High resolution lenses for machine vision — standard and custom lens design
Machine Vision Utilizes CCD and CMOS Technologies
High Resolution Lenses for machine vision, instrumentation, inspection and vibration-sensitive applications. Standard and custom hi-res lens assemblies.
In the machine-visioning world, the evolution of and the uses for CCD and CMOS technologies is a debate that continues. Specialists in the machine-visioning realm remain divided on which type of image sensor is best suited for the myriad applications that are available.
The advantages of a CCD sensor are:
- The ability to rise above read noise performance
- Light sensitivity
- Quality of the image
The advantages of CMOS sensors are:
- Low manufacturing cost
- Operates at high speeds
- Provides for on-chip system integration
Traditionally, machine-visioning technologies embraced CCDs as they were considered the superior quality device as compared to CMOS sensors. The CCD sensor offers a higher resolution and operates at a higher dynamic range. In machine-visioning, capturing lower image quality can lead to a reduced accuracy in measurement and repeatability of processes. CCDs also incorporate an electronic shutter and this eliminates the need for the moving parts of a mechanical shutter system. CCDs, however, operate at lower/slower frame rates, use more power, and cost more to integrate than CMOS sensors.
In recent years, CMOS sensors have shown improvements in overall quality including its ability to operate at a higher speed, using less power and the ability to more easily integrate with machine-visioning technologies. It’s believed that it won’t be long before CMOS sensors overtake CCDs in the technology realm and in user acceptance. While CCDs remain the superior sensor in capturing images with lower noise levels, CMOS sensors are closing the gap.
Both sensors are manufactured much the same way as memory chips or microprocessors; the main differentiator is that CCD sensors are manufactured under a proprietary process while CMOS sensors are a more innovative cycle for manufactures. CCDs continue to maintain an advantage over CMOS sensors although the advantages and benefits are shrinking; both sensors provide viable options in the marketplace of machine-visioning.