AT506688B1 - APPENDIX FOR A DEVICE FOR THE OPTICAL DETECTION OF SURFACES - Google Patents

Description

Austrian Patent Office AT 506 688 B1 2009-11-15

Description: [0001] The invention relates to an attachment according to the preamble of claim 1.

Various lighting devices for surfaces, such as uneven surfaces of teeth, are known from the prior art. Such illumination devices are used, among other things, to support or enable the use of detection or measuring instruments, for example image-capturing, image-forming or image-yielding units, apart from the mere illumination of the tooth surfaces. By means of such detection devices, various surface parameters, including the color, but also the roughness, the reflectivity, the structure, etc., can be measured. Thus, for example, in the measurement of the color of teeth, the respective tooth is illuminated and, by means of an intraoral camera or the like, an electronic image of the tooth is carried out with subsequent color determination.

In order to obtain a clear, high-quality and meaningful image or a clear color impression, it is advantageous to exclude all possible reflections or disturbing influences. For this purpose, numerous articles are known, which can be plugged or placed on such detection units or intraoral cameras. Such essays usually have a ring-like support surface, optionally made of soft material, with a round or circular opening. The attachment is applied to the sample surface, whereby the properties of the sample surface enclosed by the opening are measured by the detection unit. The interfering medium air is located between the detection unit and the sample surface. Such devices are known for example from WO 00/12020 or US 6,244,863. Furthermore, EP 1 730 438 discloses an attachment for a lighting device which has a harder, more rigid transparent guide body and a transparent, softer, more flexible cushion body which bears in a form-fitting manner against the light exit surface of the guide body. With this essay, it is advantageously possible to illuminate surfaces. Due to the design of the guide body as a rigid solid component, greater pressure can be applied to the sample surface. The use of a soft cushion body ensures that the attachment adapts to any unevenness of the surface and can fill it as far as possible. This synergistic effect ensures that no or only minimal quality-reducing gaps remain between the sample surface and the attachment. Furthermore, it is ensured that it can come through the soft and optionally elastic cushion body to no injury to the sample surface, for example, the enamel or the gums. In addition, scattering effects are minimized in the light supply and the light can be passed from the light source almost lossless to the sample surface.

However, it has been shown in practice that it is necessary to optimally adapt the lighting to the surface to be measured in order to achieve the best possible results.

It is therefore an object of the present invention to provide an article or develop further, which has the above advantages and with the optimal illumination of the surface to be detected can be achieved.

This object is solved by the characterizing features of claim 1, by providing that the light exit surface of the guide body is concave or convex curved.

In this way, optimal lighting can be achieved for each individual case. By the corresponding common selection of the refractive indices of the materials of the guide body and the cushion body and the selection of a concave or convex curvature of the light exit surface of the guide body, the light emanating from a light source is correspondingly scattered or collected and the attachment acts either as a diverging lens or as a converging lens. whereby, as required, either a homogeneous illumination or uniform illumination of the entire sample surface can be achieved or whereby the brightness in a desired area can be increased in a targeted manner, which is advantageous, for example, when a central, locally limited structure is to be analyzed. The dependent claims relate to advantageous embodiments of the invention: The features of claim 2 ensure optimum illumination or image quality. Also can be better influenced on any edge distortions.

According to the features of claim 3, a small and compact attachment is obtained that is easy to manufacture and easy to integrate into existing systems or devices.

In this context, it is particularly advantageous if the article is constructed constructively according to the features of claim 4.

For the manufacture and handling, it is advantageous if the article meets the features of claim 5.

A stable and easy-to-produce article advantageously has the features of claim 6. Such an essay is also shatter-proof.

Furthermore, it is advantageous if the materials of the guide body are selected according to the features of claim 7. This ensures that the guide body is stable and durable and can withstand the pressure exerted and the cushion body can be gently and snugly applied to the sample.

The features of claim 8 describe the possible design variants of the article by the advantageous synergistic combination of the curvature of the light exit surface of the guide body with the selection of the ratio of the refractive indices to each other. By appropriate selection of these two parameters, the refraction of light can be influenced very easily and the illumination of the surface can be optimally controlled, depending on whether a more focused central illumination or homogeneous illumination is advantageous.

