Method and apparatus for manufacturing spectacle lens

Abstract

To provide a method and an apparatus for manufacturing a spectacle lens capable of automatically determining the condition of a lens surface outer edge.SOLUTION: A method for manufacturing a spectacle lens comprises: an imaging step of imaging a lens substrate L; and an outer edge condition determination step of, on the basis of an image obtained in the imaging step, extracting outer edge distance information including information about a distance R from a center of a virtual circumscribed circle Vc circumscribing a lens surface outer edge L1a to the lens surface outer edge L1a at a plurality of positions on the lens surface outer edge L1a of a lens surface L1 of the lens substrate L and determining the shape of the lens surface outer edge L1a on the basis of the outer edge distance information.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a method and an apparatus for manufacturing spectacle lenses.

Background Art

[0002] Conventionally, a method of manufacturing spectacle lenses by performing various processes on a lens substrate has been known (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the process of manufacturing such spectacle lenses, it may be necessary to check the state of the outer edge of the lens surface in order to check the state of the lens substrate. Conventionally, since the state of the outer edge of such a lens surface has been visually checked by an operator, the confirmation work requires labor, and the confirmation work has become a factor that hinders the automation of the manufacturing process. In addition, since the state determination is performed based on a personal sense in the confirmation work, there has been a problem that variations are likely to occur in the determination results.

[0005] Therefore, an object of the present invention is to provide a method and an apparatus for manufacturing spectacle lenses that can automatically determine the state of the outer edge of the lens surface with a simple configuration.

Means for Solving the Problems

[0006] One aspect of the method for manufacturing spectacle lenses according to the present invention includes an imaging step of imaging a lens substrate, and based on the image obtained in the imaging step, at a plurality of locations on the outer edge of the lens surface of the lens substrate, the distance from the center of the virtual circumscribed circle circumscribing the outer edge of the lens surface to the outer edge of the lens surface, including the outer edge distance information, is extracted, and based on the outer edge distance information, an outer edge state determination step of determining the shape of the outer edge of the lens surface is provided, thereby solving the above problems. Another aspect of the method for manufacturing spectacle lenses according to the present invention includes an imaging step of imaging a lens substrate, and based on the image obtained in the imaging step, the outer edge of the lens surface of the lens substrate is extracted, and based on the outer edge of the lens surface, an outer edge state determination step of determining whether chamfering of the outer edge of the lens substrate is necessary is provided, thereby solving the above problems. One aspect of the manufacturing apparatus for spectacle lenses according to the present invention includes an imaging device for imaging a lens substrate, and based on the image obtained by the imaging device, at a plurality of locations on the outer edge of the lens surface of the lens substrate, the distance from the center of the virtual circumscribed circle circumscribing the outer edge of the lens surface to the outer edge of the lens surface, including the outer edge distance information, is extracted, and based on the outer edge distance information, an outer edge state determination unit for determining the shape of the outer edge of the lens surface is provided, thereby solving the above problems. Another aspect of the manufacturing apparatus for spectacle lenses according to the present invention includes an imaging device for imaging a lens substrate, and based on the image captured by the imaging device, the outer edge of the lens surface of the lens substrate is extracted, and based on the outer edge of the lens surface, an outer edge state determination unit for determining whether chamfering of the outer edge of the lens substrate is necessary is provided, thereby solving the above problems.

Effects of the Invention

[0007] In the present invention, with a simple configuration, the state of the outer edge of the lens surface can be automatically determined.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Embodiments for Carrying Out the Invention

[0009] Hereinafter, a manufacturing apparatus 10 and a manufacturing method of a spectacle lens according to an embodiment of the present invention will be described with reference to the drawings. [Manufacturing Apparatus for Spectacle Lenses]

[0010] First, the manufacturing apparatus 10 of the spectacle lens of the present embodiment will be described below.

[0011] Next, the manufacturing apparatus 10 manufactures a spectacle lens by performing various processes on a transparent lens substrate L. As shown in FIG. 1, a back surface side cutting device 20 that cuts the back surface L2 side of the lens substrate L opposite to the lens surface L1 of the lens substrate L, an imaging device 30 that images the lens substrate L, and an outer edge state determination unit 40 that determines the shape of the lens surface outer edge L1a of the lens surface L1 of the lens substrate L based on the image obtained by the imaging device 30, an outer edge chamfering device 50 that chamfers the outer edge of the lens substrate L, and a polishing device 60 that polishes the lens back surface L2.

[0012] Hereinafter, each component of the manufacturing apparatus 10 will be specifically described.

[0013] First, as shown in FIG. 2, the back surface side cutting device 20 cuts the back surface L2 side of the lens substrate L formed as a semi-finished lens to a shape that satisfies the prescription of the wearer of the spectacle lens. Note that the reference symbol Lr shown in FIG. 2 indicates the portion on the back surface L2 side of the lens substrate L removed by the back surface side cutting device 20.

