Automatic document conveying device

An automatic document conveying device for use with an image processing machine having a transparent plate on which to place documents. The device includes an opening-closing frame and a document table. A conveyor roller is rotatably mounted in the opening-closing frame. A document delivery device is provided for delivering sheet-like documents from the document table. The document delivered from the document table is introduced into a required position on the transparent plate by the conveyor roller. The rotation of the conveyor roller in the introducing direction is stopped while the introduced document is still between the conveyor roller and the transparent plate. A guiding device which permits advance of the document from the document table to the transparent plate but hampers movement of the document from the transparent plate toward the document table and defects it upwardly, is provided between the document table and the conveyor roller. When the conveyor roller is rotated in the carrying direction, the document on the transparent plate is deflected upwardly by the guiding device and discharged through a discharge opening formed in the opening-closing frame.

FIELD OF THE INVENTION 
This invention relates to an automatic document conveying device for use 
with an image processing machine such as an electrostatic copying machine, 
and to various elements used in it. 
DESCRIPTION OF THE PRIOR ART 
To automatic handling of a document in a copying operation or the like, it 
has been the widespread practice to install an automatic document 
conveying device in an image processing machine such as an electrostatic 
copying machine. A typical example of the automatic document conveying 
device is disclosed in Japanese Laid-Open Patent Publication No. 
118551/1985. 
The above automatic conveying device includes an opening-closing frame and 
a document table. A transparent plate on which to place a document to be 
copied is disposed on the upper surface of the housing of the image 
processing machine. The opening-closing frame is mounted on the housing so 
as to be free to pivot around a pivot axis extending along one edge of the 
transparent plate as a center between a closed position at which it covers 
the transparent plate and an open position at which is exposes the 
transparent plate to view. The document table is mounted on the housing 
adjacent to the opening-closing frame. A document delivery means for 
delivering a plurality of sheet-like documents on the table one by one is 
annexed to the document table. A document conveying means is annexed to 
the opening-closing frame to convey the document delivered from the 
document table to a required position on the transparent plate, and after 
scanning of the document, transfer it to the upper surface of the 
opening-closing frame. The document conveying means comprises a conveyor 
belt mechanism extending along the transparent plate. 
In operation, the opening-closing frame of the automatic document conveying 
device is held at the closed position and sheet-like documents are placed 
in a stacked state on the document table. Then, the operation of the 
automatic document conveying device is started. One document is then 
delivered from the document table by the document delivery means, and 
conveyed to a required position on the transparent plate by the document 
conveying means. When the scanning of the conveyed document is over, the 
document is transferred to the upper surface of the opening-closing frame 
from the transparent plate by the document conveying means. The next 
document is then delivered from the document table by the document 
delivery means. 
The aforesaid conventional automatic document conveying device is 
relatively complex and expensive owing to the structure of the document 
conveying means including the conveyor belt mechanism. Accordingly, it is 
unsuitable for a relatively inexpensive low- to medium-grade image 
processing machines. 
SUMMARY OF THE INVENTION 
It is a primary object of this invention to provide a novel and improved 
automatic document conveying device which comprises a document conveying 
means of a simplified structure annexed to the opening-closing frame, is 
relatively low in the cost to build, and can therefore be applied 
conveniently to relatively inexpensive low- to medium-grade image 
processing machines. 
Another object of this invention is to improve an automatic document 
conveying device including a document conveying means of a simplified 
structure annexed to the opening-closing frame, in various respects in the 
structures of the constituent elements and in the control system for 
various actions of the device so as to permit precise and stable actions. 
Still another object of this invention is to provide various improved 
constituent elements which can, although not exclusively, be used 
conveniently in an automatic document conveying device including a 
document conveying means of a simplified structure annexed to the 
opening-closing frame. 
According to one aspect of the invention, a conveyor roller means is 
rotatably mounted on the opening-closing frame. When the opening-closing 
frame is held at the closed position, the conveying roller means is 
brought into intimate contact with the transparent plate disposed on the 
upper surface of the housing of the image processing machine. The leading 
edge of a document delivered from the document table by the document 
delivery means abuts with the intimately contacting site between the 
conveyor roller means out of action and the transparent plate, and when 
the leading edge of the document is inclined in the widthwise direction, 
the inclination is corrected. Then, the conveyor roller means is rotated 
in the conveying direction and the document is conveyed to a required 
position on the transparent plate. The rotation of the conveyor roller 
means in the conveying direction is stopped while the conveyed document is 
still nipped between the conveyor roller means and the transparent plate. 
Between the document table and the conveyor roller means is disposed a 
guiding means which permits advance of the document from the document 
table to the transparent plate, but hampers movement of the document from 
the transparent plate toward the document table and deflects it upwardly. 
The guiding means is comprised of a flexible thin piece projecting 
downwardly inclinedly toward the downstream side as viewed in the document 
delivering direction, and a plurality of cuts are formed at intervals in 
the thin piece in the widthwise direction. A discharge opening is formed 
in the opening-closing frame in relation to the conveyor roller means and 
the guiding means. When the scanning of the document conveyed onto the 
transparent plate is over, the conveyor roller means is rotated in the 
reverse direction, and the scanned document is conveyed onto the 
opening-closing frame through the discharge opening while being deflected 
upwardly by the guiding means. The rotation stop time of the conveyor 
roller means in the conveying direction is set according to the length of 
the document. The opening-closing frame is mounted so that its mounting 
height can be adjusted freely by a mounting mechanism having an adjusting 
screw. The opening or closing movement of the opening-closing frame is 
detected by a safety switch means whose detecting characteristics are 
maintained unchanged even when its mounting height is changed.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
With reference to the accompanying drawings, preferred embodiments of the 
automatic document conveying device of the invention will be described in 
detail. 
General Structure 
FIG. 1 shows an electrostatic copying machine shown generally at 2 and an 
automatic document conveying device shown generally at 4. The 
electrostatic copying machine 2 of a known type is provided with a nearly 
parallelepiped housing 6, and a transparent, usually rectangular, plate 8 
(FIGS. 2 and 3) on which to place documents with their surface to be 
copied down is disposed centrally on the upper surface of the housing 6. A 
paper cassette 10 holding a plurality of copying paper sheets is 
detachably mounted on one side of the housing 6, and a receiving tray 12 
is mounted on the other side of the housing 6. An operating panel 14 
(which will be described further later on) having a plurality of operating 
switches and displays, is provided in one side portion of the front end of 
the upper surface of the housing 6. Various constituent elements including 
a rotating drum having an electrostatographic layer on its surface are 
disposed within the housing 6, although they are not shown. A toner image 
is formed on the rotating drum by an image-forming step including document 
scanning and exposure involving optically scanning the document placed on 
the transparent plate 8 (FIGS. 2 and 3), and projecting a reflected image 
of the document onto the rotating drum. The toner image is transferred to 
a copying paper sheet fed from the paper cassette, and the copying paper 
sheet having the toner image transferred and fixed is then discharged onto 
the receiving tray 12. 
The illustrated automatic document conveying device 4 of the invention 
includes an opening-closing frame 16 and a stationary document table 18. 
