Patent Description:
In a dental prosthesis manufacturing process, impression taking is an important process in manufacturing accurate prosthesis, and in the related art, an impression is taken using an impression material, and then a prosthesis is manufactured based on a produced plaster model, but there is a disadvantage in that an error occurs due to deformation of impression material and use of gypsum.

Accordingly, an optical three-dimensional (3D) scanner is used to measure oral structures such as teeth and gums using an optical 3D imaging device, and dental prostheses are manufactured using a CAD/CAM system, and in particular, in these days, a stereo vision method using images obtained from two or more imaging devices is applied to an oral scanner.

Since in the oral scanner of the stereo vision method, two or more pieces of image data are acquired by photographing a point in an oral cavity with two or more imaging devices and 3D distance information is acquired based on the image data, calibration of the oral scanner is frequently required for acquiring accurate 3D model data. For this reason, it is common to provide a calibration tool in the form of a cradle as a separate accessory to a 3D oral scanner.

Meanwhile, acquiring images of a pattern plate from various angles during calibration is helpful in improving the accuracy of calibration, but in a calibration cradle disclosed in <CIT>, the pattern plate is configured to be rotated in eight steps by <NUM> degrees in a circumferential direction and rectilinearly reciprocate in conjunction with the rotation, and thus, there is a disadvantage in that it is not possible to acquire an image of the pattern plate at any angle and depth other that a predetermined angle and depth. Prior art document <CIT> also discloses a calibration device for an oral scanner having a casing, a rotating unit and a pattern plate. In document <CIT> the rotating unit has an inclined surface which can be rotated and/or moved vertically such that images of the pattern plate can be acquired at various angles and depths.

The present invention has been made in view of solving the above-mentioned problem of the related art, and an object of the present invention is to provide a calibration device for an oral scanner having a simple structure, capable of acquiring images of a pattern plate at various angles and depths.

According to the invention as defined in independent claim <NUM>, a calibration device for an oral scanner is provided, including a casing to which an oral scanner body is coupled to an open upper portion thereof, a rotating unit rotatably provided with respect to the casing, a reflector unit disposed on a central axis of an optical device in the oral scanner body, and a pattern plate unit facing the optical device through the reflector unit, wherein in conjunction with rotation of the rotating unit, the pattern plate unit rotates in place and the reflector unit rectilinearly reciprocates with respect to the oral scanner body.

In one embodiment, the rotating unit may include a rotating shaft extending in a longitudinal direction, a first coupling portion provided on one side of the rotating shaft and coupled to the pattern plate unit, and a second coupling portion provided on the other side of the rotating shaft and coupled to the reflector unit.

In one embodiment, a handle may be provided at one end of the rotating shaft.

In one embodiment, the pattern plate unit may include a pattern plate and a first interlocking portion integrally formed with the pattern plate and engaged with the first coupling portion, and the first interlocking portion may rotate by rotation of the first coupling portion.

In one embodiment, the reflector unit may include a reflector, a support portion configured to rotatably support the reflector, and a second interlocking portion rotatably coupled to the support portion and engaged with the second coupling portion, and in conjunction with rotation of the second coupling portion, the second interlocking portion may rotate and the reflector may be rectilinearly reciprocated.

In one embodiment, the reflector unit may further include a rotation preventing member configured to prevent the rotation of the reflector with respect to the second interlocking portion.

In one embodiment, the reflector may move along an inclined surface of the rotation preventing member when the reflector rectilinearly reciprocates so that an inclination angle is adjusted.

In one embodiment, at least one of one end and the other end of the inclined surface may be formed with a stepped portion configured to restrict movement of the reflector.

In one embodiment, the pattern plate unit may include a pattern plate and an interlocking portion integrally formed with the pattern plate and engaged with the first coupling portion, and the interlocking portion may rotate by rotation of the first coupling portion.

In one embodiment, the reflector unit may include a plurality of reflectors and a support portion configured to support the reflectors and engaged with the second coupling portion, and the support portion may rectilinearly reciprocate by rotation of the second coupling portion.

