WO2017196193A1

WO2017196193A1 - System for control of the external surfaces and geometry of objects manufactured on production lines, utilizing peripheral observation at a full 360° angular range

Info

Publication number: WO2017196193A1
Application number: PCT/PL2017/000044
Authority: WO
Inventors: Krzysztof MALOWANY; Marcin MALESA
Original assignee: Ksm Vision Sp. Z O.O.
Priority date: 2016-05-10
Filing date: 2017-04-26
Publication date: 2017-11-16
Also published as: PL229618B1; PL417147A1

Abstract

The subject of the invention is a system for the control of the external surfaces and geometry of objects manufactured on production lines, utilizing peripheral observation at a full 360° angular range, in particular for the automatic quality control of the examined object (2), i.e. closures of liquid containers such as caps or corks. The system according to the invention is equipped with a digital camera (7) with a lens (6), with an illuminator (5) and a pair of mirrors (3.1) and (3.2) put in a casing (4) in such a way that their bottom edge is located below the examined object (2) which, through an opening in the casing, moves between those mirrors together with the container (1) when being transported on a conveyor of a packaging machine, and the rays reflected off the mirrors form the overall image of the examined object at a full angular range.

Description

System for control of the external surfaces and geometry of objects manufactured on production lines, utilizing peripheral observation at a full 360° angular range

The subject of the invention disclosed herein is a system for control of the externa! surfaces and geometry of objects manufactured on production lines, utilizing peripheral observation at a full 360° angular range. In particular, the system is intended for automatic quality control of seals such as corks, caps securing packaging for liquids (bottles, vials, etc.). The construction of the system allows it to perform control on continuous motion production lines.

There are different types of devices for the circumferential observation of objects as they move on production lines.

Patent application no. EP0047936 provides a solution enabling the circumferential view of the peripherally axial symmetrical objects making use of a pair of conical mirrors (concave and convex), which by way of a light beam reflection form an image of the outer surface of the peripherally symmetrical object in the image plane of a camera. The device uses a peripheral illuminator located on the outside of the mirrors.

The solution from patent no. US 752227 describes an optical system for imaging the lateral surface of the examined object in the image plane of an optical system. The system includes optical elements reducing the angle of the light beam reflected from the object.

International patent application no. WO2015185318 describes a device for controlling container closures, particularly caps. The device consists of a lens, an illumination system and a camera. The lens is made up of at least two parts (including an aspherical one), which makes correction of the spherical aberration of the system possible, favourably affecting parameters of the recorded image.

All the solutions mentioned above allow for circumferential view of the lateral and upper surfaces of the objects, but they ignore their bottom surface.

Patent application no. WO2014023580 reveals a device for controlling container closures, including symbols on their top surface. This device equipped with a system of multiple cameras allows for a complex, circumferential view of the closure from several directions. The device makes observation of all the external surfaces of the closure possible, but in order to observe the upper and lateral surfaces of the closure, a separate camera is required to follow the upper surface and a separate set of cameras (at least three) to observe the lateral surface at full angular range.

Patent application no. US2013208105 reveals a device for controlling vessels which are fixedly mounted on a processing machine. The device is made up of a lens-type camera, an illumination system mounted in a stationary casing and a movable mirror which is lowered during the inspection and covers the test element. The applied optical system transforms the circumferential images of the examined surface (upper, lateral and bottom) onto a plane of the camera. This device provides full observation of all the external surfaces of the examined object, however due to the use of a movable element (perpendicularly to the direction of movement of the examined object) this device cannot be used in continuous motion production lines where the examined object is not stopped during the production process. Moreover, the use of the movable element makes the construction of the system excessively complicated.

In patent no. US 8.937.656 a device was revealed which by way of peripheral observation of the caps allows for detecting irregularities on the tamper-evident bands securing the caps. The device is equipped with one camera and a system of mirrors placed in the main casing and four identical cylindrical casings suspended beneath the main casing. Such a construction enables the recording of the image of a cap from four directions with the use of a single camera, providing a circumferential view. The device uses illuminators placed in cylindrical casings. It provides full observation of all the external surfaces of the examined object, wherein the diameter of the cylindrical casings' arrangement determines the size of the field observed by the camera, and the diameter of the cylindrical casing determines the size of the mirrors within, thus indirectly the size of the image recorded by the camera. Four identical cylindrical casings with mirrors are arranged over the circumference of the large diameter, several times greater than the diameter of the examined object and the diameter of the cylindrical casings. It unfavourably influences the imaging system as the images of the examined object (recorded from four directions) are a small part of the image recorded by the camera.

