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CN-122008603-A - Casting lenses with surface microstructures

CN122008603ACN 122008603 ACN122008603 ACN 122008603ACN-122008603-A

Abstract

A first mold (5) is used to produce (305, 310, 315) a mold element (350), wherein the microstructure (323) is integrally formed on the mold element (350) in the form of a relief. The lens (340) is cast (320,325,330,335) using a second mold (7) that includes mold elements (350) such that the microstructures (337) are integrally formed on the lens (340).

Inventors

  • H-W.Qiu
  • A. Jaluri

Assignees

  • 依视路国际公司

Dates

Publication Date
20260512
Application Date
20210414
Priority Date
20200414

Claims (9)

  1. 1. A mold apparatus (7, 9) for casting a thermoset lens (340), comprising: A thermoplastic upper mold element (350) having a microstructure (323) in the form of a relief provided thereon, the thermoplastic upper mold element (350) being manufactured by thermoplastic injection molding (305, 310, 315); lower die element (324) A gasket or tape (321) to keep the thermoplastic upper mold element (350) separate from the lower mold element (324) and thereby form a cavity (327) for filling the cavity with a monomer (322) to be cured by thermal curing (330) to form the thermoset lens (340).
  2. 2. The mold apparatus (7, 9) of claim 1, wherein said lower mold element (324) is also thermoplastic.
  3. 3. The mold apparatus (7, 9) of claim 2, wherein the lower mold element (324) is manufactured by thermoplastic injection molding (305, 310, 315).
  4. 4. The mold apparatus (7, 9) of claim 2, wherein said thermoplastic upper mold element (350) and said thermoplastic lower mold element (324) are made of a polymer that is one of a polycarbonate, a cycloaliphatic polycarbonate copolymer, a poly (methyl methacrylate), a thermoplastic polyurethane, a cyclic olefin copolymer, a polyacrylate, a polyamide, a polysulfone, a polyester, and a polyetheretherketone, or any combination thereof.
  5. 5. The mold apparatus (7, 9) of claim 4 wherein said thermoplastic upper mold element (350) and said lower mold element (324) are fabricated from the same said polymer.
  6. 6. The mold apparatus (7, 9) of claim 4, wherein said polymer is transparent to cure a thermally curable or UV curable monomer (322) into said thermoset lens (340).
  7. 7. The mold apparatus (9) of claim 1, further comprising a hard multi-coating (442) disposed on the microstructure (323) of the thermoplastic upper mold element (350) or both the thermoplastic upper and lower mold elements (350 and 324), such hard multi-coating (442) being transferred (420) to the lens (340) after curing (330).
  8. 8. The mold apparatus (7, 9) of claim 1, wherein the microstructures (323) are microlenses optically configured with respective focal points.
  9. 9. The mold apparatus (7, 9) of claim 8, wherein said thermoset lens (340) is a single optic lens for correcting myopia.

Description

Casting lenses with surface microstructures The application is a divisional application of patent application No. 202180028334.8, the application date of the original application is 2021, 4 months and 14 days, and the application is named as casting a lens with a surface microstructure. Background Technical Field The present disclosure relates to cast thermoset lenses having microstructures on the surface. More specifically, instead of using a typical glass or metal mold, a plastic mold having microstructures on the surface is proposed to cast the lens. Alternatively, the plastic mold may be pre-coated with a reverse hard multi-coat (HMC) laminate to produce an HMC coated thermoset lens having a surface microstructure. Background Myopia is a ubiquitous ocular condition, and according to data from the burton vision institute, australia, about 23% of the world (14 million people) suffer myopia in 2000, and 50% of the world population (48 million people) will become myopic by 2050. High myopia increases the risk of vision-threatening problems such as retinal detachment, cataracts and glaucoma. Thus, it is very important to slow the progression of myopia in children. Several studies conducted in recent years have shown that the use of microlenses on the anterior surface (convex surface) of conventional single-Shot (SV) lenses to peripherally introduce myopic defocus is very effective in slowing myopia progression. Casting a thermoset lens with surface microlenses (or other microstructures such as fresnel) requires a mold with microlenses on either the concave or convex surface. However, even with micromachining, it is technically not feasible to manufacture glass molds with precise microlenses on the surface. Moreover, nickel molds by direct micromachining or replication from a master are very expensive, especially in view of the large number of molds required for the casting operation. Thus, a cost effective solution for manufacturing casting molds with surface microlenses and/or other microstructures is extremely important for producing thermoset lenses with surface microlenses at reasonable cost to make them widely available, especially to people in need thereof, to help overcome myopia epidemics. Disclosure of Invention A method according to the present disclosure includes: manufacturing a thermoplastic mold member by thermoplastic injection molding using a first mold, wherein a microstructure is integrally formed on the thermoplastic mold member in the form of a relief, and Casting a lens by a thermoset casting technique using a second mold comprising the thermoplastic mold element such that a pattern of microstructures is integrally formed on the lens, wherein the microstructures on the thermoplastic mold element are in the form of a relief relative to the pattern of microstructures on the lens. The cast thermoset lens may typically be an ophthalmic lens. Drawings FIG. 1 is a schematic block diagram of a thermoplastic injection molding process that may be used in connection with embodiments of the present concepts. Fig. 2 is a schematic block diagram of a thermoset casting process for lenses that may be used in connection with embodiments of the present concepts. Fig. 3 is a schematic block diagram of an example lens casting process in which the present embodiment may be implemented. Fig. 4 is a schematic block diagram of an alternative coating process that may be used in connection with the present embodiment. Fig. 5 is a flow chart of an exemplary lens casting process in which the present embodiment may be implemented. Detailed Description The present disclosure is best described by certain embodiments thereof, which are described in detail herein with reference to the drawings, wherein like reference numerals refer to like features throughout. It should be understood that the term "disclosure" as used herein is intended to mean the inventive concept underlying the embodiments described below, and not just the embodiments themselves. It should also be understood that the general inventive concept is not limited to the illustrative embodiments described below, and the following description should be read in this manner. Furthermore, the term "exemplary" is used herein to mean "serving as an example, instance, or illustration. Any embodiment(s) of construction, process, design, technique, etc. designated herein as exemplary is not necessarily to be construed as preferred or advantageous over other such embodiments. The particular qualities or applicability indicated herein as exemplary examples are neither intended nor should be inferred. FIG. 1 is a schematic block diagram of a typical thermoplastic injection molding process 100. In operation 110, a mold cavity 115 is formed between a Concave (CV) mold insert 112 having concave microlenses disposed on its concave surface, typically shown at microlenses 117 and referred to herein typically as microlens(s) 117, and a smooth Convex (CX) insert 114. Each mic