• You wake up in the middle of the night. • Is it time to get up? • Well, you can look at the nightstand clock. • Unless your partner is in the way. • Even then, without your glasses, the time is just a fuzzball of light. • You could ask Alexa, but that’s sure to wake your partner, too.

Article Summaries:

  • Projection clocks project a large digital or analog time display onto a wall or ceiling, eliminating the need for a bedside clock or glasses. The concept dates back to a 1909 UK patent by Roger Russell, which used lightbulbs and a projector lens to cast a translucent analog face onto the ceiling. In 1938 Leendert Prins filed a similar patent, and modern versions typically employ LEDs or LCDs with halogen backlighting, sometimes incorporating rotating drum numbers or other variations. Recent teardowns by hobbyists show how the light source, condenser lens, and display panel combine to create the projected image. DIY projects range from simple lamp‑on‑clock hacks to full LCD or VFD builds, offering a creative way to keep time visible at night.

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