MXPA99005559A - Method and apparatus for the inspection of the mouth of containers using infrared energy issued from the recipie fund - Google Patents

Abstract

The present invention relates to the apparatus and method for inspecting a container having an open mouth and a closed bottom spaced from the mouth of the container, while the container is hot by its manufacture, includes a light detector disposed with respect to the container for Examine the bottom of the container through the mouth of the container. The infrared light energy emitted from the bottom of the container and passing through the mouth of the container is directed towards the light detector, and the inside diameter of the container mouth is measured as a function of the light energy directed towards the detector. The light detector even has a calibrated area detector to develop a two-dimensional image of the mouth of the container, and the infrared light energy is directed towards the detector by an array of telecentric lenses. The calibrated area detector is arranged with a camera having an inlet pupil and the arrangement of telecentric lenses has an infinitely calibrated focus directed towards the bottom of the container and a second focus on the entrance pupil of the camera. The calibrated area detector is coupled to an electronic image processor to determine or calculate a circle of the largest diameter that coincides with the two-dimensional image (FIG. 2) of the mouth of the container, and treating said circle as an indication of the inner diameter cash from the recipient's mouth

Description

METHOD AND APPARATUS FOR THE INSPECTION OF THE MOUTH OF CONTAINERS USING INFRARED ENERGY EMITTED FROM THE RECIPIENT'S FUND Field of the Invention The present invention is designed to measure without contact the dimensional parameters of a container, and particularly for an apparatus and a method of measuring the inside diameter of the mouth of a container at the hot end of the manufacturing process of a container. Background and Objective of the "Invention In the manufacture of translucent containers such as clear and colored glass bottles, it is important to keep the dimensional parameters of each container within the design specifications for functional and aesthetic reasons, for example, it is important that the finished of the container, including particularly the mouth of the container, possess desired geometric characteristics such that the container can be accepted by the automatic filling and capping equipment without damaging the equipment, fracturing the container or obstructing the process line. to designate this, it describes "a container inspection system in which the containers are carried in sequence through a plurality of inspection stations in which various geometric characteristics and other properties are measured. In one of these stations, a test is to insert a pin of predetermined size into the mouth of the container. The diameter of the plug is in accordance with the minimum diameter of the mouth of the container to coincide with the container filling equipment, for example. If the plug can not be inserted into the mouth of the container, the container is rejected. In other stations of the inspection system, the dimensional parameters of the container are measured by monitoring the positions of the rollers in contact with the container while the container is rotated. However, inspection techniques that require physical contact with the container are slow, and are subject to the mechanical state of the rollers and pins, for example. The reciprocal movements necessary to bring the pins and rollers to be in contact or not with the container waste substantial amounts of electrical energy. Moreover, the physical contact of the measuring equipment with the container is not desirable for the so-called hot end of the manufacturing process, in which the container is still soft. To address some of the deficiencies of mechanical inspection techniques, US Pat. No. 5,461,228, also assigned to the assignee thereof, describes an apparatus and method of electro-optical measurement of the dimensional parameters of a container, such as the internal diameter of the container. mouth of the container. A light source sends a light energy into the container, and a light detector is arranged with respect to the energy source and the container to receive the light energy transmitted out of the container through the mouth of the container. A telecentric lens directs to the light detector only the light energy transmitted through the mouth of the substantially axial container to the mouth of the container. The light energy is captured through an iris on a matrix array detector, which develops a bi-dimensional image of the container's mouth. The array array detector is coupled to the electronic devices for image processing to determine or calculate a circle of the largest diameter that will fit with the bi-dimensional image of the mouth of the vessel, and taking said circle as indicative of the effective inner diameter from the mouth of the container. In the conventional glassware manufacturing process, the glassware is molded into a single-section machine and then placed while still hot on a linear conveyor to take it to an annealing device. After releasing the tensions inside the annealing device, the glassware is transported to several stations, for inspection, filling and / or packing. The device divides the hot end of the manufacturing process in which the containers are molded from a cold end of the process in which the containers are inspected and packaged. The container mouth diameter measurement techniques described above are specially designed to be used at the cold end of the manufacturing process. However, it is desirable to implement the inspection at the hot end of the manufacturing process so that the information of the containers having undesirable variations can be quickly obtained and the process corrected. It is therefore a general object of the present invention to provide a method and apparatus for