# US 10,675,823 B2 · Triplet lens method of manufacture > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,675,823 B2 - Document ID: US10675823B2 - Status: Granted - Kind: B2 - Application number: 15/700,574 - Filed: 2017-09-11 - Published: 2019-03-14 - Granted: 2020-06-09 - Earliest claimed: 2017-09-11 - Assignees: LumenFlow Corp. - Applicants: LumenFlow Corp. - Inventors: Harold W. Brunt, Jr. - Web page: https://patentgrep.com/patent/US10675823B2 ## CPC - B29D 11/00403: {Producing compound lenses} - B29D 11/00442: {Curing the lens material} - G02B 3/00: Simple or compound lenses - G02B 9/16: all the components being simple - B29K 2083/00: Use of polymers having silicon, with or without sulfur, nitrogen, oxygen, or carbon only, in the main chain, as moulding material - G02B 1/041: {Lenses} - G02B 2003/0093: {characterised by the shape} - B29D: PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE (making granules B29B9/00; making preforms B29B11/00) - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - B29K: INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR {MOULDS, } REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS ## Abstract A method of forming a compound lens includes molding multiple lens elements to form a compound lens. The multiple lens elements are molded from polymers that provide each lens element with the desired optical properties. First and second lens elements formed from a first polymer can be molded around a central, third element formed from a second polymer that differs from the first polymer by the addition of a cyclic substituent group. During curing of the lens elements, cross-links are formed between the first and second polymers to form an molded, integrally formed compound lens. ## Claims ### Claim 1 A method of forming a compound lens comprising: providing a mold having a mold cavity corresponding to a shape of a triplet lens including an inner lens element and first and second outer lens elements; co-molding the first and second outer lens elements each comprising a first polymer within the mold cavity, the first outer lens element being spaced apart from the second outer lens element along the entirety thereof; molding the inner lens element comprising a second polymer within a portion of the mold between the first and second outer lens elements, wherein the inner lens element adheres to each of the first and second outer lens elements to form an integrally molded triplet lens, and wherein the second polymer differs from the first polymer by the addition of a cyclic substituent group; and removing the integrally molded triplet lens from the mold cavity, wherein cross-linking between the first and second polymers occurs during curing of the inner lens element between the first and second outer lens elements, and wherein the inner lens element includes first and second major surfaces that are opposite each other and that are co-joined with respective first and second outer lens elements, such that an optical path extends sequentially through the first outer lens element, the inner lens element, and the second outer lens element. ### Claim 2 (depends on 1) The method of claim 1 wherein the first polymer comprises a polydimethylsiloxane. ### Claim 3 (depends on 2) The method of claim 2 wherein the second polymer comprises a polydimethylsiloxane in which at least a portion of the methyl substituent groups is replaced by a cyclic substituent group including an aromatic ring or a cycloalkane ring. ### Claim 4 (depends on 1) The method of claim 1 wherein the first and second outer lens elements comprise a positive lens and the inner lens element comprises a negative lens. ### Claim 5 (depends on 1) The method of claim 1 wherein the triplet lens is a Hasting triplet such that the first and second outer lens elements are crown lens elements and the inner lens element is a flint lens element. ### Claim 6 (depends on 1) The method of claim 1 wherein the inner lens element defines an index of refraction that is greater than the index of refraction defined by the first and second outer lens elements. ### Claim 7 (depends on 1) The method of claim 1 wherein the first and second outer lens elements define an index of refraction of about 1.4. ### Claim 8 (depends on 1) The method of claim 1 wherein the inner lens element defines an index of refraction of about 1.5. ### Claim 9 (depends on 1) The method of claim 1 wherein a curing agent is provided with at least one of the first or second polymers to promote cross-linking between the first and second polymers occurs during curing. ### Claim 10 A method of forming a compound lens comprising: providing a mold having a mold cavity corresponding to a shape of a triplet lens; forming a first outer lens element comprising a first polymer in a first portion of the mold; forming a second outer lens element comprising a second polymer in a second portion of the mold, the second outer lens element being spaced apart from the first outer lens element along the entirety thereof; forming a third inner lens element comprising a third polymer in a third portion of the mold, the third portion disposed between the first and second portions of the mold, wherein the first polymer and the second polymer adhere to the third polymer to form an integrally molded triplet lens; and removing the integrally molded triplet lens from the mold, wherein at least one of the first, second, or third polymers includes a cyclic substituent group, and wherein cross-linking between the first and third polymers and the second and third polymers occurs during curing of the third inner lens element between the first and second outer lens elements, and wherein the third inner lens element includes first and second major surfaces that are opposite each other and that are co-joined with respective first and second outer lens elements, such that an optical path extends sequentially through the first outer lens element, the third inner lens element, and the second outer lens element. ### Claim 11 (depends on 10) The method of claim 10 wherein the first polymer comprises a polydimethylsiloxane. ### Claim 12 (depends on 11) The method of claim 11 wherein the second polymer comprises a polydimethylsiloxane in which at least a portion of the methyl substituent groups is replaced by a cyclic substituent group including an aromatic ring or a cycloalkane ring. ### Claim 13 (depends on 10) The method of claim 10 wherein the triplet lens is free of tie layers between the first and second outer lens elements and the third inner lens element. ### Claim 14 (depends on 10) The method of claim 10 wherein forming the first and second outer lens elements comprises at least partially curing the first and second polymers prior to forming the third inner lens element or subsequent to forming the third inner lens element. ### Claim 15 (depends on 14) The method of claim 14 wherein forming the third inner lens element comprises at least partially curing the third polymer to promote cross-linking between the first and third polymers and the second and third polymers. ### Claim 16 (depends on 10) The method of claim 10 wherein at least one of the first, second, or third polymers comprise a curing agent. ### Claim 17 (depends on 10) The method of claim 10 wherein: the first polymer has a first index of refraction; the second polymer has a second index of refraction; and the third polymer has a third index of refraction. ### Claim 18 (depends on 17) The method of claim 17 wherein the first and second indices of refraction are one of greater than or less than the third index of refraction. ### Claim 19 (depends on 18) The method of claim 18 wherein the first and second indices of refraction are the same. ### Claim 20 (depends on 10) The method of claim 10 wherein the first and second outer lens elements comprise a positive lens and the third inner lens element comprises a negative lens.