The Korea Institute of Machinery and Materials (KIMM), under the Ministry of Science and ICT (President Park Sang-jin), has succeeded in localizing auto-focus equipment for laser processing machines, which was previously entirely dependent on foreign imports.

No Ji-hwan, a principal researcher at the Optical Application Equipment Research Laboratory of the Korea Institute of Machinery and Materials, has localized autofocus equipment for laser processing machines that can improve the performance of machine vision required for defect inspection during display production.

The autofocus function is a feature that adjusts the focus to the subject being observed, just as you adjust the focus to ensure the desired subject appears sharp when taking a photo with a camera. To secure fast and clear images, the key is autofocus technology that rapidly adjusts focus according to changes in the subject.

The research team developed a laser crescent masking displacement measurement technology that can quickly and precisely measure step differences caused by the movement of a display by applying a crescent-shaped mask to a microscope used to inspect defects in large-area displays.

When a crescent-shaped mask is applied during laser beam projection, a sharp laser beam is observed when the target object is in focus, while the beam changes as the convex part of the crescent shifts left or right when the target is out of focus, depending on the object's position. This principle allows for rapid refocusing by enabling verification of how far the target object has moved vertically from the precise focal point.

No Ji-hwan, a principal researcher at the Korea Institute of Machinery and Materials (KIMM), stated, “Autofocus equipment for microscopes and laser processing machines is a technology widely used in the display industry, a key sector for major domestic corporations, yet we have currently relied entirely on imported technology.” He added, “We expect that applying our technology to the manufacturing processes of domestic display and semiconductor equipment will be of great help in enhancing the competitiveness of domestic companies.”

Meanwhile, this research was conducted with support from the Korea Institute for Industrial Technology Evaluation and Management's project 'Demonstration of Laser Technology and Equipment for Ultra-thin Wafer Cutting' (Project Leader: Principal Researcher Sang-hoon Ahn).