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United States Patent |
6,181,986
|
Akira
|
January 30, 2001
|
Method of correcting transfer of a thin material and a thin material
transfer apparatus
Abstract
A transfer correcting method for a thin material transfer apparatus
includes detecting a front end of a thin material by the sensor, and
transferring the thin material from a position of the sensor, to a
processing unit, and further a reference transfer range from the
processing unit to produce a first processed thin material portion, and
transferring the thin material the reference transfer range to produce a
second processed thin material portion, calculating a first correction
value based on the reference transfer range and a measured length of the
second processed thin material portion and a second correction value based
on measured lengths of the first and second processed thin material
portions, and correcting the transfer from the sensor position to the
processing unit position, and the transfer from the processing unit
position based on based on the first and second correction values.
Inventors:
|
Akira; Toshiro (Wakayama, JP)
|
Assignee:
|
Noritsu Koki Co., Ltd. (Wakayama-ken, JP)
|
Appl. No.:
|
159968 |
Filed:
|
September 24, 1998 |
Foreign Application Priority Data
Intern'l Class: |
G05D 013/00; B41J 002/385 |
Field of Search: |
700/193,304,114,124,128
271/263,121
382/181
347/116
355/40,41
|
References Cited
U.S. Patent Documents
5093674 | Mar., 1992 | Storlie | 347/116.
|
5291225 | Mar., 1994 | Saito | 346/134.
|
5437445 | Aug., 1995 | Chang | 271/263.
|
5555181 | Sep., 1996 | Seto | 355/41.
|
5626334 | May., 1997 | Kondo | 271/121.
|
5774357 | Jun., 1998 | Hoffberg | 713/600.
|
5790921 | Aug., 1998 | Ishikura | 399/86.
|
5801814 | Sep., 1998 | Matsumoto | 355/40.
|
5875108 | Feb., 1999 | Hoffberg | 700/17.
|
5920477 | Jul., 1999 | Hoffberg | 382/181.
|
Primary Examiner: Grant; William
Assistant Examiner: Hartman, Jr.; Ronald D
Attorney, Agent or Firm: Jordan and Hamburg LLP
Claims
What is claimed is:
1. A method of correcting transfer of a thin material transfer apparatus
comprising a transfer roller which is rotated in accordance with a number
of input transfer pulses; a sensor which detects a front end of a thin
material transferred by the transfer roller; and a processing unit which
is disposed downstream from the sensor, and performs a predetermined
process on the transferred thin material, the method comprising the steps
of:
detecting a front end of a thin material by the sensor, and transferring
the thin material from a position of the sensor by a transfer pulse number
corresponding to a specified distance between the sensor and the
processing unit, and a transfer pulse number corresponding to a reference
transfer range from a position of the processing unit;
performing the process in the processing unit on the transferred thin
material, thereby obtaining a first processed thin material portion;
transferring the thin material by a transfer pulse number corresponding to
the reference transfer range;
performing the process in the processing unit on the transferred thin
material, thereby obtaining a second processed thin material portion;
calculating a first correction value for correcting a transfer error based
on the reference transfer range and a measured length of the second
processed thin material portion, and calculating a second correction value
for correcting a transfer error based on measured lengths of the first and
second processed thin material portions; and
correcting the transfer from the sensor position to the processing unit
position, and the transfer from the processing unit position based on the
first and second correction values.
2. A method according to claim 1, wherein the step of correcting the
transfer range of the thin material from the sensor position to the
processing unit position, and the transfer range of the thin material from
the processing unit position, includes the steps of:
calculating a first transfer pulse number required for transferring the
thin material from the sensor position to the processing unit position
based on the first and second correction values, the specified distance,
and a specified transfer pitch per pulse, and calculating a second
transfer pulse number required for transferring the thin material by a
predetermined range from the processing unit position based on the first
correction value, the predetermined range, and the specified transfer
pitch per pulse; and
transferring the thin material from the sensor position by a sequence of
the first transfer pulse number and the second transfer pulse number.
3. A method according to claim 2, wherein the first transfer pulse number
is calculated from an equation of {(L.sub.SP +C.sub.2)/P}.times.C.sub.1,
and the second transfer pulse number is calculated from an equation of
(L.sub.R /P).times.C.sub.1, wherein:
L.sub.SP is the specified distance between the sensor and the processing
unit,
P is the specified transfer pitch per pulse,
C.sub.1 is the first correction value,
C.sub.2 is the second correction value, and
L.sub.R is the predetermined range of the thin material transferred from
the processing unit position.
4. A method according to claim 1, wherein the first correction value is
calculated from an equation of L.sub.0 /L.sub.2, and the second correction
value is calculated from an equation of (L.sub.2 -L.sub.1), wherein:
L.sub.0 is the reference transfer range,
L.sub.1 is the measured length of the first processed thin material
portion, and
L.sub.2 is the measured length of the second processed thin material
portion.
