Schäfter+Kirchhoff SK6288VKOC-4L User manual

© 2018-04 E [email protected] www.SuKHamburg.com
Instruction Manual SK6288VKOC-4L shared_Titel_ML.indd
SK6288VKOC-4L
Color Line Scan Camera
3x 2096 pixels 14 x 14 µm², line frequency up to 9.26 kHz
Instruction Manual
SK6288VKOC-4L
3
2
Sample Configuration
1CCD line scan camera
SK6288VKOC-4L
mounted with
2Mounting bracket SK5105-L
3Clamping claws SK5101
4Focus adapter FA22R-45 (two-piece),
facilitates adjustment of any rotation angle
5Enlarging lens Apo-Rodagon N 4.0/80
5
4
1
400 500 700 800600
Wavelength (nm)
0
Responsitivity
(V/mJ/cm2)
100
0.0
1.0
400 500 600
Wavelength (nm)
Relative sensitvity
color

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How to Use this Instruction Manual
Electricity Warning
Assembly and initial operation of the line scan camera must be carried out under dry
conditions.
Do not operate the camera if you notice any condensation or moisture in order to avoid danger
of a short circuit or static discharge!
Risk of High Power Lighting
According to the application, laser or high power LED light sources might be used. These can
affect your eyesight temporarily or even cause permanent damage to the eyes or skin.
Do not look directly into the light beam!w
Mechanics Warning
Ensure that the motion device and the scan way is free to move and that no obstacles are in
the way.
Do not place any part of the body in the way of moving parts!
Line scan cameras are mostly used in combination with a motion device such as a translation
stage, a conveyer or a rotational drive, as well as with high intensity light sources.
For assembly close down these devices whenever possible. Beyond that, please consider the
following warnings:
Safety Warnings
Please read the following sections of this Instruction Manual before unpacking, assembly or use
of the Line Camera System:
The safety warnings on this page
Introduction to the system, page 4
Assembly and initial setup, page 6
Keep this Instruction Manual in a safe place for future reference.
!

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Contents
How to Use this Instruction Manual 2
Safety Warnings 2
Contents 3
1 Introducing the SK6288VKOC-4L Line Scan Camera �������������������������������������������� 4
1.1 Intended Purpose and Overview 4
1.2 System Setup at a Glance 5
1.3 Computer System Requirements 6
1.4 SK6288VKOC-4L Line Scan Camera - Specifications 6
2 Installation and Setup ������������������������������������������������������������������������������� 7
2.1 Mechanical Installation: Mounting Options and Dimensions 7
2.2 Electrical Installation: Connections and I/O Signals 8
2.3 GigE Connections and Software Installation 9
GigE Network Integration for Standard GigE Network Adapters
2.4 SkLineScan Software Installation (Optional) 11
SkLineScan Installation
SkLineScan Start-up
Camera Setup
Initial Function Test
3 Camera Control and Performing a Scan  �������������������������������������������������������� 12
3.1 Software: SkLineScan 12
Function Overview: SkLineScan Toolbar
Basic Visualization of the Sensor Output
3.2 Adjustments for Optimum Scan Results 14
Lens Focussing
Sensor Alignment
Gain/Offset Adjustment
White Balance and Shading Correction
Integration Time
Synchronization of the Imaging Procedure and the Object Scan Velocity
Synchronization Modes
RGB Sensors: 2D Imaging and Pixel Allocation
3.3 GigE Vision Device Feature List (Gen<i>Cam compliant) 24
4 Advanced SkLineScan Software Functions ����������������������������������������������������� 26
4.1 Camera Control by Commands 26
Set Commands
Request Commands
4.2 Advanced Synchronization Control 28
Advanced Trigger Functions and Sync Control Register Settings
Example Timing Diagrams of Advanced Synchronization Control
5 Sensor Information �������������������������������������������������������������������������������� 30
Glossary 34
CE-Conformity 37
Warranty 37
Accessories 38

