JP2006071589A - Color measuring instrument and light source device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a color measuring instrument and a light source device, both reduced in size. <P>SOLUTION: A plurality of white color LEDs 21, 22, 23, and color filters 24, 25, 26 respectively emit lights different in wavelengths; an irradiating light guide member 203 guides to a testing paper face a mixed beam mixed with the lights emitted from the plurality of white color LEDs 21, 22, 23, and color filters 24, 25, 26; a photoelectric transfer part 27 receives a reflected beam reflected by the test paper face, and converts the received reflected beam into a light intensity signal; and a color measuring part 3 resolves the light intensity signal converted by the photoelectric transfer part 27 in every of the plurality of wavelengths of the light source, and measures a color of test paper, on the basis of resolved light intensity signals. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a color measuring device that measures the color of a measurement object and a light source device that irradiates light to the measurement object and receives light reflected by the measurement object by a light receiving unit.

  Conventionally, in a biochemical test, negative or positive is determined by immersing a test paper in urine, blood, saliva, and the like and measuring the coloration (see, for example, Patent Document 1). When such an inspection is performed on a daily basis, the user determines the inspection result by visual comparison between the colored test paper and a sample color tone table. Therefore, the accuracy of the inspection result was low.

In urinalysis in medical institutions, a urinalysis apparatus that reads a test paper with high accuracy and automatically obtains and displays urinalysis items from the color change is used. In this urinalysis apparatus, 45 degree irradiation-vertical light reception type reflected light measurement is used as a color measurement method, and four single wavelength LEDs (red: 635 nm, green: 585 nm, blue: 565 nm, near infrared: 760) are used. It is used.
JP 2001-141644 A

  However, since the conventional urinalysis apparatus uses an optical system such as a spectroscope, the apparatus is increased in size and cost. Moreover, it cannot be said that it is excellent in portability for daily use by a home user. Further, when the single wavelength light source has a steep spectral distribution, there is a risk that the color measurement accuracy of an intermediate color whose spectral distribution is unknown will deteriorate.

  SUMMARY An advantage of some aspects of the invention is to provide a color measuring device and a light source device that can be miniaturized.

  The color measurement device according to the present invention is a color measurement device that measures the color of a measurement object, and is a mixture in which a plurality of light sources that irradiate light of different wavelengths and light emitted by the plurality of light sources are mixed. Light guide means for guiding light to the measurement object, photoelectric conversion means for receiving the reflected light reflected by the measurement object, and converting the received reflected light into a light intensity signal, and conversion by the photoelectric conversion means And a color measuring unit that decomposes the light intensity signal for each wavelength of the plurality of light sources and measures the color of the measurement object based on the decomposed light intensity signal.

  According to this configuration, light having different wavelengths is irradiated by the plurality of light sources, and mixed light obtained by mixing the light irradiated by the plurality of light sources is guided to the measurement object by the light guide unit. The reflected light reflected by the measurement object is received by the photoelectric conversion means, and the received reflected light is converted into a light intensity signal. The color measurement means decomposes the light intensity signal converted by the photoelectric conversion means for each wavelength of the plurality of light sources, and measures the color of the measurement object based on the decomposed light intensity signals.

  Therefore, the light intensity signal is decomposed for each wavelength of the plurality of light sources, and the color of the measurement object is measured based on the decomposed light intensity signal. Therefore, the light of the plurality of wavelengths is mixed without using an optical component. The mixed light can be decomposed and downsizing can be realized.

  The color measuring device further includes lighting control means for pulse-lighting the light sources at different lighting frequencies, and the color measuring means has a plurality of bandpass filters having the lighting frequency as a center frequency. And it is preferable to extract the light intensity signal corresponding to the light of the wavelength of each light source from the light intensity signal converted by the photoelectric conversion means using each band pass filter.

  According to this configuration, a plurality of light sources are pulse-lit at different lighting frequencies, and light having a wavelength of each light source is converted from a light intensity signal converted by the photoelectric conversion means by a plurality of bandpass filters having the lighting frequency as a center frequency. Since the light intensity signal corresponding to is extracted, light of a plurality of wavelengths can be decomposed by an electric circuit, not by an optical component that enlarges the apparatus.

  In the color measuring apparatus, it is preferable that the lighting control unit pulse-lights each light source at a relatively low lighting frequency. According to this configuration, since the lighting frequencies of the plurality of light sources are turned on so that they are relatively prime, the light intensity signal can be reliably decomposed without overlapping the lighting frequencies of the plurality of light sources.

  Further, in the color measurement apparatus, the measurement object includes a test paper whose coloration state changes with respect to a predetermined inspection item, and the color measurement unit calculates a hue value of the test paper and calculates It is preferable to calculate the inspection item value corresponding to the coloration state based on the hue value.

