The Focus laser autofocus detection principle is based on laser rangefinding and autofocus technology. These two core principles are explained in detail below.

The principle of laser ranging:

The Focus laser autofocus microscope first emits a laser beam onto the surface of the LED chip to be inspected. When the laser touches the surface of the chip, part of the light is reflected back according to the optical principle of "angle of incidence equals angle of reflection". A sensor inside the system captures this reflected laser light. The system then measures the time difference between when the laser is emitted and when the reflected light is received. Since the speed of light is known, the system can calculate the distance between the laser and the chip surface from this time difference. This distance information is critical for subsequently determining the focus position of the lens, which directly determines the sharpness of the image.

Principle of autofocus:

Autofocus technology is the key to realizing high-precision inspection. In the Focus system, autofocus is realized by adjusting the position of the lens in real time. When the system obtains the distance to the chip surface through laser distance measurement, it will adjust the position of the lens according to this distance information to ensure that the lens is always in the best focus state. In this way, no matter how the position of the chip surface changes, the system can quickly and accurately adjust the lens to maintain clear imaging.

During the autofocus process, the system calculates the distance and direction that the lens needs to move based on the measured distance information, and then precisely controls the movement of the lens through the drive mechanism (e.g., stepper motor). This process is real-time, i.e., the system will continuously adjust the lens position during the detection process to maintain focus.

The POMEAS Focus laser autofocus inspection principle combines laser ranging and autofocus technology to achieve high-precision and high-efficiency inspection of LED chips. This principle not only improves detection accuracy, but also greatly increases detection speed, making large-scale, high-speed LED chip inspection possible.