In claim 9, an advantageous arrangement is described.

For better handling or for mounting various devices, such as lighting and / or detection units, etc., it is advantageous to make an arrangement so that the features of claim 10 are formed. From a constructive point of view, this is a very simple solution.

For generating diffused light advantageously the feature of claim 11 may be provided.

In order to achieve optimum image quality or illumination quality, it is advantageous if the light source or the detection unit according to claims 12 and 13 are arranged.

Further advantages and embodiments of the invention will become apparent from the description and the accompanying drawings.

The invention is illustrated schematically with reference to advantageous embodiments in the drawings and will be described below with reference to the drawings, for example.

Fig. 1 shows an essay with a spherically plano-convex guide body.

Fig. 2 shows an essay with an aspheric plano-convex guide body.

Fig. 3 shows an essay with a spherical plano-concave guide body.

Fig. 4 shows an essay with an aspherical plano-concave guide body.

Fig. 5 shows the cross section of an attachment or an arrangement including lighting and detection device.

Fig. 6 shows the cross section of an arrangement or Intraoralkamera Fig. 1 shows schematically the structure of an article according to the invention 1. The article 1 comprises a guide body 2 and a cushion body 3. 2/10 Austrian Patent Office AT 506 688 B1 The guide body 2, which is in the form of a solid solid body, consists of a transparent, preferably homogeneous, colorless and / or optically clear material which, when used as intended, can be termed hard and rigid. Materials which are suitable for this purpose are, for example, glass or plastic, preferably polymethyl methacrylate, polycarbonate, polyamide, styrene-acrylonitrile (SAN), polystyrene, potting compounds or casting resins based on epoxy resin, polyurethane resin, organopolysiloxane or the like, in particular with a ball compression hardness of> 100 measured according to ISO 2039-1.

The guide body 2 has a substantially planar or planar, the light source 21 and the detection unit 15 facing the light entry surface 6 and the sample surface 10 facing light exit surface 4. As usual in optical representations, runs in Figs. 1 to 5 shows the path of the light emanating from a light source 21 from left to right and is also indicated by an arrow.

In addition to the guide body 2 or at the light exit surface 4 of the guide body 2 is a transparent, preferably homogeneous, colorless and / or optically clear, cushion body 3 with a light entrance surface 30 and a substantially planar, light exit surface 31, arranged with its light entry surface 30 is positively and materially applied to the light exit surface 4.

This cushion body 3 is formed as a solid body and also consists of a transparent, preferably homogeneous, colorless and / or optically clear, material. In contrast to the guide body 2, the cushion body 3, however, consists of such a material or is designed such that it can adapt, in particular reversibly, to the shape, structure or to the profile of the surface 10 to be detected, so that as little air as possible between the sample surface 10 and the cushion body 3 remains. For this purpose, in particular, a deformable, conformable, flexible and / or elastic material, preferably with a Shore A hardness of <40, in particular between 10 and 20, measured according to the A scale, or with a penetration of 150 g heavy needle by 0.1 mm, used, for example, silicone or silicone derivatives or polyurethanes. The cushion body 3 is advantageously gel-like soft, but does not melt, so it is dimensionally stable.

The material of the cushion body 3 thus has a lower hardness than the material of the guide body 2, that is softer than the material of the guide body 2. The guide body 2 on the other hand consists of one, in comparison or difference to the cushion body 3, more rigid and harder material.

When used as intended, the attachment 1 or the arrangement with the cushion body 3 is applied to the sample surface 10 to be measured and applied with appropriate pressure. The cushion body 3 should as far as possible adapt to the shape or structure or the profile of the surface. Trapped air between Sample 10 and Cushion Body 3 should be excluded where possible, as they affect image quality. After the measurement, the cushion body 3 either remains in shape as a function of the material and adapts to the new surface only at the next measurement, or is sufficiently elastic that it returns to a neutral shape or its initial position.

The guide body 2 and the cushion body 3 are each formed as a single coherent body, or the guide body 2 and the cushion body 3 are each formed hole-free or respectively free from, their Lichtein- and -austrittsflächen 4,6,30,31 connecting, through recesses. The area between the light inlet and outlet surfaces 4,6,30,31 is thus completely filled with material. The light entry and exit surfaces 4,6,30,31 are each formed as simply connected surfaces.

