U.S. patent application number 12/206969 was filed with the patent office on 2009-06-04 for option-type paper feeding device.
This patent application is currently assigned to Tohoku Ricoh Co., Ltd.. Invention is credited to Mituru TAKAHASHI.
Application Number | 20090140487 12/206969 |
Document ID | / |
Family ID | 40674935 |
Filed Date | 2009-06-04 |
United States Patent
Application |
20090140487 |
Kind Code |
A1 |
TAKAHASHI; Mituru |
June 4, 2009 |
OPTION-TYPE PAPER FEEDING DEVICE
Abstract
The invention provides an option-type paper feeding device that
can contribute to enhancing printing operation efficiency while
taking advantage of variable printing speed in a printing
apparatus. A high-volume paper feeding device includes: a paper
stacking section; a paper feeding mechanism; and an intermediate
transport section connected to a paper feeding section of a
printing apparatus such as a stencil printing apparatus. The
intermediate transport section includes: a first paper transport
means; and a second paper transport means provided downstream of
the first paper transport means, and an inkjet printing section is
provided above the first paper transport means. The transport speed
of the first paper transport means is fixed to a speed suitable for
printing by the inkjet printing section, while the transport speed
of the second paper transport means is variable. The transport
speed of the second paper transport means is adjusted by control
means (not shown in drawings) in accordance with the printing speed
of a printing apparatus connected to the high-volume paper feeding
device.
Inventors: |
TAKAHASHI; Mituru; (Miyagi,
JP) |
Correspondence
Address: |
OBLON, SPIVAK, MCCLELLAND MAIER & NEUSTADT, P.C.
1940 DUKE STREET
ALEXANDRIA
VA
22314
US
|
Assignee: |
Tohoku Ricoh Co., Ltd.
Shibata-machi
JP
|
Family ID: |
40674935 |
Appl. No.: |
12/206969 |
Filed: |
September 9, 2008 |
Current U.S.
Class: |
271/10.01 |
Current CPC
Class: |
B41J 13/0018 20130101;
B65H 3/44 20130101; G03G 2215/00945 20130101; B65H 7/20 20130101;
B41L 13/06 20130101; G03G 2215/00599 20130101; B65H 2404/2691
20130101; G03G 15/6558 20130101; B65H 2513/10 20130101; B65H
2801/18 20130101; B65H 5/34 20130101; B65H 2801/21 20130101; B41J
11/007 20130101; B65H 5/021 20130101; B65H 2513/10 20130101; B65H
2220/02 20130101 |
Class at
Publication: |
271/10.01 |
International
Class: |
B65H 5/00 20060101
B65H005/00 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 3, 2007 |
JP |
2007-312610 |
Claims
1. An option-type paper feeding device, comprising: a paper
stacking section; a paper feeding mechanism for separating and
feeding, sheet by sheet, paper from the paper stacking section; an
intermediate transport section, arbitrarily connectable to a paper
feeding section of a printing apparatus for printing in use of a
plate, for transporting the paper fed by said paper feeding
mechanism towards the paper feeding section of said printing
apparatus; and an inkjet printing section provided in the
intermediate transport section, wherein said intermediate transport
section comprises first paper transport means provided facing said
inkjet printing section, and second paper transport means provided
downstream in a transport direction of the first paper transport
means, and a transport speed of said first paper transport means is
fixed to a substantially constant speed, and a transport speed of
said second paper transport means is variable.
2. The option-type paper feeding device according to claim 1,
further comprising control means for, on the basis of printing
speed information from said printing apparatus, adjusting the
transport speed of said second paper transport means so as to match
said printing speed, when said option-type paper feeding device is
communicably connected to said printing apparatus.
3. The option-type paper feeding device according to claim 1,
wherein said paper stacking section is capable of stacking thereon
a larger amount of paper than the paper feeding section of said
printing apparatus.
4. The option-type paper feeding device according to claim 1,
wherein at least said first paper transport means, among said first
paper transport means and said second paper transport means, has a
structure in which paper is suctioned and thereby transported by
electrostatic forces or by air negative pressure.
5. The option-type paper feeding device according to claim 1,
wherein the option-type paper feeding device can be used as an
inkjet printer by being directly connectable to a paper discharge
device, without said printing apparatus being interposed
therebetween.
6. The option-type paper feeding device according to claim 5,
wherein printing by said inkjet printing section can be stopped on
the basis of information from said paper discharge device, when
said option-type paper feeding device is communicably connected to
said paper discharge device.
7. The option-type paper feeding device according to claim 5,
further comprising control means for temporarily storing print data
in a memory, and for enabling supplementary printing by said inkjet
printing section through reading of the stored data.
8. The option-type paper feeding device according to claim 1,
further comprising cleaning means for cleaning an ink head of said
inkjet printing section, said cleaning means being operated on the
basis of a cleaning signal.
9. The option-type paper feeding device according to claim 1,
further comprising a press roller abutting an end of said first
paper transport means on an upstream side of the transport
direction, for pressing the paper.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a paper feeding device for
separating and feeding, sheet by sheet, stacked paper as a
sheet-like recording medium, more particularly, to an option-type
paper feeding device, the device itself having an inkjet printing
function and being structured as a hybrid printing system by being
suitably connected to, for instance, a stencil printing
apparatus.
[0003] 2. Description of the Related Art
[0004] Stencil printing apparatuses afford high-speed low-cost
printing, but can print only one color per drum. In color printing,
therefore, it becomes necessary to carry out superposed printing by
preparing a plurality of drums (four or more in full-color
printing), or to arrange such plural drums in one device.
Superposed printing requires time, while simultaneous four-color
printing involves highly costly constructions, which are therefore
not realized.
[0005] Stencil printing uses master plates, and hence has been
unsuitable for printing of changeable data in, for instance, page
printing, address printing and the like. Common portions have
therefore come to be stencil-printed, after which variable portions
are printed using a printer or the like, but this approach cannot
avoid the hassle and time expense involved.
[0006] For instance, Japanese Patent Application Laid-open Nos.
2002-137514 and 2002-137515 disclose a hybrid stencil printing
apparatus, comprising a stencil printing section and an inkjet
printing section that is different from the stencil printing
section, the hybrid stencil printing apparatus being capable of
performing color printing in one single paper run. To counter the
influence of the printing speed difference between the stencil
printing section and the inkjet printing section, a transport
stretch that is longer than the largest paper size is provided
between the two printing sections. However, providing a stencil
printing section and an inkjet printing section in one apparatus is
problematic in that, for instance, the resulting hybrid printing
system cannot be built using an already-existing stencil printing
apparatus, and in that the hybrid stencil printing apparatus
requires troublesome maintenance in terms of, for instance, inkjet
head cleaning and replacement.
[0007] Moreover, Japanese Patent Application Laid-open No.
2002-60072 discloses a hybrid image forming apparatus in which a
post-processing device, comprising an inkjet recording medium
device, is connected to the body of the image forming apparatus,
and in which an electrophotographic image forming section is
constructively separated from an inkjet printing section.
[0008] Also, Japanese Patent Application Laid-open No. 2006-76043
discloses a hybrid stencil printing apparatus in which an inkjet
printing section is provided in a unit exposed outside the
apparatus.
