Back in the early 1990s scanners were expensive, required special connection hardware, required very expensive software, and required a large footprint on your desk. Most people couldn't justify the cost for the occasional desire to scan something in as an image. However, Logitech accepted the challenge and gave people an option so long as you were willing to accept half a scanner with no drive motor. The Logitech Scanman.
The Scanman came in a variety of models while it was produced, first in black and white and eventually learning how to see in color. The device was still basically the same. Roughly 6 inches across and requiring YOU to drag it backwards across whatever you wanted to scan both (a) in a straight line and (b) at a constant speed. Most people could never meet those requirements, but it didn't stop Logitech from selling tons of these things.
Companies like Kensington and Fellowes added contraptions to their accessory lineups (you know, the companies that made floppy diskette cases, computer locks, and similar items) that would allow you to drag the device in a straight line, at least helping you solve 50% of the problems you encountered.
I was given a Scanman at one point in 1993, a used black and white model. I eagerly plugged it in to my faux 486 system and struggled for a week to make it do anything. The best I got was a squiggly image of a flattened M&Ms package. Yeah, waste of time.
Hitting YouTube shows some people trying new things with the Scanman. Like using it on robots to follow a line in the ground. Yeah, I suppose that's interesting, until it reaches the limit of its six foot power cord. Still, amusing videos to watch.