JPH07186290A - Marking method of contact lens - Google Patents

Abstract

PURPOSE:To obtain a mark excellent in visibility without deepening the mark by stamping a character or figure in the optical molding surface of a mold used in the molding of a resin mold to transfer the same to a contact lens through the resin mold. CONSTITUTION:For example, a mark character of 'SE' is applied to the optical molding surface of a mold by melt thermal processing using a YAG laser processing machine so that processing depth becomes 3mum. Next, a resin mold for a contact lens is produced using the mold to faithfully transfer a pattern to the resin mold. The concave optical surface of the lens is molded using the resin mold and the end part and convex optical surface of the lens are cut and ground together with the resin mold and the lens. As a result, since the surface of the character forms fine unevenness, good visibility is obtained even with respect to relatively shallow depth in air or water.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a marking method used for making a mark on a contact lens at a low cost with excellent visibility and without deteriorating the strength of the lens.

[0002]

2. Description of the Related Art At present, marking on a contact lens is mainly used for distinguishing the front and back of a lens when worn, and determining the lens specification, and printing or laser marking is generally known as a method therefor.

A screen printing method is generally used for printing on a contact lens, but the printed characters and figures are sufficiently resistant to a harsh environment such as scrubbing when cleaning the lens and repeated boiling disinfection. Need to get Therefore, a method is adopted in which the ink is allowed to permeate into the lens material, or the permeated ink is chemically reacted with the lens material to fix the ink inside the lens material.

On the other hand, laser marking is widely used in the processing field at present, carbon dioxide laser and YA.
Thermal processing by G laser is generally performed.

Further, Japanese Patent Application Laid-Open No. 53-10447 discloses a method in which a convex mark is formed on a lens molding die by using a photosensitive resin and the concave mark is formed on the lens by transferring the convex mark. It is disclosed.

[0006]

However, direct marking on contact lenses by printing or laser is generally expensive in many cases. Specifically, the increase in the number of marking steps requires new man-hours and devices, the frequency of handling lenses increases, and as a result, the defective product rate increases.

Further, since the marking belongs to a rear process in the lens manufacturing process and is usually performed as a separate process after the processing process for molding the lens, the base curve value, the frequency, etc. When performing marking for the purpose of discriminating the specifications, there is a possibility that a marking mistake occurs in which the marked specifications are different from the actual specifications of the lens.

Further, in the case of performing laser marking, if the processing depth of the mark is increased in order to improve the visibility of the mark, the thickness of the lens at the mark portion becomes thin, which causes the lens strength to decrease. Occurs.

Further, in the method disclosed in JP-A-53-10447, since the object for forming the mark is a lens-molding die, JP-A-59-95118 or JP-A-59-95118. Generally, it is difficult to apply to a method of machining a molding die and a lens together after molding the lens, as disclosed in JP-A-60-73836.

[0010]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a contact lens in which at least one optical surface is molded by a resin mold, and an optical mold of a mold used for molding the resin mold. It is intended to provide a method for marking a contact lens, which comprises marking characters or figures on a molding surface and transferring the marking to a contact lens through a resin mold.

Further, the marking surface of a character or a figure to be applied to the mold is characterized by providing irregularities for scattering light, and the depth of the marking of the character or the figure to be applied to the mold is determined. It is characterized in that it is in the range of 1 μm to 15 μm.

Further, as a method of marking on the mold, any one of mechanical processing, laser processing and etching processing is used.

The present invention will be described in detail below.

In a contact lens in which at least one optical surface is molded by a resin mold, a mark character or a figure desired to be applied to the lens is formed on the optical molding surface of the molding die used for manufacturing the molding resin mold for the contact lens. To
Imprint at the desired location with the desired depth.

The depth of the marking is in the range of 1 μm to 15 μm, and the optimum depth is 1 μm to 5 μm in order to achieve both sufficient visibility and lens strength, although it depends on the lens material and lens design. Range is desirable. If the depth is less than 1 μm, the visibility of the mark is extremely poor. On the contrary, if the depth is more than 15 μm, the lens strength is lowered due to the marking.

Further, as means for marking, machining according to the shape (curved surface shape) of the die used and the type of material,
Either laser processing or etching processing can be selected, but the important thing here is to adjust the processing conditions so that the processing depth can be controlled and the lens When the mark is applied to the mark, the mark surface is processed into a surface state having fine irregularities or the contour of the mark is made clear. By making the surface state with fine irregularities, the light hitting the lens is scattered at the mark character portion, which produces the effect of improving the visibility of the mark. Further, by performing processing that makes the contour of the mark clear, light is refracted at the contour portion, and similarly, the effect of enhancing the visibility of the mark is produced. Laser processing or etching is suitable for making the mark surface a fine uneven surface, and mechanical processing is suitable for making the contour of the mark clear.

Next, a molding resin die for the contact lens is manufactured using the molding die that has been subjected to the above-mentioned processing, and the contact lens is molded using the resin die. It is possible to machine the molding die and the lens together after the lens is molded by using the resin mold instead of directly using the mold for manufacturing the lens. Further, as compared with the case where printing or laser marking is performed after lens processing, marking can be performed simultaneously with lens molding by using a molding die, so that marking can be performed at low cost and without fear of marking mistakes.