[0009] Japanese Patent Application Laid-open No. 2005-41631 (US
2005/0017430) discloses a hybrid stencil printing apparatus in
which a high-volume paper feeding unit, having an inkjet printing
section, is connected to a stencil printing apparatus. This hybrid
stencil printing apparatus allows constructing a hybrid printing
system using an already-existing stencil printing apparatus, and
enables fast and high-volume color printing that is compatible with
variable data. As a further advantage, maintenance of the inkjet
heads is straightforward.
[0010] The transport speed in the printing section of inkjet
printing devices is ordinarily constant. Adjusting and controlling
the ink discharge rate becomes thus complex when the transport
speed is variable. When constructing a hybrid printing system
(hybrid stencil printing apparatus or the like) in which an
option-type paper feeding device, having an inkjet printing
section, is connected to a printing apparatus such as a stencil
printing apparatus or the like, therefore, the transport speed
(printing speed) has to be matched to the transport speed of the
inkjet printing section, and thus the option-type paper feeding
device cannot be connected to a printing apparatus with which
transport speed is not matched.
[0011] Printing speed can be arbitrarily set in the stencil
printing apparatus, but in the case of conventional option-type
paper feeding devices having an inkjet printing section, the
printing speed is matched to that of the paper feeding device, and
hence printing can only be carried out at the printing speed of the
paper feeding device. It becomes thus impossible to reap the
benefits of a printing apparatus having multiple printing
speeds.
SUMMARY OF THE INVENTION
[0012] It is an object of the present invention to provide an
option-type paper feeding device that can contribute to enhancing
printing operation efficiency while taking advantage of variable
printing speed in a printing apparatus.
[0013] In an aspect of the present invention, an option-type paper
feeding device comprises a paper stacking section; a paper feeding
mechanism for separating and feeding, sheet by sheet, paper from
the paper stacking section; an intermediate transport section,
arbitrarily connectable to a paper feeding section of a printing
apparatus for printing in use of a plate, for transporting the
paper fed by the paper feeding mechanism towards the paper feeding
section of the printing apparatus; and an inkjet printing section
provided in the intermediate transport section. The intermediate
transport section comprises a first paper transport device provided
facing the inkjet printing section, and a second paper transport
device provided downstream in a transport direction of the first
paper transport device, and a transport speed of the first paper
transport device is fixed to a substantially constant speed, and a
transport speed of the second paper transport device is
variable.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The above and other objects, features and advantages of the
present invention will become more apparent from the following
detailed description taken with the accompanying drawings in
which:
[0015] FIG. 1 is a front-view diagram illustrating the schematic
constitution of a high-volume paper feeding device as an
option-type paper feeding device according to a first embodiment of
the present invention;
[0016] FIG. 2 is a diagram illustrating the schematic constitution
of an intermediate transport section of the high-volume paper
feeding device;
[0017] FIG. 3 is a block diagram illustrating the configuration of
a control system of the high-volume paper feeding device;
[0018] FIG. 4 is a schematic diagram illustrating the flow of ink
from an ink bottle to a waste liquid tank;
[0019] FIG. 5 is a front-view diagram illustrating the schematic
constitution of a hybrid stencil printing system in which a
high-volume paper feeding device and a high-volume paper discharge
device are connected to a stencil printing apparatus;
[0020] FIG. 6 is a front-view diagram illustrating the schematic
constitution of an inkjet printer according to a second embodiment
of the present invention, in which a high-volume paper feeding
device and a high-volume paper discharge device are connected
together;
[0021] FIG. 7 is a front-view diagram illustrating the schematic
constitution of a stencil printing apparatus according to the
present invention;
[0022] FIG. 8 is a block diagram illustrating the configuration of
a control system of the stencil printing apparatus; and
[0023] FIG. 9 is a perspective-view diagram illustrating the
constitution of a characterizing portion of an operation panel of
the stencil printing apparatus.
DESCRIPTION OF THE PREFERRED EMBODIMENT(s)
[0024] Embodiments of the present invention are explained below
with reference to accompanying drawings.
[0025] A first embodiment of the present invention will be
explained first based on FIGS. 1 to 5.
[0026] As illustrated in FIGS. 1 and 2, a high-volume paper feeding
device 200, as an option-type printing device, comprises for
instance a paper stacking section 201 on which printing paper can
be stacked in larger amounts than in sheet feeding trays or paper
feeding trays that are provided, as standard equipment, in printing
apparatuses such as stencil printing apparatuses or the like; a
paper feeding mechanism 202 for separating and feeding, sheet by
sheet, paper 166 from the paper stacking section 201; and an
intermediate transport section 203 for transporting the paper 166
fed by the paper feeding mechanism 202 towards a paper feeding tray
of a paper feeding section of a below-described stencil printing
apparatus.
[0027] The intermediate transport section 203 comprises an inkjet
printing section 204; a first paper transport means 205 provided
below the inkjet printing section 204, extending substantially
horizontally facing the inkjet printing section 204; and a second
paper transport means 206 provided downstream in the transport
direction of the first paper transport means 205.
[0028] The paper 166 is stacked on a paper feeding tray 162 of the
paper stacking section 201. The paper feeding tray 162, having
paper stacked thereon, is moved up and down, between a lower-limit
position and an upper-limit position, by a paper feeding tray
raising and lowering mechanism not shown. In FIG. 1, the reference
numeral 160 denotes a bottom plate, the reference numeral 161 a
paper size detection sensor for detecting paper size in the paper
feeding direction, and the reference numeral 163 a side fence. A
sensor, not shown, is provided also for detecting paper size in the
paper width direction, which is perpendicular to the paper feeding
direction.
[0029] The paper feeding mechanism 202 comprises, for instance, a
paper feeding roller 164a, a separation roller 164b, a separation
pad 165 and a stepping motor not shown. When the paper feeding tray
162, with paper stacked thereon, is raised by the above-described
paper feeding tray raising and lowering mechanism from a stop
position to an upper-limit position, the uppermost sheet of the
paper 166 on the paper feeding tray 162, which has stopped at the
upper-limit portion, is separated and transported by the separation
roller 164b and the paper feeding roller 164a that rotate through
the action of the above-described stepping motor, and is
transported to the first paper transport means 205.
[0030] Four line-type inkjet heads for a respective color are
disposed in the inkjet printing section 204. Dedicated heads of
four colors including Y (yellow) 42a, M (magenta) 42b, C (cyan) 42c
and Bk (black) 42d supply inks of respective colors to the inkjet
printer head.
[0031] In the high-volume paper feeding device 200 there are
disposed dedicated ink bottles of four colors including an ink
bottle Y (yellow) 41a, an ink bottle M (magenta) 41b, an ink bottle
C (cyan) 41c and an ink bottle Bk (black) 41d.
[0032] As illustrated in FIG. 3, an ink pump 207 is disposed in
each ink bottle. Ink is supplied to each inkjet printer head on the
basis of signals from a control means 208 that controls the
operation of the high-volume paper feeding device 200. The control
means 208 is a microcomputer having, for instance, a CPU, a ROM, a
RAM and an I/O interface.
[0033] In each ink bottle there is provided an ink residual amount
detection sensor 209, as an ink residual amount detection means
that outputs a residual ink amount signal to the control means 208.
