JP2006234471A - Spectral colorimetry device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a spectral colorimetry device capable of two-dimensionally measuring the color distribution of an object to be measured even if the object is of continuous length without using any two-dimensional expensive movable carriages, and capable of calibration easily by a reference white plate. <P>SOLUTION: The spectral colorimetry device comprises an illumination means for applying light beams; a section for moving the object to be measured by placing the object to be measured for travel; a spectral imaging section for imaging the object to be measured; an image capturing section for capturing image data; an arithmetic section for performing color operation from the image data; a display section for displaying the result of the color operation; a control section for controlling the spectral capturing section, the illumination means, and the section for moving the object to be measured; and the reference white plate for calibrating the spectral state of the object to be measured for measuring the color of the object to be measured. The spectral colorimetry device can freely change the irradiation position of light beams from the object to be measured to the reference white plate, and arranges a light switching rocking section for rocking the light beams so that the detail of the object to be measured or the reference white plate can be irradiated with light beams at the intermediate position between the object to be measured and the reference white plate. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a spectrocolorimetric apparatus that can measure a quantitative color distribution of an object to be measured such as a plate in two dimensions.

  Spectral colorimetry devices that measure optical characteristics such as quantitative color and reflectance of the measurement object have different wavelength characteristics depending on the light source intensity, detector sensitivity, measurement temperature, etc. Calibration with a reference sample is required during measurement. Patent Documents 1 to 3 disclose a spectrocolorimetric device including a reference white plate serving as a reference sample.

  First, in the spectrocolorimetric apparatus described in JP-A-6-50818, calibration is performed by switching reflected light from a reference white plate or an object to be measured by rotating a plane mirror. Further, in the spectrocolorimetric device described in JP-A-8-159876, calibration is performed by switching reflected light from a reference white plate or an object to be measured by a prism. These spectroscopic devices are convenient in that they can be calibrated by switching reflected light without moving the reference white plate. However, it is basically point measurement, and the color distribution of the object to be measured cannot be measured in two dimensions.

On the other hand, in the spectrocolorimetric apparatus described in Japanese Patent Application Laid-Open No. 11-101692, calibration is performed by placing a flat object to be measured and a reference sample on a moving table and moving the moving table. ing. By using this spectrocolorimeter, it is possible to measure the color distribution of a plate-like object to be measured in two dimensions.
JP-A-6-50818 JP-A-8-159876 Japanese Patent Laid-Open No. 11-101692

  However, the spectrocolorimetric apparatus described in Japanese Patent Application Laid-Open No. 11-101692 requires an expensive two-dimensional moving table in order to measure the color distribution of a plate-like object to be measured in two dimensions. . Further, when the object to be measured becomes longer and larger, the moving table on which the object to be measured needs to be longer and larger, which further increases the price. In addition, when the object to be measured is long and large, the distance for moving the moving base for measuring the reference white plate becomes long, and the time required for calibration becomes long.

  The present invention has been made in view of the above-described problems, and the object of the present invention is to use a long object to be measured without using an expensive two-dimensional moving table. Another object of the present invention is to provide a spectrocolorimetric apparatus that can measure a color distribution in two dimensions and can be easily calibrated with a reference white plate.

  In order to solve the above-described problems, a spectrocolorimetric apparatus according to the present invention includes an illumination unit that irradiates a measurement object with a light beam, a measurement object moving unit that places and moves the measurement object, and the measurement object. A spectral imaging unit that captures the image, an image capturing unit that captures image data from the captured imaging data, a computing unit that performs color computation from the image data, and a display unit that displays a result of color computation of the computing unit, A spectrophotometer that has a control unit that controls the spectral imaging unit, the illumination unit, and the measurement object moving unit, and a reference white plate for calibrating the spectral state of the measurement object, and performs colorimetry on the measurement object. The color device can freely change the irradiation position of the light beam from the object to be measured to the reference white plate, and also shake the light beam so that the light beam can irradiate the details of the object to be measured or the reference white plate. A moving light-switching oscillating part is placed in the middle of the measured object and the reference white plate It is characterized in that it comprises Te.

