HDNS-2200 View Datasheet(PDF) - Agilent Technologies, Inc
Part Name
Description
MFG CO.
'HDNS-2200' PDF : 36 Pages View PDF
SQUAL
Access: Read
Address: 0x05
Reset Value: 0x00
Bit
7
6
5
4
3
2
1
0
Field
SQ7
SQ6
SQ5
SQ4
SQ3
SQ2
SQ1
SQ0
Data Type: Eight bit number.
USAGE: SQUAL (Surface QUALity) is a measure of the number of features visible by the sensor in the current frame. The maximum value is 255. Since
small changes in the current frame can result in changes in SQUAL, variations in SQUAL when looking at a surface are expected. The graph
below shows 250 sequentially acquired SQUAL values, while a sensor was moved slowly over white paper. SQUAL is nearly equal to zero, if
there is no surface below the sensor.
SQUAL Values (White Paper)
256
192
128
64
0
0
25
50
75
100
125
150
175
200
225
250
The focus point is important and
could affect the SQUAL value.
Figure 37 shows another setup
with various Z-height. This graph
clearly shows that the SQUAL
count is dependent on focus
distance. The data is obtained by
getting multiple readings over
different heights.
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
-1.0 -0.8 -0.5 -0.3
X + 3σ
X
X – 3σ
0 0.25 0.5 0.75 1.0
DELTA FROM NOMINAL FOCUS (mm)
Figure 37. Typical SQUAL vs. Height, Z.
(white paper)
25
Share Link: 
