Spectrophotometer for accurately measuring light intensity in a specific wavelength region

Claim 2

A spectrophotometer for measuring light intensity having an operator-adjustable sensitivity, said spectrophotometer comprising: a light splitting means for splitting the incident light into its different wavelengths; a plurality of light receiving means, one for each wavelength of light from said splitting means, for receiving the wavelengths of light and generating a light intensity spectral value for each wavelength of light received; a coefficient setting means for setting a plurality of sets of weighting coefficients, one coefficient for each wavelength of light received by said light receiving means; a selecting means for selecting at least one set of said plurality of sets of weighting coefficients; means for storing a first set of weighting coefficients based on an isochromatic function of a standard colorimetric system and a second set of weighting coefficients as selected by said selecting means; and a calculating means for multiplying each spectral light intensity value generated for each wavelength by said light receiving means times the respective weighting coefficient in said storing means, all said weighting coefficients being from said first set, or said second set, and summing all the products thereof for each wavelength.

Claim 3

A spectrophotometer as claimed in claim 1, wherein the calculating means includes means for calculating the sum of products relative to each of the sets of coefficients.

Claim 4

The spectrophotometer as claimed in claim 1, wherein said calculating means includes means for calculating a logarithmic value of the sum of products obtained.

Claim 5

A spectrophotometer as claimed in claim 1, further comprising a display means for displaying said coefficient values on a graph.

Claim 6

A spectrophotometer for measuring either a spectral reflectance or spectral transmittance of a test piece having an operator-adjustable sensitivity, said spectrophotometer comprising: a light source for irradiating said test piece; a splitting means for splitting incident light from the test piece into its different wavelengths; a plurality of light receiving means for receiving the wavelengths of light and generating light intensity spectral values for each wavelength of light received; a coefficient setting means for setting a plurality of sets of weighting coefficients, one coefficient for each wavelength of light received by said light receiving means; selecting means for selecting at least one set of weighting coefficients set by said coefficient setting means; means for storing a first set of weighting coefficients based on an isochromatic function of a standard colorimetric system and a second set as selected by said selecting means; and a calculating means for multiplying each spectral light intensity value generated for each wavelength by said light receiving means with the respective weighting coefficient in said storing means, all said weighting coefficients being from said first set or said second set and summing all the products for each wavelength.

Claim 7

A spectrophotometer for measuring either a spectral reflectance or spectral transmittance of a test piece having an operator-adjustable sensitivity, said spectrophotometer comprising: a light source for irradiating said test piece; a splitting means for splitting incident light from the test piece into its different wavelengths; a plurality of light receiving means for receiving the wavelengths of light and generating light intensity spectral values for each wavelength of light received; a coefficient setting means for setting a plurality of sets of weighting coefficients, one coefficient for each wavelength of light received by said light receiving means; selecting means for selecting at least one set of weighting coefficients set by said coefficient setting means; means for storing a first set of weighting coefficients based on an isochromatic function of a standard colorimetric system and a second set as selected by said selecting means; and a calculating means for multiplying each spectral light intensity value generated for each wavelength by said light receiving means with the respective weighting coefficient in said storing means, all said weighting coefficients being from said first set or said second set and summing all the products for each wavelength.

Claim 8

A spectrophotometer having a low-cost photoelectric conversion means for measuring the light intensity of each wavelength of light received from a test piece, said spectrophotometer comprising: a light source for irradiating the test piece; a first splitting means for splitting light coming from the test piece into its different wavelengths; a first array of light receiving elements for receiving the wavelengths of light from said first splitting means and generating a spectral light intensity for each light wave received; a second splitting means for splitting light emitted from said light source into its different wavelengths, wherein the pitch of the wavelengths of light from said second splitting means is larger than the pitch of the wavelength of light from said first splitting means; a second array of light receiving elements for receiving the wavelengths of light from said second splitting means and generating a spectral light intensity for each wavelength of light; an analog-to-digital converter for converting the spectral light intensity for each wavelength output from both the first and second light receiving element arrays into digital form; and a calculating means for calculating the ratios of the spectral light intensity outputs for each wavelength from the first light receiving element array to the spectral light intensity outputs for each wavelength from the second light receiving element array.