The attachment 1 or the guide body 2 and the cushion body 3 are each in one piece or in one piece and rotationally symmetrical.

The cushion body 3 or the light entry surface 30 of the cushion body 3 is wholly or full contact with the light exit surface 4 of the guide body 2 and covers the entire light exit surface 4 of the guide body 2. This is a wrinkling or deformation during assembly of the guide body 2 with the cushion body 3 prevents and disturbing air inclusions are almost excluded. Such a recess can be achieved for example by molding or casting over a template or form or by casting or molding directly on or on the guide body 2. Thus, the cushion body 3 is positively and materially adapted to the guide body 2 and connected thereto.

The compound of the cushion body 3 with the guide body 2 on the one hand by direct molding or by, in particular largely refraction-free, bonding with a transparent, optically clear adhesive, which preferably has a refractive index between the refractive indices of the material of the cushion body 3 and Guide body 2 is done, and it may be sufficient if not glued over the entire surface, but only at a few, in particular four, places in the edge region, a bond takes place. It may also be sufficient that the cushion body 3 is pressed only on the lower part 12 and the adhesion is large enough that the cushion body 3 remains in its position.

The article has the following possibilities to be able to use the article in the best possible way: The article has a light-gathering or focusing effect if the material of the guide body 2 has a higher refractive index than the material of the cushion body 3 and the light exit surface 4 of the guide body 2 is convexly curved or when the material of the guide body 2 has a lower refractive index than the material of the cushion body 3 and the light exit surface 4 of the guide body 2 is concavely curved.

The article acts lichtzerstreuend when the material of the guide body 2 has a higher refractive index than the material of the cushion body 3 and the light exit surface 4 of the guide body 2 is concavely curved or if the material of the guide body 2 has a lower refractive index than the material of the cushion body. 3 has and the light exit surface 4 of the guide body 2 is convexly curved.

The way in which the attachment acts on the light or scatters or bundles the light is thus dependent, on the one hand, on which refractive index is greater, but also on the quantitative ratio of the refractive indices to one another.

In Fig. 1, an article 1 is shown with a guide body 2 in the form of a spherical plano-convex lens in which the optically active light exit surface 4 of the guide body 2 is spherically convex curved or curved. The light exit surface 4 has a positive radius of curvature on the incident surface. The cushion body 3 is designed as a corresponding oppositely curved plano-concave lens or the light entry surface 30 of the cushion body 3 is configured in accordance with the light exit surface 4 of the guide body 2 inversely or curved.

In Fig. 2, an article 1 is shown with a guide body 2 in the form of an aspherical plano-convex lens, in which the light exit surface 4 of the guide body 2 is convexly convex arched or curved. The light entrance surface 30 of the cushion body 3 is correspondingly inversely curved to the light exit surface 4 of the guide body 2. In this way, any aberrations and distortions at the edge of the image can be reduced.

In Fig. 1 and Fig. 2, the material of the guide body 2 each has a higher refractive index than the material of the cushion body 3. The lighting or the light source 21 is in each case arranged to the left of the guide body 2 (see Fig. 5). The light In these two embodiments, the light emanating from the light source 21 is thus focused or refracted towards the optical central axis 14, whereby the brightness in this central area is increased. Thus, it is avoided, for example, that in the central measuring region of the sample surface 10 there is partial under-illumination, shading or shadow formation, in particular by the detection unit or the camera 15. Thus, the sample surface 10 is substantially uniformly illuminated over the entire area and is virtually free of camera shadowing. Other types of convex lenses or converging lenses, for example biconvex or concave-convex embodiments, would also be possible.

In Fig. 3 is an essay 1 with a guide body 2 in the form of a spherical plano-concave 4/10 Austrian paientamt AT 506 688 B1 2009-11-15

Lens shown, in which the optically active light-emitting surface 4 of the guide body 2 is spherically concave curved or curved. The light exit surface 4 has a negative radius of curvature on the incident surface. The cushion body 3 is designed as corresponding oppositely curved plano-convex lens or the light entry surface 30 of the cushion body 3 is configured corresponding to the light exit surface 4 of the guide body 2 inversely or curved.

