Apparatus for preparing a coffee beverage

An apparatus for preparing a coffee beverage, comprising:

• a lid;
• a plunger;
• an electric actuator;
• a gear mechanism;
• an electric pump;
• a rotary encoder for outputting signals;
• a brewing unit having a brewing chamber that may be closed by said lid and for receiving poured-in coffee grounds, the coffee grounds being compressed by said plunger, wherein said plunger is driven by said electric actuator via said gear mechanism, and wherein compressed coffee grounds are percolated through by heated water fed into said brewing chamber by said electric pump, said brewing chamber having an outlet through which the heated water emerges;
• a stop;
• an ejector mechanism;
• and
• an electronic control device having a memory and controlling said electric actuator based on the signals of said rotary encoder such that said plunger is moved from a filling position for the coffee grounds, while the coffee grounds are being compressed, to a brewing position and then to an ejection position for a coffee compact formed in said brewing chamber by a brewing process, wherein said electronic control device first moves said plunger against said stop in the ejection position for calibrating said rotary encoder, then moves said plunger from the ejection position a predetermined distance in a downward direction to the filling position, a length of the predetermined distance corresponding to a first number of pulses of said rotary encoder stored in said memory of said electronic control device, and in that after a predetermined filling time said electronic control device moves said plunger in an upward direction by a second distance to the brewing position, a length of the second distance corresponding to a second number of pulses of the rotary encoder stored in the memory, and in that after a predetermined brewing period said electronic control device moves said plunger a third distance back to the ejection position from the brewing position, and in the ejection position, the coffee compact is removed by said plunger upon opening said lid, by means of said ejector mechanism.