Printing paper conveying apparatus for photographic printing apparatus

An apparatus for and a method of conveying a printing paper imprinted with an image by a printing device to a developing apparatus. The conveying apparatus includes a cutter for cutting the image printed printing paper for every image, and contacting and releasing apparatus for raising and conveying a piece of the cut printing paper and for releasing a holding condition of the printing paper. In consequence, a plurality of the pieces of the cut printing paper can be maintained between the printing apparatus and the developing apparatus without overlapping thereof.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to a printing paper conveying apparatus for a 
photographic printing apparatus which prints an image of a negative film 
to a photographic paper, and more particularly, to a conveying apparatus 
to convey a printed photographic paper to a developing apparatus. 
2. Description of the Related Art 
In a conventional photographic printing apparatus, there are many types of 
the apparatus in which a rolled printing paper is fed from its beginning 
portion to a printing section and, after printing, a printed photographic 
paper is cut for every image and the printed cut paper is then fed to a 
developing section. 
In the above-described type of the photographic printing apparatus, speed 
for developing the printed photographic paper in the developing section is 
lower at a uniform rate, though speed for feeding the printed photographic 
paper from the printing section to the developing section is higher and 
feeding thereof is intermittently made. Therefore, an apparatus for 
holding a continuous printed photographic paper in a loop is used to 
adjust discrepancy in both speeds of those sections. However, if a printed 
image on the photographic paper is larger, the holding apparatus must be 
large size. Moreover, since a portion of the printed photographic paper 
which is not developed immediately after printing operation is produced, 
the printing operation for a latter piece of photographic paper has to be 
suspended until after a former printed photographic paper has been fed 
into a developing section due to the difference in the speeds of the 
operations conducted in the both printing and developing section, although 
it is preferable to cut the printed photographic paper at every image and 
to feed them to the developing section immediately after printing thereof. 
SUMMARY OF THE INVENTION 
In view of the aforementioned problems of the conventional conveying 
apparatus, an object of the present invention is to provide a printing 
paper conveying apparatus for a photographic printing apparatus to keep a 
printed photographic paper between a printing apparatus and a developing 
apparatus. 
The present invention is a printing paper conveying apparatus for conveying 
a photographic printing paper from a printing apparatus to a developing 
apparatus in the photographic printing apparatus and is comprised of a 
cutter for cutting the printed photographic paper, and holding and 
conveying means for conveying pieces of printed cut photographic paper 
while holding and raising them for conveyance, and releasing them 
thereafter. 
As stated above, in the present invention, the printed photographic paper 
is cut out by the cutter, and is raised and fed to the developing 
apparatus by means of the holding and conveying means. Since the holding 
and conveying means can release the printing paper when necessary, in the 
state where a former piece of the printed photographic paper has not yet 
certainly been fed into the developing apparatus, a latter piece of the 
printed photographic paper is released from holding condition so as to 
prevent overlapping the former and later pieces thereof. 
The holding and conveying means includes rollers which are disposed at both 
sides of a printing paper conveying path and are releasably, contacted 
therebetween. Therefore, the printing paper can certainly and easily be 
held and released by the contact and release of the rollers. 
Further, the holding and conveying means can make a plurality of pairs of 
rollers which are disposed at both the sides of the printing paper 
conveying path independently separable and releasable from each other, and 
a part thereof can be driven at the same speed as the developing speed. 
This enables the intervals between a plurality of pieces of the printed 
photographic paper conveyed to be narrowed.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Preferred embodiments of the present invention will be described below with 
reference to the accompanying drawings. 
Referring first to FIG. 1, a photographic printing apparatus includes a 
printing paper accommodating portion 12, a printing section 16, a 
conveying apparatus 18 as holding and conveying means, and a developing 
section 20. 
A photographic or printing paper accommodated in the accommodated portion 
12 is fed to the printing section where an image on a negative film is 
exposed on the printing paper, and is fed to the developing section 20 
through the conveying apparatus 18. 
The printing paper accommodating portion 12 accommodates a roll of 
non-exposed printing paper 14. The printing paper 14 is fed continuously 
to the printing section 16 by a pair of holding and conveying rollers 22 
and 24 and holding and conveying rollers 26, 28, and 30. The holding and 
conveying roller 26 is driven by a motor 31 so as to allow the printing 
paper 14 to be held and conveyed between the holding and conveying roller 
26 and the holding and conveying rollers 28 and 30. 