The opening-closing frame 16 is mounted pivot between a closed position 
shown by a solid line in FIG. 1 and an open position shown partly in a 
simplified manner by a two-dot chain line in FIG. 1. Frame 16 is mounted 
pivotably about a pivot axis 19 extending along the rear edge of the 
transparent plate 8, or more specifically parallel to, and slightly 
rearwardly and upwardly of, the rear edge of the transparent plate 8 (the 
manner of mounting the opening-closing frame 16 will be described 
hereinafter). When the opening-closed frame 16 is held at the closing 
position, the transparent plate 8 is covered with the opening-closing 
frame 16, and when it is held at the open position, the transparent plate 
8 is exposed to view. When a document to be copied is placed on the 
transparent plate 8 by hand, it is necessary to operate the 
opening-closing frame 16 by hand. 
The document table 18 is mounted on the housing 6 adjacent to one side (the 
left side as viewed from the front) of the opening-closing frame 16. As 
will be described in detail hereafter, a document delivery means 20 (FIGS. 
2 and 3) is annexed to the document table 18, and a conveyor roller means 
22 (FIGS. 2 and 3) is annexed to the opening-closing frame 16. The 
document delivery means 20 delivers documents on the document table 18 one 
by one toward the transparent plate 8. The conveying roller means 22 
introduces the delivered document into a required position on the 
transparent plate 8 and carries the scanned document from the transparent 
plate 8 to the upper surface of the opening-closing frame 16. 
Document Table and Document Delivery Means 
With reference to FIGS. 2 and 3, the document table 18 may be made of a 
synthetic resin, and extends to the left from its downstream end which is 
in proximity to or in contact with the left side edge of the transparent 
plate 8. The document table 18 is mounted on the housing 6 by fixing its 
downstream portion to the wall of the upper surface of the housing 6 by 
screwing or otherwise. As clearly shown in FIG. 3, the document table 18 
has an inclined downstream portion 24 extending from the aforesaid 
downstream end in an upwardly inclined manner toward the left, a short 
oppositely inclined portion 26 inclined in the opposite direction, namely 
in a downwardly inclined manner toward the left, and a main portion 28 
extending from the oppositely inclined portion 26 in an upwardly inclined 
manner toward the left. A greater part of the main portion 28 projects to 
the left beyond the housing 6 of the electrostatic copying machine 2. As 
shown in FIG. 2, a pair of width restricting members 30 are mounted on the 
main portion 28 of the document table 18. The pair of width restricting 
members 30, which may be of a known type, are free to move toward and away 
from each other, and the distance between the two is set by hand at a 
length corresponding to the width of the document placed on the document 
table 18. As shown clearly in FIG. 2, a front upstanding plate 32 and a 
rear upstanding plate 34 are disposed on both sides of the downstream 
portion of the document table 18. Between the front upstanding plate 32 
and the rear upstanding plate 34 is disposed an upper guide plate 36 
extending above the downstream portion of the document table 18. 
A delivery roller mechanism 38 and a separating roller mechanism 40 are 
further provided between the front upstanding plate 32 and the rear 
upstanding plate 34. The delivery roller mechanism 38 and the separation 
roller mechanism 40 constitute the document delivery means 20. With 
reference to FIG. 4 in conjunction with FIGS. 2 and 3, an upper rotating 
shaft 42 and a lower rotating shaft 44 are rotatably mounted at a 
predetermined vertical interval between the front upstanding plate 32 and 
the rear upstanding plate 34. Three feed rollers 46 are fixed at suitable 
intervals in the axial direction to the upper rotating shaft 42. The feed 
rollers 46, which may be formed of a suitable material such as synthetic 
rubber, project downwardly through an opening formed in the upper guide 
plate 36. It will be seen by reference to FIG. 3 that the peripheral 
surfaces of the feed rollers are not completely circular, and a nearly 
crescent cut 48 is formed at a specific angular site on the feed rollers 
46. 
Four reverse-rotating rollers 50 are fixed at suitable intervals in the 
axial direction to the lower rotating shaft 44. The reverse-rotating 
rollers 50, which may be formed of a suitable material such as synthetic 
rubber, project upwardly through an opening formed in the inclined 
downstream portion 24 of the document table 18. It is seen from FIG. 4 
that the feed rollers 46 and the reverse-rotating rollers 50 are 
alternately arranged in the axial direction (i.e., the left-right 
direction in FIG. 4), and each of the feed rollers 46 is disposed between 
the adjacent reverse-rotating rollers 50. 
Base end portions of a pair of supporting arms 52 are pivotally mounted on 
the upper rotating shaft 42. The pair of supporting arms 52 extend to the 
left in FIG. 3, and a rotating shaft 54 is rotatably mounted across the 
free end portions of these supporting arms 52. Two delivery rollers 56 are 
fixed to the rotating shaft 54 at a suitable interval in the axial 
direction. The delivery rollers 56 may be formed of a suitable material 
such as synthetic rubber. 
Toothed pulleys 58 are also fixed to the upper rotating shaft 42 at 
positions adjacent to the base end portions of the pair of supporting arms 
52. Corresponding to the toothed pulleys 58, toothed pulleys 60 are fixed 
also to both end portions of the rotating shaft 54, and a timing belt 62 
is wrapped over each of the toothed pulleys 58 and each of the toothed 
pulleys 60. Accordingly, when the upper rotating shaft 42 is rotated 
counterclockwise in FIG. 3 in the manner to be described (during which the 
lower rotating shaft 44 is rotated counterclockwise in FIG. 3), the 
rotation of the upper rotating shaft 42 is transmitted to the rotating 
shaft 54 via the toothed pulleys 58, the timing belts 62 and the toothed 
pulleys 60, and the rotating shaft 54 is also rotated counterclockwise in 
FIG. 3. 
A cam shaft 64 is rotatably mounted between the front upstanding plate 32 
and the rear upstanding plate 34. A pair of cams 66 are fixed to the cam 
shaft 64 corresponding to the pair of supporting arms 52. The cams 66 each 
have an actuating protrusion 68. On the other hand, a flat restrained 
surface 70 is formed in the base end portions of the pair of supporting 
arms 52. When the cams 66 are held at the restraining positions shown in 
FIGS. 2 and 3, the actuating protrusions 68 of the cams 66 engage the 
restrained surfaces 70 of the supporting arms 52 to restrain the 
supporting arms 52 at the elevated positions shown in FIGS. 2 and 3 when 
the supporting arms 52 are restrained at the elevated positions, the 
delivery rollers 56 are lifted upwardly from the upper surface of the 
document table 18 by a predetermined distance. When the cam shaft 64 and 
the cams 66 fixed to it are rotated counterclockwise in FIG. 3 in the 
manner to be described, the actuating protrusions 68 of the cams 66 move 
away from the restrained surfaces 70 of the supporting arms 52. As a 
result, the pair of supporting arms 52 are pivoted counterclockwise in 
FIG. 3 around the upper rotating shaft 42 as a center owing to their own 
weight and the weight of the rotating shaft 54, etc. mounted across their 
free ends. Thus, the rotating shaft 54 and the delivery rollers 56 mounted 
on it are lowered and come into contact with the document placed on the 
document table 18 (see FIG. 14-B also). When the cam shaft 64 and the cams 
66 fixed to it are rotated through one turn and returned to the 
restraining positions shown in FIGS. 2 and 3, the actuating protrusions 68 
of the cams 66 act on the restrained surfaces 70 of the supporting arms 52 
to return the supporting arms 52 to, and restrain them at, the elevated 
positions described above. 
