| 摘要 |
The exemplary bar code reader has an auto-focusing component positioned between a photo-detector array and an object having target indicia. The auto-focusing component has a lens system for focusing the target indicia at an imaging plane that generally co-incides with a plane of the photo-detector array. An electromagnetic coil actuator is coupled to an adjustable aperture such that activation of the coil actuator moves the adjustable aperture into and out of the imaging field of view to adjust a focusing on the target indicia. The autofocus component is fixed when the moveable aperture is within the field of view for focusing on objects close to the reader and when the aperture is removed, the autofocus is effective in imaging objects at a greater distance from the reader. |