After the image on the negative film which is not shown in the drawings is 
printed on the printing paper 14, it is fed to a cutter apparatus 38 by a 
pair of holding and conveying rollers 32 and 34 driven by the motor 31 
The conveying device 18 has a fixed frame 40 and a movable frame 42 which 
can be approached and separated each other as shown in FIGS. 2-4, and 7. 
The fixed frame 40 has leg plates 40A and 40B disposed at right angles at 
the two sides thereof (the right and left ends thereof as viewed in FIG. 
3). And five supporting shafts 44 are horizontally disposed between the 
leg plates 40A and 40B in such a manner that they are separated from each 
other in the vertical direction. Each of the supporting shafts 44 has 
rollers 46 provided to an intermediate portion thereof. The rollers 46 
protrude through openings 47 formed in the fixed frame 40. A gear train 50 
is fixed to the end portions of the supporting shafts 44 which are 
penetrated through the leg plate 40A. The gear grain 50 is connected to an 
elevating motor 52. The elevating motor 52 drives the rollers 46 such that 
they convey the printing paper 14 at a speed which is much faster than 
that at which development is conducted in the developing portion 20. 
The movable frame 42 has leg plates 42A and 42B formed at the lateral ends 
thereof. Supporting shafts 54 are rotatably supported by the leg plates 
42A and 42B at positions at which they correspond to the supporting shafts 
44. Each of the supporting shafts 54 has a plurality of rollers 56 fixed 
thereto. The rollers 56 protrude through openings 43 formed in the movable 
frame 42 so that they can make contact with the outer peripheries of the 
corresponding rollers 46. Thus, the rollers 46 and 56 form a conveying 
path for the printing paper 14 therebetween. The printing paper 14 which 
has been fed out of the printing section horizontally in the direction 
indicated by an arrow A in FIG. 2 is raised and is then conveyed in the 
direction indicated by an arrow B through the conveying path. 
The fixed frame 40 and the movable frame 42 are respectively provided with 
ribs 40C and 42C which protrude toward the conveying path (see FIG. 7). 
Arms 58 and ,60 extend from the leg plates 42A and 42B, respectively. The 
forward and proximal end portions of each of the arms 58 and 60 are 
respectively provided with long holes 62 and 63 which are elongated in the 
longitudinal direction. Supporting rollers 64 and 65 supported by the leg 
plate 40A or 40B are inserted into the holes 62 and 63, respectively. This 
allows the movable frame 42 to move parallel toward and away from the 
fixed frame 40 (in the horizontal direction as viewed in FIG. 2) so as to 
open and close the conveying path of the printing paper. 
As shown in FIG. 3, a driving motor 66 is provided to the leg plate 40B. An 
endless belt 68 which is wound around the output shaft of the motor 66 is 
wound around a plurality of rotary shafts 70 which are provided in such a 
manner that they are separated from each other in the vertical direction, 
so as to rotate the rotary shafts 70. The rotary shafts 70 are rotatably 
supported by the leg plates 40A and 40B. A cam 72 is fixed to each of the 
two ends of each of the rotary shafts 70 at a portion thereof which is 
located inside the leg plates 40A or 40B. The cams 72 are engaged with 
rollers 73 rotatably supported by the arms 58 and 60 so as to allow the 
movable frame 42 to move toward and away from the fixed frame 40 when the 
driving motor 66 is rotated. The forward ends of the rollers 73 are 
inserted into elongated holes 76 formed in the leg plates 40A and 40B and 
are located inside the leg plates 40A and 40B. The movable frame 42 is 
urged toward the fixed frame 40 by an elastic body (not shown). Each of 
the arms 58 and 60 has an elongated hole 78 which receives the end portion 
of the corresponding rotary shaft 70 which extends through the leg plate 
40A or 40B. 
A sensor 501 for detecting a forward end of the printing paper is disposed 
above the lowest supporting shafts 44 and 45 in the five supporting shafts 
which are separated from each other in the vertical direction. 
