U.S. patent application number 11/122721 was filed with the patent office on 2005-11-24 for auto-tracking spectrophotometer.
Invention is credited to Baker, Douglas V., Berg, Bernard J., Kalinka, Gary T., Robinson, Frederick G., Walker, Timothy L..
Application Number | 20050259251 11/122721 |
Document ID | / |
Family ID | 34968785 |
Filed Date | 2005-11-24 |
United States Patent
Application |
20050259251 |
Kind Code |
A1 |
Kalinka, Gary T. ; et
al. |
November 24, 2005 |
Auto-tracking spectrophotometer
Abstract
An auto-tracking spectrophotometer has a moveable look-ahead
sensor for scanning at least a portion of a color matrix. The
look-ahead sensor finds a portion of the color matrix for
measurement by an optical system. The optical system for measuring
the color matrix is then guided using the information provided by
the look-ahead sensor.
Inventors: |
Kalinka, Gary T.; (Wyoming,
MI) ; Walker, Timothy L.; (West Olive, MI) ;
Robinson, Frederick G.; (Hamilton, MI) ; Berg,
Bernard J.; (Wayland, MI) ; Baker, Douglas V.;
(Middleville, MI) |
Correspondence
Address: |
WARNER NORCROSS & JUDD LLP
900 FIFTH THIRD CENTER
111 LYON STREET, N.W.
GRAND RAPIDS
MI
49503-2487
US
|
Family ID: |
34968785 |
Appl. No.: |
11/122721 |
Filed: |
May 5, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60568356 |
May 5, 2004 |
|
|
|
Current U.S.
Class: |
356/319 |
Current CPC
Class: |
G01J 3/0264 20130101;
G01J 3/0267 20130101; G01J 3/0291 20130101; G01J 3/02 20130101;
G01J 3/0289 20130101; G01J 3/50 20130101; G01N 21/251 20130101 |
Class at
Publication: |
356/319 |
International
Class: |
G01J 003/06 |
Claims
The embodiments of the invention in which an exclusive property or
privilege is claimed are defined as follows:
1. An apparatus for color measurement of an image comprising: a
first moveable scanning device for producing a first scan of at
least a portion of the image; a second moveable scanning device for
color measurement of the image; and a positioning system for
positioning the second moveable scanning device based upon the
first scan.
2. The apparatus of claim 1 where the first moveable scanning
device is moveable relative to the image.
3. The apparatus of claim 2 where the first moveable scanning
device and the second moveable scanning device are located within
an enclosure and the enclosure is moveable relative to the
image.
4. The apparatus of claim 3 further comprising a first linear
movement means for moving the second moveable scanning device in at
least a first direction.
5. The apparatus of claim 4 where the first linear movement means
is located within an enclosure.
6. The apparatus of claim 5 where the positioning system is a
tracking board coupled to the second moveable scanning device and a
first stepper motor.
7. The apparatus of claim 6 further comprising a second linear
movement means for moving the enclosure in at least a second
direction.
8. The apparatus of claim 7 further comprising a sample holding
surface for holding the image.
9. The apparatus of claim 8 further comprising a holder for
maintaining the image on the sample holding surface.
10. The apparatus of claim 9 where the holder comprises a vacuum
pump.
11. The apparatus of claim 6 where the apparatus includes a
station, the station being in a fixed position relative to the
enclosure.
12. The apparatus of claim 11 where the station includes at least
the second linear movement means.
13. The apparatus of claim 12 where the station includes a vacuum
control coupled to a vacuum pump.
14. The apparatus of claim 3 further comprising a communication
link between the enclosure and a second system for processing or
storage.
15. The apparatus of claim 14 where the second system for
processing or storage is located in the station.
16. The apparatus of claim 14 where the second system for
processing or storage is coupled to the second moveable scanning
device.
17. The apparatus of claim 15 further comprising: a rotating means
for rotating the second moveable scanning device about at least a
first axis.
18. The apparatus of claim 17 further comprising: an angle detector
system for detecting at least one angle of the image.
19. The apparatus of claim 18 where the rotating means is actuated
in response to the angle detector system.
20. The apparatus of claim 19 where the angle detector system
comprises the first moveable scanning device.
21. The apparatus of claim 20 where the first moveable scanning
device and the second moveable scanning device are located within a
head and the head is moveable relative to the image.
