janost:
Use a magnifying glass and put the leds at the focal point.Easy and makes a very simple projector.
Yes, that's the kind of thing.
Remember I want to achieve a high pixel count, at least 64x64 but ideally higher than the 128x64 I have now. Clearly 4,096 individual LEDs is impractical, so some POV/scanning technique would be needed.
Another idea I had was to use a 128x64 OLED display and put a magnifying glass above that .