Claim 9

A spectrophotometer having a low-cost photoelectric conversion means for measuring the light intensity of each wavelength of light received from a test piece, said spectrophotometer comprising: a light source for irradiating the test piece; a first splitting means for splitting light coming from the test piece into its different wavelengths; a first array of light receiving elements for receiving the wavelengths of light from said first splitting means and generating a spectral light intensity for each light wave received; a second splitting means for splitting light emitted from said light source into its different wavelengths, wherein the pitch of the wavelengths of light from said second splitting means is larger than the pitch of the wavelength of light from said first splitting means; a second array of light receiving elements for receiving the wavelengths of light from said second splitting means and generating a spectral light intensity for each wavelength of light; an analog-to-digital converter for converting the spectral light intensity for each wavelength output from both the first and second light receiving element arrays into digital form; and a calculating means for calculating the ratios of the spectral light intensity outputs for each wavelength from the first light receiving element array to the spectral light intensity outputs for each wavelength from the second light receiving element array.

Claim 10

A spectrophotometer as claimed in claim 6, further comprising an interpolating means for calculating a value of light intensity for each wavelength from said first splitting means.

Claim 11

A spectrophotometer for accurately measuring light intensity Pi (where i=0, 1, 2 . . . n), by reducing the influence of neighboring wavelength regions, said spectrophotometer comprising: a light splitting means for splitting incident light into its different wavelengths; first detector means, having a first certain spectral sensitivity, a 11 , when detecting light in a first specific wavelength region, and a second certain spectral sensitivity, a 12 , when detecting light in a second neighboring specific wavelength region, for generating a first light value O 1 in response to receiving light from said splitting means; second detector means, having a certain spectral sensitivity, a 21 , when detecting light in said first specific wavelength region, and a second certain spectral sensitivity, a 22 , when detecting light in said second neighboring specific wavelength region, for generating a second light value O 2 in response to receiving light from said splitting means; means for storing the spectral sensitivities a 11 and a 12 of said first detector means; means for storing the spectral sensitivities a 21 and a 22 of said second detector means; and means for determining the accurately measured light intensity Pi (where i=1) in said first specific wavelength region, and the accurately measured light intensity Pi (where i=2) in said second specific wavelength region based on said first and second measured light values O 1 and O 2 and said stored spectral sensitivities a 11 , a 12 , a 21 , and a 22 , by solving the following equations for P 1 and P 2 : O.sub.1 =a.sub.11 P.sub.1 +a.sub.12 P.sub.2 O.sub.2 =a.sub.21 P.sub.1 +a.sub.22 P.sub.2.

Claim 12

A spectrophotometer for accurately measuring light intensity Pi (where i=0, 1, 2 . . . n), by reducing the influence of neighboring wavelength regions, said spectrophotometer comprising: a light splitting means for splitting incident light into its different wavelengths; first detector means, having a first certain spectral sensitivity, a 11 , when detecting light in a first specific wavelength region, and a second certain spectral sensitivity, a 12 , when detecting light in a second neighboring specific wavelength region, for generating a first light value O 1 in response to receiving light from said splitting means; second detector means, having a certain spectral sensitivity, a 21 , when detecting light in said first specific wavelength region, and a second certain spectral sensitivity, a 22 , when detecting light in said second neighboring specific wavelength region, for generating a second light value O 2 in response to receiving light from said splitting means; means for storing the spectral sensitivities a 11 and a 12 of said first detector means; means for storing the spectral sensitivities a 21 and a 22 of said second detector means; and means for determining the accurately measured light intensity Pi (where i=1) in said first specific wavelength region, and the accurately measured light intensity Pi (where i=2) in said second specific wavelength region based on said first and second measured light values O 1 and O 2 and said stored spectral sensitivities a 11 , a 12 , a 21 , and a 22 , by solving the following equations for P 1 and P 2 : O.sub.1 =a.sub.11 P.sub.1 +a.sub.12 P.sub.2 O.sub.2 =a.sub.21 P.sub.1 +a.sub.22 P.sub.2.

