System and method for inspecting a transparent cylinder

Abstract

An inspection system having a light source able to illuminate a transparent cylinder, a mask able to block at least part of the light from the light source, the light source and the mask arranged such that, when the transparent cylinder is positioned in the system for inspection, the light source, the mask and the transparent cylinder are substantially aligned along an inspection axis perpendicular to the longitudinal axis of said transparent cylinder and the mask is interposed between the light source and the transparent cylinder to prevent illumination of a first portion of the transparent cylinder having a width smaller than the diameter of the transparent cylinder while allowing illumination of a second portion of the transparent cylinder, the mask configured to provide a contrast with a particle present in the first portion of the cylinder and illuminated by light refracted by the second portion of the cylinder.

Claims

1. An inspection system for detecting a particle on a surface of a transparent cylinder having a longitudinal axis and a diameter, the inspection system comprising: a portable inspection device comprising: a housing, wherein the housing is sized to be manually held by a user; a light source provided within the housing and configured to illuminate a transparent cylinder, and an opaque mask integrated within the housing of the portable inspection device, the opaque mask configured to block at least part of a light coming from the light source, wherein the light source and the opaque mask are arranged such that when the transparent cylinder is positioned near the portable inspection device, the light source, the opaque mask, and the transparent cylinder are substantially aligned along an inspection axis perpendicular to the longitudinal axis of said transparent cylinder, and the opaque mask is interposed between the light source and the transparent cylinder so as to block the light emitted by the light source on a first portion of the transparent cylinder having a width smaller than the diameter of the transparent cylinder while allowing illumination of a second portion of the transparent cylinder by light emitted by the light source, and wherein the light source and the opaque mask are configured so that a particle present on the surface of the transparent cylinder, located in the first portion of said transparent cylinder and illuminated by light refracted by the second portion of the transparent cylinder, is visible by contrast with the opaque mask.

2. The inspection system according to claim 1, wherein the opaque mask is arranged such that the width of the non-illuminated portion of the transparent cylinder ranges from 20% to 80% of the diameter of the transparent cylinder.

3. The inspection system according to claim 1, wherein the opaque mask is arranged such that the width of the non-illuminated portion of the transparent cylinder is equal to 50% of the diameter of the transparent cylinder.

4. The inspection system according to claim 1, wherein the opaque mask is arranged such that the non-illuminated portion of the transparent cylinder is a central portion of the transparent cylinder.

5. The inspection system according to claim 1, wherein the opaque mask is arranged such that the non-illuminated portion of the transparent cylinder extends on a side of the transparent cylinder.

6. The inspection system according to claim 1, wherein the opaque mask is black-colored.

7. The inspection system according to claim 1, wherein the light source generates a white light.

8. The inspection system according to claim 1, further comprising a switch button provided on the housing of the portable inspection device for controlling illumination of the light source.

9. The inspection system according to claim 1, wherein the light source is battery powered.

10. A method to inspect a transparent cylinder having a longitudinal axis and a diameter for detecting a particle on a surface of the transparent cylinder, comprising: providing a portable inspection device comprising: a housing, wherein the housing is sized to be manually held by a user; a light source provided within the housing of the portable inspection device to illuminate the transparent cylinder, and an opaque mask integrated within the housing of the portable inspection device, the opaque mask configured block at least part of a light coming from the light source, aligning the light source, the opaque mask, and the transparent cylinder on an inspection axis, such that the longitudinal axis is perpendicular to the inspection axis and the opaque mask is interposed between the light source and the transparent cylinder so as to block the light emitted by the light source on a first portion of the transparent cylinder having a width smaller than the diameter of the transparent cylinder while allowing illumination of a second portion of the transparent cylinder by light emitted by the light source, and determining if a particle present on the surface of the transparent cylinder, located in the first portion of the transparent cylinder and illuminated by light refracted by the second portion of the transparent cylinder, by contrast with the opaque mask.

11. The method to inspect a transparent cylinder according to claim 10, further comprising rotating the transparent cylinder around the longitudinal axis with regard to the opaque mask and the light source.

12. The method to inspect a transparent cylinder according to claim 10, further comprising arranging the transparent cylinder relative to the opaque mask such that the width of the non-illuminated portion of the transparent cylinder ranges from 20% to 80% of the diameter of the transparent cylinder.

13. The method to inspect a transparent cylinder according to claim 10, further comprising arranging the transparent cylinder relative to the opaque mask such that the width of the non-illuminated portion of the transparent cylinder is equal to 50% of the diameter of the transparent cylinder.

14. The method to inspect a transparent cylinder according to claim 10, further comprising arranging the transparent cylinder relative to the opaque mask such that the non-illuminated portion of the transparent cylinder is a central portion of the transparent cylinder.

