Ricoh has filed a new patent in Japan for a 4.2mm f/1.8 lens calculated for a 1/1.7″ sensor (23mm equivalent for Q and D10 and 19mm for the Q7). This lens is most likely designed for the Pentax Q mirrorless camera system. If true, this means that Ricoh/Pentax have not abandon the Q system. The last Q related announcement was back in August 2014 when the Pentax Q-S1 camera was announced. Currently there are 8 different Pentax Q lenses:
Via Egami