Top 10 Global Safety Light Curtain Manufacturers
Why Safety Light Curtain Manufacturers Matter
Safety light curtains are widely used to protect operators from hazardous machine movements while maintaining productivity. However, selecting the right solution often depends not only on technical specifications, but also on the manufacturer's design philosophy, industry focus, and application experience.
This article provides a structured overview of the top 10 global safety light curtain manufacturers, helping engineers, system integrators, and procurement professionals better understand market positioning and selection criteria.
DADISICK – Practical and Flexible Safety Light Curtain Solutions for Machine Safety
Protective Length — Horizontal Detection Range and Scanning Width
Protective Length and Its Role in Monitoring Wide Hazard Openings
· Protective length determines how wide a hazard opening can be monitored by a light curtain.
· Longer protective length requires light curtains with strong beam power and precision optics to prevent signal loss or misalignment.
· For larger openings such as wide conveyors or gantry loaders, engineers often choose a wide scanning range safety light curtain that maintains detection stability across extended horizontal distances without sacrificing beam uniformity.
Wide scanning range devices reduce the need for multiple units or complex overlapping arrangements, simplifying wiring and alignment while maintaining high safety integrity.
Fixed Blanking Function — Static Obstruction Handling
Fixed blanking is a configuration feature that allows specific beams within the protective field to be excluded from safety evaluation when a fixed object permanently blocks part of the detection area and cannot be removed.
Detailed Explanation
In many industrial applications, fixtures, tool holders, machine frames, or structural supports may permanently obstruct a portion of the light curtain field. Without blanking, these constant interruptions would prevent normal operation.
Fixed blanking enables engineers to:
· Programmatically disable specific beam positions during setup.
· Maintain continuous machine operation while other beams remain active for intrusion detection.
· Avoid false trips caused by unavoidable structural components.
Key considerations:
· Fixed blanking must only be applied for objects that are truly fixed and not part of normal material flow.
· A risk assessment must confirm that blanked areas do not create an unintended bypass path that operators could exploit.
· Safety control logic should verify blanking configuration at every startup to ensure ongoing integrity.
This function enhances flexibility without compromising safety when correctly deployed.
Floating Blanking Function — Dynamic Obstruction Handling
Floating blanking allows moving objects within the detection field to be temporarily ignored without disabling beams permanently.
Detailed Explanation
Unlike fixed blanking, floating blanking adapts to scenarios where objects move or change position within the protective field, such as:
· Continuously fed materials on conveyors
· Parts are being transferred or turned during processing
· Automated guided vehicles passing through the safety zone
Key attributes:
· A configurable number of adjacent beams can be allowed to be blocked anywhere within the field.
· This limit is set based on risk assessment and application requirements.
· If the number or pattern of blocked beams exceeds the allowable threshold, the system triggers a safe stop.
Floating blanking is widely used in automation, where operational efficiency requires materials to pass through the safeguarding field while still protecting humans.
Response Time — Dynamic System Timing
Response time is the time interval between a valid beam interruption and the corresponding change in the safety output signal (e.g., the OSSD switching off).
Detailed Analysis
Response time is a fundamental parameter in safety performance and directly influences safety distance calculations. A longer response time requires the light curtain to be installed further from the hazard to ensure the machine stops before any operator can reach the dangerous zone.
Response time varies with:
Protective height (more beams require longer scan time)
Internal processing speed
Safety output type (relay vs OSSD)
System architecture and self-checking logic
When designing safety systems, engineers should always use the maximum specified response time from the product datasheet — not typical values — to ensure conservative safety distance calculations. If a model with fewer beams has a 10 ms response time, a longer model with more beams may have 15 ms or higher. This difference becomes significant when calculating required safety distances.
Self-Checking and Safety Control Concepts
Self-Test Function (Type 2 / Type 4)
Safety light curtains continuously monitor their internal circuits to detect failures.
· Type 2: Periodic self-testing
· Type 4: Real-time self-monitoring (higher safety level)
Type 4 light curtains are recommended for high-risk industrial applications.
Safety Controller and Relay Integration
A safety controller receives the light curtain's output signals and converts them into safety-rated relay or controller signals, ensuring mutual safety interlocking.
For these applications, safety relays designed for machine protection systems are commonly used to achieve reliable emergency stop control.
Dual-Channel Output (OSSD)
Dual-channel outputs provide two independent and synchronized safety signals. If one channel fails, the other immediately triggers a safety stop, ensuring fail-safe operation.
Manual Reset Function
After a safety interruption, the system requires a manual reset to resume operation. This prevents unexpected machine restarts and improves operator safety.
Safety Distance — The Most Critical Calculation
What Is Safety Distance?
Safety distance is the minimum distance between the safety light curtain and the hazardous zone, ensuring the machine stops before an operator can reach danger.
Incorrect safety distance is one of the most common installation mistakes.
Safety Distance Formula (ISO Reference)
Ds = K × T + C
Where:
· Ds = Safety distance (mm)
· K = Human approach speed (mm/s)
· Horizontal installation: 1600 mm/s
· Vertical installation: 2000 mm/s
· T = Total stopping time (s)
· C = Additional distance (mm), depending on resolution
Reference C Values
· Resolution 20 mm → C = 80 mm
· Resolution 30 mm → C = 130 mm
· Resolution 50 mm or above → C = 850 mm
For a deeper understanding of how stopping performance and control reliability contribute to overall system safety, it is essential to consider machine safety performance levels defined under ISO 13849-1.
Conclusion — Turning Terminology into Real Safety
Understanding safety light curtain terminology is not just a technical exercise—it directly affects machine safety, compliance, and operator protection. By mastering concepts such as beam pitch, resolution, protective height, length, and safety distance, engineers can design safer systems and avoid costly safety risks.
As an engineer working in machine safety at DADISICK, this article is written based on real application experience and daily technical support cases. Correct understanding of safety light curtain terminology is the foundation for compliant design, reliable installation, and long-term operational safety.
Related Safety Devices
Beam spacing：40mm
Number of optical axes：20
Protection height：760mm
Safety sensors for machines output (OSSD):2 PNP
Multifunctional safety relay, providing automatic/manual reset configuration and multifunctional configuration DIP switch, used for industrial field monitoring of various signals with high safety requirements.
5m distance, A technique that uses a laser beam to measure distance and create detailed maps of objects and environments.
Used for monitoring places such as safety doors and windows.
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