Scanning head and oral cavity digital impression instrument

Abstract

A scanning head for an oral digital impression instrument has a housing and a lens, the housing having a closed first end and an open second end, and a first side and an opposite second side extending between the first end and the second end and provided with a window portion; the lens is fastened at the inner wall of the shell and consists of a first volume of a truncated frustum part and a cuboid-shaped second volume connected with the first volume, the first volume takes the back surface of the lens as the top surface and a diagonal plane starting from the back surface as the peripheral surface and is provided with a bottom surface opposite to the top surface, and the diagonal plane forms an angle ranging from 0 to 90 degrees relative to the thickness direction of the lens; the second volume has the front face of the lens as a bottom face, the bottom face of the frustum portion as a top face, and has a thickness between the top face and the bottom face. Through beveling and grinding the non-effective surface of the lens, the edge thickness of the lens is reduced, and the inlet height of the scanning head is further reduced. The utility model further provides an oral cavity digital impression instrument with the scanning head.

Description

TECHNICAL FIELD

[0001] The utility model relates to a kind of scanning head for oral digital impression instrument.The utility model further relates to a kind of oral digital impression instrument with the aforementioned scanning head. BACKGROUND

[0002] Oral digital impression instrument is also called oral scanner, for collecting the digital image of patient's oral condition.Oral digital impression instrument has handpiece and scanning head provided with lens, wherein, scanning head is installed at the end of handpiece when in use.

[0003] The oral digital impression instrument commonly seen in the industry is operated by the operator to deflect by scanning head when in use Projection and shooting, to transmit the oral image of patient through the lens in scanning head Reflect to the handpiece of oral digital impression instrument, and then transmit to the computer coupled with oral digital impression instrument, so as to display the digital image of oral cavity in the display of computer.

[0004] For the need of light path propagation, lens will be provided in the scanning head of oral digital impression instrument, for reflecting the light emitted from the light emitting element usually arranged in handpiece.At present, the lens for reflection generally has uniform thickness, and its shape is generally rectangular, and chamfering is carried out at the corner of rectangle.

[0005] It has been found in the industry that the inlet height of the scanning head used by the existing oral digital impression instrument is large, and the shape of the inlet part of the shell of the scanning head is not smooth.These will reduce the comfort of patient during oral scanning.

[0006] In order to reduce the irritation caused by the scanning head of oral digital impression instrument in patient's oral cavity, the industry has made some attempts.

[0007] For example, a kind of oral scanning head of three-dimensional oral scanner is known from CN 221904162 U (publication date: October 29, 2024).By opening back side groove on the side of the back of the scanning end of the scanning head, the back side groove and the insertion surface are matched with each other, the volume of the scanning end is reduced, so as to limit the inlet height of the scanning head.

[0008] For example, a kind of end part of imaging device used in dental field is known from JP 2018-17323A (publication date: November 8, 2018).The edge of the end part can be chamfered, filed or other processed to reduce the possibility of sharp edge contacting patient's oral cavity and causing patient's pain or other discomfort.The lens provided in the end part can be selected as elliptical or bevel polygon according to the change of end part and end shape.

[0009] It is desirable in the industry to further improve the shape of the scanning head of the digital dental impression device to reduce the irritation of the patient's mouth by the scanning head during the oral scanning and to further improve the comfort of the patient when the scanning head enters the mouth. Utility model content

[0010] The utility model discloses a scanning head for digital dental impression device, the scanning head has improved shape and size, by the scanning head to the oral cavity of patient is scanned, can make patient have more comfortable experience.

[0011] In order to solve the above technical problems, according to the scanning head of the utility model has:

[0012] The shell is configured as hollow and has an internal space, the shell has: a closed first end and a second end opposite to the first end, and the scanning head has a first side extending between the first end and the second end and a second side opposite to the first side, wherein a window portion is formed on the first side,

[0013] The lens is fastened at the inner wall of the hollow shell, so that the light entering the internal space of the shell from the second end can be reflected at the effective surface of the lens and exit from the window portion provided on the first side, leaving the internal space of the shell, wherein the lens is chamfered, so that the lens is composed of a first volume and a second volume connected to the first volume,

[0014] Wherein the first volume is configured as the shape of a truncated frustum, the truncated frustum has the back surface of the lens as the top surface, the chamfered surface from the back surface as the outer peripheral surface, and the truncated frustum has the bottom surface opposite to the top surface,

[0015] Wherein the chamfered surface of the lens is chamfered at a chamfered surface angle with respect to the thickness direction of the lens, and

[0016] Wherein the second volume is configured as the shape of a cuboid, the cuboid has the front surface of the lens as the bottom surface, the bottom surface of the truncated frustum as the top surface, and the cuboid has the thickness between the bottom surface and the top surface.

