# US 10,121,985 B2 · Display apparatus with optical interference layer having a larger refractive index than a white light emitting layer > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,121,985 B2 - Document ID: US10121985B2 - Status: Granted - Kind: B2 - Application number: 15/786,478 - Filed: 2017-10-17 - Published: 2018-04-26 - Granted: 2018-11-06 - Earliest claimed: 2016-10-21 - Assignees: Canon Kabushiki Kaisha - Applicants: Canon Kabushiki Kaisha - Inventors: Takayuki Ito - Web page: https://patentgrep.com/patent/US10121985B2 ## CPC - H04N 23/63: by using electronic viewfinders - H10K 50/13: comprising stacked EL layers within one EL unit - H10K 59/38: comprising colour filters or colour changing media [CCM] - H10K 59/80521: {characterised by their shape} - H10K 59/878: {comprising reflective means} - H10K 59/879: {comprising refractive means, e.g. lenses} - H04N 23/53: of electronic viewfinders, e.g. rotatable or detachable - H04N 25/134: {based on three different wavelength filter elements} - H10K 59/35: comprising red-green-blue [RGB] subpixels - H10K 59/80524: {Transparent cathodes, e.g. comprising thin metal layers} - H10K 2102/351: {Thickness} - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION - H10K: ORGANIC ELECTRIC SOLID-STATE DEVICES ## Abstract A display apparatus includes on a substrate a plurality of light emitting elements in which an organic layer including a white light emitting layer is sandwiched between a lower transparent electrode and an upper electrode, and further includes a reflection layer and an optical interference layer provided between the light emitting elements and the substrate, wherein the optical interference layer is made of a material having a lower refractive index than the refractive index of the light emitting layer and the ratio (nr/nb) of a refractive index (nr) with respect to a red wavelength region to a refractive index (nb) with respect to a blue wavelength region is less than 0.95, and the orders of interference m for blue, green, and red wavelength regions are 5, 4, and 3, respectively, when the optical distance from the light emitting layer to the reflection layer is (2m+1)λ/4±(⅛)λ. ## Claims ### Claim 1 A display apparatus comprising: a substrate; a plurality of light emitting elements formed on the substrate; a reflection layer provided between the substrate and the light emitting elements; and an optical interference layer provided between the light emitting elements and the reflection layer, wherein the plurality of light emitting elements includes a transparent lower electrode, an organic layer including a white light emitting layer, and an optically transparent upper electrode in this order from the substrate side, wherein an optical distance from the white light emitting layer to the reflection layer is equal in the plurality of light emitting elements, wherein the optical interference layer has a larger refractive index than a refractive index of the white light emitting layer and a ratio (nr/nb) of a refractive index (nr) with respect to a red wavelength region to a refractive index (nb) with respect to a blue wavelength region in the optical interference layer is less than 0.95, and wherein orders of interference m in the blue, green, and red wavelength regions are 5, 4, and 3, respectively, when the optical distance from the light emitting layer to the reflection layer is (2m+1)λ/4±(⅛)λ, wherein λ represents wavelength. ### Claim 2 (depends on 1) The display apparatus according to claim 1, wherein the ratio (nr/nb) is a ratio of a refractive index at a wavelength of less than 670 nm to a refractive index at a wavelength of 450 nm in the red wavelength region. ### Claim 3 (depends on 2) The display apparatus according to claim 2, wherein the (nr/nb) is a ratio of a refractive index at a wavelength of 650 nm to the refractive index at the wavelength of 450 nm. ### Claim 4 (depends on 1) The display apparatus according to claim 1, wherein the optical interference layer comprising a transparent material having a high refractive index. ### Claim 5 (depends on 4) The display apparatus according to claim 4, wherein the transparent material is selected from the group consisting of titanium oxide, niobium oxide, zirconium oxide, silicon nitride, zinc oxide, molybdenum oxide, indium tin oxide (ITO), indium zinc oxide (IZO), zinc sulfide, and zinc selenide. ### Claim 6 (depends on 1) The display apparatus according to claim 1, further comprising a color filter configured to transmit each of light of the red wavelength region, light of the green wavelength region, and light of the blue wavelength region. ### Claim 7 (depends on 6) The display apparatus according to claim 6, wherein the color filter further includes a region configured to transmit light of all the red, green, and blue wavelength regions. ### Claim 8 (depends on 1) The display apparatus according to claim 1, wherein the optical distance from the light emitting layer to the reflection layer is (2m+1)λ/4±( 1/16)λ. ### Claim 9 (depends on 1) The display apparatus according to claim 1, wherein total thickness of the optical interference layer and the transparent lower electrode is 400 nm or more and 600 nm or less. ### Claim 10 (depends on 1) The display apparatus according to claim 1, wherein the thickness of the organic layer is 200 nm or less. ### Claim 11 (depends on 9) The display apparatus according to claim 9, wherein the thickness of the organic layer is 200 nm or less. ### Claim 12 (depends on 1) The display apparatus according to claim 1, the white light emitting layer comprising two light emitting layers. ### Claim 13 (depends on 1) The display apparatus according to claim 1, the white light emitting layer comprising three light emitting layers. ### Claim 14 (depends on 1) The display apparatus according to claim 1, thickness of the white light emitting layer is 50 nm or less. ### Claim 15 (depends on 1) The display apparatus according to claim 1, the white light emitting layer comprising a plurality of light emitting layers, the total thickness of the light emitting layers is 50 nm or less. ### Claim 16 (depends on 1) An image capturing apparatus comprising: an optical unit including a plurality of lenses; an image capturing element configured to receive light transmitted through the optical unit; and a display apparatus configured to display an image captured by the image capturing element, wherein the display apparatus is the display apparatus according to claim 1.