Title: Method of controlling a drying apparatus for a printing press, drying apparatus and printing press
Abstract: In a drying apparatus equipped with a light source to dry a drying matter of a print by irradiating light of the light source to the print, a correlation between information relating to the time for which the light source is lit and information relating to the amount of light of the light source is preset. Then, the information relating to the elapsed time for which the light source is lit during the light source is lit is detected so that light of the light source is controlled to a constant amount, regardless of the elapsed time for which the light source is lit, based on information relating to a reference amount of light, which information is obtained from the preset correlation between the information relating to the time for which the light source is lit and the information relating to the amount of light with reference to the information relating to the elapsed time at the time of the detection.
Patent Number: 6,981,448 Issued on 01/03/2006 to Kimura
| Inventors:
|
Kimura; Takashi (Fuchu, JP)
|
| Assignee:
|
Ryobi Ltd. (JP)
|
| Appl. No.:
|
850869 |
| Filed:
|
May 21, 2004 |
Foreign Application Priority Data
| May 27, 2003[JP] | 2003-149256 |
| Current U.S. Class: |
101/488; 101/484; 101/483 |
| Current Intern'l Class: |
B41L 35/14 (20060101) |
| Field of Search: |
101/488,484,483
|
References Cited [Referenced By]
U.S. Patent Documents
| 4698767 | Oct., 1987 | Wensel et al.
| |
| 5937761 | Aug., 1999 | Buschmann et al.
| |
| 6877247 | Apr., 2005 | DeMoore.
| |
| 2003/0206225 | Nov., 2003 | Ihme.
| |
| Foreign Patent Documents |
| 02-039940 | Aug., 1990 | JP.
| |
Primary Examiner: Nolan, Jr.; Charles H.
Attorney, Agent or Firm: Perkins Coie LLP
Claims
What is claimed is:
1. A method of controlling a drying apparatus for a printing press, in which
said drying apparatus is equipped with a light source to dry a drying matter of
a print by irradiating light of said light source on said print, comprising:
presetting a correlation between information relating to the time for which said
light source is lit and information relating to the amount of light of said light
source;
detecting information relating to the elapsed time for which the light source
is lit during said light source is lit; and
controlling light of the light source to a constant amount, regardless of the
elapsed time for which the light source is lit, based on information relating to
a reference amount of light, said information relating to the reference amount
being obtained from the preset correlation between said information relating to
the time for which the light source is lit and said information relating to the
amount of light with reference to said information relating to the elapsed time
at the time of the detection.
2. A method of controlling a drying apparatus for a printing press, in which
said drying apparatus is equipped with a light source to dry a drying matter of
a print by irradiating light of said light source on said print, comprising:
presetting a correlation between information relating to the value of the electric
current passing through said light source and information relating to the amount
of light of said light source;
detecting information relating to the value of the electric current passing through
said light source during said light source is lit; and
controlling light of the light source to a constant amount, regardless of the
elapsed time for which the light source is lit, based on information relating to
a reference amount of light, said information relating to the reference amount
being obtained from the preset correlation between said information relating to
the value of the electric current and said information relating to the amount of
light with reference to said information relating to the value of the electric
current at the time of the detection.
3. The method of controlling a drying apparatus according to claim 1, wherein
said light source is a UV lamp.
4. The method of controlling a drying apparatus according to claim 2, wherein
said light source is a UV lamp.
5. A drying apparatus for a printing press equipped with a light source to dry
a drying matter of a print by irradiating light of said .light source on said print, comprising:
a setting means for presetting a correlation between information relating to
the time for which said light source is lit and information relating to the amount
of light of said light source;
a detection device for detecting information relating to the elapsed time for
which said light source is lit during said light source is lit; and
a light source control part for controlling light of said light source to a constant
amount, regardless of the elapsed time for which said light source is lit, based
on information relating to a reference amount of light, said information relating
to the reference amount of light being obtained from the preset correlation between
said information relating to the time for which said light source is lit and said
information relating to the amount of light with reference to said information
relating to the elapsed time at the time of the detection.
6. A drying apparatus for a printing press equipped with a light source to dry
a drying matter of a print by irradiating light of said light source on said print, comprising:
a setting means for presetting a correlation between information relating to
the value of the electric current passing through said light source and information
relating to the amount of light of said light source;
a detection device for detecting information relating to the value of the electric
current passing through said light source during said light source is lit; and
a light source control part for controlling light of said light source to a constant
amount, regardless of the elapsed time for which said light source is lit, based
on information relating to a reference amount of light, said information relating
to the reference amount of light being obtained from the preset correlation between
said information relating to the value of the electric current passing through
said light source and said information relating to the amount of light with reference
to said information relating to the elapsed time at the time of the detection.
7. The drying apparatus according to claim 5, wherein said light source is a
UV lamp.
8. The drying apparatus according to claim 6, wherein said light source is a
UV lamp.
9. A printing press equipped with said drying apparatus according to claim 5.
10. A printing press equipped with said drying apparatus according to claim 6.
Description
CROSS REFERENCE TO RELATED APPLICATION
This application claims priority from Japanese Patent Application No. 2003-149256,
which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method of controlling a drying apparatus for
a printing press, in which a matter to be dried (hereinafter referred to a drying
matter) of a print is dried by irradiating light from a light source to the print,
a drying apparatus and a printing press.
