# US 10,121,613 B2 · Keyswitch device, keyboard, and membrane circuit board > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,121,613 B2 - Document ID: US10121613B2 - Status: Granted - Kind: B2 - Application number: 15/235,123 - Filed: 2016-08-12 - Published: 2017-10-12 - Granted: 2018-11-06 - Earliest claimed: 2016-04-12 - Assignees: Chicony Electronics Co., Ltd. - Applicants: Chicony Electronics Co., Ltd. - Inventors: Pao-Chin Alan Chen; Ching-Cheng Tsai; Tsung-Min Chen; Pai-Hsiang Wang; Chun-Wei Lu - Web page: https://patentgrep.com/patent/US10121613B2 ## CPC - H01H 13/703: characterised by spacers between contact carrying layers - H01H 13/023: {Light-emitting indicators (for multi-layer switches H01H13/83)} - H01H 13/83: characterised by legends, e.g. Braille, liquid crystal displays, light emitting or optical elements - H05K 1/0274: {Optical details, e.g. printed circuits comprising integral optical means (H05K1/0269 takes precedence; coupling light guides with opto-electronic components G02B6/42)} - H05K 1/18: structurally associated with non-printed electric components (H05K1/16 takes precedence) - H01H 2211/00: Spacers - H01H 2219/06: Reflector - H01H 2219/062: Light conductor - H01H 2223/002: sealed - H01H 2227/002: Layer thickness - H05K 2201/0108: Transparent - H05K 2201/10106: Light emitting diode [LED] - H05K 2201/2054: Light-reflecting surface, e.g. conductors, substrates, coatings, dielectrics - H01H: ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES (contact cables H01B7/10; electrolytic self-interrupters H01G9/18; emergency protective circuit arrangements H02H; switching by electronic means without contact-making H03K17/00) - H05K: PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS ## Abstract A keyswitch device includes a base plate, a membrane circuit board, a light source, and a keyswitch assembly. The membrane circuit board is disposed on the base plate and includes a reflective film layer, a transmissive film layer, and a light guide spacer. The reflective film layer is located on the base plate. The transmissive film layer is located over the reflective film layer. The light guide spacer has an accommodating space. The reflective film layer and the transmissive film layer are respectively located at opposite sides of the light guide spacer. The light source is disposed between the reflective film layer and the transmissive film layer and located in the accommodating space. The keyswitch assembly is disposed on the membrane circuit board. ## Claims ### Claim 1 A keyswitch device, comprising: a base plate; a membrane circuit board disposed on the base plate, the membrane circuit board comprising: a reflective film layer located on the base plate; a transmissive film layer located over the reflective film layer; a light guide spacer film layer having an accommodating space, wherein the reflective film layer and the transmissive film layer are respectively located at opposite sides of the light guide spacer film layer; and a power supply circuit, a light source sandwiched between the reflective film layer and the transmissive film layer, located in the accommodating space, and spaced apart from the base plate, wherein the light source is powered by the power supply circuit; and a keyswitch assembly disposed on the membrane circuit board. ### Claim 2 (depends on 1) The keyswitch device of claim 1, wherein the light source is disposed on the reflective film layer and emits light toward the transmissive film layer. ### Claim 3 (depends on 1) The keyswitch device of claim 1, wherein the light source is disposed on the transmissive film layer and emits light toward the reflective film layer. ### Claim 4 (depends on 1) The keyswitch device of claim 1, wherein the light guide spacer film layer further has a through hole located right under the keyswitch assembly, the reflective film layer comprises a switch circuit, the transmissive film layer comprises a conductive contact, and the conductive contact is configured to contact the switch circuit via the through hole. ### Claim 5 (depends on 1) The keyswitch device of claim 1, wherein the light guide spacer film layer has a plurality of light-reflecting portions. ### Claim 6 (depends on 1) The keyswitch device of claim 1, wherein the light source is powered by a copper foil wire. ### Claim 7 (depends on 1) The keyswitch device of claim 1, wherein the transmissive film layer comprises: a transparent substrate disposed with a reflective coating and a shielding coating to form a transmissive area, wherein an orthogonal projection of the keyswitch assembly projected on the membrane circuit board covers the transmissive area. ### Claim 8 (depends on 7) The keyswitch device of claim 7, wherein an orthogonal projection of the accommodating space projected on the transmissive film layer overlaps the reflective film layer. ### Claim 9 (depends on 7) The keyswitch device of claim 7, wherein the transparent substrate has a top surface facing the keyswitch assembly, the reflective coating is disposed on the top surface, and the shielding coating covers the reflective coating. ### Claim 10 (depends on 7) The keyswitch device of claim 7, wherein the transparent substrate has a top surface and bottom surface, the top surface faces the keyswitch assembly, the bottom surface faces the light guide spacer film layer, the shielding coating is disposed on the top surface, and the reflective coating is disposed on the bottom surface. ### Claim 11 A keyboard, comprising: a base plate; a