JAI PULNiX TM-4100GE, Руководство по эксплуатации

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Page 40
Operation
TM-4100GE Hardware
8 Operation
8.1 Progressive Scanning
Standard TV-system scanning is 525 lines interlace scanning as specified in the RS-170 protocol. Every
other horizontal line (odd lines and even lines) is scanned at a 60Hz rate per field, and the scanning is
completed with two fields (one frame) at 30Hz rate. Because of the interlace scanning, the vertical
resolution of CCD cameras is limited at 350 TV lines, regardless of the horizontal resolution. When
electronic shutter is applied, the CCD can hold only one field of charge at each exposure. This means
that the vertical resolution of the electronic shutter camera is only 244 TV lines. The situation is the
same for an HDTV-format camera, since it has interlaced scanning and the vertical resolution of the
shuttered image is 500 lines.
The TM-4100GE uses a state-of-the-art progressive scanning interline transfer CCD which scans all
lines sequentially from top to bottom at one frame rate. Like a non-interlace computer screen, it
generates a stable, crisp image without alternating lines and provides full vertical TV resolution of 2048
lines (a normal computer monitor has a maximum display of 1600 lines).
The interline transfer architecture is also important to generate simultaneous shuttering. This is different
from full frame transfer architecture, which requires a mechanical shutter or strobe light in order to
freeze the object motion.
The TM-4100GE outputs the progressive scanned image with an electronic shutter in two different
formats. See Table 8 on page 45 for more information.
1.
Progressive scanning digital output
The CCD signal goes through A/D converters 10-bit in, 10-bit/8-bit out. The digital
output is available using the Gigabit Ethernet connector.
2.
Full Progressive Scan
Normal scanning mode for the TM-4100GE is 2k x 2k pixels. The standard speed with
dual-channel output is 15 frame/sec at the pixel clock of 40 MHz. The progressive scan
reads every line from top to bottom and all lines are exposed with a single electronic
shutter.
FIGURE 28.
Full Progressive Scan Mode (A)
line 1
line 2
n
n+1