
Why this display?
Like all engineering problems, this was the result of numerous constraints. With size and cost being two of the biggest.
First, we wanted to display two individual values at the same time. And we wanted
them as big as possible. We’ve found that in many applications, two digits is plenty.
For example, 65 volts, 27 degrees. But three are better: -
However, we also wanted to be able to display the time or stopwatch function. We had just enough room for a half digit in one display, if we were willing to limit the other display to two digits.
Due to the space requirements, we couldn’t get the sets of digits far enough apart from each other horizontally to avoid confusion. Thus we offset them vertically.
We wanted to include more Icons but were limited by the number of pins and layout constraints on the display glass itself. Oh, we also needed to keep all the pins on one side of the glass for PCB layout reasons.
So the answer is: well, it just happened.

“So, why such a ‘unique’ format for the display?” Good question.