JP4013966B2 - Lens polishing method - Google Patents

Description

  The present invention relates to a polishing method for polishing an optical surface of an optical element such as a lens, and more particularly to a polishing method suitable for an aspherical lens.

  Conventionally, a concave surface such as a spectacle lens is formed into a shape such as a spherical surface, a rotationally symmetric aspherical surface, a toric surface, a progressive surface, or a curved surface obtained by combining these by cutting or the like, and finally the optical surface is mirror-polished. For mirror polishing of a simple curved surface such as a spherical surface or a toric surface, rubbing polishing using a rigid polishing dish is used. The mirror polishing method using a polishing dish is a method of transferring the surface shape of the polishing dish to the surface to be polished, and therefore requires as many processing dishes as the number of surface shapes corresponding to the prescription, and the number is several thousand. .

In addition, for polishing a complicated curved surface such as a progressive surface, that is, a so-called free curved surface shape, an elastic polishing tool is generally used because it cannot be polished by a polishing method using a rigid polishing dish. .
As a method using an elastic polishing tool, for example, a polishing method using a balloon-type polishing tool has been proposed (see, for example, Patent Document 1). In this polishing method, pressure gas is sent to the inside of the balloon-type polishing tool, the balloon-type polishing tool is inflated with the internal pressure, the curvature is changed by changing the internal pressure, and the curvature matches the curved surface shape of the surface to be polished. Since it can follow the curvature of the concave surface, one type of balloon-type polishing tool can be used for a plurality of types of surfaces to be polished having different curved shapes.

  Furthermore, a partial polishing method using a small dome-shaped elastic polishing tool that contacts a part of the surface to be polished is known (for example, see Patent Document 2). This polishing method is a method for polishing the entire surface to be polished by connecting local polishing with a small elastic polishing tool.

JP 2003-275949 A JP 2000-317797 A

Conventionally, most of spectacle lenses after polishing before being put into a spectacle frame have a circular outer shape. In recent years, however, spectacle lenses have been made thinner and processed so that the thinnest center thickness can be obtained from spectacle frame data and prescriptions. Therefore, the outer shape of the lens is almost elliptical (non-circular) and the edges are sharp. The production of eyeglass lenses has been increasing.
However, in the polishing method using the balloon-type polishing tool proposed in Patent Document 1, the polishing time is short because the entire surface to be polished is applied with the balloon-type polishing tool. When polishing a lens with a sharp part, the edge of the lens bites into the polishing pad attached to the balloon polishing part and the polishing pad is peeled off, or the lens or polishing tool to be polished is damaged. There is. In order to prevent this, if the internal pressure of the balloon polishing part is increased, the flexibility is lost and the followability to the shape is deteriorated, and a non-polished range or polishing unevenness may occur.

  On the other hand, in the partial polishing method using the elastic polishing tool proposed in Patent Document 2, the entire surface is polished by moving the elastic polishing tool over the entire surface to be polished. Therefore, since the elastic body can change the shape following the surface to be polished at the portion in contact with the surface to be polished, the polishing unevenness is to be applied to the surface to be polished having a circular lens outer shape and a large amount of aspheric surface. However, when the lens outer shape is substantially elliptical, it contacts the elastic polishing tool intermittently, so when polishing a lens with sharp edges, the edge of the lens bites into the polishing pad, and the polishing pad There are problems such as peeling off or damaging a lens or polishing tool to be polished.

  Therefore, the present invention has been made in view of such circumstances, and when polishing the optical surface of an optical element such as a lens, the polishing pad is prevented from peeling off, and unnecessary scratches are caused on the surface to be polished. It aims at providing the grinding | polishing method which can grind | polish without attaching.

  In order to solve the above-described problems, the lens polishing method of the present invention is an elastic polishing having an outer diameter smaller than the outermost diameter of the lens on the surface to be polished of the lens having a substantially elliptical outer periphery. In the method of polishing a lens that abuts a tool and rotates the lens and the elastic polishing tool while rotating the lens and / or the lens while oscillating the lens, the elastic polishing moves relative to the lens. The movement range of the rotation center of the tool is within the shortest diameter of the substantially elliptical shape.

  According to this, an elastic polishing tool having an outer diameter smaller than the outermost diameter of the lens is brought into contact with the surface to be polished of the lens having a substantially elliptical outer contour, and the lens and the elastic polishing tool are rotated. However, when the elastic polishing tool and / or the lens is swung and polished, the movement range of the rotation center of the elastic polishing tool that moves relative to the lens is within the shortest diameter of the substantially elliptical shape. The edge of the lens with a sharp oval edge bites into the polishing pad affixed to the elastic polishing tool so that the polishing pad does not peel off, and the entire polished surface of the lens is not polished or scratched. A mirror surface with no occurrence is obtained. The substantially elliptical shape is a non-circular shape including at least an arc in the outline of the outer peripheral portion, such as an oval shape, an oval shape, a so-called oval shape such as an elliptical shape for track competitions, and the like.

