A processing system includes a plurality of chamber walls that define a sealed environment. The labels are to be applied to articles such as glass containers. A multiplier multiplies the video signal consisting of N bits output from the analog-to-digital converter by the correction data consisting of M bits stored in the correction value memory, and outputs a video signal consisting of L bits with which the difference in luminance between display pixels on the display is corrected. A valve metal anode tab having a thickness equal to one or more anode sheet is inserted into a tab notch in one or more stacked anode sheet and joined to the anode sheet stack by laser welding the tab and sheet edges together.