Imaging apparatus, production system, imaging method, program, and recording medium

Patent metadata

Field	Value
Publication number	US-10957003-B2
Application number	US-201615767877-A
Country	US
Kind code	B2
Filing date	Oct 7, 2016
Priority date	Oct 13, 2015
Publication date	Mar 23, 2021
Grant date	Mar 23, 2021

Abstract

An imaging apparatus includes an imaging unit to image an object, an illuminating unit to irradiate light to the object, the illuminating unit having a first light source and a second light source, and a controlling unit. The controlling unit executes a first imaging process for obtaining a first image acquired by imaging, by repetitively executing an imaging operation by imaging the object in a state in which the first light source is off and the second light source is on, during conveyance of the object, a second imaging process for obtaining a second image by imaging the object in a state in which the first light source is on during the conveyance of the object, and a changing-over process for setting a timing for switching from the first imaging process to the second imaging process, on the basis of the first image acquired by imaging.

First claim

The invention claimed is:

1. An imaging apparatus comprising:
(A) an imaging unit that executes imaging operations;
(B) an illuminating unit, wherein the illuminating unit has a first light source having a certain opening and a second light source having an opening smaller than that of the first light source; and
(C) a controlling unit configured to control the imaging unit and the illuminating unit, wherein the controlling unit executes:
(a) a first imaging process for obtaining a first image including an object moving together with a retroreflective mark, by causing the imaging unit to repetitively execute an imaging operation in a state in which the first light source is lit off and the second light source is lit on,
(b) a second imaging process for obtaining a second image including the object, by causing the imaging unit to execute an imaging operation in a state in which the first light source is lit on, and
(c) a changing-over process for setting a timing for switching from the first imaging process to the second imaging process, on the basis of a position of the retroreflective mark included in the first image.

2. An imaging apparatus according to claim 1 , wherein the second light source is arranged near the imaging unit so that the reflected light from the retroreflective mark enters the imaging unit.

3. An imaging apparatus according to claim 1 , wherein, in the first imaging process, the controlling unit obtains a pixel in only a partial region in the image acquired by the imaging.

4. An imaging apparatus according to claim 1 , wherein, in the changing-over process, as an evaluation value, the controlling unit obtains a position of a center of gravity of a pixel brighter than a predetermined luminance, and when the position of the center of gravity lies within a predetermined range, the controlling unit switches from the first imaging process to the second imaging process.

5. An imaging apparatus according to claim 1 , wherein, in the changing-over process, as an evaluation value, the controlling unit obtains a position of a center of gravity of a pixel brighter than a predetermined luminance and obtains an estimated time when the position of the center of gravity moves into a predetermined range on the basis of a change of the position of the center of gravity between frames, and the controlling unit switches from the first imaging process to the second imaging process at a timing when the estimated time is reached.

6. An imaging apparatus according to claim 1 , wherein, in the changing-over process, as an evaluation value, the controlling unit obtains an arithmetic operation value acquired by dividing a sum of values obtained by multiplying coordinate values of the pixel by a luminance by a sum of luminances of the pixels, and, when the arithmetic operation value lies within a predetermined range, the controlling unit switches from the first imaging process to the second imaging process.

7. An imaging apparatus according to claim 1 , wherein, in the changing-over process, as an evaluation value, the controlling unit obtains an area of continuous pixels that are brighter than a predetermined luminance, and, when the area lies within a predetermined range, the controlling unit switches from the first imaging process to the second imaging process.

8. An imaging apparatus according to claim 1 , wherein the controlling unit further executes an outputting process for outputting the image, acquired by imaging by the second imaging process, to an external apparatus.

9. An imaging apparatus according to claim 8 , wherein, in the outputting process, the controlling unit outputs a partial image obtained by cutting out a portion, to which the object has been projected, to the external apparatus.

10. An imaging apparatus according to claim 1 , wherein an area of the mark is greater than an area of an opening of the second light source.

11. An imaging apparatus according to claim 1 , wherein a plurality of marks are provided, and an area of a minimum region, including the plurality of marks, is greater than an area of an opening of the second light source.

12. An imaging apparatus according to claim 1 , wherein three or more of the marks are provided, such that reflected light of three or more of the marks are not aligned on a straight line in the image acquired by the imaging operation executed by the imaging unit.

13. A production system comprising:
an imaging apparatus comprising:
(A) an imaging unit that executes imaging operations;
(B) an illuminating unit, wherein the illuminating unit has a first light source having a certain opening and a second light source having an opening smaller than that of the first light source;
(C) a conveying apparatus for conveying an object; and
(D) a controlling unit configured to control the imaging unit and the illuminating unit, wherein the controlling unit executes:
(a) a first imaging process for obtaining a first image including the object moving together with a retroreflective mark, by causing the imaging unit to repetitively execute an imaging operation in a state in which the first light source is lit off and the second light source is lit on during the conveyance of the object by the conveying apparatus,
(b) a second imaging process for obtaining a second image including the object, by causing the imaging unit to execute an imaging operation in a state in which the first light source is lit on during the conveyance of the object by the conveying apparatus, and
(c) a changing-over process for setting a timing for switching from the first imaging process to the second imaging process on the basis of a position of the retroreflective mark included in the first image.

14. A production system according to claim 13 , wherein the conveying apparatus is a robot that holds and conveys the object.

15. An imaging method of imaging an object moving together with a retroreflective mark, by using an imaging apparatus that comprises an imaging unit, an illuminating unit, and a controlling unit for controlling the imaging unit and the illuminating unit, wherein the illuminating unit comprises a first light source having an opening and a second light source having an opening smaller than the opening of the first light source, the imaging method comprising:
a first imaging step of allowing the controlling unit to cause the imaging unit to obtain a first image including the retroreflective mark, by causing the imaging unit to repetitively execute an imaging operation in a state in which the first light source is lit off and the second light source is lit on;
a second imaging step of allowing the controlling unit to cause the imaging unit to obtain a second image including the object, by causing the imaging unit to execute an imaging operation in a state in which the first light source is lit on; and
a changing-over step for setting a timing for switching from the first imaging step to the second imaging step, on the basis of a position of the retroreflective mark included in the first image.

16. A non-transitory computer-readable storage medium storing a program for causing a computer to execute an imaging method of imaging an object moving together with a retroreflective mark, by using an imaging apparatus that comprises an imaging unit, an illuminating unit, and a controlling unit for controlling the imaging unit and the illuminating unit, wherein the illuminating unit comprises a first light source having an opening and a second light source having an opening smaller than the opening of the first light source, the imaging method comprising:
a first imaging

Assignees

• Canon Kk

Inventors

• Hayashi Tadashi

Classifications

• G01B11/002 Primary

  for measuring two or more coordinates · CPC title

• G06T7/74

  involving reference images or patches · CPC title

• G06T2207/30204

  Marker · CPC title

• B25J9/1697

  Vision controlled systems · CPC title

• G06T2207/10152

  Varying illumination · CPC title