# US 12,015,895 B2 · Speaker > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,015,895 B2 - Document ID: US12015895B2 - Status: Granted - Kind: B2 - Application number: 17/919,715 - Filed: 2021-10-15 - Published: 2023-05-11 - Granted: 2024-06-18 - Earliest claimed: 2020-11-10 - Assignees: Panasonic Intellectual Property Management Co., Ltd. - Applicants: Panasonic Intellectual Property Management Co., Ltd. - Inventors: Kazuki Honda; Masashi Nishida; Junichi Ikeda; Ippei Kiyama - Web page: https://patentgrep.com/patent/US12015895B2 ## CPC - H04R 1/24: Structural combinations of separate transducers or of two parts of the same transducer and responsive respectively to two or more frequency ranges - H04R 1/38: in which sound waves act upon both sides of a diaphragm and incorporating acoustic phase-shifting means, e.g. pressure-gradient microphone - H04R 7/127: {dome-shaped} - H04R 1/30: Combinations of transducers with horns, e.g. with mechanical matching means {, i.e. front-loaded horns}(horns in general G10K; {transducer enclosures or mountings using a back-loaded horn H04R1/2861; application of horns as guiding means to obtain a predetermined directivity characteristic H04R1/345}) - H04R 7/20: Securing diaphragm or cone resiliently to support by flexible material, springs, cords, or strands - H04R 9/06: Loudspeakers - H04R 2201/34: Directing or guiding sound by means of a phase plug - H04R 2400/13: Use or details of compression drivers - H04R: LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; ELECTRIC HEARING AIDS; PUBLIC ADDRESS SYSTEMS (producing sounds with frequency not determined by supply frequency G10K) ## Abstract A speaker includes: a diaphragm having a dome shape; a tubular member having the diaphragm disposed inside, and having an inner diameter increasing toward a front; and a phase plug. The phase plug includes: a front surface, a rear surface facing a central portion on a front surface of the diaphragm at a constant interval in parallel, and a side surface connecting the front surface and the rear surface. A front surface of the phase plug is larger than a rear surface of the phase plug as viewed in a front-rear direction of a speaker. At least a part of a side surface of the phase plug has an inclined surface extending outward while extending forward, faces an inner circumferential surface of the tubular member and a front surface of the diaphragm, and directs a sound wave generated from the diaphragm toward an inner circumferential surface of the tubular member. ## Claims ### Claim 1 A speaker comprising: a diaphragm having a dome shape curved forward in a protruding manner; a tubular member having the diaphragm disposed inside, the tubular member having an inner diameter increasing toward a front; and a phase plug disposed in front of a front surface of the diaphragm, wherein the phase plug includes: a front surface facing forward, a rear surface facing a central portion on the front surface of the diaphragm at a constant interval in parallel with the central portion, and a side surface connecting the front surface and the rear surface, wherein the front surface of the phase plug is larger than the rear surface of the phase plug as viewed in a front-rear direction of the speaker, and wherein at least a part of the side surface of the phase plug has an inclined surface that extends outward while extending forward, faces an inner circumferential surface of the tubular member and the front surface of the diaphragm, and directs a sound wave generated from the diaphragm toward the inner circumferential surface of the tubular member. ### Claim 2 (depends on 1) The speaker according to claim 1, wherein the inclined surface of the phase plug is a curved surface curved outward in a protruding manner. ### Claim 3 (depends on 1) The speaker according to claim 1, wherein the phase plug includes a plurality of ribs protruding from the side surface of the phase plug toward the front surface of the diaphragm, and wherein each of the plurality of ribs includes a facing surface that faces the front surface of the diaphragm in parallel with the front surface of the diaphragm at the constant interval. ### Claim 4 (depends on 3) The speaker according to claim 3, wherein each of the plurality of ribs has a shape in which a wall thickness increases toward the front. ### Claim 5 (depends on 3) The speaker according to claim 3, wherein the facing surface of each of the plurality of ribs has a shape in which a width decreases toward an outer side as viewed in the front-rear direction of the speaker. ### Claim 6 (depends on 3) The speaker according to claim 3, wherein the plurality of ribs protrude outward beyond an outer circumferential edge of the front surface of the phase plug as viewed in the front-rear direction of the speaker. ### Claim 7 (depends on 1) The speaker according to claim 1 wherein the front surface of the phase plug is a conical protruding surface having a conical surface curved inward in a protruding manner. ### Claim 8 (depends on 1) The speaker according to claim 1, wherein the diaphragm having a dome shape is a diaphragm of a tweeter, and wherein the tubular member is a diaphragm of a woofer. ### Claim 9 A speaker comprising: a diaphragm having a dome shape curved forward in a protruding manner; and a phase plug disposed in front of a front surface of the diaphragm, wherein the phase plug includes: a front surface facing forward, a rear surface facing a central portion on the front surface of the diaphragm at a constant interval in parallel with the central portion, and a side surface connecting the front surface and the rear surface, wherein the side surface of the phase plug is located on inside of an outer circumferential edge of the front surface of the phase plug as viewed in a front-rear direction of the speaker, wherein the phase plug includes a plurality of ribs on the side surface of the phase plug, wherein each of the plurality of ribs includes a facing surface that faces the front surface of the diaphragm at the constant interval in parallel with the front surface of the diaphragm, and wherein each of the plurality of ribs protrudes outward beyond an outer circumferential edge of the front surface of the phase plug as viewed in the front-rear direction of the speaker. ### Claim 10 (depends on 9) The speaker according to claim 9, wherein at least a part of the side surface of the phase plug includes an inclined surface extending outward while extending forward, and wherein each of the plurality of ribs protrudes from the side surface toward the front surface of the diaphragm. ### Claim 11 (depends on 1) The speaker according to claim 1, wherein at least a part of the side surface of the phase plug has a first wall surface and a second wall surface, wherein the first wall surface extends at least in the front-rear direction of the speaker from the rear surface, and wherein the second wall surface has an eaves-soffit shape, extends at least outward from the first wall surface, and is connected to the inclined surface.