[0017] According to the scanning head of the utility model, the non-effective surface of the lens is chamfered and ground from the back surface of the lens at a chamfered surface angle, compared with the lens prototype which is substantially cuboid, the edge thickness of the ground lens is reduced, and the size of the part of the scanning head shell matched with the lens, i.e. the part for fastening the lens, is reduced, so as to reduce the entry height of the entry part of the scanning head into the patient's mouth, and reduce the discomfort of the patient during the oral scanning.

[0018] It should be noted that the part of the lens which is chamfered comprises a part of the back and of the side of the original cuboid, the chamfering not being directly machined to the front of the lens. In other words, the lens is not chamfered over its entire thickness, but only over a part of its thickness, so as to avoid influencing the reflection effect of the lens and thus the propagation of the light path in the digital dental impression apparatus in which the scanning head is applied.

[0019] In a preferred embodiment of the application, when the chamfer angle is in the range of 55° to 65°, the lens edge thickness can be reduced without influencing the light path, and the corresponding part of the housing of the scanning head can be shaped, for example, beveled, in a suitable shape and size.

[0020] In a particularly preferred embodiment of the application, the chamfer angle is 60°, which value allows to reduce the lens edge thickness as much as possible while meeting the requirements of the machining process.

[0021] In another preferred embodiment of the application, the chamfer angles of the chamfered surfaces of the lens relative to the thickness direction of the lens are identical. This simplifies the machining of the lens and can simplify the structural design of the part of the housing of the scanning head which cooperates with the lens, and facilitates the manufacture of the housing, for example, by being integrally machined by molding.

[0022] In an embodiment of the application, the lens is fastened with its back by means of an adhesive, for example, glue, to the inner wall of the housing of the scanning head, which housing is made of plastic, for example. This fastening facilitates the installation of the lens which has been subjected to chamfering.

[0023] In a non-limiting embodiment of the application, the lens is fastened substantially by means of an adhesive to the inner wall of the top side of the housing of the scanning head, i.e., to the inner surface of the top side of the hollow cylindrical housing, the top side of the housing extending here obliquely to the first side opposite the second side provided with the window portion. In particular, the top side of the housing extends here at an acute angle to the first side of the housing.

[0024] As already explained above, the chamfered lens has a reduced edge thickness, which allows the configuration of the top side of the housing extending obliquely to the first side of the housing, in particular the small edge thickness of the lens, to be provided with a small oblique angle of the top side of the housing to the first side of the housing. This allows the maximum height of the inlet portion of the scanning head to be small at the same inlet depth, and reduces the likelihood of the top end of the top side of the scanning head, i.e., the end remote from the first side, scratching the inside of the patient's mouth during the oral scan.

[0025] Herein, the entry height of the entry portion of the scanning head is defined as the vertical distance between the first side and the second side of the housing of the scanning head.

[0026] In the case of an entry depth of 40.00 mm, the entry height of the scanning head according to the utility model is in the range of 15.8 to 20.55 mm.

[0027] In a non-limiting embodiment of the utility model, a groove is provided at the inner wall of the housing of the scanning head, and the groove is clamped between the first boss portion and the second boss portion. The groove is used to accommodate the adhesive for fastening the lens, so that the lens is fastened in the housing of the scanning head by means of the adhesive with its back surface, and the back surface of the lens rests on the first boss portion and the second boss portion.

[0028] The provision of the groove in the housing of the scanning head enables the application range of the adhesive for fastening the lens to be controlled, avoiding the thickness of the adhesive layer being too thick, and the provision of the boss portions on both sides of the groove facilitates the positioning of the lens when the back surface of the lens is adhesively fastened, and controls the range of the application of the adhesive to the back surface of the lens. The first boss portion and the second boss portion are, for example, implemented as elongated ribs that protrude towards the interior space of the housing with respect to the aforementioned groove, or the ribs protrude towards the interior space with respect to the inner surface of the housing.

