JP3258920B2 - Inspection method for CD printed surface - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inspection method for inspecting defects (dust adhesion, chipping, unevenness, etc.) on a screen printing portion of a CD label of a compact disk (hereinafter referred to as a CD).

[0002]

2. Description of the Related Art Generally, in order to display recorded contents and the like on a CD, a maker name, a song name, a player name, and the like are screen-printed on the surface thereof (hereinafter, referred to as a CD label). In a CD printing surface inspection device for inspecting whether or not the CD label has a defect (dust adhesion, chipping, unevenness, etc.), before conducting the inspection, using a number of CDs, a non-defective standard Is determined.

[0003] Conventionally, in teaching, a number of teaching CDs, which are used as standards for non-defective products, are selected by manual visual inspection from CDs to be inspected, teaching is performed using the reference CDs, and a threshold is determined. I was

[0004]

Conventionally, when a threshold value is obtained by teaching, once a threshold value has been determined, it has not been possible for an operator to judge the state at that time and correct the threshold value. Inspection machines must be able to handle the threshold criteria that vary from very strict to very loose, depending on the destination of the machine, and must deal with infinitely many patterns on CD labels. In the range of the teaching threshold value set as described above, there is a case where it is not possible to cope with the defect and is determined as a defective product even though it is a good CD.

[0005]

In order to solve the above-mentioned problems, the present invention corrects an initial teaching threshold value obtained in the first teaching in accordance with a change in the image on the printing surface of the CD to be inspected. Is what you can do.

[0006]

According to the present invention, an initial teaching value is corrected by an operator in accordance with an image change of a CD label by judging a state at that time, and a corrected teaching threshold is Y. = AX + b (Y: Teaching threshold after correction, X: Initial teaching threshold, a, b
(Correction coefficient).

[0007]

FIG. 1 shows an embodiment of the present invention in a printed matter inspection apparatus installed in a multicolor printing press for CDs and the like.
The CD (24) loaded from the loading stage (23) into the CD transport tray (22) disposed on the turntable (21) of the printing machine is moved in the transport direction g to the first color printing stage (25). , The second color printing stage (26) is sequentially printed, the printing is completed in the third color printing stage (27), and the inspection stage (28) immediately before the discharge stage (29) is placed on the inspection stage (28). A print image of the CD (24) is taken by the installed area camera (20), and a print defect is determined by the image processing device (31).

FIG. 2 is a flow chart for explaining the principle of the present invention.

FIG. 2 is a flowchart for explaining the flow of teaching in the present invention. Referring to the drawings, before starting a predetermined CD print surface defect inspection,
An area camera (20) picks up an image of several CDs to be inspected that have been printed without incident, performs certain image processing, and determines an initial teaching threshold X (1). Using this initial teaching threshold value X, a print defect inspection of the CD label is started (2). In the inspection flow, the operator determines the printing state of the CD label, determines correction coefficients a and b, and corrects the initial teaching threshold by the following linear equation (4).

Y = aX + b X: Initial teaching threshold Y: Corrected teaching threshold a, b: Correction count The correction counts a and b in the above formula are determined according to the image change of the CD label and input by the operator. (3).

The subsequent inspection process is performed using the new teaching threshold determined by the above correction.

[0012]

The present invention is embodied in the form described above and has the following effects.

By correcting the initial teaching threshold value obtained by the teaching, the teaching threshold value can be flexibly corrected, and the defect rate of the CD can be reduced.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a main configuration used in a CD printing surface inspection apparatus in one embodiment of the present invention.

FIG. 2 is a flowchart illustrating the principle of the present invention.

[Explanation of symbols]

 24 CD to be inspected 30 CD printed surface inspection device X Initial teaching threshold Y Teaching threshold after correction a, b Correction count

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int. Cl. ⁷ , DB name) G01N 21/88-21/95 B41F 33/14 G06T 1/00

Claims (1)

(57) [Claims] 1. Inspection of a printed surface of a CD to be inspected by using a number of CDs in advance before the image defect of the printed surface of the CD to be inspected is inspected and a teaching threshold value to be a non-defective standard of the inspected CD is determined. The initial teaching threshold obtained by the teaching in the apparatus is made to correspond to the image change of the printed surface of the CD to be inspected, and a linear expression Y = aX + b (X: initial teaching threshold Y: corrected teaching threshold a,
b: correction coefficient).
D Printing surface defect device.