In the lens polishing method of the present invention, the outer diameter of the elastic polishing tool is a value represented by “the outer diameter of the elastic polishing tool ≧ (the outermost diameter of the lens−the shortest diameter of the lens)”. It is characterized by being.
According to this, the outer diameter of the elastic polishing tool is a value expressed by “the outer diameter of the elastic polishing tool ≧ (the outermost diameter of the lens−the shortest diameter of the lens)” and moves relative to the lens. The movement range of the elastic polishing tool is within the shortest diameter of the substantially elliptical lens, so that even if the lens has a substantially elliptical shape and the edge is a sharp edge, polishing applied to the elastic polishing tool The mirror surface does not bite into the pad, and thus the polishing pad is not peeled off, and the entire polished surface of the lens is free from polishing residue and polishing scratches.

In the lens polishing method of the present invention, the movement range of the rotation center of the elastic polishing tool relative to the lens, that is, the circular region drawn by the rotation center of the elastic polishing tool moving relative to the lens is in contact with the lens. It moves within the range from the rotation center to the shortest position of the contour of the outer periphery.
According to this, the movement range of the rotation center of the elastic polishing tool with respect to the substantially elliptical lens, that is, the circular area drawn by the relative movement of the rotation center of the elastic polishing tool contacting the lens is from the rotation center of the lens. By moving within the range up to the shortest position of the contour of the outer periphery, the moving range of the elastic polishing tool is within the shortest diameter of the elliptical shape, the lens is almost elliptical, and the edge is a sharp edge However, it does not bite into the polishing pad attached to the elastic polishing tool, and thus the polishing pad is not peeled off, and a mirror surface on which the entire polished surface of the lens is free from polishing residue and scratches is obtained.

  The lens polishing method of the present invention includes a step of calculating a lens surface shape and a lens outer shape, a step of generating a surface to be polished based on the calculated surface shape and outer shape, and a shape generation. And a step of polishing the surface to be polished.

  According to this, the surface shape of the lens and the outer shape of the lens are calculated, and the surface to be polished is created and polished based on the calculated surface shape and outer shape, so that the outer peripheral edge portion of the lens is referred to as a burr. This results in a lens that does not generate the wavy phenomenon, and even if the shape is created and the outer shape is almost elliptical, and the edge is a sharp edge, the lens bites into the polishing pad attached to the elastic polishing tool. As a result, the entire surface of the lens to be polished is not peeled off, and a mirror surface free from polishing residue and scratches can be obtained.

If burrs are generated after the creation of the lens shape, it is necessary to chamfer.
Therefore, the lens polishing method of the present invention is characterized in that the contour thickness of the outer peripheral portion after the creation of the shape of the surface to be polished is larger than zero (0) and has an outer shape with a value in the range of 2 mm. To do.
When the thickness of the contour of the outer peripheral portion after the creation of the shape of the surface to be polished is zero (0), burrs are easily generated. Therefore, in order to prevent the generation of burrs, it is effective to make the thickness of the contour of the outer peripheral portion after the creation of the shape of the surface to be polished larger than zero (0). Further, if the outer shape is formed until the thickness of the contour of the outer peripheral portion after the creation of the shape of the surface to be polished exceeds 2 mm, it is formed smaller than the frame shape, that is, the lens insertion shape of the spectacle frame. It is effective that the thickness of the contour of the outer peripheral portion after shape creation is within 2 mm.

  That is, the thickness of the contour of the outer peripheral portion after the creation of the shape of the surface to be polished is larger than zero and the outer shape has a value in the range of 2 mm, so that the lens is less likely to be scratched after polishing the surface to be polished, etc. When the surface treatment is performed, it is possible to prevent the processing liquid from being accumulated due to burrs on the outer peripheral edge of the lens, and the outer peripheral edge is elastic due to the outer peripheral burrs when the surface to be polished is polished. Biting into the polishing tool can be prevented.

  The polishing method of the present invention can be applied to an optical lens or the like. Of these, a glass mold with optical properties is used on either the convex or concave side of the lens, and a semi-finished lens (semi-finished lens) with optical properties on only one side is molded by a curing reaction. It can be preferably used for a spectacle lens or the like that forms a predetermined optical characteristic by cutting, grinding, or polishing the non-surface side (generally, the concave surface side).

Since the semi-finished lens needs to be processed into a desired lens by polishing or the like, the entire lens is formed with a large thickness. In general, after molding, the outer shape of the lens is molded in a circular shape. However, when cutting or the like is performed so that the thinnest center thickness can be obtained from the spectacle frame data and prescription, the outer shape of the lens becomes substantially elliptical. There is a case. The edge of the substantially elliptical shape is a sharp edge, and becomes more noticeable when the length of the short side of the substantially elliptical shape is small. In addition, as for the size of the semi-finished lens, a size having an outer diameter (outermost diameter) of about 40 to 80 mm is generally used.
The lens that has been polished to obtain the predetermined optical characteristics and surface-treated to make the lens less likely to be scratched is subjected to edge processing in accordance with the shape of the inner periphery of the spectacle frame. Etc. are performed, and it is inserted into the spectacle frame to complete the spectacles.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
First, the elastic polishing tool 1 used in the present invention will be described with reference to FIGS. 1 and 2.
Fig.1 (a) is sectional drawing of an elastic polishing tool, The same figure (b) is a top view. FIG. 2 is a schematic cross-sectional view of the elastic polishing body.

