# US 8,786,646 B2 · Light-emitting chip, light-emitting device, print head and image forming apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,786,646 B2 - Document ID: US8786646B2 - Status: Granted - Kind: B2 - Application number: 13/084,058 - Filed: 2011-04-11 - Published: 2012-05-17 - Granted: 2014-07-22 - Earliest claimed: 2010-11-12 - Assignees: Fuji Xerox Co., Ltd. - Applicants: Taku Kinoshita; Yoshinao Kondoh; Seiji Ohno - Inventors: Taku Kinoshita; Yoshinao Kondoh; Seiji Ohno - Web page: https://patentgrep.com/patent/US8786646B2 ## CPC - G03G 15/04036: {Details of illuminating systems, e.g. lamps, reflectors (lamp housings for copying cameras, reflex exposure lighting G03B27/542)} - G03G 15/04054: {by LED arrays} - G03G 15/326: {by application of light, e.g. using a LED array} - H10H 29/10: Integrated devices comprising at least one light-emitting semiconductor component covered by group H10H20/00 (active-matrix LED displays H10H29/30) - H10H 29/14: comprising multiple light-emitting semiconductor components - H10H 20/813: having a plurality of light-emitting regions, e.g. multi-junction LEDs or light-emitting devices having photoluminescent regions within the bodies - G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY - H10H: INORGANIC LIGHT-EMITTING SEMICONDUCTOR DEVICES HAVING POTENTIAL BARRIERS ## Abstract A light-emitting chip includes: a substrate; plural light-emitting elements arrayed in line on the substrate, each of the light-emitting elements including a light-emitting region having a length in an array direction of the array different from a length in a direction orthogonal to the array direction; and a light-up current supplying interconnection including plural connecting portions, each of the connecting portions being provided on the light-emitting region of a corresponding one of the light-emitting elements in a shorter direction of the light-emitting region either the array direction or the direction orthogonal to the array direction, each of the connecting portions being connected to an electrode provided on the light-emitting region, the light-up current supplying interconnection supplying a current for lighting up to the plural light-emitting elements through the plural connecting portions. ## Claims ### Claim 1 A light-emitting chip comprising: a substrate; a plurality of light-emitting elements arrayed in line on the substrate, each of the light-emitting elements including a light-emitting region having a length in an array direction of the array different from a length in a direction orthogonal to the array direction; and a light-up current supplying interconnection including a plurality of connecting portions, each of the connecting portions being provided on the light-emitting region of a corresponding one of the light-emitting elements in a shorter direction of the light-emitting region either the array direction or the direction orthogonal to the array direction, each of the connecting portions being connected to an electrode provided on the light-emitting region, the light-up current supplying interconnection supplying a current for lighting up to the plurality of light-emitting elements through the plurality of connecting portions, wherein each of the plurality of light-emitting elements is isolated by a trench with a mesa structure, a longer direction of the light-emitting region being orthogonal to a shorter direction of the light-emitting region, the mesa structure including a forward mesa step extending in the longer direction of the light emitting region and the mesa structure including a reverse mesa step extending in the shorter direction of the light emitting region, and the light-up current supplying interconnection is arranged adjacent to the light-emitting region of each of the light-emitting elements, and has a reflecting surface reflecting light emitted with a spread so that the light is narrowed toward a direction perpendicular to the light-emitting region and in a direction away from the light-emitting elements. ### Claim 2 (depends on 1) The light-emitting chip according to claim 1, wherein the light-emitting region of each of the light-emitting elements has the length in the direction orthogonal to the array direction of the array longer than the length in the array direction, the light-up current supplying interconnection includes a primary portion extending in the array direction and a plurality of secondary portions branching from the primary portion, and the plurality of connecting portions included in the light-up current supplying interconnection are respectively connected to the plurality of secondary portions, and provided in the array direction of the array. ### Claim 3 (depends on 2) The light-emitting chip according to claim 2, wherein the plurality of secondary portions are provided for respective pairs each composed of two adjacent light-emitting elements of the plurality of light-emitting elements. ### Claim 4 (depends on 2) The light-emitting chip according to claim 2, wherein the primary portion and the plurality of connecting portions of the light-up current supplying