On the basis of this signal, an operation panel 103 of the stencil
printing apparatus 300 illustrated in FIG. 9 can display the
residual amount of ink. As illustrated in FIG. 3, the residual
amount of ink can also be displayed on an operation panel 212 of
the high-volume paper feeding device 200.
[0034] Waste liquid generated during cleaning of the inkjet printer
heads is collected in a waste liquid tank 44 via waste liquid pipes
40a, 40b, 40c, 40d, as illustrated in FIG. 4. A waste ink
full-state detection sensor 210, provided in the waste liquid tank
44, outputs a full-state state signal to the control means 208. On
the basis of this signal, the waste liquid full-state can be
displayed on the operation panel 103. As illustrated in FIG. 3, the
waste liquid full-state can also be displayed on the operation
panel 212 of the high-volume paper feeding device 200.
[0035] The first paper transport means 205 comprises, for instance,
a driving roller 43a, a driven roller 43b, an endless belt 43c as a
paper transport member and a suction fan 46a. The paper 166
transported from the separation roller 164b is sucked, through air
negative pressure, is transported, and is delivered to the second
paper transport means 206 on the downstream side. The transport
speed of the first paper transport means 205 is fixed at a
predefined speed that is suitable for printing in the inkjet
printing section 204.
[0036] The second paper transport means 206 comprises, for
instance, a driving roller 43d, a driven roller 43e, an endless
belt 43f as a paper transport member and a suction fan 46b. In the
second paper transport means 206, the paper 166 transported from
the first paper transport means 205 is suctioned, through air
negative pressure, and is suction-transported up to an end position
of the intermediate transport section 203.
[0037] The transport speed of the second paper transport means 206
is variable (multi-speed). The control means 208, having obtained
printing speed information of a stencil printing apparatus 300 to
be described later from a control means 129 of the stencil printing
apparatus 300, sets the transport speed of the second paper
transport means 206 to an adequate transport speed. That is, the
transport speed of the second paper transport means 206 can vary in
accordance with the speed of a paper feeding roller and/or a resist
roller pair of the stencil printing apparatus 300. The second paper
transport means 206 has a speed conversion function between the
high-volume paper feeding device 200 and the stencil printing
apparatus 300.
[0038] Speed adjustment is carried out by controlling the rotation
speed of a driving motor 211, as a driving source, that drives the
driving roller 43d, as illustrated in FIG. 3.
[0039] The control means 129 of the stencil printing apparatus 300
controls the driving motor 211 via the control means 208.
[0040] As illustrated in FIGS. 1 and 2, a press roller 47, for
pressing the paper, is provided above the driven roller 43b, on the
upstream end, in the transport direction, of the first paper
transport means 205. The press roller 47 presses the paper against
the endless belt 43c.
[0041] As described above, the uppermost sheets of the paper 166
stacked on the paper feeding tray 162 are separated and
transported, sheet by sheet, by the paper feeding roller 164a and
the separation roller 164b. During paper transport in the first
paper transport means 205, however, the press roller 47 may be
pressed, while the paper 166 is separated and transported from the
paper feeding mechanism 202. Thereby, paper transport and inkjet
printing can be carried out simultaneously, and images can be
printed without image shift.
[0042] Misregistration between paper and images occurs when the
separation and transport speed of the paper feeding mechanism 202
and the paper transport speed of the first paper transport means
205 are not matched. To match the speeds, one of the speeds must be
matched to the other. Even if roller diameters, endless belt
thickness, working speed of the stepping motor and so forth are all
matched, there remain variations in machining precision as regards
roller diameters, endless belt thickness and the like. As a result,
rotation by the stepping motor may give rise to differences in the
respective transport speeds.
[0043] To address this problem, high-precision matching between
paper transport timings and inkjet printing timings is realized by
pressing the press roller 47 while the paper 166 is separated and
transported from the paper feeding mechanism 202, in such a manner
that there occurs no paper positional offset, by reliably
suction-transporting the paper at the transport speed of the first
paper transport means 205.
[0044] As shown in FIG. 5, the leading end of the intermediate
transport section 203 of the high-volume paper feeding device 200
is inserted into, and connected to, a paper feeding section 301 of
the stencil printing apparatus 300, as a printing apparatus for
printing using a plate. Herein, the paper detection sensor and so
forth of the paper feeding section 301 of the stencil printing
apparatus 300 are disabled by being blocked by the intermediate
transport section 203. Thus, the high-volume paper feeding device
200 takes over the function of the paper feeding section 301.
[0045] Needless to say, when the stencil printing apparatus 300 and
the high-volume paper feeding device 200 are electrically connected
(when the control means 129 and the control means 208 are connected
so as to be capable of communicating with each other), paper
feeding is controlled by the high-volume paper feeding device
200.
[0046] Aside from the paper feeding section 301, paper can also be
fed by providing a dedicated connection port (paper feeding
section), for connection with to high-volume paper feeding device
200, in the stencil printing apparatus 300. The constitution and
printing operation in the stencil printing apparatus 300 are
explained in detail further on.
[0047] In FIG. 5, the reference numeral 400 denotes a high-volume
paper discharge device, as a paper discharge device. The
high-volume paper feeding device 200, the stencil printing
apparatus 300 and the high-volume paper discharge device 400 are
mechanically and electrically connected to make up a hybrid stencil
printing system capable of printing in different printing modes
(stencil printing plus inkjet printing).
[0048] Upon reception of a paper feeding start signal from the
control means 129 of the stencil printing apparatus 300, a paper
presence detection sensor, not shown, of the paper feeding tray 162
of the high-volume paper feeding device 200 detects whether there
is stacked paper or not. If there is stacked paper, the paper
feeding tray 162, with paper stacked thereon, is raised by a paper
feeding tray raising and lowering mechanism, not shown, from a stop
position to an upper-limit position, the paper feeding tray 162
stopping then at the upper-limit position.
[0049] The uppermost sheets of the stacked paper 166 are separated,
one by one, by the paper feeding roller 164a and the separation
roller 164b, and are transported to the first paper transport means
205. The first paper transport means 205 maintains, with high
precision, the distance between the paper 166 and each inkjet
printer head, while transporting the paper 166 in a substantially
horizontal direction, during which predetermined printing by the
inkjet printing section 204 is carried out on the paper 166. That
is, printing by the inkjet printing section 204 is carried out
before feeding the paper to the stencil printing apparatus 300.
[0050] As a result, variable data portions can be printed by the
inkjet printing section 204, while common portions can be printed
by the stencil printing apparatus 300.
[0051] Suction transport allows herein the inkjet printing section
204 to perform paper transport and inkjet printing at given
timings, whereby images can be printed without image shift.
Although suction transport by air negative pressure is employed in
this case, electrostatic adhesion can also be used.
[0052] The inkjet printing section 204 may be a monochrome one, but
in the present embodiment inkjet printer heads for respective
colors are disposed in the inkjet printing section 204, in such a
manner that the latter is capable of full color printing.
[0053] Since the inkjet printing section 204 is thus capable of
full color printing, the high-volume paper feeding device 200
itself can function as an independent image forming apparatus.