  The elastic polishing tool 1 includes a polishing body substrate 2, an elastic polishing body 3, and a polishing pad 4. The elastic polishing body 3 is attached to the upper surface of the polishing body substrate 2, and the polishing pad 4 is further mounted on the upper surface of the elastic polishing body 3. Is attached. The elastic polishing tool 1 is mounted on a polishing shaft of a polishing apparatus and rotates to polish the aspherical shape of the spectacle lens 5 (surface 5a to be polished, see FIG. 3). The diameter of the elastic polishing tool 1 is set smaller than the outermost diameter of the spectacle lens 5 in order to polish without breaking the aspherical shape of the spectacle lens 5.

  The abrasive base material 2 is made of a relatively hard material such as a metal or a hard plastic resin, and is formed in a cylindrical shape with a collar. The polishing body base 2 is attached to a polishing shaft of a polishing apparatus (not shown) with a collar portion centered on a cylindrical central axis, and the elastic polishing body 3 is attached to the other cylindrical surface (upper surface).

  The elastic polishing body 3 is formed of an elastic material that can change its shape following the surface to be polished 5a of the object to be polished (eyeglass lens 5), for example, silicon rubber, and has a cylindrical shape as shown in FIG. A dome-shaped curved surface 31 having a predetermined radius of curvature R close to the polished surface shape of the object to be polished (glass lens 5) is formed on one surface of the substrate, and the other surface has a cylindrical central axis as the polishing body substrate 2 Is attached to the upper surface of the abrasive base material 2 by an adhesive, for example. In order to perform this attachment easily, for example, the diameter c (see FIG. 2) of the elastic abrasive body 3 and the cylindrical diameter of the abrasive body base material 2 are preferably set to the same dimension.

  In addition to silicon rubber, the elastic abrasive 3 is made of natural rubber, nitrile rubber, chloroprene rubber, styrene-butadiene rubber (SBR), acrylonitrile-butadiene rubber (NBR), rubber such as fluorine rubber, polyethylene, Mention may be made of thermoplastic resins such as nylon and thermoplastic resin elastomers such as styrene and urethane.

  This elastic polishing body 3 is prepared in many types with different curvatures of the curved surface 31. When polishing the inner surface (concave surface) of the spectacle lens 5, for example, an elastic polishing body 3 having a curvature radius R (see FIG. 2) of 35 mm to 600 mm is prepared. When the radius of curvature R is in the range of 35 to 200 mm, 5 to 10 mm increments, preferably 10 to 30 mm in increments of 5 to 10 types, and in the range of curvature radius R of 200 to 600 mm, several types are prepared in increments of 100 to 200 mm. Thereby, it can respond to the curved surface of the concave surface (surface 5a to be polished) of the spectacle lens 5 based on almost all prescriptions.

  The polishing pad 4 is made of a circular nonwoven fabric sheet, and the substantially circular center is attached to the position of the approximately central axis of the curved surface 31 of the elastic polishing body 3 via, for example, a double-sided adhesive tape. Examples of the material of the polishing pad 4 include a sheet formed of a porous material such as felt and polyurethane in addition to a nonwoven fabric, and a sheet of short fibers embedded in a synthetic resin sheet.

Next, a method for polishing the concave surface (surface 5a to be polished) of the spectacle lens 5 using the elastic polishing tool 1 will be described.
FIG. 3 is a schematic side view showing an aspect of polishing an object (glasses lens) using an elastic polishing tool, and FIG. 4 shows a polishing positional relationship between the elastic polishing tool and the object (glasses lens). It is an upper surface schematic diagram.

In FIG. 3, the elastic polishing tool 1 (the flange portion of the polishing body substrate 2) is mounted on a polishing shaft of a polishing apparatus (not shown). The elastic polishing tool 1 attached to the polishing shaft has a radius of curvature smaller than the average radius of curvature of the surface 5a to be polished of the spectacle lens 5 among the curvatures of the curved surface 31 of the elastic polishing body 3 prepared in various types. And the one closest to the radius of curvature of the surface to be polished 5a is selected.
The polishing shaft of the polishing apparatus includes a mechanism that presses the elastic polishing tool 1 against the surface to be polished 5a of the spectacle lens 5 with a predetermined polishing pressure by applying, for example, air pressure. The polishing apparatus also includes a discharge nozzle 8 that supplies a slurry 9 containing an abrasive between the elastic polishing tool 1 and the polished surface 5 a of the spectacle lens 5.

  On the other hand, the spectacle lens 5 as an object to be polished is bonded via a bonding material 6 made of, for example, a low melting point metal or wax, which is bonded to a mounting jig 7 that is mounted and fixed to a chuck of a polishing apparatus (not shown). The surface (convex surface) opposite to the surface 5a to be polished of the spectacle lens 5 is affixed and fixed. Note that the chuck of the polishing apparatus includes a rotation (rotation) mechanism and a swing mechanism by numerical control or the like.

