IP Library › Granted Patent US 8,488,113
Granted Patent B2
US 8,488,113 · App. 12/896,435 · Granted Jul 16, 2013

Device and method for optical 3D measurement and for color measurement

Inventors: Frank Thiel (Ober-Ramstadt, DE); Peter Fornoff (Reichelsheim, DE)
Assignee: Sirona Dental Systems GmbH
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Quick Facts
Patent No.
US 8,488,113
App. No.
12/896,435
Granted
Jul 16, 2013
Kind
B2
Abstract

The invention relates to a device and a method for optical 3D measurement, wherein said device can be switched between a first mode for optical 3D measurement using a chromatic confocal measurement method or the triangulation measurement method and a second mode for colorimetric measurement. In the first mode, a broad-band illuminating beam is focused onto a first plane and in the second mode the broad-band illuminating beam is focused onto a second plane other than the first plane at a distance d from the surface of the object to be measured.

Claims (47)

1. A device that operates in a first mode in which the device performs an optical 3D measurement and a second mode in which the device performs a colorimetric measurement, the device comprising:

a base unit including a light source, a beam splitter, a diaphragm, and a color sensor;

a first handpiece including a first objective that focuses a broad-band illuminating beam from the light source onto a first plane of a surface of an object to be measured when the device is operating in the first mode;

a second handpiece including a second objective that focuses the broad-band illuminating beam from the light source onto a second plane other than the first plane at a distance from the surface of the object to be measured when the device is operating in the second mode, wherein,

when the device is operating in said second mode, a plurality of points of focus for a plurality of wavelengths of said illuminating beam are at a distance from said first plane and the illuminating beam is reproduced out-of-focus as a measurement area on the surface of the object to be measured; and

a light guide, wherein said light guide interconnects the base unit and the first handpiece when the device is operating in the first mode, and said light guide interconnects said base unit and the second handpiece when the device is operating in the second mode.

2. A device that operates in a first mode in which the device performs an optical 3D measurement and a second mode in which the device performs a colorimetric measurement, the device comprising:

a base unit including a light source, a beam splitter, a diaphragm, and a color sensor; and

a handpiece; and

a light guide connecting the handpiece to the base unit,

wherein the handpiece includes:

a first objective that focuses a broad-band illuminating beam from the light source onto a first plane of a surface of an object to be measured when the device is operating in the first mode;

a second objective that focuses the broad-band illuminating beam from the light source onto a second plane other than the first plane at a distance from the surface of the object to be measured when the device is operating in the second mode; and

a revolving mechanism that revolves the first objective into the optical path of the illuminating beam when the device is operating in the first mode, and that revolves said second objective into the optical path of said illuminating beam when the device is operating in the second mode.

3. The device as defined in claim 1 , wherein, the first objective is inserted into the optical path of the illuminating beam when the device is operating in the first mode, and the second objective is inserted into the optical path of the illuminating beam when the device is operating in the second mode.

4. The device as defined in claim 1 , wherein

said illuminating beam comprises plural parallel individual component beams extending in a single plane; and

when the device is operating in the first mode, the first objective focuses the individual component beams to focal points disposed in a row on said first plane of the surface of the object to be measured, and

when the device is operating in the second mode, the second objective focuses the individual component beams to focal points disposed in a row on said second plane other than said first plane such that said individual component beams provide out-of-focus superimposed circles on the surface of the object to be measured to form said measurement area.

5. The device as defined in claim 1 , wherein the diaphragm is disposed in an optical path of a monitoring beam of light reflected from the object, the diaphragm being confocal to a focal point formed on the surface of the object to be measured, and wherein

the diaphragm has a first diameter and the device has a first depth of field when the device is operating in the first mode, and the diaphragm has a second diameter and the device has a second depth of field when the device is operating in the second mode, the first diameter being greater than the second diameter, and the first depth of field being shorter than the second depth of field.

6. The device as defined in claim 5 , further comprising an adjuster that controls and varies the diameter of the diaphragm.

7. The device as defined in claim 5 , wherein said diaphragm comprises first and second replaceable diaphragms, said first replaceable diaphragm being utilized when the device is operating in the first mode, and said second replaceable diaphragm being utilized when the device is operating in the second mode, a diameter of the first diagram being larger than a diameter of the second diaphragm.

