TWI392859B - A novel method and equipment for measuring chromaticity coordinate and intensity of light - Google Patents

Description

Device and method for chromaticity coordinates and brightness of measurable light

The present invention relates to the measurement of light, and more particularly to an apparatus and method for chromaticity coordinates and brightness of a measurable light.

When the light source of a certain color is seen by human beings, it is often only subjectively discriminating the color from the mouth, and the actual color quantity of the color cannot be directly read; thus the Commission Internationale de L'Eclairage (CIE) The average of the color perception of many normal visual people, the standard observer's color perception. In the CIE color matching experiment, the three primary colors are mixed to distribute the color of each single-wave light in the spectrum. The number of three primary colors used in the spectrum is called the spectral tristimulus value and is represented by R, G, and B; We do not directly use the tristimulus value to represent the color, but the relative proportion of the three primary colors in the total amount of R, G, and B. For example, when the relative luminance ratio of the three primary colors is 1.0000:4.5907:0.0601, Can match the equal energy white light, CIE selects the ratio as the unit quantity of the red, green and blue primary colors, so the relative proportion of the three primary colors in the total amount of R, G, B addition is the CIE chromaticity used to represent the color seen by the human eye. coordinate.

However, in order to know the CIE chromaticity coordinates and brightness of the visible light source color, it is often necessary to have a test environment as used in the CIE color matching experiment, generally using an integrating sphere to process the light source into a uniformly diffused beam output, and then cooperating with the spectrometer. The light source can be measured, but the price of the instruments is very expensive. In view of this, the inventor of the present invention is working to find the chromaticity coordinates and brightness of the measurable light, which can be lower than the aforementioned instruments. A much larger number of electronic components detect the visible light source of any human eye and calculate its CIE chromaticity coordinates and brightness.

The main object of the present invention is to provide a device and method for measuring the chromaticity coordinates and brightness of light, which can easily and quickly measure the CIE chromaticity coordinates and brightness of various human visible light sources, so as to solve the problem. A complex and expensive instrument can be used to measure the CIE chromaticity coordinates and brightness of a light source color.

In order to achieve the above object, a device for measuring the chromaticity coordinates and brightness of the light according to the technical idea of the present invention includes at least one photodetector, a multiplexer, an analog-to-digital converter, and an arithmetic processing. And a display. The photodetector is configured to detect a light source and output a plurality of electrical signals corresponding to different wavelength ranges of the light source; the multiplexer is configured to receive the electrical signal output by the optical detector, and the different telecommunication signals Selectively switching the output; the analog-to-digital converter is electrically connected to the multiplexer to receive the electrical signal output by the multiplexer, convert it into a digital signal, and output the same; The device and the analog digital converter are electrically connected to control the multiplexer to switch to receive different electrical signals output by the optical detector, and receive the digital signal output by the analog digital converter, and convert the digital signals into CIE The chromaticity coordinate and the brightness value are re-outputted; the display is electrically connected to the arithmetic processor to display the value calculated by the processor; by the above technical means, the measurement is performed without using a complicated and expensive instrument, that is, The CIE chromaticity coordinates and brightness of any source can be measured easily and quickly.

The device for chromaticity coordinates and brightness of the above-mentioned measurable light may have a three-photodetector, and the photodetectors may be made of a photodiode for detecting the light source, and The electrical signals corresponding to the red, green and blue light levels of the light source are respectively output; the optical diodes have low energy consumption, high power, small volume, and rapid response, which can improve the functionality and convenience of the measuring device.

In the above apparatus for measuring the chromaticity coordinates and brightness of the light, the arithmetic processor may be a programmable single chip storing a parameter matrix for converting the RGB color system into one of the XYZ color systems, thereby Make the measuring device more concise and convenient. Moreover, the photodetector can output different voltage signals corresponding to different wavelength ranges of the light source, and the programmable single chip can store a conversion mode for converting voltage signals corresponding to different wavelengths into an RGB color system.

