Scanning head and intraoral digital impression device

Abstract

A scanning head for an intraoral digital impression device, the scanning head having a housing and a lens. The housing has a closed first end, an open second end, and a first side provided with a window portion and an opposite second side which extend between the first end and the second end. The lens is fastened at the inner wall of the housing and is composed of a first volume in the shape of a truncated pyramid and a second volume in the shape of an adjoining cuboid, wherein the first volume uses a back surface of the lens as a top surface, uses as an outer peripheral surface beveled surfaces extending from the back surface, and has a bottom surface opposite the top surface, and the beveled surfaces are at an angle ranging from 0° to 90° relative to the direction of thickness of the lens; and the second volume uses a front surface of the lens as a bottom surface, uses a bottom surface of the truncated pyramid as a top surface, and has a thickness between the top surface and the bottom surface. By means of beveling and grinding a non-effective surface of the lens, the thickness of the edge of the lens is reduced, thereby reducing the entrance height of the scanning head. Further provided is an intraoral digital impression device having the scanning head.

Description

Scanning head and digital impression device for oral cavity Technical Field

[0001] This disclosure relates to a scanning head for a digital dental impression apparatus. This disclosure also relates to a digital dental impression apparatus having the aforementioned scanning head. Background Technology

[0002] A digital dental impression device, also known as a dental scanner, is used to acquire digital images of a patient's oral cavity. A digital dental impression device consists of a handheld component and a scanning head equipped with lenses, the scanning head being mounted at the end of the handheld component during use.

[0003] In common dental digital impression instruments, the operator uses a handheld device to project and capture images through a scanning head. The images of the patient's mouth are reflected by a lens inside the scanning head and transmitted to the handheld device of the dental digital impression instrument, and then transmitted to a computer connected to the dental digital impression instrument so that the digital images of the mouth can be displayed on the computer monitor.

[0004] For the purpose of light propagation, a lens is provided in the scanning head of a digital dental impression machine to reflect the light emitted from the light-emitting element, which is usually located in the handheld component. Currently, this reflective lens generally has a uniform thickness and is roughly rectangular in shape, with chamfered corners.

[0005] Industry experts have observed that existing digital impression machines use scanning heads with relatively large entry heights and non-rounded shapes in the entry portion of the scanning head housing. These factors reduce patient comfort during intraoral scanning.

[0006] To reduce the irritation caused by the scanning head of a digital impression device in the patient's mouth, the industry has made some attempts.

[0007] For example, a three-dimensional oral scanner head is known from CN 221904162 U (publication date: October 29, 2024). By creating a back-side groove on the side of the scanning end of the scanning head away from the insertion surface, the insertion surface and the back-side groove cooperate with each other, reducing the volume of the scanning end and thus limiting the entrance height of the scanning head.

[0008] For example, an end component of an imaging device used in the dental field is known from JP 2018-17323A (publication date: November 8, 2018). The edges of this end component can be chamfered, filed, or otherwise processed to reduce the possibility of sharp edges contacting the patient's mouth and causing pain or other discomfort. The lens disposed in this end component can be conformally selected as elliptical or beveled polygonal depending on the variation of the end component and its shape.

[0009] Industry experts hope to further improve the shape of the scanning head of digital impression machines in order to reduce the stimulation of the patient's oral cavity during oral scanning and thus improve the patient's comfort when the scanning head enters the mouth. Summary of the Invention

[0010] The purpose of this disclosure is to provide a scanning head for a digital impression instrument for the oral cavity, which has an improved shape and size, enabling patients to have a more comfortable experience when scanning their oral cavity with this scanning head.

[0011] To solve the above-mentioned technical problems, the scanning head according to this disclosure has the following features:

[0012] The housing is hollow and has an internal space. It has a closed first end and an open second end opposite to the first end. The scanning head has a first side extending between the first and second ends and a second side opposite to the first side. A window is provided on the first side.

[0013] The lens is fastened to the inner wall of the hollow housing, such that light entering the interior space of the housing from the second end can be reflected at the effective surface of the lens and exit through a window on the first side, leaving the interior space of the housing. The lens is beveled, forming a first volume and a second volume adjacent to the first volume.

[0014] The first volume structure is shaped like a truncated cone, with the back of the lens as the top surface and a sloping surface extending from the back as the outer peripheral surface. The truncated cone also has a bottom surface opposite the top surface.