A roller 80 is disposed right above the uppermost rollers 46 at one side of 
the conveying path for the printing paper 14 while a movable roller 82 is 
provided above the uppermost rollers 56 at other side of the conveying 
path. The rollers 80 and 82 and the conveying apparatus 18 in combination 
form a holding and conveying means. The roller 80 is supported by a shaft 
80A which is rotatably supported on an extended frame 84 extending from 
the leg plates 40A and 40B, and the roller 82 is supported by a shaft 82A 
which is accommodated in guide grooves 86 formed in brackets 85 fixed to 
the extended frame 84, in such a manner that it can move toward and away 
from the roller 80. The movable roller 82 is urged by a spring (not shown) 
in the direction in which it makes contact with the roller 80. However, 
the roller 82 is moved away from the roller 80 by the actuation of a 
solenoid 88. To achieve this movement of the roller 82, the intermediate 
portion of a locker arm 92 is pivotally supported on the extended frame 84 
by pins 90. One end of the locker arm 92 faces the support shaft 82A, and 
the other end thereof is coupled to the solenoid 88 through a tension link 
94. As a result, when the solenoid 88 is actuated, the locker arm 92 is 
pivoted counterclockwise as shown in FIG. 5 so as to allow the movable 
roller 82 to move away from or release the roller 82. The roller 82 is in 
contact with the roller 80 while the solenoid 88 is not actuated. 
Guide plates 96 and 98 are provided at downstream portion of the rollers 80 
and 82. The guide plates 96 and 98 are connected to the printing paper 
conveying path formed between the fixed frame 40 and the movable frame 42, 
and are adapted to send the printing paper 14 to the developing section 20 
after having changed the direction of the printing paper 14 substantially 
in the horizontal direction. 
A gear 100 is fixed to one end of the roller supporting shaft 80A. An 
endless belt 102 which is wound around the gear 100 is also wound around 
gears 104 and 106 in such a manner that it substantially forms a 
triangular form. 
A large gear 110 is fixed to a rotary shaft 108 to which the gear 104 is 
fixed. A gear 111 which is engaged with the large gear 110 is fixed to a 
support shaft 111A, and a rotary arm 112 is pivotally supported by the 
shaft 111 A coaxially with respect to the gear 111. A support arm 113 
extends from part of the rotary arm 112. A planetary gear 116 and a 
coupling gear 120 are rotatably supported by the support arm 113 through a 
support shaft 114 and a support shaft 118, respectively. The planetary 
gear 116 is in mesh with the coupling gear 120 and a gear 121. The gear 
121 is coupled to the gear 111 through the support shaft 111A. As a 
result, when the rotary arm 112 is pivoted clockwise from a state shown by 
the solid line to a state shown by the imaginary line in FIG. 5, the 
coupling gear 120 engages with a transmission gear 122 which is driven by 
a motor (not shown) in the developing section 20. 
This allows the rotary force generated in the developing section 20 to be 
transmitted to the roller 80 in the state shown by the imaginary line in 
FIG. 5. The roller 80 is stopped when the rotary arm 112 is in the state 
shown by the solid line. 
A tension coil spring 128 is provided between the support shaft 114 and a 
pin 126 of the extended frame 84. The tension coil spring 128 passes the 
axis of the support shaft 111A and moves to the opposite side thereof when 
the rotary arm 112 is pivoted from the state shown by the solid line to 
the state shown by the imaginary line, by which the rotary arm 112 is 
pivoted in a snap action between the states shown by the imaginary line 
and the solid line. 
A conveying roller 134 is fixed to the rotary shaft 108 on which the gear 
104 is mounted. The conveying roller 134 is disposed at one side of the 
printing paper 14 which is conveyed in the horizontal direction, in such a 
manner that it is in contact with a roller 136 rotatably provided on the 
other side of the printing paper 14 so as to drive the printing paper 14. 
A sensor 502 for mainly detecting the rear end of the printing paper 14 is 
disposed between the pair of rollers 46 and 56 and the pair of rollers 80 
and 82, and a sensor 503 for mainly detecting the forward end of the 
printing paper 14 is provided between the pair of rollers 80 and 82 and 
the pair of rollers 134 and 136. 
Next, the operation of this embodiment will be described below. 
The printing paper 14 of the roll accommodated in the printing paper 
accommodating portion 12 is drawn out to the printing section 16 by the 
holding and conveying rollers 22 and 24 as well as by the rollers 26, 28 
and 30 so as to print the image thereon from a negative (not shown). 
Thereafter, in step 201 of the processing shown in FIG. 8, determination is 
made as to whether or not the movable frame 42 is at an opened position 
where it is separated from the fixed frame 40, that is, whether or not the 
movable frame 42 of the conveying device 18 has been moved away from the 
fixed frame 40. If the answer is negative, the movable motor 66 is 
actuated so as to rotate the cams 72 and thereby separate the movable 
frame 42 from the fixed frame 40 (in Step 202). 