As clearly shown in FIG. 3, a set document detector 72 and a delivered 
document detector 74 are disposed in relation to the downstream portion 
(the right end portion in FIG. 3) of the document table 18. The set 
document detector 72 is comprised of a switch having a detecting arm 73 
which projects upwardly through an opening formed centrally in the width 
direction in the downstream end portion of the main portion 28 of the 
document table 18. The delivered document detector 74 is also comprised of 
a switch having a detecting arm 75 which projects upwardly through an 
opening formed centrally in the width direction in the inclined downstream 
portion 24 of the document table 18. 
A document restraining member 76 is further disposed in the illustrated 
document table 18. As shown clearly in FIG. 3, the document restraining 
member 76 is mounted pivotally about a pin 78 extending in the width 
direction (the direction perpendicular to the sheet surface in FIG. 3). A 
tension spring 80 and an electromagnetic solenoid 82 are also provided in 
the document restraining member 76 disposed centrally in the width 
direction. The tension spring 80 elastically biases the document 
restraining member 76 counterclockwise in FIG. 3, and elastically 
maintains it at an operative position shown in FIG. 3. When the document 
restraining member 76 is held at the operative position, its free end 
portion projects upwardly through an opening formed in the downstream end 
of the oppositely inclined portion 26 of the document table 18. When the 
electromagnetic solenoid 82 is energized, the document restraining member 
76 is pivoted clockwise in FIG. 3 to a non-operative position against the 
elastic biasing action of the tension spring 80, and its free end portion 
is moved below the upper surface of the document table 18 (see FIG. 14-B 
also). 
As clearly shown in FIGS. 1 and 3, a nearly box-like cover 84 having an 
open bottom is disposed in the downstream portion of the document table 
18, and the delivery roller mechanism 38 and the separation roller 
mechanism 40 are covered with the cover 84 (a driving system to be 
described for the delivery roller mechanism 38 and the separation roller 
mechanism 40 are also covered with the cover 84). 
Opening-Closing Frame 
With reference to FIGS. 1 and 3, the opening-closing frame 16, which can be 
formed of a suitable synthetic resin, is generally box-like with an open 
bottom. As clearly shown in FIG. 1, a main portion 86 of the 
opening-closing frame 16 is depressed, and its upper surface is slightly 
lower than the upper surfaces of a rear edge portion 88, a left side edge 
portion 90 and a right side edge portion 92. As shown in FIG. 3, an 
elongate discharge opening 96 extending in the width direction (the 
direction perpendicular to the sheet surface in FIG. 3) is formed in a 
wall 94 extending downwardly from the right side edge of the upper surface 
of the left side edge portion 90 toward the upper surface of the main 
portion 86. The width of the discharge opening 96 corresponds to the width 
of the document table 18. As will be described in detail hereinafter, the 
document is discharged onto the upper surface of the main portion 86 
through the discharge opening 96, and hence, the upper surface of the main 
portion 86 constitutes a document receiving surface. 
Conveniently, a plurality of slender protrusions 98 extending in the 
document conveying direction (the left-right direction in FIG. 3) are 
formed at suitable intervals in the width direction on the upper surface 
of the main portion 86. As shown in FIG. 1, a depression 100 which can be 
held by fingers when opening or closing the opening-closing frame 16 is 
disposed in the front surface of the opening-closing frame 16. 
Furthermore, a pair of abutting protrusions 102 spaced from each other in 
the left-right direction in FIG. 3 extend from the lower end of the front 
surface of the opening-closing frame 16, as shown in FIG. 3. When the 
opening-closed frame 16 is held at the closing position shown in FIG. 3, 
the abutting protrusions 102 abut with the upper surface of the housing 6 
of the electrostatic copying machine 2, whereby the closed position of the 
opening-closing frame 16 is regulated as is required. 
A number of suspending columns 104 are formed integrally with the under 
surface of the main portion 86 of the opening closing frame 16, as shown 
in FIG. 3, and a plate member 106, which may be rectangular, is fixed to 
the lower ends of the suspending columns 104. When the opening-closing 
frame 16 is held at the closed position, the plate member 106 is 
positioned opposite to the transparent plate 8. In the left end portion of 
the plate member 106, a cut extending to the right by a predetermined 
length from the left end of the plate member 106 is formed corresponding 
to a roller, to be described later, in the conveyor roller means 22. The 
plate member 106 may be formed of a suitable synthetic resin, and its 
under surface is white in color. As will be described in detail 
hereinafter, the sheet-like document to be copied is introduced between 
the transparent plate 8 and the plate member 106 to introduce the document 
stably without being hampered by the plate member 106, it is convenient to 
provide a clearance of about 1.0 mm between the transparent plate 8 and 
the plate member 106 when the opening-closing frame 16 is at the closed 
position. The left end portion of the plate member 106 may be inclined 
slightly upwardly to the left. 
As already stated with reference to FIG. 1, the opening-closing frame 16 
must be mounted pivotally around the pivot axis 19. With reference to FIG. 
5, a mounting mechanism shown generally at 108 may be utilized to mount 
the opening-closing frame 16. The illustrated mounting mechanism 108 
includes a mounting member 110 and a pivot member 114 pivotally linked to 
the mounting member 110 via a pin 112. An insertion rod 116 extends 
downwardly from the under surface of the mounting member 110. The mounting 
mechanism 108, comprised of the mounting member 110 having the insertion 
rod 116 formed therein and the pivot member 114 linked pivotally to the 
mounting member 110 via the pin 112, is known to those skilled in the art 
and is generally available commercially. In the mounting mechanism 108 
improved in accordance with this invention, an adjusting screw 118 is 
secured to the under surface of the mounting member 110 so that the degree 
of its screwing can be adjusted. To mount the opening-closing frame 16 by 
utilizing this mounting mechanism 108, the pivot member 114 of the 
mounting mechanism 108 is fixed to the inside surface of the rear edge 
portion 88 of the opening-closing frame 16 by a suitable method such as 
screwing. On the other hand, an insertion hole 120, extending downwardly 
from the upper surface of the housing 6, is formed in the housing 6. The 
insertion rod 116 extending from the mounting member 110 is inserted into 
the insertion hole 120, and the head of the adjusting screw 118 is caused 
to abut the upper surface of the housing 6. As a result, the 
opening-closing frame 16 is mounted on the housing 6 so that it is free to 
pivot about the pin 112 of the mounting mechanism 108. Hence, the central 
axis of the pin 112 constitutes the aforesaid pivot axis 19. 
As already stated with reference to FIG. 3, it is important that in the 
illustrated embodiment, a clearance of about 1.0 mm exists between the 
transparent plate 8 and the plate member 106 when the opening-closing 
frame 16 is held at the closed position. To set the clearance precisely at 
the required value, it is important to adjust the thickness of the 
abutting protrusions 102, which are to abut with the upper surface of the 
housing 6 at the front edge of the opening-closing frame 16, precisely to 
a predetermined value and to adjust the mounting height at the rear edge 
of the opening-closing frame 16 (this mounting height can be shown, for 
example, by the distance h between the upper surface of the housing 6 and 
the pivot axis 19) precisely to a predetermined value. In the mounting 
mechanism 108 improved by the present invention, the mounting height h can 
be finely adjusted by properly controlling the degree of screwing of the 
adjusting screw 118 with respect to the mounting member 110. Specifically, 
the mounting height h can be increased when the degree of screwing is 
decreased and the amount of protrusion of the adjusting screw 118 from the 
under surface of the mounting member 110 is thereby increased. Conversely, 
when the degree of screwing is increased and the amount of protrusion of 
the adjusting screw 118 is thereby decreased, the mounting height h is 
decreased. To adjust the mounting height h in this manner, it is important 
that the insertion rod 114 extending from the mounting member 110 should 
be inserted into the insertion hole 120 formed in the housing 6 so as to 
be free to ascend and descend. To prevent the degree of screwing of the 
adjusting screw 118 from changing owing to vibration or otherwise, a check 
nut or the like may be combined with the adjusting screw 118 if required. 
