Sheet feed control system

A sheet feed control system for use in an image recording apparatus, for example, includes a suction cup for attracting a sheet-like member such as a photographic film under suction, a crank mechanism for moving the suction cup with respect to the sheet-like member, and a swinging mechanism for swinging the suction cup with the sheet-like member attracted thereto to impart swinging action to the sheet-like member. The crank mechanism is drived by a pulse motor in response to a control signal applied thereto, and the swinging mechanism is drived by a pulse motor in response to a control signal applied thereto. Information, such as rotational speeds and angular displacements, with regard to the pulse motors is stored in a memory, and desired information corresponding to certain physical properties of the sheet-like member, can be selected from the memory by the operator. A controller controls operation of the pulse motors to impart appropriate swinging action to the sheet-like member based on the selected information which is read from the memory.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to a sheet feed control system for 
automatically controlling a sheet feed mechanism which feeds sheet-like 
members such as unexposed photographic films in medical image recording 
apparatus. 
2. Prior Art 
Recently, there have widely been employed image recording apparatus in 
which image information produced by a computerized tomographic system or 
the like is displayed on a CRT display unit or the like, and the displayed 
image information is recorded on a photographic light-sensitive medium 
such as a photographic film and thereafter developed into a visible image 
for medical diagnosis or the like. 
In such an image recording apparatus, sheet-like members such as 
photographic light-sensitive mediums, which are stacked in a magazine, are 
taken out by a sheet feed mechanism, and then transported to an exposure 
position by a sheet transporting mechanism. 
It is necessary to feed photographic light-sensitive mediums, reliably one 
by one, from the magazine for subsequent correct exposure operation. To 
meet such a requirement, it has been customary to operate a suction cup or 
the like of the sheet feed mechanism with a combination of a motor as a 
drive source and mechanical elements that are operatively coupled to the 
motor. 
Since the operation of the sheet feed mechanism is determined solely by the 
operative interlinked coupling between the drive source and the mechanical 
elements, if physical properties of the sheet-like members are modified or 
the image recording apparatus is placed in a different environment, the 
sheet-like members may not be properly fed one at a time from the magazine 
because the basic operation of the sheet feed mechanism remains unchanged. 
If the sheet-like members were not properly fed from the magazine, desired 
images would not accurately be recorded on the sheet-like members. In the 
case where the image recording apparatus is used for medical diagnosis, it 
would be highly difficult or impossible for the doctor to make an 
appropriate diagnosis due to inaccurate or defective images. 
SUMMARY OF THE INVENTION 
It is a major object of the present invention to provide a sheet feed 
control system which selectively operates a driving source to drive a 
sheet feed mechanism based on physical properties of sheet-like members or 
the environment where the sheet-like members are used, so that the 
sheet-like members can properly be fed one at a time from a magazine. 
Another object of the present invention is to provide a sheet feed control 
system comprising, moving means for moving a suction cup to suck a 
sheet-like member with respect to the sheet-like member, a swinging means 
for attracted thereto to impart a swinging action to the sheet-like 
member, a first driving means for driving the moving means in response to 
a control signal applied thereto, a second driving means for driving the 
swinging means in response to a control signal applied thereto, a memory 
means for storing information with regard to the control signals applied 
to the first and second driving means, an information selecting means for 
selecting information corresponding to at least physical properties of the 
sheet-like member, from the information with regard to the control signals 
stored in the memory means, and a control means for reading the 
information selected from the memory means and controlling operation of 
the first and second driving means based on the selected information read 
from the memory means. 
Still another object of the present invention is to provide a sheet feed 
control system wherein the moving means comprises a crank mechanism 
derived by the first driving means. 
Yet another object of the present invention is to provide a sheet feed 
control system wherein the swinging means comprises a worm rotatable by 
the second driving means and a worm gear meshing with the worm, the 
suction cup being angularly movable with the worm gear about an axis 
coaxial with the worm gear. 
Yet still another object of the present invention is to provide a sheet 
feed control system wherein the swinging means includes an angle detecting 
means for detecting swinging angle of the sheet-like member in terms of 
swinging angle of the suction cup. 