Introducing the SK6288VKOC-4L Line Scan Camera
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The SK line scan camera series is designed for a wide
range of vision and inspection applications in both
industrial and scientific environments.
The SK6288VKOC-4L GigE VisionTM line scan camera
uses the Gigabit Ethernet communication protocol
and is 100% compliant with the GigE VisionTM
specifications and the Gen<I>CamTM standard.
GigE Vision allows for fast image transfer using low
cost standard cables up to distances of 100m. With
GigE Vision, hardware and software from different
vendors can interoperate seamlessly via the GigE
connections. The camera is connected to a computer
either via the GigE socket directly or through a Gigabit
Ethernet switch.
When taking the camera into operation the first
time the Schäfter+Kirchhoff SkLineScan®program
is recommended. Once the camera driver and the
SkLineScan®program have been loaded from the
SkLineScan CD or zip-file then the camera can be
parameterized. The parameters, such as integration
time, synchronization mode or shading correction,
are permanently stored in the camera even after a
power-down or disconnection from the PC.
The oscilloscope display in the SkLineScan®program
can be used to adjust the focus and aperture settings,
for evaluating field-flattening of the lens and for
orientation of the illumination and the sensor, see
14.6 GigE Connections and SkLineScan Software
Installation (p. 69).
The Schäfter + Kirchhoff GigE Vision line scan
cameras implement a superset of the Gen<I>Cam™
specification which defines the device capabilities.
The settings made in the SkLineScan®program are
automatically provided to the device feature liste of any
Gen<I>Cam compliant software.
The Gen<I>CamTM standard provides a generic
programming interface for all kinds of cameras and, no
matter what features they implement, the application
programming interface (API) always remains the same.
The Gen<I>CamTM standard consists of multiple
modules relevant to the main tasks to be solved:
GenApi: for configuring the camera
Standard Feature Naming Convention (SFNC):
recommended names and types for common features
GenTL: transport layer interface, for grabbing images
For more information on the GigE VisionTM
specification, see:
https://www.visiononline.org/vision-standards-details.
cfm?type=5
or the Gen<I>CamTM standard:
http://www.emva.org/standards-technology/genicam/
1 Introducing the SK6288VKOC-4L Line Scan Camera
1.1 Intended Purpose and Overview
CCD line scan camera
2Power supply
3Illumination
Software Gen<i>Cam
-compliant, eBus driver
GigE switch
14
5
PC or
Notebook
with GigE
GigE interface for transmission
of video and control data over
distances up to 100 m
421
3
Application:
Parallel
acquisition
using a
GigE switch
4
2
1
5

Introducing the SK6288VKOC-4L Line Scan Camera
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1.2 System Setup at a Glance
red: SK6288VKOC-4L scope of delivery
blue: accessories for minimum system configuration
black: optional accessories
For accessory order details see Accessories (p. 36).
Motion unit
with encoder
Synchronization cable
Power supply cable
Gigabit Ethernet cable
Computer
Power supply
unit
Schäfter+Kirchho
SkLineScan®adjustment
and control software
3rd party software
that supports the
GEN<i>CAMTM standard
Line scan camera
Clamping claw
Mounting bracket
Optics (e. g. lens,
focus adapter, tube
extension ring)

Sensor category CCD Color Sensor
Sensor type KLI2113
Pixel number 3x 2096
Pixel size (width x height) 14 x 14 µm2
Pixel spacing 14 µm
Line spacing, line sequence 112 µm, blue (B) - green (G) - red (R)
Active sensor length 29.3 mm
Anti-blooming -
Integration control x
Shading correction x
Line synchronization modes Line Sync, Line Start, Exposure Start, Exposure Active
Frame synchronization x
Pixel frequency 60 / 30 MHz
Maximum line frequency 9.26 kHz
Integration time 0.01 ... 20 ms
Dynamic range 1:2500 (rms)
Spectral range 400 ... 700 nm
Video signal color 3*8 Bit digital
Interface GigE Vision
Voltage 24 V DC
Power consumption 4.9 W @ 60 MHz
Casing 65 mm x 65 mm x 72.4 mm (Case type BG3)
Objective mount M45x0.75
Flange focal length 19.5 mm
Weight 0.3 kg
Operating temperature +5 ... +45°C
Introduction
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1.3 Computer System Requirements
1.4 SK6288VKOC-4L Line Scan Camera - Specifications
Introduction
• Intel Pentium Dual Core or AMD equivalent
• RAM min. 4 GB, depending on size of acquired
images
• High-performance video card, PCIe bus
• Operating Systems:
Windows 7 / 8.1 / 10 (64 or 32-bit) or
Linux kernel 3.13 or higher
• CD/DVD drive for software installation.
Network Adapter:
• Any Gigabit Ethernet network adapter as a card
or on the motherboard is suitable. For the best
performance, a network interface card (NIC) with
Intel PRO/1000 chip is recommended.
• PCIe adapters outperform PCI adapters.
• Network adapters that support Jumbo Frames
outperform adapters with fixed packet-size frames.