4, an attachment 1 is shown with a guide body 2 in the form of an aspherical plano-concave lens, in which the light exit surface 4 of the guide body 2 is concave curved or aspheric concave. The light entrance surface 30 of the cushion body 3 is correspondingly inversely curved to the light exit surface 4 of the guide body 2. In this way, any aberrations and distortions at the edge of the image can be reduced.

In Fig. 3 and Fig. 4, the material of the guide body 2 also each has a higher refractive index than the material of the cushion body. 3

In these two embodiments, the outgoing from the left next to the guide body 2 light source 21 (see Fig. 5) outgoing light is thus scattered or broken away from the central axis 14, whereby a homogeneous illumination or uniform illumination of the entire surface 10th can be achieved. Other types of concave lenses or diverging lenses would also be possible, for example biconcave or convex-concave configurations.

A concrete advantageous embodiment of an article is manufactured according to FIG. 3 and comprises a correspondingly as in Fig. 3 spherically plano-concave shaped guide body 2, which is machined from cast clear PMMA. The radius of curvature of the light exit surface 4 is 15 mm, the diameter of the guide body 2 is 16.5 mm, the distance between the light entrance surface 6 and the light exit surface 4, measured at the edge, is 16 mm. The cushion body 3 is made of crystal-clear silicone or silicone rubber or silicone rubber with a Shore A hardness of 10-20. The cushion body 3 rests with its light entry surface 30 directly on the light exit surface 4 of the guide body, any type of adhesive is not used. The cushion body 3 can be reversibly removed and it can also be placed at any time a new cushion body 3. The radius of curvature of the light entry surface 30 is also 15 mm, the diameter of the cushion body 3 is 16.5 mm, the distance between the light entry surface 30 and the light exit surface 31, measured at the edge, is 3 mm. The refractive index of PMMA is about 1.5, the refractive index of the silicone rubber is lower. Accordingly, and because of the design of the active surface of such an essay acts light scattering and causes a homogeneous illumination of the sample surface 10. As a camera 15 is in the present case, a camera with an opening angle of about 60 ° and a focal distance of about 15 mm advantageous the illumination or light source 21 is arranged concentrically around the optics of the camera.

In order to prevent spherical aberrations, it is also possible to use guide bodies in the form of paraboloid or with a parabolic exit surface 4, which focus the light in one focal point.

1 and 5, the relative positioning or alignment of the attachment 1 and the detection unit 15 and the light source 21 and the entire arrangement with respect to the sample surface 10 to be measured can be seen.

The exact configuration of the article is also dependent on the design of the illumination.

The guide body 2 and / or the cushion body 3 may be designed as a disposable article for single use or be washable or sterilized and thus reusable. It is also possible to replace only the cushion body 3 and set up before each measurement a, for example, fixed with pressure-sensitive adhesive, new cushion body 3 on the guide body 2.

It is advantageous, in particular in plano-convex guide bodies 2, when the refractive index of the guide body 2 is greater than the refractive index of the cushion body 3. As a result, 21 outgoing light rays from the light source, the transition from the guide body 2 to the cushion body 3 in the direction of the central axis 14th , so broken to the center. This is a shadowing of the 5/10 Austrian Patent Office AT 506 688 B1 2009-11-15

Central area additionally reduced.

The light beams of the light source 21 either pass directly from the light source 21 through the guide body 2 or they are held on the side walls or lateral surfaces of the guide body 2 by total reflection in the interior of the guide body 2. Also, optionally unilateral, inwardly facing, mirroring of the lateral surfaces of the guide body 2 is possible.

The light emanating from the illumination device or light source 21 or the light radiated from the surface 10, for example reflected or scattered light, thus becomes exclusively through both the cushion body 3 and the guide body 2 and thus inside the guide body 2 and the cushion body 3 out.

The cushion body 3, according to an alternative, not shown embodiment, also be formed as a transparent, preferably colorless and / or optically clear, hollow body whose, preferably very thin, shell of a deformable, flexible and / or elastic material or a film, for example of silicone or a silicone derivative or polyurethane, is formed, and with a transparent, preferably homogeneous, colorless and / or optically clear, medium, eg a liquid or a gel, in particular water, saline etc. is filled. If the cushion body 3 is formed as a filled hollow body, the filling of a medium with a refractive index lower than that of the guide body 2, the light rays are also refracted towards the center.