[0029] Further, in a non-limiting embodiment of the utility model, the lens after the oblique grinding treatment is chamfered, specifically, the second volume of the lens is chamfered. Herein, the second volume of the lens after the oblique grinding is approximately a cuboid shape, but its thickness is thin, so it can also be described as approximately a rectangular shape. By chamfering the eight corners of the second volume of the approximately cuboid shape, the corners of the second volume of the lens are rounded, facilitating the operation when the lens is fastened, avoiding the risk that may occur during the process of fastening the lens due to the sharp corners of the lens.

[0030] Further, by combining the above-mentioned chamfering of the corners of the lens and the oblique cutting of the non-effective surface, the occurrence of right angles in the structure of the lens itself is reduced, so that the corresponding part of the housing of the scanning head for fastening the lens, especially the corresponding part of the end of the top side of the scanning head, can be more smoothly shaped, without having to conform to the right angle structure of the corners of the lens, reducing the process difficulty when producing the housing of the scanning head, and improving the production efficiency.

[0031] Specifically, in the case where the lens of the scan head according to the present application has the above-mentioned beveling and chamfering configuration, the first corner portion on both sides of the top end of the housing of the scan head is chamfered. The first corner portion is specifically the corner portion formed by the top side, the first side of the housing of the scan head and the two side portions of the housing of the scan head. The aforementioned two side portions are the two side portions between the first side and the second side in the circumferential direction of the scan head, i.e. the third side and the fourth side.

[0032] When viewed from the first side of the scan head, the first corner portion between the first side and the top side is chamfered with a radius ranging from greater than or equal to 4.25 mm to less than 6 mm.

[0033] In a preferred embodiment of the present application, the radius adopted for chamfering the first corner portion is 5 mm.

[0034] In an embodiment of the present application, the housing of the scan head is configured such that the lens fastened at the inner wall of the top side of the housing of the scan head abuts against the inner surface of the housing of the scan head with its side edge portion, in particular the side edge of the second volume of the substantially cuboid configuration. Thus, the lens is fastened at the inner surface of the housing of the scan head by means of, for example, an adhesive and cooperates with the shape of the housing of the scan head.

[0035] The present application also provides an oral digital impression instrument having the scan head designed and configured according to any of the above-mentioned solutions and further having a handpiece, the scan head being mounted at the end of the handpiece with its open second end portion.

[0036] The entrance portion of the oral digital impression instrument according to the present application is relatively rounded in shape and has a relatively low height, which causes less stimulation to the inside of the patient's mouth and improves the comfort of the patient when using the instrument to collect images inside the mouth.

[0037] Additional features and advantages are described in, and will be apparent from, the following DETAILED DESCRIPTION and the DRAWS, which are included herewith. BRIEF DESCRIPTION OF DRAWINGS

[0038] With reference to the above objects, the technical features of the present application are clearly described in the following claims, and the advantages thereof are apparent from the following detailed description with reference to the accompanying drawings, which show by way of example preferred embodiments of the present application, without limiting the scope of the inventive concept.

[0039] Figure 1 A lens in a scan head according to an embodiment of the present application is shown.

[0040] Figure 2 A top view of a scan head according to an embodiment of the present application is shown;

[0041] Figure 3 A side view of the scan head shown is shown; Figure 2 A cross-sectional view of a first end portion of the scan head shown is shown;

[0042] Figure 4 A rear view of the first end portion of the scan head shown is shown; and Figure 2 A front view of the first end portion of the scan head shown is shown.

[0043] Figure 5 A front view of the first end portion of the scan head shown is shown. Figure 2 A front view of the first end portion of the scan head shown is shown.

[0044] Figure 6 A front view of the first end portion of the scan head shown is shown. Figure 2 A front view of the first end portion of the scan head shown is shown.