5. A method according to claim 4, wherein the step of correcting the
transfer range of the thin material from the sensor position to the
processing unit position, and the transfer range of the thin material from
the processing unit position, includes the steps of:
calculating a first transfer pulse number required for transferring the
thin material from the sensor position to the processing unit position
based on the first and second correction values, the specified distance,
and a specified transfer pitch per pulse, and calculating a second
transfer pulse number required for transferring the thin material by a
predetermined range from the processing unit position based on the first
correction value, the predetermined range, and the specified transfer
pitch per pulse; and
transferring the thin material from the sensor position by a sequence of
the first transfer pulse number and the second transfer pulse number.
6. A method according to claim 5, wherein the first transfer pulse number
is calculated from an equation of {(L.sub.SP +C.sub.2)/P}.times.C.sub.1,
and the second transfer pulse number is calculated from an equation of
(L.sub.R /P).times.C.sub.1 , wherein:
L.sub.SP is the specified distance between the sensor and the processing
unit,
P is the specified transfer pitch per pulse,
C.sub.1 is the first correction value,
C.sub.2 is the second correction value, and
L.sub.R is the predetermined range for the thin material transferred from
the processing unit position.
7. A thin material transfer apparatus comprising:
a roller driving unit which rotates a transfer roller in accordance with a
number of input transfer pulses;
a sensor which detects a front end of a thin material transferred by the
transfer roller;
a processing unit which is disposed downstream from the sensor, and
performs a predetermined process on the transferred thin material;
a first calculator which calculates a first transfer pulse number for
transferring the thin material from a position of the sensor to a position
of the processing unit position, the first transfer pulse number being
calculated based on first and second correction values for correcting a
transfer error, the first correction value being calculated based on a
reference transfer range and a measured length of a second processed thin
material portion, the second correction value being calculated based on
measured lengths of the first and second processed thin materials portion,
the reference transfer range being a predetermined range which the thin
material is transferred from the position of the processing unit, the
first processed thin material portion being produced by transferring the
thin material from the position of the sensor by a transfer pulse number
corresponding to a specified distance between the sensor and the
processing unit after the sensor detects the front end of the thin
material, and transferring from the position of the processing unit by a
transfer pulse number corresponding to the reference transfer range,
performing the process in the processing unit, the second processed thin
material portion being produced by transferring the thin material by a
transfer pulse number corresponding to the reference transfer range,
performing the process in the processing unit on the transferred thin
material;
a second calculator which calculates a second transfer pulse number for
transferring the thin material from the processing unit position based on
the first correction value; and
a control unit which controls the roller driving unit to transfer the thin
material from the sensor position by a sequence of the first transfer
pulse number and the second transfer pulse number.
8. A thin material transfer apparatus according to claim 7, wherein the
first correction value is calculated from an equation of L.sub.0 /L.sub.2,
the second correction value is calculated from an equation of (L.sub.2
-L.sub.1), the first transfer pulse number is calculated from an equation
of {(L.sub.SP +C.sub.2)/P}.times.C.sub.1, and the second transfer pulse
number is calculated from an equation of (L.sub.R /P).times.C.sub.1,
wherein:
L.sub.0 is the reference transfer range for the processed thin material,
L.sub.2 is the measured length of the second processed thin material
portion,
L.sub.1 is the measured length of the first processed thin material
portion,
L.sub.SP is the specified distance between the sensor and the processing
unit,
P is a transfer pitch per pulse,
C.sub.1 is the first correction value,
C.sub.2 is the second correction value, and
L.sub.R is a predetermined range for the thin material.
Description
BACKGROUND OF THE INVENTION
This invention relates to a method of correcting transfer of a thin
material such as printing paper in a thin material transfer apparatus
which is applied to a photoprinting machine or the like, and also to a
thin material transfer apparatus to which the correction method is
applied.
Recently, a photoprinting machine which automatically prints a film image
or the like on printing paper is widely used. Such a photoprinting machine
has a thin material transfer apparatus comprising: a transfer roller which
transfers printing paper; a sensor which detects the front end of the
transferred thin material; and a cutter which is disposed downstream from
the sensor. Roll-like printing paper which is drawn out from a magazine or
the like is transferred to a cut position by the transfer roller, and then
cut into a predetermined length. The cut printing paper is transferred to
a print position, and then subjected to a printing process. The transfer
roller is rotated by a DC motor or the like so as to transfer printing
paper by a predetermined range in accordance with the number of transfer
pulses supplied to the motor.