If the answer is affirmative, the elevating motor 52 is driven so as to 
rotate the rollers 46 in Step 204, and the motor 31 is driven a 
predetermined number of pulses in Step 206. Subsequently, it is determined 
whether or not the forward end portion of the printing paper 14 has passed 
the sensor 501. If not, the process goes to Step 209 where the 
determination result is processed as an error. If it has been determined 
that the forward end of the printing paper 14 has passed the sensor 501, 
the elevating motor 52 is stopped in Step 210, and the cutter 38 is 
actuated so as to cut the printing paper at the rear end of the portion 
thereof which carries an image in Step 212. 
Thereafter, in Step 214 it is determined whether or not X msec has elapsed 
following the passage past the sensor 502 of the piece of printing paper 
14 which was conveyed in the preceding process. As the former piece of 
printing paper on which printing was conducted last time had been fed to 
the developing section 20 by the time the printing operation for the 
latter piece of printing paper is started, a decision is made that at 
least X msec has elapsed. 
After X msec has passed, the opening motor 66 is actuated in Step 216 to 
move the movable frame 42 close to the fixed frame 40 and thereby bring 
the rollers 56 into contact with the rollers 46, and at the same time the 
elevating motor 52 is actuated in Step 218 so as to rotate the rollers 46 
and 56. Furthermore, in Step 220, the solenoid 88 is actuated so as to 
release the movable roller 82 from the roller 80. The rotary arm 112 is 
set beforehand to the state shown by the imaginary lines in FIGS. 3 and 5 
so as to allow the rollers 80 and 134 to be driven at a speed at which the 
printing paper is conveyed in the developing portion. 
Thereafter, it is determined in Step 222 whether or not the forward end of 
the printing paper 14 has been detected by the sensor 503. If the forward 
end of the printing paper 14 is not detected within a predetermined time, 
the process goes to steps 223 and 225 where the determination result is 
processed as an error. If the forward end of the printing paper 14 is 
detected within the predetermined time, the solenoid 88 is de-energized in 
Step 224 so as to bring the movable roller 82 into contact with the roller 
80. At the same time, the opening motor 66 is rotated so as to move the 
movable frame 42 away from the fixed frame 40 in Step 226, and the 
elevating motor 52 is stopped in Step 228. These allow the printing paper 
to enter the developing section 20 in the direction indicated by the arrow 
B under the action of the pair of rollers 80 and 82 and the conveying 
rollers 134 and 136 which are driven at the same speed as which the 
printing paper is conveyed in the developing section 20. At this time, 
since the rear end of the printing paper 14 is not held by the rollers 46 
and 56, the printing paper is not subjected to any external force. 
Thereafter, it is determined in Step 230 whether or not a conveyance stop 
button (not shown) has been pressed. If the conveyance stop button has 
been pressed, the operation stops in the printing paper accommodating 
portion 12, the printing section 16, and the conveying device 18, except 
for the developing section 20. If it is determined that the button has not 
been pressed, Z msec is allowed to pass in Step 232 before the subsequent 
process is started, and then the process returns to Step 201. 
The period of X msec indicated in Step 214 will be described in detail 
below. 
The period X msec represents the time from when the rear end of the former 
piece of printing paper passes the sensor 502 to when conveyance of the 
latter piece of printing paper is started. Assuming that both the former 
and latter pieces of printing paper are conveyed in the developing section 
20 at an interval of d mm, the time t.sub.1 that it takes for the former 
piece of printing paper to reach the position which is d mm upstream of 
the sensor 503 after it has passed the sensor 502 is expressed by the 
following equation: 
##EQU1## 
where l.sub.1 is the distance from the cutter 38 to the sensor 503, 
l.sub.2 is the distance from the cutter 38 to the sensor 502, and p is the 
speed at which the printing paper 14 is conveyed in the developing section 
20. The time t.sub.2 that it takes for the latter piece of printing paper 
to reach the sensor 503 after having passed through the conveying 
apparatus is expressed as follows 
##EQU2## 
where L is the length of the piece of printing paper, a is the speed at 
which the movable frame 42 is moved away from the fixed frame 40, and V is 
the linear velocity at which the rollers 46 and 56 are driven by the 
elevating motor 52. Thus, the X msec is obtained by the following 
equation: 
##EQU3## 
The selection of the obtained value X enables the former and latter pieces 
of printing paper to be conveyed in the developing section 29 at an 
interval d. 