In one embodiment, the reflector may include a first reflector and a second reflector, the first reflector may be disposed to form an angle of <NUM> degrees on a central axis of the optical device, the second reflector may be disposed to form an angle of <NUM> degrees on a longitudinal axis of the pattern plate unit, and the first reflector and the second reflector may be disposed in mirror symmetry to reflect a direction of light emitted from the optical device <NUM> degrees.

In one embodiment, the reflector unit may further include a guide portion coupled to a rail formed in the casing.

In one embodiment, the reflector unit may rectilinearly reciprocate along the rail when the second coupling portion is rotated.

In one embodiment, at least one of one end and the other end of the rail may be formed with a stepped portion configured to restrict movement of the reflector uni.

According to one aspect of the present invention, since in conjunction with rotation of the rotating unit, a pattern plate rotates and a reflector rectilinearly reciprocates with respect to an oral scanner body, images of the pattern plate can be acquired at various angles and depths, and thus calibration accuracy can be improved.

Effects of the present invention are not limited to the above-described effects, but should be understood to include all effects that can be deduced from features of inventions described in the detailed description or the claims of the present invention.

Hereinafter, the present invention will be described with reference to the accompanying drawings. However, the present invention may be implemented in various different forms and is not limited to the embodiments described herein. In the drawings, in order to clarify the present invention, parts that are not related to description are omitted and like reference numerals represent like elements throughout the specification.

When a part is referred to as being "connected" to another part throughout the specification, it includes not only a circumstance when the part is "directly connected" to the other part, but also a circumstance when the part is "indirectly connected" to the other part with another member interposed therebetween. In addition, when a part "includes" or "comprises" a component, unless described to the contrary, the term "includes" or "comprises" does not indicate that the part excludes another component but instead indicates that the part may further include the other component.

Terms including an ordinal number such as "first" or "second" used in this specification may be used to describe various components or steps, but the component or steps should not be limited by the ordinal numbers. A term used with an ordinal number should be construed such that the term is used for the sole purpose of distinguish one component or step from other components or steps.

<FIG> is a perspective view of a calibration device for an oral scanner according to one embodiment of the present invention. <FIG> is a perspective view of an inner space of the calibration device for an oral scanner. <FIG> is an exploded perspective view of <FIG>. <FIG> and <FIG> are cross-sectional views showing an operating process of the calibration device for an oral scanner according to one embodiment of the present invention.

With reference to <FIG> and <FIG>, a calibration device <NUM> for an oral scanner according to one embodiment of the present invention is a device for calibrating an optical device of an oral scanner, and includes a casing <NUM>, a rotating unit <NUM>, a pattern plate unit <NUM>, and a reflector unit <NUM>.

The casing <NUM> forms an outer circumferential surface of the calibration device <NUM> for an oral scanner and includes a body <NUM> for forming an inner space, an insertion portion <NUM> that is formed on one side of an upper portion of the body <NUM> and into which an oral scanner body <NUM> is inserted and supported, and a cover <NUM> formed to cover one side of the body <NUM>. In general, the oral scanner includes the oral scanner body <NUM> in which an optical device and an imaging board are disposed and a probe tip in which a reflective mirror is disposed therein, and the optical device includes a light source for emitting light toward an opening of the oral scanner body <NUM> and a pair of imaging devices for collecting light introduced through the opening onto the imaging board.

In this case, since scanning of the subject's oral cavity is performed by inserting the probe tip into a subject's oral cavity, a reflective member may be filled with moisture in the subject's oral cavity, and thus calibration accuracy may be reduced when calibration is performed with the probe tip attached. Therefore, in order to minimize the negative effect of the reflective member, it is desirable that only the oral scanner body <NUM> from which the probe tip is removed is inserted into the casing <NUM>.

Preferably, to allow the oral scanner body <NUM> to be fixed to the insertion portion <NUM>, the insertion portion <NUM> may be formed to correspond to a shape of an end of the oral scanner body <NUM>. More preferably, at the end of the oral scanner body <NUM>, a groove may be formed along a circumferential direction of the end, and around an inner circumferential surface of the insertion portion <NUM>, protrusion corresponding to the groove may be formed. In this case, when the oral scanner body <NUM> is inserted into the insertion portion <NUM>, the groove and the protrusion may be coupled so that the oral scanner body <NUM> may be firmly fixed to the insertion portion <NUM>.

