# Patent

## Title
Optical lens

## Abstract

Provided is an optical lens having a pattern formed therein to be used as a spectacle lens, wherein the pattern can be viewed from outside while the field of vision of the wearer can be ensured without discomfort. An optical lens includes a lens substrate, an antireflection film arranged to cover the side of one principal surface of the lens substrate, and a transparent pattern formed by a light transmissive material and arranged in a position where the transparent pattern is to be laminated to the antireflection film; wherein the transparent pattern is visible when viewed from the side of the one principal surface of the lens substrate. The antireflection film has a structure formed by alternately laminating a low refractive index film and a high refractive index film. The transparent pattern is arranged between the layers of the antireflection film, or above or below the antireflection film.

## Background
TECHNICAL FIELD
The present invention relates to an optical lens; more particularly, the present invention relates to an optical lens having a pattern formed therein and favorable to be used as a spectacle lens, wherein the pattern can be viewed from outside without disturbing the field of vision of the wearer of the spectacles, for example.
BACKGROUND ART
A spectacle lens has various films coated on a lens substrate thereof. Examples of the various films include a hard coat film, an antireflection film, a water-repellent film and the like, wherein the hard coat film is adapted to prevent the lens substrate from being scratched, the antireflection film is adapted to prevent light from being reflected by lens surface, and the water-repellent film is adapted to prevent water spotting on the lens. Apart from the aforesaid configuration, another configuration is proposed in which, as a film for reducing the amount of the light incident on the eye of the wearer of the spectacles, a semi-transmissive thin film is coated on the entire surface of the lens in a dot-like manner, and an antireflection film is coated on the semi-transmissive thin film (see Patent document 1, for example).
In recent years, a plastic lens light in weight and excellent in dyeing affinity is favorably used as a high-fashion spectacle lens; and further, in order to improve the designability, a configuration is proposed in which a pattern is formed on the lens by applying a pigmented coating on the lens using an inkjet method.
PRIOR ART DOCUMENTS
Patent Documents


    Patent document 1: Japanese Unexamined Patent Application Publication No. 2008-55253
    Patent document 2: WO00-67051 (particularly page 7)


DISCLOSURE OF THE INVENTION
Problems to be Solved by the Invention
However, in the case where a pattern is to be formed on the lens to improve the designability, for example, if the aforesaid configuration is used in which the pigmented coating is simply coated on the lens, the pattern of the pigmented coating will also be viewed by the wearer of the spectacles. Thus, the aforesaid configuration not only causes the wearer of the spectacles to feel disturbed, but also is a factor that impairs the field of vision of the wearer.
Thus, it is an object of the present invention to provide an optical lens having a pattern formed therein, wherein the pattern can be viewed from outside, while the field of vision of the wearer can be ensured without discomfort.
Means for Solving the Problems
To achieve the aforesaid object, an optical lens according to an aspect of the present invention is provided which includes a lens substrate, an antireflection film arranged to cover the side of one principal surface of the lens substrate, and a transparent pattern formed by a light transmissive material and arranged in a position where the transparent pattern is to be laminated to the antireflection film. The antireflection film has a configuration formed by laminating a plurality of material films having different refractive indexes. The transparent pattern may be arranged between the layers of the plurality of material films of the antireflection film, or be arranged above the antireflection film, or be arranged below the antireflection film; and is visible when viewed from the side of the one principal surface of the lens substrate.
In the optical lens having the aforesaid configuration, by laminating the transparent pattern to the antireflection film having the multi-layer structure, the light reflection characteristic of the light incident to the lens from the side of the antireflection film is different between the portion where the transparent pattern is laminated and the portion where the transparent pattern is not laminated. Thus, when viewing the lens from the side of the antireflection film, the antireflection function of the antireflection film is maintained, yet the transparent pattern can be viewed as the aforesaid difference of the light reflection characteristic. On the other hand, when viewing the lens at a very close distance from the side opposite the antireflection film, the transparent pattern is not easily viewed.
Further, it is preferred that the aforesaid transparent pattern is arranged between the lens substrate and the antireflection film. With such a configuration, it is possible to obtain a normal configuration in which the surface of the lens substrate on the side of the one principal surface is evenly covered by the antireflection film, without impairing the continuity of the layer structure of the antireflection film.
Further, in such a configuration, it is preferred that the refractive index of the transparent pattern is higher than the refractive indexes of the layers that sandwich the transparent pattern. With such a configuration, when viewing the optical lens from the side of the antireflection film, the visibility of the transparent pattern can be improved even if the transparent pattern is a thin film with a single layer structure.