inspecting containers particularly for measuring the inside diameter of the container mouth, which can be implemented at the hot end of the production process. When the containers are directed towards the conveyor following the molding process, the containers are hot, emitting radiation in the visible and infrared range. As the containers travel through the conveyor, they gradually cool down, with the cooling range depending only on the thickness of the individual parts of the container. For example, the body of the container and the mouth, which are relatively thin, cool more rapidly than the bottom and base of the container, which are relatively thick. In the past it was proposed to measure the infrared radiation emitted by the container at the hot end of the manufacturing process to determine or indicate the thickness of the walls of the different parts of the container. See, for example, American patents 2,915,638 and 3,356,212. BRIEF DESCRIPTION OF THE INVENTION An inspection method of containers made in a process in which the containers are submerged at elevated temperatures, and then some parts of the container are cooled to different ranges depending on the thickness, is contemplated according to the present embodiment of the invention, the optical inspection of a first part of the container against a base including a second part of the container at a higher temperature than the first part, such that the first part is effectively illuminated by infrared energy from the second part of the The commercial variations in the second part of the container, consisting of variations that commercially affect the acceptance of the container, are identified in a second part of the container as a function of variables in the infrared energy caused by the second part of the container. First part of the vessel is inspected by a light detector which provides an output as a function of optical characteristics of the first part of the container, and the commercial variations are detected as a function of said signals. In a particular application, of the invention for inspecting the open mouth of the container, the light detector is directed to see the bottom of the container through the open mouth of the container to obtain an image of the mouth of the container illuminated by the infrared energy radiated by the bottom of the container. The infrared energy that emerges from the mouth of the container is directed to the detector by telecentric lenses according to the embodiment of the invention, that is, only the radiant energy that emerges axially from the mouth of the container is directed towards the detector. The detector is coupled to an electronic image processor to determine or calculate a circle of diameter so large that it will fit the bi-dimensional image of the mouth of the container, and treating said circle as an indication of an effective inside diameter of the mouth of the container. container. Apparatus for inspecting a container that has an open mouth and a closed bottom spaced from the mouth of the container, while the container is hot due to its manufacture according to another aspect of the present invention, include a light detector disposed with respect to the container for inspecting the bottom of the container through the mouth of the container. The infrared light energy emitted from the bottom of the container and traveling through the mouth of the container is directed towards the light detector and the inside diameter of the container mouth is measured as a function of light energy directed towards the detector. The light detector preferably consists of a sensitive area to develop a two-dimensional image of the mouth of the container, and the infrared light energy is directed towards the detector by the telecentric lenses. The area of the detector is provided with a chamber having an entrance pupil, and the telecentric lenses have a focus to direct infinitely through the bottom of the container and a second focus at the entrance of the camera's pupil. The matrix detector is coupled to an electronic image processor to determine or calculate a circle of sufficiently large diameter that fits within the bi-dimensional image of the mouth of the container, and treating the circle as an indication of the effective diameter of the mouth of the container. Thus, according to another aspect of the present invention, it provides a method and apparatus for inspecting commercial variations in a container, including the dimensional characteristics of the container such as the inside diameter of the container mouth. The method and apparatus according to this aspect of the invention contemplate directing the light energy towards a first portion of the container under inspection, inspecting the first portion of the container with a light detector that provides an output as a function of optical characteristics of the portion of the inspected container, and identifying the commercial variations in the first portion of the container as a function of such output. According to the invention, the illumination step of the first portion of the container is accompanied by a second portion of the container at an elevated temperature in such a way as to transmit the infrared energy towards the first portion of the container and thus in this way effectively illuminate the first portion of the container. portion of the container for inspection.

BRIEF DESCRIPTION OF THE DRAWINGS The invention, together with the additional objective, features and advantages thereof, will be better understood from the following description, the appendix of claims and the accompanying drawings in which: FIG. 1 is a schematic diagram of a non-contact electro-optical system for measuring the inside diameter of the mouth of a container according to a present embodiment of the invention. Fig. 2 is a schematic fragment of the diameter of a portion of FIG. 1 on a larger scale, FIG. 3 is a schematic diagram illustrating the calculation of the effective inner diameter from a bi-dimensional image of the mouth of the container.

