Direct prints from screen with instant photo paper

Has anybody tried to make a print from the Arduboy screen with an instant photo paper? For example Fuji sells under the Instax brand instant photo paper that is developed with OLED. So I am wondering if it would be possible to take such a photo paper, lay it over the screen for a certain amount of time to create a kind of direct print from screen for the Arduboy.

You might now ask what this would be good for. One use for it would be for a bitcoin paper-wallet printer. The private key could be shown as a QR code, which could then be permanently recorded on the instant photo paper.

One issue with traditional paper wallets is that printers can store print data, or have some other impression or image from the last print from which the private key could be reconstructed. With the above outlined process this problem would be eliminated. But it might also be neat to take an impression of a high-score in a game or capture some other screen image displayed on the Arduboy.

One problem would be that the image would be mirrored on the print.

True, but for my application not a problem, because I could display the QR code and even the text version mirrored so that it will come out correctly on the print.

But you also said:

You are correct, it would require a mirror/print function to fully support this. But there may be other solutions. I have never worked with this type of photo paper, but perhaps there is a way to make the back transparent after the print and then one could view it from the back not requiring mirroring the image.

If you want to do this, be aware that there are flipHorizontal() and flipVertical() functions in the Arduboy2 library that make this easy.

Wonderful. That makes it that much easier. But the real question is can the photo paper be properly exposed. And I think to activate the chemical development one has to compress the paper, typically done by sending them through rollers. So some kind of mechanical gadget will probably be necessary.

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Just found out that the Fuji Instax film is exposed from the back. That means there is no need to mirror the screen before exposing the film.

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Send the OLED command 0xA0 or 0xA1

Mirrors the screen.

That’s what the flipHorizontal() and flipVertical() functions in the Arduboy2 library, that I previously mentioned, do.

Another step forward. JollyLook is selling just the development unit for an Instax mini film for $35. It has a hand crank to move a film out of the film cartridge while the film is being compressed between two rollers. (See here https://jollylook.photo/collections/frontpage/products/jollylook-development-processing-unit)

All that remains to be designed is some kind of enclosure for this development unit, and a shutter. Then one can make instant copies of small screens, not just the Arduboy. Should work with phones, too.

One problem could be the distance of film to screen. If no lens is used the film needs to be as close to the screen as possible. A mechanical shutter would add to that distance. The shutter could be done electronically by turning the screen on/off for the necessary amount of time. But there still needs to be some way to cover the front after the exposure and before the printer is lifted from the Arduboy.

A little bit different concept to this, I’ve always thought it would be cool to have some kind of small printer device that uses thermal printer. The actual print head for a thermal printer is tiny the big part is the motor that feeds the paper through. (also having enough battery to provide the amps)

But I think it might be possible to do something very small if you feed the paper through yourself and somehow there is a sensor to tell how fast it is going.

I like the idea - a crank handle thermal printer. Or perhaps spring driven which possibly could stabilize the paper feed speed. Would certainly be a unique printer.