Endoscopic scanning device without mechanical displacement, assembly and associated method

Abstract

Endoscopic scanning device without mechanical displacement, assembly and associated method. The present invention relates to a scanning device (10) for a surface (100) by endoscopy, comprising: - a light source (12) capable of generating an emitted light beam (20) having a wavelength selectively chosen from different wavelengths, - an optical guide (14) adapted to transmit the emitted light beam (20), and - an optical device (16) arranged to receive the light beam emitted and transmitted by the optical guide (14) and to emit an outgoing light beam (30) from the received light beam, the optical device (16) being adapted to emit the outgoing light beam (30) at a location and / or at an angle depending on its wavelength. The invention further relates to an associated scanning assembly and method. Figure for the abstract: Fig 1

Description

Title of the invention: Endoscopic scanning device without mechanical movement, associated assembly and method

[0001] The present invention relates to a device for scanning a surface by endoscopy, and an associated scanning method.

[0002] Such a device is, for example, used for the three-dimensional reconstruction of surfaces that are difficult to access.

[0003] One technique is to use stereoscopy techniques, using two sensors to construct a stereoscopic view.

[0004] However, the integration of two sensors in an endoscopic head, which may be of small size, is complex. Smaller and less precise sensors are, for example, used.

[0005] Such a system with two sensors also limits the field of vision.

[0006] Finally, such a system does not provide sufficient measurement accuracy, particularly if the reconstruction is used for non-destructive surface testing operations.

[0007] Another technique would be to mechanically scan a sensor and a light source.

[0008] However, this is not always possible for locations that are difficult to access.

[0009] The aim of the invention is then to propose a device for scanning a surface making it possible to carry out a three-dimensional reconstruction and capable of being used for surfaces that are difficult to access.

[0010] To this end, the invention relates to a device for scanning a surface by endoscopy, comprising:

[0011] - a light source capable of generating an emitted light beam, the beam emitted light having a wavelength, the wavelength being selectively chosen from different wavelengths, the light source being capable of emitting a light beam of each of the different wavelengths,

[0012] - an optical guide adapted to transmit the emitted light beam, and

[0013] - an optical device arranged to receive the light beam emitted and transmitted by the optical guide and to emit an outgoing light beam from the received light beam, the optical device being adapted to emit the outgoing light beam at a location and / or at an angle depending on its wavelength, the location and / or angle of the outgoing light beam emitted from a received light beam having a first wavelength being different from the location and / or angle of the outgoing light beam emitted from a received light beam having a second wavelength different from the first wavelength.

[0014] The scanning device is thus adapted to perform a scanning of the surface without movement and without requiring a plurality of sensors, by selectively emitting light beams of different wavelengths. Indeed, the light beam emerging from the scanning device physically scans the surface, without movement of the scanning device. It is thus possible to perform a chromatic scanning of the surface.

[0015] According to other advantageous aspects of the invention, the scanning device comprises one or more of the following characteristics, taken individually or in all technically possible combinations:

[0016] - the scanning device comprises an endoscopic head, the optical device being included in the endoscopic head;

[0017] - the outgoing light beam is an outgoing light plane;

[0018] - the outgoing light plane is generated at a location with an emergence angle at the output of the optical device, the location and / or angle of emergence depending on the wavelength of the received light beam;

[0019] - the optical device comprises a diffraction module;

[0020] - the diffraction module comprises a plurality of prisms, more particularly here a pair of prisms, or a diffraction grating,

[0021] - the diffraction module comprises a first prism and a second prism, the first prism comprising a first incident face and a first emerging face, the second prism comprising a second incident face and a second emerging face, the diffraction module being arranged so that the light beam received by the diffraction module is received on the first incident face, emerges from the first prism from the first emerging face, is then received on the second incident face and emerges from the second prism from the second emerging face, the first emerging face and the second incident face being parallel to each other;

[0022] - the light source is capable of generating an emitted light ray, the light ray emitted being the emitted light beam, the optical device comprising a transformation module adapted to generate a light plane from the light beam received by the optical device, the transformation module being arranged upstream of the diffraction module;

[0023] - the optical guide comprises a single optical fiber; and / or

[0024] - the light source is adapted to generate a light beam for a plurality of wavelengths between 400 nm and 750 nm, including at least two wavelengths spaced at least 100 nm apart.