As can be seen from FIG. 6, a carrier part 13 can be fastened or clamped in the region of the light entry surface 6 of the guide body 2. One possibility for attachment and fixation is the formation of a notch or groove 20 in the sample surface 10 remote part of the guide body 2, which advantageously rotates around the entire circumference of the guide body 2. On or in this support member 13, a plurality of devices can be attached or housed, such as a lens 19, the light source 21, the detection unit 15, in particular an intraoral camera, a handle 16, etc.

The diffusing screen 19 is provided in FIG. 6 at or in front of the light entry surface 6 of the guide body 2, between the light source 21 and the light entry surface 6, and can either be glued or placed onto the light entry surface 6, or it is on or ., Fixed in the carrier part 13. The diffusing screen 19 may be a prismatic film or an optical lighting film. Through them, the light of the light source 21 is scattered and diffused.

The light source 21 is arranged centrally or annularly in FIG. 6 around the center axis 14 of the guide body or in front of the light entry surface 6. The light source 21 may consist of a plurality of individual light sources, in particular light-emitting diodes (LEDs), or it may be formed by a luminous disk or surface.

At or in front of the light entry surface 6, the detection unit 15 is provided. The term detection unit 15 is understood to mean an image-capturing and / or image-producing or image-yielding device, in particular a video camera, for example an intraoral camera, or a CCD chip. The detection unit 15 is advantageously arranged centrally or centrally symmetrically to the central axis 14 or in the region of the support member 13. An advantageous arrangement for achieving a good illumination according to FIG. 6 is that the central detection unit 15 is surrounded in a circular ring by the light source 21.

On the support member 13, a handle 16 is attached, wherein the handle 16 is either fixedly connected to the support member 13 and easily up and plugged or -klippbar. The light source 21 and / or the detection unit 15 can be integrated in a gripping head 18, if possible in the handle 16, in particular in the inserted into the support member 13 or plugged onto this. In the event that a light source 21 is plugged onto the attachment 1, a recess 17 may be formed in the carrier part 13, through which the guide body 2 is in optical line connection with the detection unit 15 and / or the light source 21.

It is also possible that the detection unit 15 and / or the light source 21 are external devices which are in active or light-conducting connection with the light guide body 2 via a mirror system or light guide system arranged in the interior of the handle 16. Also optical fibers, e.g. Glass 6/10

Claims (13)