Another apparatus for measuring the chromaticity coordinates and brightness of the light according to the technical idea of the present invention comprises at least one photodetector, a programmable single chip, and a display; the photodetector system Detecting a light source and outputting a plurality of electrical signals corresponding to different wavelength ranges of the light source; the programmable single chip includes a multiplex processing program, an analog-to-digital conversion program, and an operation processing program, the single The chip is configured to receive the electrical signals output by the optical detector, and sequentially process the electrical signals by using the programs, and the multiplexing processing program is configured to output different telecommunication signals to the optical detector. Selective switching output, the analog converting program is used to convert the electrical signal outputted by the multiplex processing program into a digital signal, and the arithmetic processing program is used for outputting the digital signal of the analog digital conversion program. Computing the CIE chromaticity coordinates and the brightness value and outputting the same; the display is electrically connected to the programmable single chip to display the value calculated by the operation processing program; The above techniques can also be used without the complicated and expensive measuring instrument, i.e., easy and quickly measured as CIE chromaticity coordinates and luminance of a light source.

The device for chromaticity coordinates and brightness of the above-mentioned measurable light may have three photodetectors, and the photodetectors may be made of photodiodes for detecting the light source and respectively outputting pairs The electrical signal of the red, green and blue light of the light source should be used; thereby, the functionality and convenience of the measuring device can be improved.

According to the technical idea of the present invention, a method for measuring the chromaticity coordinates and brightness of a light is to first drive a light source with a rated current, and then use a spectrometer and an integrating sphere to measure the red, green and blue light of the light source. The spectrum of the wavelength range, which in turn obtains the first stimulus values R ₀ , G ₀ , B _{0 of} the light source in the RGB color system, and then passes the CIE 1931 2-deg XYZ Color Matching Functions. Adding the stimulus values of each of the spectra in the XYZ color system to obtain the second stimulus values X ₀ , Y ₀ and Z _{0 of} the light source in the XYZ color system, and R ₀ , G ₀ , B ₀ , X ₀ , Y ₀ and Z ₀ are substituted into the following parameters of R, G, B, X, Y and Z of the first equation:

Get the following parameter matrix:

The parameter matrix is used to convert the stimulus value of any source containing the three primary colors in the RGB color system to the stimulus value of the XYZ color system; and use at least one photodetector to measure the red color corresponding to a light source to be tested. , green, blue light brightness voltages V _r , V _g , V _b , and then use the following two equations for converting the red, green, blue light intensity corresponding voltage of the light source to be tested and the RGB color system stimulus value:

Substituting V _r , V _g , V _b into the parameters of V _R , V _G , V _B and the like of the second equation to obtain a first chromaticity coordinate of the light source to be tested in the RGB color system (R _t , G _t , B _t ) is the brightness of the red, green and blue light of the light source to be tested; using a third-party program:

Calculating the second chromaticity coordinate (X _t , Y _t , Z _t ) of the light source to be tested in the XYZ color system; using a fourth equation And a fifth equation Converting a quadratic chromaticity coordinate (x, y) of the light source to be tested.

Detailed construction, features, assembly or use of the apparatus and method for chromaticity coordinates and brightness of the measurable light provided by the present invention will be described in the detailed description of the subsequent embodiments. However, it should be understood by those of ordinary skill in the art that the present invention is not limited by the scope of the invention.

The technical content and features of the present invention will be described in detail below with reference to the accompanying drawings, wherein the first figure is the color of the measurable light provided by the first preferred embodiment of the present invention. A block diagram of a device for measuring coordinates and brightness; a second block diagram showing steps of a method for measuring the chromaticity coordinates and brightness of the measurable light according to the first preferred embodiment of the present invention; A block diagram of a device for measuring the chromaticity coordinates and brightness of the measurable light provided by the second preferred embodiment; the fourth figure is a chromaticity coordinate of the measurable light provided by a third preferred embodiment of the present invention A block diagram of a device for brightness; and a fifth block diagram of a programmable single chip for a device for chromaticity coordinates and brightness of the measurable light provided by the third preferred embodiment of the present invention.

