I. Optical Principle Differences Between Double-Telecentric Lenses and Standard Industrial Lenses

1. The double telecentric lens achieves a dual telecentric structure by placing aperture diaphragms simultaneously on both the object-side and image-side focal planes. Combining the telecentric properties of both sides, it delivers dual stability: changes in object position do not alter magnification, and shifts in camera position do not affect imaging quality.

2. Standard Industrial Lens

• Perspective distortion: The farther an object's edge is from the optical axis, the greater the angle of incidence, resulting in the “near large, far small” phenomenon.
   
• Magnification fluctuation: Image size varies significantly with object distance.
   
• Limited distortion control: Conventional lenses exhibit higher distortion rates, particularly noticeable in wide-angle or telephoto scenarios.

II. Application Case Comparison

1. Double-telecentric Lens: A precision-engineered “optical ruler”

• Automotive manufacturing sector：

  • Engine Cylinder Block Inspection: Dual telecentric lenses with a 15mm depth of field and AI algorithms calculate cylinder bore wall aperture roundness (accuracy ±0.005mm), flatness (±0.01mm), and positional deviation in real time, resolving local blurring issues caused by insufficient depth of field in traditional lenses.

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    Gear Profile Measurement: A telecentric ZOOM LENS combined with 3D reconstruction technology generates point cloud data for the entire gear tooth surface. Profile measurement error is ≤±0.008mm, surpassing the precision of traditional gear measuring instruments.

• Electronic Manufacturing Sector:
   
  • PCB Board Inspection: Dual telecentric lenses with 10mm depth of field support Phase Measurement Profiling (PMP) to capture 3D topography of 0402 resistors and BGA solder joints, achieving coplanarity measurement accuracy of ±0.015mm.
     
  • 5G Connector Inspection: Large-aperture telecentric lenses (supporting a 45.7mm diagonal field of view) paired with a 21-megapixel camera achieve sub-pixel-level pin edge positioning (±0.008mm accuracy) within a 30mm depth of field, while simultaneously detecting pin height variations (±0.02mm).

2. Standard Industrial Lenses: The Cost-Effective Choice for General Applications

• Production Line Monitoring:
   
  • Part Identification and Positioning: While standard lenses can measure thickness (accuracy ±0.005mm) and edge curvature (±0.01mm) of smartphone glass covers using a 5mm depth of field, they require multiple focus adjustments to cover different height zones. This efficiency falls short of the “one-click flash measurement” capability offered by dual telecentric lenses.
     
  • Object Contour Detection: When inspecting injection mold cavities, standard lenses require segmented imaging due to insufficient depth of field (only 0.5mm). In contrast, dual telecentric lenses achieve full-dimension measurement in a single pass (accuracy ±0.01mm) through their 20mm depth of field.

Telecentric lenses, with their core advantages of constant magnification, low distortion, and high depth of field, have become the preferred choice in high-precision manufacturing. Conventional industrial lenses, characterized by their low cost and broad applicability, dominate general-purpose scenarios.