| 摘要 |
A hand-held imager which is capable of reading both linear and two dimensional symbologies, which can perform focusing and illuminating steps quickly and accurately so as to eliminate variation in the position of the imager relative to the code becoming a negative factor. The imager includes an imaging system having a focusing system, an illumination system, and a two-dimensional photodetector which forms an image of the coded symbology. After achieving targeting of the coded symbology, the scanning system adjusts the focus and illumination between multiple different focuses, and utilizes a portion of the two-dimensional photodetector to determine the optimum focus and illumination. Upon the determination of optimum focus and illumination, and an image is created using the entire two-dimensional photodetector. Predefined multiple sets of illuminating parameters intensity, exposure and gain can be used to determine the proper focus and illumination. |