[0054] As illustrated in FIG. 3, the high-volume paper feeding
device 200 has a cleaning means 213 for cleaning the various inkjet
printer heads of the inkjet printing section 204. The cleaning
operation of the inkjet heads in the inkjet printing section 204 of
the high-volume paper feeding device 200 is carried out in response
to an instruction from the control means 129 of the stencil
printing apparatus 300 or from the control means 208 of the
high-volume paper feeding device 200.
[0055] During mass printing, the cleaning operation can be carried
out depending on the number of print sheets, or during a temporary
printing stop, as a countermeasure against nozzle clogging caused
by paper dust during continuous printing.
[0056] A second embodiment is explained next on the basis of FIG.
6.
[0057] Elements identical to those of the first embodiment above
are denoted with identical reference numerals. Unless otherwise
necessary, features and functions already explained will be omitted
in the explanation, which will focus only on relevant portions.
[0058] In the second embodiment, the high-volume paper feeding
device 200 is not connected to the stencil printing apparatus 300,
but directly to the high-volume paper discharge device 400, to make
up thereby an inkjet printer.
[0059] The high-volume paper discharge device 400 may be an offline
paper discharge device in which a paper discharge tray 73 is
lowered for a given time when an upper-limit detection sensor, not
shown, detects a paper discharge upper limit on the paper discharge
tray 73. The paper discharge tray 73 is lowered down to a lower
limit position detected by a detection sensor not shown.
[0060] The paper, having been printed in full color printing
(inkjet printing) by the high-volume paper feeding device 200, is
transported to the high-volume paper discharge device 400 where it
is stacked on the paper discharge tray 73. In FIG. 6, the reference
numeral 71 denotes an upper plate, 70 a bottom plate, 72 an end
fence and 74 a side fence of the device body.
[0061] When the high-volume paper feeding device 200 and the
high-volume paper discharge device 400 are connected so as to be
capable of communicating with each other, the downward movement of
the paper discharge tray 73 is discontinued upon reaching the
lower-limit position, whereupon a signal indicating that the paper
discharge tray is full is sent to the control means 208 of the
high-volume paper feeding device 200. Upon reception of the signal
indicating that the paper discharge tray is full, the control means
208 of the high-volume paper feeding device 200 displays, on the
operation panel 212, that the paper discharge tray is full.
[0062] The high-volume paper discharge device 400 comprises a
transport jam detection sensor not shown. Upon detecting a paper
transport jam, the transport jam detection sensor sends a transport
jam signal to the high-volume paper feeding device 200. Upon
receiving the transport jam signal, the control means 208 displays
a paper jam notice on the operation panel 212, and stops the paper
feeding operation of the high-volume paper feeding device 200.
[0063] When the high-volume paper feeding device 200 is directly
connected to the high-volume paper discharge device 400, print data
inputted or transmitted by, for instance, a LAN, a removably disk
or the like is stored in an internal memory (ROM or the like) of
the control means 208. The print data can be printed later in the
high-volume paper feeding device 200. During printing, data can be
used for printing by being read from the internal memory in the
control means 208.
[0064] By setting a print sheet count and pressing a print key in
the operation panel 212, thus, data read out of the internal memory
in the control means 208 can be additionally printed in the
high-volume paper feeding device 200 after printing of a set number
of print sheets of transmitted or inputted print data.
[0065] The constitution and printing operation of the stencil
printing apparatus 300 illustrated in the first embodiment will be
explained next with reference to FIGS. 7 to 9.
[0066] As illustrated in FIG. 7, the stencil printing apparatus 300
comprises, for instance, a printing section 15, a platemaking
section 40, a paper feeding section 301, a plate discharging
section 80, a paper discharge section not shown, an image reading
section 50 and paper separation pawls 17.
[0067] The printing section 15, disposed substantially in the
center of the stencil printing apparatus 300, comprises a plate
cylinder 1 and a press roller 13. The plate cylinder 1 comprises
mainly a pair of end plates, not shown, rotatably supported on a
pivot shaft 16 that doubles as an ink supply pipe, a porous support
plate, not shown, wrapped around the outer peripheral face of the
end plates, and a mesh screen, not shown, wrapped around the outer
peripheral face of the porous support plate. The plate cylinder 1,
which is rotationally driven by plate cylinder driving means 121
(FIG. 8), is detachably mountable on the stencil printing apparatus
300.
[0068] The size of the plate cylinder 1 in the present embodiment
is such so as to allow obtaining printed products of a maximum A3
size during one-side printing. An ink supply means 18 is provided
inside the plate cylinder 1. The ink supply means 18 comprises, for
instance, the pivot shaft 16, an ink roller 3, a doctor roller 4
and so forth. The ink roller 3 is rotatably supported between side
plates, not shown, provided in the plate cylinder 1. The peripheral
face of the ink roller 3 is disposed in the vicinity of the inner
peripheral face of the plate cylinder 1. The ink roller 3 is
rotationally driven by driving means, not shown, in the same
direction as the plate cylinder 1.
[0069] The doctor roller 4 is also rotatably supported between the
above-described side plates. The peripheral face of the doctor
roller 4 is disposed in the vicinity of the peripheral face of the
ink roller 3. The doctor roller 4 is rotationally driven by driving
means, not shown, in an opposite direction to that of the plate
cylinder 1.
[0070] A plurality of small holes are opened in the pivot shaft 16,
such that the supplied ink accumulates in a space of wedge-like
cross section that forms in the vicinity of the ink roller 3 and
the doctor roller 4, to form a liquid pool.
[0071] A stage, not shown, that follows a plane along one
generatrix of the plate cylinder 1, is formed on the peripheral
face of the plate cylinder 1. A damper 6, for holding a leading end
of a master 2, is disposed on the outer peripheral face of the
plate cylinder 1. The damper 6, which rotates supported on a rotary
shaft 5 as a pivot shaft, is opened and closed by an opening and
closing means, not shown, when the plate cylinder 1 rotates up to a
predetermined position.
[0072] The press roller 13 is disposed below the plate cylinder 1.
The press roller 13, which comprises an elastic body such as rubber
or the like wrapped around a metal core, is disposed extending in
the axial direction of plate cylinder 1. Two ends of a core, not
shown, of the press roller 13 are rotatably supported by a pair of
arm members not shown.
[0073] The substantially L-shaped arm members are integrally formed
by way of a swinging shaft, not shown, mounted at a position in the
vicinity of bent parts of the arm members. The swinging shaft, not
shown, is swingably supported on the body of the stencil printing
apparatus 300.
[0074] The peripheral face of the press roller 13 occupies a
separated position from the peripheral face of the plate cylinder 1
when the protrusions of cam plates, not shown, abut cam followers
not shown. The peripheral face of the press roller 13 occupies a
pressure-contact position against the peripheral face of the plate
cylinder 1, on account of the urging force of a pressing spring,
not shown, when the abutting of either of the protrusions and the
cam follower, not shown, is released.
[0075] The platemaking section 40 is disposed at the right upper
portion of the stencil printing apparatus 300. The platemaking
section 40 comprises, for instance, a master holding member 41, a
platen roller 42, a thermal head 43, a cutting means 44, a master
stocking section 45, a tension roller pair 46 and a reversing
roller pair 48.
