CRB Signal Margin and Focus Stability

When CRB signal margin is insufficient, the equipment may not be completely inoperable, but can become unstable during focus startup or after prolonged operation.

Why It Matters

• Weaker signal reduces focus lock success rate
• Optical path contamination and thermal drift amplify the issue
• Replacing boards or laser heads prematurely may lead to misdiagnosis

Suggested Checks

1. Check optical path cleanliness first
2. Compare CRB performance between cold and warm machine states
3. Then verify if Z-axis focus calibration is stable

Conclusion

Stable CRB signal margin reduces repeated focus failures.