[0025] The invention also relates to an assembly for scanning a surface by endoscopy, comprising a scanning device as described previously and a device for acquiring at least one representation of the surface.

[0026] The invention also relates to a method of scanning a surface by endoscopy, comprising the following steps:

[0027] - provision of a scanning device as previously,

[0028] - provision of a device for acquiring at least one representation of the surface,

[0029] - emission of a first light beam by the light source, the first light beam having a first wavelength, emission of a first light beam exiting from the optical device onto the surface, and acquisition of a first representation of the surface, and

[0030] - emission of a second light beam by the light source, the second light beam having a second wavelength different from the first wavelength, emission of a second light beam exiting through the optical device onto the surface, and acquisition of a second representation of the surface,

[0031] the optical device of the scanning device being fixed relative to the surface between the steps of emitting the first light beam and emitting the second light beam.

[0032] The invention will appear more clearly on reading the description which follows, given solely by way of non-limiting example, and made with reference to the drawings in which:

[0033] [Fig-1] [Fig.l] is a schematic view of an example of a scanning device according to the invention,

[0034] [Fig.2] [Fig.2] is a schematic view of an example of a light source in a scanning device according to the invention,

[0035] [Fig.3] [Fig.3] is a schematic view of an example of use of a scanning device according to the invention, and

[0036] [Fig.4] [Fig.4] is a schematic view of different arrangements of a scanning kit according to the invention in use.

[0037] An example of a device 10 for scanning a surface by endoscopy is shown schematically in [Fig.l].

[0038] Such a device 10 is, for example, used for the three-dimensional reconstruction of surfaces that are difficult to access, in particular in pipes having diameters of less than 10 millimeters, more particularly in nuclear installations or in aeronautical buildings.

[0039] The scanning device 10 comprises a light source 12, an optical guide 14 and an optical device 16.

[0040] More particularly here, the scanning device 10 comprises an endo- head scopic 18, the optical device 16 being included in the endoscopic head 18.

[0041] The optical guide 14 connects the light source 12 to the endoscopic head 18, more particularly to the optical device 16.

[0042] The light source 12 is capable of generating an emitted light beam 20.

[0043] The emitted light beam 20 has a wavelength, the wavelength being selectively chosen from different wavelengths, the light source 12 being capable of generating a light beam of each of the different wavelengths.

[0044] More particularly, the light source is adapted to generate a light beam for a plurality of wavelengths, for example between 400 nm and 750 nm, here including at least two wavelengths spaced at least 100 nm apart.

[0045] The extent of the wavelength range, as well as the spacings between each wavelength, are likely to be different. In particular, they depend in particular on the sensitivity of the sensor (here the acquisition device described below) to certain lengths, and / or on the desired three-dimensional measurement accuracy.

[0046] Here, the light source 12 is capable of generating an emitted light ray, the emitted light ray being the emitted light beam 20.

[0047] The light source 12 comprises, for example, several light-emitting diodes, or a white source provided with chromatic filters.

[0048] Alternatively, the light source comprises prisms or diffractive element systems, or any other optical device for generating a certain number of monochromatic waves. More particularly, as shown in [Fig. 2], the light source 12 comprises, for example, a white light source 50, a diffraction element 52 adapted to diffract the white light generated by the white light source 50, and a system 54 for selecting a light beam of a given wavelength from among the diffracted white light, the selection system 54 being adapted to selectively select a plurality of wavelengths.

[0049] The light source 12 includes an output 56, the selected beam exiting the light source 12 at the output 56.

[0050] The white light source 50 is adapted to generate a light beam of white light.

[0051] The diffraction element 52 comprises, more particularly is, for example, a prism.

[0052] The diffraction element 52 is arranged such that the light beam of white light reaches an incident face of the prism.

[0053] The selection system 54 comprises, for example, a mirror 58 mounted to move in rotation around an axis perpendicular to the plane of the light beams.

[0054] The mirror 58 is arranged so that the beams of diffracted white light are incident on a reflecting surface 60 of the mirror 58.