Only one such mounting mechanism 108 may be used to mount the 
opening-closing frame 16, but desirably, two or more mounting mechanisms 
108 are used at suitable intervals in the direction of the pivot axis 19. 
With reference to FIG. 5, a safety switch means 122 is disposed in the 
illustrated embodiment in order to detect the opening and closing of the 
opening-closing frame 16. The safety switch means 122 is comprised of a 
combination of a switch element 124 and an actuating piece 126. The switch 
element 124 may be composed of a microswitch having a detecting arm 128, 
and is fixed to the inside surface of the rear edge portion 88 of the 
opening-closing frame 16. The actuating piece 126 is fixed to the side 
surface of the mounting member 110 in the mounting mechanism 108. When the 
opening-closed frame 16 is at the closing position shown by the solid 
line, the free end of the actuating piece 126 acts on the detecting arm 
128 of the switch element 124 to close the switch element 124. When the 
opening-closing frame 16 is opened to a specific angular position shown by 
the two-dot chain line, the free end of the actuating piece 126 moves away 
from the detecting arm 128 to open the switch element 124. When the switch 
element 124 is opened, the actuation of the document delivery means 20 and 
the conveyor roller means 22 fails. In the above-described safety switch 
means 122, the actuation piece 126 is fixed to the mounting member 110 of 
the mounting mechanism 108. Hence, when the mounting member 110 is 
elevated or lowered by varying the degree of screwing of the adjusting 
screw 118, the actuating piece 126 is accordingly elevated or lowered. 
Thus, even when the mounting height of the opening-closing frame 16 is 
varied, the positional relationship between the switch element 124 and the 
actuating piece 126 remains the same, and the detecting characteristics of 
the safety switch means 122 (namely, the angular position of the 
opening-closing frame 16 when the switch element 124 is open) remain the 
same. It will be easily understood that if the actuating piece 126 is 
fixed to the housing 6 instead of fixing it to the mounting member 110 of 
the mounting mechanism 108, changing of the mounting height of the 
opening-closing frame 16 by varying the degree of screwing of the 
adjusting screw 118 results in a change in the relative positions of the 
switch element 124 and the actuating piece 126, and the detecting 
characteristics of the safety switch means 122 change. On the other hand, 
the detecting characteristics of the safety switch means 122 can be 
maintained the same even when as required, the switch element 124 is fixed 
to the pivot member 114 of the mounting mechanism 108 instead of the 
opening-closing frame 16, or the actuating piece 126 is fixed to the 
opening-closing frame 16 or the pivot member 114 and the switch element 
124 is fixed to the mounting member 110. 
FIG. 6 shows a modified example of the safety switch means 122. In this 
modified example, a depression 130 is formed in the upper surface of the 
housing 6, and a compression spring 132 together with the actuating piece 
126 is received in the depression 130. The compression spring 132 
elastically biases the actuating piece 126 upwardly and causes one end of 
the actuating piece 126 to abut the under surface of the mounting member 
110. In this modified example, too, when the mounting member 110 is 
elevated or lowered by changing the degree of screwing of the adjusting 
screw 118, the actuating piece 126 is accordingly elevated or lowered. 
Hence, even when the mounting height of the opening-closing frame 16 
changed, the relation between the switch element 124 and the actuating 
piece 126 is maintained the same, and the detecting characteristics of the 
safety switch means 122 are maintained the same. 
The mounting mechanism 108 and the safety switch means 122 described above 
with reference to FIGS. 5 and 6 can be applied especially conveniently to 
the opening-closing frame 16 of the automatic document conveying device 4. 
They can also be applied to an ordinary opening-closing frame which has no 
document conveying function but is useful for covering a document placed 
on the transparent plate. 
Conveyor Roller Means 
The conveyor roller means 22 annexed to the opening-closing frame 16, as 
clearly shown in FIG. 3, is disposed within the left side edge portion 90 
of the opening-closing frame 16. With reference to FIG. 7 in conjunction 
with FIGS. 2 and 3, a front and a rear supporting wall 134 and 136 are 
formed integrally in the left side edge portion 90 of the opening-closing 
frame 16. A rotating shaft 138 is rotatably mounted between the front and 
rear supporting walls 134 and 136. The rotating shaft 138 extends 
substantially perpendicularly to the pivot axis 19 of the opening-closing 
frame 16, and when the opening-closing frame 16 is held at the closed 
position, extends substantially horizontally on one side portion of the 
transparent plate 8. 
As shown in FIGS. 2 and 7, a central roller 140, disposed centrally in the 
axial direction of the rotating shaft 138, and side rollers 142 and 144, 
disposed on both sides of the central roller 140, are mounted on the 
rotating shaft 138. The central roller 140 has a relatively broad width, 
and is comprised of a base portion 146 fixed to the rotating shaft 138 and 
a surface layer 148 fixed to the peripheral surface of the base portion 
146. The base portion 146 may be formed of a suitable synthetic resin. The 
surface layer 148 is preferably formed of a flexible material such as a 
formed synthetic resin. One preferred example of the formed synthetic 
resin to make the surface layer 148 is formed polyurethane sold under the 
tradename "EMO" by Inoue MTP Co., Ltd. 
Base ends of cantilever supporting members 150 and 152 extending axially 
are fixed to both side surfaces of the base portion 146 of the central 
roller 140. The cantilever supporting members 150 and 152 may be of a 
cylindrical form extending around, and concentric with, the rotating shaft 
138, and may be formed of a suitable synthetic resin. The side rollers 142 
and 144 are not directly fixed to the rotating shaft, but are fixed to the 
free ends of the cantilever supporting members 150 and 152 and therefore 
are supported by the cantilever supporting members 150 and 152. The side 
rollers 142 and 144 are comprised respectively of cylindrical base 
portions 154 and 156, fixed to the free ends of the cantilever supporting 
members 150 and 152, and surface layers 158 and 160. The base portions 154 
and 156 may be formed of a suitable synthetic resin, and have an inside 
diameter much larger than the outside diameter of the rotating shaft 138 
so that a sufficient gap exists between them. The surface layers 158 and 
160 of the side rollers 142 and 144 are preferably formed of a flexible 
material such as a formed synthetic resin, as is the surface layer 148 of 
the central roller 140. It is important that the outside diameter d.sub.1 
of the central roller 140 should be set such that when the opening-closed 
frame 16 is at the closing position, the peripheral surface of the central 
roller 140 is brought into contact with the upper surface of the 
transparent plate 8. Let the distance between the axis of the rotating 
shaft 138 and the upper surface of the transparent plate 8 when the 
opening-closing frame 16 is held at the closed position be l, the outside 
diameter d.sub.1 of the central roller 140 can be set so that it satisfies 
the equation d.sub.1 /2=l+.alpha. in which .alpha. is about 0.5 to 1.0 mm. 