interconnection are provided so as to cross the respective forward mesa step portions of the trenches isolating the plurality of light-emitting elements from each other. ### Claim 5 (depends on 3) The light-emitting chip according to claim 3, wherein the primary portion and the plurality of connecting portions of the light-up current supplying interconnection are provided so as to cross the respective forward mesa step portions of the trenches isolating the plurality of light-emitting elements from each other. ### Claim 6 (depends on 2) The light-emitting chip according to claim 2, wherein each of those edges of the primary portion and the plurality of secondary portions of the light-up current supplying interconnection has a reflecting surface facing a corresponding one of the plurality of light-emitting elements, the reflecting surface reflecting light emitted with a spread of the corresponding one of the light-emitting elements so that the light is narrowed toward a direction perpendicular to the light-emitting region and in a direction away from the light-emitting elements. ### Claim 7 (depends on 3) The light-emitting chip according to claim 3, wherein each of those edges of the primary portion and the plurality of secondary portions of the light-up current supplying interconnection has a reflecting surface facing a corresponding one of the plurality of light-emitting elements, the reflecting surface reflecting light emitted with a spread of the corresponding one of the light-emitting elements so that the light is narrowed toward a direction perpendicular to the light-emitting region and in a direction away from the light-emitting elements. ### Claim 8 (depends on 4) The light-emitting chip according to claim 4, wherein each of those edges of the primary portion and the plurality of secondary portions of the light-up current supplying interconnection has a reflecting surface facing a corresponding one of the plurality of light-emitting elements, the reflecting surface reflecting light emitted with a spread of the corresponding one of the light-emitting elements so that the light is narrowed toward a direction perpendicular to the light-emitting region and in a direction away from the light-emitting elements. ### Claim 9 (depends on 5) The light-emitting chip according to claim 5, wherein each of those edges of the primary portion and the plurality of secondary portions of the light-up current supplying interconnection has a reflecting surface facing a corresponding one of the plurality of light-emitting elements, the reflecting surface reflecting light emitted with a spread of the corresponding one of the light-emitting elements so that the light is narrowed toward a direction perpendicular to the light-emitting region and in a direction away from the light-emitting elements. ### Claim 10 (depends on 2) The light-emitting chip according to claim 2, wherein each of those edges of the primary portion and the plurality of secondary portions of the light-up current supplying interconnection has a surface facing a corresponding one of the plurality of light-emitting elements, the surface having a shape spreading in a direction perpendicular to the light-emitting region of the corresponding one of the light-emitting elements from an edge of the light-emitting region of the corresponding one of the light-emitting elements or a mesa step portion of the corresponding one of the light-emitting elements. ### Claim 11 (depends on 3) The light-emitting chip according to claim 3, wherein each of those edges of the primary portion and the plurality of secondary portions of the light-up current supplying interconnection has a surface facing a corresponding one of the plurality of light-emitting elements, the surface having a shape spreading in a direction perpendicular to the light-emitting region of the corresponding one of the light-emitting elements from an edge of the light-emitting region of the corresponding one of the light-emitting elements or a mesa step portion of the corresponding one of the light-emitting elements. ### Claim 12 (depends on 4) The light-emitting chip according to claim 4, wherein each of those edges of the primary portion and the plurality of secondary portions of the light-up current supplying interconnection has a surface facing a corresponding one of the plurality of light-emitting elements, the surface having a shape spreading in a direction perpendicular to the light-emitting region of the corresponding one of the light-emitting elements from an edge of the light-emitting region of the corresponding one of the light-emitting elements or a mesa step portion of the corresponding one of the light-emitting elements. ### Claim 13 (depends on 5) The light-emitting chip according to claim 5, wherein each of those edges of the primary portion and the plurality of secondary portions of the light-up current supplying interconnection has a surface facing a corresponding one of the plurality of light-emitting elements, the surface having a shape spreading in a direction perpendicular to the light-emitting region of the corresponding