Catoptric imaging device for drill measuring

Abstract

A catoptric imaging device for drill measuring comprising a laser guide, an imaging unit for converting optical image into image information, and processing the image information to obtain a drill measure, a catoptric assembly including a first conical surface, and a second surface including a frustoconical surface, wherein the first surface is arranged relative to the laser guide to reflect a cone beam onto an cross section of the drill to be measured, and wherein the smallest diameter of the frustoconical surface is larger than the largest diameter of the first surface to receive the cone beam reflections and reflect them towards the imaging unit, and wherein the imaging unit is arranged to receive an optical image from the frustoconical surface reflections to obtain a drill measure.

Claims

1. A catoptric imaging device for drill measuring comprising: a laser guide for guiding a laser beam; an imaging unit comprising an imaging element configured to photoelectrically convert an optical image into image information, and an image processor configured to obtain at least one drill measure from the image information; a catoptric assembly comprising a first conical surface, and a second surface arranged below the first conical surface and comprising a frustoconical surface, wherein both surfaces are coaxially aligned with respect to a measuring axis; and wherein the first surface is arranged relative to the laser guide to reflect a cone beam onto an annular cross section of the drill to be measured, wherein a smallest diameter of the frustoconical surface is larger than a largest diameter of the first surface to receive the cone beam reflections and reflect the cone beam reflections towards the imaging unit, wherein the laser guide is disposed between the imaging unit and the catoptric assembly, and wherein the imaging unit is arranged to receive an optical image from the frustoconical surface reflections for generating the drill image information and finally obtaining the at least one drill measure.

2. A catoptric imaging device according to claim 1, wherein the catoptric assembly has a single body formed by an upper part comprising a conical section, and a lower part having a frustoconical configuration.

3. A catoptric imaging device according to claim 2, wherein the upper part further comprises a tubular section below the conical section, and wherein the tubular section is flush with the conical section.

4. A catoptric imaging device according to claim 1, wherein the laser guide comprises an optical fiber for guiding the laser beam, and a probe for enclosing the optical fiber, and wherein the probe longitudinal axis matches the measuring axis.

5. A catoptric imaging device according to claim 4, wherein the first conical surface is fitted at one end of the probe, and wherein the end is made of translucent material for allowing the cone beam to pass.

6. A catoptric imaging device according to claim 4, wherein the laser guide comprises at least one lens at the optical fiber output to collimate the laser beam.

7. A catoptric imaging device according to claim 1, wherein the image processor is configured to calculate diameter of the drill from the drill image information.

8. A catoptric imaging device according to claim 1, wherein the image processor is configured to calculate cylindricity of the drill from the drill image information.

9. A catoptric imaging device according to claim 1, wherein the image processor is configured to calculate ovalization of the drill from the drill image information.

10. A catoptric imaging device according to claim 1, wherein the imaging unit further comprises a display configured to display the drill image information.

11. A catoptric imaging system for drill measuring comprising: the catoptric imaging device according to claim 1; a laser source for providing a laser beam to the laser guide of the catoptric imaging device; and a scanning system adapted to move the catoptric imaging device along the measuring axis.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) For a better comprehension of the disclosure herein, the following drawings are provided for illustrative and non-limiting purposes, wherein:

(2) FIG. 1 shows a longitudinal section view of a catoptric imaging device according to an embodiment of the present disclosure.

(3) FIG. 2 shows a detailed view of the optical paths followed by the laser beam since the laser beam output the laser guide until the drill optical information is directed towards the imaging unit.

(4) FIG. 3 shows the minimum and maximum measurable radius of a drill when using the catoptric imaging device of the disclosure herein.

(5) FIG. 4 shows images of drills with different cross sections. In dash lines, the figure represents the minimum and maximum measurable cross sections.

(6) FIG. 5 shows a detailed view of angular and radial parameters defined by the catoptric assembly configuration and the optical paths followed by the laser beam upon exiting the laser guide.

DETAILED DESCRIPTION

(7) FIG. 1 shows a catoptric imaging device 1 that comprises a laser guide 2 for guiding a laser beam 24 from a laser source 5, a catoptric assembly 12 arranged below the laser guide 2 for receiving the laser beam 24, and an imaging unit 7 arranged above the laser guide 2 for receiving the optical information provided by a part of the catoptric assembly 12. As shown, the imaging unit 7, the laser guide 2, and the catoptric assembly 12 are aligned along a common measuring axis 13. The measuring axis 13 matches the catoptric imaging device longitudinal axis.

