A CCD imaging element 12 has a two-dimensional array of a plurality of pixels in the horizontal and vertical directions. As a result of improving and devising the forging process and heat treatment process, the crystal grain diameter can be made fine and uniform, and a method of stably manufacturing a Ta sputtering target superior in characteristics can be obtained thereby. The lower clad layer is formed from a silica glass-type material, which is formed using a trialkylsilyl-type compound as an organic source, such that the melting temperature thereof is higher by a predetermined temperature or more than that of the upper clad layer. Determining the local AO at the vertex may be performed using a second technique. The vacuum cleaner assembly includes a housing assembly having a motor connected to a vacuum source, a particulate collection pan interconnected to the housing and a base and an illumination source for illuminating the particulate collection pan. This method prevents erroneous pattern printing due to initial vibration caused by movement of the stage when ink is injected for printing the pattern.