| 摘要 |
Apparatus for reading a barcode comprises a lens and a plurality of photosensors 908 attached to a carrier 1130 and a housing 902. The housing has an external surface 1125 and an internal surface 1119. The external surface has a first reference portion 1102 and the internal surface has a second reference portion 1104, which is aligned with the first reference portion. The carrier 1130 is attached to the second reference portion 1104 such that upon the first reference portion 1102 being positioned at a predetermined distance away from the image, light is substantially focused onto the photosensors. The apparatus may also include a plurality of optical emitters and a circuit configured to supply substantially the same electrical current to the each of the emitters. The apparatus may be arranged such that, as the housing thermally expands, the lens and photosensors move in opposite directions to maintain the focusing of light. |