[0045] List of Reference Signs

[0046] C1 first corner

[0047] C2 second corner

[0048] E1 first end

[0049] E2 second end

[0050] F10 window portion

[0051] H thickness direction

[0052] Hi entrance height

[0053] Himin minimum entrance height

[0054] Himax maximum entrance height

[0055] Li entrance depth

[0056] M10 lens

[0057] P1 first boss portion

[0058] P2 second boss portion

[0059] P3 third boss portion

[0060] R (rounded) radius

[0061] Rmin minimum radius

[0062] Rmax maximum radius

[0063] R1 recess

[0064] R2 recess

[0065] R3 groove

[0066] S11-S18 (lens) cut face

[0067] S21 (lens) back face

[0068] S22 (lens) front face

[0069] S31 (housing) first side

[0070] S32 (housing) second side

[0071] S33 (housing) top side

[0072] S34 (housing) third side

[0073] S35 (housing) fourth side

[0074] S41 abutment

[0075] S42 abutment

[0076] S50 scan head

[0077] S60 (scan head) housing

[0078] S61 (housing) inner wall

[0079] T10 transition

[0080] T20 thickness

[0081] a bevel angle

[0082] V1 first volume

[0083] V2 second volume DETAILED DESCRIPTION

[0084] Reference will now be made in detail to various embodiments of the present application, examples of which are illustrated in the accompanying drawings and described below. While the present application will be described in conjunction with the exemplary embodiments, it will be understood that the present application is not limited to the exemplary embodiments. Rather, the present application is intended to cover all alternatives, modifications, equivalents and other embodiments that can be included within the spirit and scope of the present application as defined by the appended claims. For the purposes of the present application, the terms "upper", "lower", "inner" and "outer" are used to describe the relative location of features of the exemplary embodiments shown in the figures, unless otherwise indicated.

[0085] Figure 1 A front view of the lens M10 is shown in (a) of FIG. 10. Figure 1 A front view of the lens M10 is shown in (a) of FIG. 10. Figure 1 A rear view of the lens M10 is shown in (b) of FIG. 10. Figure 1 A side view of the lens M10 is shown in (c) of FIG. 10.

[0086] The lens M10 is processed from a prototype of a substantially rectangular parallelepiped, and the corner portions of the parallelepiped are chamfered. Further, as can be seen in (b) and (c) of FIG. 10, the chamfered parallelepiped is subjected to an inclined surface grinding process from the rear surface S21 of the lens M10. Figure 1 As can be seen in (b) and (c) of FIG. 10, the chamfered parallelepiped is subjected to an inclined surface grinding process from the rear surface S21 of the lens M10. As a result, the lens M10 is formed in a substantially truncated frustoconical shape as viewed from the rear surface S21, and eight inclined surfaces S11, S12, S13, S14, S15, S16, S17, S18 are formed from the rear surface S21 of the lens. Of these, the inclined surfaces S11, S13, S15, S17 are located at the chamfered corner portions of the lens M10, and the inclined surfaces S12, S14, S16, S18 are located at the edge portions of the lens M10. Here, the non-effective surface of the lens M10 includes the rear surface S21 of the lens M10 and the side surfaces of the above-described parallelepiped before the inclined surface grinding process.

[0087] The angle of the inclined surface of the lens M10 subjected to the inclined surface grinding process from the rear surface S21 is defined as the angle of the inclined surface with respect to the thickness direction H of the lens M10 as viewed in the side view of the lens M10. As shown in (c) of FIG. 10, the angle of the inclined surface S15 of the lens M10 with respect to the thickness direction H of the lens M10 is the angle a. Here, the angle a is 60°. Further, in this embodiment, the angles of the other inclined surfaces S11 to S14 and S16 to S18, for example, the angle of the inclined surface S13 with respect to the thickness direction H of the lens M10 are also 60°. In other words, in this embodiment, the angle of the inclined surface of the lens M10 subjected to the inclined surface grinding process is the same for each side surface of the lens M10. Figure 1 As shown in (c) of FIG. 10, the angle of the inclined surface S15 of the lens M10 with respect to the thickness direction H of the lens M10 is the angle a. Here, the angle a is 60°. Further, in this embodiment, the angles of the other inclined surfaces S11 to S14 and S16 to S18, for example, the angle of the inclined surface S13 with respect to the thickness direction H of the lens M10 are also 60°. In other words, in this embodiment, the angle of the inclined surface of the lens M10 subjected to the inclined surface grinding process is the same for each side surface of the lens M10.