In such a photoprinting machine, the transfer range of printing paper is
varied by a change of the diameter of the transfer roller which is caused
by reasons such as wear of the roller or replacement of the roller. Even
when the transfer roller is rotated by a specified transfer pulse number,
therefore, an error occurs in the distance of the cut printing paper. When
the sensor for detecting the front end of printing paper or the cutter for
cutting printing paper is replaced with another one, the mounting position
may be varied so as to change the mounting distance between the sensor and
the cutter. The transfer range of printing paper is varied also by this
change, with the result that, even when the transfer roller is rotated by
a specified transfer pulse number, an error occurs in the distance of the
cut printing paper.
When the transfer roller, the sensor, or the like is replaced with another
one, therefore, an error in transfer of printing paper is corrected in the
method described below.
First, printing paper is transferred by the transfer roller and the cutter
continuously performs two cutting operations on the printing paper,
thereby obtaining two cut sheets of printing paper (hereinafter, such a
sheet is referred to as a cut sheet). The distance of the second cut sheet
is measured and the difference between the measured distance and a
reference distance is calculated. The number of transfer pulses required
for transferring a predetermined length of the printing paper from the
position of the cutter is changed on the basis of the difference to
correct the transfer range from the cutter position. The above-mentioned
measurement of the distance of the second cut sheet is performed because
of the following reason. The first cut sheet has an error in transfer from
the cutter position, and also an error in transfer from the sensor
position to the cutter position. By contrast, the second cut sheet has
only an error in transfer from the cutter position.
Next, the printing paper is rewound so that the front end is located in
front of the sensor. Then, the printing paper is again transferred to the
downstream side. After the front end of the printing paper reaches the
sensor, the printing paper is transferred by a transfer pulse number which
corresponds to the mounting distance between the sensor and the cutter and
which has not yet been corrected. In succession, the printing paper is
further transferred from the cutter position by a transfer pulse number
which corresponds to the predetermined range and which has been corrected,
and the printing paper is cut by the cutter, thereby obtaining a third cut
sheet.
The distance of the third cut sheet is measured and the difference between
the measured distance and the reference distance is calculated. The number
of transfer pulses required for transferring the printing paper from the
sensor position to the cutter position is changed on the basis of the
difference to correct the transfer range from the sensor position to the
cutter position. In this way, the correction of the transfer range from
the sensor position to the cutter position is performed after the transfer
range from the cutter position is corrected, because, when the sequence of
the corrections is inverted, the measurement is affected by an error in
transfer from the cutter position, and hence the correction cannot be
satisfactorily performed.
In the above-described method of correcting a transfer error, two cut
sheets are required for correcting the transfer range from the cutter
position, and one further cut sheet is required for correcting the
transfer range from the sensor position to the cutter position.
Consequently, many sheets of printing paper are wasted for the correction
of the transfer error. When the transfer range from the sensor position to
the cutter position is to be corrected, the front end of printing paper
must be returned to a position in front of the sensor, and therefore the
working efficiency is lowered. When the corrections are performed in a
wrong sequence, it is forever impossible to end the correction work.
The problems are produced not only in a process of cutting printing paper,
but also in processes of cutting thin materials other than printing paper,
i.e., cut sheets made of various kinds of material such as paper, a resin,
and a metal. With respect to the contents of a process, furthermore, the
problems are produced not only in a cutting process using a cutter, but
also in processes performed by various kinds of processing units, for
example, formation of perforations in a thin material by a perforating
apparatus, or formation of an image by an image forming apparatus. In the
case where a process is performed on a wide fixed region, such as that
where an image is formed, the edge of the fixed region on the upstream
side is called a processing unit.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a method of correcting
transfer of a thin material and a thin material transfer apparatus which
have overcome the problems residing in the prior art.
According to an aspect of the invention, a method of correcting transfer of
a thin material transfer apparatus comprising a transfer roller which is
rotated in accordance with a number of input transfer pulses; a sensor
which detects a front end of a thin material transferred by the transfer
roller; and a processing unit which is disposed downstream from the
sensor, and performs a predetermined process on the transferred thin
material, the method comprises the steps of: detecting a front end of a
thin material by the sensor, and transferring the thin material from a
position of the sensor by a transfer pulse number corresponding to a
specified distance between the sensor and the processing unit, and a
transfer pulse number corresponding to a reference transfer range from a
position of the processing unit; performing the process in the processing
unit on the transferred thin material, thereby obtaining a first processed
thin material portion; transferring the thin material by a transfer pulse
number corresponding to the reference transfer range; performing the
process in the processing unit on the transferred thin material, thereby
obtaining a second processed thin material portion; calculating a first
correction value for correcting a transfer error based on the reference
transfer range and a measured length of the second processed thin material
portion, and calculating a second correction value for correcting a
transfer error based on measured lengths of the first and second processed
thin material portions; and correcting the transfer from the sensor
position to the processing unit position, and the transfer from the
processing unit position based on based on the first and second correction
values.
