U.S. patent number 3,876,116 [Application Number 05/328,357] was granted by the patent office on 1975-04-08 for electronic photocopying machine.
This patent grant is currently assigned to Minolta Camera Kabushiki Kaisha. Invention is credited to Teizo Kushima, Masaya Ogawa, Susumu Tanaka.
United States Patent |
3,876,116 |
Kushima , et al. |
April 8, 1975 |
ELECTRONIC PHOTOCOPYING MACHINE
Abstract
An automatic adjusting device for the concentration of a
developing solution in a photocopy machine, comprising a
concentration detecting and measuring system, an electronic
circuit, and a system for operating a valve of an inverted bottle
containing a concentrated developing solution and located above a
developing solution tank. The systems and circuit are so arranged
that the operation of opening the valve to introduce the
concentrated developing solution into the tank can automatically be
made with a certain and constant time interval by a photoelectric
current generated in response to the variation of concentration of
the developing solution which flows between a light source and a
photoelectric element, the operation being stopped when the
concentration of the developing solution reaches a predetermined
level.
Inventors: |
Kushima; Teizo (Osaka,
JA), Tanaka; Susumu (Osaka, JA), Ogawa;
Masaya (Osaka, JA) |
Assignee: |
Minolta Camera Kabushiki Kaisha
(Osaka, JA)
|
Family
ID: |
26954522 |
Appl.
No.: |
05/328,357 |
Filed: |
January 31, 1973 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
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270831 |
Jul 11, 1972 |
|
|
|
|
543226 |
Apr 18, 1966 |
3690759 |
Sep 2, 1972 |
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Current U.S.
Class: |
399/57; 118/602;
118/691; 222/638 |
Current CPC
Class: |
G03G
15/26 (20130101); G03G 15/105 (20130101) |
Current International
Class: |
G03G
15/26 (20060101); G03G 15/10 (20060101); G03G
15/00 (20060101); G03g 013/10 () |
Field of
Search: |
;118/7,8,4,DIG.23 ;355/3
;222/57,70 ;117/DIG.2,37LE |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Kaplan; Morris
Parent Case Text
This application is a continuation-in-part of Ser. No. 270,831
filed July 11, 1972, which in turn is a division of application
Ser. No. 543,226 filed Apr. 18, 1966 and issued as U.S. Pat. No.
3,690,759 on Sept. 2, 1972.
Claims
What is claimed is:
1. An automatic adjusting device for the concentration of a
developing solution in a developing solution tank of a photocopy
machine, said device comprising a supply of concentrated developing
solution, valve means for controlling the feed of the concentrated
developing solution from said supply to the developing tank,
photoelectric sensing means including a light source arranged
outside the developing tank, a photoelectric receiver also arranged
outside the developing tank and light guide means to guide the
light beam from the light source to the photoelectric receiver
through the solution in the developing tank, and electric means
coupled to the photoelectric receiver and to said valve means for
opening said valve means for a predetermined interval when the
concentration of the solution in the developing tank reaches a
minimum level and thereafter to hold said valve means closed for
another predetermined interval before re-opening to allow the
concentrated solution from said supply to be dispersed into the
solution in the developing tank.
2. A device as claimed in claim 1 wherein said circuit means
includes electromagnet means for operating said valve means.
3. A device as claimed in claim 1 wherein said supply is an
inverted vessel having a bottom opening with said valve means in
said opening.
4. A device as claimed in claim 3 comprising lever means for
opening and closing said valve means, said circuit means including
an electromagnet operatively coupled to said lever means to cause
the latter to open and close the valve means.
5. A device as claimed in claim 1 comprising a stirring means to
disperse the concentrated developing solution in the solution in
the developing tank.
6. A device as claimed in claim 5, wherein said stirring means is
arranged between said supply and said photoelectric sensing
means.
7. A device as claimed in claim 1, wherein said light guide means
comprises two hollow members having, respectively, a closed window
arranged opposite one another at a given distance, one of said
hollow members having a reflecting mirror to reflect the light beam
from the light source to the photoelectric receiver through the
closed windows and another reflecting mirror arranged in the other
hollow member.
8. A device as claimed in claim 1, wherein said light guide means
comprises two bundles of optical fibers, one of the bundles having
one end arranged near the light source another other end arranged
in the solution in the developing tank and opposite one end of the
other bundle which has another end arranged near the photoelectric
receiver.