[0014] The imaging device 30 is installed on the downstream side of the back surface side cutting device 20, includes an imaging unit such as a CCD camera, and images the lens substrate L from a position separated in the lens thickness direction as shown in FIG. 2. In this embodiment, as shown in FIG. 2, the lens substrate L is imaged from the back surface L2 side of the lens. Conversely, the lens substrate L may be imaged from the lens surface L1 side.

[0015] The outer edge state determination unit 40 is a unit that determines the shape of the lens surface outer edge L1a of the lens surface L1 of the lens substrate L based on the image obtained by the imaging device 30. In this embodiment, the lens surface outer edge L1a of the lens surface L1 of the lens substrate L is extracted based on the image obtained by the imaging device 30, and it is a unit that determines the necessity of chamfering the outer edge of the lens substrate L based on the lens surface outer edge L1a. The outer edge state determination unit 40 includes a storage unit composed of a ROM, a RAM, etc., an input unit, an output unit, a control unit composed of a CPU, etc., a communication unit, an auxiliary storage device, etc., and is configured from a control terminal such as a personal computer that operates according to software developed in the storage unit by the control unit.

[0016] When the outer edge shape determination unit 40 determines that the shape of the lens surface outer edge L1a is not circular, the outer edge chamfering device 50 chamfers the outer edge (rim) of the lens substrate L by cutting or grinding so as to remove the acute-angled corner portion Le formed at the outer edge of the lens substrate L as shown in FIG. 2(b).

[0017] The polishing device 60 is installed on the downstream side of the outer edge chamfering device 50 and polishes the back surface L2 of the lens substrate L. [Method for manufacturing spectacle lenses]

[0018] Next, the method for manufacturing spectacle lenses using the manufacturing apparatus 10 of this embodiment will be described below.

[0019] The method for manufacturing spectacle lenses includes, in order from the upstream side, a back surface side cutting step of cutting the back surface L2 side of the lens substrate L, an imaging step of imaging the lens substrate L, an outer edge state determination step of determining the shape of the lens surface outer edge L1a of the lens surface L1 of the lens substrate L based on the image obtained in the imaging step, an outer edge chamfering step of chamfering the outer edge of the lens substrate L, and a polishing step of polishing the back surface L2.

[0020] The following specifically describes each step of the manufacturing method.

[0021] First, in the back surface cutting step, the back surface side cutting device 20 cuts the lens back surface L2 side of the lens substrate L into a shape that satisfies the prescription of the wearer of the spectacle lens. As shown in FIG. 2, the back surface cutting step is performed with the colored tape T attached to the lens surface L1 of the lens substrate L. In the present embodiment, the colored tape T is attached over the entire surface of the lens surface L1 for the purpose of protecting the convex toric lens surface L1. In the present embodiment, it is a semi-transparent blue tape.

[0022] The imaging step is performed after the back surface cutting step. As shown in FIG. 2, the imaging device 30 images the lens substrate L from a position separated in the lens thickness direction. As shown in FIG. 2, the imaging step is performed with the above-described colored tape T attached to the lens surface L1 of the lens substrate L.

[0023] In the outer edge state determination step, the outer edge state determination unit 40 determines the shape of the lens surface outer edge L1a based on the image obtained by the imaging device 30. In the present embodiment, based on the image obtained by the imaging device 30, the lens surface outer edge L1a of the lens surface L1 of the lens substrate L is extracted, and based on the lens surface outer edge L1a, it is determined whether chamfering of the outer edge of the lens substrate L is necessary.

[0024] Specifically, first, in the back surface cutting step, the lens substrate L is cut from the lens back surface L2 side. Depending on the prescription of the wearer of the spectacle lens, the lens substrate L may be cut significantly, and as shown in FIG. 2(b), it may be cut down to the lens surface L1. In this case, before cutting, the lens surface outer edge L1a of the lens surface L1, which was circular, becomes non-circular as shown in FIG. 3(b). At this time, the colored tape T is also cut together with the lens surface L1, and the shape of the colored tape T becomes non-circular in the same manner as the lens surface L1. Note that FIGS. 2(a) and 3(a) show an example of the case where the lens surface L1 is not cut in the back surface cutting process, and FIGS. 2(b) and 3(b) show an example of the case where the lens surface L1 is cut up to in the back surface cutting process.

[0025] When the lens substrate L is cut up to the lens surface L1 side, as shown in FIG. 2(b), an acute-angled corner (so-called knife edge) Le is formed at a part of the outer edge of the lens substrate L. When such an acute-angled corner Le is formed, in the polishing process which is a downstream process of the back surface cutting process, the acute-angled corner Le may damage the polishing pad. Therefore, it is desirable to chamfer the outer edge of the lens substrate L to remove the acute-angled corner Le before the polishing process or the like.

