Solid-state imagers with integrated scanning circuits offer many advantages over beam-scanned camera tubes in cost, reliability, size, and range of applications. Solid-state electrical imagers are the realization of available methods for organizing and transferring charges from an image-sensing area to electrical readout ports. Surface acoustic waves (SAWs) traveling on a piezo-electric medium have been shown to support charge transfer in a solid-state device: charges can be injected into electric potential wells that travel at the acoustic speed and may be collected at a different location on the surface. The principles of SAW charge-transfer devices (SAW-CTDs) are reviewed. Design concepts are presented for SAW-CTDs and CCD-CTDs for use as electrical or optical waveform recorders and as imaging devices, e.g., streak and framing cameras, operating in single-shot and continuously cycling modes.