KR102033426B1 - Intra-Oral Scanner - Google Patents

Abstract

An oral scanner having a so-called quick 3D mode is disclosed, which acquires monochrome 3D model data for an oral structure in half the time required compared to the scanning time of a conventional oral scanner. The oral cavity scanner which concerns on this invention is a pattern light source which irradiates pattern light; An auxiliary light source for irradiating visible light; An optical camera for photographing a depth information frame using the pattern light and a color information frame using the visible light; Switching between a first mode of controlling the pattern light source, the auxiliary light source, and the optical camera to alternately photograph the depth information frame and the color information frame one or more times; and a second mode of continuously photographing the depth information frame. A control unit; And an image processor for generating color 3D model data by matching the depth information frame and the color information frame in the first mode, and generating monochromatic 3D model data by matching the depth information frame in the second mode. It is configured by.

Description

Oral Scanner {Intra-Oral Scanner}

 The present invention relates to a 3D scanner. More specifically, in order to generate 3D model data of the intraoral structure, the probe tip portion is inserted into the mouth of the subject to acquire a plurality of optical images, and the plurality of optical images are matched to generate 3D model data. To an oral scanner.

The oral cavity scanner is a kind of 3D scanner that acquires a plurality of optical images of a target object through a series of scanning sequences, and generates 3D model data of the target object using them. An oral scanner refers to a device configured to be suitable for obtaining a series of optical images of the body part, especially the structure inside the oral cavity, such as teeth and gums, among these 3D scanners.

An example of a method of taking an optical image through an oral scanner to acquire 3D model data is an active stereo vision method, in which a previously known patterned light is irradiated onto a tooth surface, and an irradiated pattern By taking a plurality of optical images with two or more optical cameras, information on the three-dimensional shape of the surface, that is, depth information according to the deformation of the pattern is obtained.

Meanwhile, in order to design a dental prosthesis, such as a denture and an implant, in a dentistry similar to a real tooth, information on color and texture of the tooth surface, that is, color and texture, may be required in addition to the three-dimensional shape of the tooth. In order to provide information on the color and texture of the oral structure, such as a tooth, the dental oral scanner additionally captures a color image using a visible light source at each position where the pattern light projection image is photographed. Get color and texture data. As described above, color image frames for obtaining color and texture information are added as much as the number of frames for obtaining depth information, thereby increasing the number of photographing frames to increase the time required for scanning, thereby increasing the inconvenience of the patient. Furthermore, even when color and texture information such as teeth is not required, there is a problem in that such inconvenience must be taken.

United States Patent Application Publication US 2012-0218389 (2012.08.30) United States Patent Application Publication US 2014-0119622 (2014.05.01)

The present invention has been proposed in order to solve the above-described problems, an oral scanner having a so-called quick 3D mode, which acquires the solid color 3D model data for the oral structure in about half as short as the scanning time of the conventional oral scanner. The purpose is to provide.

In addition, an object of the present invention is to provide an oral scanner having a color 3D mode for acquiring comparable levels of color 3D model data even with a smaller number of visible light image frames compared to the conventional oral scanner with the quick 3D mode. There is this.

In order to solve the above problems, the oral cavity scanner according to the present invention, the pattern light source for irradiating pattern light; An auxiliary light source for irradiating visible light; An optical camera for photographing a depth information frame using the pattern light and a color information frame using the visible light; A first mode for alternately photographing the depth information frame and the color information frame one or more times by controlling the pattern light source, the auxiliary light source, and the optical camera; and a second mode for continuously photographing the depth information frame A control unit; And an image processor configured to generate color 3D model data by matching the depth information frame and the color information frame in the first mode, and generate monochrome 3D model data by matching the depth information frame in the second mode. It is configured by.

The second mode may photograph only the depth information frame.

Meanwhile, the oral cavity scanner displays first and second display windows on a display, wherein the first or second display window displays a color or monochrome 3D model during registration with the color or monochrome 3D model data, and the second display window displays the color or monochrome 3D model. The apparatus may further include a viewer that displays the current photographed image as the depth information frame.

The controller may be configured to repeat photographing the color information frame once in a unit cycle after photographing the depth information frame two or more times in the first mode.

In this case, the controller may be configured to continuously photograph the depth information frame after the photographing of the color information frame in the first mode until the margin of the overlapping region with the color information frame becomes a predetermined value or less. .

According to the present invention, it is possible to provide an oral scanner having a so-called quick 3D mode, which acquires monochrome 3D model data of the oral structure in a short time that is half the level of the scanning time required by the conventional oral scanner.

