Most of this year’s big flagship smartphones have already been released, or at least announced, but Sony has been conspicuously quiet about the highly anticipated Xperia Z4. While there has been no shortage of leaks, we still don’t have much official information about the company’s upcoming smartphone. That may change next week, however, as Sony has scheduled a big event in Japan on April 20 where it will announce a new Xperia device, which many expect to be the Xperia Z4.