Patent ID: 7047882

Claim:
A planographic printing plate producing method, comprising the steps of: forming a coating film layer on a surface of at least one of a photosensitive layer or a heat-sensitive layer after forming the at least one of the photosensitive layer or the heat-sensitive layer on a support; providing a protective sheet material and adjusting a moisture content of the protective sheet material by a moisture adjusting device, said moisture adjusting device comprising: a coating film layer moisture adjusting device for adjusting to a target moisture content a moisture content of the coating film layer formed by applying a coating solution to the support, which support is continuously conveyed; a humidity conditioning zone for having the protective sheet material, which is formed in an elongated sheet-shape and is to be adhered to a surface of the coating film layer formed on the support, pass therethrough; humidity conditioning means for adjusting humidity in the humidity conditioning zone; moisture content measuring means for measuring a moisture content of the coating film layer; and humidity conditioning control means for controlling the humidity conditioning means so that the humidity in the humidity conditioning zone becomes a target humidity corresponding to the measured moisture content of the coating film layer measured by the moisture content measuring means and the target moisture content, and adjusting the moisture content of the protective sheet material, which has passed through the humidity conditioning zone, to an adjusted moisture content corresponding to the measured moisture content and the target moisture content; and providing an adhering means disposed at a downstream side of the humidity conditioning zone and continuously adhering the protective sheet material to the surface of the coating film layer.