According to another aspect of the invention, a thin material transfer
apparatus comprises; a roller driving unit which rotates a transfer roller
in accordance with a number of input transfer pulses; a sensor which
detects a front end of a thin material transferred by the transfer roller;
a processing unit which is disposed downstream from the sensor, and
performs a predetermined process on the transferred thin material; a first
calculator which calculates a first transfer pulse number for transferring
the thin material from a position of the sensor to a position of the
processing unit position, the first transfer pulse number being calculated
based on first and second correction values for correcting a transfer
error, the first correction value being calculated based on a reference
transfer range and a measured length of a second processed thin material
portion, the second correction value being calculated based on measured
lengths of the first and second processed thin materials portion, the
reference transfer range being a predetermined range which the thin
material is transferred from the position of the processing unit, the
first processed thin material portion being produced by transferring the
thin material from the position of the sensor by a transfer pulse number
corresponding to a specified distance between the sensor and the
processing unit after the sensor detects the front end of the thin
material, and transferring from the position of the processing unit by a
transfer pulse number corresponding to the reference transfer range,
performing the process in the processing unit, the second processed thin
material portion being produced by transferring the thin material by a
transfer pulse number corresponding to the reference transfer range,
performing the process in the processing unit on the transferred thin
material; a second calculator which calculates a second transfer pulse
number for transferring the thin material from the processing unit
position based on the first correction value; and a control unit which
controls the roller driving unit to transfer the thin material from the
sensor position by a sequence of the first transfer pulse number and the
second transfer pulse number.
These and other objects, features and advantages of the present invention
will become more apparent upon a reading of the following detailed
description and accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram schematically showing a configuration of a
photoprinting machine having a thin material transfer apparatus embodying
the invention;
FIG. 2 is a block diagram showing a control configuration of the
photoprinting machine;
FIG. 3 is a flowchart illustrating an operation of renewing a correction
value; and
FIG. 4 is a flowchart illustrating an operation of correcting a transfer
error on the basis of renewed correction values.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENT OF THE INVNETION
FIG. 1 is a diagram schematically showing a configuration of a
photoprinting machine having a thin material transfer apparatus embodying
the invention. Referring to the figure, the photoprinting machine
comprises: a print processing unit 10 which is placed in the left side of
the figure; a developing unit 20 which is placed in the right side of the
figure; and a control panel 30 which is disposed on the front face of the
photoprinting machine in the left side of the figure, and which has a
start switch SW, setting keys NK such as a ten-key pad for setting various
process conditions, and the like.
The print processing unit 10 comprises: a film image projecting unit 11
which is disposed in the upper left side of the figure; a printing unit 12
which is disposed in a center portion; a printing paper supplying unit 13
on which two magazines respectively incorporating printing papers of
different sizes are mounted; a first transfer path 14 which transfers
printing paper that is selectively drawn out from one of the first and
second magazines MG.sub.1 and MG.sub.2, to the downstream side; a second
transfer path 15 which transfers the printing paper transferred from the
first transfer path 14, to the printing unit 12; and a third transfer path
16 which transfers the printing paper that has undergone a printing
process in the printing unit 12, to the developing unit 20.
The film image projecting unit 11 comprises: a negative carrier 111 which
transfers a developed negative film to an exposure position in the unit of
one frame; a light source 112 which is disposed above the negative carrier
111; a shutter 113 which is disposed below the negative carrier 111; and
an optical lens system 114 which forms a film image on the face of the
printing paper on the printing unit 12.
The printing unit 12 comprises a driving roller 121, a driven roller 122, a
transfer belt 123 which is wound around the rollers 121 and 122, and a
tension roller 124 which applies given tension to the transfer belt 123.
The printing paper supplying unit 13 is disposed above the printing unit
12, and comprises a first feed roller 131 below the first magazine
MG.sub.1, and a second feed roller 132 below the second magazine MG.sub.2.
The first and second feed rollers 131 and 132 are selectively rotated by a
roller driving unit which is not shown, so that printing paper drawn out
from the first magazine MG.sub.1 or the second magazine MG.sub.2 is sent
out to the second transfer path 15 via the first transfer path 14.
The second transfer path 15 comprises: guide plates 150 which are opposed
to each other; a transfer roller 151 which transfers the printing paper
transferred from the first transfer path 14, toward the printing unit 12;
a sensor 152 which is disposed downstream from the transfer roller 151,
and which detects the front end of the printing paper transferred by the
transfer roller 151; and a cutter 153 which is disposed downstream from
the sensor 152. The transfer roller 151 is rotated by a roller driving
unit 154 consisting of a DC motor which rotates in accordance with the
number of input transfer pulses, and other components. The sensor 152
consists of a light emitting portion 155 which is disposed on the side of
the exposure face of printing paper, and a light receiving portion 156
which is disposed on the opposite side. The cutter 153 consists of an
upper blade 157 which is disposed on the side of the exposure face of
printing paper, and a lower blade 158 which is disposed on the opposite
side. The upper blade 157 is vertically moved by a cutter driving unit 159
which consists of a DC motor and the like, so that roll-like printing
paper transferred by the transfer roller 151 is cut into a predetermined
length. The transfer roller 151, the sensor 152, the cutter 153, and the
like of the second transfer path 15 constitute the thin material transfer
apparatus to which the transfer correcting method is applied.
