BM-141GE / BB-141GE
23
How to calculate total line number and frame rate on variable partial scan mode
Variable partial scan The start line setting
1st line to 1025th line
Read out height
8 lines to 1032 lines
Total lines = OB period in the upper part of the frame (L) + Fast Dump period in the upper
part of the frame (L) + Effective image period (L) + Fast dump period in the
lower part of frame(L)
Where, OB period in the upper part of the frame 3L
Fast dump period for the upper part
5
7
.
o
StartlineN
Roundup
+2
Fast dump period for the lower part
5
.
1039
EndLineNo
Roundup
+2
Frame rate (fps) = 1000000 / (Horizontal pixel No x Pixel clock x Total lines)
Horizontal Pixel number 1830
Pixel clock
17.24138 ns
Calculation example
Read out: 1/2 partial at the center (520L), Stat line (261), End line (780)
OB period in the upper part of the frame 3L
Fast dump period for the upper part = (261+7) ÷ 5 +2 = 55.6
→
56
Fast dump period for the lower part = (1039-780) ÷ 5 +2
=
53.8
→
54
Total lines = 3
+
56
+
520
+
54
=
633
Frame rate = 1000000 ÷ (1830 ×17.24138 × 633) = 50.06 fps
7.4. Digital video output
7.4.1 Digital Video Output (Bit Allocation)
Although the BM-141GE and BB-141GE are digital cameras, the image is generated by an
analog component, the CCD sensor.
The table and diagram below show the relationship between the analog CCD output level and
the digital output.
CCD out
Analog Signal *
Digital Out
8 bit
10 bit
12 bit
Black
Setup 3.6%, 25mV
8 LSB
32 LSB
128 LSB
200mV
700mV
222 LSB
890 LSB
3560 LSB
230mV
800mV
255 LSB
1023 LSB
4095 LSB