A further object of the present invention is to provide a sheet feed 
control system wherein the angle detecting means comprises a rotary 
encoder. 
A still further object of the present invention is to provide a sheet feed 
control system wherein the information with regard to the control signals 
includes data on swinging movements and swinging speeds corresponding to 
physical properties, such as surface roughness and rigidity, of sheet-like 
members. 
A yet further object of the present invention is to provide a sheet feed 
control system wherein the information selecting means comprises means for 
selecting data on a smaller swinging movement and a lower swinging speed 
if the sheet-like member has a lager surface roughness and a larger 
rigidity, and for selecting data on a larger swinging movement and a 
higher swinging speed if the sheet-like member has a smaller surface 
roughness and a smaller rigidity. 
A yet still further object of the present invention is to provide a sheet 
feed control system wherein the control means comprises means for 
controlling operation of the first and second driving means according to 
control signals based on the data from the memory means and signals 
corresponding to the swinging angle detected by the angle detecting means. 
The above and other objects, features and advantages of the present 
invention will become more apparent from the following description when 
taken in conjunction with the accompanying drawings in which a preferred 
embodiment of the present invention is shown by way of illustrative 
example.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
FIG. 1 shows an image recording apparatus which incorporates therein a 
sheet feed control system according to the present invention. The image 
recording apparatus, generally denoted at 10, comprises a sheet feed 
mechanism 16 for taking out stacked sheet-like unexposed photographic 
light-sensitive mediums 14, one by one, from a magazine 12, a sheet 
transporting mechanism 18 for transporting an unexposed photographic 
light-sensitive medium 14, which has been taken out from the magazine 12, 
to an exposure station P, an exposure mechanism 20 disposed below the 
exposure station P, for exposing the photographic light-sensitive medium 
14 to image information, and another sheet transporting mechanism 24 for 
transporting an exposed photographic light-sensitive medium 14 to a 
magazine 22. 
In the sheet transporting mechanism 18, a photographic light-sensitive 
medium 14 is transported past a fixed roller 30 which is rotated by a 
motor 26 through a belt 28, and then transported while being reversed by a 
drum 32 and a belt 34 held in contact therewith. Then, the photographic 
light-sensitive medium 14 is transported along the outer circumferential 
surface of a drum by drive rollers 40, 42 which are rotated by a motor 36 
through a belt 38. At this time, the photographic light-sensitive medium 
14 is reversed again. The photographic light-sensitive medium 14 thus 
reversed again is transported to the exposure station P. 
In the exposure station P, a first belt conveyor 46 and a second belt 
conveyor 48 are placed in contact with each other in the horizontal 
direction. The photographic light-sensitive medium 14 is positioned in the 
exposure station P by the belt conveyors 46, 48 when they are rotated. 
After the photographic light-sensitive medium 14 has been exposed by the 
exposure mechanism 20, the belt conveyors 46, 48 are rotated in the 
opposite direction to direct the photographic light-sensitive medium 14 
toward the sheet transporting mechanism 24. The photographic 
light-sensitive medium 14 is transported by a drive roller 54 rotated by a 
motor 52 through a belt 50 and belt conveyors 56, 58 which are rotated by 
a motor (not shown), and stored in the magazine 22. The magazine 22 has a 
shutter 62 which has a rack held in mesh with a pinion 60. An opening 64 
present is opened and closed by the shutter 62 in the magazine 22. 
The exposure mechanism 20 has an image display device 68 for displaying 
image information on a CRT display unit 66, and an optical system 72 for 
projecting the image information displayed on the CRT display unit 66 onto 
the photographic light-sensitive medium 14 through a focusing lens 70. 
The image display device 68 and the optical system 72 are vertically 
movable along a guide rail 74, and the image display device 68, the 
optical system 72, and the guide rail 74 are movable along guide rails 76 
in a direction normal to the sheet of FIG. 1. Therefore, the image display 
device 68 and the optical system 72 are movable to an optimum position 
required for exposure of the photographic light-sensitive medium 14 to be 
exposed. 