The third transfer path 16 comprises a plurality of transfer rollers 161
which are rotated by a roller driving unit (not shown) so as to transfer
the printing paper that has undergone a printing process in the printing
unit 12, to the developing unit 20.
The developing unit 20 comprises: a plurality of process tanks 201 filled
with processing liquid for performing a developing process on printing
paper on which an image is printed in the print processing unit 10;
transferor 202 for transferring printing paper in the process tanks 201, a
drying chamber 203 in which printing paper discharged from the process
tanks 201 is dried; and a printing paper discharging unit 204 which
sequentially discharges dried printing paper onto trays (not shown) that
are vertically arranged.
The control panel 30 comprises the start switch SW and the setting keys NK,
and also first and second input designating keys SK.sub.1 and SK.sub.2
through which a measured distance of printing paper that is cut by the
cutter 153 disposed above the second transfer path 15 is to be input.
FIG. 2 is a block diagram showing a main control configuration of the
photoprinting machine. A control unit 40 comprises a CPU 41 which performs
predetermined computing processes, a ROM 42 which stores predetermined
programs, RAMs 43 which temporarily store process data, and EEPROMs 44
which store correction values for correcting a transfer error, and
controls the operations of the whole of the photoprinting machine in
accordance with the predetermined programs. The CPU 41 has functions of
first correction value calculator 411, second correction value calculator
41.2, first transfer pulse number calculator 413, and second transfer
pulse number calculator 414 which will be described later.
Specifically, the CPU 41 receives signals from the start switch SW, the
first and second input designating keys SK.sub.1 and SK.sub.2, the setting
keys NK, the sensor 152 for detecting the front end of printing paper, and
other various sensors SE, and, in response to these signals, controls the
negative carrier 111, the shutter 113, and the optical lens system 114 of
the film image projecting unit 11; the driving roller 121 of the printing
unit 12; the first and second feed rollers 131 and 132 of the printing
paper supplying unit 13; the roller driving unit 154 of the transfer
roller 151, and the cutter driving unit 159 of the cutter 153 in the
second transfer path 15; the transfer rollers 161 of the third transfer
path 16; the transferor 202 of the developing unit 20; etc.
The thus configured photoprinting machine generally operates in the
following manner. When the start switch SW is turned ON, a negative film
is transferred in the unit of one frame by the negative carrier 111 of the
film image projecting unit 11, and film images are sequentially projected
onto the printing unit 12.
Roll-like printing paper is gradually drawn out from the magazine MG.sub.1
(or MG.sub.2) of the printing paper supplying unit 13, and then cut into a
predetermined length by the cutter 153 so as to be formed as cut sheets.
The cut sheets are sequentially transferred onto the printing unit 12. The
operation of cutting the printing paper is performed in the following
manner. First, after the front end of the roll-like printing paper drawn
out from the magazine MG.sub.1 (or MG.sub.2) reaches the sensor 152, the
printing paper is transferred by a predetermined transfer pulse number
from the position of the sensor 152 to the position of the cutter 153, and
then by a predetermined range from the position of the cutter 153 by a
predetermined transfer pulse number. Thereafter, the printing paper is cut
by the cutter 153 into a cut sheet. The transfer of the cut sheet onto the
printing unit 12 is performed in synchronization with the transfer of each
frame of the negative film in the film image projecting unit 11.
The printing paper which is transferred to the printing unit 12 is
subjected to a printing process by projecting an image from the film image
projecting unit 11, and transferred to the downstream side by the transfer
belt 123, and then to the developing unit 20 by the third transfer path
16. The printing paper which is transferred to the developing unit 20 is
sent into the process tanks 201 so as to be subjected to a developing
process. The printing paper which has undergone the developing process is
transferred into the drying chamber 203 to be dried. The printing paper
which has undergone the drying process is discharged to the printing paper
discharging unit 204.
A correction operation for correcting a distance error in the transfer
direction of a cut sheet will be described with reference to flowcharts of
FIGS. 3 and 4. Such a distance error occurs when the transfer roller 151
of the second transfer path 15 is replaced with another one, or when the
sensor 152 or the cutter 153 is replaced with another one. FIG. 3 is a
flowchart illustrating an operation of renewing the correction value for
correcting a distance error of a cut sheet, and FIG. 4 is a flowchart
illustrating an operation of correcting the transfer range of printing
paper on the basis of the renewed correction values.
