JP2010117149A - Two-dimensional colorimeter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To miniaturize a scanning mechanism and to reduce a scanning time thereof in a two-dimensional colorimeter used as an inspection device for a display. <P>SOLUTION: Light input from a two-dimensional measuring target object 2 through an objective lens 3 is sequentially incident on filters 7X, 7Y, 7Z by a micromirror array 4 formed of a DMD or MEMS having a plurality of micromirrors 4a arranged in a two-dimensional structure. The transmitted light is imaged at one point of an imaging position by image-forming lenses 8X, 8Y, 8Z. The light intensity is measured by means of a common use two-dimensional array sensor 9, and an arithmetic operation section 10 determines chromaticities x, y of respective points in the two-dimensional measuring target object. Accordingly, miniaturization of the scanning mechanism and reduction of a measuring (scanning) time period thereof can be achieved. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention is used as a display inspection device or the like, and is a two-dimensional colorimetric device that measures each color by sequentially scanning each point in a measurement object having a two-dimensional spread by an integration time of a predetermined light. About.

A general colorimetric device measures the color of a spot area on the surface of a measurement object, but an apparatus capable of two-dimensional measurement is required to measure the color of a wide measurement area. Therefore, as such a two-dimensional colorimetric apparatus, Patent Document 1 proposes a stimulus value direct reading type colorimetric method that can measure the color of an object or a light source with a simpler structure than a spectrocolorimeter. According to the prior art, measurement is performed by sequentially switching and arranging three to four types of filters corresponding to tristimulus values (X, Y, Z) in front of the two-dimensional array sensor. The degree x and y are obtained.
JP 2003-42848 A

  However, in the above-described prior art, the filter switching is performed by rotating the disk in which the filter is fitted, which is very large, making it difficult to reduce the size of the apparatus, and reliability (durability). There is a problem that is low. Further, there is a problem that it takes time to switch the filter and time is required for measurement (scanning).

  An object of the present invention is to provide a two-dimensional colorimetric apparatus that can be miniaturized and can reduce measurement time.

  The two-dimensional colorimetric device of the present invention is a stimulus value direct-reading type two-dimensional colorimetric device that measures the color at each point in a two-dimensional measurement object. A micromirror array capable of reflecting light incident through a lens by sequentially scanning in three or more different directions outside the optical path from the objective lens, and outside the optical path from the objective lens to the micromirror array From the two-dimensional sensor unit that receives the light scanned in the three or more reflection directions of the micromirror array and the light intensity measured by each sensor element of each two-dimensional sensor unit, And an arithmetic unit that calculates the color at each point in the measurement object.

  According to said structure, it is used as an inspection apparatus etc. of a display, and the two-dimensional colorimetry which measures each color sequentially by scanning each point in a two-dimensional measuring object with the integration time of predetermined light In the apparatus, a light path from the objective lens is incident on the light incident through the objective lens by a micromirror array in which a plurality of micromirrors are two-dimensionally arranged and made of DMD (Dgital Micromirror Device), MEMS (Micro Electro Mechanical Systems), or the like. Outside, the micromirror array sequentially scans in three or more different directions and reflects (deflects) the intensity of the reflected (deflected) light outside the optical path from the objective lens to the micromirror array. Measured with the stimulus value direct reading type (filter type) two-dimensional sensor unit arranged in each of the three or more reflection directions, and calculated from the measurement results. There calculates the color of each point in the measurement object of the two-dimensional.

  Therefore, when measuring the color of each point in the two-dimensional measurement object, the respective points are sequentially scanned by a slight displacement of the micromirror array made of DMD, MEMS, etc., so that the mechanism for scanning is reduced in size. And the measurement (scanning) time can be shortened.

  In the two-dimensional colorimetric apparatus of the present invention, the two-dimensional sensor unit is provided with a filter corresponding to each of the tristimulus values, and corresponding to each filter individually, and the transmitted light from the filter is determined in advance. It includes an imaging lens that forms an image at one imaging position and a two-dimensional array sensor that is arranged at the one imaging position.

  According to the above configuration, even if there are three reflection directions by the micromirror array and filters are arranged at the respective reflection positions, the transmitted light is collected at one point by the imaging lens, and the light intensity at each point is collected there. A two-dimensional array sensor for measuring is arranged.

