Grinding device, particularly for coffee or the like, and system for dispensing coffee comprising such a device

A grinding device, particularly for coffee, the grinding device comprising:

• a tank of coffee beans,
• at least one grinding member adapted to grind a quantity of coffee beans to obtain a coffee powder,
• a grain size adjustment device adapted to adjust at least one operating parameter of said grinding member to vary the grain size of said coffee powder, and
• a dispensing opening adapted to deliver said coffee powder towards a container adapted to receive said coffee powder,
• the grinding device further comprises, in correspondence with or downstream of said dispensing opening, an optical grain size sensor adapted to intercept said coffee powder exiting said dispensing opening and to generate at least a signal indicative of the grain size of said coffee powder, the grain size of said coffee powder being selectable by said grain size adjustment device on the basis of said signal indicative of the grain size of said coffee powder,
• wherein said optical grain size sensor comprises a radiation source adapted to generate a radiation which strikes said coffee powder exiting said dispensing opening along an irradiation direction incident to the exit direction of said coffee powder, said optical grain size sensor further comprising at least one front photodiode placed substantially along said irradiation direction on a side opposite to said radiation source with respect to said coffee powder exiting said dispensing opening, said at least one front photodiode generating a first electrical signal dependent on the part of radiation that passes through said coffee powder exiting said dispensing opening,
• said grinding device comprising a processing and control unit connected to said optical grain size sensor configured to receive said first electrical signal of said at least one front photodiode and to process said at least one signal indicative of the grain size of said coffee powder on the basis of at least said first electrical signal.