JP2009008561A - Spectral characteristic measuring apparatus and spectral characteristic measuring system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a spectral characteristic measuring apparatus and spectral characteristic measuring system allowing a user to easily manage the accuracy of measurement. <P>SOLUTION: When an accuracy recognizing switch is pushed (YES in #11), a control section calculates a wavelength shift amount Δλ using a white calibration plate and a xenon flash lamp (#12-#17), and calculates a spectral reflectance characteristic obtained by shifting the spectral reflectance characteristic stored in a spectro-colorimeter 1 at the factory delivery by the wavelength shift amount Δλ (#18). The control section compares the spectral reflectance characteristic (c) with a previously stored spectral reflectance characteristic (a) obtained by a measuring operation by a master machine, calculates the error of the spectral reflectance characteristic (c) from the spectral reflectance characteristic (a) obtained by the measuring operation by the master machine, and displays the error on a display section (#20). <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a technical field of a spectral characteristic measuring apparatus such as a spectrocolorimeter that measures a spectral reflection characteristic of a measurement sample.

  Spectral characteristic measurement devices such as a spectrocolorimeter that measure the spectral reflection characteristics of a measurement sample are used to produce the amplitude and center of the spectral sensitivity of the light-receiving means using an emission line spectrum such as a laser or a temperature-controlled color reference plate. Shipped after calibrating wavelength and half width. However, if the spectral sensitivity of the light receiving means is shifted in the wavelength spectral direction due to changes over time or environmental changes after shipment, there is a problem that the measurement accuracy decreases.

  For example, a light receiving means generally having a plurality of photoelectric conversion elements arranged at predetermined intervals in the wavelength spectral direction of the spectroscopic means and receiving light of different wavelengths and outputting electric signals according to the light intensity is used. However, in that case, if the relative position between the light receiving means and the spectroscopic means changes in the wavelength spectroscopic direction due to changes over time, the spectral sensitivity of the light receiving means shifts in the wavelength spectroscopic direction.

  To solve this problem, generally, a color reference plate with a known spectral reflectance is measured, and the wavelength shift amount is estimated and corrected from the difference between the obtained measurement value and the known measurement value (reference value). Things have been done.

  Specifically, a manufacturer (manufacturer) of a spectral characteristic measuring apparatus usually manages a spectral characteristic measuring apparatus (hereinafter referred to as a master machine) as a reference in order to manage measurement accuracy in the spectral characteristic measuring apparatus shipped as a product. When the spectral characteristic measurement device for products is shipped, the measurement operation of the color reference plate is performed by the spectral characteristic measurement device for the product, and the measured value is the measurement operation of the master machine. Is calibrated so as to substantially match the measured value (reference value) of the color reference plate obtained in the above.

Then, the user requests the color reference plate from the manufacturer in order to perform accuracy management to check the fluctuation of accuracy due to the temporal change of the spectral characteristic measuring device or the ambient temperature change, and the manufacturer uses the spectral characteristic measuring device in use. The measurement operation is performed on the color reference plate sent from, and the difference between the measured value and the measured value by the master machine is confirmed (see Patent Document 1 below). In addition to this method, a method is also used in which the user sends the spectral characteristic measuring apparatus used by the user to the manufacturer and requests the manufacturer to perform the accuracy management.
US Pat. No. 6,559,944

  However, in the former accuracy management method, if the state of the color reference plate changes after the color reference plate sent from the manufacturer arrives at the user, accurate accuracy management of the spectral characteristic measuring device is performed. Since this is not possible, the user needs to strictly manage the color reference plate so that the surface of the color reference plate is not damaged or faded.

  In the latter accuracy management method, since the user cannot perform a measurement operation using the spectral characteristic measuring apparatus during the period when the user returns the spectral characteristic measuring apparatus to the manufacturer, the accuracy management is performed. It is practically difficult to carry out frequently, and there is a concern that the measurement operation cannot always be performed with high accuracy.

  Furthermore, in common with both of the accuracy management methods, when there are a plurality of types of color reference plates, the user or manufacturer needs to perform a measurement operation for each color reference plate when performing accuracy management, which is very time-consuming. There is also a problem of this.

  The present invention has been made in view of this, and provides a spectral characteristic measuring apparatus and a spectral characteristic measuring system that allow a user to easily manage measurement accuracy.

