360° inspection lenses are mainly divided into inner wall lenses and outer wall lenses.

Inner wall lenses are specifically used to inspect items with cavities. For example, bottle caps, the structure and quality of its internal sealing performance has a key impact; cups of water may exist inside the defects, hygiene issues need to be captured by the inner wall lens; screws of the internal quality of the thread can also be clearly presented through the inner wall lens. The cavity characteristics of these items determine the need for special lenses to go deep inside for comprehensive inspection, and the inner wall lens can meet this need, ensuring that no detail that may affect product quality will be missed.

The exterior lens focuses on the full range of product appearance inspection. For example, batteries can be inspected for the quality of logo printing on the surface and the presence of scratches on the shell; medicine bottles can be inspected for the clarity of labelling characters and the presence of cracks on the surface; and beverage caps and plastic caps can be inspected for the integrity of their appearance and the accuracy of their surface patterns and text. The outer wall lens can scan the appearance of these products 360° without dead angle, accurately identify the surface characters and defects, to ensure that the appearance of the product quality in line with the standard.

Key Selection Parameters

First, the resolution

High resolution lenses are required for products that need to detect tiny characters or subtle imperfections, such as small print instructions on a medicine bottle or tiny scratches on the surface of a battery. High resolution lenses can present these details more clearly and avoid misjudgments caused by insufficient resolution. In general, based on the smallest target size to be detected, the smaller the target, the higher the required lens resolution. For example, the detection of 0.1mm size characters, it is necessary to lens resolution to the level that can clearly distinguish the size of the object.

Second, the focal length

Focal length affects the imaging distance and field of view of the lens. For the inner wall of the lens to detect smaller cavities (such as small-sized bottle caps), a shorter focal length may be more appropriate, so that a clear image can be obtained in the limited internal space. For outer wall lenses to inspect larger sized products (e.g., large pill bottles), a longer focal length may be needed to ensure that the entire product exterior is included in the inspection field of view. At the same time, the focal length is also related to the working distance, which needs to be considered comprehensively.

Third, the field of view

The field of view determines the scope of the lens can be detected at a time. In 360 ° inspection, if the product size is large and need to detect the entire circumference of the surface at once, you need a larger field of view of the lens. However, too large a field of view can lead to distortion of the image at the edges, so this has to be balanced against the actual shape of the product and the inspection requirements. For example, for round beverage lids, an appropriately large field of view can cover the entire circumference, but attention should be paid to the quality of the imaging of the edges to ensure that characters and defects can also be accurately identified at the edges.

Fourth, the working distance

The working distance is the distance from the front of the lens to the surface of the object being detected. For the inner wall lens, due to the deep cavity inside, the working distance is limited by the size of the cavity. While the outer wall lens in the choice of working distance, to consider the production line product transmission mode and positional stability. The appropriate working distance to ensure that the relative position of the lens and the product in the detection process is constant, to obtain stable image quality.

Fifth, the suitability of lighting conditions

Lighting has a significant impact on the detection effect. Different product materials and inspection content may require different lighting. For products with a glossy surface (such as plastic cover), may require special lighting angle and intensity to avoid reflections affect the detection. Lenses should be selected for their compatibility with the lighting system to ensure that clear and accurate images can be obtained under the appropriate lighting conditions.