The aim of the invention disclosed herein is to provide a system for control of the external surfaces and geometry of objects manufactured on production lines, utilizing peripheral observation at a full 360^° angular range, in particular for automatic control of the quality of closures (such as caps) of the packaging for liquids {inter alia bottles, vials}, enabling control on continuous motion production lines and free of the faults of the already known solutions.

According to this invention, the system for control of the external surfaces and geometry of objects manufactured on production lines, utilizing peripheral observation at a full 360° angular range, in particular for automatic control of the quality of the element closing the container (such as cap), consisting of a lens- type digital camera, a single illuminator, mirrors and a casing, is characterized in that the casing with an illuminator inside is provided with only one pair of mirrors arranged in such a way that their bottom edge is below the examined object, and the object such as a cap closing a container is transported between the mirrors through an opening in the casing by a conveyor, while the rays reflected off the mirrors image the object being inspected at the full range. According to the invention, it is recommended that two pencils of rays coming out of the entrance pupil of the lens, each of an angle smaller than 180°, after being reflected off the mirrors, form an image of the examined object at the full angular range of 360^° in a cross-section perpendicular to the optical axis of the iens.

At the same time, it is also recommended that the two pencils of rays coming out of the entrance pupil of the lens, after being reflected off the mirrors, image the lateral and bottom surfaces or their part, in a section containing the optical axis of the lens.

It is beneficial to put the illuminator above the examined object.

It is recommended that the pair of mirrors is placed at the same height, at a predetermined distance from each other, preferably - symmetrically about a plane containing the symmetry axis of the object.

It is favourable for the mirrors to have the same geometry of the reflective surfaces.

Advantageously, the distance between the mirrors and the width of the opening in the casing correspond to the dimensions of the container and acknowledge inaccuracies in positioning of both - the container and the examined object.

In a preferred embodiment, the examined object is illuminated by the illuminator, wherein its upper surface is illuminated directly and the lateral and bottom surfaces are illuminated through the pair of mirrors.

The rays reflected off the surface of the object are recorded by the lens-type camera, and it is best to record the image of the upper surface directly and to record the images of the lateral and bottom surfaces at the full circumferential range of 360° with the use of optical rays reflected off the mirrors.

By using the proposed solution, it is also possible to record images only from the lateral or bottom surfaces of the object. When recording only the image from the lateral surface, it is not required that the bottom edge of the mirror is situated below the examined object.

It is favourable to put an optical filter, which may be a neutral-density filter or a polarizing filter, between the lens and the examined object, which wi!! decrease the intensity of the image of the upper surface of the object.

It is recommended that the light-reflecting surfaces of the mirrors are segments of a truncated cone cut by a plane parallel to the axis of the cone and distant from the axis of the cone, whereas the mirrors should be placed symmetrically about a plane containing the optical axis of the lens and the light-reflecting surfaces should be oriented towards the examined object. It is advantageous if in a particular embodiment of the invention, wherein the surface of the mirrors has a geometry based on a segment of a cone, the imaging angle (2a) of the object circumference in a cross- section perpendicular to the optical axis of the lens is:

where: r - radius of the cap, r' - radius of the arc, Ob - center of the object 2, intersection of the optical axis of the camera 6 with the plane πρ, Om - center of the circle, with the arc L being its segment, x - distance between Ob and Om, 2β - angle between the rays reflected from the edges of the arc, 2a - imaging angle of the object 2 circumference.

Preferably, the light-reflecting surfaces of the mirrors are segments of a truncated cone of an angle adjusted to the object to be inspected. The cone apex angle between the light-reflecting surfaces may, in particular, be 120°.

The light-reflecting surfaces of each mirror can also be a set of at least two interconnected segments of truncated cones of different inclination angles.