Advantages of the Invention
As described above, according to the present invention, it is possible to provide an optical lens having a pattern formed therein and favorable to be used as a spectacle lens, wherein the pattern can be viewed from outside while the field of vision of the wearer can be ensured without discomfort.



BRIEF DESCRIPTION OF DRAWINGS
FIGS. 1A and 1B are respectively a plan view and a cross-sectional view showing the configuration of an optical lens according to a first embodiment;
FIGS. 2A, 2B and 2C are producing process drawings (part one) showing a producing procedure of the optical lens according to the first embodiment;
FIGS. 3A and 3B are producing process drawings (part two) showing the producing procedure of the optical lens according to the first embodiment;
FIGS. 4A, 4B and 4C are producing process drawings (part three) showing the producing procedure of the optical lens according to the first embodiment;
FIGS. 5A and 5B are respectively a plan view and a cross-sectional view showing the configuration of an optical lens according to a second embodiment;
FIGS. 6A and 6B are respectively a plan view and a cross-sectional view showing the configuration of an optical lens according to a third embodiment;
FIGS. 7A and 7B are producing process drawings (part one) showing a producing procedure of the optical lens according to the third embodiment; and
FIGS. 8A and 8B are producing process drawings (part two) showing the producing procedure of the optical lens according to the third embodiment.



MODES FOR CARRYING OUT THE INVENTION
Embodiments of the present invention will be described in the following order based on the attached drawings.
1. First embodiment (an example in which an island-like transparent pattern is formed between an antireflection film and a lens substrate)
2. Second embodiment (an example in which a transparent pattern having an aperture is formed between the antireflection film and the lens substrate)
3. Third embodiment (an example in which an island-like transparent pattern is formed above the antireflection film).
Note that, in the aforesaid embodiments, the same components are denoted by the same reference numerals, and the explanation thereof will not be repeated.
1. First Embodiment
Configuration of Optical Lens According to First Embodiment
FIGS. 1A and 1B are views for explaining the configuration of an optical lens 1a according to a first embodiment, wherein FIG. 1A is a plan view, and FIG. 1B is a cross section taken along line a-a′ of FIG. 1A. The optical lens 1a of the first embodiment shown in FIGS. 1A and 1B is favorable to be used as a spectacle lens, for example, and is configured as below.
To be specific, the optical lens 1a has a hard coat film 13, an antireflection film 15 and a water-repellent film 17 laminated, in this order, to one principal surface of a lens substrate 11 thereof. Particularly, the feature of the optical lens 1a according to the first embodiment is that an island-like transparent pattern 19a is formed between the hard coat film 13, which is formed on the lens substrate 11, and the antireflection film 15. The detail configuration of the components constituting the optical lens 1a will be described below in the order from the lens substrate 11.
[Lens Substrate 11]
The lens substrate 11 is formed into a predetermined lens shape by using a plastic material commonly used for producing optical lenses. The refractive index of the plastic material is (nD) 1.50 to 1.74, for example. Examples of such plastic material include allyl diglycol carbonate, urethane resin, polycarbonate, thiourethane resin, and episulfide resin. Here, when the optical lens 1a is used to configure a pair of spectacles, the surface of the lens substrate 11 that forms the front side of the spectacles is defined as a “one principal surface”; and the aforesaid layers (i.e., the films from the hard coat film 13 to the water-repellent film 17, and the transparent pattern 19a) are laminated to the one principal surface.
[Hard Coat Film 13]
The hard coat film 13 is used as the base of the antireflection film 15, and is formed of a material containing an organosilicon compound, for example. The refractive index of the hard coat film 13 is close to the refractive index of the aforesaid plastic material. To be specific, the hard coat film 13 has a refractive index of about (nD) 1.49 to 1.70, and film configuration is selected according to the material of the lens substrate 11.
[Antireflection Film 15]
The antireflection film 15 has a multi-layer structure formed by laminating a plurality of material films one upon another wherein the plurality of material films each have different refractive index, and is adapted to prevent light reflection by interference. Examples of the antireflection film 15 include the one which has a multi-layer structure formed by alternately laminating a low refractive index film 15a and a high refractive index film 15b one upon another. The low refractive index film 15a is formed of, for example, silica dioxide (SiO2) which has a refractive index of about 1.43 to 1.47. The high refractive index film 15b is formed of a material having a refractive index higher than the refractive index of the low refractive index film 15a, wherein such material is composed of, at a proper rate, a plurality of metal oxides such as niobium oxide (Nb2O5), tantalum oxide (Ta2O5), titanium oxide (TiO2), zirconium oxide (ZrO2), yttrium oxide (Y2O3), aluminum oxide (Al2O3) and the like.