As shown in <FIG>, the body <NUM> may have a trapezoidal shape in which a space is formed therein, but is not limited thereto, and various shapes may, of course, be applied. Light emitted from the light source of the oral scanner body <NUM> is incident on the reflector unit <NUM> disposed inside the body <NUM> to be described below.

Meanwhile, the pattern plate unit <NUM> according to one embodiment of the present invention is provided on an inner circumferential side of the body <NUM> so that a longitudinal axis thereof is positioned on an axis orthogonal to a central axis of the oral scanner body <NUM>. Accordingly, the pattern plate unit <NUM> faces the optical device inside the oral scanner body <NUM> through the reflector unit <NUM> to be described below, and includes a pattern plate <NUM> and a seating portion <NUM>.

In detail, the pattern plate <NUM> may be formed in a square shape, and various patterns may be formed. For example, the pattern may be formed in a grid pattern in which the light and shade between vertically and horizontally adjacent grids are clearly distinguished.

The pattern plate <NUM> is seated on the seating portion <NUM>. In this case, an inclination angle of the pattern plate <NUM> is preferably set to be <NUM> degrees or more and less than <NUM> degrees based on light that is reflected through a reflector <NUM> and incident. When the pattern plate <NUM> is disposed to be orthogonal to the incident light, there is a disadvantage in that each pattern formed on the pattern plate <NUM> has the same depth information (or height information) on the same surface, and accordingly, the pattern plate <NUM> is disposed to be inclined at a predetermined angle with respect to the incident light in design, thereby increasing a calibration effect. To this end, it is preferable to form an upper surface of the seating portion <NUM> on which the pattern plate <NUM> is seated as an inclined surface forming an inclination angle of <NUM> degrees or more and less than <NUM> degrees with respect to a longitudinal direction of the seating portion <NUM>.

The seating portion <NUM> includes an extension portion <NUM> (drawing added) formed to extend in the longitudinal direction together with the above-described inclined surface, and the extension portion <NUM> is rotatably supported by a holding portion <NUM> of the rotating unit <NUM> to be described below.

The pattern plate unit <NUM> further includes a first interlocking portion <NUM> formed integrally with the extension portion <NUM> formed at a lower end of the seating portion <NUM> to rotate in conjunction with rotation of the rotating unit <NUM> to be described below. As shown, the first interlocking portion <NUM> is preferably formed in the shape of a spur gear, but is not limited thereto, and various gears may, of course, be applied.

Meanwhile, the reflector unit <NUM> according to one embodiment of the present invention includes the reflector <NUM> for reflecting light emitted from the optical device of the oral scanner body <NUM> toward the above-described pattern plate <NUM> and a support portion <NUM> for supporting the reflector <NUM> to be inclined with respect to the oral scanner body <NUM>. Specifically, the reflector <NUM> may be formed of a rectangular mirror, but is not limited thereto, and mirrors of various shapes may, of course, be applied.

The support portion <NUM> includes a rectangular parallelepiped body and free ends <NUM> extending in the longitudinal direction from both sides of the body, and the reflector <NUM> is rotatably coupled to the free ends <NUM>. To this end, protrusions are formed on both sides of a rotation center of the reflector <NUM>, and the protrusions are coupled to openings formed in the free ends <NUM>.

In addition, the reflector unit <NUM> further includes a second interlocking portion <NUM> to rectilinearly reciprocate in conjunction with the rotation of the rotating unit <NUM> to be described below. Specifically, the second interlocking portion <NUM> is formed in the shape of a shaft formed to extend long in the longitudinal direction, and at its end, a rotation gear <NUM> formed to engage with a second coupling portion <NUM> of the rotating unit <NUM> to be described below is provided. As shown, the rotation gear <NUM> is preferably formed in the shape of a helical gear, but is not limited thereto, and various gears may, of course, be applied.

Preferably, as shown in <FIG>, holding portions <NUM> and <NUM> for supporting both sides of the second interlocking portion <NUM> so that the second interlocking portion <NUM> is rotatable may be provided on an inner circumferential surface of the body <NUM>, and more preferably, bearings for smooth rotation of the second interlocking portion <NUM> may be provided on inner circumferential surfaces of the holding portions <NUM> and <NUM>.