Moreover, the light-reflecting surfaces can also be segments of the rotationally symmetrical surfaces such as sphere, elliptical cone or ellipsoid. Due to technological reasons, it is most preferred when the mirrors 3.1 and 3.2 have the same geometry of the reflective surface and are located symmetrically about the container. However, it is possible to use mirrors of a different geometry of mirror surface, e.g. a segment of a cone (in the mirror 3.1) and a segment of a sphere (in the mirror 3.2).

The system according to the invention is adapted for inspecting objects as they move on continuous motion production lines - due to an appropriate position near the examined objects. The system of the pair of mirrors placed opposite to each other at a suitable distance arranged in such a way that their bottom edge is below the examined object freely moving between them, allows for simultaneous observation of its bottom, upper and lateral surfaces. Placing the mirrors close to the examined object creates the conditions for obtaining a clear and accurate image of the object on the camera.

The system is ergonomic as it allows for full circumferential control of the containers' closures with the use of a single camera, and due to the fact that the pair of mirrors is used both for illuminating and recording the image of the lateral and bottom surfaces of the examined object, the need to use additional systems such as more cameras, mirrors, additional illuminators, etc., is reduced. What is more, by ensuring free movement of the examined object between the mirrors, it is not required to use additional propulsion system components. The invention will be described in detail on the basis of its exemplary embodiments, with reference to the attached drawings presenting:

Fig. 1 a schematic diagram: exemplary arrangement of the mirrors in relation to the examined container positioned on the production line,

Fig. 2 a top view of the system with the direction of the container's movement marked,

Fig. 3 a cross-sectional projection of the system in πζ_1 plane from Fig. 2,

Fig. 4 the path of the rays coming out of the entrance pupil of the lens after being reflected off the mirrors in a cross-section perpendicular to the optical axis of the lens,

Fig. 5 the path of the rays coming out of the entrance pupil of the lens after being reflected off the mirrors in a cross-section containing the optical axis of the lens,

Fig. 6 an exemplary embodiment of the mirrors, in which the mirror surfaces are segments of a cone,

Fig. 7 an exemplary embodiment of the invention using the mirrors whose reflecting surfaces are segments of a sphere,

Fig. 8 an image recorded by the camera,

Fig. 9 a cross-sectional projection of the system in πζ_1 plane shown in Fig. 2, with only the path of the optical rays passing through the optical filter shown,

Fig. 10 a neutral-density filter,

Fig. 11 a cross-sectional projection of the system in ττζ_1 plane from Fig. 2, with the path of optical rays marked,

Fig. 12 a detailed view of part A of the system shown in Fig. 3, marked in Fig. 11,

Fig. 13 a cross-sectional projection of the system in πζ_2 plane from Fig, 2, with the path of optical rays shown,

Fig. 14 a detailed view of part B of the system, marked in Fig. 13 with the exposed path of the rays coming out of the entrance pupil shown in Fig. 5,

Fig. 15 a schematic imaging of the object by a mirror, in a plane perpendicular to the optical axis of the camera iens, with the projection of optical rays path marked.