  Therefore, the two-dimensional array sensor can be shared in a time-sharing manner, and each of the three stimulus values can be measured.

  Furthermore, in the two-dimensional colorimetric apparatus of the present invention, the three or more directions are mutually on a plane having a predetermined offset angle with respect to the optical axis of the objective lens and in a direction orthogonal to the optical axis. It is characterized by being set at an interval.

  According to the above configuration, when setting the three or more reflection directions by the micromirror array, first, by setting a predetermined offset angle with respect to the optical axis of the objective lens, the reflection direction is changed from the objective lens to the microscopic direction. It can be outside the optical path to the mirror array, and the scanning direction of the micromirror is perpendicular to the optical axis.

  Therefore, by attaching the micromirror to the drive unit that drives the micromirror with the predetermined offset angle, the drive unit can be used for scanning only one axis, and the drive unit can be used. Can be simplified.

  The two-dimensional colorimetric apparatus of the present invention further includes a colorimetric control unit that controls the scanning of the micromirror array and the measurement operation of the two-dimensional array sensor, and the colorimetric control unit includes the micromirror array as described above. Preliminary measurement is performed by sequentially scanning with a predetermined light integration time, and the amount of light received by each sensor element is substantially equal from the light intensity measured by each sensor element of each two-dimensional sensor unit in the preliminary measurement. The main measurement is performed by adjusting the scanning time of each micromirror array, and the calculation unit performs color determination from a value obtained by dividing the measurement result by the adjusted scanning time.

  According to the above configuration, in a two-dimensional measurement object such as the display, the luminance at each point may vary depending on the display image. Therefore, a colorimetry control unit is provided for controlling the scanning of the micromirror array and the measurement operation of the two-dimensional array sensor, and the colorimetry control unit sequentially scans each micromirror array with the predetermined integration time of the light. As a result of the preliminary measurement, the scanning time (light integration time) of the corresponding micromirror is increased for the sensor element of the dark spot, and the sensor element of the bright spot is shortened. Perform this measurement with the same amount of received light. After the measurement, the measurement result is divided by the adjusted scanning time by the calculation unit to correct the adjustment, and color determination is performed from the corrected value.

  Therefore, even if there is a variation in luminance at each point of the measurement object, measurement can be performed with substantially the same S / N.

  As described above, the two-dimensional colorimetric apparatus of the present invention is used as a display inspection apparatus or the like, and sequentially scans each point in a two-dimensional measurement object with a predetermined light integration time. In a stimulus value direct-reading type two-dimensional colorimetric apparatus for measuring color, light incident through an objective lens is two-dimensionally arranged from a plurality of micromirrors, and is reflected from the objective lens by a micromirror array composed of DMD, MEMS, or the like. Outside the optical path, three or more different directions are sequentially scanned and reflected (deflected), and the intensity of the reflected (deflected) light is measured outside the optical path from the objective lens to the micromirror array. Measurement is performed by a two-dimensional sensor unit arranged in each of the three or more reflection directions of the mirror array. To calculate the color.

  Therefore, when measuring the color of each point in the two-dimensional measurement object, the respective points are sequentially scanned by a minute displacement of the micromirror array made of DMD, MEMS, etc. The size can be reduced and the measurement (scanning) time can be shortened.

[Embodiment 1]
FIG. 1 is a perspective view for explaining an optical system of a two-dimensional colorimetric apparatus 1 according to a first embodiment of the present invention, and FIG. 2 is an optical path diagram thereof. This two-dimensional colorimetric device 1 is used for inspection of a display and the like, and sequentially scans each point in the two-dimensional measurement object 2 to obtain respective chromaticities from the tristimulus values X, Y, and Z. x, y and the luminance Lv as required are measured. It should be noted that the two-dimensional colorimetric apparatus 1 captures an image of the measurement object 2 with the objective lens 3, and a plurality of micromirrors 4 a are two-dimensionally arranged at the focal position of the objective lens 3. That is, the micromirror array 4 is arranged. The micromirror array 4 adds three or more incident lights (in this embodiment, the objective lens 3 (incident) direction is added to three directions respectively corresponding to the tristimulus values X, Y, and Z. The two-dimensionally arranged reflected light can be sequentially scanned in different directions, and the reflected light is arranged outside the optical path from the objective lens 3 to the micromirror array 4 via the fixed mirror 5. The light enters the sensor unit 6.