Preferably, the second interlocking portion <NUM> is formed to pass through the support portion <NUM>, a first screw thread <NUM> is formed on an outer circumferential surface of the second interlocking portion <NUM>, and a second screw thread <NUM> corresponding to the first screw thread <NUM> is formed on an inner circumferential surface of a through hole of the support portion <NUM>.

In this case, the reflector unit <NUM> according to one embodiment of the present invention may further include a rotation preventing member <NUM> so that the reflector <NUM> and the support portion <NUM> rectilinearly reciprocate along a longitudinal direction of the second interlocking portion <NUM>.

Specifically, as shown in <FIG>, the rotation preventing member <NUM> is formed on an upper surface of the holding portion <NUM> in a plate-like shape, and an end of the reflector <NUM> is seated on an upper surface of the rotation preventing member <NUM>. Accordingly, when the second interlocking portion <NUM> is rotated in conjunction with the rotating unit <NUM> to be described below, the rotation of the reflector <NUM> and the support portion <NUM> is prevented by the rotation preventing member <NUM>, and thus rotation is made between the first screw thread <NUM> and the second screw thread <NUM>, so that the reflector <NUM> and the support portion <NUM> rectilinearly move.

Preferably, a torsion spring may be disposed at the rotation center of the reflector <NUM> with respect to the support portion <NUM>, and in this case, the reflector <NUM> may move in close contact with the upper surface of the rotation preventing member <NUM>.

In this case, since, for the rotation preventing member <NUM>, any member is sufficient as long as it prevents the reflector <NUM> and the support portion <NUM> from being distorted, various shapes may, of course, be applied.

Meanwhile, as described above, since in the oral scanner of the stereo vision method, three-dimensional distance information is acquired based on two pieces of image data with a point in the oral cavity as the same focus, calibration of the oral scanner is frequently required for acquiring accurate 3D model data. In this case, when images of the pattern plate <NUM> are acquired at various angles and depths, calibration accuracy may be improved.

To this end, the calibration device <NUM> for an oral scanner according to one embodiment of the present invention further includes the rotating unit <NUM> that rotates in conjunction with the pattern plate unit <NUM> and the reflector unit <NUM> described above.

The rotating unit <NUM> is provided on the inner circumferential surface of the body <NUM> on the opposite side to the insertion portion <NUM>, and includes a rotating shaft <NUM>, a first coupling portion <NUM>, and the second coupling portion <NUM>. The rotating shaft <NUM> extends long to be perpendicular to the longitudinal direction of the oral scanner body <NUM>, and coupling portions engaged with the pattern plate unit <NUM> and the reflector unit <NUM> are provided on one side and the other side thereof.

Specifically, the first coupling portion <NUM> having a spur gear shape is disposed on one side of the rotating shaft <NUM> and is engaged with the first interlocking portion <NUM> of the pattern plate unit <NUM> described above. Accordingly, when the rotating shaft <NUM> is rotated, the first interlocking portion <NUM> engaged with the first coupling portion <NUM> is rotated, so that the pattern plate unit <NUM> rotates around a longitudinal axis.

Preferably, when the rotating shaft <NUM> rotates <NUM> degrees, the pattern plate unit <NUM> may rotate <NUM> degrees, but the rotation is not limited thereto.

Preferably, one side of the rotating shaft <NUM> may pass through the body <NUM> and extend to the outside of the body <NUM>, and at its end, a handle <NUM> for allowing a user to easily rotate the rotating shaft <NUM> may be formed. However, the rotation is not limited to manual rotation by the user as such, and automatic rotation by a motor or the like may be made.

Preferably, as shown in <FIG>, holding portions <NUM> and <NUM> for supporting both sides of the rotating shaft <NUM> so that the rotating shaft <NUM> is rotatable may be provided on the inner circumferential surface of the body <NUM>, and in this case, it is preferable that the holding portion <NUM> positioned closer to the pattern plate unit <NUM> supports the extension portion <NUM> of the seating portion <NUM> of the pattern plate unit <NUM> as well as the rotating shaft <NUM>. More preferably, bearings for smooth rotation of the rotating shaft <NUM> and the pattern plate unit <NUM> may be provided on inner circumferential surfaces of the holding portions <NUM> and <NUM>.

