Method and apparatus for three-dimensional optical scanning of interior surfaces
Assignee3Shape ApS
InventorsNikolaj Deichmann, Tais Clausen, Rune Fisker, Christophe Vasiljev Barthe
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Abstract
The invention concerns the three-dimensional scanning of interior surfaces or cavities of limited dimensions or with restricted accessibility by providing a probe-shaped non-contact adpated to perform a scan 360° around the axis of the probe and a method for scanning. The invention furthermore relates to the creation of high precision three-dimensional replicas of real objects using 3-D scan data obtainable with the scanner according to the invention. Furthermore, the invention relates to a specific embodiment for scanning the human ear and ear canal.
Claims101
A scanner for three-dimensional scanning of interior surfaces comprising
- at least one light source adapted to create and project structured light producing a pattern on the interior surface of an object,
- at least one camera, adapted to record 2-D images of the pattern,
- data processing means adapted to convert 2-D image information into 3-D real world co-ordinates,
- at least one position sensor adapted to provide the relative position and orientation of the scanner during successive scans,
- the point of emission of light as well as the point of accumulation of reflected light for the camera being located on a probe having an axis,
- the at least one light source and the at least one camera being adapted to perform a scan 360° around the axis, and
- the probe being adapted to be entered into a cavity.
The scanner according to any of the preceding claims, wherein the probe is made from a material selected from the group consisting of an alloy, aluminium, kevlar, a polymer, ceramics, and carbon.
The scanner according to any of the preceding claims, wherein the probe is made from a material selected from the group consisting of polymers, such as plastic polymers, rubber, and silicone.
The scanner according to any of the preceding claims, wherein the pattern of structured light comprises at least one ray of light forming at least one point on the surface.
The scanner according to any of the preceding claims, wherein the at least one light source is adapted to create and project rectangular shaped rays forming a distorted checkerboard pattern on the interior surface.
The scanner according to any of the preceding claims, wherein the pattern of structured light comprises at least one planes of light forming at least one contour on the surface
The scanner according to any of the preceding claims, wherein the pattern of structured light comprises at least one cone of light.
The scanner according to any of the preceding claims, whereby the light source intensity is varied depending on the surface and/or colour of the object to be scanned.
The scanner according to any of the preceding claims, wherein the at least one light source is arranged such that structured light is emitted in different directions covering 360° around the probe.
The scanner according to any of the preceding claims, wherein the at least one camera comprises a sensor array.
The scanner according to any of the preceding claims, wherein the at least one camera comprises a CCD.
The scanner according to any of the preceding claims, wherein the at least one camera comprises a CMOS.
The scanner according to any of the preceding claims, wherein the light detecting component of the camera has a cross section in a direction perpendicular to the direction of incident light of less than 10 mm, such as less than 9 mm, for example less than 8 mm, such as less than 7 mm, for example less than 6 mm, such as less than 5 mm, for example less than 4 mm, such as less than 3 mm, for example less than 1 mm, such as less than 0.5 mm, for example less than 0.25 mm, such as less than 0.1 mm, for example less than 0.01 mm.
The scanner according to any of the preceding claims, wherein the camera comprises an array of at least 125*125 pixels, more preferably at least 250*250 pixels, more preferably more than 500*500 pixels, more preferably more than 1000*1000 pixels, such as more than 2000*2000 pixels, for example more than 4000*4000 pixels, such as more than 8000*8000 pixels, for example more than 10,000*10,000 pixels, such as more than 25,000*25,000 pixels, for example more than 50,000*50,000 pixels, such as more than 100,000*100,000 pixels, for example more than 250,000*250,000 pixels, such as more than 500,000*500,000 pixels, for example more than 1,000,000*1,000,000 pixels.
The scanner according to any of the preceding claims, wherein the at least one camera is colour sensitive.
The scanner according to any of the preceding claims, further comprising a filter in the light path between the object surface and the camera being adapted to filter light from other light sources than the individual light sources of the scanner.
The scanner according to any of the preceding claims, wherein the location of the point of emission of light and the point of recording reflected light as well as the angle of emission and recording with respect to the axis of the probe are chosen to give an angle between incident light on the object and light reflected from the object of approximately 20-30°.
The scanner according to any of the preceding claims, wherein the location of the point of emission of light and the point of recording reflected light as well as the angle of emission and recording with respect to the axis of the probe are chosen to give a scan of the surface lying ahead of the end of the probe.
The scanner according to any of the preceding claims, wherein the location of the point of emission of light and the point of recording reflected light as well as the angle of emission and recording with respect to the axis of the probe are chosen to give a scan of the surface lying approximately around the end of the probe.
The scanner according to any of the preceding claims, wherein the location of the point of emission of light and the point of recording reflected light as well as the angle of emission and recording with respect to the axis of the probe are chosen to give a scan of the surface lying behind the end of the probe.
The scanner according to any of the preceding claims comprising a motor adapted to rotate the scanner around its axis.
The scanner according to any of the preceding claims, comprising a motor being adapted to translate the scanner along its axis.
The scanner according to any of the preceding claims, comprising a motor being adapted to translate the scanner in space.
The scanner according to any of the preceding claims, further comprising at least one mirror and/or prism to reflect light emitted from the light source.
The scanner according to any of the preceding claims, further comprising at least one mirror and/or prism to direct light reflected from the interior surface to the camera.
The scanner according to any of the preceding claims, wherein the at least one light source is located in a box attached to the probe, the at least one light guide being connected with the point of emission of light with a light guide.
The scanner according to any of the preceding claims, wherein at least one light source is located near the point of emission of light.
The scanner according to any of the preceding claims, wherein the at least one camera is located in a box attached to the probe, the at least one camera being connected with the point of recording of reflected light by a light guide.
The scanner according to any of the preceding claims, wherein a camera is located near the point of recording of reflected light.
The scanner according to any of the preceding claims, wherein the position sensor comprises a mechanical position sensor.
The scanner according to any of the preceding claims, wherein the position sensor comprises a sonic position sensor.
The scanner according to any of the preceding claims, wherein the position sensor comprises an optical position sensor.
The scanner according to any of the preceding claims, wherein the position sensor comprises a magnetic position sensor.
The scanner according to any of the preceding claims, further comprising a collision detector adapted to measure the distance from the tip of the probe to the bottom of the interior surface.
The scanner according to any of the preceding claims, further comprising a protector adapted to protect the surface and the scanner head in the case of collisions.
The scanner according to any of the preceding claims, further comprising a window of transparent material adapted to protect the components against dirt.
The scanner according to any of the preceding claims, further comprising a disposable cover.
A method for scanning interior surfaces comprising the steps of
- i) entering a probe shaped scanner having an axis into a cavity,
- ii) creating and projecting structured light from a first point on the probe producing a pattern on an interior surface of an object, and at a second point of the probe, recording 2D images of the pattern reflected from the interior surface, thereby performing a scan 360° around the axis of the probe,
- iii) determining 2D co-ordinates of the images of the pattern,
- iv) determining the relative position and orientation of the scanner during successive scans with at least one position sensor,
- v) combining a series of images to obtain 3D real world co-ordinates of the interior surface.
Dependencies are inferred from the claim text.