(8) The catoptric assembly 12 comprises a first conical surface 3 positioned to receive the laser beam 24 guided by the laser guide 2. The catoptric assembly 12 further comprises a second surface comprising a frustoconical surface 4 to receive the drill optical information and reflect it towards the imaging unit 7. Both surfaces 3, 4 are coaxially aligned with respect to the measuring axis 13. The frustoconical surface 4 is arranged below the first surface 3, and is wider than the first conical surface 3, that is, the smallest diameter of the frustoconical surface 4 is larger than the largest diameter of the first surface 3.

(9) The shape of the first surface 3 causes the laser beam 24 conducted by the laser guide 2 to be reflected as a cone beam 9. The cone beam strikes a complete annular cross section of the drill 6 to be measured.

(10) The frustoconical shape allows, in first place, collecting the cone beam reflections 10 onto the drill 6 to be measured, and in second place, reflecting the cone beam reflections upwards toward the imaging unit 7.

(11) The imaging unit 7 comprises an imaging element 25 for photoelectrically converting the optical image received from the frustoconical surface 4 reflections, into image information. The imaging element 25 is a semiconductor element, typically a CCD or a CMOS image sensor, and has an imaging function of receiving light from an object and capturing an image of the object. Further, the imaging unit 7 comprises image processor 26 for processing the image information to obtain at least one drill measure.

(12) According to a preferred embodiment, the image processor 26 is further configured to calculate the diameter of the drill 6 from the drill image information.

(13) According to another preferred embodiment, the image processor 26 is further configured to calculate the cylindricity of the drill 6 from the drill image information. This way, the catoptric imaging device 1 allows measuring the drill tilting.

(14) According to another preferred embodiment, the image processor 26 is further configured to calculate the ovalization of the drill 6 from the drill image information. This way, the disclosure herein allows measuring the drill deformation.

(15) In a preferred embodiment, the laser guide 2 comprises an optical fiber 15 for guiding the laser beam 24 from a laser source 5, and a probe 16 for enclosing the optical fiber 15. The probe longitudinal axis matches the measuring axis 13.

(16) Preferentially, the optical fiber 15 is mounted along to a ferrule 17 whose diameter matches the diameter of the fiber cladding. The optical fiber ferrule 17 holds the optical fiber 15 and helps to align and secure the fiber mechanically.

(17) As shown in FIG. 1, the probe 16 may comprise different sections. Preferentially, the probe 16 comprises a first section 18 made of steel, and a second section 19 made of a translucent material. The translucent material is such that allows a laser beam to pass through it. Preferably, such translucent material will be glass.

(18) According to a preferred embodiment, the catoptric assembly 12 has a single body formed by an upper part comprising a conical section having the conical surface 3, and a lower part having a frustoconical configuration and having the frustoconical surface 4.

(19) In a preferred embodiment, as shown in FIG. 1, the first conical surface 3 is fitted at one end of the probe 16. To improve this fitting, the upper part of the body may comprise a tubular section 27 below the conical section, which is flush with the conical section. Also, this tubular section 27 eases the coupling and uncoupling of the catoptric assembly 12 to the probe 16. Additionally, this tubular section 27 may form a shoulder with the frustoconical surface 4 to receive the end of the probe 16.

(20) At the opposite end, the probe 16 is coupled to the imaging unit 7. The imaging unit 7 may further comprise a plurality of lenses 20 that condense light from outside before reaching the imaging element 25. The plurality of lenses 20 are assembled in a lens holder so that respective centers thereof are positioned on the same axis, the measuring axis 13.

(21) Preferably, as shown in FIG. 1, the lens holder comprises at its base a clamping plate 21 for engaging the probe 16 and supporting the imaging unit 7 outside the drill to inspect.

(22) As shown in FIGS. 1 and 2, the laser guide 2 may further comprise a lens 14 placed at the optical fiber 15 output to collimate the laser beam 24 guided by the fiber 15. Preferably, the lens 14 is a GRIN lens, suitable for confined spaces.

(23) FIG. 2 shows the effect of the GRIN lens 14. The lens 14 collimates the laser beam 24 upon exiting the optical fiber 15 to generate a narrow beam. This narrow beam is directed to the vertex of the first conical surface 3 to generate a conical beam 9. The GRIN lens length is selected such that at the exit face of the GRIN lens the beam exhibits a slight convergence, focusing to a distance given by the expected location of the drill wall. Therefore, at that distance the vertical width of the conical beam is minimal.