  Since the spectrocolorimetric apparatus of the present invention includes a measured object moving unit and a light switching swing unit, a two-dimensional moving table is used even for a long plate-shaped measured object. In addition, the color distribution of the object to be measured can be measured two-dimensionally, and can be easily calibrated with a reference white plate.

(Embodiment 1)
The spectral colorimetry apparatus of this embodiment will be described with reference to FIGS. As shown in FIG. 1, the spectral colorimetric apparatus of the present embodiment measures the color distribution of a long plate-like object 1 such as an exterior material in a two-dimensional manner, and is an illumination means, xenon. A light source 2, a plane mirror 3 and a rotating unit 4 constituting a light switching oscillating unit, a conveyor 5 as a measured object moving unit, a reference white plate 6, a CCD camera 7 constituting a spectral imaging unit and an optical path The switch unit 8, the image capture unit 9, the calculation unit 10, the display unit 11, and the control unit 12 are included.

  First, the measured object 1 is a long plate, and the xenon light source 2 is a light source for irradiating the measured light beam 15 to the measured object 1 and the reference white plate 6. This has the advantage of being close to the spectrum distribution of sunlight as an artificial light source, and has an advantage that it has a longer life than a halogen lamp and has a stable wavelength spectrum.

  The plane mirror 3 has a function of changing the direction of the light beam 15 emitted from the xenon light source 2 and irradiating the measurement object 1 and the reference white plate 6. The plane mirror 3 is attached to the rotating unit 4. The plane mirror 3 can be rotated in the directions of P and P ′ by a motor or the like built in the rotation unit 4. That is, as shown in FIG. 1A, normally, the light beam 15 is reflected by the plane mirror 3 and irradiates the object 1 to be measured. On the other hand, as shown in FIG. 1B, when the calibration is performed, the rotating mirror 4 rotates the plane mirror 3 by 90 degrees in the P direction so that the light beam 15 irradiates the reference white plate 6. become. Further, by rotating the plane mirror 3 by a minute angle by the rotation unit 4, the light beam 15 can move and measure the details of the measurement object 1 or the reference white plate 6.

  Moreover, the conveyance conveyor 5 mounts the long to-be-measured object 1 in flat form, and enables it to move to Q direction. As the conveyor 5, a commercially available belt conveyor can be used.

  The reference white plate 6 is a white plate that serves as a reference for spectral colorimetric calibration, and the width of the reference white plate 6 is at least the width of the object to be measured 1. The reference white plate 6 is fixed to the spectrocolorimeter and does not move. Here, as shown in FIG. 2, the plane mirror 3 is disposed at an intermediate position between the measured object 1 and the reference white plate 6, and the measured object 1 and the reference white plate 6 are located with respect to the plane mirror 3. The relationship is equidistant.

  Further, the CCD camera 7 and the optical path switch unit 8 constitute a spectral imaging unit that images the measurement object 1 or the reference white plate 6. First, the optical path switch unit 8 switches the optical path of the light beam 15 applied to the object to be measured 1 or the reference white plate 6 in the direction of the CCD camera 7, which includes a glass substrate 16 and a prism 17. ing. First, as shown in FIG. 3A, when the light beam 15 irradiates the object 1 to be measured, the optical path switch unit 8 is moved to the R side according to a command from the control unit 12, and the glass substrate is moved. The light beam 15 passes through 16 and is irradiated to the CCD camera 7. On the other hand, as shown in FIG. 3B, when the light beam 15 irradiates the reference white plate 6, the optical path switch unit 8 is moved to the R ′ side according to a command from the control unit 12, and the prism is moved. At 17, the light beam 15 is reflected and irradiated onto the CCD camera 7. Here, the CCD camera 7 receives the light beam 15 reflected by the measurement object 1 or the reference white plate 6 for a certain exposure time and converts it into an electrical signal.

  Further, the image capturing unit 9 has a function of capturing image data from image data of an electrical signal captured by the CCD camera 7, and the arithmetic unit 10 has a function of performing color calculation from the image data. The display unit 11 has a function of displaying the result of the color calculation. The control unit 12 has a function of controlling the operations of the xenon light source 2, the conveyor 5, the CCD camera 7, the optical path switch unit 8, and the rotation unit 4.