2. Related Art
A conventional drying apparatus hitherto known such as in Japanese Patent No.
2958955
(JP-A-1990-39940) is equipped with a light source (e.g., a UV (ultraviolet ray)
lamp), from which light is irradiated on a print so as to dry a drying matter (e.g.,
printing ink and vanish) on the print. The drying apparatus of this type is disposed
on a print conveying passage so as to subsequently dry drying matters of oncoming prints.
In the drying apparatus equipped with a light source that irradiates light on
a print, the amount of light is generally easy to be decreased as the time for
which the drying apparatus is used or the time for which light is irradiated elapses.
This poses a problem that drying capability for drying matters of prints is deteriorated
in response to the decrease of the amount of light.
In order to address the problem that the amount of light is decreased as the
time
for which the light source is lit is elapsed, a well-experienced operator manually
adjusts the light-source control voltage that controls the light source based on
his experience so as to allow the light source to irradiate a proper amount of
light, thereby maintaining the drying capability of the drying apparatus for better
result in drying operation.
However, an operator with less experience is hard to properly maintain the
drying capability of the drying apparatus even by the manual adjustment to the
amount of light of the light source, causing insufficient drying of prints. An
insufficiently dried matter of each print might be smeared to the next print stacked
thereon (set-off), or cause a print to be adhered to the next print, so that it
is likely to cause a print to be discarded or broke unfit for use (hereinafter
simply referred to-broke).
In consideration of the above problems, it is an object of the present invention
to provide a method of controlling a drying apparatus that dries drying matters
of prints by irradiating light of a light source on prints, which allows the drying
apparatus to have a constant capability to dry the drying matters even in a case
where the amount of light of the light source is decreased due to the elapse of
the lighting time of the light source, thereby maintaining a good drying quality
of prints, preventing set-off of drying matters and adhesion of a print to the
next print and hence limiting production of broke. It is another object of the
present invention to provide a drying apparatus and a printing press that can carry
out this method.
SUMMARY OF THE INVENTION
The present inventors repeatedly engaged in intensive study and found the following matters.
Before the drying operation of a drying apparatus equipped with a light source
used in a printing press, a correlation between information relating to the time
for which the light source is lit (for example of this information: the time for
which the light source is lit) and information relating to the amount of light
of the light source (an example of this information: the light-source control voltage
that controls the amount of light of the light source) is preset, and during the
light source is lit, information relating to the elapsed time for which the light
source is lit (an example of this information: the elapsed time for which the light
is lit) is detected. Accordingly, it is possible to control light of the light
source to a constant amount, regardless of the elapsed time for which the light
source is lit, based on information relating to a reference amount of light, which
information is obtained from the preset correlation between the information relating
to the time for which the light source is lit and the information relating to the
amount of light with reference to the information relating to the elapsed time
at the time of detection. Throughout the description, by a constant amount is meant
a substantially constant amount which might have fluctuation within a permissible tolerance.
Decrease in the amount of light source appears in value of the electric
current passing through the light source. In consideration of this fact, before
the drying operation of a drying apparatus, a correlation between information relating
to the value of the electric current passing through the light source (an example
of this information: the value of the electric current passing through the light
source) and information relating to the amount of light of the light source (an
example of this information: the light-source control voltage that controls the
amount of light of the light source), and during the light source is lit, information
relating to the value of the electric current passing through the light source
(an example of this information: the value of the electric current passing through
the light source) is detected. Accordingly, it is possible to control light irradiated
from the light source to a constant amount, regardless of the elapsed time for
which the light source is lit, based on information relating to a reference amount
of light, which information is obtained from the preset correlation between the
information relating to the value of the electric current and the information relating
to the amount of light with reference to the information relating to the value
of the electric current passing through the light source at the time of the detection.
The present invention has been conceived on the basis of the above findings.
In order to achieve the above object, there are provided a method of controlling
a drying apparatus for a printing press, a drying apparatus and a printing press.
According to a first aspect of the present invention, there is provided
a method of controlling a drying apparatus for a printing press, in which the drying
apparatus is equipped with a light source to dry a drying matter of a print by
irradiating light of the light source on the print, the method including presetting
a correlation between information relating to the time for which the light source
is lit and information relating to the amount of light of the light source; detecting
information relating to the elapsed time for which the light source is lit during
the light source is lit; and controlling light of the light source to a constant
amount, regardless of the elapsed time for which the light source is lit, based
on information relating to a reference amount of light, which information is obtained
from the preset correlation between the information relating to the time for which
the light source is lit and the information relating, to the amount of light with
reference to the information relating to the elapsed time at the time of the detection.
According to a second aspect of the present invention, there is provided
a method of controlling a drying apparatus for a printing press, in which the drying,
apparatus is equipped with a light source to dry a drying matter of a print by
irradiating light of the light source to the print, the method including presetting
a correlation between information relating to the value of the electric current
passing through the light source and information relating to the amount of light
of the light source; detecting information relating, to the value of the electric
current passing through the light source during the light source is lit; and controlling
light of the light source to a constant amount, regardless of the elapsed time
for which the light source is lit, based on information relating to a reference
amount of light, which information is obtained from the preset correlation between
the information relating to the value of the electric current and the information
relating to the amount of light with reference to the information relating to the
value of the electric current passing through the light, source at the time of
the detection.