  In the two-dimensional sensor unit 6, the reflected light from the micromirror array 4 enters the filters 7X, 7Y, and 7Z of the tristimulus values X, Y, and Z, and the stimulus values X, Y, and Z components. Is extracted and imaged at one imaging position by imaging lenses 8X, 8Y, and 8Z provided corresponding to the filters 7X, 7Y, and 7Z, and arranged at the one imaging position. The intensity of each stimulus value X, Y, Z component is measured by each sensor element of the two-dimensional array sensor 9. From the measured light intensity, the calculation unit 10 determines the chromaticity x, y and the luminance Lv at each point in the two-dimensional measurement object 2.

The method for obtaining the chromaticity x, y and luminance Lv is as follows. First, the filters 7X, 7Y, and 7Z are combined with the sensor elements of the two-dimensional array sensor 9 to obtain color matching functions x (λ), y (λ), and z (λ) defined by CIE1931. It is designed to have an approximate spectral response. The output of each sensor element input to the arithmetic unit 10 is signal amplified and analog / digital converted. The digital values X, Y, Z corresponding to the outputs of the filters 7X, 7Y, 7Z obtained here are the spectral radiance of a certain point of the measurement object 2 as S (λ), and the filters 7X of the sensor element. , 7Y, 7Z, where x ′ (λ), y ′ (λ), z ′ (λ)
X = ∫S (λ) · x ′ (λ) dλ (1-1)
Y = ∫S (λ) · y ′ (λ) dλ (1-2)
Z = ∫S (λ) · z ′ (λ) dλ (1-3)
Where λ is the wavelength. The wavelength range is the visible light wavelength region. The chromaticity x, y and the luminance Lv can be calculated by performing the following calculation using the obtained digital values X, Y, and Z.

x = X / (X + Y + Z) (2-1)
y = Y / (X + Y + Z) (2-2)
Lv = Y (2-3)
The micromirror array 4 is composed of DMD (Dgital Micromirror Device), MEMS (Micro Electro Mechanical Systems), and the like, and each micromirror 4a is individually applied with a reference numeral 4v when a voltage is applied by the scanning control circuit 11. Biaxial scanning (deflection) is possible in the tilt direction indicated by と and the pan direction indicated by reference numeral 4h. If no voltage is applied, the mirror surface is kept parallel, that is, perpendicular to the optical axis, and therefore incident light is reflected in the direction of the objective lens 3 (incident). The micromirror 4a has a predetermined correspondence relationship with each sensor element of the two-dimensional array sensor 9. For example, ten sensor elements are provided for one micromirror 4a. The resolution is determined by the coarse (small number of elements) of the resolution of the micromirror 4a and the resolution of the two-dimensional array sensor 9. In the above example, as shown in FIG. 2, the image of the measurement object 2 is once formed on the micromirror array 4 by the objective lens 3, but the microlens array is inserted after the objective lens 3, You may make it parallel light and not image-form.

  In the two-dimensional colorimetric apparatus 1 configured as described above, a colorimetric control unit 12 that controls the scanning of the micromirror array 4 and the measurement operation of the two-dimensional sensor unit 6 is provided. The unit 12 performs preliminary measurement by sequentially scanning each micromirror array 4 with a predetermined integration time of light, and the light intensity (the digital value X) measured by each sensor element of the two-dimensional array sensor 9 in the preliminary measurement. , Y, Z), and the actual measurement is performed by adjusting the scanning time of each micromirror array 4 so that the amount of light received by each sensor element becomes substantially equal.