22. The apparatus of claim 21 further comprising a first linear
movement means for moving the second scanning device in at least a
first direction.
23. The apparatus of claim 22 further comprising a tracking board
coupled to the first moveable scanning device and the first linear
movement means.
24. The apparatus of claim 23 where the tracking board is coupled
to the second scanning device.
25. The apparatus of claim 24 further comprising a second linear
movement means for moving the head in at least a second direction,
the second direction being generally orthogonal to the first
direction.
26. The apparatus of claim 25 where the tracking board is coupled
to the second linear movement means.
27. The apparatus of claim 26 further comprising a sample holding
surface for holding the image.
28. The apparatus of claim 27 further comprising a holder for
maintaining the image on the sample holding surface.
29. The apparatus of claim 28 where the apparatus includes a
station, the station being in a fixed position relative to the
head.
30. The apparatus of claim 29 where the station includes the second
linear movement means.
31. The apparatus of claim 30 where the station includes a vacuum
control coupled to the vacuum pump.
32. The apparatus of claim 31 further comprising a communication
link between the head and a second system for processing or
storage.
33. The apparatus of claim 32 further comprising a data network
connection.
34. A head for moveably scanning an image comprising: a first
scanning device for producing a first scan of a portion of the
image; and a second scanning device for producing a second scan of
the image, where the first scanning device is positioned so as to
precede the second scanning device when the head is moveably
scanning an image.
35. The head of claim 34 where the second scanning device is
moveable relative to the first scanning device.
36. The head of claim 34 further comprising at least one linear
movement means for moving the second scanning device in at least a
first direction.
37. The head of claim 34 further comprising: a rotational means for
rotating the second scanning device about at least a first
axis.
38. The head of claim 37 further comprising: a linear movement
means for moving the second scanning device in a first linear
direction.
39. A method for moving a first scanning device during a scan of an
image comprising: detecting image information during the scan; and
moving the first scanning device relative to the image during the
scan based upon the image information.
40. The method of claim 39 where the image has at least a first
color threshold and a second color threshold, and further comprises
determining a location based upon the first color threshold and the
second color threshold.
41. The method of claim 40 further comprising detecting the image
information by moving a second scanning device relative to the
image.
42. The method of claim 40 further comprising: moving the first
scanning device and the second scanning device in at least a first
direction; and moving the first scanning device relative to the
second scanning device in at least a second direction.
43. The method of claim 42 further comprising: analyzing an output
from at least the second device to determine the image information;
and moving the first scanning device in at least the second
direction to based upon the image information.
44. The method of claim 43 where the image information indicates an
image feature.
45. The method of claim 44 where a center line is determined from
the image feature.
46. The method of claim 40 where the image is on a color strip
further comprising detecting an edge of a color strip.
47. The method of claim 46 further comprising: an angle of the
color strip relative to the first direction.
48. The method of claim 47 further comprising: compensating for the
angle.
49. The method of claim 48 where the step of compensating for the
angle comprises rotating the first scanning device.
50. The method of claim 45 further comprising: where the image is
on a substrate, detecting a substrate edge.
51. The method of claim 50 further comprising: determining a
thickness of the substrate.
52. The method of claim 51 further comprising: calculating a scan
speed.
53. The method of claim 52 further comprising: obtaining color
information about the image from at least the second scanning
device.
54. A method of scanning at least one color patch with a scanner,
the scanner having at least first scanning device moveable in at
least first direction and a second direction, comprising:
determining a location of the at least one color patch; determining
at least a first angular orientation of the at least one color
patch; and compensating for at least first angular orientation.
55. The method of claim 54 further comprising rotating the first
scanning device.
56. A system for measuring a color target, the color target
contained within an image at a location, comprising: a first memory
for storing a map of the image, the map indicating the location of
the color target; at least a first scanning device moveable in at
least a first direction; and a mechanism for moving the first
scanning device to the location.
57. The system of claim 56 further comprising: an alignment system
for aligning the first scanning device with the color target.
58. The system of claim 57 where the first scanning device and the
alignment system are mounted on a head.
59. The system of claim 58 where the first scanning device is
moveable relative to the alignment system.
60. The system of claim 59 where the alignment system has a wider
field of view than the first scanning device.
61. The system of claim 60 further comprising an interpreter for
comparing information from the alignment system with the map.