According to a third aspect of present invention, there is provided a drying
apparatus for a printing press equipped with a light source to dry a drying matter
of a print by irradiating light of the light source on the print, the drying apparatus
including a setting means for presetting a correlation between information relating
to the time for which the light source is lit and information relating to the amount
of light of the light source; a detection device for detecting information relating
to the elapsed time for which the light source is lit during the light source is
lit; and a light-source control part for controlling light of the light source
to a constant amount, regardless of the elapsed time for which the light source
is lit, based on information relating to a reference amount of light, which information
is obtained from the preset correlation between the information relating to the
time for which the light source is lit and the information relating to the amount
of light with reference to the information relating to the elapsed time at the
time of the detection.
According to a fourth aspect of the present invention, there is provided
a drying apparatus for a printing press equipped with a light source to dry a drying
matter of a print by irradiating light of the light source on the print, the drying
apparatus including a setting means for presetting a correlation between information
relating to the value of the electric current passing through the light source
and information relating to the amount of light of the light source; a detection
device for detecting information relating to the value of the electric current
passing through the light source during the light source is lit; and a light-source
control part for controlling light of the light source to a constant amount, regardless
of the elapsed time for which the light source is lit, based on information relating
to a reference amount of light, which information is obtained from the preset correlation
between the information relating to the value of the electric current and the information
relating to the-amount of light, with reference to the information relating to
the value of the electric current passing through the light source at the time
of the detection.
According to a fifth aspect of the present invention, there is provided
a printing press that includes the drying apparatus of the third aspect of the
present invention, in which a correlation between information relating to the time
for which the light source is lit and information relating to the amount of light
of the light source is preset in the setting means; information relating to the
elapsed time for which the light source is lit is detected by the detection device
during the light source is lit; and light of the light source is controlled to
a constant amount by the light-source control part, regardless of the elapsed time
for which the light source is lit, based on information relating to a reference
amount of light, which information is obtained from the preset correlation between
the information relating to the time for which the light source is lit and the
information relating to the amount of light, with reference to the information
relating to the elapsed time at the time of the detection.
According to a sixth aspect of the present invention, there is provided
a printing press that includes the drying apparatus of the fourth aspect of the
present invention, in which a correlation between information relating to the value
of the electric current passing through the light source and information relating
to the amount of light of the light source is preset in the setting means; information
relating to the value of the electric current passing through the light source
is detected by the detection device during the light source is lit; and light of
the light source is controlled to a constant amount by the light-source control
part, regardless of the elapsed time for which the light source is lit, based on
information relating to a reference amount of light, which information is obtained
from the preset correlation between the information relating to the value of the
electric current and the information relating to the amount of light, with reference
to the information relating to the value of the electric current passing through
the light source at the time of the detection.
According to the above controlling method, the drying apparatus and the
printing press, in which light of the light source is controlled to a constant
amount, regardless of the elapsed time for which the light source is lit, based
on information relating to a reference amount of light, which information is obtained
from the preset correlation between the information relating to the time for which
the light source is lit and the information relating to the amount of light with
reference to the information relating to the elapsed time at the time of the detection,
it is possible to allow the drying apparatus to maintain a substantially constant
drying capability even in a case where the light intensity characteristics of the
light source is decreased as the time for which the light source is lit is elapsed,
and thus maintain an optimum drying condition of the prints. As a result, set-off
of drying matters to the next print or adhesion of a print to the next print can
be prevented, thereby limiting the possibility to produce broke. The same desirable
effects can be produced by the method, drying apparatus and printing press, in
which light of the light source is controlled to a constant amount, regardless
of the elapsed time for which the light source is lit, based on information relating
to a reference amount of light, which information is obtained from the preset correlation
between the information relating to the value of the electric current and the information
relating to the amount of light with reference to the information relating to the
value of the electric current at the time of the detection.
In the method and the drying apparatus of the first and third aspect of the present
invention, as the information relating to the time for which the light source is
lit, the time for which the light source is lit can be cited as a typical example,
while various information can be employed as long as it is related to the time
for which the light source is lit. For example, the number of prints, the operation
time of the printing press or the like may be employed. Also, as the information
relating to the amount of light of the light source, the amount of light of the
light source can be cited as a typical example.
In a case where the time for which the light source is lit is designated as the
information relating to the time for which the light source is lit while the amount
of light of the light source is designated as the information relating to the amount
of light of the light source, a correlation between the time for which the light
source is lit and the amount of light of the light source may be designated as
the preset correlation between the information relating to the time for which the
light source is lit and the information relating to the amount of light of the
light source, so that the time for which the light source is accumulated and detected
as the elapsed time for which the light source is ht during the light source is
lit. Accordingly, a light-source control voltage that controls the light source
to emit a constant amount of light regardless of the elapsed time for which the
light is lit is calculated based on a reference amount of light obtained from the
preset correlation between the time for which the light source is lit and the amount
of light of the light source with reference to the elapsed time at the time of
the detection. The thus calculated light-source control voltage can control the
light source to emit a constant amount of light regardless of the elapsed time
for which the light source is lit. In this case, the correlation between the time
for which the light source is lit and the amount of light of the light source may
be set by using a light-amount compensation table for storage of the aforesaid
correlation, or a calculation formula to calculate an approximate correlation to
the aforesaid correlation.
