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公开(公告)号：US20200022235A1
公开(公告)日：2020-01-16
申请号：US16579121
申请日：2019-09-23
Applicant: PixArt Imaging Inc.
Inventor： KUAN-CHOONG SHIM , GIM-ENG CHEW
IPC: H05B33/08
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：US20230208412A1
公开(公告)日：2023-06-29
申请号：US18111602
申请日：2023-02-20
Applicant: PixArt Imaging Inc.
Inventor： SWEE-LIN THOR , GIM-ENG CHEW
CPC classification number: H03K5/24 , G01D5/34715 , H03K5/13 , G01D5/34792 , H03K2005/00052
Abstract: There is provided an optical encoder including a phase shifter circuit, two multiplexers, two digital circuits and four comparators. The phase shifter circuit receives signals from an amplifier and outputs multiple phase shifted signals. Each of the two multiplexers receives a half of the multiple phase shifted signals and outputs two pairs of phase shifted signals, each pair having 180 degrees phase difference, respectively to two comparators connected thereto. Each of the two digital circuits controls the corresponding multiplexer to select the two pairs of phase shifted signals from the half of the multiple phase shifted signals.
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公开(公告)号：US20230349732A1
公开(公告)日：2023-11-02
申请号：US18219729
申请日：2023-07-10
Applicant: PixArt Imaging Inc.
Inventor： KUAN-CHOONG SHIM , GIM-ENG CHEW , PRISCILLA TZE-WEI GOH , MENG-YEE LIM
IPC: G01D5/347
CPC classification number: G01D5/3473
Abstract: There is provided an optical encoder including an encoding medium, multiple photodiodes and a signal processing circuit. The encoding medium includes an index track. The index track includes a first index pattern and a second index pattern. The multiple photodiodes include a first index photodiode, a second index photodiode and a reference index photodiode for receiving modulated light from the first index pattern and the second index pattern. When the first index photodiode is aligned with the first index pattern and the second index photodiode is aligned with the second index pattern, the signal processing circuit outputs a triggering signal.
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Patent Agency Ranking
公开(公告)号：US20230314187A1
公开(公告)日：2023-10-05
申请号：US18206584
申请日：2023-06-06
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：US20230408304A1
公开(公告)日：2023-12-21
申请号：US18239773
申请日：2023-08-30
Applicant: PixArt Imaging Inc.
Inventor： KUAN-CHOONG SHIM , GIM-ENG CHEW
CPC classification number: G01D5/34715 , G01D5/3473 , G01D5/24466 , G01D5/24457 , G01D5/24428 , G01D5/24471 , G01D5/24476
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：US20220276075A1
公开(公告)日：2022-09-01
申请号：US17742999
申请日：2022-05-12
Applicant: PixArt Imaging Inc.
Inventor： SWEE-LIN THOR , GIM-ENG CHEW
Abstract: There is provided an optical encoder including a phase shifter circuit, two multiplexers, two digital circuits and four comparators. The phase shifter circuit receives signals from an amplifier and outputs multiple phase shifted signals. Each of the two multiplexers receives a half of the multiple phase shifted signals and outputs two pairs of phase shifted signals, each pair having 180 degrees phase difference, respectively to two comparators connected thereto. Each of the two digital circuits controls the corresponding multiplexer to select the two pairs of phase shifted signals from the half of the multiple phase shifted signals.
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公开(公告)号：US20220221312A1
公开(公告)日：2022-07-14
申请号：US17710096
申请日：2022-03-31
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：US20220099464A1
公开(公告)日：2022-03-31
申请号：US17545116
申请日：2021-12-08
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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