one of the light-emitting elements from an edge of the light-emitting region of the corresponding one of the light-emitting elements or a mesa step portion of the corresponding one of the light-emitting elements. ### Claim 14 (depends on 1) The light-emitting chip according to claim 1, wherein the light-up current supplying interconnection covers bottom and side surfaces of the trench, and has a shape that protrudes from a light-emitting surface of the light-emitting region in a direction of light-emission. ### Claim 15 A light-emitting chip comprising: a substrate; a plurality of light-emitting elements arrayed in line on the substrate, each of the light-emitting elements including a light-emitting region having a length in an array direction of the array different from a length in a direction orthogonal to the array direction; and a light-up current supplying interconnection including a plurality of connecting portions, each of the connecting portions extending on the light-emitting region of a corresponding one of the light-emitting elements in such a direction either the array direction or the direction orthogonal to the array direction that an area of the light-emitting region whose light is blocked is smaller, each of the connecting portions being connected to an electrode provided on the light-emitting region, the light-up current supplying interconnection supplying a current for lighting up to the plurality of light-emitting elements through the plurality of connecting portions, wherein each of the plurality of light-emitting elements is isolated by a trench with a mesa structure, a longer direction of the light-emitting region being orthogonal to a shorter direction of the light-emitting region, the mesa structure including a forward mesa step extending in the longer direction of the light emitting region and the mesa structure including a reverse mesa step extending in the shorter direction of the light emitting region, and the light-up current supplying interconnection is arranged adjacent to the light-emitting region of each of the light-emitting elements, and has a reflecting surface reflecting light emitted with a spread so that the light is narrowed toward a direction perpendicular to the light-emitting region and in a direction away from the light-emitting elements. ### Claim 16 A light-emitting device comprising: a plurality of light-emitting chips each including: a substrate; a plurality of light-emitting elements arrayed in line on the substrate, each of the light-emitting elements including a light-emitting region having a length in an array direction of the array different from a length in a direction orthogonal to the array direction; a plurality of transfer elements provided on the substrate so as to correspond to the respective light-emitting elements, each of the transfer elements designating a corresponding light-emitting element as a control target for lighting up or not lighting up by changing to an ON state; and a light-up current supplying interconnection including a plurality of connecting portions, each of the connecting portions being provided on the light-emitting region of a corresponding one of the light-emitting elements in a shorter direction of the light-emitting region either the array direction or the direction orthogonal to the array direction, each of the connecting portions being connected to an electrode provided on the light-emitting region, the light-up current supplying interconnection supplying a current for lighting up to the plurality of light-emitting elements through the plurality of connecting portions, each of the plurality of light-emitting elements is isolated by a trench with a mesa structure, a longer direction of the light-emitting region being orthogonal to a shorter direction of the light-emitting region, the mesa structure including a forward mesa step extending in the longer direction of the light emitting region and the mesa structure including a reverse mesa step extending in the shorter direction of the light emitting region, and the light-up current supplying interconnection is arranged adjacent to the light-emitting region of each of the light-emitting elements, and has a reflecting surface reflecting light emitted with a spread so that the light is narrowed toward a direction perpendicular to the light-emitting region and in a direction away from the light-emitting elements, and the light-emitting device further comprising: a transfer signal supplying unit transmitting transfer signals to the plurality of light-emitting chips for driving each of the transfer elements of the light-emitting chips so that the ON state sequentially propagates; and a light-up current supplying unit supplying a current for lighting up to the plurality of light-emitting chips. ### Claim 17 A print head comprising: a light-emitting unit; and an optical unit causing light emitted by the light-emitting unit to form an image, the light-emitting unit including a plurality of light-emitting chips each including: a substrate; a plurality of light-emitting elements arrayed in line on the substrate, each of