On the other hand, the outside diameter d.sub.2 of the side rollers 142 
and 144 is conveniently larger than the outside diameter d.sub.1 of the 
central roller 140 by about 1.0 to 2.0 mm. When the opening-closing frame 
16 is held at the closed position, the side rollers 142 and 144 are 
brought into intimate contact with the upper surface of the transparent 
plate 8 with elastic deformation of their surface layers 158 and 160 and 
the elastic flexing of the cantilever supporting members 150 and 152. 
As shown in FIGS. 3 and 8, a plurality of guiding ribs 162 are provided at 
suitable intervals in the width direction (the direction perpendicular to 
the sheet surface in FIG. 3) in the left side edge portion 90 of the 
opening-closing frame 16 in relation to the conveyor roller means 22. The 
lower edges of the guiding ribs 162 extend to the left and right nearly 
along the conveyor roller means 22. A follower roller 166 is rotatably 
mounted on the guiding ribs 162 by a pin 164. The follower roller 166 
projects downwardly beyond the lower edges of the guiding ribs 162, and 
makes contact with the central roller 140 in the conveyor roller means 22. 
Guiding Means 
With reference to FIGS. 3 and 8, a guiding means 168, which permits the 
advancing of the document to the transparent plate 8 from the document 
table 18 but hampers the movement of the document toward the document 
table 18 from the transparent plate 8 and deflects it upwardly, is 
disposed between the conveyor roller means 22 and the delivery end (i.e., 
the downstream end) of the document table 18 positioned adjacent to it. 
The guiding means 168 is comprised of a flexible thin piece 172 secured to 
the inside surface of the left wall of the opening-closing frame 16 via a 
slender supporting member 170. As clearly depicted in FIG. 8, the 
supporting member 170 extends in the width direction (the direction 
perpendicular to the sheet surface in FIG. 8) and is fixed to the inside 
surface of the left side wall of the opening-closing frame 16. The 
supporting member 170 may be formed of a suitable plate material such as a 
copper plate. Its lower end portion is inclined downwardly to the right 
and projects from the inside surface of the left side wall of the 
opening-closing frame 16. The thin piece 172 constituting the guiding 
means 168 is bonded at its upper end portion to the lower end portion of 
the supporting member 170 and is inclined downwardly to the right (and 
therefore inclined downwardly in the downstream direction as viewed in the 
direction of delivering from the document table 18). An inclined surface 
174 inclined downwardly to the left is formed in the left side end portion 
of the transparent plate 8, and the lower end of the thin piece 172 is 
kept in contact with the inclined surface 174 of the transparent plate 8. 
As will be described in detail hereinafter, when the document is delivered 
from the document table 18 toward the surface of the transparent plate 8, 
it is important that the leading edge of the document should act on the 
thin piece 172, and the thin piece 172 should bend upwardly. Accordingly, 
it is important that the thin piece 172 itself should bend relatively 
easily. The thin piece 172 may be conveniently formed from a suitable 
synthetic resin film, for example, a polyester film having a thickness of 
about 0.075 mm. If desired, the thin piece 172 may be formed of a suitable 
metallic foil. When the thin piece 172 is formed of a conductive metal 
foil, the thin piece 172 can be grounded and caused to function also as a 
charge eliminating means for removing an undesirable static charge from 
the document. 
As shown clearly in FIG. 9, a plurality of recesses 176 are preferably 
formed in the thin piece 172 at suitable intervals in the width direction. 
The width positions of the recesses 176 are preferably not in alignment 
with both side edges of the document of a specified size delivered from 
the document table 18 but deviate in the width direction with respect to 
the side edges. In the illustrated embodiment, the document table 18 is 
designed to deliver documents having width dimensions defined as B6, B5,A5 
and A4 by JIS (Japanese Industrial Standards), and as shown in FIG. 9, the 
recesses 176 formed in the thin piece 172 deviate in the width direction 
with respect to the two side edges of documents having these various 
sizes. The recesses 176 facilitate the required flexing of the thin piece 
172 by the action of the document delivered from the document table 18. It 
should also be noted that when a relatively narrow document having a size 
of, for example, B6 or A5 is delivered from the document table 18, its 
leading edge acts only on the central portion of the thin piece 172, and 
when the recesses 176 are absent, the thin piece 172 tends to be bent 
between its central portion and each side portion. If this bending occurs 
repeatedly and becomes incessant, a document delivered to the left in FIG. 
8 from the transparent plate 10 is likely to abut the lower end of the 
thin piece 172 and jam up without being deflected upwardly along the thin 
piece 172. In contrast, in the presence of the recesses 176, both side 
portions of the thin piece 172 which exist outwardly of the outermost 
recess 176 continue to be maintained in the initial state without bending 
during delivering of such a narrow document from the document table 18, as 
can be seen from FIG. 9. Accordingly, the aforesaid bending can be 
avoided. On the other hand, when the recesses 176 are formed in alignment 
with both side edges of the document, both corner portions of the document 
enter the recesses 176 when the document is delivered to the left in FIG. 
8 from the transparent plate 8 and raised along the thin piece 172. This 
is likely to result in document jamming. 
FIG. 10 shows a modified example of the guiding means. In this modified 
example, the inclined surface 174 is formed in an additional portion 
annexed integrally to the downstream end of the document table 18 instead 
of forming the inclined surface 174 in the transparent plate 8 itself. The 
lower end of the thin piece 172 is kept in contact with this inclined 
surface 174. 
FIG. 11 shows another modified example of the guiding means. In this 
modified example, the upper end portion of the thin piece 172 is fixed to 
the outside surface of the cover 84 disposed in the downstream portion of 
the document table 18. The thin piece 172 has an extension which extends 
further upwardly from its lower end kept in contact with the inclined 
surface 174. 
Driving Control Means 
With reference to FIGS. 12 and 13 in conjunction with FIGS. 2 and 4, a 
reversible electric motor 178 is disposed rearwardly of the rear 
upstanding plate 34 provided at the back of the downstream portion of the 
document table 18. The reversible electric motor 178 constitutes a common 
driving source for the document delivery means 20 and the conveyor roller 
means 22. A gear 182 is fixed to the output shaft 180 of the motor 178. 
