# US 2021/0278747 A1 · Variable diaphragm and control method thereof > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0278747 A1 - Document ID: US20210278747A1 - Status: Published application - Kind: A1 - Application number: 17/255,516 - Filed: 2020-04-17 - Published: 2021-09-09 - Earliest claimed: 2019-04-19 - Assignees: Boe Technology Group Co., Ltd. - Applicants: Boe Technology Group Co., Ltd. - Inventors: Xianqin MENG - Web page: https://patentgrep.com/patent/US20210278747A1 ## CPC - G03B 9/02: Diaphragms - G01L 9/0016: {of a diaphragm} - G02B 5/005: {Diaphragms (for cameras G03B9/02)} - G02B 26/005: {based on electrowetting} - H04N 23/75: by influencing optical camera components - G02B 2207/115: Electrowetting - G03B: APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR (optical parts of such apparatus G02B; photosensitive materials or processes for photographic purposes G03C; apparatus for processing exposed photographic materials G03D) - G01L: MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE (weighing G01G) - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract A variable diaphragm and a control method thereof are provided. The variable diaphragm includes: a first substrate and a second substrate opposite to each other; a light detector on a side of the first substrate distal to the second substrate, and configured to detect an intensity of incident light and generate a first signal; an electrowetting microfluid medium layer between the first substrate and the second substrate, and including a transparent fluid medium and an opaque fluid medium immiscible with the transparent fluid medium, wherein an aperture of the variable diaphragm is formed by the transparent fluid medium, and one of the transparent fluid medium and the opaque fluid medium is a conductive medium; and a driving electrode between the first substrate and the second substrate, and configured to receive a driving voltage corresponding to the first signal and for driving the electrowetting microfluid medium layer, so as to change an area in a direction parallel to the first substrate or the second substrate of a portion of one substrate covered by the opaque fluid medium, the one substrate being one of the first substrate and the second substrate that has a larger contact area with the opaque fluid medium, thereby changing a diameter of the aperture. ## Claims ### Claim 1 A variable diaphragm, comprising: a first substrate and a second substrate opposite to each other; a light detector on a side of the first substrate distal to the second substrate, and configured to detect an intensity of incident light and generate a first signal; an electrowetting microfluid medium layer between the first substrate and the second substrate, and comprising a transparent fluid medium and an opaque fluid medium immiscible with the transparent fluid medium, wherein an aperture of the variable diaphragm is formed by the transparent fluid medium, and one of the transparent fluid medium and the opaque fluid medium is a conductive medium; and a driving electrode between the first substrate and the second substrate, and configured to receive a driving voltage corresponding to the first signal and for driving the electrowetting microfluid medium layer, so as to change an area in a direction parallel to the first substrate or the second substrate of a portion of one substrate covered by the opaque fluid medium, the one substrate being one of the first substrate and the second substrate that has a larger contact area with the opaque fluid medium, thereby changing a diameter of the aperture. ### Claim 2 (depends on 1) The variable diaphragm of claim 1, wherein the driving electrode comprises a first electrode layer and a second electrode layer opposite to each other, the first electrode layer is on a side of the first substrate proximal to the electrowetting microfluid medium layer, the second electrode layer is on a side of the second substrate proximal to the electrowetting microfluid medium layer, and the electrowetting microfluid medium layer is between the first electrode layer and the second electrode layer. ### Claim 3 (depends on 2) The variable diaphragm of claim 2, wherein the first electrode layer comprises a first block electrode covering a first surface of the electrowetting microfluid medium layer, the second electrode layer comprises a second block electrode covering a second surface of the electrowetting microfluid medium layer, and the first block electrode and the second block electrode are right opposite to each other. ### Claim 4 (depends on 2) The variable diaphragm of claim 2, wherein the first electrode layer comprises a plurality of first electrode lines extending along a first direction, the second