As shown in FIG. 2, the sheet feed mechanism 16 comprises a suction cup or 
pad 80 for attracting or sucking a photographic light-sensitive medium 14 
and taking out the same from the magazine 12, a movable roller 82 movable 
toward and away from the fixed roller 30 of the sheet transporting 
mechanism 18, a crank mechanism (moving means) 84 for moving the suction 
cup 80 and the movable roller 82 into the magazine 12, and a pulse motor 
(first driving means) 86 for driving the crank mechanism 84. 
In order to give a flying or swinging action to a photographic 
light-sensitive medium 14 taken out from the magazine 12, the sheet feed 
mechanism 16 also has a swinging mechanism (swinging means) 88 for 
swinging the suction cup 80, a pulse motor (second actuator) 90 for 
driving the swinging mechanism 88, and a rotary encoder 92 for producing a 
pulse signal in response to movement of the movable roller 82 toward the 
fixed roller 30. 
The crank mechanism 84 comprises a disc member 94 rotatable by the pulse 
motor 86, a first arm 96 rotatably fixed at one end to the center of the 
disc member 94, and a second arm 98 rotatably supported on the other end 
of the first arm 96. The other end of the second arm 98 is rotatably 
supported in a casing 100 of the swinging mechanism 88 at a position about 
which the suction cup 80 is angularly movable. 
The casing 100 of the swinging mechanism 88 houses a worm 102 mounted on 
the output shaft of the pulse motor 90 and a worm gear 104 held in mesh 
with the worm 102. When the worm 102 is rotated by the pulse motor 90, the 
worm gear 104 rotates about a central axis Q thereof. 
The suction cup 80 is mounted on one end of a swinging rod 106, the other 
end of which is rotatably supported on the worm gear 104 at the central 
axis Q thereof. When the pulse motor 90 is energized, the suction cup 80 
is caused by the worm 102, the worm gear 104, and the swinging rod 106 to 
swing about the central axis Q. 
The movable roller 82 is rotatably mounted on an attachment member 108, 
which is angularly movably supported on the swinging rod 106 for angular 
movement about an axis R. The attachment member 108 has integral teeth 112 
along an arcuate edge thereof which are held in mesh with a pinion 110 
that is mounted on an input shaft of the rotary encoder 92. 
Upon swinging movement of the swinging rod 106, the attachment member 108 
and the movable roller 82 swing about the central axis Q. At this time, 
the attachment member 108 also swings about the axis R, so that the input 
shaft of the rotary encoder 92 rotates. As a result, the rotary encoder 92 
produces a pulse signal corresponding to the angle through which the input 
shaft of the rotary encoder 92 rotates. More specifically, the number of 
pulses produced by the rotary encoder 92 varies depending on the angle to 
which the movable roller 82 swings about the axis R through the attachment 
member 108. 
The attachment member 108 is limited in its swinging movement by a stopper 
pin 114 when the stopper pin 114 abuts against the swinging rod 106. When 
the attachment member 108 swings downwardly due to the weight of the 
movable roller 82, the stopper pin 114 is brought into abutment against 
the swinging rod 106, thereby preventing the movable roller 82 from moving 
into a position near the lower suction surface of the suction cup 80. 
Therefore, the attracting or sucking operation of the suction cup 80 is 
not obstructed by the movable roller 82. 
It is now assumed, as shown in FIGS. 3 and 4, that a vertical straight line 
is represented by l.sub.1, and the axis R and the central axis of the 
movable roller 82 are interconnected by a straight line l.sub.2. In FIG. 
