Application of large depth of field and telecentric optical path in particle image analysis

1. The role of large depth of field

Depth of field refers to the axial range of an object that can be clearly imaged by an imaging system. In particle analysis, particles may be distributed on different focal planes (such as suspended particles in a flowing liquid or the top/bottom layer of accumulated particles). The large depth of field design can:

Reduce focus error: Even if the particles are not in the same focal plane, they can be imaged clearly at the same time to avoid blur.

Adapt to dynamic scenes: Suitable for continuous capture of moving particles (such as particles in fluidized beds, sprays or fluids).

Simplify operation: No need to adjust the focus frequently, improving analysis efficiency.

2. Key advantages of telecentric optical path

The characteristic of telecentric optical path is that the main light is parallel to the optical axis. Its core advantages are:

Eliminate perspective distortion: Regardless of the distance of the particle from the lens, the image size remains consistent, avoiding magnification error.

High-precision edge detection: Ensure that the particle boundary is clear and sharp, which is convenient for shape analysis and size measurement.

Uniform lighting matching: With the telecentric lighting system, shadow and reflection interference are reduced, and image contrast is improved.

3. Combined with the specific scenario of the application

(1) Batch analysis of widely distributed particles

The particle size range is large: for example, a mixture of particles ranging from micrometers to millimeters. The large depth of field can cover particle layers of different heights, and the telecentric optical path ensures that the size of all particles is measured without distortion.

Tomographic imaging of accumulated particles: avoid blurring of the bottom particles due to insufficient depth of field, and eliminate the occlusion error of the upper particles on the lower imaging.

(2) Dynamic process monitoring

Real-time capture of flowing particles: such as particles in pipeline transportation or dry spray, large depth of field can track fast-moving particles, and telecentric optical path avoids measurement deviation caused by motion blur.

Online detection system: used for real-time quality monitoring on industrial production lines to reduce imaging failures caused by vibration or position offset.

(3) Characterization of complex shaped particles

Non-spherical particles (such as fibers and flake particles): The telecentric optical path eliminates shape distortion caused by tilt or height difference, ensuring accurate extraction of parameters such as aspect ratio and surface roughness.

4. Practical application cases

Pharmaceutical industry: In the detection of drug powder particle size distribution, the telecentric optical path ensures that the size of fine particles (<10μm) and agglomerates are accurately measured.

Mining sorting: Real-time analysis of ore particles on the conveyor belt, large depth of field covers the particle stacking area, and the telecentric optical path avoids edge distortion.

Environmental monitoring: Microscopic imaging of atmospheric particulate matter (PM2.5/PM10) to cope with the challenges of irregular distribution and dynamic floating.

5. Conclusion

The large depth of field and telecentric optical path design significantly improve the reliability and applicability of Winner 300D by expanding the clear imaging range and eliminating geometric distortion. This makes Winner 300D have irreplaceable advantages in complex particle systems, dynamic processes and high-precision measurement scenarios, and is the preferred solution for optical system design in industrial inspection and scientific research.