Circadian task light: proving the physics before the styling

The question

Office workers under LED and fluorescent light can drift out of sync with their natural circadian rhythm. The concept was a task light, a lamp head on a linked arm, that also sends a gentle band of light toward the user's eyes to support alertness. The risk was that the studies behind it used big, soft light boxes. Could a lamp deliver enough of the right wavelengths without being uncomfortable or distracting?

What I did

• Built a dark-room test setup with a monitor, desk and chair, and put an optical spectrometer where a seated user's eyes would be.
• Compared two light sources: an existing in-house LED configuration tuned for how pleasant it looked, and a custom chip-on-board module from a circadian-lighting specialist.
• Measured the combined light at the eye, not just the source, because reflections and overlap change what the user actually receives.
• Fed the readings into an academic circadian-response calculator, using standard time-of-day and exposure assumptions.
• Prototyped the surface that faces the user in iterative forms, using aluminum and sheet stock to build reflectors and diffusers that soften the light.

How it came out

Five form factors and two sources, analyzed. The in-house LED configuration, in several form factors, could deliver a biologically meaningful response in an average use case. That supported the product claim without developing a custom light module for mass production. I handed the form-factor studies and calculator results to an industrial designer to find a version that was both attractive and still met the performance numbers.

Along the way

• Supported a production task light launch with the mass-production drawing package and teardown root cause analysis.
• Supported concept work on a reflected-light lamp: alternate production techniques, snap-fit prototype components and a tolerance stack on a linear chain of parts.
• Completed ASME Y14.5 GD&T training.