9. A device as claimed in claim 1, wherein said light guide means
comprises two rods spaced from one another and made of an optical
material other than optical fiber having a regractive index of at
least n = 1.8 and having respectively, a free end cut obliquely and
arranged in the solution in the developing tank to reflect the
light beam from the light source to the photoelectric receiver
through the slanted ends.
10. A device as claimed in claim 2, wherein said circuit means
includes a first switch means controlling the operation of the
electromagnet means, means for effecting time delay in the closing
operation of the first switch means after any previous opening
operation of the valve means and comprising an R-C circuit, said
first switch means being a relay coupled to said R-C circuit to be
opened during discharge of a condenser of said R-C circuit, another
condensor in said circuit means in series with said first switch
means, and a second switch means in said R-C circuit having one
operative state to actuate the R-C circuit when the concentration
of the solution in the developing tank reaches a minimum level and
another operative state in which the condensor of the R-C circuit
will be charged.
Description
BRIEF SUMMARY OF THE INVENTION
The present invention relates to a copying machine of the type,
wherein zinc oxide powders (ZnO) or equivalent materials are
applied to surfaces of paper to produce sensitive papers which can
used by being exposed to rays of light after being negatively
electrified, and which are then developed and fixed to complete a
copying operation.
Particularly, the invention relates to a device for automatically
adjusting the concentration of a developing solution for electronic
photocopying, by detecting the concentration of the developing
solution, effecting strengthening of the developing solution by
selectively adding concentrated solution whenever the concentration
is lowered below a certain predetermined value and repeating the
addition operations in a certain time interval, whereby the
concentration of the developing solution can automatically be
retained at a certain level.
In general, a developing solution for photocopying machines
consists essentially of a strengthening solution wherein a pigment
or fine carbon powder is dissolved in a solvent to form a
concentrated solution and of a solvent for diluting said
strengthening solution. The concentration of the developing
solution varies with use and in particular where dark figure
portions are abundant in the copy, the carbon or pigment content is
rapidly transferred or removed and thus the developing solution is
quickly diluted.
In conventional photocopying machines, the concentration of the
developing solution has been adjusted by manual operation of a
valve to drop concentrated solution therein, but such operation has
the disadvantages that correct maintenance of the concentration is
quite difficult and the hands of the operator are liable to be
stained with the concentrated developing solution.
According to the present invention, there is provided an
automatically operating arrangement in which the above
disadvantages are completely eliminated by combining a simple
electronic circuit, an electric valve and photoelectric sensing
means thereby enabling an appropriate concentration of the
developing solution to be automatically maintained.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a perspective view of an electronic photocopying machine
according to the present invention;
FIG. 2 is a side sectional view illustrating the essential parts of
said electronic photocopying machine of the present invention;
FIG. 3 is a side sectional view of a lens exchange device for said
electronic photocopying machine;
FIG. 4 is an oblique view of a sensitive paper feeding device;
FIG. 5 is a partial plan of a belt for a sensitive paper feeding
belt;
FIG. 6 is a side sectional view thereof;
FIG. 7 is a side sectional view of said sensitive paper feeding
device;
FIG. 8 is an oblique view of a sensitive paper separating hook;
FIG. 9 is a diagram showing the displacement of focal distance due
to the movement of lenses;
FIG. 10 is a partial perspective view showing a practical example
of FIG. 9;
FIG. 11 is an exploded fragmentary view in perspective of a
stopping device for lens fixtures;
FIG. 12 is a diagram of an electric circuit for driving and
controlling the electronic photocopying machine according to FIGS..
1 and 2;
FIG. 13 and FIG. 14 are respectively an electric circuit diagram
and perspective view of a dial counter for sheet numbers of
sensitive paper;
FIG. 15 is a partial perspective view of an electrification device
and an exposure frame in said electronic photocopying machine;
FIG. 16 is a fragmentary and exploded perspective view showing a
roller-supporting position;
FIG. 17 is a perspective view of said exposure frame and of an
exposure frame body accompanied with driving rollers;
FIG. 18 is an explanatory sectional view of an intermittent
sensitive paper feeding device for said electronic photocopying
machine;
FIG. 19 is a diagrammatic illustration of a system adjusting the
concentration of the developing solution;
FIG. 20 is an enlarged sectional view showing the valve at the
bottom of the vessel containing concentrated developing
solution;
FIGS. 21a, 21b and 21c are diagrammatic illustrations showing
respective concentration detecting parts of the concentration
adjusting device; and
FIG. 22 is an electronic wiring circuit for the concentration
adjusting device.