A linking means between the reversible motor 178 and the document delivery 
means 20 will be described. As shown in FIGS. 4 and 12, the rear end 
portion of the lower rotating shaft 44 to which the reverse-rotating 
roller 50 is fixed projects rearwardly beyond the rear upstanding plate 
34, and a gear 186 is mounted on this rear end portion of the lower 
rotating shaft 44 via a one-way clutch mechanism 184. A short rod 188 
projecting rearwardly is implanted in the rear upstanding plate 34, and an 
idler gear 190 is rotatably mounted on the short rod 188. The idler gear 
190 drivingly connects the gear 182 to the gear 186. When the motor 178 is 
rotated in a normal direction shown by an arrow 192 and the gear 186 
rotates in the direction of arrow 192, the one-way clutch mechanism 184 
transmits the rotation of the gear 186 to the lower rotating shaft 44. On 
the other hand, when the motor 178 is rotated in a reverse direction shown 
by an arrow 194 and the gear 186 is rotated in the direction of arrow 194, 
the lower rotating shaft 44 is not rotated. As shown in FIGS. 3 and 13, 
the front end portion of the lower rotating shaft 44 projects forwardly 
beyond the front upstanding plate 32, and a gear 196 is fixed to this 
front end portion of the lower rotating shaft 44. The front end portion of 
the upper rotating shaft 42, to which the feed roller 46 is fixed, also 
projects forwardly beyond the front upstanding plate 32, and a gear 200 is 
mounted on this front end portion of the upper rotating shaft 42 via a 
solenoid-controlled spring clutch mechanism 198. The spring clutch 
mechanism 198 is of the type in which one engagement protrusion 202 is 
formed on the outer circumferential surface of its boss. When a solenoid 
204 is instantaneously energized and a control claw 206 is instantaneously 
released from the engagement protrusion 202, the clutch mechanism 198 
connects the gear 200 to the upper rotating shaft 42 through one rotation, 
namely until the control claw 206 is returned to the original position by 
the deenergization of the solenoid 204 and is again brought into 
engagement with the engagement protrusion 202. A forwardly projecting 
short rod 208 is implanted in the front upstanding plate 32, and an idler 
gear 210 for drivingly connecting the gear 196 to the gear 200 is 
rotatably mounted on the short rod 208. Accordingly, when the motor 178 is 
rotated in a normal direction, the gear 200 is rotated together with the 
lower rotating shaft 44 to which the reverse-rotating roller 50 is fixed. 
To the front end portion of the upper rotating shaft 42 is further fixed a 
gear 212 separate from the clutch mechanism 198 and the gear 200. The 
front end portion of the cam shaft 64 having the cam 66 fixed thereto also 
projects forwardly beyond the front upstanding plate 32, and a gear 214 is 
fixed to this front end portion of the cam shaft 64. A forwardly 
projecting short rod 216 is also implanted in the front upstanding plate 
32, and an idler gear 218 for drivingly connecting the gear 212 to the 
gear 214 is rotatably mounted on the short rod 216. 
With the above structure, when the motor 178 is rotated in the direction of 
arrow 192, the lower rotating shaft 44 having the reverse-rotating roller 
50 fixed thereto is rotated in the direction of arrow 192 
(counterclockwise in FIG. 3). In this state, when the solenoid 204 is 
instantaneously energized, the upper rotating shaft 42 having the feed 
roller 46 fixed thereto is rotated through one turn in the direction of 
arrow 192 (counterclockwise in FIG. 3). The rotating of the upper rotating 
shaft 42 is transmitted to the rotating shaft 54 via the timing belt 62, 
and therefore, the rotating shaft 54 to which the delivery roller 56 is 
fixed is also rotated through one turn in the direction of arrow 192 
(counterclockwise in FIG. 3). At the same time, the cam shaft 64 to which 
the cams 66 are fixed is also rotated through one turn in the direction of 
arrow 192 (counterclockwise in FIG. 3). Hence, the delivery roller 56 is 
lowered from the elevated position shown in FIGS. 2 and 3, and again 
returned to the elevated position. 
Now, a linking means between the reversible electric motor 178 and the 
conveyor roller means 22 will be described. As FIGS. 4 and 12 show, the 
rear end portion of the upper rotating shaft 42 to which the feed roller 
46 is fixed projects rearwardly beyond the rear upstanding plate 32. An 
idler gear 220 is rotatably mounted on this rear end portion of the upper 
rotating shaft 42, and a supporting plate 222 is pivotally mounted also on 
it. The idler gear 220 is kept in engagement with the idler gear 190. On 
the other hand, as schematically shown in FIG. 12, the supporting plate 
222 is elastically biased clockwise in FIG. 12 by a tension spring 224 and 
is elastically held at the illustrated position with which a stationary 
abutting piece 226 is to abut. Two short rods 228 and 230 are implanted in 
the supporting plate 222, and idler gears 232 and 234 are rotatably 
mounted on the short rods 228 and 230. The idler gear 232 is kept in 
engagement with the idler gears 220 and 234. With reference to FIGS. 2 and 
7 together with FIGS. 4 and 12, a rearwardly projecting short rod 236 is 
implanted in the rear supporting wall 136 formed in the opening-closing 
frame 16, and an idler gear 238 is rotatably mounted on the short rod 236. 
When the opening-closing frame 16 is held at the closed position, the 
idler gear 238 is brought into engagement with the idler gear 234. When at 
the time of this engagement, the teeth of the two gears 234 and 238 
contact each other, the supporting plate 222 is slightly pivoted 
counterclockwise in FIG. 12. When the two gears 234 and 238 are brought 
into engagement in the required manner, the supporting plate 222 is 
returned to the original position by the elastic biasing action of the 
tension spring 224. 
The rear end portion of the rotating shaft 138 of the conveyor roller means 
22 projects rearwardly beyond the rear supporting wall 136, and a gear 244 
is mounted on this rear end portion of the rotating shaft 138 via a 
one-way clutch mechanism 240 and a solenoid-controlled spring clutch 
mechanism 242. This gear 244 is kept in engagement with the idler gear 
238. When the motor 178 is reversely rotated in the direction of arrow 194 
and the gear 244 is rotated in the direction of arrow 194, the one-way 
clutch mechanism 240 transmits the rotation of the gear 244 to the 
rotating shaft 138 and rotates the shaft 138 in the direction shown by 
arrow 194 (clockwise in FIG. 3). When the motor 178 is rotated normally in 
the direction of arrow 192 and the gear 244 is rotated in the direction of 
arrow 192, the rotation of the gear 244 is not transmitted to the rotating 
shaft 138 via the one-way clutch mechanism 240. 
The above spring clutch mechanism 242 is of the type in which a number of 
engagement protrusions are formed on the outer circumferential surface of 
its boss. When the solenoid 246 is energized to detach a control claw 248 
from the engagement protrusions during the normal rotation of the motor 
178 in the direction of arrow 192 and the rotation of the gear 244 in the 
direction of arrow 192, the spring clutch mechanism 242 transmits the 
rotation of the gear 244 to the rotating shaft 138 to rotate the rotating 
shaft 138 in the direction of arrow 192. On the other hand, when the motor 
178 is rotated reversely in the direction of arrow 194 and the gear 244 is 
also rotated in the direction of arrow 194, the boss having the engagement 
protrusions formed thereon idly rotates in the non-restrained direction. 
Thus when the solenoid 246 is deenergized and the control claw 248 is held 
at the operative position, noises occur by the action of the engagement 
protrusions upon the control claw 248. Accordingly, when the motor 178 is 
rotated reversely in the direction of arrow 194, the gear 244 is rotated 
in the direction of arrow 194, and the rotation of the gear 244 is 
transmitted to the rotating shaft 138 via the one-way clutch mechanism 
240, it is desirable to avoid occurrence of the noises by energizing the 
solenoid 246, irrespective of the transmission of the rotation, and 
detaching the control claw 248 from the engagement protrusions. 
Thus, when the motor 178 is rotated in the direction of arrow 192 and the 
solenoid 246 is energized, the rotating shaft 138 of the conveyor roller 
means 22 is rotated in the direction of arrow 192 (counterclockwise in 
FIG. 3). On the other hand, when the motor 178 is rotated reversely in the 
direction of arrow 194, the rotating shaft 138 of the conveyor roller 
means 22 is rotated in the direction of arrow 194 (clockwise in FIG. 3). 
