A question about collimated light and the collimator ?

[Accutronitis]

These diodes have very good focus close to your objective, like a DVD in a Blue Ray. They keep the objective lens very close to the DVD for this purpose. Back in the 1980s, Philips had video disc players with He-Ne lasers in the large optical package that would move the whole sled over a huge disc to play videos. The sleds were metal and about 10 inches by 6 inches. All the optics were on the sled and the player was huge compared to what we have today.

I think i had something like that, i still have the laser discs or should i call them double sided laser "albums" ! lol