Patent Document ID: 4872024
Application ID: 07251393
Patent Status: 1

Claim One:
1. A method of inspecting whether a print pattern composed of plural dots printed on an article meets a predetermined standard, comprising the steps of: recognizing the positions of each of the dots of a print pattern of an acceptable print sample which meets the predetermined standard, and quantizing the dots into binary data; producing unit areas around the positions of each of the dots based on said binary data, joining those unit areas which at least partly overlap, into joined area, recognizing the unit areas and joined areas as a reference area, and storing said reference area; detecting the distribution, or number, or both, of the dots in said reference area, and storing the detected distribution, or number, or both, of the dots as dot information of the print pattern of the acceptable print sample; calculating the coordinates of the center of the print pattern of said acceptable print sample based on said binary data, and storing the calculated coordinates; recognizing the positions of each of the dots of a print pattern printed on an object to be inspected, and quantizing the dots into binary data; calculating the coordinates of the center of the print pattern on the object based on said latter binary data, and storing the calculated coordinates; referring to the coordinates of the center of the print pattern on said object and the coordinates of the center of the print pattern of said acceptable print sample, superposing said reference area and said print pattern on said object while bringing said centers into alignment with each other, detecting the distribution, or number, or both, of the dots of the print pattern on said object within said reference area, and storing the detected distribution, or number, or both, of the dots as dot information of the print pattern on said object; and comparing the dot information of the print pattern on said object with the dot information of the print pattern of said acceptable print sample, determining the extent of agreement between the compared dot information, determining whether the print pattern on said object is acceptable, and issuing the result of the determination.