Referring to FIG. 3, when a given setting key NK is pressed to instruct the
apparatus to perform the correction operation, the printing paper is
rewound so that the front end of the printing paper is located in upstream
from the sensor 152. The first correction value for correcting an error in
transfer from the position of the cutter 153 (i.e., the correction value
for correcting a transfer error which is caused by variation of the
diameter of the transfer roller 151), and the second correction value for
correcting an error in transfer from the position of the sensor 152 to
that of the cutter 153 (i.e., the correction value for correcting a
transfer error which is caused by variation of the mounting distance
between the sensor 152 and the cutter 153) are initialized. Thereafter,
the printing paper is transferred toward the sensor 152 by the transfer
roller 151 (step S1). It is then judged whether the front end of the
printing paper reaches the position of the sensor 152 or not (step S3). If
the front end of the printing paper reaches the position of the sensor 152
(YES in step S3), the printing paper is transferred from the position of
the sensor 152 by a sequence of a transfer pulse number corresponding to a
specified distance between the sensor 152 and the cutter 153, and a
transfer pulse number corresponding to a reference transfer range from the
position of the cutter 153 (step S5).
The specified distance between the sensor 152 and the cutter 153 is not a
measured distance but a distance specified in the design of the machine.
The reference transfer range from the position of the cutter 153
corresponds to a reference distance (for example, 2,000 mm) in the
transfer direction of a cut sheet which is obtained for correcting a
transfer error. The transfer pulse numbers are values which are
respectively obtained by dividing the specified distance between the
sensor 152 and the cutter 153, and the reference transfer range from the
position of the cutter 153 (i.e., the reference distance of a cut sheet)
by a pitch specified in the design of the machine which equals to a
transfer distance produced by one pulse (hereinafter, referred to as a
specified transfer pitch per pulse).
Next, the printing paper transferred in step S5 is cut by the cutter 153 so
that a first cut sheet is formed (step S7). Thereafter, the printing paper
is transferred from the position of the cutter 153 by the transfer pulse
number corresponding to the reference transfer range (step S9), and then
cut by the cutter 153 so that a second cut sheet is formed (step S11). The
transfer pulse number also is a value which is obtained by dividing the
reference transfer range by the specified pitch in the same manner as
described above.
The distances in the transfer direction of the first and second cut sheets
are measured. The obtained values (measured values) are respectively
stored in RAMs 43 of the control unit 40 (the embodiment has plural RAMs
43). Specifically, with respect to the first cut sheet, the measured value
is stored in one of the RAMs 43 (first storage portion) by pressing the
first input designating key SK.sub.1 of the control panel 30 and then
inputting the measured value through the setting keys NK, and, with
respect to the second cut sheet, the measured value is stored in another
one of the RAMs 43 (second storage portion) by pressing the second input
designating key SK.sub.2 of the control panel 30 and then inputting the
measured value through the setting keys NK. The first input designating
key SK.sub.1 and the setting keys NK form first inputting device, and the
second input designating key SK.sub.2 and the setting keys NK form second
inputting device. Alternatively, the first and second storage portions may
be configured by the same storage portion.
When a given setting key NK (instruction key) is then pressed, the first
correction value (correction coefficient) C.sub.1 for correcting the error
in transfer from the position of the gutter 153, and the second correction
value C.sub.2 for correcting the error in transfer from the position of
the sensor 152 to that of the cutter 153 are calculated (step S13).
Specifically, in response to the depress of the instruction key, the
measured length of the second cut sheet is read out from the RAM 43, and
the first correction value C.sub.1 is calculated by the first correction
value calculator 411. On the other hand, the measured lengths of the first
and second cut sheets are read out from the RAMs 43, respectively, and the
second correction value C.sub.2 is calculated by the second correction
value calculator 412.
The first correction value C.sub.1 is calculated from an equation of
L.sub.0 /L.sub.2 which is stored in the ROM 42, and the second correction
value C.sub.2 is calculated from an equation of (L.sub.2 -L.sub.1) which
is stored in the ROM 42. In the equations, L.sub.0 is the reference
transfer range from the position of the cutter 153, L.sub.1 is the
measured length of the first cut sheet, and L.sub.2 is the measured length
of the second cut sheet. The reference transfer range L.sub.0 (as
described above, for example, 2,000 mm) is previously stored in the ROM
42, and read out therefrom at the same time when the measured length of
the cut sheet is read out from the RAM 43. The calculated first and second
correction values C.sub.1 and C.sub.2 are displayed on a display device
(not shown) which is disposed in the control panel 30.