8. A method for optical 3D measurement and colorimetric measurement, the method comprising:

selecting a device that operates in a first mode performing an optical 3D measurement and operates in a second mode performing a colorimetric measurement; and

switching said device between said first and second modes, wherein

when the device is operating in the first mode a broad-band illuminating beam is focused onto a first plane of a surface of an object to be measured, and

when the device is operating in the second mode, said broad-band illuminating beam is focused onto a second plane other than said first plane at a distance from the surface of the object to be measured, such that a plurality of focal points for a plurality of wavelengths of said illuminating beam are at a distance from said first plane and said illuminating beam is reproduced out-of-focus and forms a circular feature as a measurement area on the surface of the object to be measured.

9. The method as defined in claim 8 , wherein the devices comprises a first objective and a second objective, and when the device is switched from operating in the first mode to operating in the second mode, the first objective is revolved out of an optical path of the illuminating beam and the second objective is revolved into the optical path of said illuminating beam.

10. The method as defined in claim 8 , wherein the device comprises a first objective and a second objective, and when said device is switched from the first mode to the second mode, said first objective is removed from an optical path of said illuminating beam and said second objective is inserted into the optical path of said illuminating beam.

11. The method as defined in claim 8 , wherein said device comprises a first handpiece including a first objective for operation in the first mode, and a second handpiece including a second objective for operation in the second mode, wherein

when the device is switched from the first mode to the second mode, the first handpiece is disconnected from the base unit and the second handpiece is connected to said base unit.

12. The method as defined in claim 8 , wherein the illuminating beam comprises plural parallel individual component beams extending in a single plane and the method further comprises:

focusing the individual component beams to focal points disposed in a row on said first plane of the surface of the object to be measured when the device is operating in the first mode; and

focusing the individual component beams onto said second plane, such that said individual component beams are reproduced out-of-focus on the surface of the object to be measured and are superimposed forming the measurement area when the device is operating in the second mode.

13. The method as defined in claim 8 , wherein the device comprises a diaphragm disposed in an optical path of a monitoring beam of light reflected from the object, the diaphragm being confocal to a focal point formed on the surface of the object to be measured, the method further comprising:

adjusting a diameter of the diaphragm to have a first diameter with the device having a first depth of field when the device is operating in the first mode, the diaphragm having a second diameter with the device having a second depth of field when the device is operating in the second mode, wherein

the first diameter is larger than the second diameter, and the first depth of field is shorter than the second depth of field.

14. The method as defined in claim 13 , wherein the device comprises an adjuster that electronically controls the diameter of said diaphragm.

15. The device as defined in claim 1 , wherein points of focus for all wavelengths of said illuminating beam are at a distance from said first plane and the illuminating beam is an out-of-focus circle in said second mode.

16. The method as defined in claim 8 , wherein points of focus for all wavelengths of said illuminating beam are at a distance from said first plane and the illuminating beam has a spectrum of daylight.

17. A device that operates in a first mode in which the device performs an optical 3D measurement and a second mode in which the device performs a colorimetric measurement, the device comprising:

a base unit including a light source, a beam splitter, a diaphragm, and a color sensor; and

a handpiece, wherein the handpiece includes:

a first objective that focuses a broad-band illuminating beam from the light source onto a first plane of a surface of an object to be measured when the device is operating in the first mode;

a second objective that focuses the broad-band illuminating beam from the light source onto a second plane other than the first plane at a distance from the surface of the object to be measured when the device is operating in the second mode, and

wherein, the first objective is inserted into the optical path of the illuminating beam when the device is operating in the first mode, and the second objective is inserted into the optical path of the illuminating beam when the device is operating in the second mode.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Dec 16, 2010
From: THIEL, FRANK; FORNOFF, PETER
To: SIRONA DENTAL SYSTEMS GMBH
Reel/Frame 025508/0968 →
Priority Claims (1)
DE 10 2008 017 481 · Apr 3, 2008 · national
Continuity (2)
Continuation PCTEP2009053912 · Apr 2, 2009
Related Publication 20110080576A1 · Apr 7, 2011