In our previous discussion, we explored how you might not have to choose between a charge-coupled device (CCD) and complementary metal-oxide semiconductor (CMOS) image sensor. However, as of 2015, there are still situations where such a choice is necessary.

The Rise of CMOS in Industrial Imaging

Over the years, CMOS technology has seen significant advancements and widespread adoption across machine vision and global security applications. This trend shows no signs of slowing down.

Current State of CMOS Image Sensors

In just two years since our last examination, there have been major shifts:

  • CCD Dominance (Historically):
    For many years, CCD sensors offered superior performance: a perfect global shutter, minimal dark current, better quantum efficiency (QE) in the near-infrared (NIR), and excellent modulation transfer function (MTF). These factors made them the go-to choice for high-quality imaging.

  • CMOS Improvements:
    In recent years, fueled by consumer market investments, CMOS sensors have seen dramatic enhancements—particularly in QE and read noise. Newer CMOS designs incorporate correlated double sampling (CDS) to achieve better image quality and global shutter performance.

Why CCD Still Matters

CCD technology remains mature and effective, though it’s approaching its technological limits:

  • Read noise has reached nearly optimal levels (~9 electrons).
  • While QE improvements in the NIR are being pursued, dark current management still favors CCD due to its predictable high-temperature behavior. Its perfect global shutter is unmatched for applications like traffic monitoring or liquid level measurement.

CMOS Taking Over

CMOS cameras now dominate traditional machine vision tasks such as inspection and positioning. They’ve also emerged in new areas—like biometrics—thanks to innovations from companies such as CMOSIS.

When to Choose CCD

CCD isn’t obsolete. For applications requiring:

  • A perfect global shutter under constant illumination.
  • Stable performance at extreme temperatures. Applications like traffic monitoring or chemical reaction analysis still benefit from CCD’s strengths.

Summary

While CMOS continues its ascent, CCD remains relevant for niche scenarios where its unique advantages shine.

  • CCD vs. CMOS: Entering the Slope of Enlightenment
  • Increased CCD Use in Machine Vision (for specific conditions)
  • Traffic Applications and CCD/CMOS Selection

Last Updated: 2025-09-04 19:50:45