[0055] Additionally, the mirror 58 is arranged such that, in at least some positions of the mirror about its axis of rotation, a portion of the reflected diffracted light reaches the output 56. The portion of the reflected diffracted light corresponds, for example, to a wavelength interval centered around the so-called selected wavelength. The interval has, for example, an amplitude between 10 nm and 80 nm.

[0056] The light source 12 is capable of generating the light beam emitted at an output of the light source 12.

[0057] The optical guide 14 is adapted to transmit the emitted light beam 20.

[0058] More particularly, the optical guide 14 extends between a first end 22, said first end 22 being connected to the light outlet, and a second end 24.

[0059] The second end is connected to an input of the optical device 16, as will be described below.

[0060] The optical guide 14 comprises, here, a single optical fiber.

[0061] The optical guide then allows access to surfaces that are particularly difficult to access, in particular with a single optical fiber, in particular in pipes with a very small diameter.

[0062] The optical fiber extends from the first end 22 to the second end 24.

[0063] More particularly, the optical guide 14 is made up of a single optical fiber.

[0064] The endoscopic head 18 is, for example, inscribed in a cylinder of diameter, for example example between 6 and 15 millimeters.

[0065] The endoscopic head 18 has, for example, a cylindrical shape.

[0066] The endoscopic head 18 here has a diameter smaller than the aforementioned diameter.

[0067] The endoscopic head 18 comprises the optical device 16.

[0068] The endoscopic head 18 has an inlet 26 and an outlet 28.

[0069] The optical device 16 has an input and an output.

[0070] The input of the optical device 16 corresponds to the input 26 of the endoscopic head 18.

[0071] The output of the optical device 16 corresponds to the output 28 of the endo head scopic 18.

[0072] The optical device 16 is arranged to receive the light beam emitted and transmitted by the optical guide 14 and to emit an outgoing light beam 30 from the received light beam.

[0073] The light beam received by the optical device 16 is identical to the light beam 20 emitted at the output of the light source 12.

[0074] More particularly, the second end 24 of the optical guide 14 is connected to input 26 of optical device 16.

[0075] The light beam received by the optical device 16 is here always received at the same location, with the same angle, independently of the wavelength.

[0076] The optical device 16 is adapted to emit the outgoing light beam 30 at a location and / or at an angle depending on its wavelength, more particularly depending solely on its wavelength, the location and / or angle of the outgoing light beam emitted from a received light beam having a first wavelength being different from the location and / or angle of the outgoing light beam emitted from a received light beam having a second wavelength different from the first wavelength.

[0077] The location and / or angle of the outgoing light beam is always the same for received light beams having the same wavelength.

[0078] This makes it possible to carry out a calibration of the system making it possible to associate the wavelength projected onto the surface with the angle of the beam and the angle of the camera, to analyze the images acquired by the acquisition device, described below.

[0079] Here, the outgoing light beam 30 is an outgoing light plane.

[0080] The outgoing light plane is generated at a location with an emergence angle at the output of the optical device, the location and / or angle of emergence depending on the wavelength of the received light beam.

[0081] More particularly here, the location and / or angle of emergence depends solely on the wavelength.

[0082] The optical device 16 here comprises a diffraction module or diffractor 32.

[0083] The optical device 16 further comprises a transformation module 34.

[0084] The transformation module 34 is here arranged upstream of the diffraction module 32.

[0085] The transformation module 34 is adapted to generate a light plane from the received light beam, that is to say here a light ray.

[0086] The optical path of the light beam is devoid of an optical element between the input 26 and the transformation module 34.

[0087] The light plane generated by the transformation module 34 is independent of the wavelength of the received light beam. In particular, the location and angle of the light plane generated by the transformation module 34 are identical for any wavelength of the received light beam.

[0088] The transformation module 34 comprises, more particularly here, a collimator.

[0089] The collimator is adapted to make the light beam, at the exit of the collimator, as parallel as possible.

[0090] The transformation module 34, here the collimator, comprises only, that is to say it is made up of, a slit.

[0091] The slot has, for example, a depth of between 1 mm and 10 mm, and, for example, a width of between 0.1 mm and 0.3 mm.

[0092] The ratio of the depth of the collimator, i.e. of the slit, to its width is greater than or equal to 10.

[0093] The slot has, for example, in addition, a height of between 5 mm and 10 mm.