  The invention according to claim 1 is an illumination unit that emits light, a spectroscopic unit that splits reflected light or transmitted light from a measurement sample by an illumination operation of the illumination unit into light of each wavelength, and a wavelength by the spectroscopic unit A plurality of photoelectric conversion elements arranged at predetermined intervals in the spectroscopic direction, each photoelectric conversion element receiving light of a different wavelength and outputting a light reception signal corresponding to the light intensity; and each photoelectric conversion A spectral profile generation unit that generates a spectral profile based on a light reception signal output from the element, and calculates a spectral characteristic of the measurement sample from the spectral profile generated by the spectral profile generation unit, A first storage unit that stores in advance the spectral characteristics of the color reference plate measured in advance by the spectral characteristic measuring apparatus, and a current sensitivity to the spectral sensitivity characteristics of the light receiving unit at a predetermined time. A wavelength shift amount calculation unit that calculates a change in spectral sensitivity characteristics of the light receiving unit as a wavelength shift amount, a wavelength shift amount calculated by the wavelength shift amount calculation unit, and a spectral characteristic stored in the first storage unit And a calculation unit for calculating the spectral characteristic of the color reference plate obtained when the spectral characteristic of the color reference plate is measured using the current spectral sensitivity characteristic of the light receiving unit, and the spectral calculated by the calculation unit An error calculation unit is provided that compares the characteristic with the spectral characteristic of the color reference plate measured in advance by another predetermined spectral characteristic measuring device and calculates an error between the two.

  According to the present invention, first, the wavelength shift amount calculation unit calculates the current change in the spectral sensitivity characteristic of the light receiving unit with respect to the spectral sensitivity characteristic of the light receiving unit at a predetermined time as the wavelength shift amount. Next, based on the spectral characteristics of the color reference plate measured in advance by the spectral characteristic measuring device and stored in advance in the first storage unit, and the wavelength shift amount calculated by the wavelength shift amount calculation unit, The spectral characteristic of the color reference plate obtained when the spectral characteristic of the color reference plate is measured with the current spectral sensitivity characteristic of the light receiving unit is calculated by the calculation unit, and the calculated spectral characteristic by the error calculation unit, An error between the two is calculated by comparing the spectral characteristics of the color reference plate measured in advance with another predetermined spectral characteristic measuring apparatus.

  Thus, in the present invention, the spectral characteristics of the color reference plate obtained when the spectral characteristics of the color reference plate are measured with the spectral sensitivity characteristics of the current light receiving section, and other predetermined spectral characteristics measurement. An error from the spectral characteristic of the color reference plate measured in advance by the apparatus is calculated by the spectral characteristic measuring apparatus. The other predetermined spectral characteristic measuring apparatus is preferably an apparatus for performing accuracy management of the spectral characteristic measuring apparatus according to the present invention, and the color measured in advance by another predetermined spectral characteristic measuring apparatus. The spectral characteristic of the reference plate is preferably a standard spectral characteristic used when performing the accuracy control.

  According to a second aspect of the present invention, in the spectral characteristic measuring apparatus according to the first aspect, the second storage unit that stores the spectral characteristic of the color reference plate measured in advance by the other spectral characteristic measuring apparatus is further provided. The error calculation unit reads the spectral characteristic of the color reference plate measured in advance by the other spectral characteristic measurement device from the second storage unit and calculates the error.

  According to this invention, the spectral characteristic measuring device stores the spectral characteristics of the color reference plate measured in advance by the other spectral characteristic measuring device (master machine), so that it can be obtained from a recording medium or communicated. As a result, it is possible to further save the user's trouble as compared with a configuration obtained from another device.

  According to a third aspect of the present invention, the spectral characteristic measuring apparatus according to the first or second aspect further includes a display unit that displays the error calculated by the error calculation unit.

  According to the present invention, since the error calculated by the error calculation unit is displayed on the display unit, the user confirms the error displayed by the display unit, and the error of the light receiving unit due to a change over time, an environmental change, or the like. It is possible to grasp a change in spectral sensitivity and an error included in the spectral characteristics of the color reference plate measured by the spectrometer.

  According to a fourth aspect of the present invention, there is provided a spectral characteristic measuring system including the spectral characteristic measuring device according to the first or second aspect and a display unit that displays an error calculated by the error calculating unit.

  According to the present invention, in the spectral characteristic measurement system, the user can confirm the error displayed by the display unit and the spectrum of the light receiving unit due to a change over time or an environmental change. It is possible to obtain an effect that it is possible to grasp a change in sensitivity and an error included in the spectral characteristics of the color reference plate measured by the spectrometer.

