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公开(公告)号：US11333532B1
公开(公告)日：2022-05-17
申请号：US17118438
申请日：2020-12-10
Applicant: PixArt Imaging Inc.
Inventor： Kuan-Choong Shim , Gim-Eng Chew
Abstract: There is provided a light control circuit including a light detector, a frequency detector, an error amplifier, an NMOS driver and a light source. The frequency detector identifies a signal frequency according to detected voltage signals outputted by the light detector and generates a control signal accordingly. The NMOS driver changes a drive current of the light source according to an output of the error amplifier. The error amplifier changes a bandwidth thereof according to the control signal from the frequency detector to regulate a response time of the drive current of the light source.
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公开(公告)号：US10728972B2
公开(公告)日：2020-07-28
申请号：US16579121
申请日：2019-09-23
Applicant: PixArt Imaging Inc.
Inventor： Kuan-Choong Shim , Gim-Eng Chew
Abstract: There is provided a light control circuit including a detected voltage generating circuit, a reference voltage generating circuit, an error amplifier, an NMOS driver and a light source. The detected voltage generating circuit outputs a detected voltage to a first input terminal of the error amplifier. The reference voltage generating circuit outputs a reference voltage to a second input terminal of the error amplifier. The NMOS driver changes a drive current of the light source according to an output of the error amplifier.
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公开(公告)号：US10187948B1
公开(公告)日：2019-01-22
申请号：US15993798
申请日：2018-05-31
Applicant: PixArt Imaging Inc.
Inventor： Kuan-Choong Shim , Gim-Eng Chew
Abstract: There is provided a light control circuit including a detected voltage generating circuit, a reference voltage generating circuit, an error amplifier, an NMOS driver and a light source. The detected voltage generating circuit outputs a detected voltage to a first input terminal of the error amplifier. The reference voltage generating circuit outputs a reference voltage to a second input terminal of the error amplifier. The NMOS driver changes a drive current of the light source according to an output of the error amplifier.
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公开(公告)号：US20240361158A1
公开(公告)日：2024-10-31
申请号：US18677941
申请日：2024-05-30
Applicant: PixArt Imaging Inc.
Inventor： Kuan-Choong Shim , Meng-Yee Lim , Priscilla Tze-Wei Goh , Gim-Eng Chew
CPC classification number: G01D5/34723 , G01D5/3473 , G01D18/001 , G01D2205/20
Abstract: There is provided an optical encoding system including a photodiode array and a code disk opposite to each other. The photodiode array includes a detection photodiode group and a calibration photodiode group. If there is a position deviation between the photodiode array and the code disk, whether to utilize detection signals of the calibration photodiode group is determined according to phase shifts between detection signals outputted by the detection photodiode group so as to eliminate the phase shifts.
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Patent Agency Ranking
公开(公告)号：US12117318B2
公开(公告)日：2024-10-15
申请号：US18129077
申请日：2023-03-31
Applicant: PIXART IMAGING INC.
Inventor： Chung-Min Thor , Kuan-Choong Shim
IPC: G01D5/347
CPC classification number: G01D5/34715
Abstract: There is provided an optical encoder including an encoding medium and a substrate. The encoding medium has a relative movement with respect to the substrate in a predetermined direction. The substrate includes an index photodiode and two control photodiodes. The index photodiode is arranged between the two control photodiodes along the predetermined direction. The output signals of the two control photodiodes are for controlling ON/OFF of gain regulation on an output signal of the index photodiode so as to turn on the gain regulation within an interval during which the index photodiode does not generate an index pulse but to turn off the gain regulation within an interval during which the index photodiode generates the index pulse.
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公开(公告)号：US11885828B2
公开(公告)日：2024-01-30
申请号：US17582194
申请日：2022-01-24
Applicant: PIXART IMAGING INC.
Inventor： Chung-Min Thor , Kuan-Choong Shim
CPC classification number: G01P3/36 , G01P3/486 , G01D5/249 , G01D5/34 , G01D5/34715
Abstract: There is provided an optical encoder including a phase shifter circuit and a multiple hysteresis comparators. The phase shifter circuit receives four input signals, and outputs multiple phase shifted signals based on the four input signals. Each of the multiple hysteresis comparators uses a changeable operation hysteresis level to compare a couple of phase shifted signals among the multiple phase shifted signals, wherein the changeable operation hysteresis level is determined corresponding to a signal frequency of the four input signals.
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公开(公告)号：US11709077B2
公开(公告)日：2023-07-25
申请号：US17545116
申请日：2021-12-08
Applicant: PixArt Imaging Inc.
Inventor： Kuan-Choong Shim , Gim-Eng Chew
IPC: G01D5/347
CPC classification number: G01D5/3473 , G01D5/34707
Abstract: There is provided an optical encoder including a photodiode array and a code disk opposite to each other. The photodiode array includes at least three sets of position photodiodes and two index photodiodes arranged transversally. The two index photodiodes are adjacently arranged at the same side of the at least three sets of position photodiodes. A first set of position photodiodes and a last set of position photodiodes of the at least three sets of position photodiodes are partially covered to alleviate the total harmonic distortion. The rest position photodiodes of the at least three sets of position photodiodes other than the first and last sets of position photodiodes are not covered.
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公开(公告)号：US11237024B2
公开(公告)日：2022-02-01
申请号：US16583972
申请日：2019-09-26
Applicant: PixArt Imaging Inc.
Inventor： Kuan-Choong Shim , Gim-Eng Chew
IPC: G01D5/347
Abstract: There is provided an optical encoder including a photodiode array and a code disk opposite to each other. The photodiode array includes at least three sets of position photodiodes and two index photodiodes arranged transversally. The two index photodiodes are adjacently arranged at the same side of the at least three sets of position photodiodes. A first set of position photodiodes and a last set of position photodiodes of the at least three sets of position photodiodes are partially covered to alleviate the total harmonic distortion. The rest position photodiodes of the at least three sets of position photodiodes other than the first and last sets of position photodiodes are not covered.
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公开(公告)号：US11108385B1
公开(公告)日：2021-08-31
申请号：US16907948
申请日：2020-06-22
Applicant: PixArt Imaging Inc.
Inventor： Chung-Min Thor , Kuan-Choong Shim , Gim-Eng Chew
Abstract: There is provided a phase shifter circuit of an optical encoder that receives four signals generated from photodiodes. The phase shifter circuit includes four resistor strings each coupled to two of the four signals having a 90-degrees phase pitch. By taping out different numbers of signals at different tape-out nodes of each of the four resistor strings, the phase shifter circuit is adapted to output signals for different interpolation factors without changing the mask set.
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