[0094] Alternatively, the transformation module 34 comprises, for example, at least one lens.

[0095] The transformation module 34 comprises, for example, a plano-convex cylindrical lens, the convex surface being arranged upstream of the planar surface.

[0096] The received light beam is incident on the convex surface, more particularly perpendicular to the main axis of the lens, and emerges from the flat surface.

[0097] In a particular embodiment, the transformation module 34 comprises a rectangular slot and the cylindrical lens, the rectangular slot being arranged downstream of the cylindrical lens along the optical path.

[0098] The transformation module 34 further comprises, for example, a plano-convex lens upstream of the rectangular slit.

[0099] The diffraction module 32 is adapted to generate the outgoing light beam 30 at a location and / or at an angle depending on its wavelength.

[0100] The diffraction module 32 is here adapted to generate the outgoing light plane from the light plane generated by the transformation module 34.

[0101] The optical path of the light beam is devoid of an optical element between the output of the transformation module 34 and the diffraction module 32.

[0102] The diffraction module 32 comprises one or more prisms, more particularly here a pair of prisms, or a diffraction grating.

[0103] In the example shown, the diffraction module 32 comprises a first prism 36 and a second prism 38.

[0104] The first prism 36 comprises a first incident face 40 and a first emerging face 42.

[0105] The first prism 36 has a first prism angle, the first prism angle being the angle between the first incident face 40 and the first emerging face 42.

[0106] The first incident face 40 and the first emerging face 42 form an angle between them, for example between 60 and 70 degrees.

[0107] The second prism 38 comprises a second incident face 44 and a second emerging face 46.

[0108] The second prism 38 has a second prism angle, here equal to the first prism angle of the first prism 36, the second prism angle being the angle between the second incident face 44 and the second emerging face 46.

[0109] The prism angles are such that the chromatic light plane is projected in the same direction as the light beam at the entrance 26.

[0110] Each prism further comprises a third face forming with the emerging face and the incident face a cylinder with a triangular base. The third faces of the two prisms are, for example, parallel to each other.

[0111] Each prism comprises, for example, dimensions between 4 and 6 millimeters.

[0112] Each prism is, for example, made of glass comprising lead oxide.

[0113] Each prism is, for example, made of SF10 glass.

[0114] The indices of the first prism and the second prism depend on the wavelength. Here they are equal, that is to say that the function of the index of the first prism as a function of the wavelength is identical to the function of the index of the second prism as a function of the wavelength.

[0115] The second prism angle is, for example, here, equal to the first prism angle.

[0116] The diffraction module is arranged so that, along the optical path, the light beam received by the diffraction module, more particularly here corresponding to the light plane generated by the transformation module 34, is received on the first incident face 40, emerges from the first prism 36 of the first emerging face 42, is then received on the second incident face 44 and emerges from the second prism 38 of the second emerging face 46, more particularly for any wavelength of the light beam.

[0117] The first emerging face 42 and the second incident face 44 are, for example here, parallel to each other.

[0118] The first incident face 40 and the second emerging face 46 are, for example, here, parallel to each other.

[0119] The first prism 36 is arranged so that the light beam received by the diffraction module is received on the first incident face 40 forming an angle with the first incident face 40 of between 30 and 60 degrees for example.

[0120] In the example shown, the outgoing light beams of different wavelengths are parallel to each other, for any wavelength. More particularly here, any outgoing light beam is parallel to the incident light beam on the first incident face 40.

[0121] The emergence angle of the outgoing light beam is here equal for all wavelengths.

[0122] Here, the outgoing light plane is parallel to the incident light plane on the first incident face 40, for any wavelength.

[0123] The location of emergence of the outgoing light beam, here the line forming the intersection between the second emergence plane 46 and the outgoing light plane, differs depending on the wavelength.

[0124] Thus, two outgoing light beams, which here form planes, are here parallel to each other, with an offset D.

[0125] Additionally or alternatively, the emergence angle of the outgoing light beam differs depending on the wavelength.

[0126] The emerging light beam from the second emerging face exits the optical device, and here the endoscopic head, at exit 28.

[0127] The optical path of the light beam is devoid of an optical element between the output of the optical device and the output of the endoscopic head.

