# US 12,601,777 B2 · Inspection system and method for inspecting light-emitting diodes > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,601,777 B2 - Document ID: US12601777B2 - Status: Granted - Kind: B2 - Application number: 18/334,387 - Filed: 2023-06-14 - Published: 2024-04-04 - Granted: 2026-04-14 - Earliest claimed: 2022-09-30 - Assignees: Industrial Technology Research Institute - Applicants: Industrial Technology Research Institute - Inventors: Yan-Rung Lin; Chung-Lun Kuo; Chia-Liang Yeh - Web page: https://patentgrep.com/patent/US12601777B2 ## CPC - G01R 31/2635: {Testing light-emitting diodes, laser diodes or photodiodes} - G01R 31/44: Testing lamps - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) ## Abstract An inspection system includes an excitation light source, a voltage-sensing film, an illumination light source, an image capture device. The excitation light source provides an excitation beam to light-emitting diodes to generate open-circuit voltages. The voltage-sensing film is at a top side of the light-emitting diodes and includes a voltage-sensing medium layer and a first electrode layer. The first electrode layer is in the voltage-sensing medium layer to provide a gain effect of the open-circuit voltages, so that the voltage-sensing medium layer senses the open-circuit voltages, and a display of the voltage-sensing medium layer is changed with a portion or all of the open-circuit voltages. The illumination light source provides an illumination beam to the voltage-sensing film to generate a sensing image according to a display change. The image capture device is on a transmission path of the sensing image and receives the sensing image to generate an inspection result. ## Claims ### Claim 1 An inspection system, configured to inspect a plurality of light-emitting diodes, comprising: an excitation light source configured to provide an excitation beam to the plurality of light-emitting diodes so that the plurality of light-emitting diodes generate a plurality of open-circuit voltages; a voltage-sensing film located at a top side of the plurality of light-emitting diodes and configured to generate a display change according to a driving voltage, wherein the driving voltage is derived from at least the plurality of open-circuit voltages, and the voltage-sensing film comprises: a voltage-sensing medium layer; and a first electrode layer disposed in the voltage-sensing medium layer to provide a gain effect of the plurality of open-circuit voltages, so that the voltage-sensing medium layer senses the plurality of open-circuit voltages, wherein the first electrode layer comprises a plurality of strip electrodes arranged at intervals along an arrangement direction, and an external bias voltage is provided to the plurality of strip electrodes such that a voltage difference is formed between adjacent strip electrodes; an illumination light source providing an illumination beam to the voltage-sensing film to generate a sensing image according to the display change; and an image capture device disposed on a transmission path of the sensing image and configured to receive the sensing image to generate an inspection result, wherein an electric field corresponding to the plurality of open-circuit voltages has a direction parallel to an extending direction of a substrate with the plurality of light-emitting diodes. ### Claim 2 (depends on 1) The inspection system of claim 1, wherein the voltage-sensing medium layer is an in-plane switching liquid crystal, a fringe field switching liquid crystal, a homogeneously aligned bend liquid crystal, or a transverse bend mode vertical alignment liquid crystal. ### Claim 3 (depends on 1) The inspection system of claim 1, wherein an arrangement direction of the first electrode layer is perpendicular or parallel to an arrangement direction of electrodes in the plurality of light-emitting diodes. ### Claim 4 (depends on 1) The inspection system of claim 1, wherein the voltage-sensing film comprises: a first substrate; and a second substrate, wherein the voltage-sensing medium layer is connected between the first substrate and the second substrate, and the first electrode layer is connected to the first substrate or the second substrate. ### Claim 5 (depends on 4) The inspection system of claim 4, wherein the first electrode layer is connected to the first substrate, and the plurality of strip electrodes are activated to provide an external bias voltage. ### Claim 6 (depends on 5) The inspection system of claim 5, wherein the plurality of light-emitting diodes comprise a plurality of device electrodes, and a number of the plurality of strip electrodes is an integer multiple of a number of the plurality of device electrodes. ### Claim 7 (depends on 4) The inspection system of claim 4, wherein the first electrode layer is connected to the second substrate, the first electrode layer comprises a plurality of floating electrodes arranged at intervals along an arrangement direction, and the plurality of floating electrodes generate a induced voltage according to the plurality of open-circuit voltages. ### Claim 8 (depends on 7) The inspection system of claim 7, wherein the plurality of light-emitting diodes comprise a plurality of device electrodes, and an interval width of the plurality of floating electrodes is less than an interval width of two device electrodes. ### Claim 9 (depends on 8) The inspection system of claim 8, wherein the plurality of floating electrodes and the plurality of device electrodes are overlapped in a stacking direction. ### Claim 10 (depends on 4) The inspection system of claim 4, wherein the voltage-sensing film further comprises a second electrode layer disposed on the voltage-sensing medium layer, the first electrode