Optical symbologies imager
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, in which can operate in environment where the imager is anywhere from 1.5 inches to 16 inches from the code. 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 between multiple different focuses, and utilizes a portion of the two-dimensional photodetector to determine the optimum focus. Upon the determination of optimum focus, the focusing system is returned to the focusing configuration established in the initial focusing step, and an image is created using the entire two-dimensional photodetector. Optimum illumination is determined using the same two-dimensional photodetector.
1. An optical symbology imager, comprising:
a multiple line charge coupled device (CCD) having an active area;
a focusing apparatus comprising a focusing disk with multiple optical positions to provide different focal lengths, said disk being rotatable so that each of said multiple optical positions can move into an optical path of said imager;
a microprocessor for controlling said focusing apparatus and operation of said CCD, so that said CCD performs image capture producing image data for each of said multiple optical positions;
said microprocessor controlling said CCD to shift out said image data substantially serially;
said microprocessor evaluating transitions between light and dark data in a central set of multiple lines to produce a representative value for each of said multiple optical positions, wherein a largest representative value corresponds to one of said optical positions producing optimum focus; and
wherein said CCD disposes of a first set of multiple lines without reading and digitizing said first set of multiple lines at a first rate of speed during focusing, and then samples a second subsequent set of multiple lines from said central set of scan lines at a second rate of speed less than said first rate of speed during focusing.
2. An optical symbology imager as recited in claim 1 , wherein said representative value is produced by totaling a first seven to ten values from multiple values produced for each of said multiple focusing positions.
3. An optical symbology imager as recited in claim 1 , wherein said optical symbology imager is hand-held.
4. An optical symbology imager as recited in claim 1 , wherein said first set of multiple lines is 246 lines.
5. An optical symbology imager as recited in claim 1 , wherein said second set of multiple lines is substantially ten lines.
6. An optical symbology imager in accordance with claim 1 wherein said multiple line CCD has a resolution of 659 by 494.
7. An optical symbology imager in accordance with claim 1 , wherein said microprocessor only utilizes said central set of multiple lines to produce the optimum focus.
8. An optical symbology imager in accordance with claim 1 , wherein said multiple optical positions are at least two.
9. An optical symbology imager in accordance with claim 1 , wherein said multiple optical positions are eight.
10. An optical symbology imager in accordance with claim 1 , wherein said multiple optical positions are twelve.