  Hereinafter, the operation of the spectral colorimetric apparatus of the present embodiment will be described. First, the measurer places the measurement object 1 on the conveyor 5. Prior to spectral colorimetry of the object 1 to be measured, spectral colorimetry of the reference white plate 6 is performed for calibration. For this purpose, according to a command from the control unit 12, the rotating unit 4 is operated so that the light beam 15 is irradiated onto the reference white plate 6 by the plane mirror 3, and the plane mirror 3 is rotated in the P direction. At the same time, the optical path switch unit 8 is moved to the R ′ side, and the prism 17 causes the light beam 15 to enter the CCD camera 7 from the reference white plate 6. In this state, as shown in FIG. 1B, the light beam 15 is irradiated from the xenon light source 2, and the light beam passes through the path of the xenon light source 2 → the plane mirror 3 → the reference white plate 6 → the prism 17 → the CCD camera 7. 15 enters the CCD camera 7. Further, in this state, the light beam 15 is irradiated so that the light beam 15 is irradiated in the order of details A ′ → B ′ → C ′ of the reference white plate 6 by rotating the rotating unit 4 by a minute angle in the direction of P. 15 is swung. At this time, the light beam 15 is spectrally imaged by the CCD camera 7, and the imaging data at this time is stored in the arithmetic unit 10 as calibration data.

  Next, the rotating unit 4 is operated to rotate the plane mirror 3 by 90 degrees in the P ′ direction so that the light beam 15 irradiates the measurement object 1 as shown in FIG. At the same time, the optical path switch unit 8 switches the portion through which the light beam 15 passes to the glass substrate 16 to the R side. In this way, the light beam 15 is irradiated from the xenon light source 2, and the light beam 15 enters the CCD camera 7 through the path of the xenon light source 2 → the plane mirror 3 → the object to be measured 1 → the glass substrate 16 → the CCD camera 7. Let Further, in this state, the conveyor 5 is driven to move the measurement object 1 in the Q direction. Then, the plane mirror 3 is rotated within a small angle range, and the light beam 15 is oscillated so that the light beam 15 irradiates the details of the measurement object 1 in the order of A → B → C → B → A.

  Here, as shown in FIG. 2, the spectrocolorimetric apparatus of the present embodiment has a distance from the point X where the light beam 15 is irradiated onto the plane mirror 3 to the details A, B, and C of the object 1 to be measured, The distances between the details A ′, B ′, and C ′ of the reference white plate 6 are equal (XA = XA ′, XB = XB ′, XC = XC ′), and from the point Y of the CCD camera 7, the measurement object 1 The distances to the details A, B and C of the reference white and the details A ′, B ′ and C ′ of the reference white plate 6 are equal (YA = YA ′, YB = YB ′, YC = YC ′), respectively. The incident angles of the light beam 15 with respect to the measurement object 1 and the reference white plate 6 are also geometrically arranged. This means that the measured object 1 and the reference white plate 6 have the same relationship between the wavelength and phase until the light beam 15 irradiated from the xenon light source 2 is reflected and enters the CCD camera 7. I mean. Accordingly, the reference white plate 6 can correctly calibrate the spectral colorimetric result of the object 1 to be measured.

  Next, when the wavelength of the xenon light source 2 changes or the ambient temperature changes while the object to be measured 1 is spectrophotometrically measured for a long time, the light beam 15 irradiates the reference white plate 6. Thus, the plane mirror 3 is rotated 90 degrees in the P direction. In this way, the reference white plate 6 is again spectrally measured, and the obtained result is stored in the arithmetic unit 10 as calibration data. After this, the plane mirror 3 is again rotated 90 degrees in the P ′ direction so that the light beam 15 irradiates the measurement object 1 and the spectral colorimetry of the measurement object 1 is continued.

Here, when the diameter of the light beam 15 is φ, the frequency at which the details on the object to be measured 1 are swung is f, and the speed at which the object 1 is moved in the Q direction by the conveyor 5 is V, the following relationship is established. The formula holds.
φf ≧ V
As shown in FIG. 4, this means that the diameter of the light beam 15 is larger than the distance that the conveyor 5 moves in the Q direction during the time that the light beam 15 swings on the measurement object 1 for one period. Indicates that is larger. Therefore, the light beam 15 can be irradiated on the object to be measured 1 over the entire range. In particular, if the plane mirror 3 is swung at a frequency f at which φ = fV, the entire range of the object 1 can be spectrophotometrically measured.