[0076] The master holding member 41 is provided at a pair of side
plates, not shown, of the platemaking section 40. The master
holding member 41 rotatably and detachably holds both ends of a
core of a master roll around which there is wrapped a master that
comprises a thermoplastic resin film bonded to a porous support. A
platen roller 42, not shown, provided on the left of the master
holding member 41, is rotatably supported on a side plate, not
shown, of the platemaking section 40. The platen roller 42 is
rotationally driven by a platemaking driving means 124 (FIG. 8)
that comprises a stepping motor not shown. The thermal head 43,
positioned below the platen roller 42 and comprising multiple
thermal elements, is mounted also on a side plate, not shown, of
the platemaking section 40. The surfaces of the thermal elements
are brought into pressure contact with the platen roller 42, on
account of the pressing force exerted by pressing means not
shown.
[0077] The thermal head 43 perforates the master, through thermal
fusion, by bringing the thermal elements into contact with the
surface of the thermoplastic resin film of the master, and by
selectively activating then heat generation in the thermal
elements. The cutting means 44 is disposed on the left of the
platen roller 42 and the thermal head 43.
[0078] The cutting means 44, not shown, comprises a fixed blade
fixedly provided on a frame, not shown, of the platemaking section
40, and a movable blade that is movably supported on the fixed
blade. The cutting means 44 has thus a well-known constitution for
cutting a master by rotationally moving the mobile blade relative
to the fixed blade.
[0079] The master stocking section 45 is disposed below the cutting
means 44, on the downstream direction of the master transport
direction. The interior of the master stocking section 45, as a
space in which the prepared master is stored for a while, is
partitioned by a plurality of plate members. A suction fan, not
shown, is arranged at the innermost portion of the master stocking
section 45. Driving of the suction fan generates a negative
pressure in the interior of the master stocking section 45, which
is an airtight space, whereby the prepared master, transported up
to the master stocking section 45, is stored in the innermost
portion of the latter.
[0080] The tension roller pair 46 is disposed at a position between
the cutting means 44 and the master stocking section 45. The
tension roller pair 46 comprises a driving roller and a driven
roller rotatably supported on respective side plates, not shown, of
the platemaking section 40. The peripheral face of the driven
roller is brought into pressure contact with the peripheral face of
the driving roller through the action of pressing means not shown.
The driving roller is rotationally driven by the platemaking
driving means 124, to clamp and transport the master.
[0081] The peripheral speed of the driving roller is set to be
slightly faster than the peripheral speed of the platen roller 42.
A torque limiter, not shown, is provided inside the driving roller.
The platen roller 42 and the tension roller pair 46 are configured
so as to apply a predetermined tension to the master.
[0082] The reversing roller pair 48, which is disposed on the
downstream side of the master transport direction in the master
stocking section 45, comprises a driving roller and a driven roller
rotatably supported on respective side plates, not shown, of the
platemaking section 40. The reversing roller pair 47 clamps and
transports the master by way of the driving roller, which is
rotationally driven by the platemaking driving means 124, and the
driven roller, which is disposed so as to be brought into pressure
contact with the driving roller by pressing means not shown.
[0083] A one-way clutch, not shown, is provided inside the driving
roller. A movable master guide plate, not shown, is disposed at a
position between the tension roller pair 46 and the reversing
roller pair 48. The movable master guide plate is swingably
supported on support members not shown. The top face of the movable
master guide plate can be selectively positioned, by way of a
solenoid not shown, between a transport position, at which the
movable master guide plate forms a master transport path, and a
retreat position at which the movable master guide plate does not
hamper insertion of the master into the master stocking section
45.
[0084] The paper feeding section 301 is disposed below the
platemaking section 40. The paper feeding section 301 comprises,
for instance, a paper feeding tray 60, a paper feeding roller 10a,
a separation roller 10b, a separation pad 11, a resist roller pair
12 and so forth. The paper feeding tray 60, onto the top face
whereof multiple paper sheets 100 can be stacked, is supported so
as to be movable up and down the body of the stencil printing
apparatus 300. The paper feeding tray 60 is raised and lowered by a
paper feeding driving means 125 (FIG. 8) that comprises raising and
lowering means.
[0085] On the top face of the paper feeding tray 60, where paper
100 of A3 size can be vertically set, there is provided a pair of
side fences 62 supported so as to be movable on the paper width
direction, which is perpendicular to the paper transport direction,
along rail members not shown.
[0086] Plural paper size detection sensors 61, for detecting the
size of the stacked paper 100, are provided at the free end side of
the paper feeding tray 60.
[0087] The paper feeding roller 10a, having on the surface thereof
a high friction resistance member, is disposed above the paper
feeding tray 60. The paper feeding roller 10a is rotatably
supported on a bracket, not shown, that is swingably supported on
the body of the stencil printing apparatus 300. The paper feeding
roller 10a is brought into pressure contact with the paper 100 at
the uppermost position of the paper feeding tray 60, with a
predetermined pressure contact force, when the paper feeding tray
60 is raised by a raising and lowering means not shown. The paper
feeding roller 10a is rotationally driven by a paper feeding
driving means not shown.
[0088] On the left of the paper feeding roller 10a there are
disposed the separation roller 10b and the separation pad 11
comprising, on the surface thereof, a high friction resistance
material. The separation roller 10b is drivingly connected to the
paper feeding roller 10a by way of a timing belt, such that when
the paper feeding roller 10a is rotationally driven, the separation
roller 10b is rotationally driven in synchrony with the paper
feeding roller 10a, in the same direction as the latter.
[0089] The separation pad 11 is brought into pressure contact with
the separation roller 10b on account of the urging force of an
urging means not shown. The resist roller pair 12 is disposed on
the left of the separation roller 10b and the separation pad 11.
The resist roller pair 12 comprises a driving roller 12b and a
driven roller 12a. The driving roller 12b rotates with a
predetermined timing, in synchrony with the plate cylinder 1, on
account of a rotational driving force from the plate cylinder
driving means 121 that is transmitted via a driving force
transmission means, not shown, comprising gears, cams or the like,
while the driven roller 12a is brought into pressure contact with
the driving roller 12b, as a result of which the paper 100 is fed
towards the printing section with a predetermined timing.
[0090] Paper feeding guide plates, for guiding the paper 100 that
is fed from the paper feeding section 301 to the printing section
15, are respectively disposed on the upstream and downstream sides
of the paper transport direction of the resist roller pair 12. The
paper feeding guide plates are fixed between side plates, not
shown, of the body of the stencil printing apparatus 300.
[0091] The plate discharging section 80 is disposed above and to
the left of the printing section 15. The plate discharging section
80 comprises, for instance, an upper plate discharging member 81, a
lower plate discharging member 82, a plate discharge box 83 and a
compression plate 84. The upper plate discharging member 81
comprises, for instance, a driving roller, a driven roller and an
endless belt. In the upper plate discharging member 81, the driving
roller is rotationally driven, in the clockwise direction of the
figure, by a plate discharging driving means 126 (FIG. 8), to move
thereby the endless belt.