As shown in the first figure, a device 10 for chromaticity coordinates and brightness of a measurable light according to a first preferred embodiment of the present invention includes a photoelectric conversion circuit 20, a processing unit 30, and a liquid crystal display 40. .

The photoelectric conversion circuit 20 has a function of detecting a light source and outputting a photoelectric signal corresponding to brightness of different wavelengths included in the light source. The photoelectric conversion circuit 20 includes a three-light detecting diode 22, a three-low-pass filter 24, and three first amplifiers 26; each of the light detecting diodes 22 is configured to detect that a light source device 50 emits The light visible to the human eye, according to the received optical signals of different wavelengths, respectively detects the brightness of red, green and blue light, and converts them into electrical signals such as photocurrent or photovoltage corresponding to the brightness, and outputs them to the respective signals. Each of the low-pass filters 24 is electrically connected to each of the photodetecting diodes 22 and the first amplifiers 26, and each of the low-passing filters 24 respectively receives the photodetecting diodes After outputting each of the electrical signals, the body 22 filters out high frequency noise from the ambient noise of the circuit to obtain a relatively stable electrical signal, and then outputs the electrical signal to the first amplifier 26; the first amplifier 26 is electrically The processing unit 30 is connected to each of the first amplifiers 26 to receive the electrical signals output by the low-pass filters 24, and then amplified and output to the processing unit 30. Of course, the filters 24 are not necessary for the present invention. If the circuit design has high-quality environmental noise isolation devices, the elimination of the filters 24 can reduce the power attenuation caused by the filtering, and can also be omitted. The circuit space occupied by the filter component and the amplification power of the amplifier required by the signal in the subsequent stage of the circuit can not only reduce the circuit volume but also reduce the circuit cost, and can still achieve the effect desired by the invention.

The processing unit 30 includes a multiplexer 32, a second amplifier 34, an analog-to-digital converter 36, and an arithmetic processor 38. The processing unit 30 receives the electrical signals output by the first amplifiers 26. The multiplexer 32 is selectively switched to turn on the photodetecting diodes 22 to switch the respective electrical signals to the second amplifier 34; the second amplifier 34 receives the multiplexer The output electrical signal of 32 is amplified and increased in resolution, and then output to the analog-to-digital converter 36. The analog-to-digital converter 36 receives the electrical signal output by the second amplifier 34 and converts it into a digital position. After the signal, the signal is output to the operation processor 38. The operation processor 38 has a programmable single chip, and the digital signal output from the analog-to-digital converter 36 can be calculated by writing and storing the internal program. The CIE chromaticity coordinates and brightness of the light emitted by the light source device 50.

The liquid crystal display 40 is electrically connected to the processing unit 30 for receiving and processing the signal output by the arithmetic processor 38, and displaying the CIE chromaticity coordinates and brightness of the light emitted by the light source device 50.

