Datasheet
MLX90640 32x24 IR array
Datasheet
Page 24 of 60
REVISION 11 – 3 AUGUST 2018
Highlighted in yellow parameters are extracted here after.
As a default the device is factory calibrated in Chess pattern mode thus the best performance will be when a Chess
pattern is used. However some customers may choose to use the device in interleaved mode which will degrade the
device performance. In this case a correction can be applied to restore to some extend the performance. Once the IR
data is compensated the calculation for To is done using default flow. The goal of this correction is to equalize the
offset of the pixels due to the different pattern reading modes. We can achieve this by using several correction
coefficients stored into the device EEPROM extracted and decoded as follows:
xy
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If xy
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xy
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xy
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xy
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xy
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q
xy
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Š
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If xy
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xy
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xy
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y
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xy
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‰N
If xy
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xy
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xy
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xy
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xy
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KK
(
The above calculated parameters have to be applied as a correction for the offset of each individual pixel. We do need
additional patterns in order to make these calculations and the formula to calculate those patterns are as shown below
depending on the pixels number:
xy
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11.1.4.
11.1.4.11.1.4.
11.1.4. Restoring the Sensitivity
Restoring the Sensitivity Restoring the Sensitivity
Restoring the Sensitivity
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Where (calculating for pixel (12,16)) :
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