On the other side of the rotating shaft <NUM>, the second coupling portion <NUM> having a screw gear shape is disposed, and the second coupling portion <NUM> is engaged with the rotation gear <NUM> of the reflector unit <NUM> described above. When the rotating shaft <NUM> is rotated about its longitudinal axis, the rotation gear <NUM> engaged with the second coupling portion <NUM> is rotated about a longitudinal axis of the second interlocking portion <NUM> orthogonal to the longitudinal axis of the rotating shaft <NUM>. Accordingly, the support portion <NUM> coupled to the first screw thread <NUM> of the second interlocking portion <NUM> rectilinearly reciprocates along the longitudinal direction of the second interlocking portion <NUM>, and thus the support portion <NUM> and the reflector <NUM> coupled to the support portion <NUM> reciprocate based on the central axis of the oral scanner body <NUM>.

Preferably, when the rotating shaft <NUM> rotates <NUM> degrees, the reflector <NUM> may rectilinearly reciprocate by <NUM>, but is not limited thereto.

Meanwhile, since the pattern plate <NUM> rotates in place, when an inclination angle of the reflector <NUM> is not changed when the position of the reflector <NUM> with respect to the oral scanner body <NUM> is changed, the light emitted from the optical device may be reflected toward a place spaced apart from a center of the pattern plate <NUM>.

Specifically, as shown in <FIG>, when the center of the reflector <NUM> coincides with the center of the pattern plate <NUM>, the light emitted from the optical device reaches the center of the pattern plate <NUM> when the reflector <NUM> maintains an angle of <NUM> degrees.

However, when the reflector <NUM> approaches the optical device as shown in <FIG>, since the center of the reflector <NUM> does not coincide with the center of the pattern plate <NUM>, an incidence angle and reflection angle of the light emitted from the optical device should increase. Conversely, when the reflector <NUM> moves away from the optical device, the incidence angle and reflection angle of the light emitted from the optical device should decrease.

Therefore, the calibration device <NUM> for an oral scanner according to one embodiment of the present invention is characterized by adjusting the inclination angle of the reflector <NUM> through the rotation preventing member <NUM> when the reflector <NUM> rectilinearly reciprocates.

Specifically, as shown in <FIG>, it is preferable that the rotation preventing member <NUM> is formed of an inclined surface <NUM> whose thickness becomes thicker as the inclined surface <NUM> approaches the oral scanner body <NUM>.

For example, when the reflector <NUM> approaches the oral scanner body <NUM>, the reflector <NUM> moves along an upper side of the inclined surface <NUM>, so that the inclination angle with respect to the oral scanner body <NUM> decreases, and the incidence angle and reflection angle of light increase. In addition, when the reflector <NUM> moves away from the oral scanner body <NUM>, the reflector <NUM> moves along a lower side of the inclined surface <NUM>, so that the inclination angle with respect to the oral scanner body <NUM> increases, and the incidence angle and reflection angle of light decrease.

Preferably, the inclination angle of the inclined surface <NUM> may be designed so that the light reflected from the reflector <NUM> is directed toward the center of the pattern plate.

More preferably, at least one of one end and the other end of the inclined surface <NUM>, may be formed with a stepped portion <NUM> for restricting rectilinear movement of the reflector <NUM>.

As such, since in conjunction with the rotation of the rotating unit <NUM>, the pattern plate <NUM> rotates and the position of the reflector <NUM> with respect to the oral scanner body <NUM> is changed, images of the pattern plate <NUM> may be acquired at various angles and depths during calibration, and thus calibration accuracy may be improved.

Hereinafter, an operating process of the calibration device <NUM> for an oral scanner according to one embodiment of the present invention will be described in detail.

