Analog Line Scan Cameras
Input Signals (contd.)
Table 2. Camera Description
and a half clock cycles prior to the end
of read out. Because there are extra
stages in the CCD sensors readout regis-
ter, a minimum number of MCLK
cycles (the number of elements on the
CCD sensor plus 41) must exist
Parameter
Physical
Variable
Optical Lens
Sensor Alignment
Dimensions
Description
No lens adaptor - optical
Within 0.005” of of mounting hole
2” x 3.077” x 0.75”
Connector
Type
Amp C-216297
26-pin High Density Male
Maximum 10 meters
between successive LT commands.
Cable Length
The maximum line-scan period is 20
milliseconds. Integration times longer
than 20 ms can introduce higher levels
of dark current, which reduces the
dynamic range of the sensor. Longer
integration times are possible, however,
if the camera is cooled, which reduces
dark current. Specific application char-
acteristics, such as light level and rate
of object motion, will determine the
optimum setting. Timing details are
shown in Figure 3.
Power Requirements Operating Voltages
Connection
+12 VDC, +5 VDC, -12 VDC
Through 26-pin connector
Output
Data Rate
Type
1 - 5 MHz
Analog Differential Video
Through 26-pin connector
Connection
Control Signals
User Supplied
Master Clock (MCLK)
Line Transfer (LT)
User Communications RS-422 Control Signals
Camera Supplied
Camera Clock (CCLK)
Line Enable (LEN)
Camera Line Transfer (CLT)
Through 26-pin connector
Connection
Sensor
Type
Window
PerkinElmer RL1024PAG
Glass
Output Signals
The LC1917-series camera provides
three output synchronization signals:
Camera Clock (CCLK), Line Enable
(LEN), and Camera Line Transfer (CLT).
Operational
Gain Adjustment
Dark Offset Adjustment 5-Turn Potentiometer
5-Turn Potentiometer
The Camera Clock (CCLK) operates at
the MCLK frequency and is synchro-
nized to the analog video. The output
of the CCLK signal can be used to cap-
ture analog video data by a frame
grabber or digitizer.
Figure 3. Camera Timing Diagram
CCLK
The Line Enable (LEN) signal brackets
the valid analog video. The signal
becomes high two CCLK periods before
the first valid pixel and goes low two
CCLK periods before the last valid
pixel. The video output is a contiguous
pixel data stream with a dynamic
range (defined as peak video divided
by rms pixel noise) of greater than 2500:1.
The minimum period between LT must be 41 + 1024 CLKS or 1065 clocks
LT
LT minimum = 1.5 CLKS
CLT equals
6 CLKS
CLT
The Camera Line Transfer (CLT) output
signal is an internally generated sync
signal. Its falling edge indicates the
start of a line readout sequence. This
signal may be used for controlling
strobes, shutters or other accessories
of the users system.
CLT to LEN 11 CLKS
LEN
LEN leads and trails video by 2 CLKS
Video Signals
The LC1917 camera features an
adjustable DC offset. This offset is con-
trolled by a potentiometer, located
underneath the set screw on the body
side of the camera adjacent to active
Video
1024 CLKS
www.perkinelmer.com/opto
DSP-205.01A - 4/2001W Page 3
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