TCD1709D Datasheet, PDF (6/13 Pages) Toshiba Semiconductor – TOSHIBA CCD Linear Image Sensor CCD (Charge Coupled Device)

TCD1709D
Note 10: Random noise is defined as the standard deviation (sigma) of the output level difference between two
adjacent effective pixels under no illumination (i.e. dark condition) calculated by the following procedure.
Video output
Video output
Output waveform
200 ns
200 ns
(effective pixels
under dark condition)
s
pixel n
pixel (n + 1)
1) Two adjacent pixels (pixel n and n + 1) in one reading are fixed as measurement points.
2) Each of the output levels at video output periods averaged over 200 nanosecond period to get Vn and
Vn + 1.
3) Vn + 1 is subtracted from Vn to get ∆V.
∆V= Vn − Vn + 1
4) The standard deviation of ∆V is calculated after procedure 2) and 3) are repeated 30 times (30 readings).
DV
=
1
30
30
Ã¥ DVi
i=1
  s =
1
30
30
Ã¥
i=1
DVi
-
DV
2
5) Procedure 2), 3) and 4) are repeated 10 times to get 10 sigma values.
s
=
1
10
10
Ã¥ sj
j=1
6) I value calculated using the above procedure is observed 2 times larger than that measured relative to
the ground level. So we specify the random noise as follows.
Random noise = ¹ I
2
6
2002-11-14