According to the above case, the correlation preset in the drying apparatus
between the information relating to the time for which the light source is lit
and the information relating to the amount of light of the light source is the
correlation between the time for which the light source is lit and the amount of
light of the light source. As the detection device for detecting information relating
to the elapsed time for which the light source is lit, a device that accumulates
the time for which the light source is lit and detects an accumulated time as the
elapsed time is employed. Accordingly, the light-source control part may calculate
a light-source control voltage, which controls light of the light source to a constant
amount regardless of the elapsed time for which the light source is lit, based
on a reference amount of light obtained from the correlation between the time for
which the light source is lit and the amount of light of the light source preset
in the setting means, with reference to the elapsed time, for which the light source
is lit, detected by the detecting device, and control light of the light source
to a constant amount regardless of the elapsed time, for which the light source
is lit, by using the thus calculated light-source control voltage. Also, the setting
means may contain a light-amount compensation table for storage of the correlation
between the time for which the light source is lit and the amount of light of the
light source, or a calculation formula to calculate an approximate correlation
to the aforesaid correlation.
In the control method and the drying apparatus using the information relating
to the value of the electric current passing through the light source, the value
of the electric current passing through the light source can be cited as a typical
example of this information. The impedance of the light source may be used as the
information. Also, the amount of light of the light source can be cited as a typical
example of the information relating to the amount of light of the light Source.
In a case where the value of the electric current passing through the light source
is designated as the information relating to the value of the electric current
passing through the fight source while the amount of light of the light source
is designated as the information relating to the amount of light of the light source,
a correlation between the value of the electric current passing through the light
source and the amount of light of the light source may be designated as the preset
correlation between the information relating to the value of the electric current
passing through the light source and the information relating to the amount of
light of the light source, so that the value of the electric current passing through
the light source is detected during the light source is lit. Accordingly, a light-source
control voltage that controls the light source to emit a constant amount of light
regardless of the value of the electric current passing through the light source
is calculated based on a reference amount of light obtained from the preset correlation
between the value of the electric current passing through the light source and
the amount of light of the light source. The thus calculated light-source control
voltage can control the light source to emit a constant amount of light regardless
of the elapsed time for which the light source is lit. In this case, the correlation
between the value of the electric current passing through the light source and
the amount of light of the light source may be set by using a light-amount compensation
table for storage of the aforesaid correlation, or a calculation formula to calculate
an approximate correlation to the aforesaid correlation.
According to the above case, the correlation preset in the drying apparatus
between the information relating to the value of the electric current passing through
the light source and the information relating to the amount of light of the light
source is the correlation between the value of the electric current passing through
the light source and the amount of light of the light source. As the detection
device for detecting information relating to the value of the electric current
passing through the light source, a device that detects the value of the electric
current passing through the light source is employed. Accordingly, the light-source
control part may calculate a light-source control voltage, which controls light
emitted from the light source to a constant amount regardless of the value of the
electric current passing through the light source, based on a reference amount
of light obtained from the correlation between the value of the electric current
passing through the light source and the amount of light of the light source preset
in the setting means, with reference to the value of the electric current passing
through the light source detected by the detecting device, and control light of
the light source to a constant amount regardless of the elapsed time, for which
the light source is lit, by using the thus calculated light-source control voltage.
Also, the setting means may contain a light-amount compensation table for storage
of the correlation between the value of the electric current passing through the
light source and the amount of light of the light source, or a calculation formula
to calculate an approximate correlation to the aforesaid correlation.
In either case, as the light source, an UV (ultraviolet) lamp can be cited as
a typical example, although it is not necessarily limited to this. Alternatively,
an IR (infrared) lamp can be used.
BRIEF DESCRIPTION OF THE DRAWINGS
The above, and other objects, features and advantages of the present invention
will become apparent from the detailed description thereof in conjunction with
the accompanying drawings wherein.
FIG. 1 is a schematic side elevational view of a printing press equipped with
a drying apparatus that carries out the method of controlling the drying apparatus
according to the present invention.
FIG. 2A is a schematic block diagram illustrating a structure of an essential
portion including a main control part and a first-UV-lamp control circuit in a
case where the drying apparatus of the first embodiment is mounted in the printing
press. FIG. 2B is a schematic block diagram illustrating a structure of an essential
portion including the main control part and a second-UV-lamp control circuit in
a case where the drying apparatus of the second embodiment is mounted in the printing press.
FIG. 3 is a graph illustrating an example of the light intensity characteristics
relative to the light-source control voltage in solid line and a graph plotted
by taking the reciprocal of the aforesaid graph.
FIG. 4 is a graph illustrating an example of the light intensity characteristics
relative to the time for which a UV lamp is lit.
FIG. 5 is a graph illustrating a correlation between the time for which a UV
lamp is lit and the light-source control voltage that controls light of the UV
lamp to a constant amount regardless of the elapsed time for which the UV lamp
is lit.
FIG. 6 is a graph illustrating an example of the electric current characteristics
relative to the amount of light of the UV lamp.