[0015] In this case, the beveled surface of the lens forms a beveled angle with respect to the thickness direction of the lens, and

[0016] The second volume structure is a cuboid shape, with the front of the lens as the bottom surface and the bottom surface of the aforementioned truncated cone portion as the top surface, and the cuboid has a thickness between the aforementioned bottom surface and top surface.

[0017] According to this disclosure, the scanning head bevels and grinds the non-effective surface of the lens installed therein from the back of the lens at an angled angle. Compared with the original lens which is roughly cuboid in shape, the edge thickness of the ground lens is reduced. This reduces the size of the part of the scanning head housing that mates with the lens, i.e. the part used to fasten the lens, thereby reducing the entrance height of the scanning head's entry point into the patient's oral cavity and reducing patient discomfort during oral scanning.

[0018] It should be noted that the beveling and grinding of the lens includes a portion of the back and side surfaces of the rectangular prototype; the beveling and grinding does not directly reach the front surface of the lens. In other words, the lens is not beveled and ground over its entire thickness, but only over a portion of its thickness, thus avoiding any impact on the lens's reflectivity and consequently, avoiding any influence on the optical path in the digital impression scanner used by the scanning head.

[0019] Preferably, when the above-mentioned bevel angle is in the range of 55° to 65°, it can reduce the thickness of the lens edge without affecting the optical path, and also helps the corresponding part of the scanning head housing to be shaped and sized in a suitable way, such as tilting, thereby reducing the entry height of the scanning head.

[0020] Particularly preferred is that the bevel angle is 60°, which can minimize the edge thickness of the lens while meeting the requirements of the processing technology.

[0021] Preferably, the bevel angles of each bevel facet of the lens relative to the thickness direction of the lens are the same. This simplifies the processing of the lens, simplifies the structural design of the part of the scanning head housing that mates with the lens, and facilitates the manufacturing of the housing, for example, by molding and integral processing.

[0022] Alternatively, the lens is secured to the inner wall of the scanning head housing, for example, by means of an adhesive, such as glue, on its back side. This securing method facilitates the installation of lenses that have undergone bevel grinding.

[0023] Optionally, the lens is substantially secured to the inner wall of the top side of the scanning head housing by means of an adhesive, that is, to the inner surface of the top side of the hollow cylindrical housing, where the top side of the housing extends obliquely to the second side opposite to the first side where the window is provided. Specifically, the top side of the housing extends at an acute angle relative to the first side of the housing.

[0024] As explained above, the beveled lens reduces its edge thickness, allowing for a tilted extension of the top side of the housing relative to the first side. In particular, the smaller edge thickness of the lens allows for a smaller tilt angle between the top side and the first side of the housing. This results in a smaller maximum height of the scanner head's entry point at the same entry depth, reducing the likelihood that the tip of the scanner head, i.e., the end furthest from the first side, will scrape against the patient's oral cavity during intraoral scanning.

[0025] Here, the inlet height of the inlet portion of the scanning head is defined as the vertical distance between the first and second sides of the scanning head housing.

[0026] With an inlet depth of 40.00 mm, the inlet height of the scanning head according to this disclosure ranges from 15.8 to 20.55 mm.

[0027] Optionally, a groove is provided on the inner wall of the scanning head housing, and the groove is sandwiched between the first boss portion and the second boss portion. The groove is used to accommodate adhesive for fastening the lens, so that the lens is fastened to the scanning head housing with its back side by means of adhesive, and the back side of the lens rests on the first boss portion and the second boss portion.

[0028] The groove in the scanning head housing allows for control over the application area of ​​the adhesive used to fasten the lens, preventing the adhesive layer from becoming too thick. The protrusions on both sides of the groove facilitate lens positioning during bonding and fastening of the lens's back side, and also control the application area of ​​adhesive to the lens's back side. The first and second protrusions are, for example, elongated ribs that protrude relative to the aforementioned groove towards the interior space of the housing, or that protrude relative to the inner surface of the housing towards the interior space.

