Patent ID: 7596274

Claim:
A method of inspecting, for each cell, unevenness of a partition wall surface of a cylindrical honeycomb structure having a plurality of cells functioning as passages for fluid and separated from each other by partition walls, the method comprising the steps of: allowing a diffusion light to enter from one end face side of a honeycomb structure by a predetermined lighting means and to exit from the other end face side of the honeycomb structure after passing it through the inside of the cells; allowing the exited diffusion light to pass through a translucent screen disposed on the other end face side of the honeycomb structure to act as a transmitted light; projecting a transmitted image by means of the tone of the transmitted light onto the transmitted light side of the screen; picking up the transmitted image projected on the screen by an imaging means; analyzing by an analyzing means the gray level of the obtained image to inspect for each cell the level of the surface unevenness of the partition walls of the honeycomb structure; and obtaining unevenness data of the partition walls from the obtained image.