Thought maybe this would be a fun project to hack together. I've seen a few of the Arduino-controlled laser/water gun projects to not be so worried about that. What I am less certain about is what the best path forward would be for OCR of the footage of the device, coupled with plane detection of the page to estimate the pose of the book on my lap and properly do the trigonometry for the light/laser that gets shined onto the book. If anyone has seem any projects that leverage OCR/voice recognition and microcontroller robotics that I could learn something from as I try this out, I'd greatly appreciate it!
How old is your child?