U.S. patent number 3,653,322 [Application Number 04/847,611] was granted by the patent office on 1972-04-04 for register indicating system.
This patent grant is currently assigned to Harris-Intertype Corporation. Invention is credited to James Ivor Richardson.
United States Patent |
3,653,322 |
Richardson |
April 4, 1972 |
REGISTER INDICATING SYSTEM
Abstract
Multi-unit machine for operating on sheet material in web form
or in the form of individual sheets with the operations performed
by each unit to be in precise registry with the operations
performed by the other units. Each unit applies a register mark to
the sheet material which has a fixed position relative to the
operation of the unit on the sheet material. The register marks are
scanned as a group to provide output signals for checking the
timing of the units. The output signals are pulses which are
combined to provide a predetermined pulse pattern when the units
are in registry and different pulse patterns when one or more of
the units is out of registry. A cathode ray tube is utilized to
display the pulse patterns.
Inventors: |
Richardson; James Ivor
(Montville, NJ) |
Assignee: |
Harris-Intertype Corporation
(Cleveland, OH)
|
Family
ID: |
25301052 |
Appl.
No.: |
04/847,611 |
Filed: |
August 5, 1969 |
Current U.S.
Class: |
101/248; 226/3;
101/181; 226/15 |
Current CPC
Class: |
B41F
33/02 (20130101) |
Current International
Class: |
B41F
33/02 (20060101); B41F 33/00 (20060101); B41f
013/24 () |
Field of
Search: |
;101/181,248 ;250/219DR
;226/100 ;340/146.3 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Pulfrey; Robert E.
Assistant Examiner: Suter; R. E.
Claims
What is claimed is:
1. A method of checking the register of images applied to sheet
material passing through a plurality of N units of a multi-unit
printing apparatus with the images printed by each unit to be in
precise registry with the images printed by the other units,
applying a register marking to the material at each of said units
with the register marking having a predetermined fixed position
relative to the image applied by the unit to the material with the
markings applied by the units when the units are in precise
registry with each other constituting a group of markings having a
predetermined spacing relative to each other, subsequently sensing
different numbers of register markings of a said group at each of a
plurality of sensing locations along the path of movement of the
material as each of the markings move in sequence past each of the
sensing locations with the sensing locations being spaced from each
other in such a manner that different numbers of said markings of a
group arrive at said sensing locations in sequence and each marking
of a group is sensed a plurality of different times with successive
markings being sensed simultaneously at said plurality of sensing
locations when the units are in registry to provide an output
signal each time one or more register markings is sensed, using the
signals derived from a sequential sensing of different numbers of
markings of a group passing said sensing locations to signal the
registry of the images and thereby the timing of the printing units
relative to each other.
2. A method as defined in claim 1 wherein said signals are pulse
signals, and wherein signals derived from a simultaneous sensing of
said markings are combined to provide a combined pulse output for
indicating registry.
3. A method as defined in claim 2 wherein the sensing of the first
one of a group of register markings arriving at said sensing
locations is used to initiate a display apparatus for displaying
the combined pulses and their timed relationship with respect to
each other with the number of pulses which are displayed each time
a group passes said sensing locations being one less than twice the
number of markings in a group.
4. A method as defined in claim 3 wherein there are N units and the
marking of each unit is sensed N times.
5. A method as defined in claim 1 wherein the images of each
printing unit are printed from printing plates and the register
markings are on the printing plates of each unit.
6. A method as defined in claim 1 wherein the register markings are
printed with equal spacing between the adjacent markings of a group
when the units are in registry.
7. In a printing apparatus having a plurality of printing units
through which sheet material to be printed passes, each of said
units having an image carrying member which carries the image to be
printed by the unit and each of said image carrying members having
as part of the image carried thereby a register mark which is
located in a predetermined position with respect to the image, the
images printed by the individual units being superimposed on each
other and the register marks on the image carrying members of the
units being located on the image carrying member so that the
register marks are printed adjacent the superimposed image along an
imaginary line which extends lengthwise of the sheet material with
the register marks having a predetermined spacing relative to each
other when the units are printing in precise registry with each
other, the register marks consisting of one mark for each unit as
sheet material passes therethrough constituting a group of marks,
sensing means comprising a plurality of sensing devices, one for
each unit, located at respective locations along the path of travel
of the sheet material with the sensing devices being spaced from
each other by said predetermined spacing whereby each of said marks
pass each of said devices in sequence and are sensed by each said
device to provide an output signal in response to each mark with
successive marks being sensed simultaneously by successive sensing
devices when said units are printing in precise registry with each
other, and electrical means responsive to said output signals
generated by one group of marks passing all of said devices for
signaling the register condition and thereby the timing of said
units.