(24) The conical beam 9 strikes onto a complete cross section of the drill 6 to measure. This way, the device 1 provides information of the entire section without having to rotate the device 1 about the measuring axis 13, or having to contact the drill 6. This results on a simpler and faster measuring task.

(25) The cone beam reflections 10 are received by the frustoconical surface 4, and subsequently reflected towards the imaging unit 7 location. The imaging unit 7 converts drill optical image into drill image information.

(26) FIG. 3 schematically shows the optical paths followed by the laser beam 24 since outputs the optical fiber until taking the imaging unit 7 direction. As shown, the frustoconical surface 4 configuration determines the measurable diameter range. The smallest diameter 22 of the frustoconical surface 4 sets the minimum measurable diameter, whereas the largest diameter 23 sets the maximum measurable diameter.

(27) FIG. 3 also shows in a schematic way the potential images that would be formed from the different frustoconical surface reflections 11. In particular, the images 31, 30 corresponding to the minimum and maximum measurable diameters, and the image 29 corresponding to the diameter of the measured drill 6.

(28) According to a preferred embodiment, the imaging unit 7 further comprises a display configured to display the drill image information. FIG. 4 represents the image that would show the display in the exemplary case of FIG. 3. For illustrative purposes, FIG. 4 additionally shows in dashed lines the images 31, 30 corresponding to the smallest 22 and largest diameter 23 of the frustoconical surface 4, which informs about minimum and maximum measurable diameters. The area between the minimum and maximum measurable diameters determines the measurable area of the device 1.

(29) FIG. 5 shows the geometry associated to the catoptric assembly 12 configuration shown in FIGS. 1, 2 and 3, and to the optical paths followed by the laser beam since exiting the laser guide until directed towards the imaging unit 7.

(30) The narrow beam, generated at the GRIN lens 14 output, strikes the apex of the first conical surface 3. The first conical surface 3 forms a half angle with respect to a vertical plane. Hence, the narrow beam becomes a narrow cone beam 9 with aperture with respect to a horizontal plane. The cone beam 9 strikes onto the drill to be measured, and the light diffused by the drill wall is reflected in the frustoconical surface 4, which forms a half angle with respect to the vertical plane.

(31) Assuming that the -angle is 45 sexagesimal degrees, the image processor 26 is configured to obtain at least one drill measure considering the following parameters: R.sub.min: minimum measurable radius, R.sub.max: maximum measurable radius, R.sub.1: first conical surface diameter, R.sub.2: smallest radius of the frustoconical surface, R.sub.3: largest radius of the frustoconical surface (catoptric imaging device radius), : half angle of the first conical surface, : cone beam angle with respect to a horizontal plane, : half angle of the frustoconical surface.

(32) With these parameters, the image processor 26 will make use of the following relations to finally obtain at least one drill measure:

(33) $\begin{array}{cc}\tan =\frac{R_3-R_2}{R_{\max }-R_{\min }}& \left[1\right]\\ \tan =\frac{1}{\tan }& \left[2\right]\\ h_1=\frac{R_1}{\tan }& \left[3\right]\\ h_2=R_{\min }\tan -h_1& \left[4\right]\\ h_3=R_3-R_2& \left[5\right]\end{array}$

(34) From the above mentioned relations, the image processor 26 is adapted to calculate the diameter of the measured drill 6, the tilt of the drill, or the drill deformation. Also, the image processor 26 is adapted to detect small defects, such as tool grooves.

(35) Finally, the catoptric imaging device 1 can be used to characterize a complete profile of a drill by just including a laser source to feed the laser guide, and a scanning system for moving the catoptric imaging device along the measuring axis.

(36) While at least one exemplary embodiment of the present invention(s) has been shown and described, it should be understood that modifications, substitutions and alternatives may be apparent to one of ordinary skill in the art and can be made without departing from the scope of the disclosure described herein. This application is intended to cover any adaptations or variations of the specific embodiments discussed herein. In addition, in this disclosure, the terms comprise or comprising do not exclude other elements or steps, and the terms a or one do not exclude a plural number. Furthermore, characteristics or steps which have been described with reference to one of the above exemplary embodiments may also be used in combination with other characteristics or steps of other exemplary embodiments described above.