Has anyone experimented with optical flow sensors (aka mouse sensors)?
I started thinking about sensing the reflection of the film with a laser diode for picking the sprocket, basically where there is no film (sprocket hole) the laser will not bounce from the film, and it would not count. But then it came a couple of examples of using essentially a mouse as a linear sensor. Wonder if instead of the mouse assembly (sensor + led) one would use the (sensor + laser) to pick up the reflection on the film surface. Food for thought. Here is an example Using a computer mouse as linear sensor - YouTube
Or for that matter using the sensor to accurately measure position from one of the rollers (similar to the patent above).