# US 11,439,482 B2 · Intraoral scanner

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- Number: US 11,439,482 B2
- Document ID: US11439482B2
- Status: Granted
- Kind: B2
- Application number: 16/446,596
- Filed: 2019-06-19
- Published: 2019-12-26
- Granted: 2022-09-13
- Earliest claimed: 2018-06-21
- Assignees: Qisda Corporation
- Applicants: Qisda Corporation
- Inventors: Chih-Ming Hu; Chih-Chieh Tsung
- Web page: https://patentgrep.com/patent/US11439482B2

## CPC

- A61C 9/0053: {Optical means or methods, e.g. scanning the teeth by a laser or light beam}
- A61C 9/006: {projecting one or more stripes or patterns on the teeth}
- A61B 1/00096: {Optical elements}
- A61B 1/00177: {for 90 degrees side-viewing}
- A61B 1/00179: {for off-axis viewing}
- A61B 1/0623: {for off-axis illumination}
- A61B 1/0646: {with illumination filters}
- A61B 1/0684: {using light emitting diodes [LED]}
- A61B 1/24: for the mouth, i.e. stomatoscopes, e.g. with tongue depressors; Instruments for opening or keeping open the mouth
- A61B 1/247: with means for viewing areas outside the direct line of sight, e.g. dentists' mirrors
- G02B 27/0018: {with means for preventing ghost images (anti-reflection coatings G02B1/11)}
- G02B 27/286: {for controlling or changing the state of polarisation, e.g. transforming one polarisation state into another (G02B5/3083 takes precedence; light guide coupling means utilising polarising elements G02B6/34)}
- A61C: DENTISTRY; APPARATUS OR METHODS FOR ORAL OR DENTAL HYGIENE (non-driven toothbrushes A46B; {tongue scrapers A61B17/24;} preparations for dentistry A61K6/00; preparations for cleaning the teeth or mouth A61K8/00, A61Q11/00)
- A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D)
- G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS

## Abstract

An intraoral scanner includes a casing, a light source disposed in the casing, a reflection plate obliquely disposed in the casing for reflecting light of the light source to an object to be scanned through an opening of the casing, a transparent plate, and a receiver adjacent to the light source. A projection optical axis of the light source forms a first oblique angle with a receiving optical axis of the receiver. The receiver receives light after being incident to the object to be scanned and then reflected to the receiver by the reflection plate. The transparent plate is disposed between the light source and the reflection plate or covers the opening. The projection optical axis forms a second oblique angle with a norm of the transparent plate to make a reflection angle range of light reflected by the transparent plate fall outside a receiving angel range of the receiver.

## Claims

### Claim 1

An intraoral scanner comprising:
a casing having an opening;
a light source disposed in the casing;
a reflection plate obliquely disposed in the casing corresponding to the opening for reflecting light of the light source to an object to be scanned through the opening;
a receiver disposed in the casing and located at a side of the light source, a projection optical axis of the light source forming a first oblique angle with a receiving optical axis of the receiver, the receiver having a receiving angle range for receiving light after being incident to the object to be scanned and then reflected to the receiver by the reflection plate; and
a transparent plate disposed between the light source and the reflection plate or covering the opening, the transparent plate having a light entrance surface and a light exit surface, the light entrance surface being parallel to the light exit surface, the projection optical axis forming a second oblique angle with a norm of the light entrance surface to make a reflection angle range of light reflected by the transparent plate fall outside the receiving angle range;
wherein a light-emitting half angle of the light source is set as θP to define a light-emitting angle range of the light source relative to the projection optical axis as (−θP˜θP), the first oblique angle is set as θ1 and a light-receiving half angle of the receiver is set as θc to define the receiving angle range relative to the receiving optical axis as (−θc−θ1˜θc−θ1), the second oblique angle is set as θ2 to define the reflection angle range as (−θp−2θ2˜θp−2θ2) relative to the norm, and the second oblique angle conforms to the following equations:
(−θp−2θ2)≥(+θc−θ1); or
(+θp−2θ2)≤(−θc−θ1).

### Claim 2 (depends on 1)

The intraoral scanner of claim 1, wherein the transparent plate comprises a polarizer and is disposed between the light source and the reflection plate.

### Claim 3 (depends on 1)

The intraoral scanner of claim 1, wherein the transparent plate is a transparent protection sheet covering the opening.

### Claim 4

An intraoral scanner comprising:
a casing having an opening;
a light source disposed in the casing;
a reflection plate obliquely disposed in the casing corresponding to the opening for reflecting light of the light source to an object to be scanned through the opening;
a receiver disposed in the casing and located at a side of the light source, a projection optical axis of the light source forming a first oblique angle with a receiving optical axis of the receiver, the receiver having a receiving angle range for receiving light after being incident to the object to be scanned and then reflected to the receiver by the reflection plate; and
a transparent plate disposed between the light source and the reflection plate or covering the opening, the transparent plate having a light entrance surface and a light exit surface, the light entrance surface being perpendicular to the projection optical axis, the projection optical axis forming a second oblique angle with a norm of the light entrance surface to make a reflection angle range of light reflected by the transparent plate fall outside the receiving angle range, and the light exit surface being tilted outwardly relative to the light entrance surface by the second oblique angle;
wherein a refractive index of the transparent plate is set as n, a light-emitting half angle of the light source is set as θP to define a light-emitting angle range of the light source relative to the projection optical axis as (−θP˜θP), the first oblique angle is set as θ1 and a light-receiving half angle of the receiver is set as θc to define the receiving angle range relative to the receiving optical axis as (−θc−θ1˜θc−θ1), the second oblique angle is set as θ2, and an upper reflection angle and a lower reflection angle of the reflection angle range relative to the projection optical axis are set as θb and θa respectively and conform the following equations:
θa=sin−1[sin θp*cos(2θ2)+(√(n2−sin2 θp))*sin(2θ2)];
θb=sin−1[sin θp*cos(2θ2)−(√(n2−sin2 θp)*sin(2θ2)]; and
θb≥(θc−θ1) or θa≤(−θc−θ1).

### Claim 5 (depends on 4)

The intraoral scanner of claim 4, wherein the transparent plate comprises a polarizer and is disposed between the light source and the reflection plate.

### Claim 6 (depends on 4)

The intraoral scanner of claim 4, wherein the transparent plate is a transparent protection sheet covering the opening.