# US 12,111,444 B2 · Optical element > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,111,444 B2 - Document ID: US12111444B2 - Status: Granted - Kind: B2 - Application number: 17/287,463 - Filed: 2020-06-11 - Published: 2021-12-16 - Granted: 2024-10-08 - Earliest claimed: 2019-06-14 - Assignees: Panasonic Intellectual Property Management Co., Ltd. - Applicants: Panasonic Intellectual Property Management Co., Ltd. - Inventors: Akito Sawada; Masaki Hashimoto - Web page: https://patentgrep.com/patent/US12111444B2 ## CPC - G02B 1/14: Protective coatings, e.g. hard coatings - G02B 1/04: made of organic materials, e.g. plastics (G02B1/08 takes precedence) - G02B 1/18: Coatings for keeping optical surfaces clean, e.g. hydrophobic or photo-catalytic films (G02B1/16 takes precedence) - G02B 13/001: {Miniaturised objectives for electronic devices, e.g. portable telephones, webcams, PDAs, small digital cameras (G02B23/243 takes precedence)} - B60R 11/04: Mounting of cameras operative during drive; Arrangement of controls thereof relative to the vehicle - G02B 1/115: Multilayers - G08B 13/196: using television cameras - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - B60R: VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR - G08B: SIGNALLING SYSTEMS, e.g. PERSONAL CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS ## Abstract There is provided an optical element comprising a base material comprising a resin material and a stack covering of layers disposed on the base material. In the optical element of the present disclosure, the stack covering comprises an optical multi-layered part composed of a high refractive index layer comprising Ta2O5 and a low refractive index layer comprising SiO2, the high refractive index layer and the low refractive index layer being alternately stacked in a form of 4 or more layers. Of a plurality of high refractive index layers, a first high refractive index layer situated most closely to the base material has a fissured structure. ## Claims ### Claim 1 An optical element, comprising: a base material and a stack covering of layers disposed on the base material, the base material comprising a resin material, wherein: the stack covering comprises an optical multi-layered part composed of high refractive index layers each comprising Ta2O5 and low refractive index layers each comprising SiO2, the high refractive index layers and the low refractive index layers being alternately stacked in a form of 4 to 50 individual layers or, a first high refractive index layer of the high refractive index layers comprises a fissured structure, the first high refractive index layer being situated most closely to the base material, the fissured structure comprises a low molecular density part which is positioned between respective ones of high molecular density parts in the high refractive index layers, the low molecular density part comprises Ta2O5, and a molecular density of Ta2O5 of the low molecular density part is lower than a molecular density of Ta2O5 of each of the high molecular density parts. ### Claim 2 (depends on 1) The optical element according to claim 1, wherein the fissured structure is present in an arbitrary cross section of the optical element. ### Claim 3 (depends on 1) The optical element according to claim 1, wherein the first high refractive index layer is in direct contact with the base material. ### Claim 4 (depends on 1) The optical element according to claim 1, wherein a second high refractive index layer of the high refractive index layers comprises a further fissured structure, the second high refractive index layer being situated most closely to the first high refractive index layer. ### Claim 5 (depends on 1) The optical element according to claim 1, wherein the first high refractive index layer having the fissured structure has a plurality of separate segments due to the fissured structure. ### Claim 6 (depends on 5) The optical element according to claim 5, wherein the segments each have a diameter of 5 nm to 25 nm. ### Claim 7 (depends on 1) The optical element according to claim 1, wherein: a boundary between the first high refractive index layer having the fissured structure and one of the low refractive index layers, which is in direct contact with the first high refractive index layer, comprises an uneven contour in a cross-sectional view of the optical element, and the uneven contour has a maximum height of 2 nm to 10 nm. ### Claim 8 (depends on 1) The optical element according to claim 1, wherein the first high refractive index layer has a thickness of 10 nm to 90 nm. ### Claim 9 (depends on 1) The optical element according to claim 1, wherein a second high refractive index layer of the high refractive index layers is thicker than the first high refractive index layer, the second high refractive index layer being situated most closely to the first high refractive index layer. ### Claim 10 (depends on 1) The optical element according to claim 1, wherein the base material is made of at least one selected from the group consisting of polycarbonate, cycloolefin polymer and cycloolefin copolymer. ### Claim 11 (depends on 1) The optical element according to claim 1, wherein the optical element has an average reflectance of 1% or lower for a visible light region. ### Claim 12 (depends on 1) The optical element according to claim 1, wherein the stack covering further comprises at least one additional layer selected from the group consisting of an antifouling layer, a water-repellent layer, a hydrophilic layer, an anti-fogging layer, a hard coating layer and a primer layer. ### Claim 13 (depends on 1) The optical element according to claim 1, wherein the optical element is included in a surveillance system or a vehicle. ### Claim 14 (depends on 1) The optical element according to claim 1, wherein the optical element is included in a compacted optical unit.