APPARATUS AND METHOD FOR ACQUIRING DATA RELATIVE TO A DIMENSION OF AN ELONGATED OBJECT

Abstract

The present invention relates to an apparatus for acquiring data relative to a dimension of an elongated object defining a longitudinal axis and a first and a second end, the apparatus comprising: an imaging sensor device defining a field of view and an optical axis, the imaging sensor device being adapted to image the elongated object in the field of view; a transporting device adapted to position the elongated object in the field of view and to transport the elongated object in a transport direction substantially parallel to the longitudinal axis of the elongated object and forming an angle with the optical axis; an illuminating device adapted to emit electromagnetic radiation to illuminate the elongated object in the field of view; and an optical deflection system including an optical deflector which is adapted to be movable between a first operative position where it is located outside the field of view of the imaging sensor device and a second operative position where it is located within the field of view of the imaging sensor device, and which is adapted to deflect electromagnetic radiation travelling parallel to the longitudinal axis towards said imaging sensor device so as to obtain an image of the first or of the second end of the elongated object. The present invention also relates to a method for acquiring data relative to a dimension of an elongated object defining a longitudinal axis and having a first and a second end.

Claims

1-20. (canceled)

21. Apparatus for acquiring data relative to a dimension of an elongated object defining a longitudinal axis and a first and a second end, the apparatus comprising: an imaging sensor device defining a field of view and an optical axis, the imaging sensor device being adapted to image the elongated object in the field of view; a transporting device adapted to position the elongated object in the field of view and to transport the elongated object in a transport direction substantially parallel to the longitudinal axis of the elongated object and forming an angle with the optical axis; an illuminating device adapted to emit electromagnetic radiation to illuminate the elongated object in the field of view; and an optical deflection system including an optical deflector which is adapted to be movable between a first operative position and a second operative position and which is adapted, in the second operative position, to deflect electromagnetic radiation travelling parallel to the longitudinal axis towards said imaging sensor device so as to obtain an image of the first or of the second end of the elongated object; wherein the optical deflection system includes an optical deflector holder adapted to rotate the optical deflector so that the second operative position comprises a first sub-position in which electromagnetic radiation travelling parallel to the longitudinal axis in a first versus is deflected towards said imaging sensor device so as to obtain an image of the first end of the elongated object and a second sub-position in which electromagnetic radiation travelling parallel to the longitudinal axis in a second versus is deflected towards said imaging sensor device so as to obtain an image of the second end of the elongated object.

22. Apparatus according to claim 21, wherein said optical detector includes a prism adapted to be positioned in front of an end of the elongated object and having a facet angled with respect to the transport direction.

23. Apparatus according to claim 22, wherein an angle formed between the transport direction and the facet of the prism is comprised between about 30 and about 60.

24. Apparatus according to claim 23, wherein the angle formed between the transport direction and the facet of the prism is of about 45.

25. Apparatus according to claim 21, wherein the transport direction is substantially perpendicular to the optical axis.

26. Apparatus according to claim 25, wherein the imaging sensor device includes a fixed focus camera and said transporting device is adapted to transport said elongated object along the transport direction lying in a fixed focus plane of said imaging sensor device.

27. Apparatus according to claim 21, wherein the transporting device is adapted to rotate the elongated object around the longitudinal axis.

28. Apparatus according to claim 21, wherein in said second operative position the optical deflector is located at a geometrical intersection between the transport direction and the optical axis.

29. Apparatus according to claim 21, wherein the image sensor device includes an image sensor holder and an image sensor, the image sensor holder being adapted to translate the image sensor along the optical axis.

30. Apparatus according to claim 21, wherein the illuminating device comprises one or more of the following: a back light positioned along the optical axis on an opposite side of the transport direction with respect to the imaging sensor device, the back light being adapted to irradiate a surface of the elongated object facing the back light; a front light positioned along the optical axis on a same side of the transport direction with respect to the imaging sensor device, the front light being adapted to irradiate a surface of the elongated object facing the imaging sensor device.

31. Apparatus according to claim 21, comprising: an elaborating unit, adapted to compute a value of a dimension of the elongated object from the image acquired by the imaging sensor device.

