ICX274AL Datasheet, PDF (16/71 Pages) Sony Corporation – Diagonal 8.923mm (Type 1/1.8) Progressive Scan CCD Image Sensor with Square Pixel for B/W Video Cameras

Center scan and AF modes
ICX274AL
Undesired portions (Swept by vertical register high-speed transfer)
Picture center cut-out portion
Description of Center Scan and AF Mode Operation
The center scan and AF modes realize high frame rates by sweeping the top and bottom of the picture with
high-speed transfer and cutting out the center of the picture.
The various readout modes during center scan and AF operation are described below.
• AF modes
AF mode (1), (2): The output method is the same as readout in 2/8-line readout mode.
• Center scan modes
Center scan mode (1): The output method is the same as 2/4-line readout mode.
Center scan mode (2): The output method consists of 2-line addition readout whereby the signals for only
two out of four lines (3rd and 4th lines, 7th and 8th lines, and so on) are read out,
the vertical register is shifted by 2 bits, and then the signals of the remaining two
out of the four lines (1st and 2nd lines, 5th and 6th lines, and so on) are read out
and added within the vertical register.
Center scan mode (3): The output method is the same as progressive scan mode.
The readout method, frame rate, number of output lines and other information for each readout mode are
shown in the table below.
Mode
Progressive scan mode
2/8-line readout mode
2/4-line readout mode
2-line addition mode
Center scan mode (1)
Center scan mode (2)
Center scan mode (3)
AF mode (1)
AF mode (2)
Readout method
Addition
method
Number of output
Frame rate (frame/s) effective pixel data
lines
28.6MHz 36MHz 28.6MHz 36MHz
Progressive scan
None
9.99 14.985 1220
1220
2/8-line readout
None
29.97 29.97
305
305
2/4-line readout
None
19.98 19.98
610
610
2/4-line readout
Vertical 2-line 19.98 19.98
1220
1220
2/4-line readout
None
29.97 29.97
434
568
2-line addition readout Vertical 2-line 29.97 29.97
434
568
Progressive scan
None
29.97 29.97
444
580
2/8-line readout
None
59.94 59.94
170
235
2/8-line readout
None
119.88 119.88
43
75
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