Detailed Description of the Modality Figure 1 discloses a glassware production system that includes the apparatus for inspecting or measuring the inside diameter of the mouth of a container in the hot end part of the manufacturing process according to the present embodiment of the invention. The containers are manufactured in a section of the machine individually under the electronic control of the machine. The individual machining section may be as shown, for example, in U.S. Patent 4,362,544. The American patents 4,152,134 and 4,369,052 amply illustrate the electronic control of the machine. The controls produced by the machine are put on a conveyor to take them in a linear sequence to an annealing section. Immediately after they are produced, the containers are hot emitting radiation in the visible and infrared regions. As the containers are transported to the annealing device, the containers are cooled, with the different parts of the containers cooling to different ranges depending on their thickness. For example, the end part of the container near the mouth is relatively thin and cools relatively quickly, while the bottom of the container is relatively thick and cools more slowly. Closely following the machine 18 where the wall and the mouth of the container are relatively cold, the background still has a red glow, emitting radiation in the infrared range of about 0.4 to 100 microns. According to the present invention, a hot and infrared emitting part of the container, such as the bottom, is used as a light source to illuminate a part of the container that will be inspected such as the mouth. A camera is placed on top of the conveyor and facing down to inspect the vessels' mouths while being transported in sequence under the chamber. The camera includes a detector with a commanded DCC area, an inlet pupil, and lenses 32,34 associated with the entrance pupil. The detector responds to infrared energy in the range of 0.4 to 1.1 microns. A telecentric lens is placed between the camera and the containers as they pass in sequence. The telecentric lenses have an initial focus in the direction of the vessels to infinity, and a second focus to the entrance pupil. That is, the camera is placed with respect to the lenses and the entrance pupil is spaced from the lenses by the focal length of the lenses. That is, the entrance pupil with the lenses functions as an iris in combination with the lenses by concentrating essentially only the light rays emerging from the mouth of the container parallel to the container axis, lenses and camera to the detector. In this way, light rays emerging from the mouth of the container in a direction not parallel to the container and the optical axis, and light rays generated by other parts of the container that might still be hot and emit infrared radiation, will be directed by the lenses to another path and not through the pupil, and in this way they are effectively blocked by hitting against the detector. Thus, a clear image of the mouth of the container is focused towards the calibrated area of the detector. The detector is connected to an electronic information processor for scanning the detector and developing a bi-dimensional image of the mouth of the container. As illustrated in FIG.3, the glass that defines the mouth of the container will appear as a dark image against a bright base formed by the infrared light energy transmitted from the bottom of the container through the mouth of the same. This is because the glass of the container reflects or refracts the transmitted light towards the body of the container, this reflectance or refractance of the light can be neither parallel to the optical axis and because of this it is not directed towards the detector. The best techniques for the exploration of a calibrated area and the development of a two-dimensional image of the mouth of the container are disclosed in the American Patent 4,958,223. FIGS. 2-3 show the operation of the invention in connection with a container having a mouth with an obstructed part. As illustrated in FIG. 2, the obstructed part blocks a part "of the light rays coming out of the mouth of the container parallel to the container / optical axis, thus in this way a two-dimensional image is created in the detector and in the processor as illustrated in FIG. Figure 3. The information processor analyzes the image of Figure 3 by calculating a circle of the largest diameter that matches the image of the mouth, including the obstructed part.The calculated circle is then treated as the effective inner diameter of the In the event that said effective diameter is smaller than the desired inner diameter, the information processor sends an appropriate signal to a reject mechanism to remove the container from the conveyor.The information processor is also coupled to a screen for to display to an operator the bi-dimensional image of the vessel under inspection, or other appropriate inspection information.The information processor is also coupled to the electronic control of the machine to control the positioning and the operation of the mechanism in the individual section of the machine such that the correction of the process variations is possible, or to finish the operation of the individual molds or the sections in which the container is manufactured. In this connection, it will be appreciated that the containers are placed in the conveyor by the machine in a predetermined and continuous sequence, and that the section and the molds in which a particular container was originated can be easily determined. See, for example, American Patent 4,762,544. The invention can also be used to measure other parameters and other geometrical characteristics of the container. For example, a so-called "defective container" -axis, a container in which the mouth is obstructed with respect to the optical axis of the inspection apparatus, will produce an image of two circles encircled from the opposite edges of the mouth of the container to the If the effective diameter through these encircled circles is too small, the container can be rejected as a container mouth having a smaller diameter than the desired minimum. be used to detect and reject a container that has the variation called "bird turn" if the variation is large enough to see through the mouth of the container.

