The ATF4
WDI’s ATF4 is a high speed, high accuracy, autonomous digital autofocus sensor. Its “Smart Sensor Architecture” (SSA) incorporates a semiconductor laser, built-in CMOS image sensor, FPGA and microprocessor for fast digital image processing. By projecting a laser dot onto the sample and digitally processing the image, the ATF4 provides fast and accurate measurements of the distance and direction to focus. This information can then be output directly to WDI’s MCM+ or MCZ controller, or to any compatible controller.
High Accuracy At Fast Speeds
WDI’s ATF4 sensors project their focusing laser directly through the objective lens of the microscope. This “Through The Lens” (TTL) technique allows the ATF4 to provide extremely accurate autofocus, with a success rate typically higher than 99%. The ATF4’s on-board digital processing allows it to couple this accuracy with extremely high speeds, typically achieving focus in less than 0.6 seconds.
Tracking Autofocus
The ATF4 continually assesses both the distance and direction to focus, updating its data every 0.5 milliseconds. This allows the sensor to keep samples in focus regardless of whether they are stationary or in motion. This powerful tracking autofocus makes the ATF4 perfect for scanning very large specimens quickly and precisely.
Maximum Flexibility
The ATF4 sensor is designed to automatically adjust its laser intensity as well as the image sensor’s exposure time, allowing it to adapt to a wide variety of specimens, from low reflectivity (down to 1%) to highly reflective (up to 99%). It operates very well on plane reflective surfaces such as glass and unpatterned Si wafer. It is compatible with objective lenses from 2X to 100X magnification, and wavelengths including UV, NUV and NIR. The ATF4 includes Laser Enable ａnd Camera Sync features for automatically suspending the laser.
Easy Integration
All of the sensors in WDI’s ATF family are designed with ease of integration in mind. They are compatible with most types
of infinity corrected microscope objectives. The ATF4 can be purchased as either a stand-alone sensor with analog output, or as full autofocus system, integrated with either WDI’s MCM+ controller for driving an external Z stage or MCZ controller which includes the ability to drive a two-phase stepper motor for Z actuation. All WDI’s ATF sensors have small, standardized footprints and connections, and can output in either analog or digital formats, making them both easy to install and easy to upgrade as application requirements evolve.

ATF4 AUTO FOCUS & SCANNING SENSOR