[0088] Further, as shown in (b) of FIG. 10, the lens M10 is formed in a substantially truncated frustoconical shape as viewed from the front surface S22. Figure 1As can be seen in (c), the bevels S11 to S18, which can be observed in (c), do not extend directly to the front side S22 of the lens M10, but rather terminate at a distance from the front side S22 of the lens M10. That is, the beveling process of the lens M10 from the back side S21 does not directly process to the front side S22 of the lens M10, but rather terminates at a distance from the front side S22. Thereby, the lens M10 is composed of a first volume VI and a second volume V2. The first volume VI is a substantially truncated frustum shaped volume with the back side S21 of the lens M as its top side and surrounded by the bevels S11 to S18. The second volume V2 is a volume with its top side being the bottom side of the first volume VI and with this bottom side as its top side. As Figure 1 As can be seen in (c), the second volume V2 is formed as a substantially cuboid volume with chamfered corners and has a substantially uniform thickness T20, which is the edge thickness of the lens M10 after the beveling process. The edge thickness is substantially smaller than the vertical distance from the front side S22 to the back side S21 of the lens M10, thereby achieving a reduction of the edge thickness of the substantially cuboid configured lens M10 and facilitating a reduction of the entrance height of the scanning head of the dental digital impression device to which the lens M10 is applied. Furthermore, the chamfering process of the corners of the substantially rectangular shape of the lens M10, in particular of the corners of the second volume V2 of the substantially cuboid configuration, also facilitates a reduction of the difficulty of molding the corresponding part of the housing of the scanning head in which the lens M10 is mounted. This will be explained in more detail below in connection with the figures.

[0089] Next, reference is made to Figure 2 and Figure 3 wherein a scanning head S50 for a dental digital impression device is shown, in which the lens M10 for reflection is mounted.

[0090] As can be seen in Figure 2 and Figure 3 the scanning head S50 has a housing S60. The housing S60 is made in one piece by a process such as injection molding and is configured as a hollow cylinder. The housing S60 thereby has an inner surface and an outer surface and has a certain thickness. The housing S60 is configured with a closed first end E1 and an open second end E2. The diameter of the substantially cylindrical housing S60 decreases gradually from the second end E2 to the first end E1.

[0091] The housing S60 has a first side S31, a second side S32 opposite the first side S31 and a top side S33. As can be seen in Figure 2 and Figure 3 the first end E1 terminates with an inclined platform, which is formed on the top side S33.

[0092] A window portion F10 is formed on the first side S31 of the housing S60. A lens M10 is mounted on the inner wall S61 of the housing S60, near the first end portion E1, opposite the window portion F10, so that light from the light emitting element of the digital impression machine is refracted by the lens M10 and exits through the window portion F10.

[0093] Since a portion of the scanning head S50, starting from the first end portion E1, extends into the patient's mouth when the digital impression machine is in use, the size and shape of this portion of the housing S60 of the scanning head S50 directly affect the patient's experience when the oral cavity is scanned.

[0094] Specifically, the scanning head S50 is configured such that, when the scanning head S50 is mounted at the end of the corresponding handpiece of the digital impression machine via the second end portion E2, the metal carrier structure of the handpiece can extend into the hollow interior space of the housing S60 through the opening of the second end portion E2. Thus, light from the light emitting element in the handpiece can propagate through the metal carrier structure to the lens M10 provided near the first end portion E1 of the scanning head S50 via the interior space of the housing S60. Further, the light is reflected at the lens M10 and then passes through the window portion F10 on the first side S31 of the housing S60 to the patient's oral cavity and returns to the handpiece of the digital impression machine via the above route, thereby achieving scanning and imaging of the patient's oral cavity.

[0095] Therefore, the lens M10 is an important component of the scanning head S50 for achieving the image transmission function in the patient's mouth, and the projection and illumination window of the scanning head S50 will have a decisive effect on the lens M10. Further, due to the fastening method of the lens M10 to be explained below, the shape and thickness of the lens M10 will directly affect the size and height of the support structure portion of the scanning head housing S60.

[0096] The mounting of the lens M10 in the scanning head S50 is explained below.

[0097] Figure 3 Part (b) of FIG. 8 shows a cross section B-B of the scanning head S50 taken along the line B-B near the first end portion E1 of the scanning head S50. Figure 3 Part (a) of FIG. 8 shows a cross section B-B of the scanning head S50 taken along the line B-B near the first end portion E1 of the scanning head S50.

[0098] As shown in FIG. 8, the lens M10 is mounted on the inner wall S61 of the housing S60 of the scanning head S50, near the first end portion E1 of the scanning head S50. Figure 3As seen in section (b), the lens M10 is fastened to the inner wall S61 of the housing S60 of the scanning head S50 as described above, and faces the window F10 located on the first side S31 of the housing S60. In this embodiment, the lens M10 is fastened to the inner wall S61 of the scanning head S50 only with its back surface S21 by means of adhesive. It should be noted that the adhesive applied to the back surface S21 of the lens M10 should meet the corresponding adhesive layer thickness requirements, and should not be excessive. Furthermore, as will be explained further below, the back surface S21 is not covered with adhesive on its entire surface.