When a user grabs and rotates the handle <NUM> provided outside the body <NUM> of the casing <NUM>, the rotating shaft <NUM> integrally formed with the handle <NUM> rotates. When the first interlocking portion <NUM> engaged with the first coupling portion <NUM> disposed on one side of the rotating shaft <NUM> is rotated by the rotation of the rotating shaft <NUM>, the pattern plate unit <NUM> rotates around its longitudinal axis. At the same time, the second interlocking portion <NUM> engaged with the second coupling portion <NUM> disposed on the other side of the rotating shaft <NUM> rotates about the longitudinal axis. Accordingly, the support portion <NUM> coupled to the first screw thread <NUM> of the second interlocking portion <NUM> laterally reciprocates along the longitudinal axis of the second interlocking portion <NUM>, and thus the reflector <NUM> coupled to the support portion <NUM> rectilinearly reciprocate with respect to the oral scanner body <NUM>.

That is, since in conjunction with the rotation of the rotating unit <NUM>, the pattern plate <NUM> rotates and the reflector <NUM> rectilinearly reciprocates with respect to the oral scanner body <NUM>, images of the pattern plate <NUM> may be acquired at various angles and depths and thus calibration accuracy may be improved.

<FIG> is a perspective view of a calibration device for an oral scanner according to another embodiment of the present invention, <FIG> is a perspective view of an inner space of the calibration device for an oral scanner according to another embodiment of the present invention, <FIG> is an exploded perspective view of <FIG>, and <FIG> and <NUM> are cross-sectional views showing an operating process of the calibration device for an oral scanner according to another embodiment of the present invention.

Hereinafter, a calibration device <NUM>' for an oral scanner according to another embodiment (second embodiment) of the present invention will be described with reference to <FIG>. Parts overlapping with those of the first embodiment are omitted.

With reference to <FIG> and <FIG>, the calibration device <NUM>' for an oral scanner according to another embodiment of the present invention is a device for calibrating an optical device of an oral scanner, and includes a casing <NUM>', a rotating unit <NUM>', a pattern plate unit <NUM>', and a reflector unit <NUM>'.

The casing <NUM>' forms an outer circumferential surface of the calibration device <NUM>' for an oral scanner and includes a body <NUM>' for forming an inner space, an insertion portion <NUM>' that is formed on one side of an upper portion of the body <NUM>' and into which an oral scanner body <NUM> is inserted and supported, and first and second covers <NUM>' and <NUM>' formed to cover both sides of the body <NUM>'.

Meanwhile, the pattern plate unit <NUM>' according to another embodiment of the present invention is provided in the body <NUM>' so that a longitudinal axis thereof is positioned on an axis parallel to a central axis of the oral scanner body <NUM>. Accordingly, the pattern plate unit <NUM>' faces the optical device in the oral scanner body <NUM> through the reflector unit <NUM>' to be described below, and includes a pattern plate <NUM>' and a seating portion <NUM>'.

The seating portion <NUM>' includes an extension portion <NUM> (drawing added) formed to extend in the longitudinal direction together with an inclined surface, and the extension portion <NUM>' is rotatably supported by a holding portion <NUM>' of the rotating unit <NUM>' to be described below. More preferably, a support portion <NUM>' for supporting the seating portion <NUM>' may be formed to extend on an inner surface of the second cover <NUM>' so that the seating portion <NUM>' is supported by the support portion <NUM>'.

The pattern plate unit <NUM>' further includes an interlocking portion <NUM>' formed integrally with the extension portion <NUM>' formed at a lower end of the seating portion <NUM>' to rotate in conjunction with rotation of the rotating unit <NUM>' to be described below. As shown, the interlocking portion <NUM>' is preferably formed in the shape of a spur gear, but is not limited thereto, and various gears may, of course, be applied.

Meanwhile, as described above, since the pattern plate <NUM>' is positioned on an axis parallel to the central axis of the oral scanner body <NUM>, in order for the light emitted from the optical device to be incident on the pattern plate <NUM>', the light should be reflected <NUM> degrees through the reflector.

To this end, the reflector unit <NUM>' according to another embodiment of the present invention includes a plurality of reflectors for reflecting the light emitted from the optical device of the oral scanner body <NUM> toward the above-described pattern plate <NUM>' and a support portion <NUM>' for supporting the reflectors to be inclined with respect to the oral scanner body <NUM>.