8. A printing apparatus as defined in claim 7 wherein said signals
are pulses and said electrical means comprises circuit means for
summing the pulse outputs from said devices.
9. An apparatus as defined in claim 8 wherein said electrical
circuit means comprises a cathode ray tube for displaying said
summed output and a sweep circuit activated in response to a pulse
output signal from the sensing device first responsive to a
register mark of a group of register marks.
10. An apparatus as defined in claim 8 wherein said electrical
means comprises a cathode ray tube for displaying said summed
pulses.
11. An apparatus as defined in claim 10 wherein said electrical
means includes means responsive to the speed of the apparatus for
maintaining the summed pulses in positions on the tube which are
independent of the speed of the material moving through the
apparatus.
12. A method of checking the registry of a plurality of N units
operating for performing operations in sequence on material passing
through the units, applying a respective register marking to the
material with each of said units to thereby provide a group of
markings for indicating the registry of the units, sensing the time
of arrival of the markings as the markings arrive at a plurality of
sensing locations corresponding in a number to the number of units
with the marking applied by each unit being sensed a plurality of
times in combination with different numbers of markings of said
group of markings to provide a group of electrical signals which
are analyzable to determine registry.
13. A method of checking the register of operations performed in
sequence on material passing through a plurality of units of a
multi-unit apparatus with the operations performed by each unit to
be in precise registry with the operations performed by the other
units, said method including the steps of applying a plurality of
spaced apart register marks to the material as the material passes
through the plurality of units of the multi-unit apparatus with the
spacing between the marks varying as a function of variations in
the registry operations performed by the units, generating a
plurality of pulses having a time relationship which is a function
of the spatial relationship between the register marks and the
registry of the operations performed by the units, combining at
least some of said pulses to form a combined pulse having a
characteristic which varies as a function of variations in the time
relationship between the combined pulses and which is indicative of
the registry between the units, said step of combining at least
some of said pulses includes the steps of combining a plurality of
pulses to form a plurality of combined pulses each of which has a
characteristic which varies as a function of the time relationship
between the pulses which were combined to form it, forming a series
of pulses which includes a plurality of said combined pulses and
which has predetermined characteristics which vary with variations
in registry between the units in a manner which is indicative of
which unit of the plurality of units is out of registry upon a
variation in registry, and sensing the predetermined
characteristics of the series of pulses to determine which unit of
the plurality of units is out of registry upon a variation in
registry.
14. A method of checking the register of operations performed in
sequence on material passing through a plurality of units of a
multi-unit apparatus with the operations performed by each unit to
be in precise registry with the operations performed by the other
units, applying a register mark to the material at each of said
units with the marks applied by the units when the units are in
precise registry with each other constituting a group of marks
having a predetermined spacing relative to each other, sensing each
of the register marks of a group at each of a plurality of sensing
locations along the path of movement of the material after said
operations have been performed and as the marks move in sequence
past each of the sensing locations with the sensing locations being
spaced by said predetermined spacing with successive marks being
sensed simultaneously at successive said sensing locations when the
units are in registry, establishing a signal in response to each
sensing of the register marks of a group, and signaling the
registry of the operations and thereby the timing of the units
relative to each other in dependence on the relationship to each
other of the marks of a group.
15. A method as defined in claim 14 wherein the marks cause a pulse
signal at each location and in which the pulse signals are combined
to provide output pulses which indicate the registry and thereby
the timing of the units.
Description
The present invention relates to an apparatus and method for
ascertaining the registrations of operations being performed on
sheet material in the form of a web or individual sheets by a
plurality of machine units through which the sheet material moves
in sequence. The invention is particularly useful in a printing
press in which each of the units applies an image to the sheet
material moving through the unit with the image being repeated on
succeeding material to form successive images as the material
passes continuously through the machine. Each of the images printed
by a unit is to bear a predetermined relationship with respect to
the images printed by the other units. For example, the printing
apparatus may be a multi-color lithographic printing press in which
each printing unit prints a respective component color image of a
desired print onto the web or sheet. The component color images
printed by the units are superimposed on each other to produce the
desired print and must be in precise registry to produce a
high-quality print.