  Further, when the light beam 15 irradiates A and C which are the end portions of the measurement object 1 and A ′ and C ′ which are the end portions on the reference white plate 6, the light beam 15 which is irradiated from the xenon light source 2. When the light beam 15 irradiates B, which is the central portion of the object 1 to be measured, and B ′, which is the central portion on the reference white plate 6, the light beam emitted from the xenon light source 2 is increased. The irradiation amount of the light beam 15 of the illuminating means is changed according to the light swing angle at which the light beam 15 is swung so that the irradiation amount of 15 is reduced. By doing so, it is possible to make the irradiation amount of the light beam 15 irradiated to each detail on the measurement object 1 and the reference white plate 6 the same.

  Further, as described above, even if the irradiation amount of the light beam 15 of the xenon light source 2 is not changed in accordance with the light swing angle at which the light beam 15 is swung, the end portion of the measurement object 1 is not changed. When the light beam 15 irradiates A ′ and C ′ and A ′ and C ′ which are the end portions on the reference white plate 6, the exposure time of the CCD camera 7 is lengthened and the central portion of the measurement object 1 is set. When the light beam 15 irradiates a certain B or B ′ which is the central portion on the reference white plate 6, the exposure time of the CCD camera 7 is lengthened, and the exposure time of the spectral imaging unit is set according to the light oscillation period. It may change. This also makes it possible to make the irradiation amount of the light beam 15 applied to the CCD camera 7 from the details on the measurement object 1 and the reference white plate 6 the same.

  The spectral colorimetric apparatus of the present embodiment includes an illumination unit that irradiates a measurement object with a light beam, a measurement object moving unit that places and moves the measurement object, and a spectral imaging unit that images the measurement object. An image capture unit that captures image data from the captured image data, a computation unit that performs color computation from the image data, a display unit that displays a result of color computation of the computation unit, a spectral imaging unit, illumination means, A spectrocolorimetric apparatus that includes a control unit that controls a measurement object moving unit and a reference white plate for calibrating the spectral state of the measurement object, and that performs spectral colorimetry on the measurement object, Since the irradiation position of the beam can be freely changed from the measured object to the reference white plate, the spectral white color measurement result of the measured object is correctly corrected by the reference white plate without moving the measured object and the reference white plate. It can be easily calibrated. In addition, since the light switching oscillating unit that oscillates the light beam is arranged at an intermediate position between the object to be measured and the reference white plate so that the light beam can irradiate the details of the object to be measured or the reference white plate, Even if it is a to-be-measured object, the color distribution of the to-be-measured object can be measured two-dimensionally using an inexpensive one-dimensional moving apparatus without using an expensive two-dimensional moving table.

  In addition, the spectral colorimetric apparatus of the present embodiment has a light beam width larger than the numerical value obtained by multiplying the light oscillation period for oscillating the light beam in the light switching oscillating unit by the moving speed of the measured object moving unit. The light beam on the object to be measured can be irradiated over the entire range. For this reason, the color distribution can be measured by two-dimensional spectral colorimetry over the entire range of the object to be measured.

  In addition, since the spectral colorimetric apparatus of the present embodiment changes the light beam irradiation amount of the illuminating means according to the light swing angle at which the light beam is swung in the light switching rocking unit, the object to be measured and the reference The amount of light beam applied to each detail on the white plate can be the same. For this reason, the colorimetric data of the object to be measured can be calibrated more accurately.

  Furthermore, since the spectral colorimetric apparatus of the present embodiment changes the exposure time of the spectral imaging unit according to the light oscillation period, the spectral imaging unit is irradiated from each detail on the measurement object and the reference white plate. The amount of light beam irradiation can be the same. For this reason, the spectral colorimetric data of the object to be measured can be calibrated more accurately.

(Embodiment 2)
The spectral colorimetry apparatus of this embodiment will be described with reference to FIG. The configuration of the spectrocolorimetric apparatus is almost the same as that of the first embodiment, but the structure of the light switching oscillating unit is different as shown in FIG. This part will be mainly described.

