Instruction manual

Page 37
Operation
TM-1405GE Hardware
8 Operation
This chapter contains information about performing operational procedures. It contains the following
sections:
• “Progressive Scanning” on page 37
• “Bayer Color Filter (Color Versions)” on page 38
• “Electronic Shutter” on page 41
• “External Sync” on page 42
• “Asynchronous Reset” on page 42
• “Programmable Look-Up Table (LUT) and Knee Control” on page 45
• “Camera Timing Charts” on page 46
• “Video Output” on page 48
• “External HD Locking and External VD Reset” on page 49
• “Asynchronous Reset” on page 49
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-1405GE 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 1040
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-1405GE outputs the progressive scanned image with an electronic shutter in two different
formats.
• Progressive scanning digital - 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.
• Analog output - The analog output is the same as 75 ohms, 714mV format available from BNC
and
12-pin connector.