membrane circuit board disposed on the base plate, the membrane circuit board comprising: a reflective film layer located on the base plate; a transmissive film layer located over the reflective film layer; a light guide spacer film layer having a plurality of accommodating spaces, wherein the reflective film layer and the transmissive film layer are respectively located at opposite sides of the light guide spacer film layer; and a power supply circuit; a plurality of light sources sandwiched between the reflective film layer and the transmissive film layer, respectively located in the accommodating spaces, and spaced apart from the base plate, wherein the light sources are powered by the power supply circuit; and a plurality of keyswitch assemblies disposed on the membrane circuit board. ### Claim 12 (depends on 11) The keyboard device of claim 11, wherein the light sources are disposed on the reflective film layer and emit lights toward the transmissive film layer. ### Claim 13 (depends on 11) The keyboard device of claim 11, wherein the light sources are disposed on the transmissive film layer and emit lights toward the reflective film layer. ### Claim 14 (depends on 11) The keyboard device of claim 11, wherein the light guide spacer film layer further has a plurality of through holes located right under the keyswitch assemblies respectively, the reflective film layer comprises a switch circuit, the transmissive film layer comprises a plurality of conductive contacts, and the conductive contacts are configured to contact the switch circuit respectively via the through holes. ### Claim 15 (depends on 11) The keyboard device of claim 11, wherein the light guide spacer film layer has a plurality of light-reflecting portions. ### Claim 16 (depends on 11) The keyboard device of claim 11, wherein the light sources are powered by a copper foil wire. ### Claim 17 (depends on 11) The keyboard device of claim 11, wherein the transmissive film layer comprises: a transparent substrate disposed with a reflective coating and a shielding coating forming a plurality of transmissive areas, wherein orthogonal projections of the keyswitch assemblies projected on the membrane circuit board cover the transmissive areas. ### Claim 18 (depends on 17) The keyboard device of claim 17, wherein orthogonal projections of the accommodating spaces projected on the transmissive film layer overlap the reflective film layer. ### Claim 19 (depends on 17) The keyboard device of claim 17, wherein the transparent substrate has a top surface facing the keyswitch assemblies, the reflective coating is disposed on the top surface, and the shielding coating covers the reflective coating. ### Claim 20 (depends on 17) The keyboard device of claim 17, wherein the transparent substrate has a top surface and bottom surface, the top surface faces the keyswitch assemblies, the bottom surface faces the light guide spacer film layer, the shielding coating is disposed on the top surface, and the reflective coating is disposed on the bottom surface. ### Claim 21 A membrane circuit board, comprising: a reflective film layer; a transmissive film layer located over the reflective film layer; a light guide spacer film layer having an accommodating space, wherein the reflective film layer and the transmissive film layer are respectively located at opposite sides of the light guide spacer film layer; a power supply circuit: and a light source sandwiched between the reflective film layer and the transmissive film layer and located in the accommodating space, wherein the light source is powered by the power supply circuit. ### Claim 22 (depends on 21) The membrane circuit board of claim 21, wherein the light source is disposed on the reflective film layer and emits light toward the transmissive film layer. ### Claim 23 (depends on 21) The membrane circuit board of claim 21, wherein the light source is disposed on the transmissive film layer and emits light toward the reflective film layer. ### Claim 24 (depends on 21) The membrane circuit board of claim 21, wherein the light guide spacer film layer further has a through hole, the reflective film layer comprises a switch circuit, the transmissive film layer comprises a conductive contact, and the conductive contact is configured to contact the switch circuit via the through hole. ### Claim 25 (depends on 21) The membrane circuit board of claim 21, wherein the light guide spacer film layer has a plurality of light-reflecting portions. ### Claim 26 (depends on 21) The membrane circuit board of claim 21, wherein the light source is powered by a copper foil wire. ### Claim 27 (depends on 21) The membrane circuit board of claim 21, wherein the transmissive film layer comprises: a transparent substrate disposed with a reflective coating and a shielding coating to form a transmissive area, wherein an orthogonal projection of the accommodating space projected on the transmissive film layer overlaps the reflective film layer. ### Claim 28 (depends on 27) The membrane circuit board of claim 27, wherein the transparent substrate has a top surface, the reflective coating is disposed on the top surface, and the shielding coating covers the reflective coating. ### Claim 29 (depends on 27) The membrane circuit board of claim 27, wherein the transparent substrate has a top surface and bottom surface, the bottom surface faces the light guide spacer film layer, the shielding coating is disposed on the top surface, and the reflective coating is disposed on the bottom surface.