MLX90255-BA
Linear Optical Array
6. Cosine Correction
When using a single LED light source, which is placed above the middle of the die, the light intensity that
falls onto the outer pixels is lower than the light intensity that falls onto the middle pixels (due to the
distance die-LED, the shape of the LED light emission and the sensitivity of pixels vs. angle of incident
light). To compensate for these effects, each pixel in the array has a slightly different gain correction with
respect to the centre of the array. For a light source to photodiode array distance of 15mm the relative
pixels sensitivities are shown in the table below.
Relative
Pixel
Sensitivity
Relative
Pixel
Sensitivity
Relative
Pixel
Sensitivity
Relative
Pixel
Sensitivity
Pixel
number
Pixel
number
Pixel
number
Pixel
number
1
2
3
4
5
6
7
8
9
132 1.1703
131 1.1649
18 115 1.0912
19 114 1.0874
20 113 1.0836
21 112 1.0799
22 111 1.0764
23 110 1.0729
24 109 1.0695
25 108 1.0661
26 107 1.0629
27 106 1.0598
28 105 1.0567
29 104 1.0537
30 103 1.0508
31 102 1.0480
32 101 1.0453
33 100 1.0426
35 98 1.0376
36 97 1.0352
37 96 1.0328
38 95 1.0306
39 94 1.0284
40 93 1.0263
41 92 1.0243
42 91 1.0224
43 90 1.0206
44 89 1.0188
45 88 1.0171
46 87 1.0155
47 86 1.0140
48 85 1.0126
49 84 1.0112
50 83 1.0099
51 82 1.0087
52 81 1.0076
53 80 1.0066
54 79 1.0056
55 78 1.0047
56 77 1.0039
57 76 1.0031
58 75 1.0025
59 74 1.0019
60 73 1.0014
61 72 1.0010
62 71 1.0006
63 70 1.0003
64 69 1.0002
65 68 1.0000
66 67 1.0000
130 1.1596
129 1.1544
128 1.1493
127 1.1442
126 1.1393
125 1.1345
124 1.1298
10 123 1.1251
11 122 1.1206
12 121 1.1161
13 120 1.1117
14 119 1.1074
15 118 1.1032
16 117 1.0991
17 116 1.0951
34 99
1.0400
390109025502
Rev. 008
Page 6 of 12
Nov/05
MELEXIS [ Melexis Microelectronic Systems ]
