Imaging hybrid photon detectors with minimized dead area and protection against positive ion feedback

Imaging Hybrid Photon Detectors (HPD) have been developed for integration in large area Cherenkov detectors for high-energy physics and astrophysics. The presented designs – developed particularly for the experiments MAGIC, LHCb and AQUA-RICH – comprise very good imaging properties, protection against positive ion feedback and(or) minimum dead area. The underlying innovations are discussed in some detail.