As shown in FIGS. 2, 4 and 7, the rotating shaft 138 of the conveyor roller 
means 22 has annexed thereto a detecting means 250 for detecting the 
amount of its rotation. The detecting means 250 may be of a known form and 
is comprised of a rotating plate 252 fixed to the rear end portion of the 
rotating shaft 138, and a photoelectric rotation detector 254 disposed in 
relation to the rotating plate 252. A number of holes 256 are formed in 
the rotating plate 252 at equiangular intervals. The detector 254 has a 
light emitting element 258 disposed on one side of the rotating plate 252 
and a light receiving element 260 disposed on the other side of the 
rotating plate 252. Every time the rotating plate 252 rotates in the 
direction of arrow 192 or 194 and one hole 256 passes between the light 
emitting element 258 and the light receiving element 260, the light 
receiving element 260 receives light from the light emitting element 258 
and produces a pulse. 
Operating Procedure 
Now, with reference to FIGS. 14-A to 14-F, 15 and 16, the operating 
procedure of the automatic document conveying device 4 will be described. 
When a plurality of sheet-like documents are to be successively copied by 
using the automatic document conveying device 4, as shown in FIG. 14-A, 
the sheet-like documents 262 are stacked on the document table 18 with 
their printed surfaces down, and the forward edges of the documents 262 
are brought into contact with, or near to, the oppositely inclined portion 
26 of the document table 18. The document restraining member 76 held at 
the operative position hampers the forward movement of the documents 262 
beyond the oppositely inclined portion 26. When the documents 262 are 
placed in the required manner on the document table 18, the set document 
detector 72 is actuated. As a result, a controller 264 (FIG. 15) provided 
in the automatic document conveying device 4, feeds a signal showing the 
presence of the documents 262 on the document table 18 to a controller 266 
provided in the electrostatic copying machine 2. The controllers 264 and 
266 may each be constructed of a microprocessor. When the operator then 
depresses a copy start switch button PS (FIG. 1) on the operating panel 14 
of the electrostatic copying machine 2, a signal indicating start of 
document delivery is fed to the controller 264 from the controller 266. 
When this signal is produced, the controller 264 starts the reverse 
rotation of the reversible electric motor 178 (at the same time, the 
solenoid 246 of the clutch mechanism 242 is energized to avoid occurrence 
of the noises) prior to document delivery. Thus, the conveyor roller 22 
preliminarily begins to rotate clockwise in FIG. 14-A. When a 
predetermined time t.sub.0-1 defined by a timer T.sub.0-1 has elapsed, the 
motor 178 is deenergized and stops its reverse rotation (the solenoid 246 
of the spring clutch mechanism 242 is also deenergized). For example, when 
the document manually placed on a transparent plate 8 remains on it 
without being removed, it is delivered to the left in FIG. 14-A by the 
action of the conveyor roller means 22 while the roller means 22 is 
preliminarily rotated. The document is deflected upwardly by the guiding 
means 168, and discharged onto the document receiving surface (namely, the 
upper surface of the main portion 86 of the opening-closing frame 16) 
through the discharge opening 96 by the action of the conveyor roller 
means 22 and the follower roller 166 cooperating with it. The 
predetermined time t.sub.0-1 may be set at a time interval required for 
discharging a document of the largest size that can be placed on the 
transparent plate 8. If desired, it is possible to provide a detector (not 
shown) for detecting the delivered document above the guiding means 168 
and to stop the preliminary rotation of the conveyor roller means 22 when 
the detector does not detect the document (and therefore, no document 
remains on the transparent plate 8) after a time period shorter than the 
above predetermined time t.sub.0-1 (corresponding to the time required for 
the remaining document which has begun to be delivered by the action of 
the conveyor roller 22 to reach the detector) has elapsed from the time of 
starting the preliminary rotation of the conveyor roller 22. 
When the motor 178 is deenergized and some period of time t.sub.0-2 defined 
by a timer T.sub.0-2 has elapsed from the time when the preliminary 
rotation of the conveyor roller 22 is stopped, the controller 264 start 
normal rotation of the motor 178. Then, after a predetermined period of 
time t.sub.1, set by a timer T1 built in the controller 264 (for example, 
150 ms), has passed, energization of solenoid 82 is started. As a result, 
the document restraining member 76 is moved backward to its non-operative 
position shown in FIG. 14-B from its operative position shown in FIG. 
14-A. Furthermore, after a predetermined time t.sub.2, set by a timer T2 
built in the controller 264 (for example, 300 ms), has passed from the 
starting of the normal rotation of the motor 178, the solenoid 204 of the 
spring clutch mechanism 198 is energized instantaneously for a 
predetermined time t.sub.3 set by a timer T3 built in the controller 264. 
The predetermined time T.sub.3 may be about 150 ms. When the solenoid 204 
is instantaneously energized, the cam shaft 64 to which the cams 66 are 
fixed is rotated counterclockwise in FIGS. 14-A and 14-B to lower the 
delivery roller 56 from its elevated position shown in FIG. 14-A to its 
lowered position shown in FIG. 14-B and bring roller 56 into contact with 
the uppermost document 262 of the stack of documents 262. At the same 
time, the delivery roller 56 is rotated counterclockwise in FIG. 14-B and 
the feed roller 46 and the reverse rotating roller 50 are rotated 
counterclockwise in FIG. 14-B. As a result, the uppermost document 262 on 
the document table 18 is delivered downstream (to the right in FIG. 14-B), 
and the delivered document 262 is further fed downstream by the feed 
roller 46. The reverse-rotating roller 50 prevents two or more documents 
262 from being fed simultaneously. The delivered document 262 actuates the 
delivered document detector 74, and then its leading edge abuts with the 
intimately contacting site between the transparent plate 8 and the rollers 
140, 142 and 144 of the conveyor roller means 22 which is still in a 
non-operative state (out of operation). When the leading edge of the 
document 262 delivered from the document table 18 is inclined as viewed in 
the width direction, its inclination is remedied by the above abutment. 
Since as stated above the solenoid 204 is energized only instantaneously, 
the delivery roller 56 and the feed roller 46 stop after one rotation. In 
the meantime, the reverse-rotating roller 50 continues to rotate. The cam 
shaft 64 stops after one rotation. Hence, as shown in FIG. 14-C, the 
delivery roller 56 is again returned to the elevated position. The amount 
of feeding of the document 262 by one rotation of the feed roller 46 is 
set at a value slightly larger than the amount of feeding required to 
advance the leading edge of the document 262 to the aforesaid intimately 
contacting site between the transparent plate 8 and the rollers 140, 142 
and 144. Accordingly, the inclination of the document 262 can be exactly 
corrected. At this point, the trailing end of the document 262 still is 
between the feed roller 46 and the reverse-rotating roller 50. The feed 
roller 46 is at a stop at such an angular position that the cut 48 formed 
on its outer circumferential surface is directed downwardly, and does not 
act on the document 262. Hence, the above correction of the inclination of 
the document 262 is not obstructed by the feed roller 46 and the reversely 
rotating roller 50. 