As shown in Fig. 1, Fig. 2 and Fig. 3, the system in accordance with the invention consists of a digital camera 7 with a lens 6, an illuminator 5 and a pair of mirrors 3.1 and 3.2. The illuminator 5 and the pair of mirrors 3.1 and 3.2 are mounted in a casing 4. The examined object 2 is closure of a container 1 , which - as shown in Fig. 1 - is continuously transported on a conveyor (devices of this type are known and do not require further explanation). The distance between the mirrors 3.1 and 3.2, and the opening in the casing 4 are designed to allow free movement of the container 1. The examined object 2 is iiiuminated by the iliuminator 5. As shown in Fig. 3, its upper surface 2.1 is illuminated directly, whereas its lateral surface 2.2 and bottom surface 2.3 are illuminated with the use of the pair of mirrors 3.1 and 3.2. Camera 7 with lens 6 records rays reflected from the surface of the object, wherein the image of the upper surface 2.1 is recorded by the camera 7 directly and images of the lateral surface 2.2 and bottom surface 2.3 (at a full range of 360^°) are recorded by the use of optical rays reflected off the mirrors 3.1 and 3.2. in order to describe the representation of the geometry of the reflecting surfaces of the mirrors 3.1 and 3.2, two cross-sections may be used. As shown in Fig. 4, in the cross-section of the reflecting surface perpendicular to the optical axis of the lens, two curves L.1 and L.2 are formed reflecting the rays coming out of the entrance pupil of the lens 6. The imaging system according to the invention is characterized in that the pencil of rays of the angle (2γ) smaller than 180^°, formed by the rays coming out of the entrance pupil of the lens, after being reflected off the curve L (L.1 or L.2), comprises the examined lateral surface of the object at the imaging angle (2a) greater than 180°. Since in this plane two curves being arcs L.1 and L.2 are put opposite to each other, imaging of the lateral and bottom surfaces of the object is achieved at the full range of 360^°. Apart from that, in the cross-section of the reflecting surface containing the optical axis, as shown in Fig. 5, two curves K.1 and K.2 are formed, reflecting also the rays coming out of the entrance pupil of the lens 6. The imaging system implemented in the system according to the invention is characterized in that the pencil of rays reflected off these curves K.1 and K.2 includes the examined profiles of both the lateral surface 2.2 and bottom surface 2.3 and/or their segment. Reflecting surfaces may be, e.g., segments of a cone as shown in Fig. 6, or segments of a sphere as shown in Fig, 7, or segments of an elliptical cone or ellipsoid. It is recommended - for technological reasons - that mirrors 3,1 and 3.2 have the same geometry of the reflective surface and are placed symmetrically about a plane containing the optical axis of the lens. It is obvious to the specialist that using mirrors of different geometry, such as a segment of a cone in mirror 3.1 and a segment of a sphere in mirror 3.2, is also feasible.

In the system according to the invention, the effect of irregular distribution of intensity in the image from camera 7 is observed in the regions corresponding to different parts of the surface of the observed object 2. This is due to the fact that, as shown in Fig. 8, for recording image 2.1' of the upper surface 2.1 of the object 2, the light being reflected directly off this surface is used, and for recording images 2.2^! and 2.3' of the lateral surface 2.2 and bottom surface 2.3 of the object 2, the light reflected off mirrors 3.1 and 3.2 is used. At the image recorded by camera 7, in the image of the upper surface 2.1 ^s of the object 2, high intensity will be observed compared to the images of the lateral surface 2.2' and bottom surface 2.3' of the object 2, which adversely affects the analysis of the recorded image. That is why it is favourable to use in the system according to the invention an optical filter 8 reducing the intensity of the image of the upper surface 2.1 ' of the object 2. This will equalize the intensity of the imaging of all the surfaces of the object 2 in images 2.1 ', 2.2^! and 2.3' recorded by the camera 7. Fig. 9 presents an exemplary embodiment of the system according to the invention, where an optical filter 8 was placed between the lens 6 and the examined object 2. This filter eliminates overexposures in the images recorded by camera 7 representing the upper surface 2.1 of the object 2. The optical filter 8 may be a neutral-density filter (neutral filter with an adjusted range of the transmission value) as shown in Fig. 10. A neutral-density filter 8 has the shape of a filtering surface 9 which, located in a filter 8 plane, diminishes the intensity of only the rays imaging the upper surface 2.1 of the object 2. A polarizing filter may also be applied for observing the object 2 of non- metal upper surface 2.1.

Below follows a description of the exemplary system according to the invention, adapted for inspecting the surface of the object 2 in the form of a cap being a closure of a vial, moving linearly on a conveyor of a production line, as it is schematically shown in Fig. 1.