  As shown in FIG. 5, the spectral colorimetric apparatus of this embodiment includes a fixed plane mirror 18 that first reflects the light beam 15 emitted from the xenon light source 2, and the light switching oscillating unit includes a light oscillating unit and a light oscillating unit. It consists of a light switching unit. Here, the light oscillating unit is configured to irradiate the details of the DUT 1 or the reference white plate 6, and includes a first plane mirror 19 that reflects the light beam 15 from the fixed plane mirror 18, and the first plane mirror 19. And a first rotation portion 21 that rotates the lens at a minute angle. The light switching unit is configured to freely change the irradiation position of the light beam 15 from the object to be measured 1 to the reference white plate 6, and rotates the second plane mirror 20 by 90 degrees. It is comprised by the 2nd rotation part 22 to move.

  In the spectral colorimetry apparatus of this embodiment, in order to perform spectral colorimetry of the measurement object 1, as shown in FIG. 5, the light beam 15 is irradiated from the xenon light source 2, and the xenon light source 2 → the fixed plane mirror 18 → the first one. The object to be measured 1 is imaged by irradiating the CCD camera 7 with the light beam 15 through a path of 1 plane mirror 19 → second plane mirror 20 → measurement object 1 → optical path switch unit 8 (glass substrate 16) → CCD camera 7. . In this state, the first rotating unit 21 is operated to swing the first plane mirror 19 by rotating it by a minute angle, and the light beam 15 is irradiated to the details of the measurement object 1. At this time, the to-be-measured object 1 is spectrally measured over the entire range by moving the conveyor 5 in the Q direction. By doing so, the spectral distribution of the DUT 1 can be measured in two dimensions.

  On the other hand, in order to measure the reference white plate 6 for calibration, the second rotating unit 22 is operated to rotate the second plane mirror 20 by 90 degrees, so that the light beam 15 is changed to the reference white plate. 6 is irradiated. In this state, in this state, the first rotating unit 21 is operated to swing the first plane mirror 19 by rotating it by a minute angle so that the light beam 15 is irradiated to the details of the reference white plate 6. . By doing so, the reference white plate 6 can be subjected to spectral colorimetry, and calibration data can be measured.

  Here, the 1st rotation part 21 rotates the 1st plane mirror 19 only a minute angle, and the 2nd rotation part 22 rotates the 2nd plane mirror 20 only 90 degree | times. Therefore, each rotation mechanism is an extremely simple mechanism and easy to control as compared with the rotation mechanism of the rotation unit of the first embodiment. For this reason, even if the number of parts increases, the overall price can be reduced.

  In the spectrocolorimetric apparatus of the present embodiment, the light switching oscillating unit includes a light oscillating unit capable of irradiating the details of the object to be measured or the reference white plate by rotating the first plane mirror at a minute angle, A light switching unit that can freely change the irradiation position of the light beam from the object to be measured to the reference white plate by rotating the two-plane mirror by 90 degrees. An optical rocking unit that rotates within a minute angle range and an optical switching unit that can rotate only 90 degrees can be provided. For this reason, it becomes possible to make each rotation mechanism simpler, and it can also be made inexpensive.

  In this embodiment, the light beam emitted from the xenon light source is first reflected by the fixed plane mirror. However, if the xenon light source is arranged in the direction in which the light beam is incident on the first plane mirror, the fixed plane mirror can be omitted. Is also possible.

(Embodiment 3)
The spectral colorimetry apparatus of this embodiment will be described with reference to FIG. The configuration of the spectrocolorimetric apparatus is almost the same as that of the first embodiment, except that a first lens 23 and a second lens 24, which are telecentric optical means, are provided as shown in FIG. Yes. This part will be mainly described.

  As shown in FIG. 6A, the spectral colorimetric apparatus of the present embodiment is configured such that the light beam 15 emitted from the xenon light source 2 is reflected by the plane mirror 3 in the direction of the object 1 to be measured. The light passes through one lens 23 and is irradiated to the object 1 to be measured at the same incident angle. As shown in FIG. 6B, when the light beam 15 is reflected by the plane mirror 3 in the direction of the reference white plate 6, it passes through the second lens 24 to the reference white plate 6. Irradiated at the same incident angle.