  In the polishing method of the surface 5a to be polished of the spectacle lens 5, first, the polishing shaft of the polishing apparatus is rotationally driven to rotate the elastic polishing tool 1 mounted on the polishing shaft. Then, air pressure is applied to the mechanism that presses the polishing shaft against the surface to be polished 5a, and the elastic polishing tool 1 is pressed against the surface to be polished 5a of the spectacle lens 5 with a predetermined pressure, and the chuck is rotated by the rotation mechanism with a predetermined rotation. The rotating mechanism operates while rotating (spinning) by a number, and the spectacle lens 5 swings on the elastic polishing tool 1 (the surface of the polishing pad 4 attached to the curved surface 31 of the elastic polishing body 3).

Along with the rotation of the chuck and the polishing shaft, a slurry 9 containing an abrasive is supplied from the discharge nozzle 8 between the elastic polishing tool 1 and the surface to be polished 5a, and the surface to be polished 5a of the spectacle lens 5 is polished.
Note that the rotation direction of the polishing shaft (elastic polishing tool 1) and the rotation direction of the chuck (glass lens 5) of the polishing apparatus may be either the same rotation direction or the opposite rotation direction, but they are opposite from the viewpoint of polishing efficiency. The direction of rotation is more preferred.

  For example, 0.01 to 1.00 MPa is applied as the air pressure at which the elastic polishing tool 1 is pressed against the surface 5a to be polished of the spectacle lens 5 by a mechanism for pressing. Moreover, the rotation speed of the elastic polishing tool 1 (polishing shaft) is set in a range of 100 to 1500 rpm, for example, and the rotation speed of the spectacle lens 5 (chuck) is set in a range of 100 to 1500 rpm, for example. The moving movement of the spectacle lens 5 (chuck) that swings is set on the surface 5a to be polished, for example, at 1 to 20 reciprocations / min.

  Next, a method for polishing the spectacle lens 5 will be described with reference to a schematic top view showing a polishing positional relationship between the elastic polishing tool and an object to be polished (glass spectacle lens) in FIG. 4A shows a polished state at the outermost diameter position of the object to be polished, and FIG. 4B shows a state in which the object to be polished is rotated by 90 ° from FIG. The polishing state at the radial position is shown. FIG. 4 shows the relative position of the elastic polishing tool 1 (elastic polishing body 3) with respect to the rotation center O1 of the spectacle lens 5.

The spectacle lens 5 as an object to be polished moves relative to the elastic polishing tool 1 (elastic polishing body 3) when the spectacle lens 5 (chuck of the polishing apparatus) swings.
In FIG. 4A, the spectacle lens 5 is polished in such a manner that the moving distance e from the rotation center O2 of the elastic polishing body 3 and the rotation center O1 of the spectacle lens 5 is substantially elliptical from the rotation center O1 of the spectacle lens 5. Polishing is performed by setting it within 1/2 of the short diameter b (shortest diameter f). That is, polishing is performed with the moving range set within the shortest diameter f. At this time, the diameter c of the elastic polishing body 3 is “a substantially elliptical long diameter a of the spectacle lens 5 (outermost diameter d)> a diameter c of the elastic polishing body 3 ≧ a substantially elliptical long diameter a of the spectacle lens 5 (the maximum). Outer diameter d) —determined based on the substantially elliptical short diameter b (shortest diameter f) of the spectacle lens 5 ”.

The shortest diameter f is the radius from the rotation center O1 of the spectacle lens 5 to the closest position of the outer shape (outer peripheral contour) when the outer shape of the spectacle lens 5 is substantially elliptical. Represents the diameter of the circle. Similarly, the outermost diameter d represents the diameter of a circle whose radius is the length of the outer shape of the spectacle lens 5 from the rotation center O1 to the position farthest from the outer shape.
That is, the polishing method for the spectacle lens 5 is such that the rotational center O2 of the elastic polishing body 3 is not moved from the rotation center O1 of the spectacle lens 5 to the outer diameter closest to the outer shape of the spectacle lens 5 or more. Polishing is performed in a circular region drawn by the rotational center O2 of the lens 3 in contact with the spectacle lens 5.

As an example of this, in FIGS. 4A and 4B, a spectacle lens having a substantially elliptical long diameter a (outermost diameter d) of 60 mm and a short diameter b (shortest diameter f) of 20 mm is polished. In this case, the outer diameter c of the elastic polishing body 3 is smaller than the major axis a of the spectacle lens 5: 60 mm, and the minor axis b of the spectacle lens 5 from the major axis a: 60 mm of the spectacle lens 5 is 20 mm. Using the elastic polishing body 3 in the range of 40 mm having the same size as the subtracted value, the movement distance e of the rotation center O2 of the elastic polishing body 3 from the rotation center O1 of the spectacle lens 5 is approximately elliptical. Polishing is performed by setting the minor axis b to 10 mm within 1/2 of 20 mm. That is, the moving range of the rotation center of the elastic polishing tool that moves relative to the spectacle lens is set to 20 mm.
The elastic polishing body 3 (elastic polishing tool 1) is selected to be smaller than the average radius of curvature of the surface 5a to be polished of the spectacle lens 5 and closest to the radius of curvature of the surface 5a to be polished. Polishing is performed in contact with

Next, a method for setting the dimensions of the outermost diameter d and the shortest diameter f will be described.
FIG. 5A is a schematic top view showing an aspect of a spectacle lens in shape creation, and FIG. 5B is a schematic cross-sectional view of FIG.

