OCR vision sensor watches out for label(s)
Waldkirch, November 2006 – The new CVS4 is a very rapid, compact and reasonably priced plug & play image processing sensor which is particularly suitable for every type of label inspection. The camera, optics, illumination and evaluation are accommodated in a single housing. Depending on the task, the reading results can be transmitted both as a switching signal and as a data set. Further highlights include the trigger input for automatic increase of, for example, serial batch numbers, and the internal clock that constantly updates both the time and the date.
At the heart of the CVS4 are the integrated high-speed signal processors and the 2-D CMOS image capture unit with 320 x 320 active pixels. This technology makes the device particularly rapid: as the CMOS chip can be contacted by the electronics like a digital storage switching circuit, the CVS4 also has very short cycle times of just a few ms. Further highlights of the series include longer working distances of up to 150 mm, a large field of view, several storable detection programs, and the integrated monitor for menu guidance and status indication.
From simple inspection to demanding reading
Numbers or letters on objects, e.g. packaging, can be detected and compared with the previously taught-in reference label chain thanks to the optical character recognition (OCR) software integrated in the CVS4. The sensor transmits a switching signal that depends on the result of this comparison (“correct” or “incorrect”). Whereby up to 30 incorrect images can be stored or logged in the device. The CVS4 is not, however, only suitable for checking correctness, but also for reading numbers and letters. 60 characters on up to six lines and in several formats, e.g. two dates and two times, can be reliably identified. A pre-defined library of characters is used for detection, and this can be expanded with additional characters via the serial interface.
The CVS4 shows initiative
A total of 16 different reference codes can be stored in the sensor. A variety of optical versions permit character recognition within varying operating distances. Moreover, the CVS4 is always up-to-date: the sensor can, for example, automatically raise a serial batch number via its trigger input. The same applies for the internal clock: it ensures that at midnight the date changes to that of the next day.