FIG. 7 is a graph illustrating a correlation between the value of the electric
current passing through a UV lamp and the light-source control voltage that controls
light of the UV lamp to a constant amount regardless of the elapsed time for which
the UV lamp is lit.
FIG. 8A is a flowchart illustrating an example of a drying operation flow applied
to dry prints by the drying apparatus of the first embodiment. FIG. 8B is a flowchart
illustrating an example of a drying operation flow applied to dry prints by the
drying apparatus of the second embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Various embodiments of the present invention will be herein described with
reference to the drawings attached hereto. FIG. 1 is a schematic side elevational
view illustrating a structure of a printing press A equipped with a drying apparatus
(a first drying apparatus
50 or a second drying apparatus
50′)
that carries out the method of controlling the drying apparatus according to the
present invention.
The printing press A of FIG. 1 is designed to be capable of performing single-side
printing operation and both-side printing operation, and includes a sheet feeding
section
10 for feeding substrates (sheets of paper in this embodiment) P
to first and second printing sections
20X,
20Y hereinafter described,
the first and second printing sections
20X,
20Y at which sheets P
fed from the sheet feeding section
10 are printed, a turnover device
30
located between the first and second printing sections
20X,
20Y for
turning sheets P with one side printed at the first printing section located upstream
thereof along the sheet transfer direction ("X" in FIG. 1) upside down and a sheet
discharging section
40 for discharging sheets printed at the first and second
printing sections
20X,
20Y, as well as the first drying apparatus
50 or the second drying apparatus
50′.
More specifically, the printing press A is operated so that when the single-side
printing operation is performed, sheets P are fed from the sheet feeding section
10 to the first and second printing sections
20X,
20Y, thereby
allowing the sheets P fed to have one side printed by plural printing units of
the first and second printing sections
20X,
20Y (eight printing units
20a-
20b in this embodiment) and then to be discharged
through the sheet discharging section
40, and when the both-side printing
operation is performed, sheets P are fed from the sheet feeding section
10
to the first printing section
20X, thereby allowing the sheets P to have
one side printed by plural printing units (four printing units
20a-
20d
in this embodiment) of the first printing section
20X located upstream
of the turnover device
30 along the sheet transfer direction X, and be turned
upside down by the turnover device
30, then have another side printed by
plural printing units (four printing units
20e-
20h in
this embodiment) of the second printing section
20Y located downstream of
the turnover device
30 along the sheet transfer direction X, and then be
discharged through the sheet discharging section
40.
The sheet feeding section
10 includes a sheet storage part
11 and
a sheet feeding part
12. The sheet storage part
11 is designed to
be capable of storing plural sheets P. The sheet feeding part
12 is designed
to be capable of pulling sheets P stored in the sheet storage part
11 one
by one and transfer the same towards the first printing section
20X. Thus,
the sheets P are fed to the first printing section
20X.
The printing press A includes a surface treatment unit
20i in addition
to the first and second printing sections
20X,
20Y. As described
above, the first printing section
20X includes the printing units
20a-
20d,
while the second printing section
20Y includes the printing units
20e-
20h.
In the printing units
20a-
20h of the first and second
printing sections
20X,
20Y, plate cylinders
21a-
21h,
rubber cylinders
22a-
22h and impression cylinders
23a-
23h
are arranged in combination in the respective units to constitute an essential
structure of each printing unit. The surface treatment unit
20i includes
an anilox roller
26, a varnish cylinder
27 and an impression cylinder
23i.
A reference code
24a represents a transfer cylinder in the printing
unit
20a, while reference codes
24b-
24d represent
transfer cylinders in the printing units
20b-
20d, and
reference codes
24f-
24h represent transfer cylinders
in the printing units
20f-
20b. A transfer cylinder
24g of the printing unit
20g is omitted in FIG.
1.
Regarding the turnover device
30, reference codes
31,
32,
and
33 respectively represent a transfer cylinder, a turnover and transfer
cylinder, and a turnover cylinder.
In the respective printing units
20a-
20h, printing
plates (not shown) are mounted on the plate cylinders
21a-
21h.
Ink and water are supplied onto these plates and then ink thereon is transferred
onto the rubber cylinders
22a-
22h as the rotation of
the printing plates. Ink transferred on the rubber cylinders
22a-
22h
are then transferred on sheets P, which are held between the rubber cylinders
22a-
22b and the impression cylinders
23a-
23h.
Whereby, sheets P fed from the sheet feeding section
10 can be printed corresponding
to the printing plates mounted thereon.
At the surface treatment unit
201, varnish for surface treatment is supplied
to the anilox roller
26 and then transferred therefrom onto the varnish
cylinder
27. Varnish transferred on the varnish cylinder
27 is then
transferred onto sheets P upcoming as being held between the varnish cylinder
27
and the impression cylinder
23i. Whereby, the surface treatment can
be applied on the sheets P coming from the printing unit
20h.
The sheet discharging section
40 includes a transfer member
41
and a storage member
42. At this sheet discharging section
40, sheets
P transferred by the impression cylinder
23i of the surface treatment
unit
20i each are held at its leading end by a holding part (not
shown) of the transfer member
41, and are transferred along a substantially
lower side of the transfer member
41 into the storage member
42,
as illustrated in FIG.
