# US 9,753,299 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 9,753,299 B2 - Document ID: US9753299B2 - Status: Granted - Kind: B2 - Application number: 14/524,893 - Filed: 2014-10-27 - Published: 2015-07-09 - Granted: 2017-09-05 - Earliest claimed: 2012-04-26 - Assignees: Asahi Glass Company, Limited - Applicants: Asahi Glass Company, Limited - Inventors: So Ishido; Hiroki Hotaka; Kensuke Ono; Takuji Nomura - Web page: https://patentgrep.com/patent/US9753299B2 ## CPC - G02B 27/58: Optics for apodization or superresolution; Optical synthetic aperture systems - G02B 1/11: Anti-reflection coatings - G02B 5/005: {Diaphragms (for cameras G03B9/02)} - G02B 5/205: {Neutral density filters} - G02B 5/206: {comprising particles embedded in a solid matrix} - G02B 5/208: {for use with infrared or ultraviolet radiation, e.g. for separating visible light from infrared and/or ultraviolet radiation} - G02B 5/223: {containing organic substances, e.g. dyes, inks or pigments} - G02B 5/281: {designed for the infrared light} - G02B 27/0927: {Systems for changing the beam intensity distribution, e.g. Gaussian to top-hat} - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS ## Abstract An optical element in which transmittance of light monotonically decreases from a center portion toward a peripheral portion, the optical element includes an absorbing material portion made of a material that absorbs a part of light and formed such that its thickness monotonically increases from the center portion toward the peripheral portion; and a transparent material portion made of a material that transmits light and is stacked on the absorbing material portion, a total thickness of the absorbing material portion and the transparent material portion being substantially constant. ## Claims ### Claim 1 An optical element comprising: an absorbing material portion made of a material that absorbs a part of light and formed such that the absorbing material portion has a thickness monotonically increases from a center portion of the absorbing material portion toward a peripheral portion of the absorbing material portion; and a transparent material portion made of a material that transmits light and stacked on the absorbing material portion, wherein the absorbing material portion and the transparent material portion are formed such that a total thickness of the absorbing material portion and the transparent material portion is substantially constant, and the absorbing material portion is formed such that the absorbing material portion satisfies |T450−T650|≦5% within a region where an average value of transmittance from wavelength of 380 nm to 700 nm is between 40% to 80%, where T450 is transmittance at a wavelength of 450 nm and T650 is transmittance at a wavelength of 650 nm. ### Claim 2 (depends on 1) The optical element according to claim 1, wherein transmittance of the absorbing material portion conforms to a Gaussian distribution from the center portion toward the peripheral portion. ### Claim 3 (depends on 1) The optical element according to claim 1, wherein the absorbing material portion and the transparent material portion are formed such that a refractive index of the absorbing material portion and a refractive index of the transparent material portion are substantially equal. ### Claim 4 (depends on 1) The optical element according to claim 1, wherein the absorbing material portion has a thickness at the center portion which is less than or equal to 0.5 μm. ### Claim 5 (depends on 1) The optical element according to claim 1, wherein the absorbing material portion and the transparent material portion are formed such that a temperature coefficient of a refractive index of the absorbing material portion and a temperature coefficient of a refractive index of the transparent material portion are substantially equal. ### Claim 6 (depends on 1) The optical element according to claim 1, wherein the absorbing material portion is formed such that an OD value of the absorbing material portion, when a thickness of the absorbing material portion is 10 μm, is greater than or equal to 0.2. ### Claim 7 (depends on 1) The optical element according to claim 1, wherein the absorbing material portion is formed such that a haze value of the absorbing material portion, when an OD value of the absorbing material portion is 1, is less than or equal to 10%. ### Claim 8 (depends on 1) The optical element according to claim 1, wherein the absorbing material portion is formed such that a refractive index of the absorbing material portion for light whose wavelength is 589 nm is greater than or equal to 1.35 and less than or equal to 1.65. ### Claim 9 (depends on 1) The optical element according to claim 1, wherein the absorbing material portion and the transparent material portion are formed such that a difference between a maximum value and a minimum value of the total thickness of the absorbing material portion and the transparent material portion within an effective region of the optical element is less than or equal to 1 μm. ### Claim 10 (depends