[0099] Furthermore, recesses R1 and R2 are formed on both sides of the portion of the inner wall S61 used for securing the lens M10 on the inner surface of the housing S60. The recesses R1 and R2 extend along the longitudinal direction of the scanning head S50. The secured lens M10 extends over the recesses R1 and R2 without contacting their surfaces. From the recesses R1 and R2 outwards, i.e., away from the top side S33, the lens M10, with its side portion, specifically the generally rectangular side portion of the second volume V2, abuts against the abutment portions S41 and S42 on the inner surface of the housing S60, thereby causing the lens M10 to engage with the housing S60 in a fitting manner according to its side shape. The aforementioned abutment portions S41 and S42 are located on the inner surfaces of the two sides between the first side S31 and the second side S32 of the housing S60, i.e., the third side S34 and the fourth side S35.

[0100] Thus, the abutment portions S41 and S42 located outside the recesses R1 and R2 enable the lens M10 to be installed, positioned, and guided in the housing S60 of the scanning head S50, especially in a section orthogonal to the longitudinal or extending direction of the housing S60.

[0101] Figure 4 The image shows a portion of the longitudinal central section of the scanning head S50, specifically a part near the first end E1.

[0102] like Figure 4 As can be seen, a groove R3 is recessed inward along the thickness direction of the housing S60 at the inner surface of the first end E1 of the housing S60. This groove R3 is sandwiched between the first boss P1 and the second boss P2. The adhesive used to fasten the lens M10 is applied to this groove R3. Further, as... Figure 4As shown, the length of the recess R3 is less than the length of the back surface S21 of the lens M10, so that the back surface S21 of the lens M10, except for a part contacting the adhesive applied in the recess R3, will rest on the first and second boss portions P1 and P2 located on both sides of the recess R3, and the surfaces of the first and second boss portions P1 and P2 are not applied with adhesive. The first and second boss portions P1 and P2 thus help the lens M10 to be positioned in the installation aspect, facilitating the installation of the lens M10 on the inner surface of the top side S33 of the obliquely arranged first end portion E1, and in combination with the recess R3, limiting the range of application of the adhesive for fastening the lens M10.

[0103] In Figure 4 It can also be seen in the figure that the two sides of the second boss portion P2 are respectively delimited by the recess R3 and the recessed portion R2 described above. On the other side of the recessed portion R2, i.e. the abutting portion S42 described above, one side of the second volume V2 of the lens M10 fastened inside the scanning head S50 abuts and is in a form fit with the abutting portion S42. The position of the recessed portion R2 is approximately on the corresponding inner surface of the first corner C1 formed by the junction transition of the top side S33 and the first side S31 of the housing S60 of the scanning head. The above-mentioned transition of the housing S60 of the scanning head S50 between the first side S31 and the top side S33 is configured as two first corners C1 that are rounded. Similarly, the transition of the housing S60 between the second side S32 and the top side S33 is configured as a second corner C2 that is rounded. The first corner C1 is farther away from the second end portion E2 than the second corner C2, and thus first extends into the patient's mouth when the scanning head S50 is in use.

[0104] As shown in the figure, the window portion F10 is recessed towards the interior space of the scanning head S50 with respect to the first side S31 of the scanning head S50, and there is also an inclined transition T10 on the side away from the first end portion E1 to transition to the first side S31, while most of the side edges of the window portion F10 are horizontally extended in the plane of the figure. Figure 4 As shown in the figure, the window portion F10 is recessed towards the interior space of the scanning head S50 with respect to the first side S31 of the scanning head S50, and there is also an inclined transition T10 on the side away from the first end portion E1 to transition to the first side S31, while most of the side edges of the window portion F10 are horizontally extended in the plane of the figure.

[0105] It can be noted that the top side S33 of the first end portion E1 of the scanning head S50 is not arranged perpendicularly with respect to the first side S31 but is arranged obliquely. Therefore, the lens M10 fastened at the inner surface of the top side S33 of the scanning head S50 and the window portion F10 opened at the first side S31 are mutually angularly obliquely opposite. In this embodiment, according to the imaging needs of the corresponding oral digital impression device, the corresponding sizes of the lens M10 and the window portion F10 and their relative positional relationship meet the size requirements of the projection and illumination window of 16mmx14mm.