  According to the present invention, the spectral characteristics of the color reference plate obtained when the spectral characteristics of the color reference plate are measured with the spectral sensitivity characteristics of the current light receiving unit, and previously measured with another predetermined spectral characteristic measuring device. Since an error from the spectral characteristic of the color reference plate is calculated by the spectral characteristic measuring apparatus, it is not necessary for the user to strictly manage the color reference plate. Further, in order for the user to know the current state of the spectral characteristic measuring apparatus, it is not necessary for the user to perform an operation of measuring the spectral characteristic of the color reference plate using the spectral measuring apparatus. Therefore, it is possible to easily manage the accuracy of the spectral characteristic measuring apparatus without requiring troublesome work and a lot of time.

  An embodiment of a spectral characteristic measuring apparatus according to the present invention will be described. FIG. 1 is a configuration diagram schematically showing a spectrocolorimeter which is an embodiment (first embodiment) of a spectral characteristic measuring apparatus according to the present invention, and FIG. 2 is an electrical diagram of a light emitting circuit of the spectrocolorimeter. FIG.

  As shown in FIG. 1, the spectrocolorimeter 1 includes an integrating sphere 10, a light emitting circuit 20, a sample light measurement unit 30, a reference light measurement unit 40, an input operation unit 50, and a control unit 60, which are used. Thus, the spectral reflection characteristic of the measurement sample 2 is measured.

  The integrating sphere 10 is a hollow sphere in which a white diffuse reflecting paint such as magnesium oxide or barium sulfate having a high diffusibility and high reflectance is applied to the inner wall 11, and a light source installed inside the integrating sphere 10. The light beam from the xenon flash lamp 12 (an example of the illumination unit) is reflected by the inner wall 11 to generate diffused light. FIG. 1 is a side sectional view of the integrating sphere 10.

  The integrating sphere 10 has a sample opening 13 drilled at the lower end and a light receiving opening drilled in a direction inclined by a predetermined angle (for example, 8 °) with respect to the normal 13n of the opening surface of the sample opening 13. 14. A light shielding wall 15 is disposed below the xenon flash lamp 12 so that light rays from the xenon flash lamp 12 do not directly irradiate the sample opening 13.

  The light emitting circuit 20 causes the xenon flash lamp 12 to emit light. As shown in FIG. 2, a main capacitor 21 for applying a high DC voltage of several hundred volts to the electrode of the xenon flash lamp 12, A charging circuit 22 for charging, a trigger generating circuit 23 for applying an instantaneous high voltage of several tens of thousands of volts to a trigger electrode 12a made of a metal wire wound in close contact with the xenon flash lamp 12, and a diode 24 such as an IGBT And a driving circuit 26 for applying a driving voltage to the semiconductor switching element 25.

  With the semiconductor switch element 25 turned on and a high DC voltage applied to both end electrodes of the xenon flash lamp 12 by the main capacitor 21, the trigger capacitor of the trigger generation circuit 23 applies a high voltage to the trigger electrode 12a via the trigger transformer. Is instantaneously applied, a direct current flows from the main capacitor 21 and the xenon flash lamp 12 emits light. By controlling the timing at which the semiconductor switch element 25 is turned off after the light emission of the xenon flash lamp 12 is started, the light emission time of the xenon flash lamp 12 can be controlled.

  Returning to FIG. 1, the sample light measuring unit 30 includes a light receiving optical system 31, an optical fiber 32, and a sample light spectroscopic unit 33. The light receiving optical system 31 is disposed in the vicinity of the light receiving opening 14 of the integrating sphere 10 and reflects reflected light (hereinafter referred to as “sample light”) from the sample 2 that is disposed in the sample opening 13 and is diffusely illuminated. Among them, the component 14a in the predetermined angle (8 °) direction with respect to the normal line 13n is focused and imaged on the incident end of the optical fiber 32. The reflected light image of the measurement sample 2 is sampled by the optical fiber 32. Guided to section 33.

  The sample light spectroscopic unit 33 includes an infrared light blocking filter 34, a diffraction grating 35, and a sample light sensor array 36. The infrared light blocking filter 34 is disposed close to the emission end of the optical fiber 32, and blocks light in a wavelength region of, for example, 800 nm or more. The diffraction grating 35 is an example of a spectroscopic unit, and spectroscopically reflects sample light incident through the infrared light blocking filter 34 for each wavelength and reflects the sample light. In this embodiment, a reflective concave diffraction grating is used, but a transmission diffraction grating may be used.

  The sample optical sensor array 36 is composed of a plurality of photoelectric conversion elements arranged in the wavelength spectral direction split by the diffraction grating 35, and receives light of different wavelengths and outputs an electrical signal corresponding to the light intensity. is there. The sample optical sensor array 36 is an example of a light receiving unit.