  According to this configuration, the hue value of the test paper whose coloration state changes with respect to the predetermined inspection item is calculated by the color measuring unit, and the inspection item value corresponding to the inspection item is calculated based on the calculated hue value. Since it is calculated, it is possible to quantitatively measure the inspection item value instead of the stepwise visual measurement as in the prior art. In addition, the inspection can be performed with higher accuracy than the conventional visual inspection.

  Further, in the color measurement apparatus, the light source transmits only light having a wavelength corresponding to any one color component of red, green, and blue from white LED and light emitted by the white LED. It is preferable to have a color filter.

  According to this configuration, the light source transmits only light having a wavelength corresponding to any one color component of red, green, and blue from the light emitted from the white LED (light emitting diode) and the white LED. A color filter to be used. Therefore, complicated maintenance can be made unnecessary by using a white LED having excellent versatility.

  In the color measuring apparatus, the color filter preferably has a characteristic that the transmittance distribution changes gradually with respect to the wavelength. According to this configuration, since the transmittance distribution of the color filter has a characteristic that changes gradually with respect to the wavelength, it is possible to improve the color measurement accuracy of not only red, green and blue but also their intermediate colors. it can.

  A light source device according to the present invention is a light source device that irradiates light to a measurement object and receives light reflected by the measurement object by a light receiving unit, and a plurality of light sources that respectively irradiate light of different wavelengths, A light receiving light guide member that guides reflected light reflected by the measurement object to the light receiving unit, and a reflection that is provided outside the light receiving light guide member and reflects the light emitted by the plurality of light sources. A light guide member for irradiation that is provided outside the reflection member and that mixes light from a plurality of light sources incident from the outer peripheral surface thereof and guides the light to a measurement object; the plurality of light sources; and An external light blocking material that covers the irradiation light guide member and blocks external light.

  According to this configuration, the light from the plurality of light sources incident from the outer peripheral surface is mixed and guided to the measurement object by the light guide member for irradiation, and the light sources and the light are irradiated by the external light blocking material. The light guide member is covered and external light is blocked, and the light irradiated by the plurality of light sources is reflected by the reflective member provided along the inner peripheral surface of the light guide member for irradiation. Reflected light reflected by the measurement object is guided to the light receiving unit by the light receiving light guide member provided on the inner peripheral surface side.

  Therefore, light with different wavelengths emitted from multiple light sources can be mixed without using an optical system, and it can be made more compact than when mixing light using a special optical system. can do.

  Further, in the above light source device, the end portion of the irradiation light guide member on which light is incident on the measurement object is formed in a curved surface shape so that regular reflection light from the measurement object is not incident on the light reception light guide member It is preferred that According to this configuration, since the regular reflection light of the light emitted from the light source does not enter the light receiving light guide member, the photoelectric conversion means receives only the reflected light of the measurement object and maintains a good measurement accuracy. be able to.

  According to the present invention, the light intensity signal is decomposed for each wavelength of the plurality of light sources, and the color of the measurement object is measured based on the decomposed light intensity signal. The mixed light obtained by mixing light can be decomposed, and downsizing can be realized.

  Hereinafter, a color measuring apparatus according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a diagram showing a configuration of a color measuring apparatus according to the present invention. A color measuring device 1 shown in FIG. 1 includes a pen-type probe unit 2 and a color measuring unit 3.

  The probe unit 2 includes a plurality of white LEDs (light emitting diodes) 21, 22, 23, a plurality of color filters 24, 25, 26, a photoelectric conversion unit 27, an I / V conversion unit 28, a pulse lighting control unit 29, and an outer edge member 201. , An external light blocking member 202, an irradiation light guide member 203, an irradiation light reflecting member 204, and a light receiving light guide member 205.

  The white LEDs 21, 22, and 23 emit white light. As the white LEDs 21, 22, and 23, for example, BSPW500BS manufactured by Nichia Corporation is used.

  The color filters 24, 25, and 26 transmit only light having a specific wavelength from the light emitted from the white LEDs 21, 22, and 23. In the present embodiment, since the light emitted from the white LEDs 21, 22, 23 is separated into three colors of R (red), G (green), and B (blue), the color filter 24 is a red color glass filter (for example, R25A manufactured by Kenko Corporation), a color glass filter 25 using a green color glass filter (for example, G-530 manufactured by Kenko Corporation), and a color filter 26 using a blue color glass filter (for example, B-440 manufactured by Kenko Corporation). Is used. Conventional devices often use multiple single-wavelength LEDs, but each spectral distribution is a narrow band, so multiple wavelength regions with almost no irradiation light intensity are generated, and color measurement corresponding to those regions occurs. There is a risk that the accuracy is significantly deteriorated. However, as in this embodiment, only light of a specific wavelength is transmitted by transmitting light emitted from the white LED through the color filter, so that the intensity of irradiation light is ensured in any wavelength region. Thus, good color measurement is possible.