[0029] Furthermore, the lens after beveling and grinding can optionally be chamfered; specifically, the second volume of the lens can be chamfered. Here, the second volume of the lens after beveling and grinding is approximately rectangular in shape, but its thickness is relatively thin, so it can also be described as approximately rectangular. By chamfering the eight corners of this approximately rectangular second volume, the corners of the second volume of the lens are made smooth, facilitating the operation when fastening the lens and avoiding the risks that may arise during the lens fastening process due to sharp lens corners.

[0030] Furthermore, by combining the rounded corners of the lens with the beveling of non-effective surfaces, the occurrence of right angles in the lens's structure is reduced. This allows the corresponding parts of the scanning head housing used to fasten the lens, especially the corresponding parts at the top end of the scanning head, to be more rounded, without needing to conform to the right-angled corners of the lens. This reduces the manufacturing difficulty of the scanning head housing and improves production efficiency.

[0031] Specifically, when the lens of the scanning head according to this disclosure has the aforementioned beveled and chamfered structure, the first corners on both sides of the top of the scanning head housing are rounded. The first corners are specifically formed by the top side, the first side, and the corners formed by these and the two sides of the scanning head housing. The aforementioned two sides are located between the first side and the second side in the circumferential direction of the scanning head, namely the third side and the fourth side.

[0032] When viewed from the first side of the scanning head, the first corner formed between the first side and the top side is rounded with a radius between 4.25 mm and less than 6 mm.

[0033] Preferably, the radius of the rounded corner of the first corner is 5mm.

[0034] Optionally, the housing of the scanning head is constructed such that the lens, fastened to the inner wall of the top side of the scanning head housing, abuts against the inner surface of the scanning head housing with its side portion, particularly the side of the second volume which is constructed in a generally cuboid shape, especially against the inner surfaces of the aforementioned third and fourth sides of the scanning head housing. Thus, the lens is fastened to the inner surface of the scanning head housing by means of, for example, an adhesive, and conforms to the shape of the scanning head housing.

[0035] This disclosure also proposes a digital dental impression device having a scanning head designed and constructed according to any of the above-described schemes, and a handheld component, wherein the scanning head is mounted at the end of the handheld component with its open second end.

[0036] The oral digital impression device disclosed herein has a rounded inlet shape and a low inlet height, which reduces stimulation to the patient's oral cavity and improves the patient's comfort when using it for intraoral imaging.

[0037] Additional features and advantages described herein will be set forth in the detailed description below, and will be recognized by those skilled in the art as will be apparent from the following description or as will be apparent from practice of the embodiments described herein, including the detailed description below, the claims, and the accompanying drawings. Attached Figure Description

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

[0039] Figure 1 shows a lens in a scanning head according to an embodiment of the present invention;

[0040] Figure 2 shows a top view of a scanning head according to an embodiment of the present invention;

[0041] Figure 3 shows a side view and a cross-sectional view of the scanning head shown in Figure 2;

[0042] Figure 4 shows a longitudinal cross-sectional view of the first end portion of the scanning head shown in Figure 2;

[0043] Figure 5 shows a rear view of the first end portion of the scanning head shown in Figure 2; and

[0044] Figure 6 shows a front view of the first end portion of the scanning head shown in Figure 2. Detailed Implementation

[0045] Reference will now be made in detail to various embodiments of the invention, examples of which are shown in the accompanying drawings and described below. Although the invention will be described in conjunction with exemplary embodiments, it should be understood that this specification is not intended to limit the invention to those exemplary embodiments. Rather, the invention is intended to cover not only these exemplary embodiments, but also various alternatives, modifications, equivalents, and other implementations that may be included within the spirit and scope of the invention as defined by the appended claims. For ease of interpretation and precise definition in the appended claims, unless otherwise stated, the terms “upper,” “lower,” “inner,” and “outer” are used to describe features with reference to their location in the exemplary embodiments shown in the figures.

[0046] Figure 1 shows a lens M10 for a scanning head according to an embodiment of the present invention. Part (a) of Figure 1 shows a front view of the lens M10 as seen from the front side S22. Part (b) of Figure 1 shows a rear view of the lens M10 as seen from the back side S21. Part (c) of Figure 1 shows a side view of the lens M10.

