Sheath for a tip of a scanning device and system thereof

Abstract

The present invention provides in a first aspect a sheath for an intraoral scanning tip, where polarization is not substantially altered during scanning.

1 . (canceled) 
     
     
         2 . A disposable sheath for a tip of an intraoral scanning device, wherein the sheath is adapted for single-use, the sheath comprising:
 a rigid hollow body obtained by injection-molding, wherein the body is made of one or more polymers adapted to be of single-use, the hollow body comprising a distal sheath-end and a proximal sheath-end, wherein the proximal sheath-end forms a sheath-opening that is dimensioned with respect to the tip, such that the sheath is configured to replaceably fit around the tip of the scanning device; and   an optical window located in the body near the distal sheath-end such that when the sheath is replaceably mounted to the tip via the sheath-opening, the optical window covers at least a part of an optical aperture of the tip, wherein the optical window is injection-molded.   
     
     
         3 . The disposable sheath according to  claim 2 , wherein the optical window is made of a material configured for not substantially altering the polarization of the light that exits and enters the intraoral scanning device through the optical aperture of the tip. 
     
     
         4 . The disposable sheath according to  claim 2 , wherein the optical window is produced by special processing equipment which reduces stress in the optical window. 
     
     
         5 . The disposable sheath according to  claim 2 , wherein the optical window is an integrated part of the hollow body. 
     
     
         6 . The disposable sheath according to  claim 2 , wherein the optical window has a thickness of more than 400 microns. 
     
     
         7 . The disposable sheath according to  claim 2 , wherein the optical window is larger than 10 mm by 10 mm. 
     
     
         8 . The disposable sheath according to  claim 2 , wherein the optical window is glued, sealed, or welded into the hollow body. 
     
     
         9 . The disposable sheath according to  claim 2 , wherein the material of the optical window exhibits low birefringence and at the same time also provide(s) high optical clarity. 
     
     
         10 . The disposable sheath according to  claim 2 , wherein the refractive index of the optical window differ less than 1% along two optical directions, corresponding to a birefringence of less than 100.000 nm/cm. 
     
     
         11 . The disposable sheath according to  claim 2 , wherein the optical window has a birefringence of 10.000 nm/cm or less. 
     
     
         12 . The disposable sheath according to  claim 2 , wherein the optical window is birefringent, whereby the optical window has two refractive indices, no and ne, wherein no and ne differ from each other by less than 1%. 
     
     
         13 . The disposable sheath according to  claim 2 , wherein the hollow body and the optical window is made as a one-piece, injection-molded sheath. 
     
     
         14 . The disposable sheath according to  claim 2 , wherein the material of the optical window has a hardness that is selected to withstand the impact of teeth in an intraoral cavity. 
     
     
         15 . The disposable sheath according to  claim 2 , wherein the optical window is made of Poly(methyl methacrylate) (PMMA). 
     
     
         16 . The disposable sheath according to  claim 2 , wherein the hollow body is made of a polyester resin composition and a polycarbonate resin composition. 
     
     
         17 . The disposable sheath according to  claim 2 , wherein the optical window is planar and comprises a hydrophilic surface. 
     
     
         18 . The disposable sheath according to  claim 2 , wherein the optical window is sealed and provides no entrance into the hollow body of the disposable sheath. 
     
     
         19 . A scanning system comprising:
 an intraoral scanning device configured for forming a 3D model of an intraoral object such as teeth and gingiva, the scanning device comprising a tip, said tip comprising an optical aperture; and   a disposable sheath according to  claim 2 , wherein the sheath is configured to be replaceably mounted to cover at least a part of the tip of the intraoral scanning device.   
     
     
         20 . The scanning system according to  claim 19 , wherein the optical window of the sheath covers the optical aperture of the tip such that the field-of-view is maintained. 
     
     
         21 . The scanning system according to  claim 19 , wherein the tip further comprises a mirror located on an optical axis of the scanning device such that the optical axis is redirected inside the tip.