ADNS-2051 Avago Technologies US Inc., ADNS-2051 Datasheet - Page 37

• Manufacturer Part Number: ADNS-2051
• Description: Optical Mouse Sensor,DIP
• Manufacturer: Avago Technologies US Inc.

Specifications of ADNS-2051

• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: Q2072083C

37
Shutter_Lower
Access: Read
Shutter_Upper
Access: Read
Data Type: Sixteen bit word.
USAGE: Units are clock cycles; default value is 64. Read Shutter_Upper first, then
Shutter_Lower. They should be read consecutively. The shutter is adjusted to keep
the average and maximum pixel values within normal operating ranges. The shutter
value can be adjusted to a new value on every frame. When the shutter adjusts, it
changes by ±1/16 of the current value. Shown below is a graph of 250 sequentially
acquired shutter values, while the sensor was moved slowly over white paper.
The focus point is important and could affect the shutter
value. The graph below shows another setup with various
z-height. This graph clearly shows that the shutter value
is dependent on focus distance.
Figure 41. Typical shutter vs. Z (white paper)
Note: This graph shows average readings over different
heights.
800
600
400
200
3.5
3.0
2.5
2.0
1.5
1.0
0.5
Field
Field
0
0
DISTANCE FROM NOMINAL FOCUS (mm)
TYPICAL SHUTTER vs. Z (WHITE PAPER)
-1.0 -0.8
0
Bit
Bit
-0.5
S
S
7
7
15
7
-0.3
25
X+ 3σ
X
X – 3σ
0
S
S
6
6
14
6
0.25
0.5
50
S
S
5
5
13
0.75
5
1.0
S
75
S
4
4
12
Address: 0x0e
Reset Value: 0x64
Reset Value: 0x00
Address: 0x0f
4
S
S
3
3
11
3
SHUTTER VALUES (WHITE PAPER)
100
S
S
2
2
10
2
125
S
S
1
1
1
9
150
S
S
0
0
0
8
175
200
225
250