Fiber optic Light Lines | Designing and Manufacturing Standard Light Lines

FTI manufactures standard lines from .125" to over 4 feet in length. Also shown is the optional cylindrical lens, which can increase intensity by a factor of 10.


Conversion of an optical path from a spot to a line is highly desirable in many scanning applications. It allows a photo detector with a round or square active area to receive input from a long linear array.

In machine vision lighting, an inexpensive projector bulb can illuminate the entire width of a document or web. Light lines are also used frequently to "pick-up" scattered or reflecting light from a laser and rotating mirror combinations.

FTI's concentrates its effort designing and manufacturing custom lines. However, FTI also manufactures standard Light Lines in a wide variety of sizes and shapes, with the following features:

  • Line lengths of .125" (3mm) or less up to lines 4 feet (122cm) long.
  • Excellent fiber packing and alignment using proprietary manufacturing techniques, compares favorably with “wound” lines in quality without associated cost.
  • The standard bundle length of 40" (1M) is suitable for most applications.
  • Fixture holes in the all aluminum, black anodized body assist in mounting.
  • Black anodized aluminum adapter is attached to the PVC covered metal sheathing for durability and long term performance.
  • Ends of the fiber line are flush with the housing.

Design Considerations

When designing a Light Line, it's important to understand the active area of the line must equal the active area of the spot. The usual method of design begins by describing the desired line length. Then, the optimal spot size of the lamp or area of the photo detector is identified, and a line width is calculated to work best with the setup.

For production applications, take into account possible variations in construction of the lamp or detector, which can affect the size or location of the input or sensitive area, and adjust the active area accordingly.

To ensure consistent performance, the fiber nearer the spot (proximal) end should be randomized to minimize inconsistencies of the lamp or detector, and the fiber at the line (distal) end should be parallel, tightly nested and uniformly placed to focus the output beam and maintain uniformity.

FTI uses a unique, proprietary method of creating lines, resulting in a high quality product with minimum labor.

Occasionally an application will require more active area on the line end than the device at the spot end can accommodate. In this case, FTI will manufacture the line using two (or more) inputs with the fiber from both inputs uniformly dispersed throughout the line, maintaining consistent energy distribution. Each input disperses light energy along the entire length of the line.

Sizing Guidelines

Try to select a line length longer than the area you are inspecting; all Light Lines experience light fall-off at each end.

For web scanning applications, 1 input for every 16" (.4M) of line will create a line width of about .015" (.38mm) and an active diameter (spot) of .55" (14mm) - an area most traditional lamps fill with a focused spot. If you're using a strobe, inputs with an active diameter of up to .8" (20mm) could be used, so the line length per input can be doubled.

Of course, your particular application is the overriding determining factor, and your goal should be to optimize line performance, using as little fiber (and the fewest number of inputs) as possible to minimize cost.

To ensure effective application, we work with you to determine exactly what design will best suit your needs. Then, we'll help determine how uniform the response must be across the face of the line for your use. Finally, each spot-to-line is scanned on our automatic transmission fixture to ensure compliance with the developed specification, or it's checked in a custom test fixure you provide (or we design per the requirements). A hard copy record of the results is provided with each part shipped. You'll know the quality of the part when you receive it, and eliminate the time and cost of setup and inspection.


FTI manufactures light lines in multiple configurations and shapes. Dual, triple and quad (or more) heads, unique housing/fixturing shapes and sizes, bundles of varying lengths, fiber of various types, and line widths of varying sizes can be produced to your specifications or one we develop for you. Finally, high heat, vacuum or pressure applications require special consideration.

P/N Line Length Line Width Bundle Length View Diagram
FTISL16854-2 2" (50mm) .035" (.9mm) 40" (1M) Click to view diagram
FTISL16854-6 6" (150mm) .032" (.8mm) 40" (1M) Click to view diagram
FTISL16854-10 10" (254mm) .020" (.5mm) 40" (1M) Click to view diagram
FTISL16854-16 16" (406mm) .012" (.3mm) 40" (1M) Click to view diagram
FTISL16854-24 24" (610mm) .020" (.5mm) 40" (1M) *2 Click to view diagram
FTISL16854-48 48" (1.22M) .015"(.38mm) 40" (1M) *3 Click to view diagram
FTIDL16855-6 6" (150mm) Dual .020" (.5mm) 30" (762mm) legs;
18" (457mm) common.
Click to view diagram

Need more information? Contact Steve Giamundo. Or call us toll free at 1.800.433.5248

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