When a predetermined time t.sub.4 has elapsed from the closing of the 
delivered document detector 74 by the delivered document 262, the solenoid 
246 of the spring clutch mechanism 242 is energized. The predetermined 
time t.sub.4, set by a timer T4 built in the controller 264, is set so 
that the solenoid 246 is energized after some delay from the time when the 
feed roller 46 is stopped after one turn. When the solenoid 246 is 
energized, the conveyor roller means 22 begins to be rotated 
counterclockwise in FIGS. 14-C and 14-D, and the document 262 begins to be 
introduced onto the transparent plate 8. As stated above, at this point of 
time, the rear portion of the document 262 still is between the feed 
roller 46 and the reverse-rotating roller 50, but the feed roller 46 is at 
a stop at such an angular position that the cut 48 formed on its outer 
circumferential surface faces downwardly and does not act on the document 
262. Accordingly, the above introduction of the document 262 is not 
hampered by the feed roller 46 and the reverse rotating roller 50. When 
the introduction of the document 262 proceeds by the conveyor roller means 
22, the trailing edge of the document 262 goes past the delivered document 
detector 74, and therefore the detector 74 is deactuated, as shown in FIG. 
14-D. A counter C1 built in the controller 264 counts the number of pulses 
produced by the photoelectric rotating detector 254 from the time when the 
solenoid 246 is energized and the conveyor roller means 22 begins to be 
rotated clockwise in FIG. 14-D to the time when the delivered document 
detector 74 is deactuated and maintains this counted value n.sub.1 until 
the counter is reset in order to count the number of pulses again with 
respect to the next document. The counted value n.sub.1 maintained by the 
counter C1 corresponds to the length of the document 262 that has been 
introduced. The counted value n.sub.1 is large when the document 262 is 
long and is small when the document 262 is short. Another counter C2 is 
built in the controller 264 starts to count the number of pulses produced 
by the photoelectric rotation detector 254 from the time when the 
delivered document detector 74 is deactuated. When the counted value of 
the counter C2 reaches a predetermined value n.sub.2 (for example, 50), 
the supply of voltage for rotating the motor 178 in the normal direction 
is stopped. Simultaneously, voltage for rotating the motor 178 reversely 
is supplied only for a very short period of time t.sub.5 set by a timer T5 
built in the controller 264. The solenoid 246 is deenergized as soon as 
the reverse rotation of the motor 178 stops. The supply of voltage to the 
motor 178 for reverse rotation for a short time t.sub.5 of, for example, 
about 27 ms applies a braking action on the motor 178, which has so far 
rotated in the normal direction, to prevent idler running of the motor 178 
by inertia and to stop the normal rotation of the motor 178 precisely at 
the required point of time. When the normal rotation of the motor 178 
stops, the introduction of the document 262 is over. As shown in FIG. 
14-E, it is important that the trailing edge of the introduced document 
262 should be held between the transparent plate 8 and the rollers 140, 
142 and 144 of the conveyor roller means 22, and precisely in agreement 
with a standard position of scanning and exposure on one edge portion of 
the transparent plate 8. The predetermined counted value n.sub.2 defining 
the time of starting the reverse rotation of the motor 178 for the very 
short period t.sub.5 after stopping of its normal rotation is stored in a 
variable memory M1 built in the controller 266 of the electrostatic 
copying machine 2 and is fed to the controller 264 of the automatic 
document conveying device 4 (this will be described further hereinafter). 
When the introduction of the document 262 is over, a copying process in the 
electrostatic copying machine 2 is started and the introduced document on 
the transparent plate 8 is optically scanned. When the optical scanning of 
the document is terminated, a signal is fed from the controller 266 of the 
electrostatic copying machine 2 to the controller 264 of the automatic 
document conveying device 4. As a result, the controller 264 starts 
reverse rotation of the motor 178, and simultaneously the solenoid 246 is 
energized to avoid occurrence of noises. Thus, the conveyor roller means 
22 begins to rotate clockwise in FIGS. 14-E and 14-F. As a result, the 
document 262 is delivered to the left in FIG. 14-F from the transparent 
plate 8, deflected upwardly by the guiding means 168, and discharged onto 
the document receiving surface (the upper surface of the main portion 86 
of the opening-closing frame 16) through the discharge opening 96 by the 
action of the conveyor roller means 22 and the follower roller 166 
cooperating with it. When the reverse rotation of the motor 178 is started 
as above, the counter C3 built in the controller 264 begins to count 
pulses produced by the photoelectric rotation detector 254. When the 
counted value of the counter C3 reaches a value equaling the counted value 
n.sub.1 maintained by the counter C1 plus a predetermined value n.sub.3, 
the reverse rotation of the motor 178 is stopped. The counted value 
n.sub.1, maintained by the counter C1, corresponds to the length of the 
introduced document 262 as stated above, and the predetermined value 
n.sub.3 is set at the smallest value required for document delivery. 
Hence, the motor 178 is reversely rotated only for the minimum required 
period of time according to the length of the introduced document 262, and 
the wasteful consumption of power and time by the unnecessary reverse 
rotation of the motor 178 can be circumvented. 
When the next document 262 exists on the document table 18 and the set 
document detector 72 is actuated after discharging the document 262 as 
above, the rotation of the motor 178 in the normal direction is 
automatically started and the delivery of the next document 262 is also 
started. The above operating procedure is then repeated. 
The introduced position of the document 262, which should be precisely set 
as described above, depends upon the predetermined value n.sub.2 stored in 
the variable memory M1 built in the controller 266 of the electrostatic 
copying machine 2. When it is desired to change the predetermined value 
n.sub.2 for microadjustment or the intentional change of document 
positioning, switches or keys disposed on the operating panel 14 of the 
electrostatic copying machine 2 are operated, for example, in the 
following manner. 
First, a clear key CK and the copy start button PS are depressed 
simultaneously. As a result, the controller 266 is in condition for 
accepting changes in the numerals set in the various memories. Then, by 
operating copy number setting keys NK1 and NK2, a simulation number, for 
example "87", for changing the predetermined value n.sub.2 is selected so 
that the number "87" is displayed on a copy number displayer ND. Thus, the 
code "d" of the predetermined number n.sub.2 and its memorized number, for 
example "50", are displayed on a copy magnification displayer MD. Then, by 
operating copy magnification change keys MC1 and MC2, the number "50" is 
changed to the desired number and thus, the number stored in the memory M1 
is changed. When the clear key CK and the copy start button PS are then 
depressed simultaneously, the electrostatic copying machine 2 is returned 
to a normal state. 
In the illustrated embodiment, the above predetermined value n.sub.2 is 
stored in the memory M1 built in the controller 266 of the electrostatic 
copying machine 2 and is fed into the controller 264 of the automatic 
document conveying device 4. Accordingly, without the need to provide 
switches and keys and displayers additionally for exclusive use, the 
predetermined value n.sub.2 can be changed easily by utilizing the 
switches and keys and displayers disposed on the operating panel 14 of the 
electrostatic copying machine 2. If the predetermined value n.sub.2 is 
stored in a memory of the controller 264 of the automatic document 
conveying device 4, various switches and keys and displayers must be 
provided additionally in the automatic document conveying device 4 in 
order to permit changing of the predetermined value n.sub.2. This leads to 
increased cost of constructing the automatic document conveying device 4. 
While the present invention has been described with reference to preferred 
embodiments of the automatic document conveying device of the invention 
shown in the accompanying drawings, it should be understood that the 
invention is not limited to these preferred embodiments alone, and various 
changes and modifications are possible without departing from the scope of 
the invention.