In the practice of the present invention, each printing unit
applies a register mark to the sheet material with the register
mark having a predetermined fixed position with respect to the
image printed by the unit. In a case of a printing press, the
register mark may be a part of a printing plate so that it is
always in a predetermined position with respect to the image
carried by the plate regardless of the position of the plate on the
plate cylinder and regardless of the angular position of the
printing unit relative to the other units.
The marks printed by the different units of the press corresponding
to one image provide a group of register marks which are, when the
images are properly registered, spaced from each other along a line
extending in the direction of movement of the web or sheets through
the printing press. The register marks of a group preferably all
have the same spacing from their adjacent marks, with the spacing
of each mark from the first mark being a multiple of the basic
spacing between marks. The marks are preferably in the order of the
printing units with the first register mark of a group
corresponding to the first printing unit. If an image being printed
by one of the units is not in registry, the spacing of its register
mark from the other register marks will be different from the
predetermined spacing which indicates register.
In accordance with a specific form of the invention, the register
marks are sensed by a plurality of sensing devices which correspond
in number to the number of units to be checked for register. The
sensing devices are spaced from each other along the web or sheet
path in accordance with the predetermined spacing between register
marks of a group when the images being printed are in register. The
outputs of the sensing devices are pulse signals generated by the
movement of the marks past the sensing device. These pulse signals
are combined so that when the units are in register, the pulse
signals will increase and then decrease in magnitude as a group of
register marks passes the sensing devices. In a lithographic press,
a group of register marks comprises a mark printed by each unit as
it prints an image. As a group of such marks corresponding to one
final image passes the sensing devices, the first sensing device
will have output signals in sequence in response to the arrival of
the successive register marks and the other sensing device will
have corresponding pulse output signals, but the output signals
will be phase displaced by the time required for the register marks
to move between the sensing devices. Consequently, as a group of
register marks moves by the sensing devices, the first sensing
device will have an output and this will be the sole output from
the sensing devices. As the first register mark moves opposite to
the second sensing device, the second register mark will be
opposite the first sensing device and the combined output will have
a magnitude which is the sum of the output signals from both the
first and second sensing devices. When the first register mark
moves opposite the third sensing device, the second register mark
will be opposite the second sensing device and the third register
mark will be opposite the first sensing device and the combined
output will be a signal which is three times the magnitude of the
initial signal. Similarly, as the number of register marks opposite
the sensing devices increases, the magnitude of the combined pulse
signals will increase, while after the first register mark passes
the last sensing device, the combined pulse signal will start to
decrease in magnitude. The magnitudes and the timing of the
combined pulse signals from the sensing devices are utilized to
indicate the registry of the images printed by the units.
An object of the present invention is to provide a new and improved
system for checking the registry of machine units which operate in
sequence on sheet material in which each unit applies a register
mark which has a fixed relationship with respect to the operation
performed by the unit on the material and the register marks are
read by register mark sensing devices whose outputs are analyzed as
a group to obtain an indication of the registry of the units.
A further object of the present invention is to provide a new and
improved system for checking the registry of printing units, or
other units for performing an operation on sheet material, with
respect to each other in which an operator may view pulse signals
whose patterns and form indicate when the units are in register and
if the units are out of register the nature of the misregister.
Further objects and advantages of the present invention will be
apparent from the following description of the specific form of the
preferred embodiment thereof made in reference to the accompanying
drawings and forming a part of this specification for all subject
matter disclosed therein and in which
FIG. 1 is a diagrammatic view of a printing press embodying the
present invention;
FIG. 2 is a fragmentary showing of a printing plate used on one of
the printing units of FIG. 1;
FIG. 3 is a sectional view taken approximately along line 3--3 of
FIG. 1;
FIG. 4 is a view looking from approximately along line 4--4 of FIG.
3; and
FIG. 5 is a series of graphic displays illustrating output signals
from the system.
The present invention can be used in and with various types of
machines which have a plurality of units which are to operate on
sheet material with the operation performed by the units to have a
precise relationship on the material with respect to each other,
e.g. printing presses and cutter and creasers operating with a
plurality of units.
Referring to the drawings, the invention is illustrated as embodies
in a four-color lithographic printing press 10 which is shown
schematically in FIG. 1. The printing press includes four
lithographic printing units 12, 13, 14 and 15 with each of the
printing units having an impression cylinder 16, a blanket cylinder
17 and a plate cylinder 18. Printing presses of the type
illustrated schematically in FIG. 1 are well known to those skilled
in the art. It will be understood that each of the printing units
includes the conventional dampening and inking mechanism and that
the units print onto sheet material, such as a web 20 which is
supplied from a web supply roll and which is delivered by
conventional delivery means associated with the printing press.