[0047] Lens M10 is machined from a prototype with a generally rectangular parallelepiped structure. The corners of this parallelepiped are chamfered. Furthermore, as can be seen in parts (b) and (c) of Figure 1, the chamfered parallelepiped is subjected to beveling and grinding of non-effective surfaces starting from the back surface S21 of the lens M10. Thus, when viewed from the back surface S21, lens M10 is formed into a generally frustum-shaped portion, and eight beveled surfaces S11, S12, S13, S14, S15, S16, S17, and S18 are formed starting from the back surface S21 of the lens. Among them, beveled surfaces S11, S13, S15, and S17 are located at the aforementioned chamfered corners of lens M10, while beveled surfaces S12, S14, S16, and S18 are located on the edge side of lens M10. Here, the non-effective surfaces of lens M10 include the back surface S21 of lens M10 and the side surface of the aforementioned cuboid prototype before it is beveled.

[0048] The bevel angle of the bevel grinding process performed on the lens M10 starting from the back surface S21 is defined as the bevel angle relative to the thickness direction H of the lens M10 when viewed in a side view of the lens M10. As shown in part (c) of FIG1, the bevel angle α of the bevel surface S15 of the lens M10 relative to the thickness direction H of the lens M10 is 60°. Further, in this embodiment, the angles of other bevel surfaces S11 to S14 and S16 to S18, such as bevel surface S13, relative to the thickness direction H of the lens M10 are also 60°. In other words, in this embodiment, the bevel angles of the bevel grinding processes performed on each side surface of the lens M10 are the same.

[0049] Furthermore, as can be observed in part (c) of Figure 1, the beveled surfaces S11 to S18 originating from the back surface S21 of lens M10 do not extend directly to the front surface S22 of lens M10, but terminate at a certain distance from the front surface S22. In other words, the beveled grinding process of lens M10 starting from the back surface S21 does not directly reach the front surface S22 of lens M10, but terminates at a certain distance from the front surface S22. Therefore, lens M10 is composed of a first volume V1 and a second volume V2. The first volume V1 is a roughly frustoconical volume with the back surface S21 of lens M1 as its top surface and surrounded by beveled surfaces S11 to S18. The second volume V2 is a volume whose top surface is connected to the bottom surface of the first volume V1, and whose top surface is the bottom surface. As can be seen in part (c) of Figure 1, the second volume V2 is formed as a generally cuboid volume with chamfered corners, and the second volume V2 has a generally uniform thickness T20, which is the edge thickness of the lens M10 after beveling and grinding. This edge thickness is much smaller than the vertical distance from the front surface S22 to the back surface S21 of the lens M10, thereby reducing the edge thickness of the generally cuboid lens M10 and helping to reduce the entrance height of the scanning head of the digital impression machine to which the lens M10 is applied. Furthermore, the chamfering of the corners of the generally rectangular shape of the lens M10, specifically the corners of the generally cuboid second volume V2, also helps to reduce the molding difficulty of the corresponding parts of the housing of the scanning head on which the lens M10 is mounted. This will be explained in more detail below with reference to the accompanying drawings.

[0050] Referring next to Figures 2 and 3, a scanning head S50 for a digital impression instrument for the oral cavity is shown, in which a reflective lens M10 is mounted.

[0051] As can be seen in Figures 2 and 3, the scanning head S50 has a housing S60. The housing S60 is integrally formed by a process such as injection molding and is constructed as a hollow cylinder. The housing S60 thus has an inner surface and an outer surface, and has a certain thickness. The housing S60 is constructed to have a closed first end E1 and an open second end E2. The diameter of the generally cylindrical housing S60 gradually decreases from the second end E2 to the first end E1.

[0052] The housing S60 has a first side S31, a second side S32 opposite to the first side S31, and a top side S33. As can be seen in Figures 2 and 3, the first end E1 terminates with an inclined platform formed on the top side S33.

[0053] A window F10 is provided on the first side S31 of the housing S60. A lens M10 is installed on the inner wall S61 of the housing S60, near the first end E1, opposite to the window F10, so that the light from the light-emitting element of the digital impression instrument is refracted by the lens M10 and emitted through the window F10.

[0054] Since a portion of the scanning head S50, starting from the first end E1, extends into the patient's mouth when using a digital impression device, the size and shape of this part of the housing S60 of the scanning head S50 directly affect the patient's experience during oral scanning.