  Specifically, the colorimetry control unit 12 first performs normal measurement, which will be described later, on the predetermined integration time (exposure time) of the light, that is, the micromirror 4a for each predetermined scanning time, in order to each filter 7X, 7Y, Turning to 7Z, intensity measurements of the respective stimulus values X, Y, and Z are performed, and the preliminary measurement for obtaining the luminance value Lv is performed one or more times by the calculation unit 10 from the measurement results. From the luminance value of each point in the two-dimensional measurement object 2 thus obtained or the average value thereof, the colorimetric control unit 12 then scans the corresponding micromirror scanning time ( The scanning time of each micromirror 4a is determined so that the light integration time) is long and the sensor elements at the bright spots are short, and are set in the scanning control circuit 11 in this measurement. When a plurality of sensor elements of the two-dimensional array sensor 9 correspond to one micromirror 4a, the scanning time corresponds to the average value or the maximum luminance value of the preliminary measurement result of each sensor element. It only has to be decided.

  In this measurement, the normal measurement is performed at a set scanning time, and the intensity of each stimulus value X, Y, Z component is sequentially measured using each filter 7X, 7Y, 7Z. Specifically, at the start of measurement, all the micromirrors 4a are scanning (deflecting) toward one of the filters 7X, 7Y, and 7Z (8Y in FIG. 2), and the set scanning time is set. After that, as shown in FIG. 3, only the mirror 4b, the scanning control circuit 11 sets the applied voltage to 0 as described above, switches the mirror surface in parallel, and reflects the incident light in the direction of the objective lens 3 (incident). To avoid going to the sensor element. When switching the reflection direction, there is a possibility that some micromirrors cross the optical path of other micromirrors and the reflected light may be incident on other filters or sensor elements. The movement is agile and seldom a problem.

  Thus, when the longest value of the set scanning time has elapsed and all the micromirrors 4a have returned to the objective lens 3 (incident) direction, the scanning control circuit 11 is indicated by reference numeral 4c in FIG. Then, all the micromirrors 4a are scanned toward the next filter 8Z. On the other hand, the scan time set in the scan control circuit 11 is input from the colorimetric control unit 12 to the calculation unit 10, and the calculation unit 10 receives all the stimulus values X as described above. After measuring the intensity of the Y, Z and Z components, the measurement result is divided by the scanning time adjusted as described above to correct the adjustment, and from the corrected value, the chromaticity x , Y and the luminance Lv as required. This makes it possible to perform the actual measurement by making the amount of received light from each point of the measurement object 2 such as a display equal, and even if the luminance of each point of the measurement object 2 varies, the S is substantially equal. Measurement can be performed at / N. Note that the operation of the main measurement may be repeated a plurality of times in order to increase the reliability of the measurement.

  As described above, in the two-dimensional colorimetric apparatus 1 according to the present embodiment, a plurality of micromirrors 4a are two-dimensionally arranged for light incident through the objective lens 2, and the micromirror array 4 made of DMD, MEMS, etc. Measurement is performed by the stimulus value direct-reading type two-dimensional sensor unit 6, and the calculation unit 10 calculates the chromaticity x, y at each point in the two-dimensional measurement object 2 from the measurement result. The mechanism can be miniaturized and the measurement (scanning) time can be shortened.

  Further, the stimulus value direct-reading type two-dimensional sensor unit 6 is individually associated with the filters 7X, 7Y, and 7Z corresponding to the three stimulus values X, Y, and Z components, and the filters 7X, 7Y, and 7Z. An imaging lens 8X, 8Y, 8Z that is provided and images the transmitted light from the filters 7X, 7Y, 7Z at a predetermined imaging position, and two-dimensionally arranged at the one imaging position. By including the array sensor 9, the two-dimensional array sensor 9 can be shared in a time-sharing manner, and three stimulus values X, Y, and Z can be measured.

  Such calibration of the two-dimensional colorimetric apparatus 1 can be performed in the same manner as the calibration of a tristimulus colorimeter capable of measuring an existing point (spot). That is, a tristimulus colorimeter capable of measuring a reference point is prepared as a light source for calibration, and the calibration corresponding to one pixel of one pixel of the two-dimensional array sensor 9 is provided for each of WRGB of the light source for calibration. Each point of the light source is measured with the reference tristimulus colorimeter to obtain tristimulus values X, Y, and Z, which are column vectors A ′ = (X ′, Y ′, Z ′). And Similarly, with the two-dimensional colorimetric device 1 of the present embodiment, the calibration light source is subjected to normal measurement for each of WRGB, and the column vector A = (X, Y, Z) of the measurement result is obtained. Then, a 3 × 3 matrix W that satisfies A ′ = WA is obtained, and the measurement result is subjected to matrix calibration with this matrix W as a correction coefficient in actual actual measurement.

