LED CLASSIFICATION METHOD, LED CLASSIFICATION DEVICE, RECORDING MEDIUM, AND LIQUID-CRYSTAL DISPLAY DEVICE
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Abstract
An LED classification device (21) classifies LEDs, the LEDs each including a combination of an LED element that emits a primary light and a phosphor that, upon excitation by the primary light, emits a secondary light having a longer wavelength than the primary light, the LEDs each emitting a combined light of the primary light and the secondary light, those ones of the LEDs whose primary lights having their chromaticities falling within a predetermined chromaticity range being classified as LEDs for use in a backlight of a liquid crystal display apparatus. A coefficient calculating section (26) and a corrected chromaticity calculating section (27) calculate, for all of the LEDs to be classified, correction values for the chromaticities as obtained on the assumption that the primary lights have traveled through a color filter of the liquid crystal display apparatus, and correct chromaticities by subtracting the correction values from chromaticities obtained for all of the LEDs to be classified, respectively. A chromaticity rank classification section (28) classifies the LEDs according to chromaticity rank on the basis of the corrected chromaticities.
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Citations
14 Claims
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1. (canceled)
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2. A method for classifying LEDs, the LEDs each including a combination of an LED element that emits a primary light and phosphor that, upon excitation by the primary light, emits a secondary light having a longer wavelength than the primary light, the LEDs each emitting a combined light of the primary light and the secondary light, those ones of the LEDs whose primary lights have their chromaticities falling within a predetermined chromaticity range being classified as LEDs for use in a backlight of a liquid crystal display apparatus,
the method comprising: -
a chromaticity predicting step of predicting, for all of the LEDs to be classified, the chromaticities of the primary lights having traveled through a color filter in a liquid crystal panel provided in the liquid crystal display apparatus; and a chromaticity rank classification step of classifying the LEDs according to chromaticity rank on a basis of the predicted chromaticities, the chromaticity predicting step includes a chromaticity correcting step of calculating, for all of the LEDs to be classified, correction values for the chromaticities as based on transmission of the primary lights through the color filter, and of correcting the chromaticities as corrected chromaticities on a basis of the correction values for all of the LEDs to be classified; and the chromaticity correcting step includes; a coefficient calculating step of calculating a reference chromaticity as of a time when a primary light having a predetermined reference wavelength has traveled through the color filter and amounts of change in the chromaticities with respect to the reference chromaticity, and of calculating, as coefficients of the correction values for the chromaticities, inclinations of the amounts of change with respect to a shift amount of each of the peak wavelengths of the primary lights from the reference wavelength, respectively; and a corrected chromaticity calculating step of calculating the correction values by multiplying a difference between the peak wavelength and the reference wavelength by the coefficients, respectively, and of calculating the corrected chromaticities by subtracting the correction values from the chromaticities obtained for all of the LEDs to be classified, respectively. - View Dependent Claims (3, 4, 5, 13, 14)
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6. (canceled)
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7. An LED classification device for classifying LEDs, the LEDs each including a combination of an LED element that emits a primary light and phosphor that, upon excitation by the primary light, emits a secondary light having a longer wavelength than the primary light, the LEDs each emitting a combined light of the primary light and the secondary light, those ones of the LEDs whose primary lights having their chromaticities falling within a predetermined chromaticity range being classified as LEDs for use in a backlight of a liquid crystal display apparatus,
the LED classification device comprising: -
a chromaticity predicting section for predicting, for all of the LEDs to be classified, the chromaticities of the primary lights having traveled through a color filter in a color filter provided the liquid crystal display apparatus; and a chromaticity rank classification section for classifying the LEDs according to chromaticity rank on a basis of the predicted chromaticities, the chromaticity predicting section includes a chromaticity correcting section for calculating, for all of the LEDs to be classified, correction values for the chromaticities as based on transmission of the primary lights through the color filter, and for correcting the chromaticities as corrected chromaticities on a basis of the correction values for all of the LEDs to be classified; and the chromaticity correcting section includes; a coefficient calculating section for calculating a reference chromaticity as of a time when a primary light having a predetermined reference wavelength has traveled through the color filter and amounts of change in the chromaticities with respect to the reference chromaticity, and for calculating, as coefficients of the correction values for the chromaticities, inclinations of the amounts of change with respect to a shift amount of each of the peak wavelengths of the primary lights from the reference wavelength, respectively; and a corrected chromaticity calculating section for calculating the correction values by multiplying a difference between the peak wavelength and the reference wavelength by the coefficients, respectively, and for calculating the corrected chromaticities by subtracting the correction values from the chromaticities obtained for all of the LEDs to be classified, respectively. - View Dependent Claims (8, 9, 10, 12)
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11. (canceled)
Specification