Installation and Setup
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2 Installation and Setup
2.1 Mechanical Installation: Mounting Options and Dimensions
Casing type BG3
Mounting Options
• The best fixing point of the camera is the collar for
the mounting bracket SK5105-L (available as an
accessory).
• Four threaded holes M3x 6.5 mm provide further
options for customized brackets.
• The length and weight of the optics might be beyond
the capability of the standard mounting bracket
SK5105-L. For this purpose, a second mounting
bracket type SK5105-2L to hold the tube extension
ring(s) is more appropriate.
Optics Handling
• If the camera and the optics are ordered as a kit,
the components are pre-assembled and shipped
as one unit. Keep the protective cap on the lens
until the mechanical installation is finished.
• If you must expose the sensor or lens surface,
ensure the environment is as dust-free as possible.
• Gently blow off loose particles using clean
compressed air.
• The sensor and lens surfaces can be cleaned with
a soft tissue moistened with water or a water-based
glass cleaner.
Mounting bracket SK5105-L
Mounting system SK5105-2L
for cameras with a tube
extension > 52 mm
Clamping set SK5101
Set of 4 pcs. clamping claws
incl. screws
66
10 10
36
M3 Ø3.3
6
50.3
41.7
Ø 47.5
50
20
16.5
3.5
6.5
Ø4.3
15 M4
1/4’’ 20G
40
63
70
6
36
Ø 47.5
70
3.5 31.5
25
10
3.5
70
63
40
1/4’’20G
M4
Ø4.3
Hex socket head screw
DIN 912–M3x12
Clamping claw
65
72.4
2.5 6
425.1
FFL
Ø65
Ø47.5
50/M3/4x90°
12.7
Pixel 1
M3 (4x)
depth 6.5 mm
65
M45x0.75
58
41.7
BG3 Lens mount: M45x0.75
Seat for bracket: Ø47.5 mm
Flange focal length: FFL = 19.5 mm
CCD-Sensor

3
1
2
1Power +24 V Hirose series 10A, male 4-pin
Total power: 4.9 W @ 60 MHz
Pin Signal Pin Signal
1n.c. 3n.c.
2GND 4min. +18 V
max. +36 V
2
1
3
4
Power Cable SK9014.xF
Use this cable to feed external supply voltage into socket 1.
Connector:
Hirose plug HR10A, female 4pin (camera side),
open cable end (other side)
Length 1.5 m (standard), 3 m, or 5 m
Installation and Setup
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2.2 Electrical Installation: Connections and I/O Signals
External Synchronization Cable SK9024.x
Use this cable to feed external synchronization
signals into socket 2.
Connectors:
Hirose plug HR10A, female 12pin (camera side)
Phoenix 6 pin connector incl. terminal block (for
synchronization signals)
Length 3 m or 5 m. Other lengths on request.
Network Cable CAT6.x
For connecting socket 3with the PC Ethernet
interface. Both ends with RJ45 connectors.
• For the SK6288VKOC-4L line scan camera-data transfer and camera control is provded by the Gigabit
Ethernet interface 3. Use a CAT6 twisted-pair cable to connect the camera to a PC; the maximum cable
length is 100 m.
• The operating power must be supplied by an external source using socket 1
• If you want to operate the camera in FREE RUN trigger mode, the connections are complete with the CAT6
Ethernet cable and the connection to an external power supply.
• For any kind of synchronized operation, the external trigger signal(s) must be wired to socket 2as well. A
frame-synchronization signal and two separate line-synchronization signals can be handled. The various
trigger modes are described fully in section Synchronization of the Imaging Procedure and the Object
Scan Velocity (p. 20)
2
1
3
4
5
6
7
8
9
10
1112 2
1
3
4
5
6
Pin Signal *)
1GND
8FrameSync IN
10 LineSync A IN
6LineSync B IN
2I/O Connector Hirose series 10A, male 12-pin
*) Signal Specification
(TTL) Max. input frequency 16.5 MHz
Input voltage,
absolute max. range
min -0.5 V
max 7.0 V
Input voltage max. low 0.99 V
Input voltage min. high 2.31 V
Input current 10 µA
Installation and Setup
3Data
RJ-45 connector for Gigabit Ethernet cable
Status indicators
Network connection speed Network activity
off no connection,
10 Mbyte/s connection, or
100 Mbyte/s connection
on 1 Gbyte/s connection
off no connection
on connected
flash
light
data is being
transmitted or
received
Accessories (see also Accessories (p. 36)):