  As the color filters 24, 25, and 26, gelatin filters may be used. In this case, for example, the color filter 24 uses a red gelatin glass filter of SC-60 manufactured by Fuji Photo Film, the color filter 25 uses a green gelatin filter of BPB-53 manufactured by Fuji Photo Film, and the color filter 26 uses A BPB-45 blue gelatin filter manufactured by Fuji Photo Film Co., Ltd. is used. In this way, when a colored glass filter or gelatin filter is used, there is almost no change in the transmitted light distribution due to the change in the incident angle. This can be prevented, and is effective in terms of manufacturing and maintenance.

FIG. 2 is a diagram schematically showing the characteristics of the transmittance distribution of each color filter. Note that the vertical axis in FIG. 2 represents transmittance (%), and the horizontal axis represents wavelength λ (nm). T _R shown in FIG. 2 represents the transmitted light distribution of the color filter 24 that transmits the wavelength of the red component, _TG represents the transmitted light distribution of the color filter 25 that transmits the wavelength of the green component, and T _B represents The transmitted light distribution of the color filter 26 that transmits the wavelength of the blue component is shown. As shown in FIG. 2, the color filters 24, 25, and 26 have a characteristic that the transmittance distribution changes gently with respect to the wavelength. Therefore, instead of using a filter that shows a steep rise only at a specific wavelength, a color filter having a characteristic that the transmittance distribution changes gently with respect to the wavelength is used. In addition, the color measurement accuracy of those intermediate colors can be improved.

  Further, as the color filters 24, 25 and 26, dichroic color filters may be used. When a dichroic color filter is used as the color filter, in order to improve the color separation characteristics, the incident angle to the dichroic color filter is not set to 0 ° of the specified value, for example, 45 °, and the center of the cutoff characteristic is shortened. It is necessary to take a method of moving to the wavelength side and smoothing the cutoff characteristics.

  Thus, a white LED and a color filter that transmits only light of a predetermined wavelength from the white LED are used as the light source. Therefore, complicated maintenance can be made unnecessary by using a white LED having excellent versatility.

  The photoelectric conversion unit 27 is composed of, for example, a photoelectric conversion element such as a photodiode, photoelectrically converts received light, and outputs a light intensity signal (current) corresponding to the light intensity. For example, S2387-66R manufactured by Hamamatsu Photonics is used as the photodiode.

  The I / V conversion unit 28 converts the light intensity signal output from the photoelectric conversion unit 27 into a voltage, and outputs the converted light intensity signal to the BPF units 301, 302, and 303 of the color measurement unit 3 described later. .

  The pulse lighting control unit 29 controls lighting of the white LEDs 21, 22, and 23, and pulses a plurality of light sources at different lighting frequencies. Specifically, the lighting frequencies of the white LEDs 21, 22, and 23 are values obtained by dividing the fundamental frequency by integer values that are relatively prime. For example, the lighting frequencies of the white LEDs 21, 22, and 23 are 17.6 kHz, 6.6 kHz, and 4.1 kHz obtained by dividing the fundamental frequency of 52.8 kHz by 3, 8, and 13, respectively. . As a result, the light intensity signal detected by the photoelectric conversion unit 27 is a combined signal mainly composed of three frequencies of 17.6 kHz, 6.6 kHz, and 4.1 kHz.

  The outer edge member 201 is made of aluminum, and has holes for receiving white LEDs 21, 22, 23 and color filters 24, 25, 26 on the side surfaces, and covers the entire probe unit 2 to block outside light. ing.

  The external light blocking member 202 blocks external light and reflects the light irradiated by the white LEDs 21, 22 and 23 in the irradiation light guide member 203. In the present embodiment, the lower end portion of the probe unit 2 is covered with the external light blocking material 202 and the upper end portion is covered with the outer edge member 201. However, all of them may be covered with the outer edge member 201.

  The light guide member 203 for irradiation is composed of a transparent acrylic pipe, and guides mixed light obtained by mixing the light irradiated by the white LEDs 21, 22, 23 to the test paper surface.

  The irradiation light reflecting material 204 has a cylindrical shape, is formed along the inner peripheral surface of the irradiation light guide member 203, and reflects the light irradiated by the white LEDs 21, 22, and 23 in the irradiation light guide member 203. .

  The light receiving light guide member 205 is made of a transparent acrylic rod, and guides the light reflected by the test paper 200 to the photoelectric conversion unit 27.

  FIG. 3 is an enlarged view showing an end portion of the irradiation light guide member 203 shown in FIG. 1. The light emitted by the white LEDs 21, 22, and 23 is incident on the irradiation light guide member 203. The incident light travels through the irradiation light guide member 203 while being reflected by both the inner wall of the outer edge member 201 and the inner wall of the outer light blocking member 202 and the irradiation light reflecting member 204, and in the meantime, the white LEDs 21, 22, 23. Light (light having a specific wavelength transmitted through the color filters 24, 25, and 26) is mixed. The mixed light thus mixed is reflected by the inner wall of the external light blocking member 202 at the tip of the irradiation light guide member 203 formed in a dome shape, and is irradiated onto the test paper 200. As shown in FIG. 3, the irradiation angle θ at which the mixed light is irradiated onto the test paper 200 is an angle at which the specularly reflected light on the surface to be measured does not directly enter the light receiving light guide member 205. By configuring, the color measurement accuracy can be kept good.