[0055] Specifically, the scanning head S50 is configured such that when the scanning head S50 is mounted at the end of the corresponding handheld component of the digital dental impression device via the second end E2, the metal carrier structure of the handheld component can extend into the hollow internal space of the housing S60 through the opening of the second end E2. Thus, light from the light-emitting element in the handheld component can propagate through the metal carrier structure through the internal space of the housing S60 and reach the lens M10 located near the first end E1 of the scanning head S50. Further, the light is reflected at the lens M10, then passes through the window F10 on the first side S31 of the housing S60 to reach the patient's oral cavity, and returns to the handheld component of the digital dental impression device via the aforementioned route, thereby achieving scanning and imaging of the patient's oral cavity.

[0056] Therefore, the lens M10 is a crucial component of the scanning head S50 in enabling image transmission into the patient's mouth, and the projection and illumination windows of the scanning head S50 play a decisive role in the lens M10. Furthermore, due to the fastening method of the lens M10, which will be explained below, the shape and thickness of the lens M10 directly affect the size and height of the support structure of the scanning head housing S60.

[0057] The following section explains the installation of lens M10 in the scanning head S50.

[0058] Figure 3(b) shows the cross-section BB seen when the line BB along Figure 3(a) cuts through the scanning head S50 near the first end E1 of the scanning head S50.

[0059] As can be seen in part (b) of Figure 3, the lens M10 is fastened to the inner wall S61 of the housing S60 of the scanning head S50 as described above, and is opposite to 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 by means of adhesive on its back surface S21. 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.

[0060] 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.

[0061] 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.

[0062] Figure 4 shows a portion of the longitudinal central section of the scanning head S50, specifically a part near the first end E1.

[0063] As shown in Figure 4, 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. Adhesive for fastening the lens M10 is applied to this groove R3. Further, as shown in Figure 4, the length of the groove R3 is less than the length of the back surface S21 of the lens M10, such that, apart from a portion contacting the adhesive applied to the groove R3, the remaining portion of the back surface S21 of the lens M10 rests against the first boss P1 and the second boss P2 located on both sides of the groove R3, and no adhesive is applied to the surfaces of the first boss P1 and the second boss P2. The first boss P1 and the second boss P2 thereby assist in positioning the lens M10 for installation, facilitating the installation of the lens M10 on the inner surface of the top side S33 of the inclined first end E1, and their combination with the groove R3 limits the application range of the adhesive used to fasten the lens M10.

[0064] As can also be seen in Figure 4, the two sides of the second protrusion P2 are defined by the groove R3 and the recessed portion R2 described above, respectively. On the other side of the recessed portion R2 is the abutment portion S42 described above. One side of the second volume V2 of the lens M10, which is fastened inside the scanning head S50, abuts against the abutment portion S42 for a form fit. The recessed portion R2 is located approximately on the inner surface of the corresponding first corner C1 formed by the junction of the top side S33 and the first side S31 of the scanning head housing S60. The aforementioned junction of the scanning head housing S60 between the first side S31 and the top side S33 is constructed as two rounded first corners C1. Similarly, the junction of the housing S60 between the second side S32 and the top side S33 is constructed as a rounded second corner C2. The first corner C1 is further away from the second end E2 than the second corner C2, and therefore, when using the scanning head S50, it first enters the patient's mouth.

[0065] As shown in the figure, the window portion F10 is recessed towards the internal space of the scanning head S50 relative to the first side S31 of the scanning head S50, and the window portion F10 also has an inclined transition portion T10 on the side away from the first end E1 to transition to the first side S31, while most of the side of the window portion F10 extends horizontally in the drawing of Figure 4.

[0066] It can be noted that the top side S33 of the first end E1 of the scanning head S50 is not perpendicular to the first side S31, but rather inclined. Therefore, the lens M10, which is fastened to the inner surface of the top side S33 of the scanning head S50, and the window F10 opened on the first side S31 are inclined at an angle to each other. In this embodiment, according to the imaging requirements of the corresponding digital impression instrument, the corresponding dimensions of the lens M10 and the window F10, as well as their relative positional relationship, meet the size requirements of a 16mm × 14mm projection and illumination window.

[0067] As can be seen in Figures 3 and 4, because the lens M10 is beveled from the back side S21, the first volume V1 is reduced compared to the initial cuboid structure, and as explained above, the edge thickness T20 of the lens M10 is reduced. This allows the top side S33 of the housing S60 used to secure the lens M10 to be tilted at a smaller angle, thereby reducing the distance between the first side S31 and the second side S32 at the first end E1 of the scanning head S50. This results in a reduction in the entrance height Hi of the scanning head S50. The entrance height Hi will be further explained below with reference to Figure 5.