In addition, according to the present invention, it is possible to provide an oral scanner having a color 3D mode for acquiring comparable levels of color 3D model data with a smaller number of visible light image frames than the conventional oral scanner with the quick 3D mode. .

Through this, the oral cavity scanner according to the present invention has the effect of reducing discomfort of the patient by allowing the oral scanning sequence to be finished up to twice as fast according to the need of color texture information. In addition, even when color texture information is required, the number of color image acquisition frames is reduced, thereby reducing the time and effort required to acquire color 3D model data.

Figure 1 shows the oral cavity according to an embodiment of the present invention is separated into the main body and the probe tip.
2 is a view illustrating photographing timings of a depth information frame and a color information frame according to a scanning mode selection in an oral cavity scanner according to an exemplary embodiment of the present invention.
3 shows a viewer screen of the oral cavity scanner in accordance with an embodiment of the present invention.
4 is a diagram illustrating photographing timings of a depth information frame and a color information frame according to a scanning mode selection in an oral cavity scanner according to an exemplary embodiment of the present invention.
Figure 5 shows an example of the frame trajectory during the scanning sequence progress using the oral cavity scanner according to an embodiment of the present invention.
Figure 6 shows an example of the color 3D mode frame configuration method of the oral cavity scanner according to an embodiment of the present invention.

Hereinafter, various embodiments of the present invention will be described with reference to the drawings. Through the embodiments will be understood the technical spirit of the present invention more clearly. The present invention is not limited to the embodiments described below. Like reference numerals denote elements of the same nature, and descriptions of components having the same reference numerals as components described in one drawing may be omitted in the description of the other drawings.

Figure 1 shows the oral cavity according to an embodiment of the present invention is separated into the main body and the probe tip.

The oral cavity scanner 100 is largely composed of a main body 110 and a probe tip 120. The pattern light source 113, the auxiliary light source 115, and the optical camera 114 are mounted to the front of the main body 110, and the rear end of the probe tip 120 is located in front of the main body 110. And the front end is inserted into the mouth of the subject. The front end of the probe tip 120 is formed with a scan hole 121 opened toward the subject's teeth and the like, and the reflector is inclined inside the scan hole 121. The reflector reflects the light emitted from the above-described two light sources 113 and 115 and sends it out through the scan hole 121, and the light reflected back to the oral structure such as a tooth is returned to the optical camera 114. Reflecting toward the main body 110.

For example, the pattern light source 113 emits pattern light including a pattern having a clear contrast in a known shape, and includes a light source disposed inside the main body 110 and a pattern mask provided in front of the light source. Can be configured. The pattern engraved in the pattern mask may be, for example, a random dot pattern, but is not limited thereto. The auxiliary light source 115 emits visible light, and a white light source suitable for capturing color images using the optical camera 114 is sufficient.

The oral cavity scanner 100 according to the present exemplary embodiment is an active stereo vision system, and includes two optical cameras 114 disposed at both sides with the pattern light source 113 in the center. The optical camera 114 captures a field of view (FOV) irradiated with the pattern light emitted from the pattern light source 113 or the visible light emitted from the auxiliary light source 115 through the scan hole 121 ( Shoot the image in F) frame by frame. When the scanning sequence starts, the user evenly scans various parts of the oral structure to obtain 3D model data while the oral scanner 100 captures images of a plurality of frames at a predetermined frame rate. In this case, the main body 110 of the oral cavity scanner 100 operates the pattern light source 113 at a depth information frame photographing timing, and operates the auxiliary light source 115 at a color information frame photographing timing.

In other words, whether the photographed image frame is a depth information frame or a color information frame is substantially determined according to the auxiliary light source 115 or the pattern light source 113 operated at the shooting timing. Each mark may be added to the unit data of the depth information frame and the color information frame for information processing after photographing.

Meanwhile, a technique of projecting a previously known pattern onto a part of an object and acquiring depth information of the surface by using images taken at different angles of the pattern deformed by the three-dimensional shape of the part, or an optical camera The technique of acquiring the 3D model including the surface color and the texture by merging the color images of the portion photographed by using may use techniques known in the oral scanner art.

The oral cavity scanner according to the present invention comprises two scanning modes for acquiring a 3D model of an object, including a first mode (hereinafter referred to as a color 3D mode for convenience) and a second mode (hereinafter referred to as a quick 3D mode for convenience). Can be. The quick 3D mode can be configured to obtain monochrome 3D model data for the oral structure within the shortest time. The monochromatic 3D model data may include information about the three-dimensional shape without information on the surface color or texture of the oral structure, and may be expressed in one color or black and white on the screen of the viewer. The color 3D mode may be configured to acquire color 3D model data containing surface color in the same manner as a conventional oral scanner, and to obtain color 3D model data by a scanning sequence in which the number of color information frames is reduced than before. It may be configured.