The optical axis of the lens 6 of the camera 7 was coaxial with the symmetry axis of the controlled cap 2 of 18-mm external diameter, 2-mm width of the bottom crimp connection (the bottom surface of the cap) and 6-mm height. The examined cap 2 has been illuminated by the illuminator 5. Camera 7 directly recorded the image of the upper surface 2.1 of the cap 2, and with utilization of the mirrors 3.1 and 3.2 recorded a full circumferential view (of 360° range) of the lateral surface 2.2 and bottom surface 2.3 (crimp connection) of the cap 2. Mirrors 3.1 and 3.2 had the same geometry. Light-reflecting surfaces of the mirrors 3.1 and 3.2 were segments of a truncated cone of an inclination angle of 120°, a radius of the top base equal to 35.5 mm and a radius of the bottom base of 24 mm, cut by a plane parallel to the axis of the cone located 14 mm away from it. Mirrors 3.1 and 3.2 were located symmetrically about a plane containing the optical axis of the lens, the light-reflecting surface was oriented towards the examined cap 2. The distance between the optical axis of the lens 6 and the axis of the truncated cone whose segment was the reflecting surface of the mirror 3.1 was 4 mm. Similarly, the distance between the optical axis of the lens 6 and the axis of the truncated cone whose segment was the reflecting surface of the mirror 3.2 was also 4 mm. The distance between the mirrors 3.1 and 3.2 was 20 mm. The bottom edges of the mirrors 3.1 and 3,2 were located 16 mm below the bottom edge of the cap 2. Such shape and position of the mirrors 3.1 and 3.2 allowed for full imaging (at a range of 360°) of the lateral surface 2.2 and bottom surface 2.3 of the cap 2, at the same time enabling free movement of the vial 1 (with a diameter of 18 mm) with the cap 2 between the mirrors 3.1 and 3.2.

The ability to implement and the advantages resulting from full imaging of the surface of the cap with the use of the system according to the invention during its exploitation are confirmed by the following exemplary embodiment of the invention with reference to the formulas describing determination of the angle of the circumference view of the cap, taking into consideration the angle between the rays reflected off the edge of the arc L formed as a result of intersection of a plane perpendicular to the optical axis with the surface reflecting light off the mirror 3.1.

As described above, in any plane perpendicular (πρ) to the optica! axis of the lens 6 of the camera 7 intersecting the reflecting surface of the mirror 3.1 , the optical rays between the cap 2 and the entrance pupil of the lens 6 were reflected off the arc L, as shown in Fig. 15, referring to the following parameters of the optical system included in the formulas determining the imaging angle 2a.

Imaging angle 2a of the circumference of the cap 2, obtained with the use of the arc L, is specified by the following formulas:

where:

r - radius of the cap,

r' - radius of the arc,

Ob - center of the cap, intersection of the optical axis of the lens 6 of the camera 7 with plane πρ,

Om - center of the circle, with the arc L being its segment,

x - distance between Ob and Om,

d - distance between the edges of the arc and Ob,

2β - angle between the rays reflected off the edge of the arc,

2a - imaging angle of the cap 2 circumference.

In order to determine the above formulas, a formula was used describing reflection of light off a spherical surface. The obtained values are therefore approximate and the error is affected by, inter alia, spherical aberration.

In the calculations, two extreme cases of the cap 2 imaging have been taken into account:

(i) first: the lateral surface with a diameter of 18 mm, imaged by an arc having a radius of 35.5 mm. For this case, the imaging angle 2a is 242°; fji) second: the bottom surface of the minimal diameter of 14 mm, imaged by an arc having a radius of 24 mm. Radii of the arcs 35.5 mm and 24 mm are determined by the upper and bottom edges of the mirror 3.1. The imaging angle 2a in this case is 260°.

Imaging angles for the mirror 3.2 were in this embodiment the same and because the mirrors 3.1 and 3.2 are located symmetrically opposite to each other, the lateral surface 2.2 and bottom surface 2.3 of the cap 2 were imaged at the full angular range. Moreover, a part of the lateral surface 2.2 and bottom surface 2.3 of the cap 2 was imaged with both mirrors - 3.1 and 3.2; these were overlaps, thanks to which the system of quality control based on the system according to the invention proved to be resistant to inaccuracies of positioning of the vial 1.

