US 9,804,099 B2 · Method and device for the detection in particular of refracting defects

Abstract

A method of inspecting containers (3) moving between a linear camera and a light source (7) presents continuous variation of light intensity with a periodic pattern (71) along at least one variation direction (D). According to the method, for each movement increment of the container, a sequence of N successive image lines of the container is acquired cyclically so that for each image line; the container (3) is illuminated by the light source (7); the image line of the container is acquired; and the periodic pattern (71) is shifted for the next line along the variation direction (D). For each increment of the container (3), at least one phase image line is calculated; and the phase image lines (LP(k)) are analyzed.

Claims11

Dependent claims

A method of in-line optical inspection of transparent or translucent containers (3) traveling at a high rate between a linear camera (11) and a light source (7) presenting continuous variation in light intensity with a periodic pattern (71) of spatial period (T) along at least one variation direction (D), the light source and the linear camera (11) being connected to a control and image processing unit (13), said method being characterized by the following steps:

for each movement increment (k) of the inspected container, a sequence of N successive image lines (Li(k)) of the container is acquired cyclically for i lying in the range 1 to N, where N is not less than 3, such that for each image line (Li(k)), the following steps are performed:
illuminating the container (3) with the light source (7);
acquiring the image line (Li(k)) of the container;
and
shifting the periodic pattern (71) for the next line (Li+1(k)) in the variation direction (D) through the distance (T/N);
for each increment (k) of the container (3), calculating at least one phase image line (LP(k)) from the N image lines (L1(k) to LN(k));
and
analyzing the phase image lines (LP(k)) in order to deduce therefrom as a characteristic of the container (3), at least the presence of a light refracting defect or the quality of the distribution of the material constituting the container.

5 more elements

An optical device for high throughput inspection on a production line of transparent or translucent containers (3) moving between a linear camera (11) and a light source (7) presenting continuous variation of light intensity with a periodic pattern of spatial period (T) in at least one variation direction (D), the light source (7) and the linear camera (9) being connected to a control and image processing unit (13), the device being characterized in that:

the light source (7) is suitable for presenting continuous variation of intensity between a dark light level and a bright light level with a periodic pattern (71) of spatial period (T) in at least one intensity variation direction (D);
and in that
the control and image processing unit:
acquires from the linear camera a sequence of N successive image lines (Li(k)) of the container for each movement increment (k), for i varying from 1 to N, with N not less than 3, and repeating the following operations for each image line (Li(K)):
controlling the light source (7) so that the periodic pattern (71) presents the periodic variation of light intensity in a position (Pi);
acquiring the line (Li(k)) of the container;
and
causing the periodic pattern (71) to be shifted for the next line (Li+1(k)) along the variation direction (D) through a distance (TIN), in order to take the position (Pi+1);
calculates, for each increment (k) of the container (3), at least one phase image line (LP(k)) on the basis of the N image lines (L1(k) to LN(k));
and
analyzes the phase image line (LP(k)) in order to deduce therefrom as a characteristic of the container (3), at least the presence of a light refracting defect or the quality of the distribution of the material constituting the container.

8 more elements

Dependencies are inferred from the claim text.

Method and device for the detection in particular of refracting defects

Life of this patent

Method and device for the detection in particular of refracting defects

Life of this patent

Abstract

Claims11