In the field of industrial inspection, accurate observation of internal equipment structures and timely detection of hidden defects are core links to ensure production safety and equipment reliability. As the "clairvoyant" of industrial inspection, the optical performance of endoscope camera modules directly determines inspection efficiency and precision. This article takes a 3.6mm diameter industrial inspection endoscope camera module equipped with OmniVision OV9734 CMOS sensor as the research object, focusing on its parameter combination of 10-100mm focus range and 90° DFOV field of view, and analyzes their core advantages in improving inspection efficiency combined with actual industrial inspection scenarios.
Wide Field of View: "Global Control" in Confined Spaces
In industrial inspection scenarios, the internal environment of confined spaces such as pipelines, engine blocks, and precision instrument cavities is complex. If traditional endoscopes have insufficient field of view, frequent adjustment of the lens position is required to cover the inspection area, which not only prolongs the inspection time but also may miss key parts due to operational errors. The 90° DFOV (diagonal field of view) parameter of this module provides a "global vision" solution for confined space inspection.
From a data perspective, a 90° field of view means that at the same detection distance, the horizontal coverage range of the lens is approximately 50% larger than that of a 60° field of view. Taking the inspection of an industrial pipeline with a diameter of 100mm as an example, when the lens is 50mm away from the pipeline inner wall, the 90° field of view can cover a horizontal width of about 86mm at one time, while the 60° field of view can only cover about 57mm. The former can reduce the number of lens movements by nearly 40%. This "large-scale coverage" capability is particularly critical in the inspection of automobile engine blocks - with staggered air passages and oil passages inside the cylinder block, the 90° field of view allows inspectors to grasp the overall direction of the air passage and interface positions through a single observation without repeated lens adjustments, significantly reducing the risk of equipment collision caused by frequent operations (the 3.6mm slim lens diameter of the module is inherently suitable for narrow channels, and the wide field of view further amplifies its spatial adaptability).
At the same time, the module's distortion is controlled within < -20%, avoiding the problem of image edge stretching and distortion common in wide fields of view. When inspecting pipeline welds, the low distortion characteristic ensures that the measurement error of key dimensions such as weld straightness and width is < 3%, providing a true and reliable image basis for defect judgment.
Flexible Focus Range: "Detail Capture" in Multi-Distance Scenarios
Industrial inspection not only requires "seeing the overall picture" but also "seeing details". Different inspection targets have significantly different requirements for observation distance: close-range observation is needed to check micro-defects such as surface cracks and corrosion points of parts, while medium-range observation is required to confirm the assembly relationship of internal equipment structures and pipeline directions. The 10-100mm focus range of this module accurately covers the core demand range of industrial inspection.
The 10mm close-focus capability is a "sharp tool" for micro-defect detection. In the inspection of precision gearboxes, when the lens is 10mm away from the gear tooth surface, combined with 1.4μm×1.4μm pixel size and 1280×720 resolution, it can clearly capture 0.1mm-level tooth surface scratches - this precision fully meets the requirements for tooth surface defect inspection in the ISO 1328-1 gear accuracy standard. The 100mm long-focus range is suitable for medium-range structure observation. For example, when inspecting the gap between the stator and rotor of large motors, the lens can clearly present the overall gap distribution at a distance of 100mm from the target. Combined with the 90° field of view, it can observe more than 3 stator slots at the same time, quickly judging whether there is a problem of uneven gaps.
More importantly, the continuous focusing range of 10-100mm enables a seamless transition between "global - details". During the internal valve inspection, the inspectors can first use a 90° field of view and a 100mm focusing distance to grasp the overall structure of the valve chamber. Once a suspected leakage point is identified, they do not need to change the lens or adjust the equipment position. Instead, they can directly shorten the focusing distance to 10-20mm, and then magnify and observe the wear degree of the sealing surface. This "one lens for two purposes" feature significantly enhances the continuity of the inspection process.
Synergistic Advantages: "Dual Guarantee" of Efficiency and Precision
The parameter combination of 90° field of view and 10-100mm focus range is not a simple superposition of functions but forms a closed-loop inspection logic of "global observation - target locking - detail verification", achieving dual improvements in efficiency and precision.
From the efficiency perspective, their cooperation reduces "invalid operations" in the inspection process. In the inspection of aero-engine turbine blades, traditional modules require adjusting the lens position 5-6 times to complete the inspection of one blade due to narrow field of view and limited focus range. In contrast, this module can lock the entire blade at one time with the 90° field of view and complete continuous inspection of the blade tip (close focus), blade body (medium focus), and blade root (medium focus) by switching the 10-50mm focus range, shortening the single blade inspection time to 1/3 of the original. At the same time, the 4 integrated LED beads in the lens provide uniform illumination, and combined with the light-gathering ability of the F4.0 aperture, ensure stable image brightness within the 10-100mm full focus range (brightness fluctuation < 15%), avoiding repeated shooting due to insufficient light.
From the precision perspective, parameter synergy reduces human errors. In industrial pipeline corrosion inspection, the wide field of view ensures that the corrosion area is not missed, and the 10mm close focus can accurately measure the depth and area of corrosion pits (combined with image analysis software, the measurement error is < 0.05mm); the low distortion characteristic and stable focusing performance keep the image proportion consistent at different distances, providing a reliable benchmark for quantitative analysis of inspection data. In addition, the AA (Active Alignment) process adopted by the module ensures that the alignment accuracy between the lens and the sensor is < 0.01mm, ensuring that the clarity deviation between the center and edge of the image within the full focus range is < 5%, further improving the consistency of detail inspection.
Conclusion
In the context of industrial inspection upgrading towards "high efficiency and precision", the optical parameter design of endoscope camera modules needs to be closely aligned with actual scenario requirements. The 90° DFOV field of view and 10-100mm focus range of this industrial inspection endoscope camera module, through the advantageous combination of "wide field coverage to reduce operation frequency", "full-distance focusing to capture multi-dimensional information", and "parameter synergy to improve process coherence", perfectly adapt to industrial core needs such as confined spaces, multi-distance observation, and high-precision inspection. In the future, with the continuous segmentation of industrial inspection scenarios, such product design ideas of "determining parameters based on scenarios" will become an important direction for endoscope technology iteration.