  In the present embodiment, the spectral reflectance characteristics (an example of spectral characteristics) of the measurement sample 2 are measured at a measurement wavelength range of 380 nm to 780 nm and a measurement pitch of 10 nm, and 41 sample optical sensor arrays 36 are provided. The photoelectric conversion element (hereinafter referred to as “sensor”). If each sensor and wavelength are specified using the sensor number i given to each sensor of the sample photosensor array 36 and the wavelength number j given to the wavelength in the measurement wavelength range, the sample photosensor array 36 is: 41 sensors from sensor number i = 0 to sensor number i = 40 are provided. Further, the measurement wavelength range is measured from a wavelength number j = 0 to a wavelength number j = 40 at a pitch of 10 nm. When the wavelength of the wavelength number j is expressed as λj, the value of λj is a pitch of 10 nm, for example, λ0 = 380 nm, λ40 = 780 nm. The integrating sphere 10 and the sample light measuring unit 30 constitute a spectrocolorimeter 1 having a d / 8 geometry.

  The reference light measurement unit 40 includes an optical fiber 41 and a reference light spectroscopic unit 42. The incident end of the optical fiber 41 is disposed at an appropriate position of the integrating sphere 10 (for example, a position where the light beam from the xenon flash lamp 12 and the sample light are not directly irradiated), and the diffused light in the integrating sphere 10 is transmitted as reference light by the optical fiber 41. The light is guided to the reference light spectroscopic unit 42.

  The reference light spectroscopic unit 42 has substantially the same configuration as the sample light spectroscopic unit 33. That is, for example, an infrared light blocking filter 43 that blocks light in a wavelength range of 800 nm or more, a concave diffraction grating 44 that spectrally reflects and reflects reference light incident through the infrared light blocking filter 43 for each wavelength, and concave diffraction A reference light sensor array 45 including a plurality of photoelectric conversion elements arranged in a wavelength spectral direction split by the grating 44 is provided. A transmission diffraction grating may be used instead of the concave diffraction grating 44. The reference light spectroscopic unit 42 is used during white calibration described later.

  The input operation unit 50 is disposed on the surface of the apparatus main body, and includes a power switch 51 for switching on / off the power of the spectrocolorimeter 1, a measurement switch 52 for instructing measurement start of spectral reflectance characteristics, and the spectral measurement An accuracy check switch 53 for setting the colorimeter 1 to an accuracy check mode described later is provided.

  The input operation unit 50 also includes a white calibration switch (not shown). When this white calibration switch is operated, a known white calibration, for example, a white calibration plate as disclosed in Japanese Patent Application Laid-Open No. 2003-90761 is provided. A white calibration using is performed. The white calibration plate is usually attached to the spectrocolorimeter 1 in order to perform this white calibration. The spectrocolorimeter 1 includes a display unit 80 including an LCD for displaying measurement results and the like.

  The control unit 60 includes a storage unit including a rewritable memory such as a ROM or EEPROM in which a reference spectral profile obtained in advance or a control program is stored, and a RAM for temporarily storing data, and the storage unit And a CPU that operates in accordance with a control program stored in the, and controls the operation of the spectrocolorimeter 1 as a whole.

  In addition, the control unit 60 functionally includes an illumination control unit 61, a spectral profile generation unit 62, a mode setting unit 63, a feature amount calculation unit 64, a wavelength shift amount calculation unit 65, and a first spectral reflectance. A characteristic storage unit 66, a second spectral reflectance characteristic storage unit 67, a conversion unit 68, an error calculation unit 69, and a display control unit 70 are provided.

  When the measurement switch 52 or the accuracy confirmation switch 53 is pressed, the illumination control unit 61 controls the light emission of the xenon flash lamp 12 by sending a control signal to the light emitting circuit 20.

  The spectral profile generation unit 62 corresponds to the spectral profile generation unit, and includes a sensor number i of each sensor in the sample optical sensor array 36 and an output (spectral intensity) obtained from the sensor of the sensor number i. A spectral profile indicating the correspondence is generated.

  The mode setting unit 63 sets the operation mode of the spectrocolorimeter 1 according to the operation status of the input operation unit 50. The spectrocolorimeter 1 of the present embodiment has a normal measurement mode for measuring the measurement sample 2 and an accuracy for deriving the wavelength shift amount and confirming the current measurement accuracy of the spectrocolorimeter 1. The mode setting unit 63 sets the spectrocolorimeter 1 to the accuracy confirmation mode when the accuracy confirmation switch 53 is operated, and otherwise (mainly the measurement switch 52 is operated). The normal measurement mode is set.