1. Sheets P thus transferred by the transfer member
41 are accommodated in the storage member
42.
The first drying apparatus
50 in a case where it is provided in the printing
press A includes an interdeck dryer member
51 located above the turnover
device
30, dryer members
52,
53 located along an inner side
of the transfer member
41 and a first UV lamp control circuit
54
(see also FIG.
2A). The second drying apparatus
50′ in a case
where it is provided in the printing press A has the same arrangement, except that
instead of the first UV lamp control circuit
54 of the first drying apparatus,
a second UV lamp control circuit
54′ (see FIG. 2B) is provided.
The interdeck dryer member
51 is herein a UV dryer provided as a light
source with a UV (ultraviolet ray) lamp
51 a that can irradiate UV rays
from above the transfer cylinder
32 of the turnover device
30. Printing
ink on sheets P (substrates) printed at the first printing section
20X is
dried by irradiating UV rays from the UV lamp
51a.
The dryer member
52 is a UV dryer provided as a light source with a UV
(ultraviolet ray) lamp
52a that can irradiate UV rays from inside
of the transfer member
41. The dryer member
53 is an IR (infrared
ray) dryer provided as a light source with an IR lamp
53a that can
irradiate IR rays from inside of the transfer member
41. These UV dryer
52 and IR dryer
53 are arranged so as to irradiate UV rays from the
UV lamp
52a and IR rays from the IR lamp
53a to sheets
P (substrates) that are printed at the first and second printing sections
20X,
20Y and coated with varnish, thereby drying printing ink and varnish of
the sheets P.
The UV lamps
51a,
52a of the UV dryer members
51,
52 are herein connected to the first UV lamp control circuit
54 as
illustrated in FIG. 2A or the second UV lamp control circuit
54′
as illustrated in FIG. 2B so as to have the amount of light adjusted by the control
of the light-source control voltage under the control of these UV lamp control
circuits. These UV lamps
51a,
52a are of the same structure
and therefore have the same light intensity characteristics relative to the time
for which they are lit and the same electric current characteristics relative to
the amount of light of these UV lamps. Accordingly, throughout the detailed description,
which will be made hereinafter for the manner of compensation to these characteristics,
the light intensity characteristics mentioned for either UV lamp is also applied
to another UV lamp.
The printing press A of FIG. 1 further includes a main control part CONT (not
illustrated in FIG. 1; see FIGS.
2A and
2B). FIG. 2A illustrates
the arrangements of essential members such as the main control part CONT and the
first UV lamp control circuit
54 in a case where the first drying apparatus
50 is provided in the printing press A. FIG. 2B illustrates the arrangements
of essential members such as the main control part CONT and the second UV lamp
control circuit
54′ in a case where the second drying apparatus
50′
is provided in the printing press A.
The main control part CONT is connected to various units of the printing press
A, while these units are omitted in FIGS. 2A and 2B, so as to control the entire
operation of the printing press A. As illustrated in FIGS. 2A and 2B, the main
control part CONT includes a ROM
61 that stores programs and data required
for processing printing operation, a microprocessor MP that reads out data from
the ROM
61 and processes the same, a RAM
62 that temporarily stores
data required for the operation of the microprocessor MP, and an interface IF that
inputs data into the microprocessor MP and outputs data therefrom. An operation
panel OP is connected to the main control part CONT via the interface IF for input
of the information required for printing and operation information. The first UV
lamp control circuit
54 of FIG. 2A or the second UV lamp control circuit
54′ is also connected to the main control part CONT.
As illustrated in FIG. 2A, the first U-V lamp control circuit
54 is to
control drying operation applied to sheets P through the UV lamps
51a,
52a under the control of the main control part CONT. The first UV
lamp control circuit
54 includes a setting means (herein a light-amount
compensation table
54b) for setting therein a correlation between
the information relating to the time for which the UV lamp
51a,
52a
is lit (herein, the information is the time for which the UV lamp
51a,
52 is lit) and the information relating to the amount of light of the UV
lamp
51a,
52a (herein, the information is the amount
of light of the UV lamp
51a,
52a) and a light-source
control part
54a, and connects to a detection device (herein an elapsed
time detector
54c for detecting the elapsed time for which an UV
lamp is lit) for detecting information relating to the elapsed time for which the
light source is lit.
FIG. 3 is a graph illustrating an example of the light intensity characteristic
relative to the light-source control voltage in solid line. FIG. 4 is a graph illustrating
an example of the light intensity characteristics relative to the time for which
the UV lamp
51a,
52a is lit.
As illustrated in FIG. 4, the amount of light of the UV lamp
51a,
52 tends to decrease as the time for which the lamp is lit is elapsed. As
illustrated by the graph in solid line, the light source control voltage has a
relation substantially proportional to the amount of light of the UV lamp, so that
by increasing the light-source control voltage, the amount of light of the UV lamp
can be increased, while by decreasing the light-source control voltage, the amount
of light of the UV lamp can be decreased.