DETAILED DESCRIPTION
In FIGS. 1 and 2 is shown a general construction of the electronic
photocopying machine of the present invention and therein 1 denotes
an outer casing and 2 denotes a glass plate on which an original 3
is loaded; 4 denotes a soft plate to push down said original; 5 and
6 denote illuminating lamps for the original; 7 is an illuminating
box with a cooling fan for illuminating the surface of the original
with the aid of the lamps; 8 is a reflecting plate to reflect the
image from the original; 9 denotes a projecting lens means; 10
denotes a transparent focusing glass for making the sensitive paper
20 even. A clearance of approximately 1 mm is provided between said
transparent focusing glass and plane rear plate 10', and said
sensitive paper is fed into said clearance.
Two projecting lenses 9, 9' are used as shown in FIG. 3 of which,
for instance, lens 9 is a projecting lens for equimultiple
photographing and lens 9' is a projecting lens for contraction
photographing. In this case, the equimultiple and contraction
photographings are performed by various lenses mentioned above, of
varying focal lenths. As illustrated in FIG. 3 and 11, a lens
fitting 19 is provided with a knob 13 which protrudes outside the
machine through a hole 14 formed in the outercasing and a lever
shank is provided on a pin 11, as a lens-exchanging means.
Furthermore, a stopping mechanism (see FIG. 11) comprising a ball
16, a spring 17 and a pushing screw 18 is provided on a front panel
12 of a photographing box 15. When either of the two lens comes to
the optical axis, the ball 16 enters a recess 38 of the lens
fitting member 19, said fitting member being thereby stopped. In
such a way, with even two or three lenses, similar operation can be
conducted. Further as in said embodiment of the present invention,
the distance between the original 3 and sensitive paper 20 may be
changed. The means therefor are shown in FIG. 9, wherein the glass
plate 2 on which the original is loaded and the lens 9 are placed
respectively at the position shown by solid lines for the
equimultiple photographing and the contraction photographing is
performed by displacing said glass plate 2 and said lens 9 to the
dotted line positions. This is easily understood from the
fundamental calculation regarding the optical system and the
carrying out means is shown in FIG. 10.
Namely, in FIG. 10, a frame 2' joined with the circumference of
glass plate 2 for loading the original 3 is formed with a plurality
of holes H.sub.1 - H.sub.3. Each middle hole H.sub.1 engages a pin
P.sub.1 provided in the outer casing 1 of the copying machine
proper, for the purpose of positioning while the other pairs of
holes H.sub.2 and H.sub.3 are spaced respectively by distances A
and B to engage P.sub.2 and P.sub.3 on the outer casing 1. If the
frame 2 is taken off the pins and turned around through 180.degree.
horizontally, and then if the frame is engaged with the pins again,
pin P.sub.1 is sufficiently long to fit with the hole H.sub.1. But
since pins P.sub.2, P.sub.3 can not be respectively inserted in
holes H.sub.2, H.sub.3, said frame is raised by the heights of pins
P.sub.2, P.sub.3. Accordingly, if the heights of pins P.sub.2,
P.sub.3 are assumed to be the length of the abovementioned objects
can be accomplished and the lens can be advanced by well-known
means, such as a helicod or like means.
In connection with FIG. 1, FIG. 2 and FIG. 4, the sensitive paper
20 of sheet formed and cut in regular sizes is piled up on the
upper portion of machine, with the sensitive surface facing
downward. It is pulled out, sheet by sheet, by paper feeding
rollers 25, when a print switch button 36 is pushed. In order to
prevent the sheets of sensitive paper 20 from being sent out more
than two sheets at a time, friction plates 21 made of sponge,
rubber or the like are used and guide plates 22, 23 and 24 which
prevent meandering of said sensitive paper are also used for
changing the advancing direction of the sensitive paper. Further,
the paper feeding rollers 25 are rotated through a transmission
gear comprising a motor 27, sprocket wheels 28, 29 pulleys 26 and
30, a chain 31, a belt 33 and a shaft 32, until the front end of
sensitive paper 20 reaches a microswitch 34 whereby said
microswitch is opened and motor 27 is stopped (see FIG. 12), so
that two sheets of sensitive paper are not transported. During this
time, a sheet of sensitive paper 20 is taken between rollers 41 and
41' and fed continuously between corona electrification device 37
to become sensitive to light and then fed to the exposure surface
through rollers 42 and 42'.
