The princip­le is rather old: sell a high-qua­li­ty pro­duct rela­tively chea­ply, but the con­sum­a­bles requi­red for it rela­tively expen­si­ve­ly. This works very well for razor bla­des, cof­fee cap­su­les or toner car­tridges, for examp­le – and to the annoyan­ce of con­su­mers, of cour­se, espe­cial­ly when the offe­ring of low-pri­ced com­pa­ti­ble con­sum­a­bles is pro­hi­bi­ted by patent law.

Now, patents are a good thing in them­sel­ves, becau­se anyo­ne who invests time and money in the deve­lo­p­ment of new pro­ducts should – qui­te right­ly – also reap the fruits of their invest­ment for a limi­ted peri­od and be pro­tec­ted from imi­ta­tors who want to save their own deve­lo­p­ment costs.

Howe­ver, con­sum­a­bles in many are­as have long been so tech­ni­cal­ly matu­re that genui­ne inno­va­tions are in short sup­ply. This plea­ses the con­su­mer, who hopes for com­pe­ti­ti­on and fal­ling cos­ts, but annoys many a manufacturer.

So what can be done to keep the “ear­ning money on con­sum­a­bles” busi­ness model ali­ve? It’s simp­le: add tech­ni­cal­ly super­fluous but paten­ta­ble fea­tures to the con­sum­a­bles, pre­sent the who­le thing as an inno­va­ti­ve solu­ti­on to a “tech­ni­cal pro­blem,” obtain a “com­pa­ti­bi­li­ty blo­cking patent,” and design the main pro­duct so that it only works with the con­sum­a­ble if the con­sum­a­ble has the inher­ent­ly super­fluous fea­tures. That’s when, for examp­le, the prin­ter asks the car­tridge, “do you have this or that?” (e.g. a sen­sor that mea­su­res some­thing). If the car­tridge says yes, it infrin­ges the patent (unless it is an ori­gi­nal car­tridge), if it says no, unfor­tu­n­a­te­ly the prin­ter can­not work with it. Third par­ties can­not then offer com­pa­ti­ble pro­ducts and con­su­mers are for­ced to buy only from one manufacturer.

Due to spe­cial fea­ture com­bi­na­ti­ons, such com­pa­ti­bi­li­ty blo­cking patents usual­ly pre­sent them­sel­ves at first glance as qui­te com­plex tech­ni­cal solu­ti­ons, but on clo­ser inspec­tion they regu­lar­ly turn out to be an arbi­tra­ry com­bi­na­ti­on of tri­vi­al fea­tures, whe­re the com­bi­ned fea­tures are known per se and the fea­ture com­bi­na­ti­ons do not real­ly impro­ve the consumable.

What fur­ther com­pli­ca­tes the work of exami­ners at the patent offices is ano­t­her typi­cal fea­ture of com­pa­ti­bi­li­ty blo­cking patents: the “tech­ni­cal pro­blem” sup­po­sed­ly under­ly­ing them does not exist in prac­ti­ce for the per­son skil­led in the art. The­re is no actu­al tech­ni­cal pro­blem to be sol­ved. The respec­ti­ve pri­or art is matu­re. Sin­ce the­re is no tech­ni­cal pro­blem, the­re is natu­ral­ly also no pri­or art which the exami­ner could use to deny grant of a patent.

If inven­tors nor­mal­ly want to achie­ve the widest pos­si­ble scope of pro­tec­tion with a patent in order to pro­tect the use of the solu­ti­on in all pos­si­ble varia­ti­ons, the scope of pro­tec­tion of com­pa­ti­bi­li­ty blo­cking patents is usual­ly tiny. They offer no pro­tec­tion from an inno­va­ti­on point of view, as direct com­pe­ti­tors can easi­ly make their own arran­ge­ment of fea­tures out­side the scope of pro­tec­tion. Howe­ver, sup­pliers of low-cost con­sum­a­bles are for­ced to com­ply with the manufacturer’s arbi­tra­ry arrangement.

Com­pa­ti­bi­li­ty blo­cking patents lead the pur­po­se of patent law, to pro­tect inno­va­tions, ad absur­dum. For most start-ups and medi­um-sized com­pa­nies, howe­ver, what still counts are rather basic patents that secu­re key inno­va­tions and also make the com­pa­ny inte­res­ting for investors.