Installation and Setup
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Installation and Setup
2.3 GigE Connections and Software Installation
GigE Network Integration for Standard GigE Network Adapters
The SK6288VKOC-4L GigE VisionTM line scan camera uses the Gigabit Ethernet communication protocol, which is
100% compliant with the GigE VisionTM specifications and the Gen<I>CamTM standard.
The Gen<I>CamTM standard provides a generic programming interface for all kinds of cameras and, no matter what
features they implement, the application programming interface (API) always remains the same.
For software and Network Interface Controller (NIC) driver installation, the following possibilities apply:
1. The Gen<I>CamTM compliant 3rd party software you want to install includes a particular filter driver for
the NIC.
Install the software package. Commonly this will also cover the driver installation.
2. The 3rd party software does not include a NIC filter driver, and your NIC has an INTEL PRO/100 chip.
Install the Pleora eBUS Optimal Driver.
3. The 3rd party software does not include a NIC filter driver, and your NIC has a different chip.
Keep the manufacturer driver and follow the instructions in the next section.
The Pleora eBUS driver installation tool is available from Schäfter + Kirchhoff either on CD or as download from
http://www.sukhamburg.com/supporte.html
a) Subnet Setting
The GigE Vision camera has an enforced static IP
address. The NIC IP address must be part of the same
subnet otherwise the camera is not accessible.
An example of a persistent IP address that is assigned
to a class B network is:
Persistent IP = 169.254.35.10
Subnet Mask = 255.255.0.0
Default Gateway = 0.0.0.0
This section is relevant for systems with a standard NIC (not INTEL PRO /1000) in combination with the
manufacturer driver (case 3).
B
A

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b) Windows Firewall
a) Switch off the Windows Firewall or
b) Allow an exception:
Start > Control Panel > Open the Windows Firewall
Select the Exceptions tab
Click Add Program
The "Add a Program" dialog appears
Select the camera control program and click "OK"
Click "OK" to close the Windows Firewall dialog
c) Optimizing the Network Adapter Settings
Open the "Advanced" Properties tab Dof the Network
Adapter and enter the following values:
Jumbo Frames 9014 Bytes
Receive Descriptors 2048
Interrupt Moderation Rate extreme
Energy Efficient Ethernet OFF
Network Controller Properties: Note, the terms
can differ depending on the installed Ethernet
card and driver.
D
C
To Set the NIC IP address:
Start > Control Panel > Network Connections.
Right-click Local Area Connection and select Properties.
The Local Area Connection Properties dialog appears.
Select Internet Protocol (TCP/IP) and click Properties. The
Internet Protocol (TCP/IP) Properties dialog appears.
Enable "Use the following IP address" and enter the
following settings:
IP address: 169.254.35.10
Subnet mask: 255.255.0.0
Default gateway: leave blank
Ensure these do not conflict with an existing IP address on
another NIC. For multiple dedicated connections on the
same host PC, increment the third IP address by one for
each NIC (i.e. 36, 37, etc., subnet 255.255.255.0 - class C).
Click OK to close the Internet Protocol (TCP/IP) Properties
dialog.
Click Close to close the Local Area
Connection Properties dialog.
Your NIC is now configured for a
dedicated connection.
A
B
C
LAN Connection 4
Speed: 1.0 GBit/s
Status: Connected

