CAMERA FOR RECORDING SURFACE STRUCTURES, SUCH AS FOR DENTAL PURPOSES

• US 20100157019A1
• Filed: 12/18/2008
• Published: 06/24/2010
• Est. Priority Date: 12/18/2008
• Status: Active Grant

• Current Assignee: Sirona Dental Systems GmbH (Sirona Dental Systems Incorporated)
• Original Assignee: Sirona Dental Systems GmbH (Sirona Dental Systems Incorporated)
• Inventors: SCHWOTZER, AXEL, SCHMIDT, VOLKER
• Granted Patent: US 9,282,926 B2
• Time in Patent Office: Days
• US Class Current: 348/46
• CPC Class Codes: A61B 1/00163 Optical arrangements A61B1/002, A61B1/06 take precedence
• CPC Class Codes: A61B 1/00193 adapted for stereoscopic vision
• CPC Class Codes: A61B 1/00194 adapted for three-dimensional imaging
• CPC Class Codes: A61B 1/046 for infrared imaging
• CPC Class Codes: A61B 1/0605 for spatially modulated illumination
• CPC Class Codes: A61B 1/0646 with illumination filters
• CPC Class Codes: A61B 1/0669 at proximal end of an endoscope
• CPC Class Codes: A61B 1/24 for the mouth, i.e. stomatoscopes, e.g. with tongue depressors tongue depressors per se A61B13/00; Instruments for opening or keeping open the mouth combined with saliva removers A61C17/00; mouth openers for animals A61D15/00
• CPC Class Codes: A61B 5/0084 for introduction into the body, e.g. by catheters A61B5/1459 takes precedence
• CPC Class Codes: A61B 5/4547 Evaluating teeth
• CPC Class Codes: A61C 1/088 Illuminating devices or attachments for examination of the mouth A61B1/24 and A61B1/06
• CPC Class Codes: A61C 9/006 projecting one or more stripes or patterns on the teeth

Abstract

A 3-D camera for obtaining an image of at least one surface of at least one object. The camera comprises a light source, arranged to illuminate the object, wherein a light beam emitted from the light source defines a projection optical path. The camera also includes at least one first aperture having a first predetermined size, interposed in the projection optical path such that the light beam passes through it. An image sensor receives light back-scattered by the object, the back-scattered light defining an observation optical path. At least one second aperture having a second predetermined size, is interposed in the observation optical path such that the back-scattered light passes through it. In one example embodiment of the invention, the first predetermined size is greater than the second predetermined size, and at least one optic is arranged in both the projection and observation optical paths.

Claims

1. A camera for obtaining an image of at least one surface of at least one object, the camera comprising:

a light source, arranged to illuminate the object, wherein a light beam emitted from said light source defines a projection optical path;

at least one first aperture having a first predetermined size, the at least one first aperture being interposed in the projection optical path such that the light beam passes through it;

an image sensor for receiving light back-scattered by the at least one surface of the at least one object, the back-scattered light defining an observation optical path; and

at least one second aperture having a second predetermined size, the at least one second aperture being interposed in the observation optical path such that the back-scattered light passes through it,

wherein the first predetermined size and the second predetermined size are different from each other.

2. A camera according to claim 1, wherein the camera is a 3-D camera.

3. A camera according to claim 1, wherein the first predetermined size is greater than the second predetermined size.

4. A camera according to claim 1, wherein the at least one object is a dental structure.

5. A camera according to claim 1, further comprising a reference pattern projector arranged in the projection optical path to form an image on the at least one surface.

6. A camera according to claim 5, wherein the reference pattern projector is an optical grid having a predetermined pattern to form the image.

7. A camera according to claim 1, further comprising at least one collimator arranged in the projection optical path.

8. A camera according to claim 1, further comprising at least one optical block arranged in at least one of the projection optical path and the observation optical path.

9. A camera according to claim 8, wherein the at least one optical block is polarized.

10. A camera according to claim 1, further comprising at least one optical lens arranged in at least one of the projection optical path and the observation optical path.

11. A camera according to claim 8, further comprising plural optical lenses arranged in at least one of the projection optical path and the observation optical path, wherein the lenses are tilted with respect to one another.

12. A camera according to claim 1, further comprising at least one optical prism in at least one of the projection optical path and the observation optical path.

13. A camera according to claim 1, further comprising plural optical objectives arranged in at least one of the projection optical path and the observation optical path, on opposite sides of the apertures.

14. A camera according to claim 1, wherein at least one of the first and second apertures is elliptical in shape.

15. A camera according to claim 14, further comprising a reference pattern projector arranged in the projection optical path to form an image on the at least one surface, wherein the reference pattern projector is an optical grid having a predetermined pattern to form the image, and wherein an axis along which the at least one aperture that is elliptical in shape extends is substantially perpendicular to an axis along which at least part of the predetermined pattern extends.

16. A camera according to claim 1, wherein at least one of the first and second apertures is at least semi-circular in shape.

17. A camera according to claim 1, wherein one of the first and second apertures is elliptical in shape, and at least part of another one of those apertures forms at least part of a circle.

18. A camera according to claim 17, wherein the circle has at least one side cut.

19. A camera according to claim 1, wherein at least one of the first and second predetermined sizes is controllably variable.

20. A camera according to claim 1, further comprising at least one optic arranged in both the projection optical path and the observation optical path.

21. A camera according to claim 20, wherein the at least one optic is telecentric.

22. A camera according to claim 20, wherein the at least one optic includes at least one of an objective, a lens optic, and a prism.

23. A camera according to claim 20, further comprising a housing in which the at least one optic, the light source, the first and second apertures, and the image sensor are housed.

24. A method of obtaining an image of at least one surface of at least one object, the method comprising:

providing a light beam through at least one first aperture to illuminate the at least one surface of the at least one object; and

providing light back-scattered by the at least one surface through at least one second aperture to an image sensor,

wherein the first aperture has a predetermined size that is larger than a size of the second aperture.

25. A method as set forth in claim 24, wherein the method is performed by a 3-D camera.

26. A method as set forth in claim 24, further comprising controllably varying at least one of the first and second predetermined sizes.

27. A method as set forth in claim 24, wherein the light beam and back-scattered light are provided in a single camera that comprises a plurality of optics, each optic being arranged in at least one path through which the light beam and back-scattered light travel.