Claims (12)

R E I V I N D I C A C I O N S

1. An inspection method for commercial variations in a first part of a container comprising the steps of: directing the light energy towards the first part of the container under inspection, inspecting the first part of the container towards which the light energy is directed with the light sensitive means that provide an output such as a function of optical characteristics of the inspected part of the container, and identification of the commercial variations in the first part of the container as an output function, characterized in that the step to direct the light energy is accomplished by a second part of the high temperature vessel which directs an infrared light energy towards the first part of the vessel.

2. The method described in claim 1, characterized in that the inspection of containers made in a process from which the containers exit at an elevated temperature, and then any of the parts of the container cooled to different ranges as a function of the thickness, the method it comprises the steps of: the optical inspection comprises the first part of the container in opposition to a base including said second part of the container at a higher temperature than the first part, such that said first part is effectively illuminated by the energy emitted by the mentioned second part and (a) the identification of the commercial variations in the second part of the container as a function of variations in said infrared energy caused by said second part of the container.

3. The method described in claim 2, characterized in that step (a) is performed by inspecting the first part of the container with a light-sensitive means that provides an output such as a function of optical characteristics of said first part which is illuminated by said second part, and when said step (b) is performed as a function of said signals.

4. The method described in claim 3, characterized by inspecting a container having an open mouth and a bottom spaced from said mouth, characterized in that step (a) comprises the step of inspecting the bottom of the container through the mouth open to obtain an image of the mouth of the container such that it is illuminated by infrared energy from the bottom of the container.

5. The apparatus for inspecting a container having an open mouth, which comprises: A light source for directing the light energy within the container, and the light-sensitive means arranged with respect to said light source and the container for receiving the light energy transmitted through the mouth of the container, characterized in that the light source comprises a part of the wall of the container at a temperature such that the part of the wall transmits the infrared light energy inside the container and the light sensitive means corresponding.

6. The apparatus described in claim 5, for inspection of a container having an open mouth and a closed bottom spaced from the mouth of the container while the container is hot from its manufacture, the light sensitive means are arranged with respect to the container to see the bottom of the container through the mouth of the container, the means for directing towards the said light-sensitive means the luminous infrared energy emitted by the bottom of the container and passing through the mouth, and the medium ( 38) for the measurement of the inner diameter of the mouth of the container such as a function of the luminous infrared energy directed towards the light-sensitive means.

7. The apparatus described in claim 6, characterized in that the light-sensitive means includes a calibrated detector, and wherein the means directing the light includes telecentric lens means to direct within the calibrated detector only the infrared light energy from the bottom of the vessel that emerges substantially axially through the mouth of the container.

8. The apparatus described in claim 7, characterized in that the light sensitive means include a chamber having an inlet pupil, and characterized in that the telecentric lens means has an infinite calibration directed toward the bottom of the container and a second calibration to the entrance pupil.

9. The apparatus described in the claim characterized in that the light detector includes a detector with a calibrated area and the means coupled to the detector to develop a two-dimensional image (FIG 3) of the BOCA of the container.

10. The apparatus described in the claim 9, characterized in that the measuring means include means for analyzing the image to determine the inner diameter of the mouth of the container.

11. The apparatus described in the claim 10, characterized by the means of analysis that include the means to determine the circle of the larger diameter that would fit with the image.

12. The apparatus described in the claim 11, characterized in that it includes means for indicating the acceptability of the container as a function of the larger diameter circle. Summary of the Invention The apparatus and method for inspecting a container having an open mouth and a closed bottom spaced from the mouth of the container, while the container is hot by its manufacture, includes a light detector arranged with respect to the container to examine the bottom of the container through the mouth of the container. The infrared light energy emitted from the bottom of the container and passing through the mouth of the container is directed towards the light detector, and the inside diameter of the container mouth is measured as a function of the light energy directed towards the detector. The light detector even has a calibrated area detector to develop a two-dimensional image of the mouth of the container, and the infrared light energy is directed towards the detector by an array of telecentric lenses. The calibrated area detector is arranged with a camera having an inlet pupil and the arrangement of telecentric lenses has an infinitely calibrated focus directed toward the bottom of the container and a second focus on the entrance pupil of the camera. The calibrated area detector is coupled to an elctronic image processor to determine or calculate a circle of the largest diameter that will coincide with the two-dimensional image (FIG. 2) of the mouth of the container, and treating said circle as an indicative of the effective inner diameter of the mouth of the container. C: \ 16938