A high-voltage switch comprises one or more high-voltage transistors and a cooling substrate which may be manufactured from an electrically insulating material and on andor through which a cooling medium can flow, wherein the one or more high-voltage transistors are mounted on at least one surface of the cooling substrate. An image of an image display region in which is displayed an uniform image with no pointing image is picked up as an image for differential image generation. 3% by weight of carbon, 2 to 5% by weight of chromium, at least 0. The tokenskeys may be derived directly from the contextual information.