In the antireflection film 15 formed of the low refractive index film 15a and the high refractive index film 15b, the number of the laminated layers is not particularly limited. As an example, the antireflection film 15 may be formed by laminating seven layers of refractive index films, which are a low refractive index film 15a-1, a high refractive index film 15b-2, . . . a low refractive index film 15a-7, one upon another in this order from the side of the lens substrate 11. The film thickness of each low refractive index film 15a and each high refractive index film 15b is set according to each refractive index so that a predetermined phase difference is obtained.
As an example, the antireflection film 15 may have a film configuration in which the film thickness of the low refractive index film 15a and the film thickness of the high refractive index film 15b are set according to the refractive index thereof so that, in the order from the side of the lens substrate 11, the combined phase difference of three layers of “low refractive index film 15a-1/high refractive index film 15b-2/low refractive index film 15a-3” is [λ/4], the combined phase difference of three layers of “high refractive index film 15b-4/low refractive index film 15a-5/high refractive index film 15b-6” is [λ/2], and the phase difference of one layer of “low refractive index film 15a-7” is [λ/4].
[Water-Repellent Film 17]
The water-repellent film 17 is formed of, for example, an organosilicon compound having a fluorine-substituted alkyl group. The film thickness of the water-repellent film 17 is set so that antireflection function is exhibited in combination with the antireflection film 15.
[Transparent Pattern 19a]
The transparent pattern 19a is provided as an ornamental pattern, logo, character or the like, and is configured as an island-like pattern formed of a light transmissive material. The transparent pattern 19a used in the first embodiment needs to have transparency with respect to visible light, for example; and it is particularly preferred that the refractive index of the transparent pattern 19a is higher than the refractive indexes of the layers that sandwich the transparent pattern 19a. The film thickness of the transparent pattern 19a is suitably adjusted based on both the refractive index of the material constituting the transparent pattern 19a and the required visibility of the transparent pattern 19a when viewed from the side of the water-repellent film 17. Incidentally, the transparent pattern 19a may also be formed by laminating a plurality of different material layers one upon another.
The material used to form the transparent pattern 19a has a refractive index higher than both the refractive index of the hard coat film 13 and the refractive index of the low refractive index film 15a-1, which sandwich the transparent pattern 19a in between. The material identical to the material constituting the high refractive index film 15b of the antireflection film 15 is preferably used as the material of the transparent pattern 19a. In the case where such material is used to form the transparent pattern 19a, the film thickness of the transparent pattern 19a is about 10 nm. With such a configuration, it is possible to obtain a high visibility of the transparent pattern 19a when viewing the lens from the side of the water-repellent film 17. Incidentally, if it is purposely to obtain a low visibility of the transparent pattern 19a, all things that need to be done is to adjust the refractive index and film thickness of the transparent pattern 19a. 
In the optical lens 1a having the aforesaid configuration, a hard coat film, an antireflection film and a water-repellent film may also be laminated to the optical lens 1a on the surface that forms the inner side of the spectacles configured by the optical lens 1a (i.e., on the surface facing the wearer) one on another in this order from the side of the lens substrate 11.
<Method for Producing Optical Lens of First Embodiment>
FIGS. 2A to 4C are producing process drawings showing a producing procedure of the optical lens of the first embodiment having the aforesaid configuration. The producing procedure of the optical lens of the first embodiment will be described below based on these drawings, in the case where the optical lens is applied to spectacles.
[FIG. 2A]
First, as shown in FIG. 2A, the lens substrate 11 is prepared. The lens substrate 11 is selected based on the optical prescription and shape (i.e., contour shape) according to the order (specification) of the spectacles to be configured using the optical lens, and is polished according to necessity. Examples of the lens substrate 11 include a spectacle single-vision lens.
A geometric center G.C and an optical center O.C are determined for the lens substrate 11 by measurement. Further, tentative dot marks M1 to M3, which show optical coordinates including the optical center O.C, are marked on the side of the one principal surface of the lens substrate 11. The dot marks M1 to M3 are marked using red ink, for example. As an example, the optical center O.C is regarded as the center dot mark M2, and the dot marks M1, M3 are arranged respectively on the right side and left side of the center dot mark M2 at two points apart from the center dot mark M2 by equal distance.
[FIG. 2B]
Next, as shown in FIG. 2B, the position of the center (frame center) F.C of a contour shape F of the lens substrate 11 is detected based on both the data of the three-dimensional contour shape F of the optical lens created according to the order and the optical coordinates indicated by the dot marks M1 to M3 on the lens substrate 11.