In a multi-color lithographic printing press of the type shown,
each printing unit prints a single-color image which is a color
component of the final image to be printed onto the web. The color
image printed by each of the printing units 12-15 must register
precisely with the color images printed by the other printing units
if the complete printed image is to be a high-quality print. It is
understood that as the press operates, the images from the four
printing units are superimposed on each other to make the final
image and the final image is repeated along the length of the web
once for each revolution of the printing units.
In a lithographic printing press, a plate carrying the image to be
printed is mounted on the plate cylinder by plate attaching means
located in the gap of the plate cylinder. In accordance with a
specific form of the preferred embodiment of the present invention,
the plates of each of the printing units have a register mark 22
thereon which is outside of the component image and along one side
of the plate as illustrated in FIG. 2. The mark is in a fixed
predetermined position with respect to the leading edge of the
printing plate so that when the image is printed, a register mark
22a will also be printed onto the web, but outside of the picture
or print area, at a fixed distance from the leading edge of the
plate along one side of the web. The register marks for the
printing units 13, 14 and 15 are located from the leading edge of
the plate at an increasingly greater distance. That is, the
register mark on the plate on the unit 13 is at a greater distance
from the leading edge of the plate than the register mark on the
plate for the printing unit 12 and the register mark on the
printing unit 14 is at a greater distance from the leading edge
than the register mark on the printing plate for unit 13, etc. The
spacings of the register marks from the leading edges of the plate
are such that when the marks are printed onto the web, they are
spaced equally along the length of the web when the images printed
by the printing units are in precise registry along the length of
the web. The register marks are short lines extending in a
transverse direction across the web.
As the web leaves the last printing unit 15, the register marks are
sensed by a sensing means 30 comprising sensing devices
corresponding in number to the number of printing units in the
press, four in the illustrated embodiment. The sensing devices are
shown in FIG. 3 and are designated by the reference characters 32a,
32b, 32c and 32d. The sensing devices 32a . . . 32d may be
conventional photo detector devices for reading register marks on a
web and, in the illustrated embodiment, have been shown as being
responsive to light from a lamp 34 which extends along the web
adjacent the sensing devices 32a . . . 32d. The sensing means
includes a reflector 35 for directing the light onto the web, so
that the light is reflected from the web to the sensing devices 32a
. . . 32d. The sensing devices 32a . . . 32d each view the web
through a respective slit 38 in a masking member 39. When a
register mark passes the respective slit, the light received by the
sensing device is diminished substantially to provide an output
signal. The signals from conventional photo detectors are normally
negative going signals. These signals may be shaped in conventional
pulse shaping circuits (not shown) and then summed in a summing
amplifier 40 whose output has a magnitude which is dependent upon
the sum of the magnitude of the inputs thereto. The signals from
the sensing devices may be inverted by the pulse shapers or by the
summing amplifier 40 to provide a positive going signal from the
summing amplifier 40. When all four register marks of a group,
assuming the marks are in their proper relationship, are opposite
the reading slits for the sensing devices 32a . . . 32d, the output
of the amplifier 40 is at a maximum and is proportionately less
when three marks, two marks, or one mark is opposite to the reading
slits. Consequently, as the first register mark arrives at the
sensing device 32a, a minimum pulse signal will appear at the
output of amplifier 40. If the first two units have proper
registry, a pulse signal of approximately twice that magnitude will
occur when the first register mark arrives at the photocell sensing
device 32b and the second register mark at the photocell sensing
device 32a. Similarly, the amplifier output will be at a third
level and at a maximum level as 3 and 4 register marks respectively
are opposite to the sensing devices 32a . . . 32d. Since it takes a
period of time for the register marks to travel between the reading
slits for the sensing devices 32a . . . 32d, the outputs from the
amplifier 40 will be spaced in time, assuming the units are in
registry with each other, and the output from the amplifier 40 will
be a series of pulse signals.
In accordance with the invention, the output of the amplifier 40 is
applied to a vertical deflection control circuit 42 (FIG. 1) for a
cathode ray tube 43. Also, the signal from the sensing device 32a
is applied to a horizontal sweep circuit 44 to initiate a
horizontal sweep of the beam. The cathode ray tube 43 will display
the pulse signals as shown in (a) of FIG. 5 when the units are in
register. As shown in (a) of FIG. 5, the pulse signals on the
cathode ray tube progressively increase from a minimum pulse signal
designated by the reference character 45 which occurs when the
first registration mark is opposite the sensing device 32a to a
maximum pulse signal 47 which occurs when all four register marks
are opposite to the sensing devices 32a . . . 32d to a minimum
pulse signal 49 when the last register mark is opposite the sensing
device 32d.