  The feature amount calculation unit 64 calculates the feature amount used to derive the wavelength shift amount based on the spectral profile generated by the spectral profile generation unit 62 when the accuracy setting mode is set by the mode setting unit 63. To do. Hereinafter, an example of the calculation method of the feature amount will be described.

  In the present embodiment, as described above, the xenon flash lamp 12 is configured to emit light not only in the normal measurement mode but also in the accuracy check mode, and the bright line included in the output light of the xenon flash lamp 12 For example, the feature amount A is calculated using a bright line having a wavelength of 530 nm.

  FIG. 4A is a diagram for explaining the spectral sensitivity characteristics of each sensor constituting the sample optical sensor array 36, and the spectral sensitivity characteristics of some sensors (for example, 3 sensors out of 41) are extracted. FIG. FIG. 4B is a diagram showing a spectral distribution of a xenon flash lamp in a specific wavelength range, and FIG. 4C is a diagram showing a spectral profile.

  As shown in FIG. 4A, each sensor has spectral sensitivity characteristics having peaks in different wavelength ranges. The peak value in the spectral sensitivity characteristic of each sensor is normalized by a conventionally known method.

  As shown in FIG. 4B, when the spectral sensitivity characteristic of the sample optical sensor array 36 does not shift in the wavelength spectral direction, the wavelength range of the bright line having a wavelength of about 530 nm, the sensor It is assumed that the wavelength range corresponding to the peak value in the spectral sensitivity characteristic of the sensor with the number i is substantially associated. For example, the output of the sensor with the sensor number i-1 is Xi-1, and the output of the sensor with the sensor number i is Assuming that the output value of the sensor with sensor number i + 1 is represented by Xi + 1, the output value Xi of the sensor with sensor number i having received the bright line having the wavelength of about 530 nm is very high, as shown in FIG. The output values Xi−1 and Xi + 1 of the sensors with sensor numbers i−1 and i + 1 located on both sides of the sensor are significantly smaller than the output value Xi + 1. That.

  Here, in the present embodiment, the difference (Xi + 1) between the output values Xi−1 and Xi + 1 of the sensors with sensor numbers i−1 and i + 1 located on both sides of the sensor with sensor number i that has received the bright line having the wavelength of about 530 nm. -Xi-1) is derived as the feature amount A.

  This is because (1) using the difference in the output value of the sensor across the wavelength region where the emission line spectrum exists, when the spectral sensitivity characteristic shift occurs, one output value increases and the other output value decreases. As a result, the difference between the output values of the sensors changes relatively greatly. Therefore, the difference between the output values of the sensor is considered to be very effective as a parameter that can clearly grasp the occurrence of the shift. (2) The feature amount is calculated using the difference between the output values of the two sensors. The calculation is based on the reason that the offset amount of each sensor output can be canceled.

  In the present embodiment, the bright line having a wavelength of about 530 nm is used. However, the present invention is not limited to this, and a bright line having a wavelength of about 542 nm may be used. The feature amount is based on the bright line in the wavelength region of 520 nm to 550 nm. Should be calculated.

  The feature amount is calculated based on the bright line in the wavelength range of 520 nm to 550 nm as described above in the direction substantially perpendicular to the wavelength spectroscopic direction and the light receiving surface of the sample optical sensor array 36 (direction of arrow C in FIG. 1). When the sample optical sensor array 36 is moved (displaced), the relative position shift in the wavelength spectroscopic direction of the light to be incident on the sample optical sensor array 36 increases as the sensor is located at the end portion. This is because the position shift of the sensor located in the position is the smallest.

  Therefore, as described above, the measurement wavelength range of the sample optical sensor array 36 is 380 nm to 780 nm, and the sensor corresponding to the wavelength range of 520 nm to 550 nm is a substantially central portion of the sample optical sensor array 36 in the wavelength spectroscopic direction. Therefore, even if the sample optical sensor array 36 is moved (displaced) in the direction intersecting the wavelength spectroscopic direction by calculating the feature amount A using the light reception signal of the photoelectric conversion element. Thus, it is possible to calculate a feature value that is faithful to the positional deviation generated in the wavelength spectral direction.

