which were closer to the gun. Electronics in the camera adjusted for this effect by slightly changing the scanning rates. The accumulation and storage of photoelectric charges during each scanning cycle greatly increased the electrical output of the iconoscope relative to non-storage type image scanning devices. In the 1931 version, the electron beam scanned the granules; while in the 1925 version, the electron beam scanned the back of the image plate. History The problem of low sensitivity to light resulting in low electrical output from transmitting or "camera" tubes would be solved with the introduction of charge-storage technology by the Hungarian engineer Kálmán Tihanyi in the beginning of 1925. His solution was a camera tube that accumulated and stored electrical charges ("photoelectrons") within the tube throughout each scanning cycle. The device was first described in a patent application he filed in Hungary in March 1926 for a television system he dubbed "Radioskop". After further refinements included in a 1928 patent application, Tihanyi's patent was declared void in Great Britain in 1930, and so he applied for patents in the United States. Zworykin presented in 1923 his project for a totally electronic television system to the general manager of Westinghouse. In July 1925, Zworykin submitted a patent application for a "Television System" that includes a charge storage plate constructed of a thin layer of isolating material (aluminum oxide) sandwiched between a screen (300 mesh) and a colloidal deposit of photoelectric material (potassium hydride) consisting of isolated globules. The following description can be read between lines 1 and 9 in page 2: The photoelectric material, such as potassium hydride, is evaporated on the aluminum oxide, or other insulating medium, and treated so as to form a colloidal deposit of potassium hydride consisting of minute globules. Each globule is very active photoelectrically and constitutes, to all intents and purposes, a minute individual photoelectric cell. Its first image was transmitted in late summer of 1925, and a patent was issued in 1928. However the quality of the transmitted image failed to impress to H P Davis, the general manager of Westinghouse, and Zworykin was asked to work on something useful. A patent for a television system was also filed by Zworykin in 1923, but this file is not a reliable bibliographic source because extensive revisions were done before a patent was issued fifteen years later and the file itself was divided into two patents