[0106] As Figure 3 and Figure 4As can be seen, due to the beveling of the lens M10 from the back side S21, the first volume V1 is reduced compared to the initial cuboid configuration, and as has been explained above, the edge thickness T20 of the lens M10 is reduced, so that the top side S33 of the housing S60 for fastening the lens M10 can be arranged at a smaller angle, and in turn the distance between the first side S31 and the second side S32 at the first end E1 of the scan head S50 is reduced, thereby achieving a reduction of the entry height Hi of the scan head S50. In the following, this will be further explained in connection with Figure 5 The entry height Hi is further explained.

[0107] Turning to Figure 5 The depth of the scan head S50 into the patient's mouth, i.e. the entry depth Li, is calculated from the most forward end of the first end E1 of the scan head S50, i.e. the most forward end of the first corner C1, when in use. The entry height Hi of the scan head S50 is the distance between the first side S31 and the second side S32. In the case of an entry depth Li of 40.00 mm, the minimum value of the entry height Hi of the scan head S50 is 15.80 mm, while the maximum value of the entry height Hi is 20.55 mm. The minimum entry height Himin of the scan head S50 is the perpendicular distance from the lowest point of the second side S32 to the first side S31 when the scan head S50 is viewed from the side. In the shown embodiment, the lowest point of the second side S32 is located at the other end point of the perpendicular line with respect to the first side S31 at the window portion F10, after which the entry height Hi of the scan head S50 gradually increases away from the first end E1 of the scan head S50, and the maximum entry height Himax occurs at a distance of 40.00 mm from the apex of the first corner C1. The minimum entry height Himin of the scan head S50 is further reduced by the beveling of the lens M10, which reduces the entry difficulty of the scan head S50 into the patient's mouth, and also reduces the possibility of the second corner C2 and the second side S32 scraping the gums or other parts of the patient's mouth when scanning with the scan head S50.

[0108] Further, by the chamfering of the corners of the lens M10, in particular the corners of the second volume V2 which is substantially cuboid, the rounding of the first end E1 of the molded housing S60 of the scan head S50 and the corresponding parts of the above-mentioned corners of the lens M10 is also improved. This will be further explained in the following with reference to Figure 6 This is further explained.

[0109] Figure 6 A front view showing a part of the first end E1 of the scan head S50 as viewed from the first side S31 of the scan head S50 is shown.

[0110] As Figure 6As can be seen, the top side of the first end E1 of the scan head S50, i.e. the two first corners C1 on the first side S31, are rounded. The two first corners C1 are rounded with a radius R with respect to the window portion F10 provided on the first side S31.

[0111] In the illustrated embodiment, the radius R for rounding the first corners C1 is 5 mm. In other embodiments, the radius R for rounding the first corners C1 can be other values within the range of 0 to 90°, but not including the endpoints, for example, the radius R for rounding the first corners C1 can be 55 to 65°. Figure 6 The positions of the minimum radius Rmin and the maximum radius Rmax for rounding the first corners C1 are also shown in FIG. 6. The maximum radius Rmax for rounding the first corners C1 of the housing S60 of the scan head S50 is 6 mm, and the minimum radius Rmin for rounding the first corners C1 is 4.25 mm when injection molded. The two first corners C1 of the scan head S50 are the portions of the scan head S50 that are likely to contact the oral mucosa and the gums of the patient when scanning the patient’s oral cavity.

[0112] The above-mentioned entry height Hi, in particular the minimum entry height Himin, of the scan head S50 is reduced, and the above-mentioned radius range for rounding the first corners C1 of the first end E1 of the housing S60 of the scan head S50 achieves a more rounded corner of the housing of the scan head. This helps to reduce the effect of the movement of the scan head S50 in the patient’s mouth on the sensitive oral nerves of the patient. Further, the above-mentioned radius for rounding the first corners C1 makes the first corners C1 more rounded, and also reduces the difficulty of molding the one-piece housing S60 of the scan head S50, achieves a smooth transition of the curved surface, and achieves the effect that the entry portion of the scan head S50 has no sharp edges and no abrupt structures in structure on the basis of satisfying the process of injection molding. This also helps to improve the manufacturing efficiency of the housing S60 of the scan head S50.

[0113] [Other embodiments]

[0114] In other embodiments not shown, according to the requirements for the entry height of the scan head S50 and the matching needs of the housing S60 of the scan head S50, the bevel angle a of the bevel surface of the lens M10 with respect to the thickness direction H of the lens M10 can be other values within the range of 0 to 90°, but not including the endpoints, for example, the bevel angle a can be 55 to 65°.