  In this embodiment, the end portion of the irradiation light guide member 203 on which light is incident on the measurement object is formed in a curved surface shape so that regular reflection light from the measurement object does not enter the light reception light guide member 205. The present invention is not particularly limited to this, and may have other shapes as long as the regular reflection light from the measurement object does not enter the light receiving light guide member 205.

  The reflected light guided by the light receiving light guide member 205 enters the photoelectric conversion unit 27 provided at the upper end of the outer edge member 201 and is converted into an electric signal by the photoelectric conversion unit 27. The electrical signal output from the photoelectric conversion unit 27 is converted from a current signal into a voltage signal proportional to the light intensity by an I / V conversion unit 28 provided in the immediate vicinity of the photoelectric conversion unit 27 in order to remove the influence of noise and the like. The

  As described above, the light from the plurality of white LEDs 21, 22, 23 incident from the outer peripheral surface is mixed and guided to the test paper 200 by the irradiation light guide member 203 having a cylindrical shape, and the outer edge member 201. The external light blocking material 202 covers the plurality of white LEDs 21, 22, and 23 and the irradiation light guide member 203 to block external light, and is provided along the inner peripheral surface of the irradiation light guide member 203. The light irradiated by the plurality of white LEDs 21, 22, and 23 is reflected by the irradiated light reflecting material 204, and the test paper is received by the light receiving light guide member 205 provided on the inner peripheral surface side of the irradiated light reflecting material 204. The reflected light reflected by 200 is guided to the photoelectric conversion unit 27.

  Therefore, it is possible to mix light having different wavelengths emitted from the plurality of white LEDs 21, 22, 23 without using an optical system, and more than when mixing light using a special optical system. Miniaturization can be realized.

  The probe unit 2 corresponds to an example of a light source device, the white LEDs 21, 22, 23 and the color filters 24, 25, and 26 correspond to examples of a plurality of light sources, and the irradiation light guide member 203 is an example of a light guide unit. The outer edge member 201 and the external light blocking material 202 correspond to an example of an external light blocking material, the irradiation light reflecting material 204 corresponds to an example of a reflecting member, and the photoelectric conversion unit 27 corresponds to an example of a photoelectric conversion unit. The color measuring unit 3 corresponds to an example of a color measuring unit, and the pulse lighting control unit 29 corresponds to an example of a lighting control unit.

  The color measuring unit 3 includes BPF (band pass filter) units 301, 302, and 303, RMS (root mean square) circuits 304, 305, and 306, LPF (low pass filter) units 307, 308, and 309, and an amplifier. 310, 311, 312, A / D converter 40, control unit 41, liquid crystal display unit 42, and switch unit 43.

  The BPF unit 301 extracts only the light intensity signal corresponding to the wavelength of the light transmitted through the color filter 24 from the combined signal having the lighting frequency of the white LED 21 as the center frequency and having a plurality of frequencies as main components. In the present embodiment, since the lighting frequency of the white LED 21 is 17.6 kHz, the center frequency of the BPF unit 301 is also 17.6 kHz, and light corresponding to red among the electrical signals output from the I / V conversion unit 28 is used. Pass only the intensity signal.

  The BPF unit 302 extracts only the light intensity signal corresponding to the wavelength of the light transmitted through the color filter 25 from the combined signal having the lighting frequency of the white LED 22 as the center frequency and having a plurality of frequencies as main components. In the present embodiment, since the lighting frequency of the white LED 22 is 6.6 kHz, the center frequency of the BPF unit 302 is also set to 6.6 kHz, and light corresponding to green among the electrical signals output from the I / V conversion unit 28 is used. Pass only the intensity signal.

  The BPF unit 303 extracts only the light intensity signal corresponding to the wavelength of the light transmitted through the color filter 26 from the combined signal whose main frequency is the lighting frequency of the white LED 23 and whose main component is a plurality of frequencies. In this embodiment, since the lighting frequency of the white LED 23 is 4.1 kHz, the center frequency of the BPF unit 303 is also 4.1 kHz, and light corresponding to blue among the electrical signals output from the I / V conversion unit 28 is used. Pass only the intensity signal.

  The RMS circuit 304 obtains an effective value equivalent amount of the light intensity signal that has passed through the BPF unit 301. The RMS circuit 305 obtains an effective value equivalent amount of the light intensity signal that has passed through the BPF unit 302. The RMS circuit 306 obtains an effective value equivalent amount of the light intensity signal that has passed through the BPF unit 303. That is, since the amplitude component of the light intensity signal that has passed through the BPF units 301, 302, and 303 is proportional to the light intensity, the RMS circuits 304, 305, and 306 obtain the effective value equivalent amount in order to extract the amplitude component.