Austrian Patent Office AT 506 688 B1 2009-11-15 fiber leads, which conduct the light from an external light source 21 in the essay 1 and the guide body 2, are conceivable. The light used of the light source 21 is preferably white light, but it can also UV light and / or light other selected wavelengths or areas are used. 1. Attachment for a device for the optical detection of surfaces (10), in particular tooth surfaces, for example for an intraoral camera, wherein the attachment (1) has a transparent or translucent, preferably homogeneous, colorless and / or optically clear, guide body (2) , with a, in particular substantially plan, light entry surface (6) and a light exit surface (4), and on the guide body (2) or on the light exit surface (4) of the guide body (2) form and optionally material fit adjacent, transparent or translucent, preferably homogeneous, colorless and / or optically clear, cushion body (3) having a light entry surface (30) and a, in particular substantially planar, light exit surface (31), wherein the from a lighting device or light source (21) outgoing and / or the light emitted by the surface (10), for example reflected or scattered, through the light Cushion body (3) and the guide body (2) through or inside the guide body (2) and the cushion body (3) is guided, wherein the cushion body (3) preferably consists of such a material or is formed such that the Cushion body (3), in particular reversible, to the shape, structure or to adapt to the profile of the surface to be detected (10), and wherein the guide body (2) of one, in comparison or difference to the cushion body (3), more rigid and harder material, wherein the material of the guide body (2) and the material of the cushion body (3) have different refractive indices or refractive indices, characterized in that the light exit surface (4) of the guide body (2) is concavely or convexly curved. 2. Attachment according to claim 1, characterized in that the light exit surface (4) of the guide body (2) is curved spherically, aspherically or paraboloidally. 3. Attachment according to claim 1 or 2, characterized in that the light entry surface (30) of the cushion body (3) to the light exit surface (4) of the guide body (2) is configured correspondingly inversely or curved or that the cushion body (3) or the light entrance surface (30) of the cushion body (3) touching the light exit surface (4) of the guide body (2) touches or covers the entire light exit surface (4) of the guide body (2), wherein the cushion body (3) and the guide body (2) is bonded in particular by bonding to a transparent, optically clear adhesive, which preferably has a refractive index lying between the refractive indices of the material of the cushion body (3) and the guide body (2). 4. Attachment according to one of the preceding claims, characterized in that the guide body (2) is designed as a plano-concave or plano-convex lens, and the cushion body (3) in particular as corresponding inversely curved plano-convex or plano-concave lens. 5. Attachment according to one of the preceding claims, characterized in that the attachment (1) or the guide body (2) and the cushion body (3) each formed in one piece or in one piece and / or are rotationally symmetrical and / or have the same diameter. 6. Attachment according to one of the preceding claims, characterized in that the guide body (2) and the cushion body (3) are each formed as a single coherent body, or that the guide body (2) and the cushion body (3) are each formed without holes or that the guide body (2) and the cushion body are each free from, the Lichtein- and -austrittsflächen (4,6,30,31) connecting, continuous recesses, and / or that the area between the Lichtein- and -austrittsflächen (4,6,30,31) is completely filled with material and / or that the light entry and exit surfaces (4,6,30,31) are each formed as simply connected surfaces. 7. Attachment according to one of the preceding claims, characterized in that the guide body (2) is designed as solid solid body and made of glass or plastic, preferably polymethylmethacrylate, polycarbonate, polyamide, Styrene-acrylonitrile (SAN), polystyrene, casting compounds or casting resins based on epoxy resin, polyurethane resin, organopolysiloxane or the like, in particular having a ball-pressure hardness of> 100 measured according to ISO 2039-1, and / or that of Pillow body (3) is designed as a solid solid body and made of a deformable, flexible and / or elastic, preferably elastomeric, material, in particular silicone or a silicone derivative, eg Silicone rubber made of soft PVC, etc. having a Shore A hardness of &lt; 40, in particular from 10 to 20, exists. 8. Attachment according to one of the preceding claims, characterized in that the material of the guide body (2) has a higher refractive index than the material of the cushion body (3) and the light exit surface (4) of the guide body (2) is convex or concave curved or that the material of the guide body (2) has a lower refractive index than the material of the cushion body (3) and the light exit surface (4) of the guide body (2) is curved convexly or concavely. 9. Arrangement in the form of a lighting device or a device for detecting or detecting surface features, in particular colors, structures, etc., in particular in the form of an intraoral camera, comprising at least one light source (21) and / or at least one detection unit (15) an attachment according to one of claims 1 to 8. 10. Arrangement according to claim 9, characterized in that the attachment (1), in particular on the guide body (2), preferably in a circumferentially circumferential notch or groove (20) of the guide body (2), a support member (13) for holding or Handling or for fastening components, such as the light source (21) and / or a detection unit (15), is attached or clamped. 11. Arrangement according to claim 9 or 10, characterized in that on or in front of the light entry surface (6) of the guide body (2) one, in particular on the support part (13) or on the guide body (2) fixed, lens (19), preferably between the light entry surface (6) and the light source (21) is provided. Arrangement according to one of Claims 9 to 11, characterized in that the light source (21), e.g. Light emitting diodes, on or in front of the light entry surface (6) of the guide body (2), in particular centrally or annularly around the central axis (14) of the guide body (2) around, in particular on the support part (13) attached arranged. 13. Arrangement according to one of claims 9 to 12, characterized in that the detection unit (15), in particular an image capturing and / or generating and / or -weitner device, in particular a video camera, such as an intraoral camera, or a CCD chip, a CMOS image sensor, a photodiode array, etc., on or in front of the light entry surface (6) of the guide body (2), in particular centrally or centrally symmetrically to the central axis (14), in particular on the support member (13) attached, is arranged advantageously the detection unit (15) is surrounded annularly by the light source (21) or the detection unit (15) and the light source (21) are arranged concentrically. For this 2 sheet drawings 8/10