[FIG. 2C]
Thereafter, as shown in FIG. 2C, based on the relationship between the optical center O.C and the frame center F.C, the contour shape F of a lens region is determined with respected to the lens substrate 11. Further, based on the dot marks M1 to M3 which indicate the optical coordinates, reference marks m1 to m4 are formed on the lens substrate 11, wherein the reference marks m1 to m4 serve as a reference of the contour shape F. The reference marks m1 to m4 are designed so that the upper side, lower side, right side and left side of the lens can be distinguished, and further, it is preferred that the reference marks m1 to m4 are designed so that it is possible to distinguish whether the lens is a right lens or a left lens of the spectacles. For example, the reference marks m2, m4, which indicate the right and left, are marked as arrows pointing to the center of the spectacles.
Further, the reference marks m1 to m4 are marked at the points outside the lens region surrounded by the contour shape F. Thus, after shape-cutting the lens substrate 11 to match the contour shape F, the reference marks m1 to m4 marked on the lens will not be left. Incidentally, the drawing shows a case where the reference marks m1 to m4 are laid out with the optical center O.C as a reference. However, the reference marks m1 to m4 may also be laid out with the frame center F.C as a reference.
The aforesaid reference marks m1 to m4 are directly formed on the one principal surface of the lens substrate 11 by, for example, a laser marker. At this time, laser is irradiated on the lens substrate 11, wherein the power of the laser is set to a level so that the lens substrate 11 will not be damaged due to the heat influence. Incidentally, the reference marks m1 to m4 do not have to be formed by a laser marker, but may also be formed by other methods such an inkjet method. At this time, it is important to select a material as the ink for forming the marks, so that the marks will not be removed together with a masking layer when performing a masking layer removing step (which is to be described later).
The process for forming the reference marks m1 to m4 described above is based an example in which the lens substrate 11 is a single-vision lens. However, the lens substrate 11 does not have to be a single-vision lens, but may also be a multi-focal lens, a progressive-addition lens or other lens. In the case where a multi-focal lens is used, the frame center F.C is detected with the vertex of a portion called “segment” as a reference, so as to determine the contour shape F and form the reference marks m1 to m4. In the case where a progressive-addition lens is used, the frame center F.C is detected with a hidden mark (layout reference mark) as a reference, so as to determine the contour shape F and form the reference marks m1 to m4. Further, in the case where a progressive-addition lens is used, a prism reference point is regarded as the center dot mark M2, and the dot marks M1, M3 are arranged respectively on the right side and left side of the center dot mark M2 at two points apart from the center dot mark M2 by equal distance, and the reference marks m1 to m4 may be laid out based on the dot marks M1 to M3.
After the reference marks m1 to m4 are formed, the dot marks M1 to M3 are rubbed off.
[FIG. 3A, FIG. 3B]
After the reference marks m1 to m4 have been formed in the aforesaid manner, the hard coat film 13 is formed on the lens substrate 11 as shown in the plan view of FIG. 3A and the cross sectional view of FIG. 3B (equivalent to a cross section taken along line a-a′ of FIG. 3A). The hard coat film 13 is formed by, for example, a dipping method using a solution having an organosilicon compound dissolved therein.
Next, a modification treatment is performed for the surface of the hard coat film 13. As the modification treatment, a treatment for ensuring wettability of the surface of the hard coat film 13 with respect to the ink to be used for forming the masking layer in the next step is performed. Here, as a treatment method that does not cause damage to the surface of the hard coat film 13, a plasma treatment using oxygen plasma is performed, for example. Incidentally, the modification treatment for ensuring wettability does not have to be limited to the plasma treatment, but may also be other methods as long as such methods do not caused damage to the hard coat film 13; for example, the modification treatment may also be an ion irradiation treatment, a corona discharge treatment, an alkali treatment or the like.
Next, an inkjet method is used to form a masking layer 21 on the hard coat film 13, which has been subjected to the modification treatment. The masking layer 21 formed here covers the entire contour shape F of the optical lens, and has an aperture pattern 21a that corresponds to the transparent pattern to be formed on the optical lens, wherein the contour shape F is established on the side of the one principal surface of the lens substrate 11. Incidentally, it is preferred that the shape of the masking layer 21 is several millimeters larger than the contour shape F, so that error caused when shape-cutting the lens substrate 11 to match the contour shape F can be absorbed.