Installation and Setup
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Initial Function Test
• Quit the SkLineScan startup dialog
box.
• Select "OK" in the SkLineScan
start-up dialog.
The Signal Window plotting the current
brightness versus the pixel number
indicates the correct installation.
Camera Setup
Use the Setup dialog for
• activating/deactivating a connected
GigE camera (activated device is
ticked)
• changing the IP address
• changing the pixel frequency
• setting the bit depth of the video
signal to 8 or 12-bit.
The MAC addresses are displayed for identification of each camera with the defined CamID (0, 1, …). This is
useful when several cameras with the same name are connected.
SkLineScan Setup dialog
SkLineScan Start-up
• Start SkLineScan. A start-up dialog box pops up
and displays the connected cameras that have
been automatically detected. Desktop Icon
2.4 SkLineScan Software Installation (Optional)
SkLineScan Installation
Prior to the installation, power on the PC (not the camera) and unpack the downloaded zip-file to a temporary
folder. Alternatively, if your installation medium is a CD, insert the disk into the drive.
The autostart function may launch the setup program automatically from CD. Otherwise, look for the installation
file:
SkLineScan_GEV.msi
Then start the applicable installation file manually. This will set up the Schäfter + Kirchhoff SkLineScan camera
control and adjustment tool.
This section is a quick reference for installing the SkLineScan adjustment and configuration software.
SkLineScan and the SkLineScan manual is provided for download on the Schäfter + Kirchhoff website under
http://www.sukhamburg.com/supporte.html.

Camera Control and Performing a Scan
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3 Camera Control and Performing a Scan
New line scan. All open "Signal window" windows will be closed. [F2]
"Camera Control" dialog for parameter settings: integration time, line frequency, synchronization mode,
thresholding
Zooming in and out
New line scan. "Area Scan" windows will be closed, "Signal window" windows will remain open. [F2]
Threshold mode in new binary signal window.
"Shading Correction" dialog to adjust the white balance [Alt+ s]
"Gain/Offset Control" dialog, also for commands input [Shif+F4]
New area scan
For an in-depth guide on how to perform imaging and to use the obtained data using the Schäfter + Kirchhoff
software package, see the SkLineScan Software Manual.
The most common functions of the line scan camera can be controlled by menu items and dialog boxes.
Commands controlling comprehensive camera functionality can be entered in the "Camera Gain / Offset
Control" dialog.
Click on the desktop icon to start the SkLineScan
program.
The SkLineScan program recognizes the connected line
scan cameras automatically. The identified cameras
are shown in the start-up dialog A, and the index order
corresponds with the individual MAC addresses of the
cameras.
If the SK6288VKOC-4L camera is identified correctly,
confirm with "OK". The "Signal window" graphicaly
showing the intensity signals of the sensor pixels
(oscilloscope display) will open. It is responsive in
real-time and the zoom function can be used to
highlight an area of interest. The oscilloscope display
is ideally suited for parameterizing the camera, for
evaluating object illumination, for focussing the image
or for aligning the line scan camera correctly.
3.1 Software: SkLineScan
This section is a brief introduction to the SkLineScan adjustment and configuration software. A more detailed
description is provided in the separate SkLineScan manual. The pdf is included in the SkLineScan installation
package or is available for download from the Schäfter + Kirchhoff website under http://www.sukhamburg.com/
support.html.
Function Overview: SkLineScan Toolbar
SkLineScan: Toolbar
SkLineScan: Start-up dialog
A