32. A method for acquiring data relative to a dimension of an elongated object defining a longitudinal axis and having a first and a second end, the method comprising the step of: providing an imaging sensor device having an optical axis and a field of view; moving the elongated object along a transport direction parallel to the longitudinal axis and forming an angle with the optical axis in the field of view of the imaging sensor device; irradiating the elongated object by means of electromagnetic radiation; and deflecting electromagnetic radiation travelling parallel to the longitudinal axis towards said imaging sensor device so as to form an image of one of the ends of the elongated object; wherein the step of deflecting electromagnetic radiation comprises at least one of the following: deflecting electromagnetic radiation travelling parallel to the longitudinal axis towards said imaging sensor device by means of an optical deflection system positioned in front of the first end of the elongated object so as to form an image of the first end of the elongated object; deflecting electromagnetic radiation travelling parallel to the longitudinal axis towards said imaging sensor device by means of the optical deflection system positioned in front of the second end of the elongated object axially opposite to the first end so as to form an image of the second end of the elongated object.

33. Method according to claim 32, wherein between the step of: deflecting electromagnetic radiation travelling parallel to the longitudinal axis towards said imaging sensor device by means of the optical deflection system positioned in front of the first end of the elongated object so as to form an image of the first end of the elongated object; and the step of: deflecting electromagnetic radiation travelling parallel to the longitudinal axis towards said imaging sensor device by means of the optical deflection system positioned in front of the second end of the elongated object axially opposite to the first end so as to form an image of the second end of the elongated object; the method includes the step of: rotating the optical deflection system.

34. Method according to claim 32, wherein between the step of: deflecting electromagnetic radiation travelling parallel to the longitudinal axis towards said imaging sensor device by means of the optical deflection system positioned in front of the first end of the elongated object so as to form an image of the first end of the elongated object; and the step of: deflecting electromagnetic radiation travelling parallel to the longitudinal axis towards said imaging sensor device by means of the optical deflection system positioned in front of the second end of the elongated object axially opposite to the first end so as to form an image of the second end of the elongated object; the method includes the step of: moving the elongated object along the transport direction.

35. Method according to claim 32, comprising: obtaining an image of a side surface of the elongated object, said side surface being substantially parallel to the longitudinal axis of the elongated object.

36. Method according to claim 32, including: obtaining an image of a first side surface of the elongated object; rotating the elongated object along the longitudinal axis; and obtaining an image of a second side surface of the elongated object rotated with respect to the first side surface.

37. Method according to claim 32, comprising: determining a dimension of said elongated object from the image.

38. Method according to claim 32 using the apparatus for acquiring data relative to a dimension of an elongated object defining a longitudinal axis and a first and a second end, the apparatus comprising: an imaging sensor device defining a field of view and an optical axis, the imaging sensor device being adapted to image the elongated object in the field of view; a transporting device adapted to position the elongated object in the field of view and to transport the elongated object in a transport direction substantially parallel to the longitudinal axis of the elongated object and forming an angle with the optical axis; an illuminating device adapted to emit electromagnetic radiation to illuminate the elongated object in the field of view; and an optical deflection system including an optical deflector which is adapted to be movable between a first operative position and a second operative position and which is adapted, in the second operative position, to deflect electromagnetic radiation travelling parallel to the longitudinal axis towards said imaging sensor device so as to obtain an image of the first or of the second end of the elongated object; wherein the optical deflection system includes an optical deflector holder adapted to rotate the optical deflector so that the second operative position comprises a first sub-position in which electromagnetic radiation travelling parallel to the longitudinal axis in a first versus is deflected towards said imaging sensor device so as to obtain an image of the first end of the elongated object and a second sub-position in which electromagnetic radiation travelling parallel to the longitudinal axis in a second versus is deflected towards said imaging sensor device so as to obtain an image of the second end of the elongated object.

Description

[0055] Further advantages of the invention will become apparent from the detailed description thereof with no-limiting reference to the appended drawings:

[0056] FIGS. 1-3 are schematic perspective views of an apparatus for acquiring data relative to a dimension of an elongated object according to the present invention, in three different operative configurations.

[0057] With reference to the figures, an apparatus for acquiring data relative to a dimension of an elongated object according to the present invention is globally indicated with reference number 100.