[0018]

The present invention will be described in detail with reference to the following examples.

(Example 1) The optical molding surface of the molding die shown in FIG. 3, which is used for manufacturing a molding resin die for a soft contact lens, is manufactured by using a YAG laser processing machine as shown in FIG.
And, the mark character of "SE" was subjected to the melt heat processing so that the processing depth became 3 μm according to the pattern shown in FIG. Next, a resin mold for contact lenses was manufactured using the mold shown in FIG. 3, and the above pattern was faithfully transferred onto the resin mold. Furthermore, the concave side optical surface of the lens is molded using the resin mold shown in FIG. 4, and then the lens end and the convex side optical surface are cut and polished together with the resin mold and the lens as shown in FIG. This produced a soft contact lens.

The mark characters thus obtained on the soft contact lens shown in FIG. 6 faithfully transfer the processed pattern on the mold, and the character surface thus forms fine irregularities. It was confirmed that, despite the relatively shallow processing depth of 3 μm, it has good visibility even in air or water. In addition, no reduction in lens strength due to marking was confirmed.

(Embodiment 2) An optical molding surface of a molding die used for manufacturing a molding resin die for a soft contact lens is subjected to photolithographic etching to mark "SE" as shown in FIG. 7 and FIG. Processing depth of letters is 3μm
So that the character part is concave and the character surface is pear-like,
Etching processing was performed. Next, in the same manner as in Example 1, a resin mold for contact lenses was manufactured using this mold, the mark characters were faithfully transferred onto the resin mold in a convex shape, and this resin mold was used. To manufacture soft contact lenses.

The mark characters on the soft contact lens thus obtained are faithfully transferred to the mark characters on the mold, and since the character surface is pear-like and has fine irregularities, the comparison is 3 μm. It was confirmed that it has good visibility even in air or water, even though it is a shallow depth of processing. In addition, no reduction in lens strength due to marking was confirmed.

(Embodiment 3) An optical molding surface of a molding die used for manufacturing a molding resin die for a soft contact lens is subjected to a pattern as shown in FIGS. 9 and 10 by using an ultra-precision micro processing machine. The micro-machining was performed so that the mark character of "SE" was applied to the plate so that the processing depth was 3 μm. Next, in the same manner as in Example 1, a resin mold for contact lenses is manufactured by using this mold, the above mark characters are faithfully transferred onto the resin mold, and further soft contact is performed by using this resin mold. A lens was manufactured.

The mark characters on the soft contact lens thus obtained are faithfully transferred to the characters on the mold, and as a characteristic of machining, the outline of the mark character part on the mold is shown in FIG. Because of the shape like this, the contour of the mark character transferred to the lens becomes clear, and as a result, no unevenness is formed on the character surface and the processing depth is relatively shallow of 3 μm. It was confirmed that it has good visibility even in air or water.
In addition, no reduction in lens strength due to marking was confirmed.

Although three embodiments have been described above, the present invention is not limited to these.

[0026]

As described above, according to the marking method of the present invention, the mark character or figure on the lens is made into a surface state having fine irregularities or the contour is made clear to make the mark. It is possible to obtain a mark with excellent visibility at low cost by utilizing the scattering or refraction of light without increasing the depth. Further, by performing the marking by transfer via a resin mold, post-processing of the lens is also possible.

[Brief description of drawings]

FIG. 1 is a pattern diagram of a die processing pattern by a YAG laser according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of a YAG laser processed portion in the first embodiment of the present invention.

FIG. 3 is a partial cross-sectional view of a mold including engraved characters according to the first embodiment of the present invention.

FIG. 4 is a partial cross-sectional view of a resin mold including a transfer character according to the first embodiment of the present invention.

FIG. 5 is a partial cross-sectional view of a resin mold and an upper lens of the resin mold after processing the lens end portion and the convex side optical surface in Example 1 of the present invention.

FIG. 6 is an external view of a marked soft contact lens in Example 1 of the present invention.

FIG. 7 is a mold processing pattern diagram by etching processing according to the second embodiment of the present invention.

FIG. 8 is a cross-sectional view of an etched portion according to the second embodiment of the present invention.

FIG. 9 is a mold processing pattern diagram by an ultra-precision micro processing machine in Embodiment 3 of the present invention.

FIG. 10 is a sectional view of a micromachined portion according to the third embodiment of the present invention.

Claims (4)

[Claims] 1. A contact lens in which at least one optical surface is molded by a resin mold, characters or figures are marked on the optical molding surface of a mold used for molding the resin mold, and the marking is made by the resin mold. A method for marking a contact lens, which is characterized in that it is transferred to the contact lens via the. 2. An uneven surface for scattering light is provided on a surface on which a character or a figure formed on a die is engraved.
The method for marking a contact lens according to claim 1. 3. The method for marking a contact lens according to claim 1, wherein the depth of the marking of characters or figures on the mold is in the range of 1 μm to 15 μm. 4. The method of engraving a mold, any one of mechanical processing, laser processing, and etching processing is used, as claimed in claim 1, claim 2, or claim 3.
The method for marking contact lenses according to.