Proximity Sensors of Texas LLC, an affiliate of monetization firm IP Valuation Partners LLC (d/b/a IPVal), has added a fourth defendant to the campaign that it began last October. The NPE sued Apple (6:18-cv-00041) over the same patent, generally related to an apparatus on an object’s surface that emits light and receives back reflected light, that it asserted in the earlier complaints, filed against Huawei, Microsoft, and ZTE. At issue throughout the campaign are the defendants’ smartphones that include proximity sensors, used, for example, to turn off the touchscreen when the phone is close enough to a user’s ear. Now two IPVal affiliates have begun litigating patents from a portfolio of lens technology portfolio received from a Korean monetization firm in October 2017.