  The spectrocolorimetric apparatus of the present embodiment has telecentric optical means arranged between the light switching oscillating unit and the object to be measured and between the light switching oscillating unit and the white reference plate. The plate can be irradiated at the same incident angle. For this reason, it is possible to make the light beam irradiation amount irradiated to each detail on the object to be measured and the reference white plate the same, and calibrate the colorimetric data of the object to be measured more accurately. In addition, even if there are irregularities on the surface of the object to be measured or the reference white plate, it is possible to capture details.

  The first lens 23 and the second lens 24, which are telecentric optical means, may be separate objects, but may be configured to rotate one lens. When one lens is rotated, it is configured to rotate simultaneously when the optical path of the light beam is changed from the object to be measured to the reference white plate by the light switching oscillating unit. By adopting such a configuration, the same telecentric optical means can be used for the object to be measured and the reference white plate, and the calibration accuracy can be improved.

It is a perspective view of the spectral colorimetric apparatus of Embodiment 1, (a) is the state which is irradiating the to-be-measured object, (b) is the state which is irradiating the reference | standard white board. It is a figure which shows the geometric arrangement | positioning of the spectral colorimetry apparatus of Embodiment 1. FIG. 2A and 2B are perspective views of a CCD camera and an optical path switch unit of the spectral colorimetry apparatus according to the first embodiment, in which FIG. 3A is a state in which an object to be measured is irradiated, and FIG. It is. FIG. 3 is a top view showing the diameter of the light beam and the swing range of the first embodiment. It is a perspective view of the spectral colorimetry apparatus of Embodiment 2. It is a perspective view of the spectral colorimetry apparatus of Embodiment 3, (a) is the state which has irradiated the to-be-measured object, (b) is the state which has irradiated the reference | standard white board.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Object to be measured 2 Xenon light source 3 Plane mirror 4 Rotating part 5 Conveyor 6 Reference white plate 7 CCD camera 8 Optical path switch part 9 Image capture part 10 Calculation part 11 Display part 12 Control part 15 Light beam 16 Glass substrate 17 Prism 18 Fixed plane mirror 19 1st plane mirror 20 2nd plane mirror 21 1st rotation part 22 2nd rotation part 23 1st lens 24 2nd lens

Claims (6)

Illumination means for irradiating the measurement object with the light beam, a measurement object moving unit for placing and moving the measurement object, a spectral imaging unit for imaging the measurement object, and image data from the captured imaging data Control for controlling an image capture unit to be captured, a computation unit that performs color computation from the image data, a display unit that displays the result of color computation of the computation unit, a spectral imaging unit, illumination means, and a measured object moving unit A spectrocolorimetric device for measuring the color of the object to be measured, comprising a reference white plate for calibrating the spectral state of the object to be measured,
Light switching oscillation that can change the irradiation position of the light beam freely from the object to be measured to the reference white plate, and also oscillates the light beam so that the light beam can irradiate the details of the object to be measured or the reference white plate. A spectrocolorimetric apparatus, characterized in that a portion is arranged at an intermediate position between an object to be measured and a reference white plate.   The light switching oscillating unit rotates the first plane mirror by a minute angle to rotate the light oscillating unit capable of irradiating the details of the object to be measured or the reference white plate and the second plane mirror by 90 degrees. The spectral colorimetric apparatus according to claim 1, further comprising: a light switching unit that can freely change the irradiation position of the light beam from the object to be measured to the reference white plate.   The width of the light beam is larger than a numerical value obtained by multiplying a light oscillation period for oscillating the light beam in the light switching oscillating unit by the moving speed of the measured object moving unit. The spectrocolorimetric device described.   4. The light beam irradiation amount of the illuminating means is changed in accordance with a light swing angle for swinging the light beam in the light switching swing section. Spectral color measuring device.   5. The spectral colorimetric apparatus according to claim 1, wherein an exposure time of the spectral imaging unit is changed according to the light oscillation period. 6. The spectrocolorimetric apparatus according to claim 1, wherein telecentric optical means is disposed between the light switching oscillating portion and the object to be measured.

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