Instruction manual
Guppy Technical ManualV7.4.0
78
Description of the data path
Readout schemes: Guppy interlaced models
(F-038, F-038 NIR, F-044, F-044 NIR, F-025,
F-029)
The Guppy F-038/038 NIR/044/044 NIR/025/029 cameras use so-called inter-
line scan interlaced CCDs.
Interlaced means: one complete image is scanned or reconstructed by a tempo-
ral succession of odd lines and interleaved even lines.
NIR means: near infrared. These sensors are equipped with the SONY EXview HAD
technology improving sensitivity (also in the near infrared light region: 700 nm
to 1000 nm).
Advantages of interlaced CCDs compared to progressive CCDs:
• More simple shift register (2-phase shift register per pixel element com-
pared to progressive CCDs with 3-phase shift register per pixel element)
and higher fill factor of pixels
• Vertical binning (aka field integration) increases sensitivity by a factor of
two
• Very sensitive EX-View HAD sensors available (PAL/NTSC resolution)
In the following chapters the 3 different readout modes of the Guppy interlaced
models are explained:
• Format_7 Mode_0: interlaced, field integration (vertical binning)
• Format_7 Mode_1: interlaced, frame integration
• Format_7 Mode_2: non-interlaced, field integration (horizontal + vertical
binning), so-called progressive readout mode
4-phase vertical shift register
The interline interlaced CCDs use 4-phase vertical shift register and two gates for
two vertical pixels. The gates are used to control field or frame integration:
• Field integration: the two gates are activated at the same time
–see Figure 43: Format_7 Mode_0: 4-phase vertical shift register pre-
charging (interlaced, field) on page 79 and
– Figure 49: Format_7 Mode_2: 4-phase vertical shift register precharg-
ing (non-interlaced, field) on page 83
• Frame integration: the two gates are activated every other field
–see Figure 46: Format_7 Mode_1: 4-phase vertical shift register pre-
charging (interlaced, frame) on page 81
• Pre-charging of the phases defines interlaced or non-interlaced.
Note
For demosaicing process outside of the camera, see Chapter
BAYER pattern (raw data output) on page 134.