[0128] A scanning kit and an example of use of the scanning device 10, corresponding to a method of scanning a surface 100 by endoscopy, will now be described with reference to [Fig.3].

[0129] The scanning kit comprises a scanning device 10 as described previously, and an acquisition device 102.

[0130] The acquisition device 102 is, for example, adapted to take at least one image of the surface.

[0131] The acquisition device 102 is sensitive to at least two wavelengths of the light source 12. The acquisition device 102 has an acquisition field 104.

[0132] The acquisition device 102 is, for example, a camera or a photographic device.

[0133] The acquisition device 102 comprises, for example, a CMOS sensor for “complementary metal-oxide-semiconductor” or a CCD sensor for “Charge-Coupled Device” or in French “charge transfer device”.

[0134] The acquisition device 102 and the scanning device 10 are arranged between them, so that the acquisition field 104 comprises all the meeting points 106 between the outgoing light beams 108 and the surface 100, more particularly the light lines.

[0135] The acquisition device 102 is, for example, arranged outside the endoscopic head 18.

[0136] Alternatively, the acquisition device 102 is, for example, arranged in the endoscopic head adjacent to the scanning device 10.

[0137] The scanning kit further comprises, for example, a memory connected to the acquisition device 102 and adapted to store the at least one acquired image of the surface.

[0138] The memory is, for example, arranged in the endoscopic head 18.

[0139] At least one electrical wire then connects, for example, the memory to the acquisition device.

[0140] The scanning kit further comprises here a power supply for the acquisition device.

[0141] The power supply of the acquisition device is, for example, arranged in the endoscopic head 18.

[0142] At least one electrical wire then connects, for example, the power supply to the acquisition device.

[0143] The electrical wire(s) extend, for example, parallel to the optical guide 14 and are connected to the endoscopic head 18.

[0144] The method comprises the following steps:

[0145] - provision of a scanning device 10 as described previously,

[0146] - provision of an acquisition device 102 of at least one representation of the surface,

[0147] - emission of a first light beam by the light source, and

[0148] - emission of a second light beam by the light source.

[0149] The scanning device 10 and the acquisition device 102 are introduced so as to scan the desired area, for example in a pipe with a diameter less than or equal to 20 millimeters.

[0150] The scanning device 10 is arranged so that all of the outgoing light beams for a plurality of, more particularly all of, the wavelengths likely to be emitted by the light source encounter the surface, more particularly in the form of light lines.

[0151] The light lines of the different wavelengths are not confused.

[0152] The light lines of different wavelengths are, for example, parallel between them.

[0153] Different possible arrangements between the acquisition device 102 and the scanning device, more particularly each of the outgoing light beams capable of being generated 110, 112 by the scanning device, are represented in [Fig.4].

[0154] The acquisition device 102 and the scanning device 10 are arranged between them, so that the acquisition field 104 comprises all the meeting points 106 between the outgoing light beams 108 and the surface 100, more particularly the light lines.

[0155] The light source 12 emits the first light beam, here a light ray, according to a first wavelength, for example 532 nm.

[0156] The optical device 16 emits, from the first emitted light beam, a first outgoing light beam towards the surface 100, more particularly here a first outgoing light plane forming a first light line on the surface.

[0157] The acquisition device 102 then acquires a first representation of the surface 100, more particularly a first image of the surface, on which projects the first outgoing light beam, here presenting the first light line.

[0158] The light source 12 emits the second light beam, here a light ray, according to a second wavelength, for example 650 nm.

[0159] The second wavelength is different from the first wavelength, for example by at least 100 nm.

[0160] The optical device 16 emits, from the second emitted light beam, a second outgoing light beam towards the surface, more particularly here a second outgoing light plane forming a second light line on the surface.

[0161] The acquisition device 102 then acquires a second representation of the surface 100, more particularly a second image of the surface, onto which the second outgoing light beam is projected, here presenting the second light line.

[0162] The optical device 16 of the scanning device 10, and furthermore here the acquisition device 102, are fixed relative to the surface 100 between the steps of emitting the first light beam and emitting the second light beam.

[0163] The method advantageously comprises other steps of emitting light beam(s) of wavelengths different from the first and second wavelengths, and of acquiring the corresponding images.

[0164] The emitted wavelengths are selected so as to achieve a continuous scan of the surface 100.