The above is the apparatus 10 for chromaticity coordinates and brightness of the measurable light provided in the embodiment, wherein the arithmetic processing program written in the arithmetic processor 38 is used to measure the chromaticity coordinates and brightness of the light. An important part of the method; please refer to the second figure, the method obtained by the formula used by the arithmetic processing program, and the method using the formula, with an example as follows: driving a three primary color light emitting diode with a current of 20 mA a light source of the RGB LED, and using a spectrometer and an integrating sphere to measure the spectrum of the red, green and blue wavelength ranges of the light source, thereby obtaining the first stimulation value R ₀ , G of the light source in the RGB color system. ₀ , B ₀ ; and then through the CIE 1931 2-deg XYZ Color Matching Functions, the stimulus values of each of the spectra in the XYZ color system are added to obtain the light source in the XYZ color system. Third stimuli values X ₀ , Y ₀ and Z ₀ ; R ₀ , G ₀ , B ₀ , X ₀ , Y ₀ and Z ₀ are substituted into R, G, B, X, Y of the following first equation, respectively. And Z and other parameters: Obtain a parameter matrix that is converted to an XYZ color system using the RGB color system Therefore, the parameter matrix can be used to convert the stimulus value of any RGB LED light source in the RGB color system to the stimulus value of the XYZ color system; further, the following second equation: The stimuli value of any RGB LED light source in the RGB color system and the corresponding voltage signal generated by the photodiode for detecting red, green, and blue light brightness, and the conversion between the two; The device 10 for chromaticity coordinates and brightness detects the light emitted by the light source device 50, and measures the voltage values V _r , V _g , V _b corresponding to the red, blue and green lights respectively, and the processing unit The analog-to-digital converter 36 converts the voltage values into digital signals, and inputs them to the arithmetic processor 38, which uses the second equation to substitute the voltage values V _r , V _g , and V _b into the first The voltage parameters V _R , V _G , V _{B of the} second equation can be used to calculate the three luminance values R _t , G _t and B _{t of the} red, blue and green light respectively emitted by the light source device 50 . The following third-party program is additionally utilized in the arithmetic processor 38: And using the parameter matrix obtained as described above, converting the brightness values R _t , G _t and B _t calculated by the second equation into corresponding three XYZ color system stimulation values X _t , Y _t and Z _t It can also be expressed as a chromaticity coordinate (X _t , Y _t , Z _t ) of the light emitted by the light source device 50 in the XYZ color system; and the following fourth equation is also used in the operation processor 38: And the following fifth equation: Converting the three stimulus values X _t , Y _t and Z _t calculated by the third-party program into corresponding two values x and y, which may also be expressed as a quadratic chromaticity coordinate of the light emitted by the light source device 50 (x, y).

Thereby, the arithmetic processor 38 of the chromaticity coordinate and brightness device 10 of the measurable light outputs the light values emitted by the light source device 50, respectively representing the brightness values R of red, blue and green light. _t , G _t and B _t , and the signals corresponding to the values x, y representing the CIE chromaticity coordinates, after the liquid crystal display 40 receives, the values are displayed.

It is to be noted that, in this embodiment, the photoelectric conversion circuit 20 uses three light detecting diodes 22 to detect the light emitted by the light source device 50, and outputs corresponding red, green, and The function of the signal of the blue light brightness, however, the manner in which the function is actually achieved is not limited thereto, and the method of the second preferred embodiment described below may be used.

As shown in the third figure, the difference between the chromaticity coordinate and luminance device 60 of the measurable light provided by the second preferred embodiment of the present invention and the device 10 provided in the first preferred embodiment is different. Only part of the photoelectric conversion circuit, the rest is the same as the device 10. The photoelectric conversion circuit 70 of the present embodiment includes a photodetector 72 having a detection range covering red, green, and blue wavelengths, and a three-pass filter 74 for processing respective wavelengths of light as provided in the above embodiment. And three first amplifiers 76.

The photodetector 72 is configured to detect the light emitted by the light source device 50 and visible to the human eye, and convert the received optical signals of different wavelengths into voltage signals, and output the signals to the low pass filters 74. And each of the first amplifiers 76.

Therefore, the photoelectric conversion circuit 70 of the embodiment can also detect the light emitted by the light source device 50, and switch the output by multiplexing processing by the processing unit 30 as described in the first preferred embodiment. Corresponding to the electrical signals of the red, green and blue light luminances, the processing unit 30 performs amplification processing, digital analog conversion and arithmetic processing, and finally is calculated by the liquid crystal display 40 as described in the first preferred embodiment. Numerical display When it comes out, the function of measuring the chromaticity coordinates and brightness of the light emitted by the light source device 50 can be achieved.

Furthermore, in the first preferred embodiment, the processing unit 30 is configured to input the multiplexer 32, the second amplifier 34, the analog-to-digital converter 36, and the arithmetic processor 38. The signal is multiplexed, amplified, and digitally analogized, and performs the function of the operation. However, the manner in which the function is actually implemented is not limited thereto, and one of the following preferred embodiments may be used. The way to use it.