  In FIG. 5, a spectacle lens 5 to be polished has a semi-finished lens (semi-finished lens, two in FIG. 5) that has optical characteristics on the convex surface side in advance, and has a circular outer contour (outer shape). The molding surface 50a on the concave surface side 50 (indicated by a dashed line) is cut or ground, and a ground surface 5a having a predetermined aspherical shape (hereinafter referred to as a spherical shape) is created. By cutting in this shape creation process, the outline (outer shape) of the outer peripheral portion of the spectacle lens 5 is changed from a circular shape to, for example, a substantially elliptical shape having a major axis a and a minor axis b.

  When creating a shape, first, using a computer or the like, the surface shape to be created (the shape of the surface to be polished 5a) is calculated based on the prescription. Based on the calculated surface shape and the spectacle frame data, the outer shape of the spectacle lens 5 after the shape creation is calculated. In this outer shape calculation process, the shape of the inner peripheral edge of the spectacle frame indicated by a two-dot chain line in the outer shape of the spectacle lens 5 (that is, the shape to be processed by the lens after polishing the polished surface 5a), and the like The value of the thickness of the center of the lens after creation of the desired shape is also used.

  The calculation process of the outer shape of the spectacle lens 5 is based on the surface shape of which the shape is created, and the outer shape (substantially elliptical shape) of the spectacle lens 5 in which the contour thickness of the outer periphery after the shape creation is zero (0). Calculated. Based on the calculated outer shape, the values of the major axis a (outermost diameter d) and the minor axis b (shortest diameter f) are obtained.

  In addition to the case where the contour thickness of the outer peripheral portion of the spectacle lens 5 is zero in calculating the outer shape, as shown in the partial sectional view of the outer peripheral portion of the spectacle lens in FIG. t is larger than zero (0), and an outer shape at a desired value within a range of about 2 mm is calculated. Based on the calculated outer shape, a long diameter a (outermost diameter d), a short diameter b (shortest diameter) It is preferred to determine the value of f). Then, it is preferable to chamfer such as R chamfering or C chamfering on the outer peripheral edge portion formed by the contour of the outer peripheral portion and the surface 5a to be polished. FIG. 6 shows a case where a chamfered surface r is formed by rounding the outer peripheral edge portion.

By chamfering the outer peripheral edge portion, the surface edge of the spectacle lens 5 (surface 5a to be polished) is subjected to surface treatment such as making the spectacle lens 5 less likely to be scratched after polishing the surface 5a. It is possible to prevent the treatment liquid from being accumulated due to burrs and the like, and to make it difficult for the outer peripheral edge portion to bite into the polishing pad 4 when the surface 5a to be polished is polished. The chamfering process can be performed simultaneously with the shape creation process. The outer peripheral contour thickness t is within the range of the outer peripheral contour thickness of about 2 mm in order to obtain a spectacle lens in which the thickness of the lens central portion in the inner peripheral shape 60 of the spectacle frame is as thin as possible. It is desirable that
Note that the dimensions of the shortest diameter f and the outermost diameter d of the substantially elliptical shape may be obtained by actual measurement after the shape creation.

Then, the value of the diameter c of the elastic polishing body 3 is determined based on the values of the long diameter a (the outermost diameter d) and the short diameter b (the shortest diameter f), and a spectacle lens whose shape has been created by the above-described polishing method. The surface 5a to be polished 5 is polished to form a lens surface having predetermined optical characteristics.
After that, the polished spectacle lens 5 is subjected to surface processing or the like for making the lens surface difficult to be scratched, and then subjected to edging or the like for performing edge trimming in accordance with the shape of the inner peripheral edge of the spectacle frame. , It is fitted into a spectacle frame to complete the spectacles.

  According to this polishing method, the rotation center O2 of the elastic polishing body 3 does not move beyond the minimum diameter of the outer shape of the spectacle lens 5 from the rotation center O1 of the spectacle lens 5, so that the outer peripheral edge portion of the spectacle lens 5 to be polished However, if the polishing pad 4 is peeled off by biting into the polishing pad 4 attached to the surface of the elastic polishing body 3, or the polishing pad 4 is peeled off, the spectacle lens 5 to be polished, the elastic polishing body 3 may be damaged. Can be prevented.