A movable contact of the other microswitch 35 provided in parallel
with the microswitch 34 is initially in contact with a terminal to
which a resistor R.sub.1, neon lamp Ne and resistor R.sub.3 are
connected, as illustrated in FIG. 12, and moves so as to contact
the other terminal to charge a condenser C.sub.1 through a
rectifier 39 when an actuator thereof is pushed by the front side
or edge of said sensitive paper 20 passing across the same.
However, the actuator of said microswitch returns to unactuated
position to return the movable contact to said initial position
when the rear side or edge of the sensitive paper is passed
completely across the actuator and thus the condenser C.sub.1
discharges charged current through the resistor R.sub.1, neon lamp
Ne and resistor R.sub.3 and illuminate the lamp Ne. Accordingly,
the collector current of a transistor TR is increased and as relay
RY.sub.1 is operated to close-circuit the contact point RY.sub.1 A,
relay RY.sub.2 is operated to change contact point RY.sub.2 A over
to contact point RY.sub.2 B. Therefore, the main motor 40 and
related rollers are all stopped, while the sensitive paper 20 is
stopped at exposure position and simultaneously the lamps 5 and 6
are lit and the exposure is commenced. However, the charge charged
into the condenser C.sub.1 is gradually discharged according to a
time constant as established by R.sub.1, R.sub.3, VR and C.sub.1,
the collector current of TR being thereby decreased and RY.sub.1
and RY.sub.2 being recovered after several seconds. In consequence,
illuminating lamps 5 and 6 are extinguished and again the main
motor 40 is rotated and the sensitive paper 20 is fed out of the
exposure frame. Further, a variable resistor VR is used for
adjusting the operational time for the timer.
In FIG. 15 showing construction details in the neighborhood of the
exposure frame, rollers on the side of sensitive film (opposite the
flat transparent plate 10, and also on the side of lenses) of
sensitive paper 20 are all driven rollers, and the bearings of all
other 41', 42', 43, 45 and so arranged as to be pushed to the
counter driving rollers by spring pressure slidably as shown in
FIG. 16. Namely, in FIG. 16 a bearing 92 slidable along a notched
groove of a holding plate 91 and a spindle 97 of driven roller 41'
is inserted in said bearing and a metallic stopper 93 is provided
for avoiding dropping-off of said bearing. A spring 94 is held with
two pins 95 to push down bearing 92. The abovementioned
construction is a mere example, and other equivalent constructions
may be as well used. Further, the driven roller 43 as illustrated
in FIG. 15 is pushed by one end of a lever 44' which is tensioned
by a spring 29 and pivoted on a pin 44 suitably secured to the
copying machine body and thus said driven roller always urged to a
driving roller 43'.
On the other hand, each of driving rollers 41, 42, 43' and 45'
possesses a sprocket wheel 46 respectively as shown in FIG. 15 and
is connected with chain 47 through sprocket 48 and idle pulley 49
and rotated by main motor 40 through electromagnetic clutch
40'.
As apparent from the foregoing descriptions, consideration will now
be given to the film surface side and rear surface side of
sensitive paper 20 separately. Between both sides, since there is
no power transmission mechanism on the roller surface excepting the
frictional transmission on said surface, said construction can be
incorporated with the film surface side and with rear surface side
respectively. Thus, the rear surface side can be alone separated,
opened and closed, and moreover when opened, all the driven rollers
can be stopped. Therefore, the sensitive paper 20 can be easily
taken out, or focusing can be performed easily. If, on the
contrary, the film surface side of sensitive paper 20 is operated
for driving the roller instead of as in the construction of the
present embodiment, it is very difficult to design a construction
wherein the said driven roller shaft does not project and it is
obvious that such a construction can not be realized. Further, when
both driving rollers and driven rollers are presented, the
situation will become even more difficult.