3, no photographic light-sensitive medium 14 is nipped between the movable 
roller 82 and the fixed roller 30. In FIG. 4, a photographic 
light-sensitive medium 14 is nipped between the movable roller 82 and the 
fixed roller 30. When the swinging rod 106 swings to the right in FIG. 2, 
the angle .theta..sub.1 formed between the straight line l.sub.1 and the 
line indicating the longitudinal direction of the swinging rod 106 in the 
condition shown in FIG. 3 is equal to the angle .theta..sub.2 formed 
between the straight lines l.sub.2 and the line indicating the 
longitudinal direction of the swinging rod 106 in the condition shown in 
FIG. 4 (.theta..sub.1 =.theta..sub.3), but the angle formed between the 
straight line l.sub.2 and the line indicating the longitudinal direction 
of the swinging rod 106 is larger when the photographic light-sensitive 
medium 14 is nipped than when no photographic light-sensitive medium is 
nipped (.theta..sub.4 &gt;.theta..sub.2). Stated otherwise, when the movable 
roller 82 and the fixed roller 30 nips a photographic light-sensitive 
medium 14 therebetween, the movable roller 82 and the fixed roller 30 are 
spaced apart from each other by a distance H which corresponds to the 
thickness of the nipped photographic light-sensitive medium 14. 
If the position where the movable roller 82 is held in abutment against the 
fixed roller 30 with no photographic light-sensitive medium 14 nipped, as 
shown in FIG. 3, is a reference position, then the movable roller 82 is 
displaced from the reference position by the distance H when the 
photographic light-sensitive medium 14 is nipped between the movable 
roller 82 and the fixed roller 30. The angle .theta..sub.4 is therefore 
greater than the angle .theta..sub.2 by an angle .theta..sub.5 which 
corresponds to the distance H. The angle .theta..sub.5 which is the 
difference between the angle .theta..sub.4 and the angle .theta..sub.2 is 
substantially proportional to the distance H. Measurements are made 
beforehand of the thickness of a singe photographic light-sensitive medium 
14, the angle .theta..sub.5 when one photographic light-sensitive medium 
14 is nipped between the movable roller 82 and the fixed roller 30, and 
the number of pulses generated by the rotary encoder 92 when the movable 
roller 82 is angularly moved by the angle .theta..sub.5. In actual 
operation, when the number of pulses generated by the rotary encoder 92 is 
measured, the distance H by which movable roller 82 is spaced from the 
reference position can be calculated, and as a result the number of 
photographic light-sensitive mediums 14 which have been taken out of the 
magazine 12 can be calculated. 
FIG. 5 shown in block form a major electric arrangement of the image 
recording apparatus 10. As shown in FIG. 5, a controller 200 comprises a 
CPU 202 serving as a control means, a program ROM 204 which stores a 
program for operating the CPU 202 according to a predetermined procedure, 
and a working RAM 206 for storing various data. The CPU 202 controls 
operation of the sheet feed mechanism 16, the sheet transporting 
mechanisms 18, 24, the image display device 68, the optical system 72, a 
control console 208, and other controllable components (e.g., the drive 
rollers 40, 42) according to the program stored in the program ROM 204. 
The ROM 204, serving as a memory means, stores rotational speeds and 
angular displacements of the pulse motors 86, 90, which correspond to 
physical properties of different photographic light-sensitive mediums 14, 
such as surface roughness and rigidity. As illustrated in FIGS. 6(a) 
through 6(c), the ability of the suction cup 80 to retain the photographic 
light-sensitive medium 14 becomes poorer as the swinging movement given to 
the photographic light-sensitive medium 14 is larger, as the surface 
roughness of the photographic light-sensitive medium 14 is larger, and as 
the rigidity of the photographic light-sensitive medium 14 is larger. 
As shown in FIGS. 7(a) through 7(d), the ease with which the photographic 
light-sensitive medium 14 is fed from the cassette 12, or the feedability 
of the photographic light-sensitive medium 14, becomes greater as the 
swinging movement given to the photographic light-sensitive medium 14 is 
larger, as the surface roughness of the photographic light-sensitive 
medium 14 is greater, and as the rigidity of the photographic 
light-sensitive medium 14 is larger, but becomes poorer as the swinging 
speed or the photographic light-sensitive medium 14 is higher. 
In view of the foregoing considerations, if a photographic light-sensitive 
medium 14 has a large surface roughness and a high rigidity, then it can 
well be fed from the magazine 12 when the swinging movement given to the 
photographic light-sensitive medium 14 is small and the swinging speed 
thereof is low. If a photographic light-sensitive medium 14 has a smooth 
surface and is less rigid, then it can well be fed from the magazine 12 
when the swinging movement is larger and the swinging speed is low. 