  The elastic polishing body 3 (elastic polishing tool 1) has a radius of curvature smaller than the diameter of the spectacle lens 5 and smaller than the average curvature radius of the polished surface 5a of the spectacle lens 5, and the polished surface 5a. A mirror surface that is less prone to occurrence of polishing unevenness without breaking a predetermined aspherical shape formed in advance by selecting a material having the closest radius of curvature of the material and performing polishing in a state of being in contact with the surface to be polished 5a. Polishing can be performed.

  Further, the surface shape of the spectacle lens 5 and the outer shape of the spectacle lens 5 are calculated, and the surface to be polished 5a is created based on the calculated outer shape and polished, whereby the thickness of the central portion of the spectacle lens 5 is calculated. A thin spectacle lens can be obtained. Further, the calculated outer shape of the spectacle lens 5 is such that the contour thickness of the outer peripheral portion after the creation of the shape of the polished surface 5a is larger than zero and has an outer shape with a value in the range of 2 mm. The outer peripheral edge portion formed by the contour of the outer peripheral portion and the surface to be polished 5a can be chamfered, and the surface of the spectacle lens 5 is less likely to be damaged after the polishing of the polished surface 5a. When processing is performed, it is possible to prevent a pool of processing liquid from being generated at the outer peripheral edge portion of the spectacle lens 5.

  In the above polishing method, for the sake of explanation, the outer peripheral contour (outer shape) has been described using a lens having a substantially elliptical shape. For example, an oval shape such as an oval shape or an oval shape for track competition is used. It may be a shape. In the present invention, the outer shape including these is substantially elliptical.

Moreover, although this embodiment demonstrated the case where the concave surface of the spectacle lens 5 was grind | polished as a to-be-polished surface using the elastic polishing tool 1 in which the dome-shaped curved surface was formed, it is a crater-shaped (concave hole-shaped) curved surface. The present invention can also be applied in the same manner when an object to be polished having a convex surface as a surface to be polished is polished using the elastic polishing tool 1 having the shape.
Moreover, although this embodiment demonstrated the case where a plastic spectacle lens was used, if an to-be-polished object is an optical element which needs smoothing or mirror polishing, it will not be restrict | limited. For example, in addition to plastic spectacle lenses, various optical lenses, glass molds for cast polymerization of plastic lenses, optical lenses made of glass including spectacle lenses, molds for molding optical lenses, etc. Can be applied.

  Examples and comparative examples based on this embodiment will be described below.

Example 1
As an object to be polished, a lens (glass eyeglass lens 5) having a contour (outer shape) of an outer peripheral portion having a substantially elliptical shape and a sharp edge was polished. The length from the rotation center O1 of the spectacle lens 5 to the lens outer periphery measured before polishing was a maximum of 40 mm (that is, the outermost diameter d was 80 mm) and a minimum of 25 mm (that is, the shortest diameter f was 50 mm). The diameter c of the elastic polishing body 3 as the elastic polishing tool 1 is smaller than the outermost diameter d80 mm of the spectacle lens 5 and is less than 30 mm obtained by subtracting the shortest diameter f50 mm of the spectacle lens 5 from the outermost diameter d80 mm of the spectacle lens 5. A large 40 mm elastic polishing body 3 was used.

Then, the rotational distance O2 of the elastic polishing body 3 (elastic polishing tool 1) that moves relative to the spectacle lens 5 and the moving distance e from the rotation center O1 of the spectacle lens 5 are set to the lens outer peripheral portion from the rotation center O1 of the spectacle lens 5. 25 mm (that is, the moving range of the rotation center of the elastic polishing tool that moves relative to the spectacle lens is 50 mm), and the pressure at which the elastic polishing tool 1 is pressed against the surface 5a to be polished of the spectacle lens 5 is set to 0. The rotational speed of 1 MPa and the elastic polishing tool 1 was set to 1400 rpm. Further, the eyeglass lens 5 was moved on the elastic polishing tool 1 at a rate of one reciprocation of 10 rpm for a rotation speed of 500 rpm and polished for 2 minutes.
The polished spectacle lens 5 does not peel off the polishing pad 4 affixed to the elastic polishing body 3, and the entire surface of the surface 5a to be polished has a mirror surface free from polishing residue and scratches. Desired appearance quality was obtained.

(Example 2)
A circular semi-finished lens (eyeglass lens 5) having an outer diameter of 70 mm was prepared as an object to be polished, and shape creation and polishing were performed. First, at the stage of calculating the aspherical shape of the spectacle lens 5 before polishing, the outer shape of the lens after shape creation (cutting) was calculated. The calculated outer shape is a substantially elliptical shape in which the length from the rotation center O1 of the spectacle lens 5 to the lens outer peripheral portion is a maximum of 30 mm (that is, the outermost diameter d is 60 mm) and a minimum is 15 mm (that is, the shortest diameter f is 30 mm). The outer shape was sharp at the edges. The diameter c of the elastic polishing body 3 as the elastic polishing tool 1 is smaller than the outermost diameter d: 60 mm of the spectacle lens 5 and the shortest diameter f: 30 mm of the spectacle lens 5 from the outermost diameter d: 60 mm of the spectacle lens 5. A 40 mm elastic polishing body 3 larger than the subtracted value 30 mm was used.