Illustrative pulse patterns are shown in FIG. 5. Patterns (b) and
(c) of FIG. 5 represent typical pulse patterns when unit No. 1 is
respectively advanced or retarded, (d) and (e) represent typical
pulse patterns when unit No. 2 is advanced or retarded, (f) and (g)
represent typical pulse patterns when unit No. 3 is advanced or
retarded while (h) and (i) represent patterns for unit No. 4. From
the examination of the patterns it will be seen that it can be
readily determined when one unit is advanced or retarded. If only
one unit is advanced or retarded, the pulse initiated by the mark
printed by the unit when it reaches the first slit will cause the
trailing or leading edge of the combined pulses to be respectively
advanced or retarded depending upon whether the unit is early or
late in printing. If the distortion first occurs in the third or
fourth pulse, the pulse where the first distortion occurs indicates
the unit which is out of register and the shifting of the leading
edge of the pulse forwardly in time or the trailing edge later in
time will indicate whether the unit is advanced or retarded. When
the distortion appears in the second pulse for the first time, it
is not always clear from the second pulse whether the No. 1 unit is
retarded or advanced or the No. 2 unit is retarded or advanced
since the first unit pulse always appears in the same position on
the CRT if it is used to initiate the sweep of the cathode ray
tube. However, if the large peak in the third pulse coincides in
time with the larger peak of the third pulse in the display (a) for
registered units, it indicates that the first and third units are
in time but the No. 2 unit is out while if the large peak appears
in time ahead or after the peak for the third pulse in the display
for registered units, it indicates that the No. 1 unit is advanced
or retarded. The face of the cathode ray tube may be marked to
indicate the center lines for the pulses of a display showing
registered units to facilitate analysis of the pulses. It should be
further noted that the distortion of the pulses after the fourth
pulse clearly gives an indication as to whether the No. 1 unit or
the No. 2 unit is out of time. If the No. 1 unit is out of time,
the distortion is lost for the last three pulses while if the No. 2
unit is out of time, the distortion is lost for only the last two
pulses. Similarly for other patterns, the pulses after the middle
pulse for the pattern will indicate the nature of the out of time
relationship.
From the foregoing, it will be clear to those skilled in the art
that the magnitude of the pulses and their distortion as well as
the time shift of the leading and trailing edges of the pulses from
the in-register display indicates the timing of the units with
respect to each other and the units which are not on time. It will
also be clear that there will be typical display patterns for a
combination of units out of time and one such display pattern is
shown in the (j) display in FIG. 5. In this display, it is assumed
that the third unit is early and the fourth unit is late.
Accordingly, by analyzing the characteristics of the pulses
particularly the manner of distortion, including the pulse at which
distortion is lost and the time that a pulse begins or ends
relative to its maximum, the registry of the units can be
determined. During operation, when an operator determines that a
unit is out of registry, he operates conventional means to advance
or retard the unit or units to bring the images in registry to each
other.
While preferably the pulse output signals from the sensing devices
are of approximately equal magnitude, it will be understood that
the distortion and change of time of the leading and trailing edges
of the pulses may be utilized to analyze registry even though the
pulse magnitudes are not equal.
Preferably the printing press drives a D.C. tachometer 50 which has
an output applied to the horizontal sweep circuit 44 to vary the
sweep rate with press speed to maintain a constant separation
between pulses on the cathode ray tube for units in registry. If
desired, the sweep circuit could be adjusted manually in accordance
with press speed.
It will be appreciated that electronic circuits for measuring the
pulse height and time are well known and that the pulse height and
time can be analyzed automatically with conventional circuitry to
automatically effect control of the registration of the units.
In the described embodiment, the first register mark initiated the
sweep of the cathode ray tube. It will be understood that the sweep
of the cathode ray tube could be initiated by a fiducial mark on
the press and that all the units, including the first unit, could
be registered with respect to that fiducial mark and the cathode
ray tube could be graduated so that the pulses occur at a
predetermined point on the face of the tube if the units are in
registry. This, however, requires the registering of the first unit
to the fiducial mark.
* * * * *