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公开(公告)号：DE69231585T2
公开(公告)日：2001-05-31
申请号：DE69231585
申请日：1992-05-08
Applicant: BIO RAD LABORATORIES
Inventor： CURBELO RAUL , JOHNSON B
Abstract: A fast and effective way to step a relative position quantity by a reference interval. Each step in relative position includes open-loop and closed-loop control intervals. An actuator (27) capable of changing the relative position and a closed loop servo (17) that acts on the actuator (27) to keep the relative position centered on the nearest of a series of reference values. The servo (17) has locked the relative position to a particular initial reference value. First, the actuator (27) is caused to change the relative position by an amount approximately equal to the reference interval in a manner that the servo (17) cannot track the change, such as by disabling the servo (17). Servo control is then re-established, at which point the servo (17) operates to keep the relative position centered on the nearest reference value.
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公开(公告)号：GB2341923A
公开(公告)日：2000-03-29
申请号：GB0001154
申请日：1998-08-06
Applicant: BIO RAD LABORATORIES
Inventor： CURBELO RAUL
IPC: G01B9/02 , G01J3/447 , G01J3/45 , G01J3/453 , G01N21/17 , G01N21/19 , G01N21/21 , G01N21/27 , G01N21/35
Abstract: Digital signal processing (DSP) techniques for performing multiple modulation measurements with a polarization photoelastic modulator (PEM) in a step-scanning FT-IR spectrometer. The frequency and phase of the PEM drive signal are extracted from the digitized data collected for the actual measurement. This can then be used to perform the desired analysis of the polarization signals (e.g., CD, LD, DIRLD). This is accomplished by successively refining an initial estimate of the PEM frequency (typically starting at the nominal PEM frequency l 0 , or at the value determined from the previous step). This is done by using the current estimate of the PEM frequency to compute a phase error, and then using the computed phase error to refine the estimate of the PEM frequency. The phase errors are computed using different sets of samples in the sampling interval.
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公开(公告)号：DE19681406T1
公开(公告)日：1998-07-02
申请号：DE19681406
申请日：1996-05-06
Applicant: BIO RAD LABORATORIES
Inventor： CURBELO RAUL
Abstract: A laser beamsplitter for generating a plurality of parallel beams comprises a first beamsplitter and a second beamsplitter. The first and second beamsplitters are manufactured from glass flats having precisely parallel faces, wherein the front surface is coated with a reflective coating and the back surface is coated with a beamsplitter coating such that an initial laser beam passing through the first beamsplitter at a preferred angle of incidence is split into a first beam and a second beam. The second beamsplitter is positioned relative to the first beamsplitter such that the first beam passes through the second beamsplitter and is split into a third beam and a fourth beam. The parallelism of the output beams are determined by the parallelism of the glass flats, and no manual adjustments need to be made. The second, third, and fourth beams, if shone onto a surface orthogonal to the path of the initial beam, display three points that define a triangle, and preferably an equilateral triangle. The coatings on the surfaces of the first and second beamsplitters are chosen to provide three output beams having substantially the same intensity.
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公开(公告)号：GB2316766A
公开(公告)日：1998-03-04
申请号：GB9724020
申请日：1996-05-06
Applicant: BIO RAD LABORATORIES
Inventor： CURBELO RAUL
Abstract: A laser beamsplitter for generating a plurality of parallel beams (101, 102, 103) comprises a first beamsplitter (30) and a second beamsplitter (32). The first and second beamsplitters (30, 32) are manufactured from glass flats having precisely parallel faces, wherein the front surface (36) is coated with a reflective coating and the back surface (38) is coated with a beamsplitter coating such that an initial laser beam (99) passing through the first beamsplitter (30) at a preferred angle of incidence is split into a first beam (100) and a second beam (101). The second beamsplitter is positioned relative to the first beamsplitter such that the first beam (100) passes through the second beamsplitter and is split into a third beam (102) and a fourth beam (103).