the light-emitting elements including a light-emitting region having a length in an array direction of the array different from a length in a direction orthogonal to the array direction; a plurality of transfer elements provided on the substrate so as to correspond to the respective light-emitting elements, each of the transfer elements designating a corresponding light-emitting element as a control target for lighting up or not lighting up by changing to an ON state; each of the plurality of light-emitting elements is isolated by a trench with a mesa structure, a longer direction of the light-emitting region being orthogonal to a shorter direction of the light-emitting region, the mesa structure including a forward mesa step extending in the longer direction of the light emitting region and the mesa structure including a reverse mesa step extending in the shorter direction of the light emitting region, and a light-up current supplying interconnection including a plurality of connecting portions, each of the connecting portions being provided on the light-emitting region of a corresponding one of the light-emitting elements in a shorter direction of the light-emitting region either the array direction or the direction orthogonal to the array direction, each of the connecting portions being connected to an electrode provided on the light-emitting region, the light-up current supplying interconnection supplying a current for lighting up to the plurality of light-emitting elements through the plurality of connecting portions, the light-up current supplying interconnection is arranged adjacent to the light-emitting region of each of the light-emitting elements, and has a reflecting surface reflecting light emitted with a spread so that the light is narrowed toward a direction perpendicular to the light-emitting region and in a direction away from the light-emitting elements, and the light-emitting unit further including: a transfer signal supplying unit transmitting transfer signals to the plurality of light-emitting chips for driving each of the transfer elements of the light-emitting chips so that the ON state sequentially propagates; and a light-up current supplying unit supplying a current for lighting up to the plurality of light-emitting chips. ### Claim 18 An image forming apparatus comprising: an image carrier; a charging unit charging the image carrier; an exposure unit exposing the image carrier through an optical unit; a developing unit developing an electrostatic latent image exposed by the exposure unit and formed on the image carrier; and a transfer unit transferring an image developed on the image carrier to a transferred body, the exposure unit including a plurality of light-emitting chips each including: a substrate; a plurality of light-emitting elements arrayed in line on the substrate, each of the light-emitting elements including a light-emitting region having a length in an array direction of the array different from a length in a direction orthogonal to the array direction; a plurality of transfer elements provided on the substrate so as to correspond to the respective light-emitting elements, each of the transfer elements designating a corresponding light-emitting element as a control target for lighting up or not lighting up by changing to an ON state; each of the plurality of light-emitting elements is isolated by a trench with a mesa structure, a longer direction of the light-emitting region being orthogonal to a shorter direction of the light-emitting region, the mesa structure including a forward mesa step extending in the longer direction of the light emitting region and the mesa structure including a reverse mesa step extending in the shorter direction of the light emitting region, and a light-up current supplying interconnection including a plurality of connecting portions, each of the connecting portions being provided on the light-emitting region of a corresponding one of the light-emitting elements in a shorter direction of the light-emitting region either the array direction or the direction orthogonal to the array direction, each of the connecting portions being connected to an electrode provided on the light-emitting region, the light-up current supplying interconnection supplying a current for lighting up to the plurality of light-emitting elements through the plurality of connecting portions, the light-up current supplying interconnection is arranged adjacent to the light-emitting region of each of the light-emitting elements, and has a reflecting surface reflecting light emitted with a spread so that the light is narrowed toward a direction perpendicular to the light-emitting region and in a direction away from the light-emitting elements, and the exposure unit further including: a transfer signal supplying unit transmitting transfer signals to the plurality of light-emitting chips for driving each of the transfer elements of the light-emitting chips so that the ON state sequentially propagates; and a light-up current supplying unit supplying a current for lighting up to the plurality of light-emitting chips.