| 摘要 |
<p>An electronic shelf label (ESL) is provided. The ESL includes a printed circuit board, PCB, a photo sensor sensitive to infra-red, IR, radiation and arranged at the PCB, an outer cover in which a window is arranged to admit light and IR radiation towards the photo sensor. The ESL further includes a filter arranged in front of the photo sensor and separate from the window, the filter being adapted to admit IR radiation and filter out light within the visible wavelength range. Further, the ESL includes index matching material transparent to IR radiation and coated on the PCB such that it covers the photo sensor and provides direct or indirect physical contact between the photo sensor and the filter. Such enables use of a photo sensor which is not pre-coated with index matching material, which reduces manufacturing costs.</p> |