Further, as a means for feeding sensitive paper 20 in the
abovementioned copying machine, the belt conveyor shown in FIGS. 5
to 8 is recommended. More particularly, an endless belt 57 is
incorporated with or separately secured with a large number of
flexible sucking discs 58; said belt being hung over rollers 59 and
79 either of which rollers for instance, one of the rollers 59 is
set as the driving roller and opposed to a roller 10 which imparts
suction to the suctioning discs, while the other 79 is opposed to a
hook means 108 for separating sensitive paper from the sucking
discs. A pair of rollers 109 and 109' is provided at the near
downward portion to said hook so as to feed the sensitive paper. In
addition, when sensitive paper 20 is introduced in a space between
rollers 59 and 107, the sucker 58 of belt 57 will be compressed
with said two rollers and will be passed through said rollers with
said sensitive paper, while the interior air is forced out.
Therefore, the suckers 58 passing through said two rollers advances
with said sensitive paper being sucked thereagainst and the paper
thus approaches the stopping position for exposure. Then, the
exposure is completed with images of original figures being
projected onto the sensitive paper through lens 9 and again belt 57
proceeds accompanied by the sensitive paper. As it passes along the
curve of roller 79 the outside length becomes large and suckers 58
are deformed correspondingly. Sensitive paper can not correspond
thereto and air is lost due to the deformation. Automatically, the
sensitive paper is peeled off separately and said paper is guided
to feeding rollers 109 and 109' by the separating hook 108 which
serves also as a guiding member to proceed downward to the
following step.
According to the present embodiment since the sensitive paper is
fed between rollers together with flexible sucking discs
incorporated or separately provided in a transporting endless belt,
the sensitive paper cannot slide but is firmly and closely kept in
position due to the sucking action of many sucking discs. Moreover,
shadows from the previously employed clipping bars and hooks are
avoided and do not appear on the copying surface. Further high
priced and complicated means for vacuum suction purposes is not
required.
Next, FIG. 17 is a perspective view of an exposure frame and
driving rollers according to the present invention. All references
in FIG. 17 correspond to those of FIG. 2. 50 denotes the machine
bed of the present copying machine; 51 denotes a pair of supporting
brackets; 52 denotes a pin mounted on said supporting bracket, said
pin being engaged with holes 53 formed in the plate 98' and being
so composed as to rotate a driving system block as represented by
two point-chain lines, and when closed, a recess groove 56 of lever
55 is engaged with pin 54 secured to exposure frame body 98 thereby
retaining a clearance between the flat transparent plate 10 and
rear plate 10'. Furthermore, 60 denotes a developing vessel for
developing the sensitive paper 20 already exposed.
One of the features of the copying machine according to the present
invention lies in that a next sensitive paper 20 is drawn into an
exposure position, i.e. into clearance between the transparent
focusing glass 10 and rear plate 10' for commencing the next
exposure, while the sensitive paper 20 already exposed is
continuously pulled in the developing vessel 60 thereby providing a
continuous copying velocity capable of being abruptly
increased.
Generally, in the automatic copying machine, the sensitive paper is
usually fed at a predetermined velocity through all the steps
excepting the stationary period during said exposure stage. For
instance, in the electronic copying machine, the sensitive paper is
fed in order through all the steps from the feeding-in of sensitive
paper through charging, exposing and drying (fixing) or the like at
constant velocity excepting the exposure.
Furthermore, in order to manufacture a plurality of copies
continuously from the same manuscript (objects) each time the
sensitive paper is stopped, the distance between the sensitive
paper advanced during the time and that just stopped is extended
and it is reasonable that the copying velocity per minute is
decreased. During the steps of electrification, development, drying
and so forth, the velocity of movement is required to be rather
uniform or else in the finishing of the figures there occur
troubles such as uneveness in electrification and the finish of
figures, uneveness in the development and uneveness in drying all
of which damages the quality of the pictures.
An object of the present invention is to continuously effect the
copying operation at highest effeciency within the required
limitation of paper feeding velocity in the development and drying
stages by possibly shortening the distance between sheets of
sensitive paper during the exposure. In order to accomplish such as
object, according to the present invention, an intermittent feeding
device for sensitive paper as shown in FIG. 18 can be proposed. The
object or original 3 is put on the stand glass plate 2 so as to
contact images on the object to be copied with the plate 2. When
the surface of the object is illuminated bby a suitable light
source, the optical path from the object is bent by means of the
plane reflecting mirror 8 and the image on the object is projected
onto the sensitive paper 20 through the lens assembly 9 and the
flat transparent plate 10 and copies onto the sensitive paper which
is fed prior to the exposure in position between the flat
transparent plate 10 and the rear plate 10' located in parallel
with the transparent plate and closely thereto. Further, another
means, for instance, a plane rear plate 10' formed with a number of
small holes, without using the flat transparent plate 10, the air
existing between the sensitive paper and plane rear plate is
evacuated by a suctioning device (not illustrated) so that said
sensitive paper is sucked to the surface of said plane and back
plate and simultaneously transported. Furthermore, when the
distance from rollers 42 and 42', 45 and 45' are longer than thhe
sensitive paper, rollers 43 and 43' for transporting said sensitive
paper with only ear portions thereof being clamped are used. The
reference letters a - e show the sensitive papers occupying the
drying, developing position, a position between exposing and
developing positions, exposing and awaiting position,
respectively.