Accordingly, as illustrated in FIG. 4, by applying a light-source control
voltage of such a degree as to allow control of light of the UV lamp
51a,
52a to a constant amount even if the light intensity characteristics
of the UV lamp
51a,
52a is decreased as the time for
which the UV lamp is lit is elapsed, to the UV lamp
51a,
52a,
it is possible to control light of the UV lamp
51a,
52a
to a constant amount regardless of the elapsed time for which the UV lamp is
lit. The description will be hereinafter made for this control operation. The light
intensity characteristics relative to the elapsed time for which a light source
is lit can be previously obtained by a test such as a continuous lighting test
in which a light source is continuously lit, intermittent lighting test in which
light-on and light-off are repeatedly performed every a certain period of time,
or any other test.
The light-amount compensation table
54b of FIG. 2A is to store
a correlation between the time for which the UV lamp
51a,
52a
is lit and the amount of light, as illustrated in FIG.
4. More specifically,
the light-amount compensation table
54b stores a light-amount compensation
value relative to the time for which the UV lamp
51a,
52a
is lit, as described below. The table numbers 0-15 respectively correspond
to the lighting times of the UV lamps
51a,
52a, T
0-T
15,
and the amounts of light L
0-L
15 relative to the lighting times T
0-T
15
are stored.
| |
|
| |
TABLE NOS. |
0 |
1 |
2 |
. . . |
15 |
| |
|
| |
LIGHTING TIMES |
T0 |
T1 |
T2 |
. . . |
T15 |
| |
AMOUNTS OF |
L0 |
L1 |
L2 |
. . . |
L15 |
| |
LIGHT |
| |
|
The elapsed time detector
54c for detecting the elapsed time for
which an UV lamp is lit is to accumulate the time for which the UV lamp
51a,
52a is lit (a lighting time) and detect the accumulated time as an
elapsed time, and includes a timer means for measuring the lighting time of the
UV lamp
51a,
52a, a storing means for storing the lighting
time, and a calculation means for accumulating the lighting time of the UV lamp
measured by the timer means to the lighting time stored in the storing means and
again storing the thus accumulated lighting time in the storing means. The life
of the UV lamp
51a,
52a may be preset so as to allow
indication of the timing of the replacement of the lamp when the elapsed time detector
54c detects that the life of the UV lamp
51a,
52a
has been expired.
The light-source control part
54a of FIG. 2A calculates a light-source
control voltage Vx that controls light of the UV lamp
51a,
52a
to a constant amount regardless of the elapsed time for which the UV lamp
51a,
52a is lit, from a light amount Lx obtained from the preset correlation
between the lighting times: T
0-T
15 and the amounts of light: L
0-L
15
wit reference to an elapsed lighting time Tx detected at the elapsed time detector
54c. This light-source control voltage Vx can be calculated by, for
example, taking the reciprocal of the values in the correlation between the light-source
control voltage of the UV lamp
51a,
52a and the amount
of light (see the broken lines in FIG.
3). FIG. 5 illustrates the correlation
between the time for which the UV lamp
51a,
52a is
lit and the light-source control voltage that controls light of the UV lamp
51a,
52a to a constant amount regardless of the elapsed time for which
the UV lamp
51a,
52a is lit. In a specific example
with reference to FIG. 5, when the elapsed time exceeds the range of T
0
and currently lies in the range of T
1, the light of the UV lamp
51a,
52a can be controlled to a constant amount by setting the light-source
control voltage to V
1 that is greater than V
0.
In an example as illustrated in FIG. 2A, the information relating to the time
for which each UV lamp
51a,
52a is lit is the time
for which the UV lamp
51a,
52a is lit. Alternatively,
this information may be the number of sheets P, the operation time of the printing
press A or the like. In this case, the elapsed time detector
54c for
detecting the elapsed time for which a light source is lit may be replaced with
a counter for counting the number of sheets P, or an elapsed time detector that
accumulates the operation time of the printing press A and detects the accumulated
time as a detected value.
In the above example, the setting means is the light-amount compensation table
54b for storing the correlation between the time for which the UV
lamp
51a,
52a is lit and the amount of light. Alternatively,
this setting means may be a calculation means provided with a calculation formula
that can calculate an approximate correlation to the aforesaid correlation. In
this case, the approximate correlation may be calculated by this calculation formula,
using a least square approximation method based on data in a graph as illustrated
in FIG.
4.
As illustrated in FIG. 2B, the second UV lamp control circuit
54′
is to control the drying operation applied to sheets P through the UV lamps
51a,
52a under the control of the main control part CONT. This second
UV lamp control circuit
54′ includes a setting means (herein a light-amount
compensation table
54b′) for presetting of a correlation between
information relating to the value of the electric current passing through the UV
lamp
51a,
52a (herein, the information is the value
of the electric current of the UV lamp
51a,
52a) and
information relating to the amount of light of the UV lamp
51a,
52a
(herein, the information is the amount of light of the UV lamp
51a,
52a) and a light-source control part
54a′, and
connects to a detection device for detecting the information relating to the value
of the electric current (herein a UV-lamp electric current detector
54c′).
FIG. 6 is a graph illustrating an example of the electric current characteristics
relative to the amount of light of the UV lamp
51a,
52a.
As illustrated in FIG. 6, decrease in amount of light of the UV lamp
51a,
52a appears in value of the electric current passing through the
UV lamp
51a,
52a.
As described above, the light source control voltage illustrated in solid line
in FIG. 3 has a relation substantially proportional to the amount of light of the
UV lamp, so that by increasing the light-source control voltage, the amount of
light of the UV lamp can be increased, while by decreasing the light-source control
voltage, the amount of light of the UV lamp can be decreased.