Specifically, a first reflector <NUM>' is disposed at an angle of <NUM> degrees on the central axis of the oral scanner body <NUM>, and a second reflector <NUM>' is disposed at an angle of <NUM> degrees on a longitudinal axis of the pattern plate unit <NUM>'. That is, the first reflector <NUM>' and the second reflector <NUM>' are mirror symmetrical with respect to a plane positioned at the center of the central axis of the oral scanner body <NUM> and the longitudinal axis of the pattern plate unit <NUM>'. In this case, the light emitted from the optical device is reflected <NUM> degrees through the first reflector <NUM>' and the second reflector <NUM>', and is incident on the pattern plate <NUM>' provided above the second reflector <NUM>'. The reflectors may be formed of rectangular mirrors, but are not limited thereto, and mirrors of various shapes may, of course, be applied.

The support portion <NUM>' includes a rectangular parallelepiped body and a fixing portion extending from the body to support the first and second reflectors <NUM>' and <NUM>' at an angle.

In addition, the reflector unit <NUM>' further includes a guide portion <NUM>' to rectilinearly reciprocate in conjunction with the rotation of the rotating unit <NUM>' to be described below. Specifically, as will be described below, a rail <NUM>' extending in a direction parallel to the central axis of the oral scanner body <NUM> is formed on the inner surface of the second cover <NUM>' so that the reflector unit <NUM>' may rectilinearly reciprocate based on the oral scanner body <NUM> according to the rotation of the rotating unit <NUM>', and the guide portion <NUM>' is formed in a "C" shape below one side of the support portion <NUM>' to surround the rail <NUM>' described above.

Preferably, at least one of one end and the other end of the rail <NUM>' may be formed with a stepped portion for restricting rectilinear movement of the reflector unit <NUM>'.

As such, when the guide portion <NUM>' is coupled to the rail <NUM>', as will be described below, when the rotating unit <NUM>' rotates, the reflector unit <NUM>' is prevented from rotating and the moving direction of the guide unit <NUM>' may be guided.

Preferably, a through hole to which the rotating unit <NUM>' is coupled, which will be described below, is formed in the support portion <NUM>', and a screw thread <NUM>' is formed on an inner circumferential surface of the through hole.

Meanwhile, as described above, when images of the pattern plate <NUM>' are acquired at various angles and depths, calibration accuracy may be improved.

To this end, the calibration device <NUM>' for an oral scanner according to another embodiment of the present invention further includes the rotating unit <NUM>' that rotates in conjunction with the pattern plate unit <NUM>' and the reflector unit <NUM>' described above.

The rotating unit <NUM>' is provided on one side of an inner circumferential surface of the body <NUM>', and includes a rotating shaft <NUM>', a first coupling portion <NUM>', and a second coupling portion <NUM>'. The rotating shaft <NUM>' extends in a direction parallel to the central axis of the oral scanner body <NUM>, and the first coupling portion <NUM>' engaged with the pattern plate unit <NUM>' is provided on one side thereof.

Specifically, the first coupling portion <NUM>' having a spur gear shape is disposed on one side of the rotating shaft <NUM>' and is engaged with the interlocking portion <NUM>' of the pattern plate unit <NUM>' described above. Accordingly, when the rotating shaft <NUM>' is rotated, the interlocking portion <NUM>' engaged with the first coupling portion <NUM>' is rotated, so that the pattern plate unit <NUM>' rotates around a longitudinal axis.

Preferably, when the rotating shaft <NUM>' rotates <NUM> degrees, the pattern plate unit <NUM>' may rotate <NUM> degrees, but the rotation is not limited thereto.

Preferably, the other side of the rotating shaft <NUM>' may pass through the body <NUM>' and extend to the outside of the body <NUM>', and at its end, a handle <NUM>' for allowing a user to easily rotate the rotating shaft <NUM>' may be formed. However, the rotation is not limited to manual rotation by the user as such, and automatic rotation by a motor or the like may be made.

Preferably, as shown in <FIG>, holding portions <NUM>' and <NUM>' for supporting both sides of the rotating shaft <NUM>' so that the rotating shaft <NUM>' is rotatable may be provided on an inner surface of the cover, and in this case, it is preferable that the holding portion <NUM>' positioned closer to the pattern plate unit <NUM>' supports an axis of the seating portion <NUM>' of the pattern plate unit <NUM>' as well as the rotating shaft <NUM>'. More preferably, bearings for smooth rotation of the rotating shaft <NUM>' and the pattern plate unit <NUM>' may be provided at centers of the holding portions <NUM>' and <NUM>'.

