According to legal docs obtained by TMZ ... Ronnie Spates claims he was viciously attacked by 'Black Ink' stars Ryan Henry, Van Johnson, Don Brumfield and Junior Diaz during a December bash in Chicago ... and he says the reality show's production company wanted a fight to break out to make better TV.

Spates claims he was an invited guest minding his own business at the party when Henry, Johnson, Brumfield and Diaz began kicking the crap out of him. He says the brutal beatdown left him licking serious wounds.

Spates claims show producers fueled the party with loads of booze and actively sought to encourage situations that would lead to conflict, verbal spats and physical altercations ... just so they could create explosive content.

TMZ broke the story ... cops were called to the party after it allegedly got violent. Our law enforcement sources say Junior Diaz was accused of sucker punching a guest, presumably Spates. Police say when they arrived at the scene, they found Spates bleeding from the mouth and disoriented, and he was taken to a hospital for stitches.

Spates is suing the reality stars and Big Fish Entertainment over the incident ... and he's seeking a big payday.