electrode layer comprises a plurality of second electrode lines extending along a second direction, and the first direction is perpendicular to the second direction. ### Claim 5 (depends on 2) The variable diaphragm of claim 2, wherein the first electrode layer comprises a plurality of first annular electrodes concentrically arranged, the second electrode layer comprises a plurality of second annular electrodes concentrically arranged, and the plurality of first annular electrodes are in one-to-one correspondence with the plurality of second annular electrodes. ### Claim 6 (depends on 3) The variable diaphragm claim 3, further comprising a retaining wall between the first electrode layer and the second electrode layer and surrounding the electrowetting microfluid medium layer. ### Claim 7 (depends on 6) The variable diaphragm of claim 6, wherein a material of the retaining wall comprises a material of a black matrix. ### Claim 8 (depends on 1) The variable diaphragm of claim 1, further comprising a resin coating layer coated on a surface of the light detector. ### Claim 9 (depends on 8) The variable diaphragm of claim 8, wherein the light detector comprises a photoresistor. ### Claim 10 (depends on 1) The variable diaphragm of claim 1, wherein the transparent fluid medium is an insulating medium, and the opaque fluid medium is a conductive medium. ### Claim 11 (depends on 10) The variable diaphragm of claim 10, wherein the transparent fluid medium comprises one or more of deionized water, purified water and distilled water, and the opaque fluid medium comprises a conductive opaque component dissolved in a non-conductive organic solvent. ### Claim 12 (depends on 11) The variable diaphragm of claim 11, wherein the opaque component comprises one or more of natural melanin, synthetic melanin, and oxidized melanin. ### Claim 13 (depends on 1) The variable diaphragm of claim 1, wherein the first substrate and the second substrate are transparent. ### Claim 14 (depends on 1) The variable diaphragm of claim 1, wherein the driving electrode is transparent. ### Claim 15 (depends on 14) The variable diaphragm of claim 14, wherein the driving electrode comprises indium tin oxide or metal. ### Claim 16 (depends on 1) A method for controlling a variable diaphragm, the variable diaphragm being the variable diaphragm of claim 1, the method comprising: obtaining the intensity of the incident light and generating the first signal by the light detector; generating the driving voltage based on the first signal; and applying the driving voltage to the driving electrode, wherein under driving by the driving voltage, the area in the direction parallel to the first substrate or the second substrate of the portion of the one substrate covered by the opaque fluid medium is changed to change the diameter of the aperture, the one substrate being one of the first substrate and the second substrate that has a larger contact area with the opaque fluid medium. ### Claim 17 (depends on 16) The method of claim 16, wherein the area in the direction parallel to the first substrate or the second substrate of the portion of the one substrate, which is one of the first substrate and the second substrate that has a larger contact area with the opaque fluid medium, covered by the opaque fluid medium is changed, by changing a wetting angle of the transparent fluid medium or a wetting angle of the opaque fluid medium on the first substrate or the second substrate. ### Claim 18 (depends on 17) The method of claim 17, wherein the opaque fluid medium is a conductive medium, and the method comprises: adjusting the driving voltage based on the intensity of the incident light when the intensity of the incident light is reduced, to increase the wetting angle of the opaque fluid medium on the one of the first substrate and the second substrate that has a larger contact area with the opaque fluid medium, and to increase the diameter of the aperture; or adjusting the driving voltage based on the intensity of the incident light when the intensity of the incident light is increased, to reduce the wetting angle of the opaque fluid medium on the one of the first substrate and the second substrate that has a larger contact area with the opaque fluid medium, and to reduce the diameter of the aperture. ### Claim 19 (depends on 4) The variable diaphragm of claim 4, further comprising a retaining wall between the first electrode layer and the second electrode layer and surrounding the electrowetting microfluid medium layer. ### Claim 20 (depends on 5) The variable diaphragm of claim 5, further comprising a retaining wall between the first electrode layer and the second electrode layer and surrounding the electrowetting microfluid medium layer.