[Embodiment 2]
FIG. 4 is a block diagram showing the overall configuration of the two-dimensional colorimetric apparatus 21 according to the second embodiment of the present invention. The two-dimensional color measuring device 21 is similar to the above-described two-dimensional color measuring device 1, and corresponding portions are denoted by the same reference numerals, and the description thereof is omitted. Each micromirror 4a of the micromirror array 4 described above is composed of DMD or MEMS elements capable of biaxial scanning (deflection) in the tilt direction 4v and the pan direction 4h. In the embodiment, the micromirror 24a of the micromirror array 24 is attached to a drive unit (not shown) that drives the micromirror 24a so as to have a predetermined offset angle θ with respect to the optical axis 3a of the objective lens 3 (FIG. 5). In this example, in the tilt direction), the drive unit that performs scanning (deflection) of only one axis is used.

  Therefore, in the two-dimensional sensor unit 26, the filters 7X, 7Y, and 7Z and the corresponding imaging lenses 8X, 8Y, and 8Z are in a panning direction (in a direction orthogonal to the optical axis 3a and scann by the one axis ( (One-dimensional direction) 4h are arranged with a space therebetween. With this configuration, the driving unit, the scanning control circuit 11 and the like in the micromirror array 24 can be simplified.

It is a perspective view for demonstrating the optical system of the two-dimensional colorimetric apparatus which concerns on the 1st Embodiment of this invention. FIG. 2 is an optical path diagram of the two-dimensional color measuring device. FIG. 5 is an optical path diagram for explaining a scanning (exposure) time adjustment operation of the two-dimensional colorimetric apparatus. It is a block diagram which shows the whole structure of the two-dimensional colorimetric apparatus which concerns on the 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,21 Two-dimensional colorimetry apparatus 2 Measuring object 3 Objective lens 4, 24 Micro mirror array 4a, 4b, 4c, 24a Micro mirror 5 Fixed mirror 6, 26 Two-dimensional sensor unit 7X, 7Y, 7Z Filter 8X, 8Y, 8Z imaging lens 9 two-dimensional array sensor 10 arithmetic unit 11 scanning control circuit 12 colorimetric control unit

Claims (4)

In a stimulus value direct reading type two-dimensional colorimetric device for measuring the color at each point in a two-dimensional measurement object,
A plurality of micromirrors arranged in a two-dimensional array, and a micromirror array capable of reflecting light incident through the objective lens by sequentially scanning in three or more different directions outside the optical path from the objective lens; ,
A two-dimensional sensor unit that receives light scanned in the three or more reflection directions of the micromirror array outside the optical path from the objective lens to the micromirror array;
A two-dimensional colorimetric apparatus comprising: a calculation unit that calculates a color at each point in the two-dimensional measurement object from light intensity measured by each sensor element of each two-dimensional sensor unit. The two-dimensional sensor unit is
A filter corresponding to each of the three stimulus values;
An imaging lens provided corresponding to each of the filters individually, and imaging the transmitted light from the filter at a predetermined imaging position;
The two-dimensional colorimetric apparatus according to claim 1, further comprising a two-dimensional array sensor arranged at the one image forming position.   The three or more directions are set on a plane having a predetermined offset angle with respect to the optical axis of the objective lens and spaced from each other in a direction orthogonal to the optical axis. Item 2. The two-dimensional colorimetric apparatus according to item 1. A colorimetric control unit that controls scanning of the micromirror array and a measurement operation of the two-dimensional sensor unit, and the colorimetric control unit sequentially scans each micromirror array with the predetermined integration time of light; In the preliminary measurement, the scanning time of each micromirror array is adjusted from the light intensity measured by each sensor element of each two-dimensional sensor unit so that the amount of light received by each sensor element is substantially equal. Make this measurement,
The two-dimensional colorimetric apparatus according to claim 1, wherein the calculation unit performs color determination from a value obtained by dividing a measurement result by the adjusted scanning time.

Images