Optical Probe Autofocus Using Wavelength Shift Defocus Detection

The patent segments the detected image into multiple sub-images based on wavelength ranges. The photodetector array captures light across different wavelengths, and the computing device separates these into distinct sub-images (e.g., blue, green, red channels). This segmentation enables lateral shift measurement between wavelength-specific sub-images to determine defocus, achieving high measurement precision while using standard photodetector technology.

The patent makes the imaging system multi-functional by enabling it to simultaneously perform true-color imaging and autofocus detection using the same optical path and photodetector. The system processes the same captured image to generate both color information (through wavelength-based sub-image separation) and focus information (through lateral shift measurement), eliminating the need for separate autofocus hardware and reducing overall device complexity.

The patent merges multiple wavelength ranges into a single imaging process. Instead of using separate light sources or sequential filtering that would cause energy loss, the system uses a broadband light source that illuminates the sample with all visible wavelengths simultaneously. The photodetector array captures the combined reflected light, and computational methods separate the wavelengths to generate sub-images for lateral shift analysis, preserving light energy throughout the process.

The system uses the light reflected from the sample for dual purposes: both forming the true-color image and providing the information needed for defocus detection. The same reflected light that carries color information also contains the lateral shift information needed for autofocus, eliminating the need for additional illumination energy and achieving self-service in terms of light utilization.