  The LPF unit 307 smoothes the light intensity signal output from the RMS circuit 304. The LPF unit 308 smoothes the light intensity signal output from the RMS circuit 305. The LPF unit 309 smoothes the light intensity signal output from the RMS circuit 306.

  The amplifier 310 amplifies the light intensity signal output from the LPF unit 307. The amplifier 311 amplifies the light intensity signal output from the LPF unit 308. The amplifier 312 amplifies the light intensity signal output from the LPF unit 309.

  The A / D converter 40 converts the light intensity signal (analog signal) amplified by the amplifiers 310, 311, and 312 into a digital signal. The light intensity signals converted into digital signals by the A / D converter 40 are output to the control unit 41, respectively.

  The control unit 41 includes, for example, a microchip computer, and includes a normalization processing unit 411, a perceptual color information conversion unit 412, a measurement impossibility determination unit 413, an inspection item value estimation unit 414, and a display control unit 415. In addition, although the control part 41 in this embodiment is comprised by one microchip computer, this invention is not specifically limited to this, You may comprise by several microchip computers, and each function is comprised by several. Processing may be performed by being distributed to microchip computers.

  The normalization processing unit 411 normalizes outputs for red, green, and blue using the reflected light intensity of the white rough surface and the reflected light intensity of the black rough surface measured in advance. Specifically, the normalized reflected light intensity is calculated using the following equations (1) to (3).

R * = (R−R _black ) / (R _white −R _black ) (1)
G * = (G-G _black ) / (G _white -G _black ) (2)
B * = (B−B _black ) / (B _white −B _black ) (3)
In the above equations (1) to (3), R, G, and B represent reflected light intensity signals derived from red, green, and blue, and R _black , G _black , and B _black represent red with respect to the black rough surface. , Green and blue reflected light intensity signals, R _white , G _white , and B _white represent red, green, and blue reflected light intensity signals for a white rough surface, and R *, G *, and B * are normal The red, green, and blue reflected light intensity signals after conversion are shown. In this embodiment, red, green, and blue reflected light intensity signals R _black , G _black , and B _{black for the black} rough surface, and red, green, and blue reflected light intensity signals R _white , G _white , and B _white for the white rough surface. However, the present invention is not particularly limited to this, and the black rough surface and the white rough surface are measured before the user performs color measurement. You may set by measuring the reflected light of a surface.

  Thus, by using the reflected light intensity of the white rough surface and the reflected light intensity of the black rough surface measured in advance, it is possible to maintain high measurement accuracy by normalizing the detected light intensity signal. It is possible to diagnose abnormalities.

  The perceptual color information conversion unit 412 converts the output values for red, green, and blue normalized by the normalization processing unit 411 into perceptual color information including at least one of hue, saturation, and brightness. In this embodiment, the perceptual color information conversion unit 412 calculates the hue value in the perceptual color information as a numerical value of 0 ° or more and less than 360 ° in the hexagonal pyramid color model.

  The measurement impossibility determination unit 413 determines whether the measured perceptual color information is a measurable normal value based on the saturation converted by the perceptual color information conversion unit 412. That is, the measurement impossibility determination unit 413 compares the saturation converted by the perceptual color information conversion unit 412 with the specified saturation value stored in advance in the storage unit, and the saturation is equal to or less than the specified value. Judge that measurement is impossible.

  In this embodiment, it is determined whether or not measurement is possible using saturation, but the present invention is not particularly limited to this, and it is determined whether or not measurement is possible using brightness. May be. In this case, the measurement impossibility determination unit 413 compares the brightness converted by the perceptual color information conversion unit 412 with a specified value of brightness stored in the storage unit in advance, and if the brightness is equal to or less than the specified value, measurement is performed. Judge that it is impossible.

  In this manner, the saturation or brightness of the test paper 200 is calculated by the perceptual color information conversion unit 412 of the color measurement unit 3, and the pre-defined rule is set as the saturation or brightness calculated by the measurement impossibility determination unit 413. When the value is compared with the saturation or the lightness is equal to or less than the specified value, it is determined that measurement is impossible. Therefore, the abnormality of the apparatus or the abnormality of the measurement object can be detected, and the measurement accuracy can be stabilized.

  The inspection item value estimation unit 414 collects in advance the hue value of the test paper for the known inspection item value, the calibration curve parameter approximated according to the inspection item, and the hue converted by the perceptual color information conversion unit 412. The inspection item value is estimated using the value. For example, test items in urinalysis include hemoglobin, occult blood, urobilinogen, protein, glucose, pH, and the like, and test item values corresponding to the respective test items are estimated. When the test item value is represented by a logarithmic value such as pH, a calibration curve approximated based on the following equation (4) is used. When the test item value is not a logarithmic value such as glucose concentration, the following (5 A calibration curve approximated based on equation (1) is used.

In the above equations (4) and (5), value represents the inspection item value, hue represents the hue value, hue _max represents the hue value at the upper limit of the inspection item value, and hue _min represents Represents the hue value at the lower limit of the inspection item value, value ₀ represents the inspection item value giving the average hue value of hue _max and hue _min, and dv and p represent the degree of change in the hue value, respectively. It represents a coefficient.