Camera Control and Performing a Scan
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Basic Visualization of the Sensor Output
• Signal Window / Oscilloscope Display
The signal window plots the digitalized brightness profile as signal intensity (y-axis) versus the sensor length (x-axis)
at a high refresh rate. The scaling of the y-axis depends on the resolution of the A/D converter: The scale range is
from 0 to 255 for 8-bits and from 0 to 4095 for 12-bits. The scaling of the x-axis corresponds with the number of
pixels in the line sensor.
• Zoom Function
For high numbers of sensor pixels, the limited number of display pixels might be out of range, in which case the
zoom function can be used to visualize the brightness profile in detail. Magnification of one or several sections of
the signal allows individual pixels to be resolved for a detailed evaluation of the line scan signal.
• Window Split Function
The signal window can be split horizontally into two sections. Use the split handle Bat the top of the vertical scroll
bar and afterwards arrange the frames using the zoom buttons in the toolbar.
Line scan in Signal
Window: brightness
vs. pixel number
B
Line scan in Signal
Split signal window.
The upper frame
shows a magnified
section of the lower
frame.

Start with the signal window / oscilloscope display. Any changes in the optical system or camera parameters
are displayed in real-time when using an open dialog box.
The oscilloscope display facilitates the effective focussing of the line scan camera system, even for two-dimen-
sional measurement tasks. For determining the correct focus, the edge steepness at dark-bright transitions and
the modulation of the line scan signal are the most important factors.
Adjust the focus using a fully opened aperture to restrict the depth of field and to amplify the effects of focus
adjustments.
The signal amplitude may require trimming when using a fully opened aperture and this can achieved most readily
by shortening the integration time, as described in section Integration Time (p. 19).
Camera Control and Performing a Scan
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• Lens focussing
• Sensor alignment
• Gain/Offset
• Shading correction
• Integration time
• Synchronization of the sensor exposure and
the object surface velocity, trigger mode
options.
Prior to a scan, the following adjustments and parameter settings should be considered for optimum scan
signals:
Out-of-focus:
• Low edge steepness
• Signal peaks are blurred
• High-frequency gray values with low
modulation
Optimum focus:
• Dark-bright transitions with steep edges
• Large modulation in the signal peaks
• High-frequency gray value variations
3.2 Adjustments for Optimum Scan Results
Lens Focussing
Camera Control and Performing a Scan

Gain/Offset Control dialog
The gain/offset dialog contains up to 6 sliders for altering gain and offset. The number of active sliders depends
on the individual number of adjustable gain/offset channels of the camera. When "Coupled Gain Channels" is
ticked, all channels are adjusted synchronously with one slider.
Enter commands for advanced software functions in the 'Camera Control' field (see page 13).
Camera Control and Performing a Scan
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If you are operating with a linear illumination source, check the alignment of the illumination source and the sensor
prior to performing a shading correction, as rotating the line sensor results in asymmetric vignetting.
Sensor and optics rotated in apposition Sensor and optics aligned
Cameras are shipped prealigned with gain/offset factory settings. Open the "Gain/Offset Control" dialog to
re-adjust or customize these settings.
Adjustment principle
1. Offset
To adjust the zero baseline of the video signal, totally
block the incident light and enter "00" (volts) for
channel 1.
For a two- or multi-channel sensor, minimize any diffe-
rences between the channels by adjusting the other
Offset sliders.
A slight signal noise should be visible in the zero
baseline.
2. Gain
Illuminate the sensor with a slight overexposure in order
to identify the maximum clipping. Use the Gain slider
"1" to adjust the maximum output voltage.
For a two- or multi-channel sensor, minimize any diffe-
rences between the channels by adjusting the other
Gain sliders.
For the full 8-bit resolution of the camera, the maximum
output voltage is set to 255 and for 12-bit is set to
4095.
Sensor Alignment
Gain/Offset Adjustment
Offset and gain adjustment for more than one gain/offset channel
2. Adjust channel 1 gain
and minimize difference
between channels
using Gain slider
1. Adjust channel 1 zero
level and minimize diffe-
rence between channels
using Offset slider