62. The system of claim 61 further comprising: a second memory, the
second memory containing a plurality of image maps; and a selector
for selecting one of the plurality of image maps to be placed into
the first memory.
63. The system of claim 62 where the selector is comprised of a
means for interpreting encoded data.
64. The system of claim 63 where the mechanism is a user assisted
device.
65. A method of measuring a color target, the color target found at
a location on an image, comprising: determining the location from a
map stored in a memory; moving at least a first scanning device to
the location; and scanning the color target.
66. The method of claim 65 further comprising precisely locating
the color target.
67. The method of claim 66 further comprising: providing at least a
first scanning device for precisely locating the color target.
68. The method of claim 67 further comprising: moving at least a
second scanning device to the location.
69. A method for measuring a color target with at least a first
scanning device, the color target found at a location on an image,
comprising: determining the location from a map stored in a first
memory; moving a second scanning device to the location; precisely
determining a position of the color target; and scanning the color
target with the first scanning device.
70. The method of claim 69 further comprising: selecting the map
from a plurality of image maps.
71. The method of claim 70 further comprising: scanning a portion
of the image; selecting from the portion a first image map from the
plurality of image maps corresponding to the image; and loading the
corresponding first image map into the first memory as the map.
72. The method of claim 71 where the step of scanning a portion of
the image comprises: reading encoded data.
Description
BACKGROUND OF THE INVENTION
[0001] This patent application claims the benefit of to Provisional
Patent Application No. 60/568,356, filed May 5, 2004, and entitled
AUTO-TRACKING SPECTROPHOTOMETER.
[0002] An auto-tracking spectrophotometer (ATS) measures and
analyzes spectral data. Since spectral data provides the most
complete and accurate description of color, an ATS is the ideal
control system for both process and special color print jobs.
[0003] An ATS has a table for holding a color composition, a head
for performing a scan of the color matrix, and a station, located
at one end of the table. In order to use the ATS, an operator
places a color graphic composition have a color target on the ATS
platen. A vacuum pump is then energized so as to hold the
composition onto the table.
[0004] The ATS head then scans the entire color target first to
locate the beginning and ending points of the color target. After
the beginning and ending of the color target are located, the ATS
assumes that the color bar proceeds linearly between the beginning
and ending of the color bar. Based upon this assumption, the ATS
positions its data acquisition optics over what should be the color
target, and then scans the area. After the head returns to the
station, the measurement is then transmitted to a computer.
Software on the computer displays an overview of the color data.
The computer or an operator may then adjust the controls of a press
used to more accurately reproduce the graphic composition.
[0005] ATS have proven invaluable in modem printing plants.
However, they have limitations. Care must be taken by the operator
of the ATS to align composition in the ATS. If not, the color
target may be slightly curved when placed on the table. Further, if
the composition is contained on a folded sheet of paper, additional
care must be taken to compensate for the fold in the color target.
If the color target is not properly aligned, the color target may
not be accurately read.
[0006] Additionally, at least two scans are required by the ATS.
The multiple scans may cause significant time delays. Finally, even
with the multiple scans, the alignment of the color target may not
be acceptable, resulting in faulty color information.
[0007] Further, the scan information is not transmitted to the
computer until the head is returned to the station. This delays the
time before the data is analyzed, resulting in delays in completing
the print job.
[0008] An improved ATS which overcomes these problems is thus
highly desirable.
SUMMARY OF THE INVENTION
[0009] An improved ATS is provided with a look-ahead visual sensor.
The look-ahead sensor retrieves an image and a tracking controller
finds the location of a color matrix. The color matrix could be a
color target, a color profile target, a color bar code, a color
picture, or any other amalgamation of colors. A controller moves
the data acquisition optics in response to output from the
look-ahead sensor. In this way, the data acquisition optics
maintains a proper orientation with respect to the color
matrix.
[0010] Additionally, a stepper motor for controlling movement of
the ATS head in an X-direction is controlled directly by the head.
Thus, all components for accurately tracking the color bar are
located in the head.
[0011] In order to improve the efficiency of the ATS, the vacuum
pump is provided with a solenoid controlling the coupling of vacuum
holes located in the paper table with the vacuum pump.
[0012] During the scan, information from the data acquisition
optics is continually transmitted to a remote computer by way of a
communication channel between the head and the computer. Thus, the
computer can immediately begin analyzing the data.
