanism so that the edge guide 120 for the sheet manuscript is 
inserted in a groove 2A formed along a side edge of the manuscript 
carriage 2 to determine a position of a sheet manuscript. 
When the supporting body 73 is rotated and placed on the manuscript 
discharge tray 4 as shown in FIG. 14 for copying a thick manuscript, the 
edge guide 120 is brought under the supporting body 73 and a top surface 
of the edge guide 120 and a top surface 120A of the supporting body 73 are 
brought in one and the same plane. 
FIGS. 15 and 16 show another embodiment of the apparatus shown in FIGS. 12 
to 14. In this embodiment, an edge guide 130 for a sheet manuscript is 
attached to the supporting body 73 of the upper feed mechanism. A pin 132 
is inserted through a hole of a protrusion 131 protruding from a front 
edge of the supporting body 73 and both ends of the pin 132 are adhered to 
the edge guide 130. Thus, the edge guide 130 is rotated downward through 
an aperture 133 of the manuscript discharge tray 4. This prevents the edge 
guide 130 from protruding above the thick manuscript feed path. 
FIG. 17 shows still another embodiment of the electrographic apparatus 
according to the present invention. In this embodiment, an edge guide 140 
for a sheet manuscript is provided rotatably about an axis 141. Between an 
end of the edge guide 140 and the main body of the apparatus a tension 
spring is provided which rotates the edge guide 140 clockwise about the 
axis 141. This rotation is limited by a stopper 143. A reference numeral 
144 denotes a microswitch 144 having an actuator which is driven by a 
front end of the supporting body 73 for the upper feed mechanism. The 
output of the microswitch 144 is delivered to a solenoid driving circuit 
145, the output of which drives a solenoid 140 having a plunger coupled to 
the other end of the edge guide 140. When the supporting body 73 is closed 
for copying a sheet manuscript as shown in FIG. 17, the solenoid 146 is 
not energized so that the edge guide 140 is protruded above a top surface 
of the manuscript carriage 2 by the spring 142. When the supporting body 
73 is made open for copying a thick manuscript, the microswitch 144 is 
actuated, by which the solenoid 146 is energized. Then, the edge guide 140 
is rotated anticlockwise against a force by the spring 142. The edge guide 
140 is rotated to or below the top surface of the manuscript carriage 2 so 
that an edge guide 80 for guiding the thick manuscript carriage is 
exposed. 
FIGS. 18 and 19 show further embodiment of the electrographic embodiment 
according to the present invention. In this embodiment, a single edge 
guide 150 is commonly used as an edge guide both for a sheet manuscript 
and a thick manuscript. The edge guide 150 is displaced in a parallel 
manner in response to a rotation of the supporting body 73 for the upper 
feed mechanism. A reference numeral 151 denotes a microswitch actuatable 
by a front edge of the supporting body 73. The actuated microswitch 151 
energizes a solenoid 152. To a plunger of the solenoid 152 is pivotally 
provided an end of a lever 153. The lever 153 is provided rotatably about 
an axis 155 provided on a fixed member 154. The other end of the lever 153 
is pivotally provided on the edge guide 150. There is pivotally provided a 
second lever 156 on and between the fixed member 154 and the edge guide 
150, which comprises a parallel link mechanism. A compression coil spring 
157 is provided to the plunger of the solenoid 152. 
When a sheet manuscript is copied, as shown in FIG. 18, the actuator of the 
microswitch 151 is depressed down by the front edge of the supporting body 
73 so that the solenoid 152 is not energized. Under this condition, the 
edge guide 150 is displaced toward right in FIG. 18 by the action of the 
spring 157. When a thick manuscript is to be copied by rotating the 
supporting body 73, as shown in FIG. 19, the microswitch 151 is switched 
on to energize the solenoid 152. Then, the plunger of the microswitch 151 
is drawn back against the spring 157 so that the edge guide 150 is 
displaced toward left. As the levers 153 and 156 constitute a parallel 
link mechanism, the edge guide 150 is always moved in a parallel manner to 
the fixed member 154. 
The invention is not limited to the above described embodiments, but 
various modifications and alternations are possible. For example, although 
the electrographic apparatus was a type of obtaining a plurality of copies 
by only one exposure in the above embodiments, the present invention, of 
course, may be applied to an electrographic apparatus of conventional type 
in which a single copy is obtained by one exposure. Other modifications 
will be described hereinafter. 
