Light Curtain or AI Camera? Comparing Press Machine Safety

Press Safety: Light Curtain vs. AI Camera — Which Is More Effective?

Press machines carry the highest limb loss risk in industrial production. Hand entrapment accidents in eccentric and hydraulic presses affect thousands of workers annually. The light curtain has been the standard solution for years, but AI camera safety systems now offer a compelling alternative.

Light Curtain: Proven But Limited

How It Works

A light curtain creates an infrared beam array between a transmitter and receiver positioned in front of the press die area. Any object breaking the beam immediately stops the press.

Advantages

• Decades of field experience and proven reliability
• Type 4 models achieve SIL3/PLe safety levels
• Fast response time
• Wide range of brands and models (SICK, Leuze, Keyence, Omron)

Disadvantages

Muting problem: Light curtains cannot differentiate objects — material passage triggers false stops. This necessitates muting (temporary bypass). Misconfigured muting creates serious safety gaps.

Bypass risk: Light curtain bypassing is a widespread and dangerous problem. Operators may disable light curtains to increase production speed. This is among the leading factors in the most severe accidents.

Single-line protection: Light curtains only protect along a vertical line. They provide no protection when the operator approaches from the sides or below.

Mounting distance: The mounting distance calculated per ISO 13855 may require placement far from the press, negatively affecting production ergonomics.

AI Camera Press Safety System: The Next-Generation Approach

How It Works

The AI camera system uses deep learning models to detect the press operator's hand, arm, and body in real time through camera imagery. When approach to the danger zone is detected, the press is immediately stopped.

Advantages

Hand-material differentiation: AI solves the light curtain's biggest problem through shape-based detection. It doesn't produce false alarms during material passage, eliminating the need for muting.

Cannot be bypassed: Since there's no physical beam, it cannot be physically bypassed. The camera-based system records bypass attempts.

Wide area protection: A single camera can monitor the operator's front, sides, and approach angles. It provides multi-directional protection that light curtains cannot.

Multi-function: Press safety + PPE detection + zone monitoring on the same camera platform. No separate devices needed for each function.

Easy retrofit: ISEE-CAM mounts on existing presses without structural machine modifications. It connects to safety relays or PLCs via dry contact outputs.

Real-World Scenario: The Muting Problem

At an automotive supplier factory with 20 eccentric press lines, light curtains require constant muting adjustments and operators widen muting windows under production pressure.

With an AI camera system, this problem disappears entirely: since the system visually distinguishes hands from material, the muting concept becomes unnecessary. Production speed is maintained while safety levels increase.

Decision Matrix

Criterion	Light Curtain	AI Camera
Hand-material differentiation	No (muting needed)	Yes
Bypass risk	High	Very low
Protection area	Single line	Wide area
Multi-function	No	Yes
Retrofit ease	Medium	High
SIL/PL certification	Type 4 (SIL3/PLe)	Via PLC integration

Conclusion

The light curtain remains a valid solution with its proven reliability. However, muting issues, bypass risks, and single-line protection limitations can create serious safety gaps.

AI camera press safety systems like ISEE-CAM are a strong alternative, especially for facilities experiencing muting problems, high bypass risk, and multi-function needs. Both technologies can also be used together to create a layered safety architecture.

ISEE Vision offers free site surveys for press safety, providing customized solution proposals for your facility.