[0026] Therefore, the outer edge state determination process of the present embodiment solves the above-described problem, extracts the lens surface outer edge L1a of the lens surface L1 of the lens substrate L based on the image obtained in the imaging process, and automatically determines the necessity of chamfering the outer edge of the lens substrate L based on the lens surface outer edge L1a.

[0027] Next, the determination method in the outer edge state determination process will be specifically described. First, in the outer edge state determination process of the present embodiment, in the image obtained in the imaging process shown in FIG. 3, the color (blue) of the colored tape T attached to the lens surface L1 is extracted and subjected to binarization processing (in the present embodiment, after converting the image obtained in the imaging process into an RGB image and then converting it into an HSV color coordinate system, limiting the hue to the blue hue of the colored tape T used in the present embodiment, and performing binarization processing), the lens surface outer edge L1a is extracted assuming that the contour of the colored tape T is the lens surface outer edge L1a. Next, based on the lens surface outer edge L1a extracted above, as shown in FIG. 3, a virtual circumscribed circle Vc circumscribing the lens surface outer edge L1a is set, and outer edge distance information including the distance R from the center of the virtual circumscribed circle Vc to the lens surface outer edge L1a at a plurality of positions on the lens surface outer edge L1a, in the present embodiment, at angular positions with a predetermined angular pitch (for example, 1° pitch) in the circumferential direction of the lens surface outer edge L1a is extracted. Next, calculate the standard deviation of the distance R at multiple locations on the outer edge L1a of the lens surface. When the calculated standard deviation is less than or equal to a preset threshold value, it is determined that the shape of the outer edge L1a of the lens surface is circular and chamfering of the outer edge L1a of the lens surface is not necessary. When the standard deviation is greater than the threshold value, it is determined that the shape of the outer edge L1a of the lens surface is non-circular and chamfering of the outer edge L1a of the lens surface is necessary.

[0028] In the outer edge chamfering step, when it is determined in the outer edge state determination step that the shape of the outer edge L1a of the lens surface is non-circular and chamfering of the outer edge L1a of the lens surface is necessary, the outer edge of the lens substrate L is chamfered by the outer edge chamfering device 50 so as to remove the above-described acute-angled corner Le.

[0029] The polishing step is a step of polishing the lens back surface L2 of the lens substrate L by a polishing device 60 after the back surface side cutting step.

[0030] The manufacturing apparatus 10 and manufacturing method of the spectacle lens according to the present embodiment thus obtained include an imaging step of imaging the lens substrate L, and based on the image obtained in the imaging step, the distance R from the center of the virtual circumscribed circle Vc circumscribing the outer edge L1a of the lens surface to the outer edge L1a of the lens surface at multiple locations on the outer edge L1a of the lens surface of the lens substrate L. It has an outer edge state determination step of extracting the outer edge distance information including the above and determining the shape of the outer edge L1a of the lens surface based on the outer edge distance information. As a result, it is possible to automatically and favorably determine the shape of the outer edge L1a of the lens surface (in the case of the present embodiment, determine whether the shape of the outer edge L1a of the lens surface is circular), so that it is possible to eliminate the need for an operator to visually determine the shape of the outer edge L1a of the lens surface, and it is possible to reduce labor and suppress variations in the determination results.

[0031] In the imaging process, the lens substrate L with the colored tape T attached to the lens surface L1 is imaged. In the outer edge state determination process, by extracting the outer edge distance information on the assumption that the contour of the colored tape T is the outer edge L1a of the lens surface, even when the transparency of the lens substrate L is high (low coloration), the outer edge distance information can be extracted well and the shape of the outer edge L1a of the lens surface can be accurately determined.

[0032] In the outer edge state determination process, the standard deviation of the distance R at a plurality of locations on the outer edge L1a of the lens surface is calculated. When the calculated standard deviation is equal to or less than a preset threshold value, it is determined that the shape of the outer edge L1a of the lens surface is circular. Thus, it is possible to accurately determine whether the shape of the outer edge L1a of the lens surface is circular based on the outer edge distance information.

[0033] As described above, the embodiments of the present invention have been described in detail. However, the present invention is not limited to the above embodiments, and various design changes can be made without departing from the present invention described in the claims, such as arbitrarily combining the respective configurations of the above or below embodiments and modification examples to constitute the manufacturing apparatus 10 and manufacturing method of the spectacle lens.

