Sony Cyber-shot DSC-U20 Digital Camera

Twenty years ago, photography’s film-to-digital transition was well underway. Designers and engineers were pushing the limits of what they could do when freed from the constraint of a roll of film. The landmark iPhone wouldn’t be released for another five years, ushering in the age of everyone having a touchscreen cell phone (and an attached camera) in their pocket. This was the golden age for small digital point-and-shoot cameras, as it was between the age of film and era of ubiquitous phone cameras. In this environment Sony announced an ultra-tiny digital photo camera, the DSC-U20. Some reviewers claimed it was smaller and better than the best film cameras ever made for clandestine espionage, which sounded great but how they could possibly know?

Anyway, when I learned of it I was blown away by how small it was. I remember thinking if I took a canister for 35mm film and made it 150% as long, it would be approximately the same size as a DSC-U20. Enchanted, I had to have one despite its expense, and my income at the time allowed such frivolous purchases. It was small enough to carry every day, a handy camera years before everyone’s cell phones had a little camera.

If we looked at this device today without that historical context, one could be forgiven to think Sony just packed a cell phone camera into a case with battery and called it a day. That would be very, very wrong. It was a marvel of engineering and packaging, with electronics crammed into every available nook and cranny connected by flexible printed circuit boards. Flex PCB is something easily accessible to the electronics hobbyist today, but not twenty years ago.

The sun had since set for compact point-and-shoot digital cameras. Some people still have them and list them on eBay as “rare vintage digital camera” asking hundreds of dollars for them. Feh! Taking one apart is more fun. I brought it to the January 2020 session of Disassembly Academy at Supplyframe Designlab and a team went to work. I was running around as a co-host of the event (taking a few pictures along the way) and as much as I enjoyed sharing my love of taking things apart to see what made them tick, I was a little sad I couldn’t see every minute of this teardown.

The tiny camera took up more and more of the table as it slowly disintegrated through the night.

I took this picture at the end of the night, showing all the major subassemblies. To this day, this is my favorite picture out of all Disassembly Academy projects.

Two of the participants wanted to take a souvenir home each, a request I happily granted.

One participant took home the rear user control subassembly including the display unit. (Top red rectangle.) I had the impression that this tiny screen was one of Sony’s first attempts at a commercial OLED display, but what we saw was consistent with an LCD. Either my memory is faulty, or we have no idea what an early OLED should look like.

Another participant took home the CCD imaging sensor. (Right red rectangle.) Unlike modern cell phones with their CMOS imaging sensors, this camera had a much bulkier and power-hungry CCD as a tradeoff for better image quality.

I took home the rest, planning to take a closer look at the components later. This is the day.

This camera’s component packaging is even more impressive when taking into account of the fact that more than half of the interior volume were consumed by the battery tray (a pair of NiMH AAA recommended to sustain current draw) and a slot for Sony’s proprietary Memory Stick.

The battery terminals are connected to a power control board with many inductors, capacitors, diodes, and transistors visible. A high density BGA IC is in charge of this department.

Significantly more electronic brainpower lives on this main board, with connections to nearly every other flex PCB on the device. The largest chip has a Sony logo and, based on my past experience tearing down Sony products and encountering plenty of their proprietary components, I didn’t bother wasting time trying to look up that chip’s designation of CXD3159 304A38.

Today, white LEDs are bright enough to add light to the scene. They’re not a true flash but they consume far less power and space. This camera predated such high-powered LEDs, so it had a real Xenon flash with capacitor and its own power control board taking up precious volume for the sake of making a bright flash of light.

Here’s the tiny lens assembly, with a lens that can slide on tiny linear guides. Early cell phone cameras had fixed lenses and all the limitations that imposed. More recent cell phone cameras had lens elements that are moved with voice coils.

Not this camera! Four electrical contacts each imply this is a pair of tiny stepper motors for controlling aperture and focus.

One of the two aperture control flaps has been lost.

Focus control motor shaft has a cam for lens position, working alongside an optical end-stop sensor for lens position.

It might be fun to get these motors to run again, but I’m confident the stepper controllers I have on hand for NEMA17 sized stepper motors would instantly burn these little guys up. Even at their lowest current limited setting. I’ll wait until I get my hands on something that can enforce a lower power limit before I try moving these motors.

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