At this time, it is important to arrange the aperture pattern 21a at a predetermined position on the lens substrate 11 preset based on the previously-created reference marks m1 to m4 to print and form the masking layer 21, without being affected by the curve of the lens substrate 11. To achieve this purpose, the masking layer 21 is formed using an inkjet method. The inkjet method used here is not particularly limited in type and method, but may either be a continuation type or an on-demand type; and if the inkjet method is an on-demand type, it may either be a piezo method or a thermal method.
Here, the ink used to form the masking layer 21 by the inkjet method is an ultraviolet cure ink (UV cure ink), for example. The ink used here can be selectively removed with respect to the hard coat film 13 even after being cured. Examples of such ink include so-called a hard UV ink and a soft UV ink, both of which are adapted to be applied to a high-adhesion/high adhesiveness non-absorbable material and can be removed by being dissolved in ethanol, acetone or the like after being cured.
In the inkjet method using such ink, it is important to adjust printing conditions to thereby form the masking layer 21 as a continuous film without uneven coating. Examples of the printing conditions include moving speed of the lens substrate with respect to the print head, resolution in moving direction, resolution in width direction perpendicular to the moving direction, size of ink droplet, drop frequency of ink droplet, number of the ink droplets dropped to the same point-of-impact, and the like. Since these printing conditions are correlated to each other, the masking layer 21 without uneven print is formed by suitably adjusting the printing conditions.
After the masking layer 21 has been formed using the aforesaid inkjet method, ultraviolet light (UV) is irradiated on the masking layer 21 to thereby cure the ink constituting the masking layer 21.
[FIG. 4A]
Next, as shown in FIG. 4A, a transparent material film 19 is formed from above the masking layer 21. Here, an evaporation method is used to form the transparent material film 19 at a predetermined film thickness (for example, 10 nm), wherein the transparent material film 19 is formed of tantalum oxide (Ta2O5) and has a refractive index of 2.05 to 2.15, for example. When forming film, it is preferred that an ion assisted deposition is performed to thereby form the transparent material film 19 with excellent film-quality and adhesion.
[FIG. 4B]
Next, as shown in FIG. 4B, a treatment is performed to remove the masking layer 21 from above the hard coat film 13, so that the transparent material film 19 above the masking layer 21 is selectively removed along with the masking layer 21. Here, the masking layer 21 is removed by performing, for example, a wet process using a solvent (ethanol, acetone or the like) to dissolve the masking layer 21. By performing such process, only the part of the transparent material film 19 formed within the aperture pattern 21a of the masking layer 21 remains on the lens substrate 11 through the hard coat film 13, and the remaining part of the transparent material film 19 is formed as the transparent pattern 19a on the lens substrate 11. The transparent pattern 19a formed in such manner is formed at the same position and with the same shape as the aperture pattern 21a formed in the masking layer 21.
[FIG. 4C]
Next, as shown in FIG. 4C, the antireflection film 15 is formed on the hard coat film 13 on which the transparent pattern 19a has been formed, and further, the water-repellent film 17 is formed on the antireflection film 15, wherein the antireflection film 15 has a multi-layer structure formed by alternately laminating the low refractive index film 15a and the high refractive index film 15b one upon another. The antireflection film 15 is formed by performing ion assisted deposition to thereby form respective layers one upon another, with each composition and each film thickness, in the order from the low refractive index film 15a-1, which is arranged on the side of the underlying layer, to the low refractive index film 15a-7.
[FIG. 1A, FIG. 1B]
Thereafter, as shown in FIGS. 1A and 1B, the lens substrate 11, which has various layers up to the water-repellent film 17 formed thereon, is shape-cut to match the contour shape F determined with respect to the lens substrate 11. At this time, as shown in FIG. 3A, a processing jig is absorbed onto the lens substrate 11 at a predetermined position aligned based on the reference marks m1 to m4 formed outside the contour shape F of the lens substrate 11, so that the lens substrate 11 is fixed to the processing jig. In such a state, a shape-cutting machine is used to shape-cut the lens substrate 11 into the contour shape F aligned based on the reference marks m1 to m4, and then the processing jig is detached to complete the optical lens 1a. Then, after performing an appearance inspection, the optical lens 1a is shipped.
<Advantages of First Embodiment>
In the optical lens 1a having the configuration of the first embodiment, by laminating the transparent pattern 19a to the antireflection film 15 with the multi-layer structure, the light reflection characteristic of the light incident to the optical lens 1a from the side of the antireflection film 15 is different between the portion where the transparent pattern 19a is formed and the portion where the transparent pattern 19a is not formed. Thus, when viewing the optical lens 1a through the water-repellent film 17 from the side of the antireflection film 15, the antireflection function of the antireflection film 15 can be maintained, yet the transparent pattern 19a can be easily viewed as the aforesaid difference of the light reflection characteristic. On the other hand, in the case where the optical lens 1a is used to form a pair of spectacles and where the optical lens 1a is viewed at a very close distance from the side of the wearer of the spectacles (i.e., from the side opposite the antireflection film 15 and the water-repellent film 17), the transparent pattern 19a is not easily viewed.