As shown in the fourth figure, the difference between the chromaticity coordinate and brightness device 80 of the measurable light provided by the third preferred embodiment of the present invention and the device 10 provided in the first preferred embodiment is different. Only part of the processing unit, the rest is the same as the device 10. The processing unit of the embodiment is a programmable single chip 90, and a multiplex processing program, an amplifying program, an analog-to-digital conversion program, and an arithmetic processing program can be written and stored, and the multiplex processing is sequentially performed. , the amplification processing, the analog digital conversion processing, and the processing steps are as shown in the fifth figure; that is, the functions of the programs are respectively corresponding to the multiplex processor 32 and the second amplifier in the first embodiment. 34. The analog digital converter 36, and the arithmetic processor 38 are identical.

Therefore, the programmable single chip 90 of the embodiment can also receive the signal outputted by the photoelectric conversion circuit 20, 70 as described in the first or second preferred embodiment, and perform multiplexing. The functions of the amplification processing, the digital analog conversion, and the arithmetic processing are finally displayed by the liquid crystal display 40 as described in the first preferred embodiment, so that the light source device 50 can be measured. The function of the chromaticity coordinates and brightness of the light.

Finally, it is to be noted that the constituent elements disclosed in the foregoing embodiments are merely illustrative and are not intended to limit the scope of the present invention, and alternative or variations of other equivalent elements should also be the scope of the patent application of the present application. Covered.

[First preferred embodiment]

10. . . Device for measuring the chromaticity coordinates and brightness of light

20. . . Photoelectric conversion circuit

twenty two. . . Light detection diode

twenty four. . . Low pass filter

26. . . First amplifier

30. . . Processing unit

32. . . Multiplex processor

34. . . Second amplifier

36. . . Analog digital converter

38. . . Arithmetic processor

40. . . LCD Monitor

50. . . Light source device

[Second preferred embodiment]

50. . . Light source device

60. . . Device for measuring the chromaticity coordinates and brightness of light

70. . . Photoelectric conversion circuit

72. . . Light detector

74. . . Low pass filter

76. . . First amplifier

[Third preferred embodiment]

50. . . Light source device

80. . . Device for measuring the chromaticity coordinates and brightness of light

90. . . Programmable single chip

1 is a block diagram of a device for measuring the chromaticity coordinates and brightness of a measurable light according to a first preferred embodiment of the present invention;

2 is a block diagram showing the steps of a method for measuring the chromaticity coordinates and brightness of the measurable light according to the first preferred embodiment of the present invention;

3 is a block diagram of a device for measuring the chromaticity coordinates and brightness of a measurable light according to a second preferred embodiment of the present invention;

4 is a block diagram of a device for chromaticity coordinates and brightness of a measurable light meter according to a third preferred embodiment of the present invention;

Figure 5 is a block diagram showing the steps of a programmable single chip of a device for measuring the chromaticity coordinates and brightness of the measurable light according to the third preferred embodiment of the present invention.

10. . . Device for measuring the chromaticity coordinates and brightness of light

20. . . Photoelectric conversion circuit

twenty two. . . Light detection diode

twenty four. . . Low pass filter

26. . . First amplifier

30. . . Processing unit

32. . . Multiplex processor

34. . . Second amplifier

36. . . Analog digital converter

38. . . Arithmetic processor

40. . . LCD Monitor

50. . . Light source device

Claims (7)

