Dome-shaped light sources are primarily used for visual inspection of reflective, curved, uneven, or undulating surfaces, such as inspecting printing on aluminum foil packaging, the appearance of pharmaceuticals and food, and defects in electronic or hardware components. Their core advantage is that they provide uniform illumination from all directions through the hemispherical diffuse reflection inner wall, thereby eliminating interference from strong light spots, shadows, and surface unevenness, and improving inspection accuracy. 

• Surface defect detection: Suitable for detecting objects with scratches, uneven surfaces, or undulations, such as electronic components, metal parts, or plastic covers.
• Printing and character recognition: It can clearly identify printed text on reflective or curved surfaces, such as cigarette boxes, aluminum foil packaging, or markings on the bottom of cans.
• Complex surface inspection: It is particularly suitable for inspecting spherical, curved, or other curved surfaces, such as for inspecting medicine capsules or ball bearings.
• Reflective object detection: For reflective surfaces such as metal and glass, it can effectively eliminate strong reflections and allow you to see surface details clearly.
• Food and drug appearance inspection: It can evenly illuminate the surface of food or medicine for visual integrity inspection. 

 

Types and characteristics of LED light sources

1. Ring light source

Offering different illumination angles and color combinations to better highlight the three-dimensional information of objects; high-density LED array for high brightness; various compact designs to save installation space; solves the problem of shadows from diagonal illumination; optional diffuser plate for uniform light diffusion. Applications include PCB substrate inspection, IC component inspection, microscope illumination, LCD calibration, plastic container inspection, and integrated circuit marking inspection.

2. Backlight

High-intensity backlighting with a high-density LED array effectively highlights the shape and contours of objects, making it particularly suitable as a microscope stage. Dual-use (red/white) and multi-use (red/blue) backlights can be configured to produce different colors to meet the multi-color requirements of various measured objects. Applications include dimensional measurement of mechanical parts, shape inspection of electronic components and ICs, detection of film stains, and scratch detection on transparent objects.

3. Bar light source

It is the preferred light source for test objects with large square structures; the color can be customized and freely combined according to requirements; the illumination angle and installation are adjustable. Applications include metal surface inspection, image scanning, surface crack detection, and LCD panel inspection.

4. Coaxial light source

It can eliminate shadows caused by uneven object surfaces, thereby reducing interference; part of it adopts a beam splitter design to reduce light loss, improve image clarity, and uniformly illuminate the object surface. It is best suited for scratch detection on highly reflective objects, such as metal, glass, film, and wafer surfaces; damage detection of wafers and silicon wafers; mark point positioning; and packaging barcode recognition.

5. AOI dedicated light source

It features tri-color light illumination from different angles, which can highlight the three-dimensional information of the solder; an additional diffuser board guides the light and reduces reflection; different angle combinations; applicable to circuit board solder inspection.

6. Spherical Integral Light Source

The hemispherical inner wall, with its integrating effect, uniformly reflects light emitted from the bottom 360 degrees, resulting in highly uniform illumination across the entire image. It is applicable to the inspection of curved surfaces, uneven surfaces, arc-shaped surfaces, or highly reflective surfaces such as metals and glass.

7. Linear light source

Ultra-high brightness, using cylindrical lenses for light focusing, suitable for various continuous detection applications on production lines. Dedicated for array camera illumination and AOI (Automated Optical Inspection) applications.

8. Point light source

High-power LEDs, small in size and high in luminous intensity; a replacement for fiber optic halogen lamps, particularly suitable as coaxial light sources for lenses; high-efficiency heat dissipation device significantly extends the lifespan of the light source. Suitable for telecentric lenses, used for wafer inspection, mark point positioning, and wafer and LCD glass substrate calibration.

9. Combined bar light source

With four-sided strip lighting, each side's illumination is independently controllable; the required illumination angle can be adjusted according to the object being tested, making it widely applicable. Applications include PCB substrate inspection, IC component inspection, solder joint inspection, mark point positioning, microscope illumination, packaging barcode illumination, and spherical object illumination.

10. Alignment light source

It is a dedicated light source for alignment on fully automatic circuit board printing machines. The alignment light source is fast, has a wide field of view, high precision, small size, is convenient for detection and integration, has high brightness, and can be equipped with an auxiliary ring light source.