As a result, by using the optical lens 1a, it is possible to configure a pair of spectacles excellent in design by forming the transparent pattern 19a as an ornamental pattern, logo, character or the like, for example, wherein the transparent pattern 19a can be viewed from outside, while the field of vision of the wearer can be ensured without discomfort.
According to the first embodiment, the transparent pattern 19a is arranged between the lens substrate 11 and the antireflection film 15, more particularly, between the hard coat film 13 and the low refractive index film 15a-1, which constitutes the antireflection film 15. With such a configuration, it is possible to obtain a normal lens configuration in which the surface of the lens substrate 11 on the side of the one principal surface is evenly covered by the antireflection film 15, without impairing the continuity of the layer structure of the antireflection film 15. Thus, the surface of the antireflection film 15 can be evenly covered by the low refractive index film 15a-7, which is formed of a material excellent in abrasion resistance such as silica dioxide (SiO2), so that it is possible to form a lens configuration less susceptible to damage. Further, continuity of the process when forming the antireflection film 15 with the multi-layer structure is also not impaired.
Further, in such a configuration, if the refractive index of the transparent pattern 19a is higher than both the refractive indexes of both the hard coat film 13 and the low refractive index film 15a-1, which sandwich the transparent pattern 19a, the visibility of the transparent pattern 19a when viewing the optical lens 1a from the side of the antireflection film 15 can be improved even if the transparent pattern 19a is a thin film with a single layer structure. For example, in the case where the transparent pattern 19a is formed by a single layer of tantalum oxide (Ta2O5) having a film thickness of 10 nm, one-side luminous reflectance viewed from the side of the antireflection film 15 is 1.624% in the portion where the transparent pattern 19a is formed and 0.545% in the portion where the transparent pattern 19a is not formed, so that it is confirmed that sufficient visibility of the transparent pattern 19a can be obtained.
2. Second Embodiment
Configuration of Optical Lens According to Second Embodiment
FIGS. 5A and 5B are views for explaining the configuration of an optical lens 1b according to a second embodiment, wherein FIG. 5A is a plan view, and FIG. 5B is a cross section taken along line a-a′ of FIG. 5A. The optical lens 1b of the second embodiment shown in these drawings is identical to the optical lens (1a) of the first embodiment except that a transparent pattern 19b formed as an ornamental pattern, logo, character or the like is configured as a punched pattern having an aperture h.
The transparent pattern 19b having the aperture h may have the same configuration as that of the island-like transparent pattern (19a) described in the first embodiment except for the planar shape. To be specific, the transparent pattern 19b needs to have transparency with respect to visible light, for example; and it is particularly preferred that the refractive index of the transparent pattern 19b is higher than the refractive indexes of the layers that sandwich the transparent pattern 19b. The transparent pattern 19b has a film thickness which is suitably adjusted based on both the refractive index of the material constituting the transparent pattern 19b and the required visibility of the transparent pattern 19b when viewed from the side of the water-repellent film 17, and further, the transparent pattern 19b may also be formed by laminating a plurality of different material layers one upon another.
<Method for Producing Optical Lens of Second Embodiment>
The method for producing the optical lens 1b of the second embodiment having the aforesaid configuration is identical to that of the first embodiment. However, in the process for forming the masking layer 21 described with reference to FIGS. 3A and 3B, a masking layer having a reversed pattern may be formed by using an inkjet method.
<Advantages of Second Embodiment>
The optical lens 1b of the second embodiment has the same configuration as that of the optical lens of the first embodiment, i.e., the transparent pattern 19b is laminated between the hard coat film 13 and the low refractive index film 15a-1 of the antireflection film 15. Thus, similar to the first embodiment, by using the optical lens 1b, it is possible to configure a pair of spectacles excellent in design by forming the transparent pattern 19b as an ornamental pattern, logo, character or the like, for example, wherein the transparent pattern 19b can be viewed from outside, while the field of vision of the wearer can be ensured without discomfort; and continuity of the process when forming the antireflection film 15 with the multi-layer structure is also not impaired by providing the transparent pattern 19b. Further, similar to that described in the first embodiment, if the refractive index of the transparent pattern 19b is higher than the refractive indexes of both the hard coat film 13 and the low refractive index film 15a-1 of the antireflection film 15, which sandwich the transparent pattern 19b, the visibility of the transparent pattern 19b when viewing the optical lens 1b from the side of the antireflection film 15 can be improved even if the transparent pattern 19b is a thin film with a single layer structure.
