A hologram recording medium can record an interference pattern to a volume holographic memory at high density. The cleaning article includes: a base sheet; a brush portion provided on one side of the base sheet; and a holding sheet provided on the other side of the base sheet. Alternatively or in combination, in some embodiments, the base may include a metal layer encapsulated between a transparent non-metal upper layer and a non-metal lower layer. A contact angle of the ball can be optionally changed by changing the positions alone of the rolling member rolling surface 11 and the loaded rolling member rolling surface to be machined on one type of the block and the rail. The location of the peak corresponds to the code phase.