[0013] The communication channel is established by way of a
communication interface, which could be an Ethernet connection. The
head communicates to the by way of an Ethernet connection.
[0014] These and other objects, advantages and features of the
invention will be more readily understood and appreciated by
reference to the detailed description of the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 shows several auto-tracking spectrophotometers
connected to computers by way of a network.
[0016] FIG. 2 shows an auto-tracking spectrophotometer.
[0017] FIG. 3 shows the contents of the head of an auto-tracking
spectrophotometer.
[0018] FIG. 4 shows a block diagram of an auto-tracking
spectrophotometer.
[0019] FIG. 5 is a flowchart showing the operation of an
auto-tracking spectrophotometer.
[0020] FIG. 6 is a flow chart indicating shows how the color
information is collected from color matrix by an auto-tracking
spectrophotometer.
DETAILED DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1 shows a printing plant with several ATS. Computers
10, 12 are connected by way of network 14 to a plurality of ATS
systems 16, 18, 20. ATS systems 16, 18, 20 may communicate with
computers 10, 12 by way of a standard protocol such as TCP/IP, or,
if necessary, by a proprietary communication protocol.
[0022] FIG. 2 shows an ATS 20. ATS 20 consists of table 22, head
24, and station 26. Table 22 includes platen 23 and track 25. Table
22 is sample holding surface. In some applications, table 22 could
be a curved surface.
[0023] Vacuum pump 28 is attached to station 26 by way of tube 30
and vacuum inlet 33. Table 22 has vacuum holes 32. When a graphic
composition is placed on table 22, vacuum pump 28 is energized,
thus creating a means to hold the graphic composition to table 22.
The graphic composition is generally on a substrate, such as
paper.
[0024] Station 26 includes communication interface 34 and RS232
interface 36. ATS 20 can be connected to a network by way of
network interface 34. Network interface 34 could be a standard
RJ-45 connection. ATS 20 could be directly connected to a computer
by way of RS232 interface 36 or network interface 34.
[0025] After a graphic composition is placed on platen 23, head 24
moves across the color chart and reads the color chart on the
graphic composition, and transmits the information to a
computer.
[0026] FIG. 3 shows the contents of head 24. Head 24 serves as an
enclosure for various components. Various circuit boards required
to operate head 24 are not shown. Arrow 41 shows the movement of
the head 24 in the direction of the scan, which is referred to
hereinafter as the X-direction. Head 24 includes a NCIS
(non-contact image system) 40, data acquisition optics 42, and
Y-step motor 44. Y-step motor 44 is connected to data acquisition
optics 42 by way of y-drive mechanism 46. Information regarding the
location of the color matrix is acquired by non-contact image
system 40 and is used to control Y-step motor 44 in order to
accurately position data acquisition optics 42 over the color
matrix. NCIS 40 is spaced approximately 21/2 inches from the data
acquisition optics 42. Y-step motor 44 and Y-drive mechanism 46
form a positioning system.
[0027] FIG. 4 shows a block diagram of ATS 20. Station 26 includes
x-home sensor 52, vacuum control 54, track store 56, communication
interface 58, and x-stepper motor 60. X-home sensor 52 detects the
x-position of head 24 whenever head 24 is docked with station 26.
Vacuum control 54 is connected to vacuum pump 28. Vacuum control 54
controls vacuum inlet solenoid 62. When vacuum control 54 energizes
vacuum inlet solenoid 62, a vacuum is applied to table 22. Track
store 56 contains information regarding the track such as the
length of the track.
[0028] Communication interface 58 provides bidrectional
communication between ATS 20 and a computer or computers by way of
a network. Communication interface 58 includes an Ethernet
connection as well as an RS232 interface. X-stepper motor 60
controls the x-position of head 24.
[0029] Station 26 is connection to head 24 by way of interface 63
which could be an RS232 serial interface or an LVDS (Low Voltage
Digital Signaling) interface. Head 24 includes tracking board 64,
y-stepper motor 66, NCIS module 68, DAS (Digital Acquisition
System) board 70 and lamp board 72. Tracking board 64 is connected
to NCIS module 68 and DAS board 70. Station 26 could be a system
for processing or storage of information from head 24.
Alternatively, systems other than head station 26 could provided
for the processing and storage of information.