As shown in FIG. 8(a), the relationship between the swinging speed and a 
swinging effect to reliably feed a single photographic light-sensitive 
medium 14 from the magazine is represented by a curve .alpha.. As shown in 
FIG. 8(b), the relationship between the swinging movement given to a 
photographic light-sensitive medium 14 and the swinging effect with 
respect to the photographic light-sensitive medium 14 is represented by a 
curve .beta.. 
The rotational speeds and angular displacements of the pulse motors 86, 90, 
which are stored in the ROM 204 as information with regard to control 
signals to be given to the pulse motors 86, 90, are representative of such 
swinging speeds and swinging movements to be given to photographic 
light-sensitive mediums 14. 
The swinging speeds and swinging which are thus stored in the ROM 204 can 
be by the operator through the control console 208 depending on the 
surface roughness and rigidity of a light-sensitive medium 14 used. Stated 
otherwise based on the information entered through the control 208, the 
CPU 202 selects a control signal stored in and corresponding to the 
entered information, and operation of the pulse motors 86, 90 according to 
the selected control signal. 
Ambient data regarding environments of the image recording apparatus 10, 
such as a temperature, a humidity, etc. may be stored in the ROM 204 as 
control signal information which will be used to select a swinging speed 
and a swinging movement. 
A processing sequence to be executed by the CPU 202 will be described below 
with reference to the flowcharts shown in FIGS. 9 through 12. 
When the power supply of the controller 200 is turned on, the CPU 202 
starts to control the image recording apparatus. First, the pulse motor 86 
is swung in a normal direction to move the suction cup 80 toward the 
photographic light-sensitive medium 14 in the magazine 12 at a speed Va in 
a step S1 (FIG. 9). Angular movement of the movable roller 82 through a 
certain angle is confirmed by an electric signal which is read from the 
rotary encoder 92 into the CPU 202. When it is confirmed by such an 
electric signal that the movable roller 82 contacts the photographic 
light-sensitive medium 14 in a step S2, the rotational speed of the pulse 
motor 86 is lowered to move the suction cup 80 at a speed Vb lower than 
the speed Va in a step S3. The suction cup 80 now starts attracting or 
sucking the photographic light-sensitive medium 14 in a step S4. 
If the attracting action is finished in a step S5 and completed within a 
predetermined period of time in a step S6, then the pulse motor 86 is 
de-energized in a step S7. Thereafter, the pulse motor 86 is reversed, or 
swung in a reverse direction to move the suction cup 80 in the opposite 
direction away from the magazine 12 in a step S8. 
In this embodiment, the suction cup 80 is placed in a predetermined 
position when it imparts a swinging action to the photographic 
light-sensitive medium 14. If it is confirmed that the suction cup 80 has 
moved to a given swinging station in a step S9, then the pulse motor 86 is 
de-energized in a step S10, and the pulse motor 90 is energized in a 
normal direction in a step S11. 
If the suction cup 80 has been moved to a given swinging station by the 
pulse motor 90 in a step S12, then the pulse motor 90 is de-energized and 
energized in a reverse direction in a step S13. The pulse motor 90 is 
continuously reversed in a step S14 (FIG. 10). If the suction cup 80 has 
reached the swinging station again in a step S15, then the pulse motor 90 
is de-energized in a step S16 and the pulse motor 86 is energized in the 
reverse direction in a step S17. The suction cup 80 therefore moves away 
from the magazine 12. If the suction cup 80 moves to a reference station 
in which the movable roller 82 and the fixed roller 30 nip the 
photographic light-sensitive medium 14 in a step S18, the pulse motor 86 
is de-energized in a step S19 and the pulse motor 90 is swung in the 
reverse direction in a step S20. If it is confirmed that the movable 
roller 82 and the fixed roller 30 contact each other in a step S21, then 
the pulses of a pulse signal generated by the rotary encoder 92 are 
counted in a step S22. If the movable roller 82 moves to a station 
(nipping station) for the movable roller 82 and the fixed roller 30 to nip 
the photographic light-sensitive medium 14 in a step S23, then the pulse 
motor 90 is de-energized in a step S24, and the number of photographic 
light-sensitive mediums 14 that have been fed out of the magazine 12 is 
calculated from the number of pulses counted in a step S22, in a step S25 
(see FIGS. 3, and 4). 