layer is connected to the first substrate, and the second electrode layer is connected to the second substrate. ### Claim 11 (depends on 10) The inspection system of claim 10, wherein an electrode arrangement direction of the first electrode layer is perpendicular or parallel to an electrode arrangement direction of the second electrode layer. ### Claim 12 (depends on 4) The inspection system of claim 4, wherein the voltage-sensing film further comprises a reflective layer disposed at an upper surface or a lower surface of the second substrate. ### Claim 13 (depends on 1) The inspection system of claim 1, further comprising: a light-splitting element disposed on a transmission path of the illumination beam and configured to reflect the illumination beam to the voltage-sensing film and allowing the sensing image from the voltage-sensing film to pass through. ### Claim 14 (depends on 1) The inspection system of claim 1, wherein the excitation light source and the illumination light source are located at a bottom side and a top side of the plurality of light-emitting diodes, respectively. ### Claim 15 (depends on 1) The inspection system of claim 1, wherein the excitation light source and the illumination light source are substantially a same light-emitting device, and the excitation beam is the same as the illumination beam and transmitted to the plurality of light-emitting diodes from a same direction. ### Claim 16 (depends on 1) The inspection system of claim 1, wherein the excitation light source and the illumination light source are located at a same side of the plurality of light-emitting diodes, and the light-splitting element is also located on a transmission path of the excitation beam and configured to reflect the excitation beam to the voltage-sensing film. ### Claim 17 (depends on 1) The inspection system of claim 1, further comprising: a light filter disposed on a transmission path of the illumination beam and located between the image capture device and the voltage-sensing film and configured to filter the excitation beam or a light generate by photoluminescence. ### Claim 18 (depends on 17) The inspection system of claim 17, wherein the light filter is a high-pass filter or a bandpass filter. ### Claim 19 (depends on 17) The inspection system of claim 17, wherein the light filter is a light attenuator. ### Claim 20 (depends on 1) The inspection system of claim 1, further comprising: a processing element electrically connected to the image capture device and obtaining the open-circuit voltages of the plurality of light-emitting diodes according to the inspection result. ### Claim 21 (depends on 1) The inspection system of claim 1, wherein an electric field corresponding to a driving voltage of the voltage-sensing medium layer has a direction parallel to a direction of electric field corresponding to the plurality of open-circuit voltages of the plurality of light-emitting diodes. ### Claim 22 A method for inspecting light-emitting diodes, configured to inspect a plurality of light-emitting diodes, the method comprising: providing an excitation beam to the plurality of light-emitting diodes so that the plurality of light-emitting diodes generate a plurality of open-circuit voltages, wherein an electric field corresponding to the plurality of open-circuit voltages has a direction parallel to an extending direction of a substrate with the plurality of light-emitting diodes; providing an open-circuit voltage gain effect to a voltage-sensing medium layer of a voltage-sensing film; providing a first electrode layer comprising a plurality of strip electrodes arranged at intervals along an arrangement direction disposed in the voltage-sensing medium layer; applying an external bias voltage to the plurality of strip electrodes such that a voltage difference is formed between adjacent strip electrodes; sensing the plurality of open-circuit voltages via the voltage-sensing medium layer, and a display of the voltage-sensing medium layer is changed with a portion or all of the plurality of open-circuit voltages, so that the voltage-sensing film generates a display change; providing an illumination beam to the voltage-sensing film to generate a sensing image according to the display change; and capturing the sensing image to generate an inspection result. ### Claim 23 (depends on 22) The method for inspecting the light-emitting diodes of claim 22, wherein the method of providing the open-circuit voltage gain effect to the voltage-sensing medium layer of the voltage-sensing film further comprises: providing an applied bias voltage upon activation. ### Claim 24 (depends on 22) The method for inspecting the light-emitting diodes of claim 22, wherein the method of providing the open-circuit voltage gain effect to the voltage-sensing medium layer of the voltage-sensing film further comprises: generating a induced voltage according to the plurality of open-circuit voltages. ### Claim 25 (depends on 22) The method for inspecting the light-emitting diodes of claim 22, wherein the method of providing the illumination beam to the voltage-sensing film to generate the sensing image according to the display change further comprises: providing the illumination beam through the voltage-sensing medium layer to generate the sensing image; and reflecting the sensing image to the image capture device. ### Claim 26 (depends on 25) The method for inspecting the light-emitting diodes of claim 25, further comprising: generating the inspection result according to the sensing image. ### Claim 27 (depends on 22) The method for inspecting the light-emitting diodes of claim 22, further comprising: obtaining the plurality of open-circuit voltages of the plurality of light-emitting diodes according to the inspection result.