The optical rays between the cap 2 and the entrance pupil of the lens 6 were reflected as well in planes πζ containing the optical axis of the lens 6. The optical rays in the planes πζ were reflected off the surface of the mirror according to geometrical optics Saws: light incident on the mirror surface was reflected, while the incident ray, normal to the reflecting surface and reflected ray were in one plane and the angle of incidence was equal to the angle of reflection. In the exemplary imaging system a lens with a focal length of 25 mm was used, the distance between the entrance pupil of the iens 6 and the upper surface of the cap was 305 mm. The distance between the bottom edges of the mirrors 3.1 and 3.2 and the upper surface of the cap 2 was 22 mm. Two extreme cases of the imaging of the cap 2 were taken into consideration:

(i) first, wherein the imaging surface of the cap 2 was nearest to the mirrors 3.1 and 3.2 - plane πζ_1 passing through the center of the arc L,

(ii) second, wherein the imaging surface of the cap 2 was furthest from the mirrors 3.1 and 3.2 - plane πζ_2 passing through one edge of the arc L (bottom edge of the mirrors 3.1 and 3.2 was taken into consideration).

Projection of the rays reflected at the edges formed by intersection of the planes πζ_1 and πζ_2 with the mirror 3 is shown in Fig. 11 (on Fig. 12, the part A is enlarged with a more detailed description of the path of the rays that are directed towards the lateral and bottom surfaces of the cap) and Fig. 13 {on Fig. 14, the part B is enlarged with a more detailed description of the path of the rays that are directed towards the lateral and bottom surfaces of the cap), respectively. Mirrors 3.1 and 3.2 in both cases of imaging of the cap 2 provided imaging of the lateral surface 2.2 and the bottom surface 2.3.

The image shown in Fig. 8 recorded by the camera 7 directly represents the obtained image of the upper surface 2.1' of the cap 2, and the image of the mirrors 3.1' and 3.2' reveals the imaging of the lateral surface 2.2' and bottom surface 2.3' of the cap 2. In the image recorded directly, the area of the upper surface 2.1' of the cap 2 had significantly higher intensity than the areas of the lateral surface 2.2' and bottom surface 2.3' of the cap 2. In order to equalize the intensity in the recorded images, a neutral-density filter was applied with a transmission coefficient of 30%. This filter was located at a distance of 31 mm from the entrance pupil of the lens 6. In the filter plane, the pencil of rays imaging the upper surface 2.1 of the cap 2 covered an area of a diameter of 2 mm. Neutral-density filter 8 had the shape of a circle 9 of a diameter of 4 mm, which equalized the intensity in the recorded areas, and thus positioning errors of the container 1 and the examined object 2 did not have an unfavourable impact on the recorded image.

List of references

1 - container

2 - object

2.1 - upper surface of the object

2.2 - lateral surface of the object

2.3 - bottom surface of the object

2.1 ' - image of the upper surface of the object recorded by camera 7

2.2' - image of the lateral surface of the object recorded by camera 7

2.3' - image of the bottom surface of the object recorded by camera 7

3.1 - mirror 1

3.2 - mirror 2

3.1' - image of mirror 3.1 recorded by camera 7

3.2' - image of mirror 3.2 recorded by camera 7

4 - casing

5 - illuminator

6 - lens of camera 7

7 - camera

8 - optical filter

9 - filtering surface of a neutral-density filter

r - radius of the cap

r' - radius of the arc

Ob - center of the cap, intersection of the optical axis of lens 6 of camera 7 with plane πρ

Om - center of the circle, with the arc L being its segment

x - distance between Ob and Om d - distance between the edges of the arc L and Ob

2β - angle between the rays reflected from the edge of the arc

2a - imaging angle of the cap 2 circumference

L.1 and L.2 - curves formed in the cross-section of the mirror surface perpendicular to the optical axis of the lens

K.1 and K.2 - curves formed in the cross-section of the mirror surface containing the optical axis of the lens

Claims

Patent claims

1. A system for control of the external surfaces and geometry of objects manufactured on production lines, utilizing peripheral observation at full 360" angular range, in particular for automatic quality control of the examined element such as a cap closing a container, consisting of a digital camera with a lens, a single illuminator, mirrors and a casing, characterized in that in the casing (4) containing the illuminator (5), a pair of mirrors (3.1 and 3.2) is put in such a way that their bottom edge is below the examined object (2) which through an opening in the casing (4), moves freely between those mirrors together with the container when being transported on a conveyor on a production line and the rays reflected off the mirrors (3.1 and 3.2) enable imaging of the lateral and bottom surfaces of the entire object at the full range.

