Just because a watch is “digital” doesn’t necessarily mean it’s battery-powered. The term only refers to the type of display — in contrast to analog. Watches with digital or analog displays (or “ana-digi” hybrids) can be driven by any kind of movement, and long before quartz was common watchmakers were making mechanical watches with digital displays, resulting in some unique looks that have the added benefit of exceedingly easy to read.
The technical principle is more or less the same as familiar, traditional watches that use hands to point to stationary numbers around the dial. The difference is that the hands have been replaced by rotating discs, and watch designers often chose to display the numbers within windows (like how the date is typically shown on most modern watches). Using this design, the minutes are easy to read in a widened aperture, but the hour needs to be more clearly and precisely indicated. Therefore, the solution is a complication that causes the hour display to “jump” ahead each hour. You will sometimes see vintage watches with this kind of display called “direct read.”
The “jump hour” complication is now uncommon and therefore usually relegated to relatively high-end watches (an elegant example is here, and a more avant-garde example is here). The mechanism works simply by storing up energy that is then released on the hour to drive the gear forward. This system of discs and apertures gives watch designers a range of creative possibilities. Those below are each examples of different approaches, but yet others will use a digital display for the jumping hour combined with an analog minutes hand, for example. Best of all, there are many vintage examples from relatively unknown Swiss brands, often for some reasonable prices.
Tenor Dorly Direct-Read Digital

What We Like: This is a downright funky watch design from a more or less unknown brand called Tenor Dorly. It dates to around the 1970s and uses a Swiss automatic movement in an interesting two-tone, tank-like case. In the center of the dial are hours and minutes, and the date is displayed at 6 o’clock, much as on many traditional watches, but it all comes together as something quite avant-garde, Art-Deco, and cool. Then there’s that crazy steel bracelet that really will make you feel like you’re in The Jetsons.
From the Seller: This is a very large 36.5mm x 33mm in stainless steel with gold accents. The movement was just cleaned and is accurate.