Digital Signal Processing Reference
In-Depth Information
15
R1
R2
R3
R4
1
0
1
0
1
0
0
0
0.02
0.04
0.06
0.08
0.1
0.12
0.14
0.16
0.18
0.2
15
C1
C2
C3
C4
1
0
1
0
1
0
0
0
0.02
0.04
0.06
0.08
0.1
0.12
0.14
0.16
0.18
0.2
Time [s]
Fig. 5.13
Measured output of the row and column selector circuit. Although the measured sig-
nals are the correct signals, their high level does not properly stick to the digital level 15V. This
measurement is performed at a clock frequency of 100Hz
Fig. 5.14
Chip photograph of the 2
D
touch sensor on flexible foil. This circuit ismade in technology
provided by Polymer Vision
only differentiate between the rows and the dimension of the sensor is reduced from
2 to 1. This is schematically shown in Fig.
5.15
where the parasitic path through the
finger is present, even when switch
C
i
is off, hence every pixel located on row
R
j
is sensed as active. Solutions for this problem do exist, e.g. the use of synchronous