on 1) The optical element according to claim 1, wherein the material of the absorbing material portion includes at least one of titan black and carbon black. ### Claim 11 (depends on 1) The optical element according to claim 1, further comprising: a base material on which the absorbing material portion and the transparent material portion are stacked, wherein the base material is a resin film or a glass. ### Claim 12 (depends on 1) The optical element according to claim 1, further comprising: a cover glass on which the absorbing material portion and the transparent material portion are stacked. ### Claim 13 (depends on 1) The optical element according to claim 1, wherein the light is visible light. ### Claim 14 (depends on 1) The optical element according to claim 1, further comprising: an antireflection film formed on one surface or both surfaces of a stacked structure of the absorbing material portion and the transparent material portion, wherein the antireflection film reduces reflection of light having a wavelength in a range between 430 nm to 630 nm. ### Claim 15 (depends on 1) The optical element according to claim 1, wherein the absorbing material portion and the transparent material portion are formed such that a difference between a maximum value and a minimum value of an optical path length at wavelength of 650 nm within an effective region of the optical element is less than or equal to the wavelength. ### Claim 16 (depends on 1) The optical element according to claim 1, wherein the material of the absorbing material portion comprises a photocurable absorbing material having a viscosity which is greater than or equal to 50 mPa·s and less than or equal to 3500 mPa·s at 30° C. ### Claim 17 (depends on 1) The optical element according to claim 1, further comprising: an infrared cut filter on which the absorbing material portion and the transparent material portion are stacked. ### Claim 18 (depends on 17) The optical element according to claim 17, wherein the infrared cut filter includes a phosphate glass or a fluorophosphate glass. ### Claim 19 (depends on 17) The optical element according to claim 17, wherein the infrared cut filter includes a dye. ### Claim 20 (depends on 17) The optical element according to claim 17, wherein the infrared cut filter includes a dielectric multilayer film. ### Claim 21 (depends on 1) The optical element according to claim 1, further comprising: a lens, wherein the absorbing material portion is stacked on the lens. ### Claim 22 An optical element, comprising: an absorbing material portion made of a material that absorbs a part of light and formed such that the absorbing material portion has a thickness monotonically increases from a center portion of the absorbing material portion toward a peripheral portion of the absorbing material portion; and a transparent material portion made of a material that transmits light and stacked on the absorbing material portion, wherein the absorbing material portion and the transparent material portion are formed such that a total thickness of the absorbing material portion and the transparent material portion is substantially constant, and the absorbing material portion is formed such that an OD value of the absorbing material portion, when a thickness of the absorbing material portion is 10 μm, is greater than or equal to 0.2. ### Claim 23 An optical element, comprising: an absorbing material portion made of a material that absorbs a part of light and formed such that the absorbing material portion has a thickness monotonically increases from a center portion of the absorbing material portion toward a peripheral portion of the absorbing material portion; and a transparent material portion made of a material that transmits light and stacked on the absorbing material portion, wherein the absorbing material portion and the transparent material portion are formed such that a total thickness of the absorbing material portion and the transparent material portion is substantially constant, and the absorbing material portion is formed such that a haze value of the absorbing material portion, when an OD value of the absorbing material portion is 1, is less than or equal to 10%. ### Claim 24 An optical element, comprising: an absorbing material portion made of a material that absorbs a part of light and formed such that the absorbing material portion has a thickness monotonically increases from a center portion of the absorbing material portion toward a peripheral portion of the absorbing material portion; and a transparent material portion made of a material that transmits light and stacked on the absorbing material portion, wherein the absorbing material portion and the transparent material portion are formed such that a total thickness of the absorbing material portion and the transparent material portion is substantially constant, and the material of the absorbing material portion comprises a photocurable absorbing material having a viscosity which is greater than or equal to 50 mPa·s and less than or equal to 3500 mPa·s at 30° C.