[0092] The lower plate discharging member 82 comprises, for
instance, a driving roller, a driven roller and an endless belt. In
the lower plate discharging member 82, the driving roller is
rotationally driven, in the counterclockwise direction of the
figure, by the driving force of the plate discharging driving means
126, which rotationally drives the driving roller, the driving
force being transmitted to the driving roller via a driving force
transmission means, not shown, comprising gears, cams or the like.
The driving roller, thus rotationally driven, causes the endless
belt to move.
[0093] The lower plate discharging member 82 is movably supported
thanks to a moving means, not shown, comprised in the plate
discharging driving means 126. The lower plate discharging member
82 can occupy the position illustrated in the figure and a position
at which the endless belt, positioned on the outer peripheral face
of the driven roller, abuts the outer peripheral face of the plate
cylinder 1.
[0094] The plate discharge box 83, in which the used master is
stored, is removably provided in the body of the stencil printing
apparatus 300. The compression plate 84 for compressing, into the
plate discharge box 83, the used master that is transported by the
upper plate discharging member 81 and the lower plate discharging
member 82, is supported on the body of the stencil printing
apparatus 300 in such a way so as to be movable up and down. The
compression plate 84 is moved up and down by a raising and lowering
means, not shown, comprised in the plate discharging driving means
126.
[0095] A paper discharge section 20 is disposed below the plate
discharging section 80. The paper discharge section 20 comprises,
for instance, the paper separation pawls 17, a discharge paper
transport unit 21 and a discharge paper tray 70.
[0096] The paper separation pawls 17 are provided in the width
direction of the plate cylinder 1. The paper separation pawls 17
are integrally mounted on a pivot shaft that is swingably supported
on the body of the stencil printing apparatus 300. The paper
separation pawls 17 are swung by a pawl swinging means, not shown,
in such a manner that the ends of the paper separation pawls 17
selectively occupy a position, illustrated in the figure, in the
vicinity of the outer peripheral face of the plate cylinder 1, and
a position at which the ends of the paper separation pawls 17 are
separated from the outer peripheral face of the plate cylinder 1 in
order to avoid obstacles such as the damper 6 or the like.
[0097] The driving force from the plate cylinder driving means 121
(FIG. 8) is transmitted, via driving force transmission means, not
shown, to the pawl swinging means not shown, as a result of which
the paper separation pawls 17 are swung in synchrony with the
rotation of the plate cylinder 1.
[0098] The discharge paper transport unit 21, disposed below and to
the left of the paper separation pawls 17, comprises driving
rollers 25b, driven rollers 25a, endless belts 27 and a suction fan
26. The plural driving rollers 25b are mounted, with predetermined
spacings, on a pivot shaft, not shown, that is rotatably supported
on a unit side plate not shown. The driving rollers 25b are
rotationally driven in unison by a paper discharge driving means
127 (FIG. 8).
[0099] The driven rollers 25a are likewise mounted, with spacings
identical to those of the driving rollers 25b, on a pivot shaft,
not shown, that is rotatably supported on the unit side plate. The
endless belts 27 are wound around respective driving rollers 25b
and the corresponding driven rollers 25a. The suction fan 26 is
disposed below the driving rollers 26b, the driven rollers 25a and
the endless belts 27.
[0100] In the discharge paper transport unit 21, the printed paper
101 on the endless belts 27 is sucked by the suction force of the
suction fan 26, and is transported on account of the rotation of
the driving rollers 25b. The printed paper 101 transported by the
discharge paper transport unit 21 is stacked on the top face of the
discharge paper tray 70, which has one end fence 71 that is movable
in the paper transport direction, and a pair of side fences 72 that
are movable in the paper width direction.
[0101] The image reading section 50 is disposed above the stencil
printing apparatus 300. The image reading section 50 comprises, for
instance, a contact glass 52 on which a document is set; a pressure
plate 51 separably provided on the contact glass 52; reflecting
mirrors and a fluorescent lamp for scanning and reading document
images; a lens 53 for condensing a scanned document image; an image
sensor 54 such as a CCD or the like for processing the condensed
image; a plurality of document size detection sensors 55, for
detecting document size; and an image memory, not shown, for
storing the read image data. Reading of document images is
performed through the operation of a reading driving means 128 not
shown (refer to FIG. 8) As illustrated in FIG. 7, a dog 29 is
mounted on the outer face of an end plate, not shown, comprised in
the plate cylinder 1. A home position sensor 28 is mounted on the
body of the stencil printing apparatus 300, in the vicinity of the
periphery of the plate cylinder 1. When the plate cylinder 1
occupies a position where the clamper 6 stands opposite the press
roller 13, the home position sensor 28 detects the dog 29, and
sends a corresponding signal to the control means 129.
[0102] FIG. 9 illustrates the operation panel of the stencil
printing apparatus 300. In the figure, the top face of the
operation panel 103 provided in the upper front face of the stencil
printing apparatus 300 comprises, for instance, a platemaking start
key 104, a print start key 105, a test print key 106, a consecutive
mode key 107, a clear/stop key 108, a numerical keypad 109, an
enter key 110, a program key 111, a mode clear key 112, a printing
speed setting key 113, four direction keys 114, a paper size
setting key 115, a paper thickness setting key 116, a display
device 119 comprising a 7-segment LED, and a display device 120
comprising an LCD.
[0103] The platemaking start key 104 is pressed to launch the
platemaking operation in the stencil printing apparatus 300. When
the platemaking start key 104 is pressed, the platemaking operation
is carried out after plate discharge and document reading have been
performed. A plate fixing operation is carried out thereafter,
whereupon the stencil printing apparatus 300 is brought to print
standby.
[0104] The print start key 105 is pressed to launch the printing
operation in the stencil printing apparatus 300. When the stencil
printing apparatus 300 is in print standby, and after setting the
various printing conditions, the printing operation is carried out
upon pressing the print start key 105. The test print key 106 is
pressed to carry out a test print in the stencil printing apparatus
300. After setting the various conditions, a single test sheet is
printed upon pressing the test print key 106. The consecutive mode
key 107 is pressed, prior to pressing the platemaking start key
104, when the platemaking operation and the printing operation are
to be carried out consecutively. After pressing the consecutive
mode key 107 and inputting the printing conditions, pressing the
platemaking start key 104 causes the print operation to be carried
out following the plate discharge operation, the document reading
operation and the platemaking operation.
[0105] The clear/stop key 108 is pressed to stop the platemaking
operation or to clear a register in the stencil printing apparatus
300. The numerical keypad 109 is used for inputting numerical
values. The enter key 110 is pressed to set numerical values or the
like during the various setups, and the program key 111 is pressed
for recording and/or calling frequently executed operations. The
mode clear key 112 is pressed to clear the various modes and to
return to an initial state.
[0106] The printing speed setting key 113 is pressed to set a
printing speed, before the printing operation. A slower printing
speed is set, for instance, when more vivid images are desired, or
when atmospheric temperature is low, while a faster printing speed
is set, for instance, when attenuated images are desired, or when
atmospheric temperature is high.
[0107] The four direction keys 114 include an upper key 114a, a
lower key 114b, a left key 114c and a right key 114d. The direction
keys are pressed, for instance, to adjust image position during
image editing, or for selecting numerical values or items during
the various setups.