When the given setting key NK (instruction key) is then pressed, the first
correction value C.sub.1 is stored in one of the EEPROMs 44 (third storage
portion) (the embodiment has plural EEPROMs 44), and the second correction
value C.sub.2 is stored in another one of the EEPROMs 44 (fourth storage
portion), thereby renewing the correction values (step S15).
Alternatively, the third and fourth storage portions may be configured by
the same storage portion.
When the first and second correction values C.sub.1 and C.sub.2 are renewed
as described above, the printing paper is correctly cut into the
predetermined length in the next step of the printing process of the
photoprinting machine while the transfer error is corrected, and then
transferred to the printing unit 12. Specifically, referring to FIG. 4, a
first transfer pulse number P.sub.1 required for transferring the printing
paper from the position of the sensor 152 to the position of the cutter
153 is calculated by the first transfer pulse number calculator 413 by
using the first and second correction values C.sub.1 and C.sub.2, and a
second transfer pulse number P.sub.2 required for transferring the
printing paper by a predetermined range from the position of the cutter
153 is calculated by the second transfer pulse number calculator 414 by
using the first correction value C.sub.1 (step S21).
The first transfer pulse number P.sub.1 is calculated from an equation of
{(L.sub.SP +C.sub.2)/P}.times.C.sub.1 which is stored in the ROM 42, and
the second transfer pulse number P.sub.2 is calculated from an equation of
(L.sub.R /P).times.C.sub.1 which is stored in the ROM 42. In the
equations, L.sub.SP is the specified distance between the sensor 152 and
the cutter 153, P is the specified transfer pitch per pulse, C.sub.1 is
the first correction value, C.sub.2 is the second correction value, and
L.sub.R is the distance of a required cut sheet. The values of L.sub.SP
and P are previously stored in the ROM 42. When the first and second
transfer pulse numbers P.sub.1 and P.sub.2 are to be calculated, the first
and second correction values C.sub.1 and C.sub.2 are read out from the
EEPROMs 44, and L.sub.SP and P are read out from the ROM 42.
Next, the printing paper is transferred to the downstream slide from the
position of the sensor 152 by a sequence of the first transfer pulse
number P.sub.1 and the second transfer pulse number P.sub.2 (step S23),
and then cut by the cutter 153 (step S25). As a result, a transfer error
occurring when the transfer roller 151 of the second transfer path 15 is
replaced with another one, or when the sensor 152 or the cutter 153 is
replaced with another one is corrected and a cut sheet of a required
distance is obtained.
When plural cut sheets are to be continuously obtained, the second transfer
pulse number required for transferring the printing paper by the
predetermined range from the position of the cutter 153 is calculated at
each transfer by the second transfer pulse number calculator 414 by using
the first correction value C.sub.1. The printing paper is transferred to
the downstream side by the respective second transfer pulse numbers, and
sequentially cut by the cutter 153. It is a matter of course that the
calculated first and second transfer pulse numbers may be previously
stored in the EEPROMs 44 and the like and the pulse numbers may be read
out at each transfer of the printing paper from the EEPROMs 44 and the
like.
The first and second correction values are calculated by using the measured
length of the second cut sheet, and the error in transfer from the
position of the sensor 152 to that of the cutter 153, and the error in
transfer from the position of the cutter 153 are corrected by using the
first and second correction values. Therefore, a loss of the printing
paper in correction of a transfer error can be suppressed as much as
possible. Furthermore, unlike the prior art, it is not required to obtain
a third cut sheet after the printing paper is rewound so that the front
end of the printing paper is located in upstream from the sensor 152.
Therefore, the working efficiency for the correction can be effectively
enhanced.
In the embodiment, the measured lengths of the first and second cut sheets
are stored in the internal storage portion, the measured lengths are read
out from the storage portion, and the first and second correction values
C.sub.1 and C.sub.2 are internally calculated. Alternatively, the measured
lengths of the cut sheets may not be stored in the internal storage
portion, the first and second correction values C.sub.1 and C.sub.2 may be
calculated by an external electronic calculator or the like by using the
measured lengths of the cut sheets, and the first and second correction
values C.sub.1 and C.sub.2 which are externally calculated may be input to
the control unit 40 of the photoprinting machine so as to be stored in the
EEPROMs 44 and the like.
In the embodiment, the first correction value C.sub.1 is calculated from
the equation of L.sub.0 /L.sub.2. Alternatively, the first correction
value may be calculated from an equation of L.sub.2 /L.sub.0. In the
alternative, the first transfer pulse number is calculated from an
equation of {(L.sub.SP +C.sub.2)/P}.times.(1/C.sub.1), and the second
transfer pulse number is calculated from an equation of (L.sub.R
/P).times.(1/C.sub.1).