3. Third Embodiment
Configuration of Optical Lens According to Third Embodiment
FIGS. 6A and 6B are views for explaining the configuration of an optical lens 1c according to a third embodiment, wherein FIG. 6A is a plan view, and FIG. 6B is a cross section taken along line a-a′ of FIG. 6A. The optical lens 1c of the third embodiment shown in these drawings differs from the optical lenses (1a, 1b) of the other embodiments in that an island-like transparent pattern 29c (i.e., a processed pattern) formed as an ornamental pattern, logo, character or the like is laminated above the antireflection film 15, and other configurations are identical to those of the first embodiment.
Compared to the transparent patterns formed in both the first embodiment and the second embodiment, the transparent pattern 29c is arranged closer to the surface of the optical lens 1c. Thus, it is preferred that the transparent pattern 29c is formed of a material having low refractive index, such as silica dioxide (SiO2) which is excellent in abrasion resistance. Like the other embodiments, the transparent pattern 29c has a film thickness which is suitably adjusted based on both the refractive index of the material constituting the transparent pattern 29c and the required visibility of the transparent pattern 29c when viewed from the side of the water-repellent film 17; and further, like the other embodiments, the transparent pattern 29c may also be formed by laminating a plurality of different material layers one upon another. Note that, in the case where the transparent pattern 29c has a laminated structure, it is preferred that the top layer portion of the transparent pattern 29c is configured by a material having low refractive index, such as silica dioxide (SiO2) which is excellent in abrasion resistance.
<Method for Producing Optical Lens of Third Embodiment>
FIGS. 7A, 7B, 8A and 8B are producing process drawings showing a producing procedure of the optical lens of the third embodiment having the aforesaid configuration. The feature of the producing procedure of the optical lens of the third embodiment will be described below with reference to these drawings, in the case where the optical lens is applied to spectacles.
[FIG. 7A]
First, the same process as shown in FIGS. 2A to 2C of the first embodiment is previously performed to form reference marks (m1 to m4), which are not shown here in FIG. 7A, on the side of the one principal surface of the lens substrate 11. Thereafter, the hard coat film 13 is formed on the one principal surface of the lens substrate 11, then a modification treatment for ensuring wettability of the surface of the hard coat film 13 is performed, and then the antireflection film 15 with a multi-layer structure is formed.
The aforesaid film-forming processes and modification treatment are performed in the same manner as the first embodiment, and the hard coat film 13 is formed by, for example, a dipping method using a solution having an organosilicon compound dissolved therein. As the modification treatment of the surface of the hard coat film 13, a plasma treatment using oxygen plasma, for example, is performed. Further, the antireflection film 15 is formed by performing ion assisted deposition to thereby form respective layers one upon another, with each composition and each film thickness, in the order from the low refractive index film 15a-1, which is arranged on the side of the underlying layer, to the low refractive index film 15a-7. However, considering that the transparent pattern is to be laminated, the film thickness of the low refractive index film 15a-7, which is the top layer of the antireflection film 15, may also be adjusted separately.
[FIG. 7B]
Next, as shown in FIG. 7B, the masking layer 21 is formed above the low refractive index film 15a-7 of the antireflection film 15 using the same inkjet method as the first embodiment. Similar to the first embodiment, the masking layer 21 formed here covers the entire contour shape of the lens, and has an aperture pattern 21a that corresponds to the transparent pattern formed on the optical lens, wherein the contour shape is established on the side of the one principal surface of the lens substrate 11. Further, similar to the first embodiment, the ink used in the inkjet method is, for example, a UV cure ink possible to be removed by being dissolved in ethanol, acetone or the like after being cured.
Further, similar to the first embodiment, after the masking layer 21 has been formed using the inkjet method, ultraviolet light (UV) is irradiated on the masking layer 21 to thereby cure the UV cure ink constituting the masking layer 21.
[FIG. 8A]
Next, as shown in FIG. 8A, the transparent material film is formed from above the masking layer 21. Here, an evaporation method is used to form the transparent material film 29 at a predetermined film thickness (for example, 10 nm), wherein the transparent material film 29 is formed of silica dioxide (SiO2) and has a refractive index of 1.43 to 1.47, for example. When forming film, an ion assisted deposition is performed necessary according to necessity to thereby form the transparent material film 29 with excellent film-quality and adhesion.