15. The method to inspect a transparent cylinder according to claim 10, further comprising arranging the transparent cylinder relative to the opaque mask such that the non-illuminated portion of the transparent cylinder extends on a side of the transparent cylinder.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows a syringe as an example of a transparent cylinder to be inspected with an inspection system according to the present disclosure.

(2) FIG. 2 is a schematic graph of an inspection system according to the present disclosure.

(3) FIG. 3 shows the operating principle of an inspection system according to FIG. 2.

(4) FIG. 4 shows a particle as detected by the inspection system according to FIG. 2.

(5) FIGS. 5A-5C show different possible positions of the mask of the inspection system according to FIG. 2 as regards a syringe according to FIG. 1.

(6) FIG. 6 shows a particle and a scratch as detected with the mask as positioned in FIG. 5C.

(7) FIG. 7 shows a first example of an inspection system according to FIG. 2.

(8) FIG. 8 shows a second example of an inspection system according to FIG. 2.

(9) FIG. 9 shows a third example of an inspection system according to FIG. 2.

DESCRIPTION OF THE INVENTION

(10) FIG. 1 shows a syringe 10 as an example of a transparent cylinder that can be inspected by a system according to the present disclosure. Others examples of transparent cylinders include cartridges, vials as well as bottles and glassware such as glasses, beakers or metering cylinders (not shown). The syringe 10 of FIG. 1 includes a cylindrical transparent barrel 11 having a diameter D, a longitudinal axis A and defining a tubular chamber 12 with two extremities. One of the extremities of the syringe 10 corresponds to a tip 13 used for the injection of medical products and that may be provided with a staked needle or an adaptor for connecting an intravenous line or any other types of connectors. The other extremity of the cylindrical transparent barrel 11 corresponds to a flange 14 used for gripping the syringe 10. The syringe 10 may be made from any transparent material such as glass or plastic, for example polyethylene, polypropylene, polycarbonate or cyclic polyolefin and any combination thereof.

(11) In FIG. 2, a schematic inspection system 100 includes a black mask 110, a light source 120 and acquisition means or arrangement 130. The mask 110, the light source 120 and the acquisition means or arrangement 130 are aligned on an axis B, hereinafter called inspection axis. To perform an inspection, the syringe 10 is placed between the mask 110 and the acquisition means or arrangement 130 so that its longitudinal axis A is perpendicular to the axis B. The acquisition means or arrangement 130 may be any acquisition means or arrangement capable of obtaining an image of the cylinder, for example the eye of an operator or a video camera.

(12) The operational principle of the inspection system 100 according to the present disclosure is described with reference to FIG. 3. As already mentioned, the light source 120, the mask 110, the transparent cylinder under inspection, for example a syringe 10, and the acquisition means or arrangement 130 are aligned on the inspection axis B, the syringe 10 being placed between the mask 110 and the acquisition means or arrangement 130. To that end, the syringe may be supported by a holder (not shown) or handheld by an operator. When the light source 120 is switched on, a portion of the emitted light EL is blocked by the mask 110 and only the peripheral light L passing around the mask 110 thus reaches the syringe barrel 11. Because of the cylindrical shape of the syringe barrel 11, the light is refracted to illuminate particles and for instance, a particle P. As shown in FIG. 4, which shows the syringe and mask from the point of view of the acquisition means or arrangement 130, the illuminated particle P is easily detectable on an image acquired by the acquisition means or arrangement 130, thanks to the black mask that acts as a black background. A rotation of the syringe 10 around its longitudinal axis A or a rotation of the light source, the mask and the acquisition means or arrangement around the longitudinal axis A of the syringe 10 is preferable in order to inspect the whole circumference of the syringe 10.

(13) The width and the positioning of the mask 110 with regard to the light source 120 and the syringe 10 must be chosen in order to block the illumination of 20 to 80% of the diameter of the syringe 10. Preferably, 30 to 70% of the diameter of the syringe 10 are not illuminated, more preferably 50%, as shown in FIG. 4. The dimensions and the positioning of the mask 110 with regard to the light source 120 and the syringe 10 may thus be selected for each specific inspection device according to the size of the transparent cylinders to be inspected. In the same way, the arrangement of the mask 110, the transparent cylinder 10, the light source 120 and the acquisition means or arrangement 130 into the inspection system 100 may be optimized to obtain an acquired image as the one shown in FIG. 4.

(14) Moreover, the mask 110 is preferentially a plain plate, and as such, configured to block incoming light over the entirety of its exposed surface that receives light from the light source.

(15) In addition, FIGS. 5A-5C show different positioning of the mask 110 with respect to the syringe 10, as viewed by the acquisition means or arrangement 130. In FIGS. 4 and 5A, the mask is centered relative to the longitudinal axis A of the syringe 10. This prevents illumination of a central portion of the syringe and this specific configuration is optimal for the detection of glass particles, which are particularly visible in the middle of the transparent barrel 11. In FIGS. 5B and 5C, the mask 110 is decentered radially relative to the longitudinal axis A of the syringe 10 and only covers half of the diameter D, above or below the longitudinal axis A. This position prevents illumination on a half of the diameter D of the longitudinal barrel 11 and allows the detection of both scratches and particles as it will be explained below.