[0058] The elongated object 10 defines a longitudinal axis 12 and a first and a second end 14, 16.

[0059] The apparatus 100 comprises an imaging sensor device 20, a transporting device 30, an illuminating device 40 and an optical deflection system 50.

[0060] The imaging sensor device 20 defines a field of view 22 and an optical axis 24. The elongated object 10 is located in the field of view 22, so that the imaging sensor device 20 images the elongated object 10. Further, the imaging sensor device 20 may define a focus plane, that is a plane the object lying in which are focussed in the imaging sensor device.

[0061] The transporting device 30 is associated to the elongated object 10 (for the sake of simplicity in the figures, the transporting device 30 is shown only in FIGS. 1, 2). The transporting device 30 positions the elongated object 10 in the field of view 22 and transports the elongated object 10 in a transport direction 32 substantially parallel to the longitudinal axis 12 of the elongated object 10. The transport direction 32 forms an angle with the optical axis 24.

[0062] Preferably, the transport direction 32 is substantially perpendicular to the optical axis 32 (see FIGS. 1-3), the transport direction 32 being depicted as an arrow in FIG. 2.

[0063] Preferably, the transporting device 30 can also rotate the elongated object 10 around the longitudinal axis 12.

[0064] The image sensor device 20 includes an image sensor 26 and an image sensor holder 28 (for the sake of simplicity in the figures, the image sensor holder 28 is shown only in FIG. 1). The image sensor holder 28 translates the image sensor 26 along the optical axis 24.

[0065] The image sensor 26 can be a fixed focus camera and preferably the transporting device 30 transports the elongated object 10 along the transport direction 32 lying in a fixed focus plane of the imaging sensor device 20.

[0066] The illuminating device 40 emits electromagnetic radiation to illuminate the elongated object 10 in the field of view 22, as shown in FIG. 1 (for the sake of simplicity in the figures, the illuminating device 40 is shown only in FIG. 1).

[0067] As shown in the non-limiting example of FIG. 1, the illuminating device 40 comprises a back light 42 positioned along the optical axis 24 on an opposite side as the imaging sensor device 20 with respect to the transport direction. The back light 42 irradiates a surface 18 of the elongated object 10 facing the back light 42.

[0068] Alternatively or in addition, the illuminating device 40 comprises a front light (not shown in the figures) positioned along the optical axis 24 on a same side as imaging sensor device 20 with respect to the transport direction. The front light irradiates a surface of the elongated object 10 facing the imaging sensor device 20.

[0069] The optical deflection system 50 includes an optical deflector 52 and an optical deflector holder 54.

[0070] The optical deflector 52 is movable between a first operative position where it is located outside the field of view 22 of the imaging sensor device 20 (see FIG. 1) and a second operative position where it is located within the field of view 22 of the imaging sensor device 20 (see FIGS. 2, 3). The optical deflector 52 deflects electromagnetic radiation travelling parallel to the longitudinal axis 12 towards the imaging sensor device 20 so as to obtain an image of the first or of the second end 14, 16 of the elongated object 10 (see FIGS. 2 and 3, respectively).

[0071] In the non-limiting example of FIGS. 2 and 3, the optical detector 52 includes a prism which is positioned in front of the two ends 14, 16 of the elongated object 10, respectively. The prism has a facet 53 angled with respect to the transport direction 32.

[0072] Preferably, an angle formed between the transport direction 32 and the facet 53 of the prism is comprised between about 30 and about 60, and more preferably such an angle is of about 45 (see FIGS. 2, 3).

[0073] In the second operative position, the optical deflector 52 is located at a geometrical intersection between the transport direction 32 and the optical axis 24 (see FIG. 2). The optical deflector 52 is positioned along the longitudinal axis 12 of the elongated object 10.

[0074] The optical deflector holder 54 rotates the optical deflector 52 so that the second operative position comprises a first sub-position and a second sub-position, shown in FIGS. 2 and 3, respectively. In the first sub-position, electromagnetic radiation travels parallel to the longitudinal axis 12 in a first versus and is deflected towards the imaging sensor device 20 so as to obtain an image of the first end 14 of the elongated object 10. In the second sub-position, electromagnetic radiation travels parallel to the longitudinal axis 12 in a second versus (substantially opposite to the first versus) and is deflected towards the imaging sensor device 20 so as to obtain an image of the second end 16 of the elongated object 10.