Accordingly, as illustrated in FIG. 6, by applying a light-source control
voltage of such a degree as to allow control of light of the UV lamp
51a,
52a to a constant amount regardless of that the electric current
characteristics decreases due to decrease of the amount of light, to the UV lamp
51a,
52a, it is possible to control light of the UV
lamp
51a,
52a to a constant amount regardless of the
value of the electric current passing therethrough. The description will be hereinafter
made for this control operation.
The light-amount compensation table
54b′ of FIG. 2B is to
store a correlation between the value of the electric current passing through the
UV lamp
51a,
52a and the amount of light. More specifically,
the light-amount compensation table
54b′ stores a light-amount
compensation value relative to the value of the electric current passing through
the UV lamp
51a,
52a, as described below. The table
numbers
0-
15 respectively correspond to the values of the electric
current passing through the UV lamp
51a,
52a, I
0-I
15,
and the amounts of light L
0-L
15 relative to the values of the eclectic
current I
0-I
15 are stored.
| |
|
| |
TABLE NOS. |
0 |
1 |
2 |
. . . |
15 |
| |
|
| |
VALUES OF |
I0 |
I1 |
I2 |
. . . |
I15 |
| |
ELECTRIC |
| |
CURRENT |
| |
AMOUNTS OF |
L0 |
L1 |
L2 |
. . . |
L15 |
| |
LIGHT |
| |
|
The UV-lamp electric current detector
54c′ as illustrated
in FIG. 2B is herein designed to detect the value of the electric current passing
through the UV lamp
51a,
52a during the UV lamp
51a,
52a is lit.
The light-source control part
54a′ of FIG. 2B calculates
a light-source control voltage Vx that controls light of the UV-lamp
51a,
52a to a constant amount regardless of the value of the electric
current, from a light amount Lx obtained from the preset correlation between the
values of the electric current: I
0-I
15 and the amounts of light:
L
0-L
15 with reference to an electric current value Ix detected at
the UV-lamp electric current detector
54c′. As described above,
this light-source control voltage Vx can be calculated by, for example, taking
the reciprocal of the values in the correlation between the light-source control
voltage of the UV lamp
51a,
52a and the amount of light
(see the broken lines in FIG.
3). FIG. 7 illustrates the correlation between
the value of the electric current passing through the UV lamp
51a,
52a and the light-source control voltage that controls light of the
UV lamp
51a,
52a to a constant amount regardless of
the elapsed time for which the UV lamp
51a,
52a is
lit. In a specific example with reference to FIG. 7, when the value of the electric
current is decreased from I
0 and lies in the range of I
1, the light
of the UV lamp
51a,
52a can be controlled to a constant
amount by setting the light-source control voltage to V
1 that is greater
than V
0.
In an example of FIG. 2B, the setting means is the light-amount compensation
table
54b′ for storing the correlation between the value of the
electric current passing through the UV lamp
51a,
52a and
the amount of light. Alternatively, this setting means may be a calculation means
provided with a calculation formula that can calculate an approximate correlation
to the aforesaid correlation. In this case, the approximate correlation may be
calculated by this calculation formula, using a least square approximation method
based on data in a graph as illustrated in FIG.
6.
FIG. 8A is a flowchart illustrating an example of drying operation flow applied
to dry prints by the first drying apparatus
50. FIG. 8B is a flowchart illustrating
an example of a drying operation flow applied to dry prints by the second drying
apparatus
50′.
The first drying apparatus
50 as illustrated in FIGS. 1 and 2A starts
its drying operation upon receiving control command from the main control part
CONT (Step S
1). Then, the UV lamps
51a,
52a are
turned on upon receiving command (Step S
2), and during they are lit, the
elapsed time, for which the UV-lamp
51a,
52a is lit,
is detected by the elapsed time detector
54c (Step S
3). Then,
in the correlation represented in broken line of FIG. 3, the light-source control
part
54a calculates a light-source control voltage that controls
light of the UV lamp
51a,
52a to a constant amount
regardless of the elapsed time for which the UV lamp
51a,
52a
is lit, from a light amount Lx obtained from the preset correlation between
the lighting times: T
0-T
15 and the amounts of light: L
0-L
15
with reference to the elapsed time detected at the elapsed time detector
54c:
(Step S
4). The amount of light of the UV lamp
51a,
52a
is thus controlled by this control voltage to a constant amount regardless
of the elapsed time for which the UV lamp
51a,
52a is
lit (Step S
5). Then, returning to Step S
1, this process is repeatedly
performed. Then, the drying operation is finished upon receiving command to finish
the drying operation (Step S
1) or command to turn off the UV lamps
51a,
52a (Step S
2) from the main control part CONT. The second
drying apparatus
50′ as illustrated in FIGS. 1 and 2B starts its
drying operation upon receiving control command from the main control part CONT
(Step S
1′). Then, the UV lamps
51a,
52a are
turned on upon receiving command (Step S
2′), and during they are
lit, the value of the electric current passing through the UV lamp
51a,
52a is detected by the UV-lamp electric current detector
54c′
(Step S
3′). Then, in the correlation represented in broken line of