[0030] Tracking board 64 receives information from NCIS module 68
to control the x-position of head 24 and the y-position of DAS
board 70 and lamp board 72. Tracking board 64 is connected to
X-stepper motor 60. Tracking board 64 provides commands to
X-stepper motor 60 to move head 24. Tracking board 64 is also
connected to NCIS module 68. Tracking board 64 uses the information
received from NCIS module 68 to correctly position DAS board 70 and
lamp board 72 in the y-direction.
[0031] DAS board 70 is connected to tracking board 64. DAS board 70
provides the color information to tracking board 64. Tracking board
64 then relays the information by way of interface 63 to station 26
and ultimately to a network or a computer. Lamp board 72 is a known
device for acquiring color information from a target.
[0032] FIG. 5 is a flowchart showing the operation of ATS 20. A
color calibration application starts on a computer connected to ATS
20. Step 100. When ATS 20 receives a signal from the computer that
an application has started, ATS 20 energizes vacuum pump 28. Step
102. In this way, a vacuum will be immediately accessible at table
22. After a job is selected on the computer (Step 104), the job
information is sent to station 26. Step 106. The job information
could include data regarding the size of the color matrix such as
height, width of individual color patches within the color matrix,
number of colors.
[0033] From the job information, station 26 calculates the optimal
speed for movement of head 24 in the x-direction. Step 108. The PC
then sends a command to station 26 to start the color measurement.
Step 110. Station 26 then sends a command to DAS board 70 to begin
measurement. Step 112. DAS board 70 then initializes itself by
performing such tasks as spinning the color wheels, energizing the
lamp, and energizing the sensors. Step 114. DAS board 70 then
begins sending information to the computer. Step 116. When
communication between the DAS board 70 and the computer is
confirmed, station 26 sends a command to tracking board 64 to begin
scanning in the x-direction. Step 118. Tracking board 64 then sends
a command to x-stepper motor 60 to move head 24 in the x-direction.
Step 120.
[0034] Tracking board 64, by way of NCIS module 68, then begins to
look for the paper edge. Step 122. When a paper edge is detected by
tracking board 64, tracking board 64 sends a message to the
computer that a paper edge has been found and also sends to the
computer the X/Y-location of the paper edges. Step 124. After the
edge is found, tracking board 64 by way of NCIS module 68 begins to
search for the color matrix. Step 126. When the color matrix is
found (step 128) the tracking board 64 stores the X/Y-location of
the start of the color matrix in memory. Step 130.
[0035] Tracking board 64 controls x-stepper motor 60 and maintains
a counter indicative of the x-position of head 24. DAS board 70
then collects color information from the color matrix. Step
132.
[0036] FIG. 6 is a flow chart indicating shows how the color
information is collected from color matrix 132. Tracking board 64
sends a command to X-stepper motor 60 to move head 24 in the
x-direction. Step 200. Tracking board 64 stores the x-location of
the head 24 in memory 65. Tracking board 64 by way of the NCIS
module 68 detects the Y-location of the color matrix. Step 202. It
stores the Y-location in memory 65. Step 204. Because NCIS module
68 is located approximately 2 1/2 inches in advance of lamp board
72, tracking board 64 uses previously stored data regarding
location of the color matrix to control the y-position of lamp
board 72 with stepper motor 66.
[0037] Tracking board 64 retrieves the y-position of the color
matrix for the current x-position of the lamp board 72 from memory
65. Step 206. Tracking board 64 then moves lamp board 72 to the
current y-position. Step 208. Color information is then read from
the color matrix. Step 210. The color information is then sent to
the computer. Step 212.
[0038] At the same time NCIS module 68, is searching for the edge
of the paper. Step 214. If the edge is detected, then the reading
of the color matrix ends. Otherwise, the process repeats.
[0039] Returning to FIG. 5, after all color information has been
collected, 24 head is returned to its original position. Step 134.
When head 24 is docked with station 26, ATS 20 sends a message to
the computer that head 24 is docked. Step 136. The solenoid is
de-energized. Step 138. The color reading is then completed. Step
140.
[0040] The above description is of the preferred embodiment.
Various alterations and changes can be made without departing from
the spirit and broader aspects of the invention as defined in the
appended claims, which are to be interpreted in accordance with the
principles of patent law including the doctrine of equivalents. Any
references to claim elements in the singular, for example, using
the articles "a," "an," "the," or "said," is not to be construed as
limiting the element to the singular.
* * * * *