Blanking Explained
What blanking is, how the blanking bit works in the ILDA status byte, and how blanked transitions appear in laser graphics.
Blanking is how lasers "pick up the pen" to move without drawing. Understanding it helps diagnose visible connecting lines and travel paths.
What Is Blanking?
When drawing separate shapes, the laser must move from one to the next without leaving a visible line. The solution: turn the beam off during travel.
These "laser off" segments are called blanked moves. In ILDA files, each point has a blanking flag indicating whether the laser is on or off.
The Blanking Bit
In the status byte of each ILDA point record, bit 6 controls blanking:
Bit 6 = 1→ Laser OFF (blanked)Bit 6 = 0→ Laser ON
Some software incorrectly interprets the blanking bit as 0 = off, 1 = on. This causes visible lines during jumps. BeamTracer's validation catches this error.
Why Blanking Matters
Without blanking: If you don't blank during jumps, every shape will have visible lines connecting them — turning "AB" into a scribbled mess with lines between letters.
With blanking: Properly blanked files show clean, separated shapes. The scanner travels the same distance, but the laser is off so nothing is visible.
A Blanked Transition
A shape-to-shape transition commonly contains:
- Blank ON at end of current shape
- Hold blanked at the endpoint when the output system needs more off-time
- Travel to next shape (all points blanked)
- Hold blanked at the start position when the scanner needs more settling time
- Blank OFF to start drawing
Repeated blanked records extend the time spent at an endpoint or start position. The useful count depends on point rate, projector response, and color timing; no fixed repeat count works for every system.
Show Scanner Path
Enable the "Show Scanner Path" option in ILDA Viewer to see blanked segments as dashed gray lines. This reveals:
- Where the scanner travels with laser off
- How efficiently shapes are ordered
- Where long jumps occur
Blanking + Stress Heat Map
Combine Scanner Path with Stress Heat Map to compare blanked moves by relative jump distance. Red dashed lines mark the largest coordinate changes in the view; they are not a hardware-safety verdict.
Further Reading
Scanner Load Deep Dive
How BeamTracer calculates scanner load from required PPS and the selected device-profile rate, what its thresholds mean, and how to reduce point demand.
Color Delay Explained
Why laser strokes start dark or draw faint lines between shapes, what the Color delay control does about it, and how to dial it in on your projector.