The present technology relates to optical imaging systems, and more specifically, to a standoff accessory for optical imaging systems.
One of the most common imaging systems is the handheld scanner typically used for reading fonts or other symbols or marks on packages or articles, for example. It is important for imaging systems to achieve a quality scan so the image can be electronically searched, stored more compactly, displayed on-line, and used in a variety of machine related processes, including machine translation, text-to-speech and text mining applications.
With a handheld scanner, it can be necessary to position the scanner where the mark is at the right distance and the right angle in front of the scanner, all while providing adequate illumination, in order to achieve a successful scan. This is because in most imaging systems, the size of the image of a mark depends on the distance between the vision sensor and the object containing the mark. Therefore, in applications requiring gauging a size, it can be necessary to have the object at a known distance.
When illumination has been integrated into the imaging system, and more particularly the handheld scanner, the light distribution on the object usually varies with the distance between the object and the vision sensor in the handheld scanner. Proper light distribution is especially important in applications such as reading dot-peen 2D codes with low-angle illumination or verification of direct part marking (DPM) codes, for example.
Especially in handheld scanner applications, it can be difficult to keep the handheld scanner at a proper focal distance where the depth of field is very small, such as when a mark is very small or includes low contrast. As with any imaging device, providing quality results for each image scan can be difficult taking into consideration the numerous variables that affect the quality of an image scan.
What is needed are systems and methods that can improve the quality of results for each image scan by influencing the variables that affect the quality of an image scan.