Camera Control and Performing a Scan
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Shading Correction compensates for non-uniform illumination and lens vignetting, as well as any differences in
pixel sensitivity. The signal from a white homogeneous background is obtained and used as a reference to correct
each pixel of the sensor with an individual factor. The result is a leveled signal along the full sensor length. A
shading correction with a balanced RGB sensitivity ensures a natural color reading. The reference signal is stored
in the Shading Correction Memory (SCM) of the camera and subsequent scans are normalized using the scale
factors from this white reference.
Step 1: White Balancing
• Use a homogeneous white object, e.g. a white sheet of paper, to acquire the RGB line signals.
Color line signal with separated RGB curves
White Balancing by Gain Adjustment
• Open the "Gain/Offset Control" dialog. Use the gain sliders to adjust all three curves to the same level. Some
camera models provide two gain/offset channels - thus two sliders - per color.
"Gain/Offset Control" Dialog
Camera Control and Performing a Scan
White Balance and Shading Correction

Camera Control and Performing a Scan
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White Balancing by Individual Integration Time Control
In some circumstances, it is not possible to adjust the white
balance using the gain setting because of:
• dynamic limitations from a very intensive or weak illumination,
• undesired changes in noise level.
For such situations, an individual adjustment of integration times for the Red, Green, and Blue channels is
available, for a general description of the integration time adjustment, see section Integration Time (p. 19).
Check that the weakest color signal is higher
than about 70%. If necessary, adjust the
line frequency or the illumination intensity
accordingly.
Tick the box "Decoupling LF" Ain the "Camera
Control" dialog.
Reduce the integration times for the two color
channels with the higher signals in order to align
the Red, Green and Blue channels to the same
level.
The Red channel is adjusted using the slider
"Exposure Time". B
For the Green and Blue channels, enter the
exposure time into the respective boxes. C
Color line signal with the Red signal adjusted to that of the Blue channel; the Green channel is still separate
Color line signal with balanced RGB curves
A
B
C
This approach is only available for
camera models providing Integ-
ration Control function, see camera
specifications page 6.

Camera Control and Performing a Scan
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a) Using a white homogeneous
background
• Open the Shading Correction dialog
(Alt+s).
Use the entries in the left column to obtain
shading correction reference data from a
white homogeneous background.
• Use a homogeneous white object to
acquire the reference data, e.g. a white
sheet of paper.
• Either take a 2-dimensional scan ("Area
Scan Function" [F3] ) or
use a single line signal that was averaged
over a number of single line scans.
• To suppress any influence from the surface
structure, move the imaged object during
the image acquisition.
• Input the scale range:
Minimum in %: intensity values lower than
“Minimum” will not be changed.
A typical appropriate value is 10% of the full
intensity range, i.e. 26 (= 10% · 255) for an 8-bit
intensity scale.
Maximum in %: target value for scaling
A typical appropriate value is 90% of the full
intensity range. The result will be a homogeneous
line at 230 (= 90% 255) for an 8-bit intensity scale.
• Click on button New Reference
• Click on Save SCM to Flash to save the SCM
reference signal in the flash memory of the camera
b) Analytic compensation of
natural lens vignetting
• Open the Shading Correction dialog (Alt+s).
Use the entries in the middle column to calculate
the reference data based on the imaging setup.
• Enter the parameters focal length (FL), sensor
length (SL) and field of view (FOV) according to your
setup.
The implemented algorithm will compensate the
natural lens vignetting.
• Click on Save SCM to Flash to save the SCM
reference signal in the flash memory of the camera
Step 2: Obtaining the Shading Correction Data
The shading correction refrence data that is stored in the shading correction memory (SCM) can be obtained in
two ways:
Shading Correction dialog
Parameters for correction of natural lens vignetting:
FL = Focal Length of the lens in mm
SL = Sensor Length in mm
FOV = Field Of View in mm
Power-down and Power-up Behaviour
The shading correction memory (SCM) buffer is a volatile
memory. Its content is lost on power-off.
Once the reference signal is copied from the SCM to the
camera flash memory, it will persist even after a power-
down. On a re-start, this data will be restored automatically
from the flash memory back into the SCM.
The shading correction status on shutting down - active or
not active - will be retained and automatically restored on
power-up.
Color line signal
with separated
RGB curves after
Gain Adjustment
and Shading
Correction
Save SCM to Flash Save the SCM reference
signal in the flash memory of
the camera
ON Activate Shading Correction
with the reference signal that
is stored in the SCM.
OFF Switch off Shading Correction.
This does not affect the
content of the camera SCM
buffer or the camera flash
memory.
Save SCM to File The SCM reference signal will
be stored in a file.
Load File to SCM A stored reference signal will
be loaded into the SCM of the
camera. If the load process
completes then the Shading
Correction is active.