For example, as means for detecting the insertion of the sheet or thick 
manuscript into the manuscript feed path, use may be made of a 
photoelectric switch, etc., instead of the microswitch. 
In addition, in the case of obtaining copies of the thick manuscript, the 
supporting body 73 has been rotated about the supporting shaft 72 and 
disposed on the edge 4a of the manuscript discharge tray 4. But, the 
supporting body 73 may be disposed on the base surface of the manuscript 
discharge tray 4 or supported by a suitable stopper. 
The manuscript discharge driving roller 32 composed of one elongate rubber 
roller may be composed of a plurality of short rubber rollers as in the 
case of the manuscript feed driving roller 25. Conversely, each of the 
manuscript feed driving roller 25, manuscript feed driven roller 26 and 
manuscript discharge driven roller 33 may be composed of an elongate 
rubber roller. In addition, use may be made of three or more than three 
pairs of the manuscript feed and discharge rollers instead of two pairs 
thereof. Similar to the manuscript feed driving roller 25, the manuscript 
discharge driving roller 32 may be provided at its each end with a pinion 
gear and hence it is possible to feed the thick manuscript carriage 85 
with the aid of two pairs of pinion gears. The use of the two pairs of 
pinion gears ensures a reduction of the length of the racks 87 and 88 of 
the thick manuscript carriage 85. In this case, the pinion gears are 
required to be secured to the manuscript discharge driving roller 32 such 
that the teeth of the pinion gears are so adjusted in direction with 
respect to the teeth of the pinion gears 81 and 82 of the manuscript feed 
driving roller 25 that the racks 87 and 88 can correctly engage with these 
pinion gears. 
In addition, the feed mechanism for the thick manuscript carriage 85 may be 
composed of a pair of rack and pinion gear instead of two pairs of racks 
and pinion gears as described in the previous embodiment. 
The racks 87, 88 may be arranged along the side surface of the thick 
manuscript carriage 85 and the corresponding pinion gears 81, 82 may be 
arranged at the side surfaces of the light exposure portion 3 or 
supporting body 73. In this case also, use may be made of a pair of rack 
and pinion gear. Instead of using the rack-pinion gears, use may be made, 
for example, of a rack-helical gear, perforation-sprocket wheel, magnet 
tape-magnet roller and the like. In addition, instead of using the 
seamless photosensitive drum 14, use may be made of a seamed 
photosensitive drum or screen photosensitive body for the purpose of 
effecting operation of obtaining desired copies. In this case, it is 
preferable to control each operation by means of a signal emitted in 
synchronism with the rotation of the photosensitive body. 
In the case of obtaining copies of the thick manuscript, the supporting 
body 73 may be removed from the manuscript feed path or may be rotated 
toward a direction perpendicular to the manuscript feed direction. In 
addition, the supporting body 73 may be rotated toward the manuscript 
carriage 2 so as to provide a rectilinear thick manuscript feed path. 
Alternatively, the manuscript feed driven roller 26 and manuscript 
discharge driven roller 33 may be composed of driving rollers as in the 
case of the manuscript feed driving roller 25 and manuscript discharge 
driving roller 32, that is, all of the rollers may be composed of driving 
rollers. Conversely, the rollers 26 and 33 provided for the supporting 
body 73 may be composed of driving rollers. 
Alternatively, the thick manuscript carriage 85 may be constructed such 
that it can hold the peripheral edge of the thick manuscript. In the case 
of obtaining a single copy by one exposure, the light interruptive portion 
92 may be preferably painted with white paint having substantially the 
same resistivity as a white manuscript, excluding a zone on which a 
manuscript is disposed. 
The mechanism of displacing an edge guide for a sheet copy in response to a 
movement of an upper feed mechanism is not limited to the above described 
embodiments, but various modifications and alternations are possible. For 
example, a mechanical link mechanism such bevel gears, wires, link 
mechanisms or the like may be used. Moreover, in the case of detecting a 
movement of an upper feed mechanism by a microswitch, photoelectric switch 
and so on and of displacing the edge guide on the basis of a detected 
signal, use can be made of a method using a linear solenoid, a method 
using a rotary solenoid utilizing gears, belts and the like, and a method 
using fluid. 
As described above, according to the electrographic apparatus, an edge 
guide for a sheet manuscript and an edge guide for a thick manuscript can 
be changed over automatically in response to a movement of upper feed 
mechanism so that no risk of mis-copying caused by forgetting of 
switching. In addition, a user is not bothered by a complicated switching 
operation and can obtain a desired copy very effectively.