Claim 13

A spectrophotometer for accurately measuring light intensity by reducing the influence of wavelength overlap, said spectrophotometer comprising: a light splitting means for splitting incident light into its different wavelengths; a plurality of detecting means for detecting light from said splitting means and generating a light value therefore, each detecting means having a distinct spectral sensitivity for each specific wavelength region within its detection band; means for storing the distinct spectral sensitivities for each said detecting means; and means for determining the light intensity at each wavelength without the influence of wavelength overlap based on the light value generated by said detecting means and the spectral sensitivities stored by said storing means.

Claim 14

A spectrophotometer for accurately measuring light intensity by reducing the influence of wavelength overlap, said spectrophotometer comprising: a light splitting means for splitting incident light into its different wavelengths; a plurality of detecting means for detecting light from said splitting means and generating a light value therefore, each detecting means having a distinct spectral sensitivity for each specific wavelength region within its detection band; means for storing the distinct spectral sensitivities for each said detecting means; and means for determining the light intensity at each wavelength without the influence of wavelength overlap based on the light value generated by said detecting means and the spectral sensitivities stored by said storing means.

Claim 15

The spectrophotometer as claimed in claim 9, wherein said means for storing the distinct spectral sensitivities, stores said spectral sensitivities in a matrix format.

Claim 16

The spectrophotometer as claimed in claim 10 wherein said plurality of detecting means detect light intensities of each wavelength within a narrow band of wavelengths; and wherein said storing means stores said spectral sensitivities according to their respective wavelengths.

Claim 17

A spectrophotometer for accurately measuring light intensity by reducing the influence of wavelength overlap, said spectrophotometer comprising: a light splitting means for splitting incident light into its different wavelengths; a plurality of detector means for detecting light from said splitting means and generating light values in response thereto, each detector having a distinct spectral sensitivity for a predetermined band of wavelengths; means for storing each of said spectral sensitivities for each of said plurality of detector means in an inverse matrix derived from a normal matrix of spectral sensitivities wherein each component of the normal matrix represents a spectral sensitivity for a specific wavelength; and means for determining the light intensity at each specific wavelength by multiplying the stored inverse matrix of spectral sensitivities by the light values generated by said plurality of detector means.

Claim 18

A spectrophotometer for accurately measuring light intensity by reducing the influence of wavelength overlap, said spectrophotometer comprising: a light splitting means for splitting incident light into its different wavelengths; a plurality of detector means for detecting light from said splitting means and generating light values in response thereto, each detector having a distinct spectral sensitivity for a predetermined band of wavelengths; means for storing each of said spectral sensitivities for each of said plurality of detector means in an inverse matrix derived from a normal matrix of spectral sensitivities wherein each component of the normal matrix represents a spectral sensitivity for a specific wavelength; and means for determining the light intensity at each specific wavelength by multiplying the stored inverse matrix of spectral sensitivities by the light values generated by said plurality of detector means.

Claim 19

A spectrophotometer for accurately measuring light intensity pi (where i=0,1 . . . n) at n+1 different wavelengths by reducing wavelength overlap, said spectrophotometer comprising: a light splitting means for splitting incident light into its different wavelengths; a plurality of detecting means, each detecting means j (where j=0, 1, . . . k) detecting light from said splitting means and generating a light valve Oj (where j=0, 1, . . . k) therefore, each detecting means having a distinct spectral sensitivity aji (where j=0, 1 . . . k and i=0, 1 . . . n) for different wavelengths i (where i=0, 1, . . . n) respectively; memory means for storing the spectral sensitivities aji for said plurality of detecting means; and means for determining the light intensities pi at each wavelength i without wavelength overlap by using the detected light values Oj and the stored spectral sensitivities aji and solving the following equation for Pi: Oj=Aji Pi ##EQU15##