In the embodiment, the first and second correction values C.sub.1 and
C.sub.2 are renewed when the transfer roller 151, the sensor 152, the
cutter 153, or the like is replaced with another one. The timing of the
renewal is not restricted to the replacement of the transfer roller 151 or
the like. For example, the first and second correction values C.sub.1 and
C.sub.2 may be calculated when the thin material transfer apparatus is
assembled or overhauled, and a transfer error may be corrected by using
the calculated first and second correction values C.sub.1 and C.sub.2.
In the embodiment, the method is applied to a thin material transfer
apparatus which transfers and cuts printing paper. The method may be
applied to thin material transfer apparatuses for cutting thin materials
other than printing paper, i.e., thin materials made of various kinds of
material such as paper, a resin, and a metal. With respect to the contents
of a process, furthermore, the process is not restricted to a cutting
process using a cutter, and the method may be similarly applied to
processes performed by various kinds of processing units, for example,
formation of perforations in a thin material by a perforating apparatus,
or formation of an image by an image forming apparatus. Therefore, a thin
material which is cut into a predetermined length, that in which
perforations are formed, or the like is called a processed thin material,
and a cutter, a perforating apparatus, or the like is called a processing
unit.
As described above, after the front end of the thin material transferred by
the transfer roller is detected by the sensor, the thin material is
transferred to the downstream side from a position of the sensor by a
transfer pulse number corresponding to a specified distance between the
sensor and the processing unit, and from a position of the processing unit
by a transfer pulse number corresponding to a reference transfer range,
and a predetermined process is then performed in the processing unit on
the transferred thin material, thereby obtaining a first processed thin
material. In succession, the thin material is transferred to the
downstream side by a transfer pulse number corresponding to the reference
transfer range, and the predetermined process is performed in the
processing unit on the transferred thin material, thereby obtaining a
second processed thin material. A first correction value for correcting a
transfer error is calculated by using the reference transfer range and a
measured length of the second processed thin material, and a second
correction value for correcting a transfer error is calculated by using
measured lengths of the first and second processed thin materials.
Thereafter, the transfer of the thin material from the sensor position to
the processing unit position, and the transfer of the thin material from
the processing unit position are controlled based on the first and second
correction values.
The first correction value is calculated from an equation of L.sub.0
/L.sub.2, the second correction value is calculated from an equation of
(L.sub.2 -L.sub.1), and a transfer range of the thin material from the
sensor position to the processing unit position, and a transfer range of
the thin material from the processing unit position are calculated by
using the first and second correction values.
Further, a first transfer pulse number required for transferring the thin
material from the sensor position to the processing unit position is
calculated by using the first and second correction values, the specified
distance, and a specified transfer pitch per pulse, a second transfer
pulse number required for transferring the thin material by a
predetermined range from the processing unit position is calculated by
using the first correction value, the predetermined range, and the
specified transfer pitch per pulse, and the thin material is transferred
from the sensor position by the first transfer pulse number and the second
transfer pulse number.
Further, the first transfer pulse number is calculated from an equation of
{(L.sub.SP +C.sub.2)/P}.times.C.sub.1, the second transfer pulse number is
calculated from an equation of (L.sub.R /P).times.C.sub.1, and the thin
material is transferred by the first and second transfer pulse numbers.
The first correction value for correcting a transfer error is calculated by
using a reference transfer range and a measured length of a second
processed thin material, the second correction value for correcting a
transfer error is calculated by using measured lengths of first and second
processed thin materials, and the transfer of the thin material from a
sensor position to a processing unit position, and that of the thin
material from the processing unit position are corrected by using the
calculated first and second correction values. Therefore, a loss of the
thin material in correction of a transfer error can be suppressed as much
as possible, and the working efficiency for the correction can be
effectively enhanced.
Also, the thin material transfer apparatus is provided with: a first
calculator for calculating a first transfer pulse number required for
transferring a thin material from a sensor position to a processing unit
position, by using a first and second correction values and the like, the
first correction value being used for correcting an error in transfer from
the processing unit position and calculated by using a measured length of
a second processed thin material, the second correction value being used
for correcting an error in transfer from the sensor position to the
processing unit position and calculated by using measured lengths of first
and second processed thin materials; a second calculator for calculating a
second transfer pulse number required for transferring the thin material
by a predetermined range from the processing unit position, by using the
first correction value and the like; and a control unit for controlling a
roller driving unit so as to transfer the thin material from the sensor
position by a sequence of the first transfer pulse number and the second
transfer pulse number. Therefore, it is possible to realize an apparatus
in which a loss of the thin material in correction of a transfer error can
be suppressed as much as possible, and the working efficiency for the
correction can be effectively enhanced.
Although the present invention has been fully described by way of example
with reference to the accompanying drawings, it is to be understood that
various changes and modifications will be apparent to those skilled in the
art. Therefore, unless otherwise such changes and modifications depart
from the scope of the present invention, they should be construed as being
included therein.
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