Multichannel photometric measurement apparatus

• US 8,547,544 B2
• Filed: 07/20/2011
• Issued: 10/01/2013
• Est. Priority Date: 07/20/2010
• Status: Expired due to Fees

• Current Assignee: Yokogawa Electric Corporation
• Original Assignee: Yokogawa Electric Corporation
• Inventors: Horikoshi, Kumiko, Ichizawa, Yasushi, Kakuta, Shigeyuki, Nishida, Kazufumi
• Primary Examiner(s): NGUYEN, SANG H
• Application Number:
  US13/186,967
• Publication Number:
  US 20120019815A1
• Time in Patent Office: 804 Days
• Field of Search: 356213-217, 356 39- 41, 356/463, 356/317, 356/319, 356/326, 600/322, 600/323, 600/327, 250/494.1, 250/493.1
• US Class Current: 356/217
• CPC Class Codes: G01B 11/0691 of objects while moving G01B11/0616 takes precedence
• CPC Class Codes: G01N 2021/8663 Paper, e.g. gloss, moisture content
• CPC Class Codes: G01N 21/86 Investigating moving sheets G01N21/89 takes precedence

Abstract

A multichannel photometric measurement apparatus according to one embodiment includes: a single signal generator for generating an initial signal, the initial signal containing a harmonic component for collectively generating a plurality of modulation signals; a light emitting device including a plurality of light sources that are respectively drivable by each of the plurality of modulation signals having different frequencies; a light detector for detecting a plurality of kinds of light emitted from the light emitting device; and discriminating means for discriminating a detected signal output from the light detector per frequency domain of each of the different frequencies for each of the modulation signals.

Claims

1. A multichannel photometric measurement apparatus, comprising:

a single signal generator for generating an initial signal, the initial signal containing a harmonic component for collectively generating a plurality of modulation signals;

a light emitting device including a plurality of light sources that are respectively drivable by each of the plurality of modulation signals having different frequencies;

a light detector for detecting a plurality of kinds of light emitted from the light emitting device; and

discriminating means for discriminating a detected signal output from the light detector per frequency domain of each of the different frequencies for each of the modulation signals,

wherein the signal generator is included in the light emitting device,

wherein the light emitting device further includes a plurality of bandpass filters that extract a predetermined different frequency component from the initial signal generated by the signal generator, and

wherein the plurality of light sources is each drivable by a modulation signal having the frequency component extracted by a corresponding one of the bandpass filters.

2. The multichannel photometric measurement apparatus according to claim 1, wherein each of the plurality of bandpass filters has a cutoff characteristic to respectively extract the predetermined different frequency component from the initial signal generated by the signal generator.

3. A multichannel photometric measurement apparatus, comprising:

a single signal generator for generating an initial signal, the initial signal containing a harmonic component for collectively generating a plurality of modulation signals;

a light emitting device including a plurality of light sources that are respectively drivable by each of the plurality of modulation signals having different frequencies;

a light detector for detecting a plurality of kinds of light emitted from the light emitting device; and

discriminating means for discriminating a detected signal output from the light detector per frequency domain of each of the different frequencies for each of the modulation signals,

wherein the discriminating means includes an A/D converter that matches a width of a time window to load the detected signal with an integral multiple of an inverse of the frequency of the modulation signal to cause a plurality of frequency components contained in the detected signal input to the discriminating means to have an orthogonal relationship with each other.