Camera Control and Performing a Scan
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Integration Time
The range of intensity distribution of the line scan signal
is affected by the illumination intensity, the aperture
setting and the camera integration time. Conversely,
the aperture setting influences the depth of field as well
as the overall quality of the image and the perceived
illumination intensity.
The line scan signal is optimum when the signal from
the brightest region of the object corresponds to 95%
of the maximum gain. Full use of the digitalization
depth (256 at 8-bit, 4096 at 12-bit) provides an
optimum signal sensitivity and avoids over-exposure
(and blooming).
A camera signal exhibiting insufficient gain: the
integration time is too short as only about 50%
of the B/W gray scale is used.
Optimized gain of the camera signal after
increasing the integration time, by a factor of 4,
to 95% of the available scale.
Shading Correction Memories and API Functions
As an alternative to the user dialog, a new shading correction reference signal can also be created by using
application programming interface (API) functions. The relationshhip between the storage locations and the related
API functions are shown in the diagram below. The API functions are included in the SK91USB3-WIN software
package. See the SK91USB3-WIN manual for details.
Structure of the shading correction memories and the related API functions for memory handling
Camera Control and Performing a Scan
• Open the "Camera Control" dialog.
Menu Edit -> Operation Parameters or [F4]
• The integration time can be set by two vertical
sliders or two input fields in the section "Integration
Time" of this dialog. The left slider is for coarser the
right for finer adjustments.
• The current line frequency is displayed in the Line
Frequency status field.
• The adjustment of the integration time in the range
of Integration Control (shutter) that is shorter than
the minimum exposure period does not change the
line frequency. This will be held at the maximum.
• The 'Default' button sets the integration time to the
minimum exposure period that is determined from
the maximum line frequency.
• 'Reset' restores the start values.
• 'Cancel' closes the dialog without changes.
• 'OK' stores the integration time values and closes
the dialog.
• For synchronization settings, see section
Synchronization of the Imaging Procedure and
the Object Scan Velocity, p. 20.
SkLineScan Camera Control dialog

FOV
S
V0
Pixel #1
Pixel #1
WP/ ß
CCD Sensor
Scan Object
Camera Control and Performing a Scan
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The optimum object scan velocity is calculated from:
WP·fL
VO=
ß
If the velocity of the object carrier is not adjustable then
the line frequency of the camera must be adjusted to
provide an image with the correct aspect ratio, where:
VO·ß
fL=
WP
VO= object scan velocity
WP= pixel width
fL= line frequency
S= sensor length
FOV = field of view
ß= magnification
= S / FOV
A two-dimensional image is generated by moving either the object or the camera. The direction of the translation
movement must be orthogonal to the sensor axis of the CCD line scan camera.
To obtain a proportional image with the correct aspect ratio, a line-synchronous transport with the laterally
correct pixel assignment is required. The line frequency and the constant object velocity have to be coordinated.
In cases of a variable object velocity or particularly high accuracy requirements then an external synchronization
is necessary. The various synchronization modes are described below.
Example 1:
Calculating the object scan velocity for a given field of view and line frequency:
Pixel width = 14 µm
Line frequency = 9.26 kHz
S= 29.3 mm
FOV = 50 mm
14 µm · 9.26 kHz
VO=
(29.3 mm / 50 mm)
= 221 mm/s
Example 2:
Calculating the line frequency for a given field of view and object scan velocity:
Pixel width = 14 µm
Object scan velocity = 200 mm/s
S= 29.3 mm
FOV = 50 mm
200 mm/s · (29.3 mm / 50 mm)
fL=
14 µm
= 8.4 kHz
Synchronization of the Imaging Procedure and the Object Scan Velocity
Camera Control and Performing a Scan