If it is confirmed that only one photographic light-sensitive medium 14 has 
been fed so far in a step S26 (FIG. 11), the sucking action of the suction 
cup 80 is stopped in a step S27, thereby releasing the photographic 
light-sensitive medium 14 from the suction cup 80. Then, the fixed roller 
30 is swung to transport the photographic light-sensitive medium 14 with 
the sheet transporting mechanism 18 in a step S28. If the sheet 
transporting operation is stopped in a step S29, the rotation of the fixed 
roller 30 is stopped in a step S30. 
Then, the pulse motor 90 is energized in the reverse direction in a step 
S31. If the suction cup 80 reaches the reference station (standby station) 
in a step S32, then the pulse motor 90 is de-energized in a step S33. 
If the photographic light-sensitive medium 14 is not attracted in the 
predetermined period of time in the step S6, then the pulse motor 86 is 
energized in the reverse direction in a step S35 (FIG. 12). If it is 
confirmed that the suction cup 80 reaches the reference station in a step 
S36, then the pulse motor 86 is de-energized in a step S37, and the 
processing is finished. The flowchart shown in FIG. 12 is concerned with 
the processing when no photographic light-sensitive medium is contained in 
the magazine 12. 
If it is determined in the step S26 that the magazine 12 still contains two 
or more photographic light-sensitive mediums 14, then the stepping motor 
90 is energized in the reverse direction in a step S38. If the suction cup 
80 is determined as having reached the reference station in a step S39, 
the pulse motor 90 is de-energized in a step S40, and the pulse motor 86 
is energized in the reverse direction in a step S41. Thereafter, control 
returns to the step S8 to repeat the steps following the step S8. 
With the aforesaid embodiment, as described above, the sheet feed mechanism 
16 has the crank mechanism 84 including the pulse motor 86 as an actuator 
and the swinging mechanism 88 with the pulse motor 90 as an actuator. Data 
regarding swinging speeds and swinging movements for swinging or flying 
actions to be imparted to the photographic light-sensitive medium 14 are 
stored in the ROM 204. The stored data can be selected by the operator 
through the control console 208. Based on the swinging speed and swinging 
movement which are selected by the operator through the control console 
208, the CPU 202 controls operation of the pulse motors 86, 90 in order to 
impart a desired swinging or flying action to the photographic 
light-sensitive medium 14. 
The suction cup 80 is angularly moved in a manner to optimize the swinging 
action to be imparted to the photographic light-sensitive medium 14, 
depending on some physical properties of the photographic light-sensitive 
medium 14, such as the surface roughness, rigidity, etc. Therefore, the 
photographic light-sensitive medium 14 can reliably be fed out of the 
magazine 12 by the sheet feed mechanism 16. 
In the case where the image recording apparatus 10 and an external 
diagnostic system are connected through an interface for automatically 
photographing radiation images of a patient, it is possible to select the 
rotational speed of the pulse motor 86 so that the sheet feeding cycle can 
match the photographing cycle. 
The sheet-like members which can be handled in the sheet feed control 
system according to the present invention may be copy sheets or other 
sheets or films which are to be fed one by one, instead of photographic 
light-sensitive mediums. 
As described above, the sheet feed control system according to the present 
invention has a memory means for storing information regarding control 
signals which control operation of a first actuator for actuating a moving 
means and a second actuator for actuating a swinging means. The stored 
information can be selected by the operator through an information 
selecting means. In operation, desired information is read from the memory 
means by the operator, and the first and second actuators are controlled 
in operation by the control means based on the read information. 
a sheet-like member is therefore given a swinging or flying action which 
corresponds to physical properties of the sheet like member or 
environments in which the image reading apparatus is used. Accordingly, 
the sheet-like member can reliably be fed out of the magazine. 
Although a certain preferred embodiment has been shown and described, it 
should be understood that many changes and modifications may be made 
therein without departing from the scope of the appended claims.