Delay Equalization in Event-Based Vision Sensors

Strategic Insights -

The patent describes a system for equalizing delays in event-based vision sensors, which are crucial for various machine vision tasks such as monitoring, tracking, and position and motion estimation. Conventional cameras and their associated frame-based, spatially resolved optical sensors have drawbacks, including a significant amount of redundant and unnecessary data, limited dynamic range, poor low-light performance, and motion blur. In contrast, Dynamic Vision Sensors (DVS) can achieve high temporal resolution, low latency, low power consumption, and high dynamic range with little motion blur.

The invention concerns equalizing the delays between differently illuminated pixels in an event-based pixel sensor. The sensor comprises an event-based pixel array that detects events associated with changes in illumination and one or more circuits that equalize the delays between pixels. The delay circuits apply different amounts of delay based on levels of illumination received by the corresponding pixels.

Key Takeaways:

  • The invention aims to equalize delays between differently illuminated pixels in event-based vision sensors.
  • Conventional cameras have drawbacks such as high data load, slow reaction time, and high power consumption.
  • Dynamic Vision Sensors (DVS) can achieve high temporal resolution, low latency, low power consumption, and high dynamic range with little motion blur.
  • The patent describes a system for equalizing delays in event-based vision sensors.
  • The sensor comprises an event-based pixel array and one or more circuits that equalize the delays between pixels.
  • The delay circuits apply different amounts of delay based on levels of illumination received by the corresponding pixels.
  • The invention addresses the problem of unequal delays between pixels in differently illuminated scenes.
  • The system is well-suited for solar or battery-powered compressive sensing or for mobile machine vision applications.
  • The high temporal resolution allows continuously tracking visual features and overcoming the correspondence problem.
  • The architecture of the DVS allows for high dynamic range and good low-light performance.

Statistics:

  • 2023: The year the invention was filed.
  • December 4, 2023: The date the patent application was filed.
  • July 22, 2025: The date the patent was published online.
  • U.S. Patent Number 12368977: The patent number assigned to Sony Advanced Visual Sensing AG.
  • 20: The number of claims in the patent application.

Sources:

  • Berner, Raphael. Delay equalization in event-based vision sensors. U.S. Patent Number 12368977, filed December 4, 2023, and published online on July 22, 2025.
  • U.S. Patent Application Publication No. US 2008/0135731, by Lichtsteiner et al., entitled Photoarray for Detecting Time-Dependent Image Data.