Next, the period of Z msec indicated in Step 232 represents the time from 
when the forward end of the former piece of printing paper passes the 
sensor 503 to when the latter piece of printing paper is fed out into the 
conveying apparatus by the motor 31. Assuming that the latter piece of 
printing paper (having a length L.sub.1) has passed the enters the 
conveying apparatus 18 immediately after the former piece of printing 
paper (having a length L.sub.1) has passed the sensor 503, the overlap S 
between the latter piece of printing paper and the former piece of 
printing paper is expressed by the following equation: 
EQU S=L.sub.1 +L.sub.2 -l.sub.1 (4) 
Where Z msec is the time delay and P mm/sec is the speed at which the 
printing paper is conveyed in the developing section, the overlap S is 
expressed as follows: 
EQU S=L.sub.1 +L.sub.2 -l.sub.1 -P.multidot.Z (5) 
If S=0, Z is obtained by the following equation: 
##EQU4## 
Thus, the former and latter pieces of printing paper can be fed to the 
developing section 20 without overlapping each other when the latter piece 
of printing paper is fed into the conveying apparatus Z msec after the 
former piece of printing paper has passed the sensor 503. 
Table 1 lists values for X and Z obtained when l.sub.1 =768 mm, l.sub.2 
=726 mm, the linear velocity of the conveying apparatus 18 is 157 mm/sec 
at a frequency of 50 Hz and 188.5 mm/sec at a frequency of 60 Hz, a is 0.3 
sec at a frequency of 50 Hz and 0.25 sec at a frequency of 60 Hz, d is 30 
mm, and p is 9.5 mm/sec. 
TABLE 1 
______________________________________ 
L mm X msec 50 Hz X msec 60 Hz 
Z msec 
______________________________________ 
152 mm 3.36 4.06 -- 
203 mm 3.68 4.33 -- 
254 mm 4.01 4.60 -- 
305 mm 4.33 4.87 -- 
356 mm 4.66 5.14 -- 
456 mm 5.30 5.68 15.4 
______________________________________ 
The former and latter pieces of printing paper can be fed at a sufficient 
interval and without overlapping each other, if they are conveyed using 
the above-listed X msec and Z msec values. When L mm is 384 mm or less, Z 
msec becomes a negative value which is substantially 0 sec. 
In the above-described embodiment, the movable frame 42 is moved to 
approach or to separate from the fixing frame 40 by a combination of motor 
and cams shown in FIGS. 1 and 2. However, they can be driven by any other 
means. 
Next, a second embodiment of the present invention will be described below 
with reference to FIGS. 9 and 10. This embodiment is designed to prevent 
the printing paper from falling within the conveying apparatus 18. 
More specifically, a one-way clutch 50A is provided between each of the 
gears in the gear train 50 and each of the supporting shafts 44, as shown 
in FIG. 9. The one-way clutch 50A is composed of a ring 50B fixed to each 
of the gears in the gear train 50, and balls 50D interposed between the 
inner peripheral surface 50C of the ring 50B and the supporting shaft 44. 
This one-way clutch 50A allows the rollers 46 to rotate only in the 
direction in which the printing paper 14 held by the rollers 46 is 
elevated (the direction indicated by the arrows L) but not to rotate it in 
the opposite direction in which the printing paper 14 falls by its own 
weight when the elevating motor 52 is stopped. 
In the flowchart shown in FIG. 10, steps 223A and 223B are added to the 
processing executed for the first embodiment. After the forward end of the 
printing paper has been detected by the sensor 503 in Step 222, the 
elevating motor 52 is stopped. Thereafter, a predetermined time (e.g., 1 
sec) is allowed to pass, and the movable roller 82 is brought into contact 
with the roller 80 in Step 224. Subsequently, a predetermined time (e.g., 
1 sec) is allowed to pass in Step 225, and the movable frame 42 is moved 
away in Step 226. 
Thus, the one-way clutch 50A prevents the printing paper 14 from falling by 
the time the movable roller 82 is brought into contact with the roller 80 
in Step 224, and the movable frame 42 is moved away after the movable 
roller 82 has been brought into contact It is therefore not necessary for 
the movable roller 82 to be brought into contact concurrently with the 
separation of the movable frame 42 from the fixed frame. 
The movable frame 42 may be approached to the fixed frame after Step 210 
has been executed and before Step 212 is executed. This means that the 
forward end of the piece of printing paper which is to be cut out is held 
by the frames, and shifting of the printing paper caused by the cutting 
can be prevented.