2 is a view illustrating photographing timings of a depth information frame and a color information frame according to a scanning mode selection in an oral cavity scanner according to an exemplary embodiment of the present invention.

(a) shows the ON / OFF timing of the depth information frame and color information frame when scanning is performed in the color 3D mode. f1 to f1000 represent a sequence of a plurality of unit frames photographed by the above-described optical camera, and it is assumed that a scan sequence includes 1000 image frames. The number of image frames constituting the scan sequence may vary depending on the size of the region to which the 3D model is to be obtained. The frame rate, which is the number of frames taken per hour by the optical camera, can remain the same when in color 3D mode or in quick 3D mode.

When scanning is performed in the color 3D mode, as shown in (a), the depth information frame and the color information frame may be alternately photographed by the optical camera. For example, at the first frame f1 timing, the above-described pattern light source is operated to photograph the depth information frame, and at the second frame f2 timing, the above-described auxiliary light source is operated to photograph the color information frame ( ON), and the scanning sequence can be progressed by repeating this operation pattern. In this case, when the total number of frames is 1000, 500 depth information frames and 500 color information frames are captured. The oral cavity scanner matches 500 depth information frames with each other to generate 3D model data, which can be displayed through the viewer. Meanwhile, the 500 color information frames are used to construct the surface color and texture of the 3D model data. As a result, the oral cavity scanner provides 3D model data including surface color and texture through a scanning sequence in color 3D mode.

For reference, the waveform and ON / OFF display shown in the timing chart of this figure are used to determine whether or not the depth information frame is photographed by the optical camera for each of a plurality of frame timings. It does not indicate the waveform or level of a specific signal.

(b) shows the ON / OFF timing of the depth information frame and color information frame when scanning is performed in the quick 3D mode. The number of frames shown is 500, which is the number of frames required to obtain monochrome 3D model data for an area of the same size as the area scanned in the color 3D mode in the above-described embodiment (a). As described above, the oral cavity scanner according to the present invention may provide 3D model data only by photographing half the frames in the quick 3D mode as compared to the color 3D mode.

In the timing chart shown, the depth information frame (Depth) is continuously shot (ON) every frame (f1 to f500) from the beginning to the end of the scanning sequence in the Quick 3D mode, and the color information frame (Color) remains OFF. . As a result, 3D model data can be completed in half the time compared to the color 3D mode described above on the assumption that the frame rate of the optical camera is constant. In this case, since the 3D model does not include information on the surface color and texture, the 3D model may be three-dimensionally expressed through a gray scale of black and white or a gray scale of a predetermined color.

This quick 3D mode is not required for the color texture information of the oral structure, for example, to check the placement of the teeth being corrected, or to obtain information for the production of metal prosthetics irrespective of the color of the oral cavity. Discomfort of the patient can be greatly reduced during scanning.

3 shows a viewer screen of the oral cavity scanner in accordance with an embodiment of the present invention.

The viewer of the oral cavity scanner may be installed in a desktop PC or a tablet PC in the form of software. The viewer may receive and process a plurality of frame information received from the oral cavity scanner, and display the final result, the intermediate result, and / or the received real-time image frame on the viewer window 331 of the display device 330. . As a more specific example, the viewer window 331 may display menu buttons 332 and 333 corresponding to selectable scanning modes, that is, the quick 3D mode and the color 3D mode, respectively. When the quick 3D mode is selected and scanning is performed, the first display window 334 displays the 3D image 3T of the matched monochromatic 3D model generated by matching depth information frames received from the oral cavity scanner to the present time. The second display window 335 may display the 2D optical image 2T of the depth information frame received at the time point closest to the present time from the oral cavity scanner.

4 is a diagram illustrating photographing timings of a depth information frame and a color information frame according to a scanning mode selection in an oral cavity scanner according to an exemplary embodiment of the present invention.

In the figure, (a) is a timing chart at the time of selecting a color 3D mode, and (b) is a timing chart at the time of selecting a quick 3D mode. Since (b) is the same as in the case of FIG. 2 (b) described above, description thereof is omitted and only (a) will be described herein.

