Visual Labeling Machine Lens Selection Guide: Principles, Applications, and Frontier Technologies

1、 The core role of lenses in visual labeling

Industrial lenses are the "optical brain" of visual labeling machines, and their performance directly affects imaging quality and labeling accuracy. High quality lenses can convert a 0.01mm label offset into clear pixel signals, providing a data foundation for high-precision positioning. According to industry statistics, reasonable lens selection can increase system detection efficiency by more than 30% and reduce defect rates to below 0.1%.

2、 Working principle and key parameters of lens

1. Optical imaging principle

• Focal length formula1/f=1/u 1/v (object distance u, image distance v)

• Visual field calculationFOV=sensor size x working distance/focal length

• Depth of Field ControlDOF=2 x allowable dispersion circle x F value ²

2. Core performance indicators

3、 Comparison of mainstream lens types and characteristics

1. Fixed focus lens

• featureSimple structure and low cost (¥ 500-3000)

• Applicable scenariosA production line with fixed workstations and a single product type

• Accuracy performance± 0.05mm (5-megapixel camera)

2. Zoom lens

• advantageContinuous adjustable focal length (e.g. 5-50mm)

• limitation: Complex mechanical structure, repeated positioning accuracy ± 0.1mm

• Typical ApplicationsMulti variety small batch flexible production line

3. Telescopic lens

• Technical Characteristics：

  • Nearly zero distortion (<0.03%)

  • Constant magnification (error<0.1%)

• cost¥ 8000-50000 (depending on magnification)

• special designBilateral telecentric structures eliminate perspective errors

4. Liquid lens

• innovative technology：

  • Millisecond level autofocus (no mechanical movement required)

  • Dynamic range of working distance ± 20%

• applied value: Solve the problem of defocusing caused by product height fluctuations

4、 Selection Decision Matrix and Industry Applications

1. High precision demand in the electronics industry

• sceneChip QR code labeling (0.5 × 0.5mm)

• configuration scheme：

  • 5x telecentric lens (such as OPT-T5X-90)

  • Resolution 0.005mm/pixel

  • Coaxial lighting system

2. High speed food and beverage production line

• challenge: Height difference of bottle body ± 5mm, speed of 300 bottles/minute

• Solution：

  • Liquid lens (such as Corning Varioptic A-39N0)

  • Auto focus speed<3ms

  • Depth of field extended to ± 8mm

3. Transparent pharmaceutical packaging

• Special requirements: Penetrating the aluminum film of the bubble cover for positioning

• technology portfolio：

  • Near infrared lens (850nm band)

  • Large aperture design (F1.4) enhances light transmittance

  • backlight system

5、 Four cutting-edge technological trends

1. High resolution miniaturization

• trend20 million pixel lens reduces volume by 40% (such as KOWA LM8JC)

• technological breakthroughNon spherical lens molding process

2. Intelligent focusing technology

• AI driven：

  • Real time analysis of image clarity

  • Automatic focal length adjustment (accuracy ± 0.01mm)

• Application CasesMulti layer labeling of automotive components

3. Multispectral Integration

• Technical Solution：

  • Visible light near-infrared dual channel lens

  • Simultaneous detection of surface printing and internal structure

• detection accuracyMaterial differentiation accuracy>99%

4. 3D visual fusion

• Innovative applications：

  • Structured light lens (such as Schneider Kreuznach Xenon)

  • Depth measurement accuracy ± 0.02mm

  • Surface fitting angle deviation<0.1 °

6、 Selection Five Step Practical Guide

Step 1: Clarify the requirements

• Accuracy requirement (± 0.1mm requires a 5-megapixel telecentric lens)

• Working environment (choose wide temperature range -30~80 ℃ for high temperature environment)

Step 2: Calculate optical parameters

• Resolution=Field of View Width/Number of Lateral Pixels in Sensor

• Depth of field ≥ product height fluctuation × 1.5

Step 3: Selection Comparison

Step 4: Compatibility verification

• Interface matching (C/CS/F interface)

• Compatible with camera sensor size (1/1.8 ", 2/3", etc.)

Step 5: On site testing

• Verification of actual imaging resolution

• Continuous 8-hour thermal stability test

7、 Maintenance and optimization suggestions

1. Daily maintenance

• Clean the lenses weekly (using a dedicated lens pen)

• Check the dustproof performance of the sealing ring every quarter

2. Performance monitoring

• The annual attenuation rate of MTF value should be less than 5%

• Distortion rate fluctuation range ± 0.02%

3. Upgrade Path

• The existing system can be equipped with extension pipes to expand the working distance

• Replace the old lens with a high transmittance coated version (increasing transmittance by 15%)

8、 Summary

The scientific selection of lenses is the key to the successful application of visual labeling machines. With the popularization of new technologies such as liquid lenses and AI focusing, traditional optical systems are undergoing an intelligent revolution. It is recommended that companies choose adaptation solutions based on product characteristics, while also paying attention to cutting-edge technologies such as 3D vision and multispectral imaging to meet the challenges of future flexible manufacturing.