[0108] The paper size setting key 115 is pressed for inputting an
arbitrary paper size. The paper size inputted via the paper size
setting key 115 has priority over the paper size detected by the
paper size detection sensor 61. The paper thickness setting key 116
is pressed for inputting the thickness of the paper 100 prior to
two-side printing. In the present embodiment there can be selected
three types of thickness among "ordinary paper", "thin paper" and
"thick paper".
[0109] The display device 119, comprising a 7-segment LED, displays
mainly a print sheet count and the like. The display device 120
comprising an LCD has a hierarchical display structure. The
selection keys key 120a, 120b, 120c, 120d provided below the
display device 120 are pressed to allow switching between various
modes such as scaling, position adjustment and the like, and to
allow setting up the various modes. In addition to the display of
the status of the stencil printing apparatus 300, to the effect of
"platemaking/printing enabled" illustrated in the figure, the
display device 120 can display also an alarm in case of platemaking
or plate discharge jams, paper feeding or paper discharge jams or
the like, as well as indications for replenishing print paper,
masters, ink and so forth.
[0110] FIG. 8 is a control block diagram of the stencil printing
apparatus 300. In the figure, the control means 129, which is
well-known microcomputer having, for instance, a CPU 130, a ROM 131
and a RAM 132, is provided in the body of the stencil printing
apparatus 300.
[0111] On the basis of the various signals inputted via the
operation panel 103, the detection signals from the various sensors
provided in the body of the stencil printing apparatus 300, as well
as the operation program called from the ROM 131, the CPU 130
controls the various driving means provided in the printing section
15, the platemaking section 40, the paper feeding section 301, the
plate discharging section 80, the paper discharge section 20 and
the image reading section 50, to control the entire operation of
the stencil printing apparatus.
[0112] The operation programs of the entire stencil printing
apparatus are stored in the ROM 131. The operation programs can be
arbitrarily called by the CPU 130. The RAM 132 has, for instance,
the function of temporarily storing computation results of the CPU
130, and of storing, on demand, on/off signals and data signals
that are set and inputted by the various sensors and the various
keys on the operation panel 103.
[0113] The control means 129, moreover, grasps the position of the
plate cylinder 1 on the basis of home position signals from a home
position sensor 134 and signals from an encoder, not shown,
provided in the plate cylinder driving means 121.
[0114] The operation of the stencil printing apparatus 300 is
explained next on the basis of the above constitution.
[0115] The operator stacks paper 100, used for printing, on the
paper feeding tray 60, opens the pressure plate 51, sets the
document to be printed on the contact glass 52, and closes then the
pressure plate 51. Thereafter, the operator sets up the platemaking
conditions by way of the various keys on the operation panel 103,
and presses then the platemaking start key 104.
[0116] An instance of one-side printing, through pressing of the
one-side printing key 118, will be explained first. The operator
presses the platemaking start key 104. When the platemaking start
key 104 is pressed, a paper size detection signal from the paper
size detection sensor 61, and a document size detection signal from
the document size detection sensor 55 are sent to the control means
129, which compares the received signals.
[0117] When the paper size is identical to the document size, the
image reading operation is carried out immediately. When the paper
size is different from the document size, the control means 129
displays a notice to that effect on the display device 120, to warn
the operator. When the paper size and the document size are
different, magnification or reduction scaling may be automatically
carried out following an instruction from the control means 129, in
such a way so as to match document size and image size.
[0118] When the platemaking start key 104 is pressed, the reading
operation of the document images is carried out in the image
reading section 50. Reflection light exposed by a fluorescent lamp
is reflected at various reflective mirrors. The read document image
is condensed by the lens 53 and strikes then the image sensor 54,
to carry out document image reading by photoelectric
conversion.
[0119] The electric signals resulting from photoelectric conversion
are inputted into an A/D converter, not shown, and are stored then
in an image memory 135 as image data signals.
[0120] In parallel to the image reading operation in the image
reading section 50 there is carried out a plate discharge operation
at the plate discharging section 80, where a used master is
separated from the outer peripheral face of the plate cylinder 1.
The plate cylinder 1 starts rotating when the platemaking start key
104 is pressed. When the plate cylinder 1 reaches the home position
illustrated in FIG. 7, the dog 29, not shown, in the figure is
detected by the home position sensor 28, whereupon the home
position sensor 28 sends a home position signal to the control
means 129.
[0121] Having received the home position signal, the control means
129 measures the number of pulses generated by an encoder, not
shown, taking the home position as a reference. The control means
129 discontinues the operation of the plate cylinder driving means
121 when the control means 129 judges that the leading end of the
used master wrapped on the outer peripheral face of the plate
cylinder 1 has reached a predefined plate discharge position,
opposite the endless belt on the outer peripheral face of the
driven roller of the plate discharging section 80.
[0122] When the plate cylinder driving means 121 stops, and the
plate cylinder 1 stops as a result at a predefined plate discharge
position, the plate cylinder driving means 121 and the plate
discharging driving means 126 operates to rotationally drive the
respective driving rollers and to move the lower plate discharging
member 82 towards the plate cylinder 1, whereby the endless belt on
the outer peripheral face of the driven roller abuts the used
master on the plate cylinder 1.
[0123] The used master, scooped up from the outer peripheral face
of the plate cylinder 1 through the rotation of the plate cylinder
1 and the movement of the endless belt, is sandwiched and
transported between the lower plate discharging member 82 and the
upper plate discharging member 81, becoming thereby separated from
the outer peripheral face of the plate cylinder 1. The separated
used master is disposed inside the plate discharge 83, where it is
compressed by the compression plate 84.
[0124] The plate cylinder 1 continues rotating, after the used
master has been completely separated from the outer peripheral face
of the plate cylinder 1, until the damper 6 reaches an upper-right
plate feeding standby position, whereupon the plate cylinder 1
stops.
[0125] When the plate cylinder 1 stops at the plate feeding standby
position, an opening and closing means, not shown, operates to open
the damper 6, which is thus brought into plate feeding standby. The
platemaking operation is carried out in the platemaking section 40
in parallel to the plate discharge operation. When the platemaking
start key 104 is pressed, a master is drawn from the master roll as
a result of the rotational driving of the platen roller 42, the
tension roller pair 46 and the reversing roller pair 47.
[0126] The movable master guide plate, not shown, becomes
positioned at a transport position. When the image forming region
of the drawn master reaches a position facing the thermal elements
of the thermal head 43, the image data signals stored in the image
memory, not shown, are called after being subjected to image
processing. A thermal head driver, not shown, selectively causes
the thermal elements of the thermal head 43 to generate heat, to
form thereby a platemaking image on the surface of the
thermoplastic resin film of the master.
[0127] The master is transported as it is being perforated, and
when the leading end of the master is clamped by the reversing
roller pair 47, the movable master guide plate, not shown, moves to
a retreat position, and the rotation of the reversing roller pair
47 stops.
[0128] The platen roller 42 and the tension roller pair 46 go on
rotating after the reversing roller pair 47 stops rotating, whereby
the prepared master, perforated by the thermal head 43, becomes
stored in the master stocking section 45.
[0129] When the reversing roller pair 47 stops, a suction fan, not
shown, provided in the master stocking section 45 operates to
suction the prepared master and to afford thus good master storage
in the master stocking section 45.
