Three-dimensional oral cavity scan device using piezoelectric element based pattern module and variable focus lens

Patent metadata

Field	Value
Publication number	US-9814548-B2
Application number	US-201615322940-A
Country	US
Kind code	B2
Filing date	Apr 5, 2016
Priority date	Apr 22, 2015
Publication date	Nov 14, 2017
Grant date	Nov 14, 2017

Abstract

The present invention relates to a three-dimensional oral cavity scan device for a digital impression that obtains a three-dimensional image by processing a two-dimensional image acquired by photographing a three-dimensional subject in an oral cavity. The device includes: a pattern mask converting parallel light incident thereto into structured light; a piezoelectric plate where a mechanical vibration is generated on a surface thereof by an AC voltage applied thereto; and a power supply unit applying the AC voltage to the piezoelectric plate, wherein the piezoelectric plate moves the pattern mask in a longitudinal direction of the piezoelectric plate by using the mechanical vibration. The device can reduce noise and vibration by moving the pattern mask with an electrical method. In addition, the device can accurately measure depth of teeth by electrically controlling a focal length of structured light projected on the teeth.

First claim

The invention claimed is:

1. An oral cavity scan device obtaining a three-dimensional shape of teeth by using structured light, the device comprising:
a pattern mask converting parallel light incident thereto into the structured light;

a piezoelectric plate where a mechanical vibration is generated on a surface thereof by an AC voltage applied thereto; and
a power supply unit applying the AC voltage to the piezoelectric plate,
wherein the piezoelectric plate moves the pattern mask in a longitudinal direction of the piezoelectric plate by using the mechanical vibration generated on the surface of the piezoelectric plate.

2. The device of claim 1 , wherein the piezoelectric plate is a PZT (plumbum zirconate titanate) ceramic element.

3. The device of claim 1 , wherein the pattern mask comprises:
a light transmission line through which the parallel light passes; and
a light shielding line blocking the parallel light,
wherein the light transmission line and the light shielding line are alternately arranged in the pattern mask.

4. The device of claim 3 , wherein the piezoelectric plate is a PZT (plumbum zirconate titanate) ceramic element.

5. The device of claim 1 , further comprising:
an offset lens to which the structured light is incident, with a concave curvature formed in the offset lens; and
a reflection mirror reflecting the structured light in a direction toward a subject,
wherein the offset lens reduces a focal distance of the structured light.

6. The device of claim 5 , wherein the piezoelectric plate is a PZT (plumbum zirconate titanate) ceramic element.

7. The device of claim 5 , further comprising:
a variable focus lens adjusting the reduced focal distance of the structured light penetrating the offset lens.

8. The device of claim 7 , wherein the variable focus lens enables reflected light reflected from the subject to be incident to the offset lens so as to obtain an image of the teeth.

9. The device of claim 7 , wherein the piezoelectric plate is a PZT (plumbum zirconate titanate) ceramic element.

10. The device of claim 8 , wherein the piezoelectric plate is a PZT (plumbum zirconate titanate) ceramic element.

Assignees

• Korea Photonics Tech Inst

Inventors

• Eom Joo Beom
• Ahn Jaesung
• Lee Byeong Il
• Shin In Hee
• Park Anjin
• Lee Byeong Ha

Classifications

• A61C9/0066

  Depth determination through adaptive focusing · CPC title

• A61B1/0019

  characterised by variable lenses · CPC title

• A61B5/0062

  Arrangements for scanning · CPC title

• A61C9/006 Primary

  projecting one or more stripes or patterns on the teeth · CPC title

• A61B1/247

  with means for viewing areas outside the direct line of sight, e.g. dentists' mirrors · CPC title