Claim 20

A spectrophotometer for accurately measuring light intensity pi (where i=0,1 . . . n) at n+1 different wavelengths by reducing wavelength overlap, said spectrophotometer comprising: a light splitting means for splitting incident light into its different wavelengths; a plurality of detecting means, each detecting means j (where j=0, 1, . . . k) detecting light from said splitting means and generating a light valve Oj (where j=0, 1, . . . k) therefore, each detecting means having a distinct spectral sensitivity aji (where j=0, 1 . . . k and i=0, 1 . . . n) for different wavelengths i (where i=0, 1, . . . n) respectively; memory means for storing the spectral sensitivities aji for said plurality of detecting means; and means for determining the light intensities pi at each wavelength i without wavelength overlap by using the detected light values Oj and the stored spectral sensitivities aji and solving the following equation for Pi: Oj=Aji Pi ##EQU15##

Claim 21

A spectrophotometer for accurately measuring light intensity pi (where i=0,1 . . . n) at n+1 different wavelengths, said spectrophotometer comprising: a light splitting means for splitting incident light into its different wavelengths; detecting means for detecting light from said splitting means and generating light values Oj (where j=0, 1 . . . k) therefore, said detecting means having different spectral sensitivities aji (where j=0, 1 . . . k and i=0, 1 . . . n) for different wavelengths i (where i=0, 1 . . . n); memory means for storing an inverse matrix aji -1 of a matrix Aji (where j=0, 1 . . . k and i=0, 1 . . . n) of said different spectral sensitivities aji, said matrix Aji being defined as follows: ##EQU16## means for determining the light intensity pi at each wavelength i by using the detected light values Oj and the stored inverse matrix Aji -1 and solving the following equation for Pi: Pi=Aji.sup.-1 Oj ##EQU17##

Claim 22

A spectrophotometer for accurately measuring light intensity pi (where i=0,1 . . . n) at n+1 different wavelengths, said spectrophotometer comprising: a light splitting means for splitting incident light into its different wavelengths; detecting means for detecting light from said splitting means and generating light values Oj (where j=0, 1 . . . k) therefore, said detecting means having different spectral sensitivities aji (where j=0, 1 . . . k and i=0, 1 . . . n) for different wavelengths i (where i=0, 1 . . . n); memory means for storing an inverse matrix aji -1 of a matrix Aji (where j=0, 1 . . . k and i=0, 1 . . . n) of said different spectral sensitivities aji, said matrix Aji being defined as follows: ##EQU16## means for determining the light intensity pi at each wavelength i by using the detected light values Oj and the stored inverse matrix Aji -1 and solving the following equation for Pi: Pi=Aji.sup.-1 Oj ##EQU17##

Claim 23

A spectrophotometer for measuring light intensity with the sensitivity freely set by a user, comprising: a light splitting means for splitting the incident light into its different wavelengths; a plurality of light receiving means, one for each wavelength of light from said splitting means, for receiving the wavelengths of light and generating a light intensity spectral value for each light wave received; a coefficient setting means for setting a plurality of sets of weighting coefficients, one coefficient for each wavelength of light received by said light receiving means; means for storing a first set of weighting coefficients based on an isochromatic function of a standard colorimetric system and second sets of weighting coefficients as set by the coefficient setting means; a selecting means for selecting at least one set of weighting coefficients from said first and second sets of weighting coefficients stored by the storing means; and a calculating means for multiplying each spectral light intensity value generated for each wavelength by said light receiving means times the respective weighting coefficient selected by the selecting means, and summing all the products thereof for each wavelength.

Claim 24

A spectrophotometer for measuring light intensity with the sensitivity freely set by a user, comprising: a light splitting means for splitting the incident light into its different wavelengths; a plurality of light receiving means, one for each wavelength of light from said splitting means, for receiving the wavelengths of light and generating a light intensity spectral value for each light wave received; a coefficient setting means for setting a plurality of sets of weighting coefficients, one coefficient for each wavelength of light received by said light receiving means; means for storing a first set of weighting coefficients based on an isochromatic function of a standard colorimetric system and second sets of weighting coefficients as set by the coefficient setting means; a selecting means for selecting at least one set of weighting coefficients from said first and second sets of weighting coefficients stored by the storing means; and a calculating means for multiplying each spectral light intensity value generated for each wavelength by said light receiving means times the respective weighting coefficient selected by the selecting means, and summing all the products thereof for each wavelength.