[0130] When in the above platemaking operation the stencil printing
apparatus 300 is in the plate feeding standby state after the plate
discharge operation is over, the reversing roller pair 47 starts
rotating, whereupon the prepared master stored in the master
stocking section 45 is transported between the stage, not shown,
and the open damper 6.
[0131] When the leading end of the prepared master is transported
up to a predefined position at which the leading end can be clamped
by the damper 6, the opening and closing means, not shown, operate
to close the damper 6, whereupon the leading end of the master is
held against the outer peripheral face of the plate cylinder 1 by
the damper 6 and the stage not shown.
[0132] The plate cylinder 1 is rotationally driven intermittently
in the clockwise direction in FIG. 7, as a result of which the
prepared master becomes wrapped around the plate cylinder 1.
Thereupon, the rotation of the reversing roller pair 47 stops, and
the one-way clutch, not shown, provided in the driving roller, not
shown, co-rotates accompanying the drawing of the prepared
master.
[0133] When the image data signal from the image memory is
interrupted, the operation of the thermal head 43 stops. When the
one prepared master is transported, the rotation of the platen
roller 42, the tension roller pair 46 and the reversing roller pair
47 stops, and the cutting means 44 operates to cut off the prepared
master.
[0134] The prepared master thus cut off is drawn out of the
platemaking section 40 through the rotation of the plate cylinder
1. The plate cylinder 1 rotates up to the home position, where it
stops, to conclude the platemaking operation and the plate feeding
operation. The plate fixing operation follows then on the plate
feeding operation.
[0135] When the plate cylinder 1 stops at the home position, the
paper separation pawls 17 become positioned in the vicinity of the
peripheral face of the plate cylinder 1, whereafter a press roller
locking means and a stepping motor, not shown, operate to cause a
stepped cam to rotate, whereupon a abuts a cam follower. As a
result, a movable arm swings around a pivot shaft, and a camshaft
moves to a position at which a cam plate can abut a cam follower.
Thereafter, the action of the press roller locking means, not
shown, is disabled.
[0136] Next, the paper feeding roller 10a, the separation roller
10b, the driving rollers 25a and the suction fan 26 are driven
while the plate cylinder 1 is rotationally driven, at low speed, in
the clockwise direction of FIG. 7, whereupon the uppermost sheet of
the paper 100 stacked on the paper feeding tray 60 is drawn and the
leading end of the sheet is clamped by the resist roller pair
12.
[0137] The resist roller pair 12 is rotationally driven with the
predetermined timing with which the leading end portion in the
plate cylinder rotation direction of the image forming region of
the prepared master, wrapped around the plate cylinder 1, reaches a
position corresponding to the press roller 13, whereupon the drawn
paper 100 is fed between the plate cylinder 1 and the press roller
13.
[0138] A camshaft, not shown, and a multi-stage cam, not shown,
formed integrally with the camshaft, are rotationally driven by way
of a press roller contact/separation mechanism 155 in synchrony
with the rotation of the plate cylinder 1. A protrusion of the cam
plate, not shown, having moved as described above to a position
where it can abut the cam follower, not shown, is released from the
cam follower, not shown, with the above-described predetermined
timing.
[0139] As a result, the peripheral face of the press roller 13 is
pressed against the outer peripheral face of the plate cylinder 1,
through the urging force of a pressing spring, not shown, so that
the paper 100 fed by the resist roller pair 12 is pressed against
the master that is wrapped around the plate cylinder 1.
[0140] Through this pressing operation, the press roller 13, the
paper 100, the prepared master and the plate cylinder 1 are brought
into pressure contact with one another, whereupon the ink supplied
by the ink roller 3 to the inner peripheral face of the plate
cylinder 1 bleeds out through openings in the plate cylinder 1. The
ink fills the porous support plate, not shown, and the mesh screen,
not shown, comprised in the plate cylinder 1, as well as the porous
support of the prepared master that is wrapped around the plate
cylinder 1, and is transferred to the paper 100, via the perforated
portions in the prepared master, in a so-called plate fixing
operation.
[0141] The paper 100 becomes printed paper 101 by having had
printed thereon a platemaking image during plate fixing. The
leading end portion of the printed paper 101 is separated from the
prepared master, on the outer peripheral face of the plate cylinder
1, through the action of the paper separation pawls 17.
[0142] The printed paper 101 thus separated moves downward to be
fed to the discharge paper transport unit 21. There, the printed
paper 101 hugs the top face of the endless belt 27, on account of
the suction force of the suction fan 26, while being transported
leftwards, to be outputted onto the discharge paper tray 70.
Thereafter, the plate cylinder 1 rotates again up to the home
position, where it stops, to finish thereby the plate fixing
operation, and bringing the stencil printing apparatus 300 to print
standby.
[0143] Once the stencil printing apparatus 300 is in print standby,
and after the printing conditions have been inputted via the
printing speed setting key 113 and the various keys on the
operation panel 103, a test print is carried out by pressing the
test print key 106. When the test print key 106 is pressed, the
plate cylinder 1 is rotationally driven at the set printing speed,
and one sheet of paper 100 is fed out of the paper feeding section
301.
[0144] The fed paper 100 stops temporarily at the resist roller
pair 12. Thereafter, the paper is transported with the same timing
as the plate fixing time, and is brought, by the press roller 13,
into pressure contact with the prepared master on the outer
peripheral face of the plate cylinder 1. The paper separation pawls
17 separate the printed paper 101, having had an image printed
thereon, from the prepared master on the outer peripheral face of
the plate cylinder 1. The printed paper 101 is then transported by
the discharge paper transport unit 21 and is outputted onto the
discharge paper tray 70.
[0145] Once image position, density and so forth are checked on the
test print, and after inputting the number of print sheets via the
numerical key pad 109, the print start key 105 is pressed,
whereupon paper 100 is continuously fed out of the paper feeding
section 301, to carry out the printing operation under the same
conditions as in the test print. Once the set number of print
sheets has been processed, the plate cylinder 1 stops at the home
position, whereby the stencil printing apparatus 300 is brought
again to print standby.
[0146] The present invention allows matching the paper transport
speed and the printing speed in the printing device after the paper
has been printed by the inkjet printing section, in the paper
feeding device. As a result, the invention succeeds in providing a
hybrid printing system with enhanced usability and operational
efficiency, in which the functionality on the printing device is
not constrained.
[0147] Moreover, the invention allows matching, with high
precision, paper transport timing with printing timing in the
inkjet printing section, so that printing can be carried out
without image shift.
[0148] Also, the cleaning operation of the inkjet heads can be
performed in response to an instruction from the printing device,
whereby the cleaning operation can be carried out in accordance
with the number of print sheets, or during a temporary printing
stop, during mass printing, while preventing function impairment on
account of, for instance, clogging in the inkjet printing
section.
[0149] An inkjet printer can also be easily constructed, with
enhanced usability, when the paper feeding device is directly
connected to the paper discharge device.
[0150] Moreover, printing can be diversified by storing print data
in an internal memory and by reading the data upon printing.
[0151] Various modifications will become possible for those skilled
in the art after receiving the teachings of the present disclosure
without departing from the scope thereof.
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