  The wavelength shift amount calculation unit 65 derives the wavelength shift amount Δλ in the wavelength spectral direction of the spectral sensitivity characteristic of the sample optical sensor array 36. When the feature amount A is derived by the feature amount calculation unit 64, the wavelength shift amount calculation unit 65 is a feature in the initial state (for example, a state at the time of factory shipment) of the feature amount A and the spectral profile previously derived. The amount of change ΔA (= A−A0) is calculated by comparing with the amount A0, and the wavelength shift amount Δλ is derived based on the following equation.

Δλ = a × ΔA (1)
Note that a is a constant indicating the ratio of the change amount of the wavelength shift amount to the change amount of the feature amount A.

  The first spectral reflectance characteristic storage unit 66 stores the spectral reflectance characteristics of the color reference plate (for example, orange tile) measured by the spectral colorimeter 1 at the time of shipment from the factory. The second spectral reflectance characteristic storage unit 67 stores the spectral reflectance characteristics of the color reference plate measured by the master machine M (see FIG. 7). The master machine M is a device that serves as a reference for managing the measurement accuracy of the spectrocolorimeter 1 used by the user (the spectrocolorimeter 1 shipped as a product). The color reference plate is a member used when measuring the measurement accuracy of the spectrocolorimeter 1.

  The conversion unit 68 corresponds to the calculation unit, and stores the wavelength shift amount Δλ derived by the wavelength shift amount calculation unit 65 in the first spectral reflectance storage unit 66 using a predetermined conversion formula. The spectral reflectance characteristics (spectral reflectance characteristics indicated by arrow A in FIG. 3) of the color reference plate measured at the time of shipment from the factory are shifted by the wavelength shift amount Δλ (indicated by arrow B in FIG. 3). The spectral reflectance characteristics shown in FIG. That is, the conversion unit 68 has a spectral sensitivity characteristic shifted from the spectral sensitivity characteristic of the sample photosensor array 36 stored in the control unit 60 by the wavelength shift amount Δλ (the current spectral sensitivity characteristic of the sample photosensor array 36). A spectral reflectance characteristic of the color reference plate is calculated when it is assumed that the measurement is performed by the sample optical sensor array 36 having

  The error calculation unit 69 stores the spectral reflectance characteristic after the conversion processing by the conversion unit 68 with respect to the spectral reflectance characteristic of the color reference plate measured by the master machine M and stored in the second spectral reflectance storage unit 67. Is calculated.

  The display control unit 70 causes the display unit 80 to display the error calculated by the error calculation unit 69. The display unit 80 includes an LCD (Liquid Crystal Display) or the like, and displays the spectral reflectance characteristic (measurement result) of the measured measurement sample, and also displays the error calculated by the error calculation unit 69.

  5 is a flowchart showing processing performed at the time of factory shipment, FIG. 6 is a flowchart showing error display processing performed by the spectrocolorimeter 1 that has undergone the processing shown in FIG. 5, and FIG. 7 is processing performed at the time of factory shipment. It is a figure which shows the whole image of the said error display process.

  As shown in FIGS. 5 and 7, the worker sets a color reference plate such as an orange tile at the time of shipment from the factory, and sets the spectral reflectance characteristics of the color reference plate set using the spectrocolorimeter 1. The spectral reflectance characteristic (b) obtained by the measurement is stored in the spectral colorimeter 1 (step # 2).

  Further, as shown in FIG. 7, before the spectral colorimeter 1 is shipped, the spectral reflectance characteristic (a) of the color reference plate is measured by the master machine M, and this spectral reflectance characteristic (a ) Is stored in the spectrocolorimeter 1. In the spectrocolorimeter 1, the spectral reflectance characteristic (b) of the color reference plate obtained by the measurement operation at the time of factory shipment becomes the spectral reflectance characteristic (a) obtained by the measurement operation of the master machine M. As described above, the sample optical sensor array 36 is shipped in a state in which the spectral sensitivity characteristic is calibrated.

  When the spectrocolorimeter 1 is used by the user through the processing shown in FIG. 5, the accuracy check switch 53 is pressed with the white calibration plate set by the user as shown in FIGS. If so (YES in step # 11), the control unit 60 sets the spectrocolorimeter 1 to the accuracy confirmation mode (step # 12), and the predetermined time τ (for example, τ) shorter than the light emission time in the normal measurement mode. = 50 μs), the xenon flash lamp 12 is caused to emit light (step # 13).

  Then, the control unit 60 generates a spectral profile as shown in FIG. 4C, for example, based on the output of each sensor of the sample optical sensor array 36 (step # 14), and the feature amount A based on this spectral profile. Is calculated (step # 15). As described above, the feature amount A is obtained by detecting a sensor that has received a bright line and obtaining a value related to a difference in output values of sensors located on both sides of the sensor.

