# US 2013/0155480 A1 · Electrowetting display apparatus and method of manufacturing the same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0155480 A1 - Document ID: US20130155480A1 - Status: Published application - Kind: A1 - Application number: 13/559,479 - Filed: 2012-07-26 - Published: 2013-06-20 - Earliest claimed: 2011-12-19 - Assignees: Samsung Display Co., Ltd. - Inventors: Sanghyun LEE; Yungkyung PARK; Dohyoung KWON; Gichang PARK; Jongseo LEE; Andrea GIRALDO; Nicolas Bergeron - Web page: https://patentgrep.com/patent/US20130155480A1 ## CPC - G09G 3/348: {based on the deformation of a fluid drop, e.g. electrowetting} - G02B 5/201: {in the form of arrays} - G02B 26/005: {based on electrowetting} - G02B 27/0018: {with means for preventing ghost images (anti-reflection coatings G02B1/11)} - Y10T 29/49117: Conductor or circuit manufacturing - G09G: ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION (arrangements for transferring data between digital computers and displays G06F3/14; static indicating arrangements comprising an association of a number of separate sources or light control cells G09F9/00; static indicating arrangements comprising integral associations of a number of light sources H01J, H01K, H10H, H05B33/12; scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission, details thereof H04N1/00) - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract An electrowetting display apparatus includes a first substrate including a first electrode that receives a gray-scale voltage and a second electrode insulated from the first electrode and receiving a reference voltage, a second substrate, a fluid layer, and a color filter. The color filter has a first thickness in an area corresponding to the first electrode and a second thickness in an area corresponding to the second electrode, and the first thickness is larger than the second thickness. Accordingly, a cell gap of the electrowetting display apparatus is reduced, and color reproducibility of the electrowetting display apparatus is improved without sacrificing brightness. ## Claims ### Claim 1 An electrowetting display apparatus comprising: a first substrate that includes at least one pixel area, the first substrate including a first electrode disposed in the pixel area and receiving a gray-scale voltage and a second electrode insulated from the first electrode and receiving a reference voltage; a second substrate that faces the first substrate; a black fluid layer disposed between the first substrate and the second substrate in the pixel area, the black fluid layer moving due to a voltage difference between the gray-scale voltage and the reference voltage; and a color filter disposed on a surface of the second substrate that is adjacent to the black fluid layer, wherein the color filter has a first thickness in an area corresponding to the first electrode and a second thickness in an area corresponding to the second electrode, and the first thickness is larger than the second thickness. ### Claim 2 (depends on 1) The electrowetting display apparatus of claim 1, wherein the second electrode is disposed at a first side of the pixel area. ### Claim 3 (depends on 2) The electrowetting display apparatus of claim 2, wherein the thickness of the color filter increases in going from the first side of the pixel area to a second side of the pixel area that is opposite the first side. ### Claim 4 (depends on 3) The electrowetting display apparatus of claim 3, wherein a surface of the color filter that faces the first substrate is inclined at a predetermined angle with respect to the first substrate. ### Claim 5 (depends on 4) The electrowetting display apparatus of claim 4, wherein the first substrate further comprises a barrier wall positioned at an edge of the pixel area. ### Claim 6 (depends on 5) The electrowetting display apparatus of claim 5, wherein the first substrate further comprises a reflective layer disposed on the first electrode and the second electrode to reflect light incident from an outside of the first substrate. ### Claim 7 (depends on 6) The electrowetting display apparatus of claim 6, wherein the black fluid layer covers an area adjacent to the first side of the pixel area according to the gray-scale voltage and the reference voltage. ### Claim 8 (depends on 7) The electrowetting display apparatus of claim 7, wherein the black fluid layer has a height greater than a height of the barrier wall when the gray-scale voltage has a voltage level corresponding to a white gray-scale. ### Claim 9 (depends on 7) The electrowetting display apparatus of claim 7, wherein the black fluid layer has a height greater than a shortest distance between the color filter and an upper surface of the first substrate when the gray-scale voltage has a voltage level corresponding to a white gray-scale. ### Claim 10 (depends on 3) The electrowetting display apparatus of claim 3, wherein the surface of the color filter that is closest to the first substrate has a curved shape. ### Claim 11 (depends on 1) The electrowetting display apparatus of claim 1, wherein the black fluid layer comprises a non-polar material. ### Claim 12 (depends on 11) The electrowetting display apparatus of claim 11, further comprising a transparent fluid layer disposed between the first substrate and the second substrate to make contact with the black fluid layer. ### Claim 13 (depends on 12) The electrowetting display apparatus of claim 12, wherein the transparent fluid layer comprises a polar material. ### Claim 14 A method of manufacturing an electrowetting display apparatus, comprising: forming a first substrate that includes at least one pixel area, the first substrate including a first electrode disposed in the pixel area and receiving a gray-scale voltage and a second electrode insulated from the first electrode and receiving a reference voltage; providing a second substrate to face the first substrate; forming a color filter on the second substrate, the color filter having a thickness that increases in going from a first side of the pixel area to a second side of the pixel area that is opposite the first side; filling a space between the first substrate and the second substrate with a black fluid and a transparent fluid; and coupling the first substrate with the second substrate. ### Claim 15 (depends on 14) The method of claim 14, wherein the forming of the color filter comprises: coating a color filter layer on a rear surface of the second substrate; providing a half-tone mask on an upper surface of the second substrate, the half-tone mask including a plurality of slits formed therethrough; exposing a portion of the color filter layer to light through the half-tone mask; and etching the exposed portion of the color filter layer. ### Claim 16 (depends on 15) The method of claim 15, wherein the slits extend in a first direction substantially parallel to the first side of the pixel area, and the slits become gradually larger with distance from the first side of the pixel area. ### Claim 17 (depends on 16) The method of claim 16, wherein the slits are spaced apart from each other at a regular interval. ### Claim 18 (depends on 16) The method of claim 16, wherein the color filter layer comprises a negative reactive material with respect to light.