Then, the rotational distance O2 of the elastic polishing tool 1 (elastic polishing body 3) that moves relative to the spectacle lens 5 and the movement distance e from the rotation center O1 of the spectacle lens 5 are determined from the rotation center O1 of the spectacle lens 5 to the outer periphery of the lens. 15 mm (that is, the moving range of the rotation center of the elastic polishing tool that moves relative to the spectacle lens is 30 mm), and the pressure at which the elastic polishing tool 1 is pressed against the surface to be polished 5 a of the spectacle lens 5 is set to 0. The rotational speed of 1 MPa and the elastic polishing tool 1 was set to 1400 rpm. Further, the eyeglass lens 5 was moved on the elastic polishing tool 1 at a rate of one reciprocation of 10 rpm for a rotation speed of 500 rpm and polished for 2 minutes.
The polished spectacle lens 5 does not peel off the polishing pad 4 affixed to the elastic polishing body 3, and the entire surface of the surface 5a to be polished has a mirror surface free from polishing residue and scratches. Desired appearance quality was obtained.

(Example 3)
A circular semi-finished lens 50 having an outer diameter of 70 mm was prepared as an object to be polished, and shape creation and polishing were performed. First, in the stage of calculating the surface shape of the spectacle lens 5, the surface shape was calculated, and the outer shape was calculated by setting the thickness t of the contour of the spectacle lens 5 to be created to 2.0 mm. The calculated outer shape is a substantially elliptical shape in which the length from the rotation center O1 of the spectacle lens 5 to the lens outer peripheral portion is a maximum of 30 mm (that is, the outermost diameter d is 60 mm) and a minimum is 14 mm (that is, the shortest diameter f is 28 mm). Met. Cutting was performed based on the calculated surface shape and outer shape of the spectacle lens 5. In addition, R chamfering was performed on the outer peripheral edge portion to form a chamfered surface r having a curvature radius of 1.0 mm.

  The diameter c of the elastic polishing body 3 as the elastic polishing tool 1 is smaller than the outermost diameter d of the spectacle lens 5: 60 mm, and the shortest diameter f of the spectacle lens 5 is 28 mm from the outermost diameter d of the spectacle lens 5. A 40 mm elastic polishing body 3 larger than the subtracted value 32 mm was used.

Then, the rotational distance O2 of the elastic polishing tool 1 (elastic polishing body 3) that moves relative to the spectacle lens 5 and the movement distance e from the rotation center O1 of the spectacle lens 5 are determined from the rotation center O1 of the spectacle lens 5 to the outer periphery of the lens. 14 mm (that is, the moving range of the rotation center of the elastic polishing tool that moves relative to the spectacle lens is 28 mm), and the pressure at which the elastic polishing tool 1 is pressed against the surface 5a to be polished of the spectacle lens 5 is set to 0. The rotational speed of 1 MPa and the elastic polishing tool 1 was set to 1400 rpm. Further, the eyeglass lens 5 was moved on the elastic polishing tool 1 at a rate of one reciprocation of 10 rpm for a rotation speed of 500 rpm and polished for 2 minutes.
The polished spectacle lens 5 does not peel off the polishing pad 4 affixed to the elastic polishing body 3, and the entire surface of the surface 5a to be polished has a mirror surface free from polishing residue and scratches. Desired appearance quality was obtained.

(Comparative Example 1)
As an object to be polished, a lens (glasses lens 5) having the same outer peripheral contour (outer shape) as in Example 1 and a sharp edge was prepared. The moving distance e of the elastic polishing tool 1 that moves relative to the spectacle lens 5 is set to 40 mm (that is, the elastic polishing tool that moves relative to the spectacle lens relative to the minimum length of 25 mm from the rotation center O1 to the lens outer peripheral portion). The spectacle lens 5 was polished under the same polishing conditions as in Example 1, except that the movement range of the rotation center of the lens was set to 80 mm, which was the same as the outermost diameter d of the spectacle lens.
However, immediately after the polishing is started, the edge portion of the lens whose outer shape is substantially elliptical and has a sharp edge bites into the polishing pad 4 attached to the elastic polishing body 3, and damages the lens and the elastic polishing tool 1. As a result, the spectacle lens 5 was defective.

(Comparative Example 2)
A circular semi-finished lens (glass lens 5) having an outer diameter of 70 mm, which was the same as that used in Example 2, was prepared as an object to be polished. Then, the moving distance e of the rotational center O1 of the elastic polishing tool 1 that moves relative to the spectacle lens 5 is 30 mm (that is, relative to the spectacle lens) that is larger than the minimum length of 15 mm from the rotational center O1 to the lens outer peripheral portion. The spectacle lens 5 was polished under the same polishing conditions as in Example 2 except that the movement range of the rotation center of the elastic polishing tool to be performed was 60 mm, which was the same as the outermost diameter d of the spectacle lens.
However, immediately after the polishing is started, the edge portion of the lens whose outer shape is substantially elliptical and has a sharp edge bites into the polishing pad 4 attached to the elastic polishing body 3, and damages the lens and the elastic polishing tool 1. As a result, the spectacle lens 5 was defective.

