Method and inspection unit for a heating member for an electronic cigarette

Patent metadata

Field	Value
Publication number	US-10888124-B2
Application number	US-201716089608-A
Country	US
Kind code	B2
Filing date	Apr 6, 2017
Priority date	Apr 8, 2016
Publication date	Jan 12, 2021
Grant date	Jan 12, 2021

Abstract

A method for inspecting a heating member for an electronic cigarette is disclosed. The method improves positioning of the heating member with respect to the power electrodes of an electronic cigarette so as to provide a more reliable electrical connection between the heating member and power electrodes. The method includes image processing to calculate a distance between coils of the heating element.

First claim

The invention claimed is:

1. A method for inspecting a heating member being part of a cartridge of a device for generating inhalable vapors from a vaporizable liquid product, the method including the following steps:
processing an acquired image, which is obtained by framing the heating member;
identifying in the processed image a first closed region being associable to a first group of contact coils of the heating element, the heating element being wound in coils about a wick, the first group of contact coils representing a first contact terminal configured to contact a respective first power electrode of the cartridge;
identifying in the processed image a second closed region being associable to a second group of contact coils of the heating element, the second group of contact coils representing a second contact terminal configured to contact a respective second power electrode of the cartridge;
calculating for the first closed region a respective first reference center of the coils and calculating for the second closed region a respective second reference center of the coils;
calculating a reference center of the heating member being arranged between the first group of contact coils and the second group of contact coils, starting from the first reference center and from the second reference center;
using the reference center of the heating member to couple the first contact terminal and the second contact terminal of the heating member respectively to the first power electrode and the second power electrode of the cartridge, during a production step of the cartridge.

2. The method according to claim 1 , wherein, for each closed region, the steps of calculating the first reference center and the second reference center of the coils include the following steps:
calculating a, respective first center of gravity of the first closed region and a respective second center of gravity of the second closed region,
identifying a respective first outline delimiting the first closed region and a respective second outline delimiting the second closed region;
identifying a first convex quadrangle being inscribed in the first outline and a second convex quadrangle being inscribed in the second outline, the first convex quadrangle being a function of the first calculated center of gravity and the second convex quadrangle being a function of the second calculated center of gravity;
calculating the first reference center of the coils as an intersection between opposite diagonals of the first convex quadrangle and the second reference center of the coils as an intersection between opposite diagonals of the second convex quadrangle, or calculating the first reference center of the coils as a center of gravity of the first convex quadrangle and the second reference center of the coils as a center of gravity of the second convex quadrangle.

3. The method according to claim 2 , wherein, for each closed region, the step of identifying the first convex quadrangle and the second convex quadrangle includes the following steps:
selecting a first upper line and a first lower line being arranged on opposite sides with respect to the first center of gravity, and selecting a second upper line and a second lower line being arranged on opposite sides with respect to the second center of gravity, which are parallel to a longitudinal axis of the wick, wherein the first upper line is arranged at a first upper distance from the first center of gravity and the second upper line is arranged at a second upper distance from the second center of gravity, wherein the first lower line is arranged at a first lower distance from the first center of gravity and the second lower line is arranged at a second lower distance from the second center of gravity;
identifying a first upper set of intersection points between the first outline and the first upper line, and identifying a second upper set of intersection points between the second outline and the second upper line;
identifying a first lower set of intersection points between the first outline and the first lower line, and identifying a second lower set of intersection points between the second outline and the second lower line;
selecting two points of the first upper set of points and two points of the first lower set of points as vertexes of the first convex quadrangle, and selecting two points of the second upper set of points and two points of the second lower set of points as vertexes of the second convex quadrangle.

4. The method according to claim 3 , wherein, for each closed region the step of selecting two points of the first upper set, two points of the first lower set, two points of the second upper set, and two points of the second lower set includes the following steps:
identifying a first central line which is perpendicular to the first upper line and to the first lower line and passes through the first center of gravity, and identifying a second central line which is perpendicular to the second upper line and to the second lower line and passes through the second center of gravity;
identifying a first upper intersection center between the first upper line and the first central line and a first lower intersection center between the first lower line and the first central line, and identifying a second upper intersection center between the second upper line and the second central line and a second lower center between the second lower line and the second central line; selecting, among the first upper set of points, first upper transition points by scanning the first upper line while moving away from a first upper center both in a first direction and in a second direction, and selecting, among the second upper set of points, second upper transition points by scanning the second upper line while moving away from a second upper center both in the first direction and in the second direction, wherein the second direction is opposite the first direction;
selecting, among the first upper transition points, the two points nearest to the first upper center as first two vertexes of the first convex quadrangle, and selecting, among the second upper transition points, the two points nearest to the second upper center as first two vertexes of the second convex quadrangle;
selecting, among the first lower set of points, first lower transition points by scanning the first lower line while moving away from a first lower center both in the first direction and in the second direction, and selecting, among the second lower set of points, second lower transition points by scanning the second lower line while moving away from a second lower center both in the first direction and in the second direction;
selecting, among the first lower transition points the two points nearest to the first lower center as the remaining two vertexes of the first convex quadrangle, and selecting, among the second lower transition points, the two points nearest to the second lower center as the remaining two vertexes of the second convex quadrangle.

5. The method according to claim 4 , wherein said step of processing the acquired image of the heating member includes the following steps:
applying a first filter to the acquired image in order to make the coils of the heating element distinguishable with respect to a background;
applying a second filter to the image transformed by means of the first filter, in order to expand a dimension of each coil of the heating member and obtain a plurality of closed zones having different dimensions; and
selecting two closed zones having the greatest dimensions in the processed image as the first closed region and the second closed region.

6. The method according to claim 3 , wherein said step of processing the acquired image of the heating member includes the following

Assignees

• Gd Spa

Inventors

• Foghetti Claudio
• Ponticelli Vincenzo
• Moretti Carlo
• Sartoni Massimo
• Federici Luca

Classifications

• G01N21/8851

  Scan or image signal processing specially adapted therefor, e.g. for scan signal adjustment, for detecting different kinds of defects, for compensating for structures, markings, edges (G01N21/8806 and G01N21/93 - G01N21/95692 take precedence; optical measurement of dimensions G01B11/00; optical scanning G02B26/10; image transformation G06T3/00; computerised image enhancement G06T5/00; image processing per se for flaw detection G06T7/0002) · CPC title

• A24F40/46 Primary

  Shape or structure of electric heating means · CPC title

• A24F40/70 Primary

  Manufacture · CPC title

• A24F40/10

  Devices using liquid inhalable precursors · CPC title

• A24F40/60

  Devices with integrated user interfaces · CPC title