[FIG. 8B]
Thereafter, as shown in FIG. 8B, a treatment is performed to remove the masking layer 21 from above the antireflection film 15, so that the transparent material film 29 above the masking layer 21 is selectively removed along with the masking layer 21. Here, the masking layer 21 is removed by performing, for example, a wet process using a solvent (ethanol, acetone or the like) to dissolve the ink constituting the masking layer 21, so that the transparent material film 29 above the masking layer 21 is selectively removed along with the masking layer 21. By performing such process, only the part of the transparent material film 29 formed within the aperture pattern 21a of the masking layer 21 remains on the lens substrate 11 through the hard coat film 13 and antireflection film 15, and the remaining part of the transparent material film 29 is formed as the transparent pattern 29c on the lens substrate 11. The transparent pattern 29c formed in such manner is formed at the same position and with the same shape as the aperture pattern 21a formed in the masking layer 21.
[FIG. 6A, FIG. 6B]
Thereafter, as shown in FIGS. 6A and 6B, the water-repellent film 17 is formed onto the antireflection film 15 in a state where the transparent pattern 29c is covered. Next, the lens substrate 11, which has various layers up to the water-repellent film 17 formed thereon, is shape-cut to match the contour shape F determined with respect to the lens substrate 11. At this time, similar to the process described in the first embodiment, the lens substrate 11 is shape-cut to match the contour shape F, which is aligned based on the reference marks m1 to m4 formed outside the contour shape F of the lens substrate 11.
<Advantages of Third Embodiment>
Similar to the configuration of the optical lenses of the other embodiments, in the optical lens 1c of the third embodiment, the transparent pattern 29c is laminated onto the antireflection film 15, which has a multi-layer structure. Thus, similar to the other embodiments, by using the optical lens 1c, it is possible to configure a pair of spectacles excellent in design by forming the transparent pattern 29c as an ornamental pattern, logo, character or the like, wherein the transparent pattern 29c can be viewed from outside while the field of vision of the wearer can be ensured without discomfort.
The third embodiment is described based on a configuration in which the island-like transparent pattern 29c is laminated onto the antireflection film 15; however, a transparent pattern having an aperture, like the transparent pattern of the second embodiment, may also be used as the transparent pattern to be laminated onto the antireflection film 15; in such a case, the same advantages as the third embodiment can be obtained.
Further, the aforesaid first to third embodiments are described based on a configuration in which the transparent pattern is laminated above or below the antireflection film 15; however, the transparent pattern may also be arranged between the layers of the antireflection film 15, which has the multi-layer structure. In such a case, like the other embodiments described above, the transparent pattern has a film thickness which is suitably adjusted based on both the refractive index of the material constituting the transparent pattern and the required visibility of the transparent pattern when viewed from the side of the water-repellent film 17, and further, like the other embodiments described above, the transparent pattern may also be formed by laminating a plurality of different material layers one upon another.
Further, the aforesaid first to third embodiments are described based on an example in which, in the producing process of the optical lens, the masking layer 21 is formed using an inkjet method; however, the masking layer 21 does not have to be formed using the inkjet method, but may also be formed by printing or by attaching a tape. Even in such a case, by forming the masking layer 21 at accurate position in accurate shape, a transparent pattern formed of a transparent material film or a dyed pattern can be accurately formed on a lens surface, without limiting the material.
EXPLANATION OF REFERENCE NUMERALS


    
    
        1a, 1b, 1c optical lens
        11 lens substrate
        13 hard coat film
        15 antireflection film
        15a-1, 15a-3, 15a-5, 15a-7 low refractive index film
        15b-2, 15b-4, 15b-6 high refractive index film
        19a, 19b, 29c transparent pattern

## Claims

1. An optical lens comprising:
a lens substrate;
an antireflection film which has a configuration formed by laminating a plurality of material films having different refractive indexes and which is arranged to cover a side of one principal surface of the lens substrate;
a transparent pattern formed by a light transmissive material and arranged between layers of the plurality of material films of the antireflection film, or arranged above the antireflection film, or arranged below the antireflection film; and
a hard coat film provided between the lens substrate and the antireflection film to serve as a base of the antireflection film,
wherein the transparent pattern is provided on top of the hard coat film,
wherein the transparent pattern is formed as an island-like pattern or a punched pattern covering less than the entire principal surface of the lens substrate, such that the optical lens has portions where the transparent pattern is formed and portions where the transparent pattern is not formed, and
wherein the transparent pattern is visible when viewed from the side of the one principal surface of the lens substrate.

2. The optical lens according to claim 1, wherein the refractive index of the transparent pattern is higher than the refractive indexes of the layers that sandwich the transparent pattern.