Deformation amount measuring method, program, server device, and system

Patent metadata

Field	Value
Publication number	US-10295332-B2
Application number	US-201615758534-A
Country	US
Kind code	B2
Filing date	Sep 12, 2016
Priority date	Sep 16, 2015
Publication date	May 21, 2019
Grant date	May 21, 2019

Abstract

At least one aspect of the present disclosure directs to a deformation amount measuring method is a method in which a sheet (101) is used that includes a first layer portion (111) having a first pattern (121) that includes a plurality of line drawings extending in a first direction, and a second layer portion (112) overlaid on the first layer portion (111) and having a second pattern (122) that includes a plurality of line drawings extending in a second direction different than the first direction. The method includes the steps of acquiring, from the sheet (101) that has been disposed on a measurement subject, post-deformation image data corresponding to a post-deformation image including a post-deformation moire produced as a result of a post-deformation first pattern (121) and second pattern (122) being overlaid and finding an amount of deformation of the measurement subject on the basis of the post-deformation image data.

First claim

The invention claimed is:

1. A method for measuring an amount of deformation of a measurement subject in which a sheet is used that comprises a first layer portion having a first pattern that includes a plurality of line drawings extending in a first direction, and a second layer portion overlaid on the first layer portion and having a second pattern that includes a plurality of line drawings extending in a second direction different than the first direction;
the method comprising the steps of:
acquiring, by a processor, from the sheet that has been disposed on the measurement subject, reference data on the basis of pre-deformation image data corresponding to a pre-deformation image including a pre-deformation moire produced as a result of the pre-deformation first pattern and the second pattern being overlaid and post-deformation image data corresponding to a post-deformation image including a post-deformation moire produced as a result of the post-deformation first pattern and second pattern being overlaid; and
calculating, by the processor, an amount of deformation of the measurement subject on the basis of the reference data and the post-deformation image data.

2. The method according to claim 1 , wherein:
the first layer portion includes a deformation following portion that follows a deformation of the measurement subject;
the second layer portion includes a non-deformation following portion that does not follow the deformation of the measurement subject;
the sheet further includes a deformation buffering portion that connects the deformation following portion and the non-deformation following portion; and
the step of calculating the amount of deformation of the measurement subject includes a step of finding an amount of deformation of the deformation following portion on the basis of the post-deformation image data.

3. The method according to claim 2 , further comprising a step of:
outputting a deformation amount alarm indicating that the amount of deformation of the deformation following portion has exceeded a reference value when the amount of deformation of the deformation following portion is greater than or equal to a predetermined deformation amount threshold.

4. The method according to claim 2 , wherein:
the step of calculating the amount of deformation of the deformation following portion includes the steps of:
acquiring a first pitch of the pre-deformation moire from the pre-deformation image, and a first angle of inclination with respect to the second direction of extending directions of the pre-deformation moire;
acquiring at least one of a second pitch of the post-deformation moire from the post-deformation image and a second angle of inclination with respect to the second direction of the extending directions of the post-deformation moire;
calculating an amount of change of a pitch of the first pattern using the first pitch and the first angle of inclination and at least one of the second pitch and the second angle of inclination; and
calculating the amount of deformation of the deformation following portion from the amount of change of the pitch of the first pattern.

5. The method according to claim 4 , wherein:
the step of acquiring the first pitch and the first angle of inclination includes a step of:
acquiring a first spatial frequency information that shows a spatial frequency of the pre-deformation image, and calculating the first pitch and the first angle of inclination from the first spatial frequency information; and
the step of acquiring at least one of the second pitch and the second angle of inclination includes a step of:
acquiring a second spatial frequency information that shows a spatial frequency of the post-deformation image, and calculating at least one of the second pitch and the second angle of inclination from the second spatial frequency information.

6. The method according to claim 4 , wherein:
the step of calculating the amount of deformation of the deformation following portion further includes a step of:
acquiring an offset angle between the first direction and the second direction; and
the amount of change of the pitch of the first pattern is calculated further using the offset angle.

7. The method according to claim 6 , wherein:
the step of acquiring the offset angle includes a step of:
calculating the offset angle using the first pitch.

8. The method according to claim 4 , wherein:
the step of calculating the amount of deformation of the deformation following portion includes the steps of:
acquiring both the second pitch and the second angle of inclination;
comparing a first amount of change of the pitch of the first pattern calculated on the basis of the second pitch with a second amount of change of the pitch of the first pattern calculated on the basis of the second angle of inclination; and
outputting an alarm indicating a possibility that the amount of change of the pitch that is calculated contains a mistake when a difference between the first amount of change and the second amount of change is greater than or equal to a predetermined first calculation threshold.

9. The method according to claim 4 , wherein:
the step of calculating the amount of deformation of the deformation following portion includes a step of:
partitioning a pitch change region where the pitch of the line drawings included in the first pattern change between pre-deformation and post-deformation of the deformation following portion, and a pitch constant region where the pitch of the line drawings included in the first pattern do not change between pre-deformation and post-deformation of the deformation following portion; and
the amount of deformation of the deformation following portion is found from the post-deformation moire produced in the pitch change region of the post-deformation image.

10. The method according to claim 9 , wherein:
the step of calculating the amount of deformation of the deformation following portion further includes the steps of:
calculating an amount of movement of the pre-deformation moire and the post-deformation moire in the pitch constant region and estimating the amount of change of the pitch of the first pattern using the amount of movement; and
outputting an alarm indicating a possibility that the amount of change of the pitch that is calculated contains a mistake when a difference between the amount of change of the pitch of the first pattern calculated from the pre-deformation moire and the post-deformation moire produced in the pitch change region, and the estimated amount of change is greater than or equal to a predetermined second calculation threshold.

11. A non-transitory computer readable medium containing a program for measuring an amount of deformation of a measurement subject in which a sheet is used that comprises a first layer portion having a first pattern that includes a plurality of line drawings extending in a first direction, and a second layer portion overlaid on the first layer portion and having a second pattern that includes a plurality of line drawings extending in a second direction different than the first direction;
the program configured to cause a computer to execute the steps of:
acquiring reference data on the basis of pre-deformation image data corresponding to a pre-deformation image including a pre-deformation moire produced as a result of the pre-deformation first pattern and the second pattern being overlaid;
acquiring, from the sheet that has been disposed on the measurement subject, post-deformation image data corresponding to a post-deformation image including a post-deformation moire produced as a result of the post-deformation first pattern and second patter

Assignees

• 3M Innovative Properties Co

Inventors

• Nakayama Tasuku

Classifications

• B32B2270/00

  Resin or rubber layer containing a blend of at least two different polymers · CPC title

• B32B2307/412

  Transparent · CPC title

• B32B27/40

  comprising polyurethanes · CPC title

• B32B2250/03

  3 layers · CPC title

• B32B2419/00

  Buildings or parts thereof · CPC title