Patent ID: 8789464

Claim:
A lithographic printing plate support comprising: an aluminum plate; and an anodized film formed on the aluminum plate, micropores extending in the anodized film in a depth direction from its surface opposite from the aluminum plate, wherein each of the micropores has a large-diameter portion which extends to a depth A of 5 to 60 nm from the surface of the anodized film, and a small-diameter portion which communicates with a bottom of the large-diameter portion and extends to a depth of 900 to 2,000 nm from a communication position between the small-diameter portion and the large-diameter portion, wherein the large-diameter portion has a diameter which gradually increases from the surface of the anodized film toward the aluminum plate, an average bottom diameter of the large-diameter portion as measured at the communication position is larger than a surface layer average diameter of the large-diameter portion as measured at the surface of the anodized film, the average bottom diameter is from 10 to 60 nm, and a ratio of the depth A to the average bottom diameter is 0.1 to 4.0, wherein a small-diameter portion average diameter as measured at the communication position is more than 0 nm but less than 20 nm, and wherein a ratio of the small-diameter portion average diameter to the average bottom diameter is up to 0.85.