  The calibration curves (sigmoid curves) shown in the above formulas (4) and (5) are effective in approximating the hue value change generated by the characteristic mixing ratio of two colors, and many color tests. It can be used for quantitative measurement. The setting of the parameters of the calibration curve affects the estimation accuracy of each inspection item value and can be set at home, but is calibrated by a test paper manufacturer such as urine test paper, and the color measuring apparatus 1 It is preferable that the user obtains and sets only the parameters by the communication unit included in the.

  When the parameters of the calibration curve are set, the inspection item value estimation unit 414 estimates each inspection item value from the hue value using the following equation (6) or (7). When the test item value is represented by a logarithmic value such as pH, it is estimated using the following formula (6). When the test item value is not a logarithmic value such as glucose concentration, the following formula (7) is used. Estimated.

In the above formulas (6) and (7), value represents the inspection item value, hue represents the hue value, hue _max represents the hue value at the upper limit of the inspection item value, and hue _min represents Represents the hue value at the lower limit of the inspection item value, value ₀ represents the inspection item value giving the average hue value of hue _max and hue _min, and dv and p represent the degree of change in the hue value, respectively. It represents a coefficient.

  The display control unit 415 controls to display the inspection item value estimated by the inspection item value estimation unit 414 on the liquid crystal display unit 42. The display control unit 415 controls the liquid crystal display unit 42 to display a notification screen for notifying the user that measurement is impossible when the measurement impossible determination unit 413 determines that measurement is impossible. .

  The liquid crystal display unit 42 displays the inspection item value estimated by the inspection item value estimation unit 414. In addition, when the liquid crystal display unit 42 determines that measurement is impossible by the measurement impossibility determination unit 413, the liquid crystal display unit 42 displays a notification screen for notifying the user that measurement is impossible.

  The switch unit 43 receives a power on / off input by the user and a measurement start instruction input by the user. The control unit 41 outputs a measurement start instruction signal to the pulse lighting control unit 29 when the switch unit 43 receives the measurement start instruction. When the measurement start instruction signal is input from the control unit 41, the pulse lighting control unit 29 starts pulse lighting of the white LEDs 21, 22, and 23. The switch unit 43 accepts selection of an inspection item desired by the user.

  Next, the operation of the color measuring apparatus according to the present invention will be described. FIG. 4 is a flowchart for explaining the operation of the color measuring apparatus 1 shown in FIG.

  First, in step S <b> 1, the control unit 41 receives a measurement start instruction from the user using the switch unit 43. The user operates a button provided on the switch unit 43 to instruct the start of measurement. When receiving the measurement start instruction, the control unit 41 outputs a measurement start instruction signal to the pulse lighting control unit 29.

  Next, in step S2, when the measurement start instruction signal is input from the control unit 41, the pulse lighting control unit 29 pulses the three white LEDs 21, 22, and 23 at different lighting frequencies. Light emitted from the white LEDs 21, 22, and 23 is transmitted through the color filters 24, 25, and 26, respectively, and is incident on the irradiation light guide member 203 as light of respective color components of red, green, and blue. The red, green, and blue light incident on the irradiation light guide member 203 are mixed in the irradiation light guide member 203. The mixed light is irradiated onto the test paper 200 from the end of the light guide member 203 for irradiation. The light reflected by the test paper 200 enters the light receiving light guide member 205 and is guided to the photoelectric conversion unit 27. The photoelectric conversion unit 27 converts the incident light into an electric signal (light intensity signal) corresponding to the light intensity. The light intensity signal converted by the photoelectric conversion unit 27 is converted into a voltage signal by the I / V conversion unit 28 and output to the BPF units 301, 302, and 303. The BPF units 301, 302, and 303 pass the light intensity signal in the same frequency band as the lighting frequency of the white LEDs 21, 22, and 23, thereby decomposing the light intensity signal of the mixed light, and each color component of red, green, and blue A light intensity signal corresponding to is output. The RMS values 304, 305, and 306 of the light intensity signals that have passed through the BPF units 301, 302, and 303 are calculated as effective values, smoothed by the LPF units 307, 308, and 309, and amplified by the amplifiers 310, 311 and 312. Amplified and output to the A / D converter 40. The light intensity signal converted into a digital signal by the A / D converter 40 is output to the control unit 41.

  Next, in step S3, the normalization processing unit 411 converts the output values for red, green, and blue converted into digital signals by the A / D converter 40, and the reflected light intensity of the white rough surface measured in advance and Normalization is performed using the reflected light intensity of the black rough surface.

  Next, in step S4, the perceptual color information conversion unit 412 converts the output values for red, green, and blue normalized by the normalization processing unit 411 into perceptual color information. Here, the perceptual color information conversion unit 412 converts each output value for red, green, and blue into at least a hue value and saturation.