  Next, the control unit 60 compares the calculated feature amount A with the feature amount A0 in the initial state to calculate the change amount ΔA (step # 16), and using the change amount ΔA, the equation ( Based on 1), a wavelength shift amount Δλ is calculated (step # 17).

  Further, the control unit 60 calculates a spectral reflectance characteristic (c) obtained by shifting the spectral reflectance characteristic (b) stored in step # 2 of FIG. 5 by the wavelength shift amount Δλ calculated in step # 17 (step). # 18). Then, the control unit 60 compares the spectral reflectance characteristic (c) with the spectral reflectance characteristic (a) obtained by the measurement operation by the master machine M, which is stored in advance, and the measurement by the master machine M is performed. An error of the spectral reflectance characteristic (c) with respect to the spectral reflectance characteristic (a) obtained by the operation is calculated (step # 19), and this error is displayed on the display unit 80 (step # 20).

  As described above, in the spectrocolorimeter 1 according to the present embodiment, the optical arrangement of the diffraction grating 35 and the sample light sensor array 36 changes due to a change with time, a change in ambient temperature, and the like. Even if the spectral reflectance characteristic of the sample photosensor array 36 measured by the spectroscopic colorimeter 1 is shifted in the wavelength spectral direction by changing the relative position between the image and the sample photosensor array 36, the spectral reflectance is increased. Since the error with respect to the spectral reflectance characteristic obtained by the measurement operation by the master device M is notified to the user, the user can change the spectral sensitivity characteristic of the sample photosensor array 36 or the spectral side color meter 1. It is possible to grasp whether an error included in the spectral reflectance characteristic of the measured sample optical sensor array 36 is included.

  In particular, according to the present embodiment, the spectral reflectance characteristic storage unit 66 stores the spectral reflectance characteristic (b) of the color reference plate previously measured by the spectral colorimeter 1 at the time of factory shipment and the master machine M in advance. The measured spectral reflectance characteristic (a) of the color reference plate is stored in advance before shipment from the factory, and when the accuracy check switch 53 is operated by the user after shipment from the factory, the spectral sensitivity of the sample photosensor array 36 is measured. With respect to the characteristics, a process of calculating the amount of change from the time of shipment from the factory to the present time as the wavelength deviation amount Δλ, and the spectral reflectance characteristics (b) stored in the spectral reflectance characteristic storage unit 66 are converted into the wavelength deviation amount Δλ. And the calculated spectral reflectance characteristic (c) and the spectral reflectance characteristic (a) stored in the spectral reflectance characteristic storage unit 66. Calculate the error and Since the spectrocolorimeter 1 executes the process of displaying the image on the display unit 80, in order for the user to know the current state (measurement accuracy) of the spectrocolorimeter 1, the user can determine the spectrocolorimeter. The error is automatically calculated by the spectrocolorimeter 1 without performing an operation of measuring the spectral reflectance characteristics of the color reference plate using the meter 1. Therefore, it is possible to easily manage the accuracy of the spectrocolorimeter 1 without requiring the strict management of the color reference plate and the calibration work of the apparatus as in the past without requiring a troublesome work and a lot of time.

  The present case includes the following modification in addition to or in place of the embodiment.

  [1] In the first embodiment, when the accuracy check switch 53 is operated by the user, the process for calculating and displaying the error is executed. However, in this case, the process is executed. The trigger is not limited to the form based on the instruction from the user. For example, the form in which the spectrocolorimeter 1 automatically executes the processing at a constant cycle, or the environment of the spectrocolorimeter 1 (for example, the environmental temperature). ) Is also an assumed range when it is detected that the change is relatively large.

  [2] In the first embodiment, the spectroscopic colorimeter 1 includes the display unit 80 that displays the error. However, the present invention is not limited to this, and for example, the display body and the spectrocolorimeter 1 communicate with each other. The form in which the data indicating the error calculated by the spectrocolorimeter 1 is transmitted to the display body, and the display body displays the received data indicating the error is also an assumed range. . In the first embodiment, the spectral reflectance characteristic (a) data obtained by the measurement operation by the master machine M is stored in the spectrocolorimeter 1 in advance before shipment. It is not necessary to store the characteristic (a) data in the spectrocolorimeter 1 before shipping. For example, the spectral reflectance characteristic (a) data can be stored from an external device via a communication network or via a recording medium. The form to acquire can also be assumed.