(16) In FIGS. 5A-5C, the mask 110 has the same length as the barrel 11, which allows inspection of the whole barrel length. However, specific applications may require a mask covering only a partial length of the syringe 10.

(17) Furthermore, the mask 110 is preferably positioned parallel to the syringe axis A, although a small deviation may be acceptable.

(18) Finally, the mask 110 is preferably opaque to the light emitted by the light source and black-colored in order to provide the greatest possible contrast with particles P. It may be made from any suitable materials such as metal, plastic, paper or cardboard.

(19) Thanks to the mask 110, the syringe 10 is illuminated on only a limited portion of its diameter D, the mask 110 both blocking part of the light from the light source 120 and acting as a dark background for the detection of illuminated particles. The inspection system 100 therefore provides a simple and reliable way to detect small size particles, for example particles above 300 μm.

(20) In addition to the detection of particles, the configurations of the inspection system as shown in FIGS. 5B and 5C also allow the detection of scratches. Indeed, if the particles remain visible by contrast with the mask 110, the scratches are easily visible under direct illumination, in the portion where the light is not masked by the mask 110. This case is illustrated in FIG. 6 where the acquisition means or arrangement 130 are able to detect simultaneously both a scratch S in the “white” illuminated region and a particle P in the “black” non-illuminated region.

(21) The light source 120 may be any light source producing a homogeneous light. Preferably, the light is a white color light that may be obtained for example with LEDs, halogen bulbs or neon tubes.

(22) In case the acquisition means or arrangement comprise a video camera, the acquired pictures may be processed with commercially available software designed to identify particles and scratches. Such software may also measure the size of the detected defects and help to reject cylindrical containers having unacceptable defects with respect to the targeted quality level.

(23) In a first example of the present disclosure visible in FIG. 7, a portable inspection system 200 includes a light source 220 and an integrated mask 210. The inspection system 200 is further provided with a switch button 201 and integrated batteries (not shown). For example, this portable inspection system 200 may be used manually by an operator for random manual inspections on a manufacturing line. A syringe 10 may be positioned by the operator at the right distance from the inspection device 200 in order to obtain an image as the ones shown in FIG. 4 or 6. The syringe 10 may also be rotated appropriately by the operator to inspect the whole barrel circumference.

(24) In a second example of the present disclosure visible in FIG. 8, an inspection system 300 is set up to inspect syringes 10 on an in-line manufacturing process. Syringes 10 are carried on a transportation system 30 including holders such as plugs 31 able to maintain the syringes in a vertical positioning. The inspection system 300 includes a rotatable axis 301 and a horizontal frame 302. The mask 310, the light source 320 and the acquisition means or arrangement 330 are held by the horizontal frame 302 and aligned on the inspection axis B. When a syringe 10 is presented to the inspection system 300, the light source 320 is switched on and the rotatable axis 301 is motorized by an electric motor (not shown) in order to rotate the mask 310, the light source 320 and the acquisition means or arrangement 330 around the longitudinal axis of the syringe 10. A set of pictures is acquired by the acquisition means or arrangement 330 to inspect the whole circumference of the syringe barrel 11 in a very short period of time without removing the inspected syringe from the in-line manufacturing process. The optimal rotating speed depends on the size of the syringe itself, the size of the defects to be detected as well as the quality and the parameters of the acquisition means or arrangement. For example, 60 images with a 13 MPx camera may be captured in 10 to 20 seconds. A casing (not shown) may be provided around the inspection system 300, to prevent or limit light coming from other sources that may reduce the efficiency of the light source 320, the casing thus enhancing the contrast and the detection quality of the inspection device 300.

(25) In a third example disclosed in FIG. 9, an inspection system 400 is set-up for the automated inspection of a syringe 10. This inspection system 400 is provided with a frame 401 supporting a mask 410, a light source 420 and acquisition means or arrangement 430. The syringe 10 is accommodated on a rotary holder 402 including two axes (not shown) provided with three wheels (only two are visible in FIG. 9, the third wheel being hidden by one the two visible wheels). At least one of the two axes is coupled to an electric motor (not shown) in order to maintain the syringe 10 in rotation, the second axis being either motorized or free to rotate. This rotary holder 402 allows the full rotation of the syringe 10 in order to inspect the whole circumference of the syringe barrel 11. The inspection 430 means may be either a video camera similar to the acquisition means or arrangement 330 or a magnifying glass for a direct visual inspection. The inspection system 400 according to this example is especially adapted for an in-depth inspection of high quality syringes or transparent cylinders before their delivery to customers that will proceed to filling with medical products.

(26) As applicable, all individual features that are shown in the individual embodiments can be combined and/or exchanged with each other without departing from the scope of the disclosure.