Complex sentence: Lou Scheimer was an art director for Larry Harmon Pictures during its brief foray into animated television; after Harmon exited the animation business, Scheimer formed Filmation, which went on to be a leading producer of television animation.
Split into simpler sentences: Lou Scheimer was an art director for Larry Harmon Pictures during its brief foray into animated television. After Harmon exited the animation business, Scheimer formed Filmation, which went on to be a leading producer of television animation.