  Next, in step S5, the measurement impossibility determination unit 413 determines whether or not the saturation converted by the perceptual color information conversion unit 412 is equal to or less than a predetermined value stored in advance. If it is determined that the saturation is not more than the specified value (YES in step S5), the process proceeds to step S6, and if it is determined that the saturation is greater than the specified value (NO in step S6). Then, the process proceeds to step S7.

  If it is determined that the saturation is equal to or less than the specified value, in step S6, the display control unit 415 controls to display on the liquid crystal display unit 42 a notification screen for notifying the user that measurement is impossible. . And the liquid crystal display part 42 displays the alerting | reporting screen for alert | reporting to a user that measurement is impossible, and complete | finishes a process.

  On the other hand, when it is determined that the saturation is larger than the specified value, the inspection item value estimation unit 414 responds to each inspection item based on the hue value converted by the perceptual color information conversion unit 412 in step S7. Estimate inspection item values. The inspection item value estimation unit 414 stores a calibration curve parameter obtained by measuring in advance for each inspection item, and estimates the inspection item value using this parameter.

  Next, in step S <b> 8, the display control unit 415 controls to display the inspection item value estimated by the inspection item value estimation unit 414 on the liquid crystal display unit 42. The liquid crystal display unit 42 displays the inspection item value estimated by the inspection item value estimation unit 414.

  Here, the conventional visual inspection and the inspection by the color measuring apparatus 1 will be compared and described. Table 1 below compares conventional visual urinalysis and urinalysis using a color measuring device for each inspection item. As test paper, Terumo urine test paper “Uriese-Te” was used.

  As shown in Table 1 above, when hemoglobin is inspected, the conventional visual inspection can only evaluate four levels, whereas the color measuring apparatus 1 can evaluate 155 levels. It became. Similarly, with respect to the other inspection items, the conventional inspection has several stages of evaluation, whereas the inspection by the color measuring apparatus 1 can evaluate from several tens to hundreds of stages.

  5 is a diagram showing the results of quantitative measurement of pH concentration and glucose concentration using the color measuring device 1, and FIG. 5 (a) is a quantitative measurement of pH concentration using the color measuring device 1. FIG. 5B is a diagram showing the result of quantitative measurement of glucose concentration using the color measuring device 1. In FIG. 5A, the vertical axis represents the measurement result of the pH concentration by the color measuring apparatus 1, and the horizontal axis represents the actual pH concentration. In FIG. 5B, the vertical axis represents the measurement result of the glucose concentration by the color measuring device 1, and the horizontal axis represents the actual glucose concentration. Further, white circles in FIGS. 5A and 5B are actual measurement values representing the measurement results obtained by the color measuring apparatus 1, and straight lines represent theoretical values. As shown in FIGS. 5 (a) and 5 (b), the measurement results of pH concentration and glucose concentration and the theoretical values almost coincide, and it can be seen that measurement can be performed with high accuracy.

  In addition, since the color change of a test paper is scarce at both ends of a measurement range, the deterioration of a measurement result is seen. In the measurement result of pH concentration shown in FIG. 5 (a), a measurement error occurs at pH 9 or higher, but considering that the normal value of pH is 4.8 to 7.5, in daily use, There is no particular problem. Even in the measurement result of glucose concentration shown in FIG. 5 (b), the accuracy of the measurement result in the extremely low concentration range is low, but when used in the home, such a low concentration measurement result is obtained. Since there is no possibility, the measurement accuracy is sufficient. These problems can be improved by using a urine test paper having a large color change.

  In this way, light of different wavelengths is irradiated by the plurality of white LEDs 21, 22, 23 and the color filters 24, 25, 26, respectively, and the plurality of white LEDs 21, 22, 23, and The mixed light obtained by mixing the light irradiated by the color filters 24, 25, and 26 is guided to the test paper 200 that is a measurement object. Then, the photoelectric conversion unit 27 receives the reflected light reflected by the test paper 200 and converts the received reflected light into a light intensity signal. The color measurement unit 3 decomposes the light intensity signal converted by the photoelectric conversion unit 27 for each wavelength of the plurality of light sources, and measures the color of the test paper 200 based on the decomposed light intensity signals.

  Therefore, the light intensity signal is decomposed for each wavelength of the plurality of light sources, and the color of the measurement object is measured based on the decomposed light intensity signal. Therefore, the light of the plurality of wavelengths is mixed without using an optical component. The mixed light can be decomposed and downsizing can be realized. Moreover, since it is excellent in portability, the user can perform urine tests and the like on a daily basis, and daily health management in home medical care is strengthened, which can greatly contribute to the welfare of an aging society.

  Further, a plurality of white LEDs 21, 22, and 23 are pulse-lit at different lighting frequencies, and the light intensity signals converted by the photoelectric conversion unit 27 by the plurality of BPF units 301, 302, and 303 having the lighting frequency as the center frequency are used. Since light intensity signals corresponding to the light of the wavelengths of the white LEDs 21, 22, and 23 are extracted, light of a plurality of wavelengths can be decomposed by an electric circuit, not by an optical component that increases the size of the device. Further, since optical parts such as a spectroscope are not required, the manufacturing cost can be reduced.