In the abovementioned construction, all the rollers driven by the
motor 40 are stopped, when the sensitive paper is fed into the
exposing position, by means of the microswitches 34, 35 and the
related mechanism as described hereinbefore, the lamps 5 and 6
(FIG. 2) illuminating to commence the exposure. When the circuit
recovers after an appropriate period of time has elapsed, by means
of a timer in the circuit, the abovementioned illuminating lamps
are extinguished, said rollers begin to rotate and the sensitive
paper after exposure is discharged by rollers 45 and 45'. When the
front side of the exposed sensitive paper abuts and presses the
actuators of microswitches 34', 35' at the lower end of the
exposing position, this actuates the microswitches so as to
commence the feeding of the next sensitive paper to the exposing
position through rollers 42 and 42'. On the other hand, the
preceding exposed sensitive paper is guided by a guide plate 61,
and introduced into a developing vessel 60 by rollers 62 and 62',
and developed by developing solution 64. After a squeezing out of
the excess amount of solution by rollers 63 and 63' , the developed
wet sensitive paper is transferred by a conveyor belt to a heater
82 to dry the same, and the paper is discharged from the machine.
The development vessel illustrated is a single bath type but a
two-or-more bath type vessel can, of course, be worked out
similarly. Moreover, any dry type developing means may be used for
the present copying machine in lieu of the wet one.
In the abovementioned construction, the features of this embodiment
of the present invention which are useful for shortening the
distance between each of the sensitive papers include that the
feeding velocity for the sensitive papers, i.e. circumferential
velocity of rollers 25, 41, 42, 43' and 45', is increased to
several times the feeding velocity for rollers subsequent to the
roller 62 and simultaneously the resulting deflection of the
sensitive paper is temporarily taken out of the regular passage to
avoid effect on the velocity of feeding sensitive paper for the
developing and drying (fixing) stages.
This will further be explained in connection with FIG. 18 wherein C
is the sennsitive paper which is entering the developing vessel 60
after the exposure finished, the front end of said sensitive paper
approaching the vessels from rollers 45, 45' to 62, 62' along the
shortest course. However, since the feeding velocity of rollers 45,
45' is higher than that of rollers 61, 62, the later half of the
sensitive paper forms a loop outside the passage as apparent in
FIG. 18 and the tail of the sensitive paper passing through rollers
45, 45' turns as shown and assumes an arc like shape as shown in
the thick dotted lines. Meanwhile, the next sensitive paper d is
drawn into the exposure position and it is arranged that c may pass
through rollers 62, 62' completely until the exposure is
finished.
As apparent from the foregoing operations, the continuous copying
capacity N in a fixed period of time is shown substantially as in
the following formula:
N =60 /S+W/.upsilon. + .tau.
wherein:
S: distance (cm) between the sensitive papers, respectively at
waiting and exposing positions
W: length of sensitive paper (cm)
.upsilon.: sensitive paper feeding velocity (cm/sec) until the
paper entering the developing vessel i.e. circumferential velocity
of rollers 25, 41, 41', 42, 42', 43, 43', 45, 45'
.tau.: exposure time.
The above-shown S.W. .tau. are constant according to each copying
machine, and can not be altered abruptly but .upsilon. can be
changed relatively easily.
As described above, since the capacity of copying machines is
limited according to the developing and fixing usually it is
limited to approximately 3cm/sec, while, on the contrary, according
to the present invention, the velocity can be increased to
approximately 10 cm/sec. The practical examples for both cases will
be described as follows:
Assuming that S = 9cm, W = 21cm (Japanese Standard Paper Sizes:
A4), and .tau. =4 sec, when .upsilon. = 3 cm/sec, N = 4.3
sheet/min; when .upsilon. = 10 cm/sec, N = 8.6 sheet/min. Namely,
the copying velocity can be doubled.