  From the results of the above examples and comparative examples, the diameter c of the elastic polishing tool 1 (elastic polishing body 3) that moves relative to the spectacle lens 5 is expressed as “the outermost diameter d of the spectacle lens 5 being substantially elliptical> The diameter of the elastic polishing body 3 is equal to or greater than the outermost diameter d of the spectacle lens 5 and the shortest diameter f of the spectacle lens 5. The moving distance of the rotational center O2 of the elastic polishing body 3 By performing polishing by setting e to a value within the length from the rotation center O1 of the spectacle lens 5 to the closest position of the outer shape (outer peripheral contour) (that is, the moving range is within the shortest diameter f). Thus, the polishing pad 4 attached to the elastic polishing body 3 is not peeled off, and a mirror surface on which the entire polishing surface 5a is free from polishing residue and scratches is obtained (Examples 1, 2 and 3).

  On the other hand, despite the use of the same elastic polishing body 3 as in Example 1 and Example 2, the moving distance e of the rotation center O2 of the elastic polishing tool 1 that moves relative to the spectacle lens 5 is the rotation of the spectacle lens 5. When the length was set to be greater than the minimum length from the center O1 to the outer periphery of the lens, the edge portion of the lens having the outer shape of the spectacle lens 5 having a substantially elliptical shape and a sharp edge was attached to the elastic polishing body 3. The spectacle lens 5 and the elastic polishing tool 1 are damaged by biting into the polishing pad 4, and the predetermined spectacle lens 5 cannot be obtained (Comparative Examples 1 and 2).

(A) is sectional drawing of the elastic polishing tool of this invention, (b) is a top view of the elastic polishing tool of this invention. The schematic cross section of an elastic polishing body. The schematic side view which shows the aspect which grind | polishes a to-be-polished object using the elastic polishing tool of this invention. It is an upper surface schematic diagram which shows the polishing positional relationship of an elastic polishing tool and a to-be-polished object, (a) shows the grinding | polishing state of the outermost diameter position of a to-be-polished object, (b) is 90 to 90 to a to-be-polished object. ° Indicates rotated state. (A) is an upper surface schematic diagram which shows the aspect of the spectacle lens in shape creation. (B) is a cross-sectional schematic diagram of (a). The fragmentary sectional view of the outer peripheral part of a spectacle lens.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Elastic polishing tool, 2 ... Polishing body base material, 3 ... Elastic polishing body, 31 ... The surface facing the to-be-polished surface 5a of the elastic polishing body 3, 4 ... Polishing pad, 5 ... Eyeglass lens as to-be-polished object, 5a ... polished surface, 6 ... bonding agent, 7 ... mounting jig, 8 ... discharge nozzle, 9 ... slurry, 50 ... semi-finished lens, 50a ... molding surface, 60 ... shape of inner peripheral edge of spectacle frame, a ... ellipse The long diameter of the shape, b: the short diameter of the elliptical shape, c: the diameter of the elastic polishing body 3, d: the outermost diameter of the substantially elliptical shape, e: the moving distance of the elastic polishing tool 1, f: the shortest diameter of the substantially elliptical shape, t: thickness of the contour of the outer periphery, r: chamfered surface, O1: rotation center of the spectacle lens 5, O2: rotation center of the elastic polishing tool 1.

Claims (5)

An elastic polishing tool having an outer diameter smaller than the outermost diameter of the lens is brought into contact with the surface to be polished of the lens having a substantially elliptical outer periphery.
In the lens polishing method of rotating and polishing the elastic polishing tool and / or the lens while rotating the lens and the elastic polishing tool,
The polished surface of the lens has a concave shape,
A method for polishing a lens, wherein a range of movement of a rotation center of the elastic polishing tool that moves relative to the lens is within the shortest diameter of the substantially elliptical shape. The lens polishing method according to claim 1, wherein an outer diameter of the elastic polishing tool is:
“Outer shape of the elastic polishing tool ≧ (outer diameter of the lens−shortest diameter of the lens)”,
A method for polishing a lens, characterized in that the value is represented by: The lens polishing method according to claim 1 or 2,
A circular range of the rotation center of the elastic polishing tool with respect to the lens, that is, a circular area drawn by abutting the rotation center of the elastic polishing tool moving relative to the lens,
The lens polishing method, wherein the lens is moved within a range from a rotation center of the lens to a shortest position of a contour of an outer peripheral portion. In the lens polishing method according to any one of claims 1 to 3,
A step of calculating a lens surface shape and a lens outer shape;
Creating a polished surface based on the calculated surface shape and outer shape; and
A step of polishing the surface to be polished whose shape has been created;
A lens polishing method comprising: The lens polishing method according to claim 4,
A method for polishing a lens, characterized in that the contour thickness of the outer peripheral portion after creation of the shape of the surface to be polished is greater than zero (0) and has an outer shape with a value within a range of 2 mm.

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