[0075] The apparatus 100 further comprises an elaborating unit (not shown in the figures) which computes a value of a dimension of the elongated object 10 from the image acquired by the imaging sensor device 20.

[0076] The operation of the apparatus 100 is already clear from the above, and it is pointed out below.

[0077] The elongated object 10 is moved along the transport direction 32 parallel to the longitudinal axis 12 and forming an angle preferably of about 90 with the optical axis 24 in the field of view 22 of the imaging sensor device 20. The elongated object 10 is then positioned in a position within the field of view of the imaging sensor device 20.

[0078] The position of the imaging sensor device 20 with respect to the elongated object is then preferably adjusted, for example translating the imagining sensor device 20 along the optical axis of the same, so that the transport direction lies in a focus plane of the imagining sensor device 20. However the following method may be performed using a different apparatus.

[0079] The elongated object 10 is irradiated by means of electromagnetic radiation. Preferably it is irradiated with electromagnetic radiation directed substantially perpendicular to the transport direction.

[0080] Preferably, when the elongated object is within the field of view of the imagining sensor device 20, an image of a side of the elongated object 10 located on the same side as the imaging sensor device 20 with respect to the transport direction is obtained by means of the imaging sensor device 20. Preferably, the elongated object 10 is then rotated along the longitudinal axis 12 of about 180 and an image of an opposite side of the elongated object, now also facing the imaging sensor device, is taken.

[0081] Preferably, before the elongated object 10 is positioned in front to the imaging sensor device 20, the optical deflector 52 of the optical deflector system is positioned from a first operative position away from the field of view of the imaging sensor device 20 depicted in FIG. 1 to a second operative position where it is at an intersection between the optical axis and the transport direction, as depicted in FIG. 2. The electromagnetic radiation travelling parallel to the longitudinal axis 12 is deflected towards the imaging sensor device 20, so that an image of one of the ends 14, 16 of the elongated object 10, preferably first end 14, can be formed by the imaging sensor device 20.

[0082] In particular, the electromagnetic radiation travelling parallel to the longitudinal axis 12 is deflected by means of the optical deflection system 50 when it is positioned in front of the first end 14 of the elongated object 10 so as to form an image of the first end 14 of the elongated object 10. In this first configuration, the optical deflector holder 54 rotates the optical deflector 52 in the above-mentioned first sub-position of the second operative position (see FIG. 2).

[0083] Preferably, after an image of an end of the elongated object 10 has been taken, the optical deflection system 50 returns in the first operative position. The elongated object 10 is then moved along the transport direction. When the elongated object has been moved within the field of view of the imaging sensor device 20 and for example an image of one or two sides of the elongated object has been taken, the optical deflection system is moved back to the second operative position, as depicted in FIG. 3.

[0084] The electromagnetic radiation travelling parallel to the longitudinal axis 12 is deflected by means of the optical deflection system 50 when it is positioned in front of the second end 16 of the elongated object 10 axially opposite to the first end 14, so that an image of the second end 16 of the elongated object 10 may be formed by the imaging sensor device 20. In this second configuration, the optical deflector holder 54 rotates the optical deflector 52 in the above-mentioned second sub-position of the second operative position (see FIG. 3).

[0085] Therefore, between the above-mentioned first and second sub-positions, the optical deflector 52 of the optical deflection system 50 is rotated, that is the second position includes two sub-positions which differ in the angular position of the optical deflector 52.

[0086] Furthermore, between the above-mentioned first and second sub-positions, the elongated object 10 is moved along the transport direction 32.

[0087] Preferably, the operation of the apparatus 100 comprises obtaining an image of a side surface of the elongated object 10. This side surface is substantially parallel to the longitudinal axis 12 of the elongated object 10.

[0088] More preferably, an image of a first side surface of the elongated object 10 is obtained, then the elongated object 10 is rotated along the longitudinal axis 12, and an image of a second side surface of the elongated object 10 is obtained, which is rotated with respect to the first side surface.