Depth Sensors Around Me

While going about my day-to-day life, I encounter more and more depth sensors. I worked on the original Structure Sensor and I am curious to see how depth sensing gets applied over time. Depth sensors are different than normal cameras. Simplified, normal cameras return a 2D image consisting of the light sensed at each pixel. Depth sensors, using a variety techniques, generally return a 2D image consisting of the distance between the sensor and scene at each pixel. If you're not familiar, I recommend you look at pictures and examples this page. If you point the sensor at a wall 3 meters away, you will get pixels indicating a big flat surface 3 meters away. The technique used by the original Structure Sensor involves structured light. An infrared dot pattern is projected onto the scene. An infrared camera takes pictures of the dots. An algorithm uses the position of dots to know how far away each pixel is from the sensor and generates the aforementioned 2D image (referred to as a "depth map"). Other techniques used include stereo imaging (sometimes combined with structured light) and time-of-flight. Anyway if you're on this page chances are you need no introduction to depth sensors.

Over the last few months I've been taking pictures of random depth sensors and interesting cameras I encounter in day-to-day life. I don't have any real insight about these sensors. If you have any insight, tips, gossip, or details please feel free to email

Hotel Robot

Here is a picture of the sensor package mounted on a hotel robot. I think it delivers room service orders. This was not a particularly fancy hotel. I believe the bottom sensor is an Orbbec. I'm not sure about the top sensor. My camera caught the--probably infrared--light being projected from the top sensor.
Closeup of the aforementioned robot

Vending machine 1

I believe this sensor is for doing face-scan-pay. If you want to buy something in the vending machine, you can (must?) use your Alipay account. To login to your Alipay account, this sensor scans your face.
Overview of vending machine
A closeup of the sensor package of the vending machine

Vending machine 2

I believe this sensor is also for Alipay face-scan-pay, but appears to be a different model. Perhaps the cover may have been damaged - I'm not sure.
Another Alipay face scan depth sensor

Grocery store 1

This is from a Vanguard grocery store. It is very common for grocery stores to have depth sensors in checkout areas. Some depth sensors are mounted in self-checkout areas. This one was mounted in the regular, person-operated checkout. This is for face-scan-pay, probably with WeChat pay. Although there is a grocery store of the same chain that uses a different depth sensor.
5 optical devices on a grocery store face scan pay machine
For the truly curious, I was able to get slow motion video of the projectors firing:

Grocery store 2

This is from a different Vanguard grocery store not far from the first. This Vanguard has self-checkout kiosks. It is a large touch screen with, I believe, an Orbbec depth sensor. Sorry I didn't grab a great pic but I do have a slightly zoomed close-up.
Grocery store self-checkout terminal with a display and embedded depth sensor
Closeup of a depth sensor embedded in a grocery store self-checkout machine

Grocery store 3

Here is yet another grocery store's self-checkout machine. It seems to be a branded Orbbec. This grocery chain is HeMa, owned by Alibaba, which presumably lets you face-scan-pay with Alipay
closeup of a depth sensor in a grocery store self-checkout kiosk

Book store

This is a sensor embedded in the self-checkout kiosk at a book store. I'm not really sure about its function, but I'm guessing face-scan-pay. If I remember correctly, it has a separate QR/bar code scanner like the rest of the self-checkout machines. Look at all that stuff! Pinky finger for scale
Book store self-checkout kiosk depth sensor

Hospital Kiosk

I'm not sure if there is a depth sensor in here, but the amount and variety of cameras caught my attention. And there seem to be some projectors. This hospital kiosk lets you view/print test results, pay bills, and lots of other stuff. There's a lot going on here. There are two different face scanning apparatuses -- one on each side of the display. I've never used them and I don't know why there are two of them, why they have different colors, or what the deal is. Let's get the big picture and then get a look at each side.
A hospital kiosk with a big LED touch screen and two sensor packages on the sides of the touch screen
Side of the hospital kiosk with 4 optical devices. I believe at least 2 of them are cameras, at least one is a projector. Looks like two cameras and two projectors, I think
Let's zoom in on that exposed PCB.
Honestly, not sure what is going on here

Advertising Display

Here's an advertising display. I doubt it's measuring depth - I'm guessing those are two flood infrared LEDs. I also cannot tell exactly how many cameras it has.
Various cameras and infrared light emitting diodes to track people as they watch advertisements - creepy. I named the file taobao-display, but that's because I could not name it advertising, because it gets blocked by uBlock Origin
Last updated 2021-10-07