[0068] Turning to Figure 5, the depth to which the scanning head S50 extends into the patient's oral cavity during use is calculated from the foremost point of the first end E1 of the scanning head S50, i.e., the foremost point of the first corner C1. The inlet height Hi of the scanning head S50 is the distance between the first side S31 and the second side S32. With an inlet depth Li of 40.00 mm, the minimum inlet height Hi of the scanning head S50 is 15.80 mm, and the maximum inlet height Hi is 20.55 mm. The minimum inlet height Himin of the scanning head S50 is the vertical distance from the lowest point of the second side S32 to the first side S31 when the scanning head S50 is viewed from the side. In the illustrated embodiment, the other endpoint of the vertical line connecting the lowest point of the second side S32 to the first side S31 is located at the window F10. The inlet height Hi of the scanning head S50 then gradually increases as it moves away from the first end E1 of the scanning head S50, and the maximum inlet height Himamax occurs at a distance of 40.00 mm from the vertex of the first corner C1. The minimum entry height Himin of the scanning head S50 is further reduced by the oblique cutting of the lens M10, which reduces the difficulty of the scanning head S50 entering the patient's oral cavity and also reduces the possibility that the second corner C2 and the second side S32 may scrape the patient's gums or other parts of the oral cavity when using the scanning head S50 for scanning.

[0069] Furthermore, by chamfering the corners of the lens M10, especially the corners of the second volume V2 which is approximately cuboid in shape, the roundness of the corresponding portion of the first end E1 of the housing S60 of the molded scanning head S50 and the aforementioned corner of the lens M10 is also improved. This will be further explained below with reference to FIG6.

[0070] Figure 6 shows a partial front view of the first end E1 of the scanning head S50 as seen from the first side S31 of the scanning head S50.

[0071] As shown in Figure 6, the two first corners C1 on the top side of the first end E1 of the scanning head S50, near the observer, i.e., on the first side S31, are rounded. These two first corners C1 are rounded with a radius R relative to the window F10 provided on the first side S31.

[0072] In the illustrated embodiment, the radius used for the rounded corner treatment of the first corner C1 is R = 5 mm. Figure 6 also schematically shows the positions of the minimum radius Rmin and the maximum radius Rmax of the rounded corner of the first corner C1. During injection molding, the maximum radius Rmax used for the rounded corner treatment of the two first corners C1 of the housing S60 of the scanning head S50 is 6 mm, while the minimum radius Rmin is 4.25 mm. These two first corners C1 of the scanning head S50 are the parts of the scanning head S50 that easily come into contact with the patient's oral mucosa and gums when scanning inside the patient's oral cavity.

[0073] The aforementioned inlet height Hi of the scanning head S50, particularly the minimum inlet height Himin, is reduced, and the radius of the rounded corner treatment at the first corner C1 at the first end E1 of the housing S60 achieves a more rounded corner of the scanning head housing. This helps reduce the impact of the scanning head S50's movement within the patient's mouth on the patient's sensitive oral nerves. Furthermore, the radius of the rounded corner makes the first corner C1 more rounded and also reduces the molding difficulty of the integrally molded housing S60 of the scanning head S50, achieving a smooth transition of the curved surface. While meeting the injection molding process, it achieves the effect of no sharp edges or abrupt structures in the inlet portion of the scanning head S50. This also helps improve the manufacturing efficiency of the housing S60 of the scanning head S50.

[0074] [Other Embodiments]

[0075] In other embodiments not shown, depending on the requirements for the entry height of the scanning head S50 and the fitting requirements of the housing S60 of the scanning head S50, the bevel angle α formed by the bevel of the lens M10 relative to the thickness direction H of the lens M10 can be other values ​​in the range of 0 to 90°, but excluding the endpoints. For example, the bevel angle can be 55 to 65°.