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公开(公告)号：DE19654244A1
公开(公告)日：1997-07-17
申请号：DE19654244
申请日：1996-12-23
Applicant: BIO RAD LABORATORIES
Inventor： CURBELO RAUL
Abstract: By considering a transient signal as merely another signal in a linear, shift-invariant system representing a step-scanning Fourier transform spectrometer, the present invention characterizes the transient signal and then compensates for its effect on the measurement by employing various signal processing techniques. Thus, according to one aspect of the present invention, it provides a method for obtaining the spectrum of the desired signal by subtracting the Fourier transform of the transient signal from the Fourier transform of the composite signal output from the detector (i.e., the signal containing both the desired signal and the transient signal). According to another aspect of the present invention, it provides a method for deriving an estimate of the Fourier transform of the transient signal from the Fourier transform of the composite signal.
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Patent Agency Ranking26.发明专利
公开(公告)号：GB2328018B
公开(公告)日：2001-07-25
申请号：GB9817066
申请日：1998-08-05
Applicant: BIO RAD LABORATORIES
Inventor： CURBELO RAUL
Abstract: A technique for extracting the impulse response of a sample of interest includes corresponding measurements made with the sample of interest and a reference sample. At each of a series of steps in an FT-IR spectrometer, the sample of interest is illuminated with an excitation pulse of infrared radiation, acoustic signals having a time dependence oS(t) arising from the excitation pulse are captured, and a Fourier transform OS of oS(t) is computed. At each of a series of steps in the FT-IR spectrometer, the reference sample is illuminated with an excitation pulse of analytic radiation, acoustic signals having a time dependence OR(t) arising from the excitation pulse are captured, and a Fourier transform OR of oR(t) is computed. For each step, an inverse Fourier transform of the ratio OS/OR is computed to provide a series of values s(ti) for a series of times ti. These values s(ti) represent the impulse response s(t) of the sample of interest for the mix of optical frequencies for that retardation value. Interferograms are processed to provide photoacoustic spectra.
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公开(公告)号：DE69231585D1
公开(公告)日：2001-01-04
申请号：DE69231585
申请日：1992-05-08
Applicant: BIO RAD LABORATORIES
Inventor： CURBELO RAUL , JOHNSON B
Abstract: A fast and effective way to step a relative position quantity by a reference interval. Each step in relative position includes open-loop and closed-loop control intervals. An actuator (27) capable of changing the relative position and a closed loop servo (17) that acts on the actuator (27) to keep the relative position centered on the nearest of a series of reference values. The servo (17) has locked the relative position to a particular initial reference value. First, the actuator (27) is caused to change the relative position by an amount approximately equal to the reference interval in a manner that the servo (17) cannot track the change, such as by disabling the servo (17). Servo control is then re-established, at which point the servo (17) operates to keep the relative position centered on the nearest reference value.
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公开(公告)号：CA2122449A1
公开(公告)日：1993-05-27
申请号：CA2122449
申请日：1992-10-21
Applicant: BIO RAD LABORATORIES
Inventor： CURBELO RAUL
Abstract: 2122449 9310553 PCTABS00022 A technique that corrects photodetector non-linearity without increasing the noise level in the detector signal. The detector (10) is coupled to a preamplifier (100) characterized by the absence of positive feedback, and the preamplifier signal is communicated to a linear amplifier whose output signal is then digitized. The digitized signal is then transformed according to stored calibration information that is representative of the non-linear characteristic of the photodetector. The transformed digitized value thus exhibits a linear characteristic as a function of the intensity of the light source (180). A number of embodiments perform the correction in hardware before digitizing the signal.
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公开(公告)号：EP0595835A4
公开(公告)日：1995-02-01
申请号：EP92913202
申请日：1992-05-08
Applicant: BIO RAD LABORATORIES
Inventor： CURBELO RAUL , JOHNSON DAVID B
CPC classification number: G05B19/39 , G01J3/4535
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公开(公告)号：EP0613598A4
公开(公告)日：1994-07-19
申请号：EP92923250
申请日：1992-10-21
Applicant: BIO RAD LABORATORIES
Inventor： CURBELO RAUL
CPC classification number: G01N21/274 , G01J3/453 , G01J2001/086
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