When the color 3D mode of the oral cavity scanner according to the present embodiment is selected, the depth information frame (Depth) is photographed (ON) during a plurality of consecutive frames, for example, from the first frame f1 to the third frame f3. The color information frame Color may be photographed (ON) in the next fourth frame f4. The depth information frame Depth is photographed in the fifth frames f5 to seventh frame f7, and the color information frame Color is photographed in the next eighth frame f8. This cycle can be repeated periodically. The number of depth information frames continuously photographed may be set in advance, and may be set differently depending on the speed at which the probe tip moves during scanning.

As such, the reason why the frequency of capturing the color information frame can be lowered is that, in the case of the depth information frame, a portion overlapping between the capturing area of one frame and the capturing area of the next frame must be sufficiently secured for accurate image registration. This is because in the case of the information frame, even if only one color information frame is included in one photographing area, color and texture information of all parts of the photographing area can be secured.

Figure 5 shows an example of the frame trajectory during the scanning sequence progress using the oral cavity scanner according to an embodiment of the present invention.

In the drawing, reference numeral T denotes a patient's dentition, and reference numeral Fn denotes an imaging area photographed in one image frame, that is, one depth information frame or one color information frame. Reference numeral FP shows an example of a trajectory in which the image frame photographing area Fn moves during the scanning sequence. The FP was originally a trajectory across the upper and both sides of the patient's dentition (T), but here it was marked separately beside the dentition to avoid congestion.

Figure 6 shows an example of the color 3D mode frame configuration method of the oral cavity scanner according to an embodiment of the present invention.

According to the present embodiment, as shown in (a), the oral cavity scanner photographs the first color information frame C1 during the oral scanning sequence in the color 3D mode, and subsequently, the plurality of depth information frames D1 and D2. ), But comparing the photographing area of the last information frame (D2) and the photographing area of the first color information frame (C1) is the margin (m) of the overlapping area is a certain value ( Sm) or less, the second color information frame C2 may be photographed. The configuration including the operation and the control may be implemented by a control unit for controlling the operation of the oral cavity scanner.

Here, the predetermined value Sm may be set in consideration of the moving speed of the probe tip, and may be defined as a value such as an overlapped width or an overlapped area between the photographing area and the photographing area. As described above, since the color information only needs to be secured for one frame of any part of the object to be photographed, in this configuration, the image frame photographed by the oral cavity scanner is obtained by securing the color information by the first color information frame C1. This is to secure the second color information frame C2 before completely leaving the area.

(b) shows the above configuration in the form of a flow chart. One color information frame is photographed, and then a depth information frame is photographed, and the photographing area of the photographed depth information frame is compared with the photographing area of the last color information frame, and the overlapping margin m is set to a predetermined value. If greater than Sm, the process continuously repeats the process of photographing the depth information frame, and if the margin m is less than or equal to the predetermined value Sm, a new color information frame is photographed. Through this configuration, it is possible to reduce the time required for photographing the color information frame, and the scanning time for securing the color 3D model can be shortened.

The various embodiments described above are provided to help the understanding of the present invention through specific examples, and the present invention is not limited thereto.

100: Oral Scanner
110: main body 113: pattern light source
114: optical camera 115: auxiliary light source
120: probe tip 121: scan hole
330: display device 331: viewer window
334: first display window 335: second display window

Claims (5)

A pattern light source for irradiating pattern light;
An auxiliary light source for irradiating visible light;
An optical camera for photographing a depth information frame using the pattern light and a color information frame using the visible light;
A controller configured to control the pattern light source, the auxiliary light source, and the optical camera to alternately photograph the depth information frame and the color information frame one or more times;
An image processor for generating color 3D model data by matching the depth information frame and the color information frame,
The controller repeats photographing the color information frame once in a unit cycle after continuously photographing the depth information frame two or more times, and after capturing the color information frame, the margin of the overlapping region with the color information frame is equal to or less than a predetermined value. To continuously shoot the depth information frame until
Oral scanner. The method of claim 1,
The control unit. Switch between a first mode in which the depth information frame and the color information frame are alternately photographed one or more times, and a second mode in which the depth information frame is continuously photographed;
The image processor generates the color 3D model data in the first mode and generates the monochrome 3D model data by matching the depth information frame in the second mode.
Oral scanner. The method of claim 2,
In the second mode, only the depth information frame is photographed.
Oral scanner. The method of claim 2,
A first and a second display window are displayed on a display, wherein the first display window displays a color or monochrome 3D model being matched with the color or monochrome 3D model data, and the second display window displays the current photographed image as the depth information frame. Further comprising a viewer to display,
Oral scanner. delete

Images