  [3] Based on the assumption that the difference (change amount) ΔA between the feature amount A0 in the initial state of the spectral profile and the calculated feature amount A and the wavelength shift amount Δλ are approximately proportional, Although the wavelength shift amount Δλ is calculated based on this, the calculation formula for calculating the wavelength shift amount Δλ is not limited to the formula (1). Further, the relationship between the difference ΔA and the wavelength shift amount Δλ is stored in a table format, and when the feature amount A is calculated, the table is referred to and the wavelength shift amount corresponding to the difference ΔA based on the feature amount A is referred to. Δλ may be derived.

  [4] The method for deriving the wavelength shift amount Δλ is not limited to the method shown in the first embodiment, and for example, the method disclosed in Japanese Patent Laid-Open No. 2003-90761 proposed by the present applicant is also adopted. Is possible.

  [5] In the first embodiment, the spectroscopic characteristic measuring apparatus that measures the reflected light from the measurement sample has been described. However, the transmitted light type that measures a liquid, a transmissive plate-shaped measurement sample, or the like is used. The present invention is applied even to a spectral characteristic measuring apparatus. In this case, as the spectral profile used when calculating the feature amount, a spectral profile obtained without placing the measurement sample (through) may be used, and instead of the spectral reflectance characteristics of the sample in the first embodiment. Thus, the present invention can be applied to the spectral transmittance characteristic in exactly the same manner.

It is a block diagram which shows typically the spectral colorimeter which is one Embodiment of the spectral characteristic measuring apparatus which concerns on this invention. It is a figure which shows the electrical structure of the light emission circuit of a spectrocolorimeter. It is a figure for demonstrating the process by the conversion part. (A) is a figure for demonstrating the spectral sensitivity (spectral responsivity) of each sensor which comprises a sample optical sensor array, (b) is a figure which shows the spectral distribution of the xenon flash lamp in a specific wavelength range, ( c) is a diagram showing a spectral profile. It is a flowchart which shows the process performed at the time of factory shipments. It is a flowchart which shows the error display process performed with the spectrocolorimeter which passed through the process shown in FIG. It is a figure which shows the whole image of the process performed at the time of factory shipment, and the said error display process.

Explanation of symbols

61 Illumination control unit 62 Spectral profile generation unit 63 Mode setting unit 64 Feature amount calculation unit 65 Wavelength shift amount calculation unit 66 Spectral reflectance storage unit 67 Conversion unit 68 Error calculation unit 69 Display control unit 70 Display unit M Master machine

Claims (4)

An illumination unit that emits light;
A spectroscopic unit that divides the reflected light or transmitted light from the measurement sample by the illumination operation of the illumination unit into light of each wavelength;
A light receiving unit that has a plurality of photoelectric conversion elements arranged at predetermined intervals in a wavelength spectroscopic direction by the spectral unit, and each photoelectric conversion element receives light of a different wavelength and outputs a light reception signal according to the light intensity; ,
A spectral profile generation unit that generates a spectral profile based on a light reception signal output from each of the photoelectric conversion elements,
In the spectral characteristic measurement apparatus that calculates the spectral characteristics of the measurement sample from the spectral profile generated by the spectral profile generation unit,
A first storage unit that stores in advance the spectral characteristics of the color reference plate measured in advance by the spectral characteristic measuring apparatus;
A wavelength shift amount calculating unit that calculates a change in the current spectral sensitivity characteristic of the light receiving unit with respect to the spectral sensitivity characteristic of the light receiving unit at a predetermined time as a wavelength shift amount;
Based on the wavelength shift amount calculated by the wavelength shift amount calculation unit and the spectral characteristics stored in the first storage unit, the spectral characteristics of the color reference plate are measured with the current spectral sensitivity characteristics of the light receiving unit. A calculation unit for calculating the spectral characteristics of the color reference plate obtained in the case of
An error calculating unit that compares the spectral characteristic calculated by the calculating unit with a spectral characteristic of the color reference plate measured in advance by another predetermined spectral characteristic measuring device and calculates an error between the two. Spectral characteristic measuring device. A second storage unit for storing spectral characteristics of the color reference plate measured in advance by the other spectral characteristic measuring device;
2. The spectral characteristic measuring apparatus according to claim 1, wherein the error calculating unit reads the spectral characteristic of the color reference plate measured in advance by the other spectral characteristic measuring apparatus from the second storage unit and calculates the error. .   The spectral characteristic measuring apparatus according to claim 1, further comprising a display unit that displays an error calculated by the error calculation unit. The spectral characteristic measuring apparatus according to claim 1 or 2,
A spectral characteristic measurement system comprising: a display unit that displays an error calculated by the error calculation unit.

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