[0034] For example, in the above-described embodiment, the lens substrate L is a semifinished lens, that is, the shape of the lens surface side of the convex toric surface shape (the toric surface shape with a convex shape near the center) facing the outside in the worn state is in a completed state, and the shape of the concave toric surface shape (the toric surface shape with a concave shape near the center) of the lens back surface L2 facing the eyeball side in the worn state is processed in the above-described back surface side cutting process to realize a shape that satisfies the prescription of the wearer of the spectacle lens. Although it has been described as a semifinished lens, the specific form of the lens substrate L is not limited to the above.

[0035] In the above-described embodiment, the lens substrate L with the colored tape T attached to the lens surface L1 is imaged, and in the outer edge state determination step, the outer edge distance information is extracted on the assumption that the contour of the colored tape T is the outer edge L1a of the lens surface. However, the method for extracting the outer edge distance information is not limited to this. The lens substrate L with no colored tape T attached to the lens surface L1 may be imaged, and the outer edge L1a of the lens surface L1 may be extracted from the captured image to extract the outer edge distance information.

[0036] Also, the refractive index of the lens substrate L may be any value, but the present invention is preferably applicable to a lens substrate L having a refractive index of 1.5 or more.

Explanation of Reference Numerals

[0037] 10 ··· Manufacturing apparatus 20 ··· Back surface cutting device 30 ··· Imaging device 40 ··· Outer edge state determination unit 50 ··· Outer edge chamfering device 60 ··· Polishing device L ··· Lens substrate L1 ··· Lens surface L1a ··· Outer edge of lens surface L2 ··· Lens back surface T ··· Colored tape Lr ··· Portion removed in the back surface cutting step Le ··· Acute-angled corner Vc ··· Virtual circumscribed circle

Claims

1. A method for manufacturing eyeglass lenses, The imaging process involves imaging the lens substrate, An outer edge state determination step is performed to extract outer edge distance information, which includes the distance from the center of a virtual circumscribing circle that circumscribing the outer edge of the lens surface to the outer edge of the lens surface at multiple locations on the outer edge of the lens surface of the lens substrate, based on the image obtained in the imaging step, and to determine the shape of the outer edge of the lens surface based on the outer edge distance information. A method for manufacturing eyeglass lenses, characterized by comprising the following features.

2. The method for manufacturing an eyeglass lens according to claim 1, characterized in that the outer edge state determination step determines whether the shape of the outer edge of the lens surface is circular based on the outer edge distance information.

3. The method for manufacturing an eyeglass lens according to claim 2, further comprising an outer edge chamfering step of chamfering the outer edge of the lens substrate if it is determined in the outer edge state determination step that the shape of the outer edge of the lens surface is not circular.

4. The method for manufacturing eyeglass lenses according to claim 3, further comprising a polishing step of polishing the back surface of the lens substrate as a step performed after the outer edge chamfering step.

5. In the imaging step, the lens substrate with the colored tape attached to the lens surface is imaged. The method for manufacturing eyeglass lenses according to claim 1, characterized in that, in the outer edge state determination step, the outline of the colored tape is assumed to be the outer edge of the lens surface and the outer edge distance information is extracted.

6. The method for manufacturing eyeglass lenses according to claim 5, further comprising a back-side cutting step, which is performed prior to the imaging step, in which the back surface of the lens opposite to the lens surface is cut while a colored tape is attached to the lens surface.

7. The method for manufacturing an eyeglass lens according to claim 1, characterized in that the outer edge state determination step involves calculating the standard deviation of the distance at multiple locations on the outer edge of the lens surface, and determining that the shape of the outer edge of the lens surface is circular if the calculated standard deviation is less than or equal to a preset threshold.

8. A method for manufacturing eyeglass lenses, The imaging process involves imaging the lens substrate, An outer edge state determination step is performed to extract the outer edge of the lens surface of the lens substrate based on the image obtained in the imaging step, and to determine whether or not chamfering is necessary on the outer edge of the lens substrate based on the outer edge of the lens surface, A method for manufacturing eyeglass lenses, characterized by comprising the following features.

9. A device for manufacturing eyeglass lenses, An imaging device for imaging a lens substrate, An outer edge state determination unit that, based on the image obtained by the imaging device, extracts outer edge distance information, including the distance from the center of a virtual circumscribing circle that circumscribing the outer edge of the lens surface to the outer edge of the lens surface at multiple locations on the outer edge of the lens surface of the lens substrate, and determines the shape of the outer edge of the lens surface based on the outer edge distance information, An apparatus for manufacturing eyeglass lenses, characterized by comprising the following features.

10. A device for manufacturing eyeglass lenses, An imaging device for imaging a lens substrate, An outer edge state determination unit extracts the outer edge of the lens surface of the lens substrate based on the image captured by the imaging device, and determines whether or not chamfering is necessary on the outer edge of the lens substrate based on the outer edge of the lens surface; An apparatus for manufacturing eyeglass lenses, characterized by comprising the following features.

Images