A device for measuring the chromaticity coordinate and brightness of the light for measuring the chromaticity coordinates of the visible light source of the human eye, the device comprising: at least one light detector for detecting the light source and outputting the majority a multiplexer corresponding to a different wavelength range of the light source; a multiplexer for receiving the electrical signal output by the photodetector, selectively switching the different electrical signals; and an analog-to-digital converter and the multiplexer The device is electrically connected to receive the electrical signal outputted by the multiplexer, and is converted into a digital signal and then output; an arithmetic processor is electrically connected to the multiplexer and the analog digital converter to control the multi-processor The device switches to receive different electrical signals output by the optical detector, and receives the digital signals output by the analog digital converter, converts the digital signals into CIE chromaticity coordinates and brightness values, and outputs the same; Electrically coupled to the operational processor to display values computed by the processor. The device for chromaticity coordinates and brightness of the measurable light meter as described in claim 1 has a three-light detector, which is made of a photodiode for detecting The light source outputs the electrical signals corresponding to the red, green and blue light levels of the light source. The apparatus for chromaticity coordinates and brightness of the measurable light as described in claim 1 or 2, wherein the arithmetic processor is a programmable single chip, and the programmable single chip stores the RGB table. The color system is converted to a parameter matrix of one of the XYZ color systems. The apparatus for chromaticity coordinates and brightness of the measurable light as described in claim 3, wherein the photodetector outputs different voltage signals corresponding to different wavelength ranges of the light source, and the programmable single chip is stored The voltage signals corresponding to different wavelengths are converted into one conversion mode of the RGB color system. A device for measuring the chromaticity coordinate and brightness of the light for measuring the chromaticity coordinates of the visible light source of the human eye, the device comprising: at least one light detector for detecting the light source and outputting the majority a signal signal corresponding to different wavelength ranges of the light source; a programmable single chip containing a plurality of programs for receiving the electrical signals output by the optical detector, and sequentially The electronic signals are processed in a sequence of: a multiplex processing program for selectively switching the output of the different electrical signals output by the optical detector; and an analog-to-digital conversion program for The electrical signal outputted by the processing program is converted into a digital signal and then output; and an arithmetic processing program is used to output the digital signal outputted by the analog-to-digital conversion program, and calculate the CIE chromaticity coordinate and the brightness value and output; A display is electrically connected to the programmable single chip to display the value calculated by the operation processing program. The device for chromaticity coordinates and brightness of the measurable light meter described in claim 5 has a three-light detector, and the photodetectors are made of optical diodes for inspection. Know the light source and output the electrical signals corresponding to the red, green and blue light levels of the light source. A method for measurable chromaticity coordinates and brightness, comprising the steps of: a) providing a light source covering a range of wavelengths of three primary colors of red, green and blue; b) measuring a red color using a spectrometer and an integrating sphere, respectively The spectrum of the wavelength range of the green and blue light, and then obtain the first stimulus values R ₀ , G ₀ , B _{0 of} the light source in the RGB color system; c) pass the CIE 1931 second-degree angular color matching function, and the respective spectra are The stimulus values of the XYZ color system are added to obtain the second stimulus values X ₀ , Y ₀ and Z _{0 of} the light source in the XYZ color system; d) the first stimulus values R ₀ , G _{0 of} the light source And B ₀ , and the second stimulation values X ₀ , Y ₀ and Z ₀ are respectively substituted into parameters of R, G, B, X, Y and Z of the following first equation: Get the following parameter matrix: The parameter matrix is used to convert the stimulus value of any light source containing the three primary colors in the RGB color system to the stimulus value of the XYZ color system; e) use at least one photodetector to measure the corresponding one to be tested. The first voltage V _r , the second voltage V _g , and the third voltage V _b of the red, green, and blue light luminances; f) using the following red, green, and blue light luminance corresponding to the light source to be tested and the RGB color One of the system stimulus values, the second equation: Substituting the voltages V _r , V _g , V _b measured in the step e) into the parameters of V _R , V _G , V _B and the like of the second equation to obtain the light source to be tested in the RGB color system A chromaticity coordinate (R _t , G _t , B _t ) is the brightness of the red, green and blue light of the light source to be tested; g) using a third-party program: Calculating the second chromaticity coordinate (X _t , Y _t , Z _t ) of the light source to be tested in the XYZ color system; h) using a fourth equation: And a fifth equation: The quadratic chromaticity coordinate (x, y) of one of the light sources to be tested is converted.