[0165] More particularly, the union of the different light lines generated from all of the light beams emitted during the successive steps corresponds to a continuous section of the surface 100.

[0166] The emission of light beams of different wavelengths, which generate different light lines, thus makes it possible to scan the surface without moving the scanning device.

[0167] Furthermore, the acquisition of several images then makes it possible to reconstruct a three-dimensional representation of the acquired parts of the surface, without requiring a plurality of sensors so as to form a stereoscopic view.

[0168] In an alternative embodiment (not shown), the acquisition device is integrated within the endoscopic head of the scanning device.

Claims

Claims

1. A device (10) for scanning a surface (100) by endoscopy, comprising: - a light source (12) capable of generating an emitted light beam (20), the emitted light beam (20) having a wavelength, the wavelength being selectively chosen from different wavelengths, the light source (12) being capable of emitting a light beam of each of the different wavelengths, - an optical guide (14) adapted to transmit the emitted light beam (20), and - an optical device (16) arranged to receive the light beam emitted and transmitted by the optical guide (14) and to emit an outgoing light beam (30) from the received light beam, the optical device (16) being adapted to emit the outgoing light beam (30) at a location and / or at an angle depending on its wavelength,the location and / or angle of the outgoing light beam (30) emitted from a received light beam having a first wavelength being different from the location and / or angle of the outgoing light beam emitted from a received light beam having a second wavelength different from the first wavelength.,

2. A scanning device according to claim 1, comprising an endoscopic head (18), the optical device (16) being included in the endoscopic head (18).

3. A scanning device according to claim 1 or 2, wherein the outgoing light beam (30) is an outgoing light plane.

4. A scanning device according to claim 3, wherein the outgoing light plane is generated at a location with an emergence angle at the output of the optical device (16), the location and / or the emergence angle depending on the wavelength of the received light beam.

5. A scanning device according to any one of claims 1 to 4, wherein the optical device (16) comprises a diffraction module (32).

6. A scanning device according to claim 5, wherein the diffraction module (32) comprises a plurality of prisms (36, 38), more particularly here a pair of prisms (36, 38), or a dif- fraction.

7. A scanning device according to claim 6, wherein the diffraction module (32) comprises a first prism (36) and a second prism (38), the first prism (36) comprising a first incident face (40) and a first emergent face (42), the second prism (38) comprising a second incident face (44) and a second emergent face (46), the diffraction module (32) being arranged such that the light beam received by the diffraction module (32) is received on the first incident face (40), emerges from the first prism (36) from the first emergent face (42), is then received on the second incident face (44) and emerges from the second prism (38) from the second emergent face (46), the first emergent face (42) and the second incident face (44) being parallel to each other.

8. Scanning device according to any one of claims 5 to 7, wherein the light source (12) is capable of generating an emitted light ray (20), the emitted light ray (20) being the emitted light beam, the optical device (16) comprising a transformation module (34) adapted to generate a light plane from the light beam received by the optical device (16), the transformation module (34) being arranged upstream of the diffraction module (32).

9. A scanning device according to any one of claims 1 to 8, wherein the optical guide (14) comprises a single optical fiber.

10. A scanning device according to any one of claims 1 to 9, wherein the light source (12) is adapted to generate a light beam for a plurality of wavelengths between 400 nm and 750 nm, including at least two wavelengths spaced at least 100 nm apart.

11. Assembly for scanning a surface (100) by endoscopy, comprising a scanning device according to any one of claims 1 to 10 and a device (102) for acquiring at least one representation of the surface.

12. Method for scanning a surface (100) by endoscopy, comprising the following steps: - providing a scanning device (10) according to any one of claims 1 to 10, - providing a device (102) for acquiring at least one representation of the surface, - emitting a first light beam by the light source (12), the first light beam having a first wavelength, emission of a first light beam exiting through the optical device (16) onto the surface (100), and acquisition of a first representation of the surface (100), and - emission of a second light beam by the light source (12), the second light beam having a second wavelength different from the first wavelength, emission of a second light beam exiting through the optical device (16) onto the surface (100), and acquisition of a second representation of the surface (100), the optical device (16) of the scanning device (10) being fixed relative to the surface (100) between the steps of emitting the first light beam and emitting the second light beam.

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