On the other side of the rotating shaft <NUM>', the second coupling portion <NUM>' in the shape of a screw thread is formed. In addition, the second coupling portion <NUM>' is coupled to the through hole of the support portion <NUM>' of the reflector unit <NUM>' described above. Specifically, the screw thread <NUM>' corresponding to the second coupling portion <NUM>' is formed on the inner circumferential surface of the through hole, so that the rotating shaft <NUM>' and the reflector unit <NUM>' are rotatably coupled to each other.

In this case, when the rotating shaft <NUM>' is rotated about its longitudinal axis, a rotational force applied to the rotating shaft <NUM>' by a frictional force between the screw thread <NUM>' and the second coupling portion <NUM>' acts on the support portion <NUM>' of the reflector unit <NUM>, but as described above, since the guide portion <NUM>' formed on the support portion <NUM>' is coupled to the rail <NUM>' formed on the cover of the casing <NUM>', rotation of the support portion <NUM>' is restricted.

Accordingly, the support portion <NUM>' rectilinearly reciprocates along a longitudinal direction of the rail <NUM>', and thus the support portion <NUM>' and the reflectors supported by the support portion <NUM>' reciprocate based on the central axis of the oral scanner body <NUM>.

Preferably, when the rotating shaft <NUM>' rotates <NUM> degrees, the reflector unit <NUM>' may rectilinearly reciprocate by <NUM>, but is not limited thereto.

As shown in <FIG> and <FIG>, since in conjunction with the rotation of the rotating unit <NUM>', the pattern plate <NUM>' is rotated and the positions of the reflectors <NUM>' and <NUM>' with respect to the oral scanner body <NUM> are changed, images of the pattern plate <NUM>' may be acquired at various angles and depths during calibration, and thus calibration accuracy may be improved.

Hereinafter, an operating process of the calibration device <NUM>' for an oral scanner according to another embodiment of the present invention will be described in detail.

When a user grabs and rotates the handle <NUM>' provided outside the body <NUM>' of the casing <NUM>', the rotating shaft <NUM>' integrally formed with the handle <NUM>' rotates. When the interlocking portion <NUM>' engaged with the first coupling portion <NUM>' disposed on one side of the rotating shaft <NUM>' is rotated by the rotation of the rotating shaft <NUM>', the pattern plate unit <NUM>' rotates around its longitudinal axis. At the same time, a rotational force is applied to the reflector unit <NUM>' screw-coupled to the other side of the rotating shaft <NUM>', but the guide portion <NUM>' of the reflector unit <NUM>' is coupled to the rail <NUM>' formed on the cover of the casing <NUM>', so that the rotation of the reflector unit <NUM>' is restricted, and thus the reflector unit <NUM>' rectilinearly reciprocates along the rail <NUM>'. That is, the reflector unit <NUM>' rectilinearly reciprocates with respect to the oral scanner body <NUM>.

As such, since in conjunction with the rotation of the rotating unit <NUM>', the pattern plate <NUM>' rotates and the reflectors rectilinearly reciprocate with respect to the oral scanner body <NUM>, images of the pattern plate <NUM>' may be acquired at various angles and depths and thus calibration accuracy may be improved.

Claim 1:
A calibration device (<NUM>, <NUM>') for an oral scanner, comprising:
a casing (<NUM>, <NUM>') to which an oral scanner body (<NUM>) is coupleable to an open upper portion thereof;
a rotating unit (<NUM>, <NUM>') rotatably provided with respect to the casing (<NUM>, <NUM>');
a reflector unit (<NUM>, <NUM>') disposed on a central axis of an optical device in the oral scanner body (<NUM>); and
a pattern plate unit (<NUM>, <NUM>') facing the optical device through the reflector unit (<NUM>, <NUM>'),
wherein in conjunction with rotation of the rotating unit (<NUM>, <NUM>'), the pattern plate unit (<NUM>, <NUM>') rotates in place and the reflector unit (<NUM>, <NUM>') rectilinearly reciprocates with respect to the oral scanner body (<NUM>).