  Further, the hue measuring unit 200 calculates the hue value of the test paper 200 whose coloration state changes with respect to the inspection item, and estimates the inspection item value corresponding to the coloration state based on the calculated hue value. Therefore, it is possible to quantitatively measure the inspection item value instead of the stepwise visual measurement as in the conventional case.

  In this embodiment, the number of light sources is three. However, the present invention is not particularly limited to this, and the sample may be irradiated with mixed light obtained by mixing light emitted from two or more light sources. . In this case, the lighting frequency of each light source is set to be relatively prime, and the signal processing circuit is designed to smooth the effect of simultaneous blinking that occurs at the common multiple with a low-frequency pass filter, thereby developing a wide range of sensors. Can also be applied.

  In this embodiment, the test item value is estimated by measuring the color of a test paper such as a urine test paper. However, the present invention is not particularly limited to this, for example, by human visual inspection. The present invention can be used for various devices that perform color measurement, and can also be used for a color measurement device that mainly uses human perception information such as painting and printed matter, and a color presentation device for acquired visually impaired persons.

It is a figure which shows the structure of the color measuring apparatus which concerns on this invention. It is a figure which shows roughly the characteristic of the transmittance | permeability distribution of each color filter. It is a figure which expands and shows the edge part of the light guide member for irradiation shown in FIG. 3 is a flowchart for explaining the operation of the color measuring apparatus shown in FIG. It is a figure which shows the result of having performed the quantitative measurement of pH concentration and glucose concentration using the color measuring apparatus 1. FIG.

Explanation of symbols

1 color measuring device 2 probe unit 3 color measuring unit 21, 22, 23 white LED
24, 25, 26 Color filter 27 Photoelectric conversion unit 28 I / V conversion unit 29 Pulse lighting control unit 40 A / D converter 41 Control unit 42 Liquid crystal display unit 43 Switch unit 201 Outer edge member 202 External light blocking material 203 Irradiation guide Optical member 204 Irradiation light reflector 205 Light receiving light guide member 301, 302, 303 BPF unit 304, 305, 306 RMS circuit 307, 308, 309 LPF unit 310, 311, 312 Amplifier 411 Normalization processing unit 412 Perceptual color information conversion Unit 413 measurement impossibility determination unit 414 inspection item value estimation unit 415 display control unit

Claims (8)

A color measuring device for measuring the color of a measurement object,
A plurality of light sources that emit light of different wavelengths,
A light guide means for guiding mixed light, which is a mixture of light irradiated by the plurality of light sources, to the measurement object;
Photoelectric conversion means for receiving reflected light reflected by the measurement object and converting the received reflected light into a light intensity signal;
A color measurement unit that decomposes the light intensity signal converted by the photoelectric conversion unit for each wavelength of the plurality of light sources and measures the color of the measurement object based on the decomposed light intensity signal. Color measuring device. Further comprising lighting control means for pulse-lighting the plurality of light sources at different lighting frequencies,
The color measuring unit has a plurality of bandpass filters whose center frequency is the lighting frequency, and corresponds to light of each light source wavelength from the light intensity signal converted by the photoelectric conversion unit using each bandpass filter. The color measuring apparatus according to claim 1, wherein a light intensity signal to be extracted is extracted.   3. The color measuring apparatus according to claim 2, wherein the lighting control means pulse-lights each light source at a relatively low lighting frequency. The measurement object includes a test paper whose coloration state changes with respect to a predetermined inspection item,
The color measurement unit calculates a hue value of the test paper, and calculates an inspection item value corresponding to the coloration state based on the calculated hue value. The described color measuring device.   The light source includes a white LED and a color filter that transmits only light having a wavelength corresponding to any one color component of red, green, and blue from light irradiated by the white LED. The color measuring device according to claim 1.   6. The color measuring apparatus according to claim 5, wherein the color filter has a characteristic that the transmittance distribution changes gradually with respect to the wavelength. A light source device that irradiates a measurement object with light and receives light reflected by the measurement object by a light receiving unit,
A plurality of light sources that emit light of different wavelengths,
A light receiving member for receiving light that guides the reflected light reflected by the measurement object to the light receiving unit;
A reflecting member provided outside the light receiving light guide member and reflecting light emitted by the plurality of light sources;
A light guide member for irradiation that is provided outside the reflective member and that mixes light from a plurality of light sources incident from the outer peripheral surface thereof and guides the light to a measurement object;
An external light blocking material that covers the plurality of light sources and the irradiation light guide member and blocks external light.   The end portion of the irradiation light guide member on which light is incident on the measurement object is formed in a curved surface shape so that regular reflection light from the measurement object does not enter the light reception light guide member. Item 8. The light source device according to Item 7.

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