2. The system according to claim 1 , characterized in that two pencils of rays coming out of the entrance pupil of the lens (6), each of an angle smaller than 180^°, after being reflected off the mirrors (3.1 and 3.2), form the image of the examined object (2) at the full angular range of 360^° in a cross-section perpendicular to the optical axis of the lens (6).

3. The system according to claim 1, characterized in that two pencils of rays coming out of the entrance pupil of the lens (6), after being reflected off the mirrors (3.1 and 3.2), image the profile of the lateral surface (2.2) and bottom surface (2.3) or its segment in a cross-section containing the optical axis of the lens (6).

4. The system according to claim 1 , characterized in that the illuminator (5) is positioned above the examined object (2), illuminating it from above.

5. The system according to claim 1 , characterized in that a pair of mirrors (3.1 and 3.2) is arranged symmetrically about a plane containing the optical axis of the lens at the same height at a predetermined distance from each other.

6. The system according to claim 1 , characterized in that the distance between the mirrors (3.1 and 3.2) and the width of the opening in the casing (4) correspond to the dimensions of the container

(1) and allow for inaccuracies in the positioning of both - the container (1) and the examined object

(2) .

7. The system according to claim 1 , characterized in that the examined object (2) is illuminated by the illuminator (5), wherein its upper surface (2.1) is illuminated directly and its lateral surface (2.2) and bottom surface (2.3) are illuminated with the use of the pair of mirrors (3.1 and 3.2).

8. The system according to claim 1 , characterized in that the rays reflected off the surface of the object (2) are recorded by the camera (7) with the lens (6), wherein the image of the upper surface (2.1) is recorded directly and the images of the lateral surface (2.2) and bottom surface (2.3) are recorded at the full range of 360° with the use of optical rays reflected off the mirrors (3.1 and 3.2).

9. The system according to claim 1, characterized in that only the image of the lateral surface (2,2) is imaged and recorded. In this case, it is not required that the bottom edge of the mirror is situated below the examined object.

10. The system according to claim 1 , characterized in that an optical filter (8) is put between the lens (6) and the examined object (2), reducing the intensity of the image of the upper surface (2.1') of the object (2).

11. The system according to claim 10, characterized in that the optical filter (8) is a neutral-density filter.

12. The system according to claim 10, characterized in that the optical filter (8) is a polarizing filter.

13. The system according to claim 1 , characterized in that for the surface of the mirrors (3.1 and 3.2) with geometry based on a segment of a cone, the imaging angle (2a) of the object 2 circumference in a cross-section perpendicular to the optical axis of the lens is described by the following equation:

2a = 2,β -r 2.X sin i— ;— r i- x J I

where: r - radius of the cap, r' - radius of the arc, Ob - center of the object 2, intersection of the optical axis of the camera 7 with the plane πρ, Om - center of the circle, with the arc L being its segment, x - distance between Ob and Om, 2β - angle between the rays reflected off the edge of the arc, 2a - imaging angle of the object 2 circumference.

14. The system according to claim 1 , characterized in that the mirrors (3.1 and 3.2) have the same geometry of the reflective surfaces.

15. The system according to claim 1 , characterized in that the Iight-reflecting surfaces of the mirrors (3.1 and 3.2) are segments of a truncated cone cut by a plane parallel to the axis of the cone distant from the axis of the cone, while the mirrors (3.1 and 3.2) are put symmetrically about a plane containing the optical axis of the lens and the light reflecting surface is directed towards the examined object (2).

16. The system according to claim 1, characterized in that the light-reflecting surfaces of the mirrors (3.1 and 3.2) are segments of a truncated cone of an angle adjusted to the object (2).

17. The system according to claim 16, characterized in that the angle of the Iight-reflecting surfaces of the mirrors (3.1 and 3.2) is 120°.

18. The system according to claim 1 , characterized in that the light-reflecting surfaces of each of the mirrors (3.1 and 3.2) are each a set of at least two interconnected segments of truncated cones of different inclination angles.

19. The system according to claim 1, characterized in that the light-reflecting surfaces of each of the mirrors (3.1 and 3.2) are segments of rotationally symmetrical surfaces such as sphere, elliptical cone or ellipsoid.