As ahead - running sensitive paper passes through rollers 62, 62'
in (S + W/.upsilon. + .tau.) seconds = 7 seconds, copying can be
contained without overlapping.
Next, the sensitive paper enters the developing vessel 60 as
described above. Driving rollers 62, 63 and driving pulley 77
possess sprocket wheel 73 respectively, and rotate by the
transmission mechanism of chain 76 through motor 72, sprocket wheel
75 and idle pulley 74; and a conveyor belt 81 is rotated by driving
pulley 77 and driven pulley 78. Furthermore, the developing vessel
60 is provided with a guide plate 65 for guiding passage of
sensitive paper and withh a developing electrode 66 adjacent the
sensitive plane. Sensitive paper is advanced through the clearance.
Further, as shown in FIG. 1, 67 denotes a jet pipe for developing
solution; 68 denotes a solution supplying pipe; 69 denotes a drain
hole; 70 denotes a liquid delivery pipe for discharging a liquid to
the developing tank. The surfaces of liquid-squeezing rollers 63
and 63'0 are cleaned by a cleaner 71. On the other hand, a dryer 80
is located at the middle of the conveyor belt 81, heat light rays
issued by a drying heater 82 are collected by a reflecting cap 83
to illuminate the dried surface and simultaneously heat
particularly between the bottom plate 84 and top plate 85 at high
temperature. Further, 86 denotes a fan for accelerating the drying;
87 denotes insulating plates for protecting the reflecting mirror 8
and lens 9 or the like from heat, and the sensitive papers
completely dried are gathered in a paper receiving member 89.
Further, 90 is a fan for dispersing the heat accumulated in the
upper portion outside the machine.
Referring now to FIG. 19, a suitable amount of developing solution
is always kept in a tank 201 and stirred therein with a stirrer
203. The developing solution is continuously pumped by a pump 204
through pipe 68 to developing vessel 60 and stored therein for
passage of the photosensitive paper only in a certain amount. The
remaining developing solution is removed from the developing vessel
60 and returned to the tank 201 through pipe 70. The stirrer 203
may be dispensed with and the tank 201 and developing vessel 60 may
be constructed as an integral member. A stregthening or
concentrated developing solution 209 is accommodated in an inverted
bottle 210 mounted on a lid 201' of the tank 201 and is supplied to
the developing solution in the tank 201 to increase the
concentration thereof, by pressing one end 212' of a lever 212 the
other end of which rotates about pivot 213 to press upwardly a
valve shaft 211 of a valve provided at the mouth of the bottle 210
to open the valve. Hitherto, the lever 212 has been manually
operated by an operator, but according to the present invention,
the lever 212 is automatically operated, as will be shown
hereinafter. The valve structure mounted on the mouth of the bottle
is generally known but an embodiment thereof which may be used in
the invention shall be explained by referring to FIG. 20, by way of
example. A threaded cap 220 of the bottle 210 comprises a packing
225 and is provided with a central opening 220' through which the
valve shaft 211 extends. The cap is supported by a frame like
member 221 secured to the central portion of the cap 220. On the
valve shaft 211, two valve elements 223 and 224 are fixedly mounted
in opposed relation and the valve shaft 211 is urged downward by a
spring 222. With such valve arrangement, the concentrated solution
in the bottle will be discharged by pressing the valve shaft toward
the inside of the bottle with the aid of lever 212, but if the
valve shaft is pressed further in the same direction the valve
element 223 will block the central bore 220' of the cap 220 to stop
the outflow. If the pressing of the valve shaft 211 is then
released, the discharge will again occur but is immediately
stopped, since the valve element is urged by the spring 222 and
returns to its initial position as shown in FIG. 20. A valve
structure, wherein the valve elements 223 is omitted, may of course
be employed for the device according to the present invention.
The present invention is characterized by further providing as
shown in FIG. 19, a means 214 for measuring the concentration of
the developing solution, an electronic circuit 215 and a valve
opening and closing solenoid or motor 216, thereby automatically
detecting and measuring the concentration of the developing
solution, adding concentrated solution to the developing solution,
and stopping the addition when the concentration reaches a
predetermined value, the addition being repeated and stopped
automatically at suitable and constant time intervals.