[0115] The oral cavity digital impression instrument according to the utility model improves the tactile sensation of the patient when the molding structure part as the carrier of the lens directly contacts the oral cavity of the patient, and reduces the height size of the lens and the structure part of the molding scanning head shell through beveling and grinding of the non-effective area of the lens in the thickness direction, thereby reducing the entrance height of the scanning head into the mouth of the patient, and optimizing the structure of the molding structure part.

[0116] The combination of the beveling and grinding and the rounding of the lens can be applied not only to the field of the oral cavity digital impression instrument, especially the scanning head matched with the wireless oral cavity digital impression instrument handheld part, but also to any shooting and projection equipment with a lens, such as an endoscope, a projector, a camera, a VR glasses and the like.

[0117] In the scope of the utility model, each embodiment can be freely combined, or each embodiment can be appropriately deformed or omitted.

Claims

1. A scanning head (S50) for a digital dental impression device, characterized in that, the scanning head (S50) has a housing (S60) configured as a hollow body, the housing (S60) has a closed first end (E1) and an open second end (E2) opposite to the first end (E1), and the housing (S60) has a first side (S31) extending between the first end (E1) and the second end (E2) and a second side (S32) opposite to the first side (S31), wherein a window portion (F10) is formed on the first side (S31), the scanning head (S50) further has a lens (M10) fastened at an inner wall (S61) of the housing (S60) so that light rays entering an inner space of the housing (S60) from the second end (E2) can be reflected at an effective surface of the lens (M10) to exit the inner space of the housing (S60) from the window portion (F10), wherein the lens (M10) is composed of a first volume (V1) and a second volume (V2) connected to the first volume (V1), wherein the first volume (V1) is formed in a shape of a truncated frustum, the truncated frustum has a back surface (S21) as a top surface, a bevel surface (S11-S18) from the back surface (S21) as an outer peripheral surface, and a bottom surface opposite to the top surface, wherein the bevel surface (S11-S18) of the lens (M10) has a bevel surface angle (α) with respect to a thickness direction of the lens (M10), the bevel surface angle (α) ranges from 0 to 90°, and wherein the second volume (V2) is formed in a shape of a cuboid, the cuboid has a front surface (S22) as a bottom surface, a top surface of the truncated frustum as a top surface, and a thickness (T20) between the top surface and the bottom surface of the cuboid.

2. The scanning head (S50) according to claim 1, characterized in that The bevel surface angle (α) is 55-65°.

3. The scanning head (S50) according to claim 1 or 2, characterized in that The lens (M10) is fastened at the back surface (S21) to the inner wall (S61) of the housing (S60) of the scanning head (S50) by means of an adhesive.

4. The scanning head (S50) according to claim 3, characterized in that The inner wall (S61) of the housing (S60) is provided with a recess (R3) clamped between a first boss portion (P1) and a second boss portion (P2), the recess (R3) is used to accommodate the adhesive to fasten the lens (M10) at the back surface (S21) in the housing (S60) of the scanning head (S50), and the back surface (S21) is rested on the first boss portion (P1) and the second boss portion (P2).

5. The scanning head (S50) according to claim 4, characterized in that A top side (S33) of the housing (S60) extends obliquely from the first side (S31) to the second side (S32) with respect to the first side (S31), and the lens (M10) is fastened at an inner surface of the top side (S33) of the housing (S60).

6. The scanning head (S50) according to claim 1 or 2, characterized in that A vertical distance between the first side (S31) and the second side (S32) ranges from 15.8 to 20.55 mm when an entry depth (Li) is 40.00 mm.

7. The scanning head (S50) according to claim 1 or 2, characterized in that The front side (S22) of the lens (M10) is designed and configured as a rectangle with rounded corners.

8. The scanning head (S50) as claimed in claim 7, characterized in that A first corner (C1) between the first side (S31) and a top side (S33) of the housing (S60) is rounded with a radius (R) ranging from 4.25 to 6 mm.

9. The scanning head (S50) as claimed in claim 1 or 2, characterized in that The lens (M10) abuts against the abutting portions on the inner surfaces of the first side (S31) and the second side (S32), respectively, with its side edges.

10. An oral digital impression device, characterized by A handheld piece and a scanning head (S50) as claimed in any one of claims 1 to 9, wherein the scanning head (S50) is mounted at an end of the handheld piece with its open second end (E2).

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