Back before I was born my mother worked for a small “Mom and Pop” drycleaners. She stayed friends with the family and would visit them at the store and at their home. So some of my childhood memories from the 1970s are of playing around in a drycleaners store. It obviously had the conveyor belt like in the clip, but it also had a very similar “electric eye” transmitter and receiver pair on the door. I never really given it any thought in decades (especially since early automatic doors had similarly visible sensors) but the FG clip seems to imply that the door sensor is something iconic of drycleaners and not a generic item that might or might not be present at any small store. So what do you say, are photodetectors that set off a chime “a drycleaners thing” from your perspective?
I have been exactly one place that had this type of sensor rigged to beep (and not silently open a door)—this drycleaners. I have been in exactly one drycleaners—this one. So for me the correlation is 100% on a small sample size.
I don’t think they’re a dry cleaner-specific thing. I’ve only walked into a dry cleaning place a handful of times but I’ve seen those alarms all over the place. I think they’re more commonly used in smaller stores that may not notice a customer walking in.
That’s not data, that’s an anecdote.
By your own admission, you don’t even know if any dry cleaners other than the single one you’ve been to and a cartoon, have them.
Every gas station/convenience store.
In fact I associate them with convenience stores. I’ve never seen that at any of the dry cleaners I’ve gone into anywhere.
To fair, I haven’t been in all the dry cleaners everywhere
At my first job after college (around 1993), someone in the record keeping department mentioned to me that they would like an audible indictor to let them know when someone walks through the door.
I looked at some commercially-available systems, but I didn’t like them because they also made a sound when a person exited. I wanted one that only made a sound when someone entered. So I bought two infrared detectors and designed a circuit that did exactly that: it used a couple “one shot” 555 timers to detect the timing difference between the two detectors. (They were staggered when installed.)