[0076] According to the present disclosure, the digital dental impression device reduces the peripheral fit dimensions between the lens and the molded scanning head housing by mechanically cutting and rounding the corners of the reflective lens disposed in the scanning head, and improves the patient's tactile experience when the molded structural component, which serves as the carrier of the lens, comes into direct contact with the patient's oral cavity. Furthermore, by obliquely grinding the ineffective area of ​​the lens in the thickness direction, the height dimension of the fit between the lens and the molded scanning head housing structural component is reduced, thereby reducing the entry height of the scanning head into the patient's mouth, thus optimizing the structure of the molded structural component.

[0077] The combination of oblique grinding and rounding of the lens disclosed herein can be applied not only to the field of digital dental impression instruments, especially the scanning head of the handheld component of a wireless digital dental impression instrument, but also to any imaging and projection device with a lens, such as endoscopes, projectors, cameras, VR glasses and other products.

[0078] Within the scope of this invention, various embodiments can be freely combined, or appropriately modified or omitted.

[0079] List of reference numerals: C1 First corner; C2 Second corner; E1 First end; E2 Second end; F10 Window; H Thickness direction; Hi Inlet height; Himin Minimum inlet height; Hima Maximum inlet height; Li Inlet depth; M10 Lens; P1 First boss; P2 Second boss; P3 Third boss; R (rounded corner) radius; Rmin Minimum radius; Rmax Maximum radius; R1 Recess; R2 Recess; R3 Groove; S11-S18 (lens) cut surface; S21 (lens) back side; S22 (lens) front side; S31 (housing) first side; S32 (housing) second side; S33 (housing) top side; S34 (housing) third side; S35 (housing) fourth side; S41 abutment; S42 abutment; S50 Scanning head; S60 (scanning head) housing; S61 (housing) inner wall; T10 Transition section; T20 Thickness α Bevel angle; V1 First volume; V2 Second volume.

Claims

1. A scanning head (S50) for use in a digital impression instrument for dentistry, characterized in that, The scanning head (S50) has a hollow housing (S60) with a closed first end (E1) and an open second end (E2) opposite to the first end (E1). The housing (S60) also 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). A window (F10) is provided on the first side (S31). The scanning head (S50) also has a lens (M10), which is fastened to the inner wall (S61) of the housing (S60), such that light entering the interior space of the housing (S60) from the second end (E2) can be reflected at the effective surface of the lens (M10) and exit from the window (F10) into the interior space of the housing (S60). The lens (M10) is composed of a first volume (V1) and a second volume (V2) connected to the first volume (V1). The first volume (V1) is formed in the shape of a truncated cone, wherein the truncated cone has the back surface (S21) of the lens (M10) as its top surface, and the oblique cut surface (S11-18) extending from the back surface (S21) as its outer peripheral surface, and the truncated cone has a bottom surface opposite to the top surface. Wherein, the oblique surface (S11-S18) of the lens (M10) forms an oblique angle (α) with respect to the thickness direction of the lens (M10), and the oblique angle (α) ranges from 0 to 90°, and The second volume (V2) is formed in the shape of a cuboid, with the front face (S22) of the lens (M10) as the bottom surface and the bottom surface of the truncated cone portion as the top surface, and has a thickness (T20) between the top surface and the bottom surface of the cuboid.

2. The scanning head (S50) as described in claim 1, characterized in that, The angle (α) of the oblique cut is 55-65°.

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

4. The scanning head (S50) as described in claim 3, characterized in that, A groove (R3) is provided on the inner wall (S61) of the housing (S60), and the groove (R3) is sandwiched between the first boss (P1) and the second boss (P2). The groove (R3) is used to accommodate the adhesive to fasten the lens (M10) in the housing (S60) of the scanning head (S50) with the back side (S21), and to allow the back side (S21) to rest on the first boss (P1) and the second boss (P2).

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

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

7. The scanning head (S50) as described in claim 1 or 2, characterized in that, The front side (S22) of the lens (M10) is designed to be rectangular with rounded corners.

8. The scanning head (S50) as described in claim 7, characterized in that, The first corner (C1) between the first side (S31) and the 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 described in claim 1 or 2, characterized in that, The lens (M10) abuts against the abutment portions on the inner surfaces of the first side (S31) and the second side (S32) respectively.

10. A digital dental impression instrument, characterized in that... It has a handheld component and a scanning head (S50) as described in any one of claims 1 to 9, wherein the scanning head (S50) is mounted at the end of the handheld component with its open second end (E2).

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