FIGS. 21a, 21b and 21c show embodiments of the concentration
measuring means. In all the embodimennts, light beam from a source
230 reaches a photoelectric element 231 through the developing
solution along a suitable light path.
FIG. 21a shows a light path from a lens 232 and reflecting mirrors
233 and 233', wherein the light beam reflected by the mirror 233
passes through a closed window 234 and reaches the mirror 233'
through another closed window 234' which is spaced from the window
234 by the distance d as shown, the light path passing through the
developing solution. FIGS. 21b and 21c show other light paths which
are respectively formed from optical fibers and optical material
having high refractive indices (n = 1.8 or more) so as to prevent
refractive scattering of the light beam in the developing
solution.
FIG. 22 shows an electronic circuit, wherein L and CdS represent
respectively a lamp as the light source and a photoelectric element
which correspond to the members 230 and 231 in FIGS. 21a - 21c. In
this circuit, the internal resistance of CdS and a variable
resistance R.sub.5 form a potential divider for a DC voltage stored
in a condenser C.sub.1, so that, in normal periods (the
concentration of the developing solution being at a desired level
and the amount of light beam reaching to CdS not being large), the
bias voltage of a transistor TR is kept at a lower value relative
to its base voltage. When the concentration of a developing
solution lowers, the potential at point e gradually raises to
increase the collector current of the transistor TR and then
actuate a relay RY.sub.1. Since a contact of switch SW.sub.3 will
move from its initial position as shown in FIG. 22 upon the
actuation of the relay RY.sub.1, the charge stored in condenser
C.sub.2 is discharged through a coil in a relay RY.sub.2 to actuate
switches SW.sub.1 and SW.sub.2 for keeping the relay RY.sub.1 in
its operational state. A movable contact of a switch SW.sub.4 will
move from its initial position as shown in FIG. 22 with the start
of discharge in the condenser C.sub.3 and is kept in its moved
position during the discharging period, so that a condenser C.sub.4
can discharge to actuate solenoid 216 for attracting the lever 212
which acts on the valve shaft 211 for discharging strengthening
solution. When the discharge of the condenser C.sub.3 is completed,
the switches SW.sub.1 and SW.sub.2 open, and the movable contact in
the switch SW.sub.4 returns to its initial position, as
respectively shown in FIG. 22 to interrupt the current flowing to
the solenoid 216. The feature of this circuit lies in that a time
delay defined by the condenser C.sub.3 and resistance r of the
relay RY.sub.2 is set for several to 10 seconds (this period is
called T), so that the above operation is repeated in required
times when the movable contact in the switch SW.sub.3 returns to
its initial position. This time delays is set to provide sufficient
mixing time in which the strengthening solution is sufficiently
stirred with the developing solution in the tank. If there is not
provided any time delay circuit, the concentration of the
developing solution where the strengthening solution has dropped is
too high at one place but at another place, particularly where the
photoelectric element CdS is arranged is low and thus the solenoid
continuously actuates to increase the concentration by introducing
the strengthening solution. If there is not provided any repeating
system, the device can not detect whether or not the concentration
reaches the predetermined level with one supplying operation of the
strengthening solution.
The solenoid may be a simple plunger type as illustrated in FIG.
22, but it may also be a combination of a gear motor and a cam.
The concentration control device has the advantage that the
concentration of the developing solution can automatically be
controlled and there is no fear that the concentration of the
developing solution can become too high. The operation is easy and
stable, and constant concentration solution can be fed to the
developing portion.
FIGS. 13 and 14 represent a sheet number dial counting device which
records the number of sheets copied wherein 110 denotes a rotary
solenoid, 111 denotes a rectifier and 112 denotes a sheet number
dial. Another exposure device may also be made so as to disconnect
the feeding rollers within the exposure range of sensitive paper
sucked to the casing through action of a solenoid. Moreover, in an
optical device the projection is made on the surface of said object
through a lens system, a transparent flexible belt and cloth or
rubber or the like flexible belt are provided in contact with each
other, and said contact surface is made to be coincident with the
focal plane of said optical device and the transparent belt is
arranged at the lens side and sensitive paper is put between both
belts and exposed by projection through the transparent belt.
Simultaneously the transportion of said sensitive paper is stopped
by the interlocking of those belts. Further, as another embodiment
of the sensitve paper feeding devices, a transport member having an
insulating resistor is used to attract and transfer the sensitive
paper electrostatically.
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