CN103210294A - Optical characteristic measuring device and method - Google Patents

Abstract

The present invention rapidly and accurately measures the optical characteristic of an optical film having a large area. An optical film (12) to be measured is mounted on a surface illumination unit (14). Circularly polarized light is cast on the optical film (12) from the surface illumination unit (14). By the movement of the optical film (12) in an X direction, a measurement pixel (E) on the optical film (12) passes first to fourth image capture areas of a CCD camera in an image capturing unit (15) in sequence. The CCD camera captures an image of the measurement pixel (E) multiple times when the measurement pixel (E) passes each of the image capture areas. The result acquired by adding output values obtained by capturing the image multiple times is defined as the measured value in the image capture area. The Stokes parameter of the measurement pixel (E) is calculated from the measured values in the four image capture areas. The Stokes parameters of all measurement pixels (E) on the optical film (12) are acquired.

Description

Measurement instrument of optical characteristics and method

Technical field

The present invention relates to a kind of measurement instrument of optical characteristics and method that the polarized light property of blooming is measured.

Background technology

Use Polarizer, visual angle to revise the functional plastic resin film with various optical characteristics of film, anti-reflective film etc. (below be called " blooming ") in the liquid crystal indicator.Liquid crystal indicator utilizes birefringence (double refraction) characteristic that liquid crystal has and obtains contrast (contrast), thereby also must have the birefringent characteristic of regulation in the employed blooming.Birefringent characteristic in this blooming does not have at whole face under the situation of homogeneity, can produce uneven during the image of liquid crystal indicator shows.

Therefore, before blooming is assembled to liquid crystal indicator, need whether has desired birefringent characteristic to film and measure.The measurement of birefringent characteristic uses following various optical component to carry out: the light source that the blooming that becomes measuring object is shone measuring light, be received from the light-receiving device of the light that blooming sends, and in order to polarizer that the polarized light property of blooming etc. is measured or Polarizer etc.

For example, in the patent documentation 1, by at light source with (charge coupled device CCD) makes polarizer rotate and produce various polarized condition around optical axis between the camera as the charge-coupled image sensor of light-receiving device.And, utilize the CCD camera that the image of different polarized condition is made a video recording, change according to the brightness value by each pixel of the group of pictures that obtains of shooting each pixel is calculated birefringent characteristic.And, in the patent documentation 2, disclosed a kind of method of on prescribed direction, the birefringent characteristic of the blooming in the conveyance being carried out online (on line) measurement.And, disclosed in the patent documentation 3 as lower device: while when film being moved measure, consider the translational speed of the visual field size of CCD camera and blooming and repeat shooting, the birefringence of large-area blooming is distributed measure by this.

[prior art document]

[patent documentation]

[patent documentation 1] Jap.P. spy opens the 2009-229279 communique

[patent documentation 2] Japanese patent laid-open 5-346397 communique

[patent documentation 3] Jap.P. spy opens the 2007-263593 communique

Summary of the invention

In recent years, because liquid crystal indicator maximizes, also use and have large-area blooming so be assembled in wherein blooming.With this, seek device or the method that to measure the birefringent characteristic with large-area blooming.For example, need to carry out the inspection of blooming of the size of A3 degree in the liquid crystal indicator about 20 inches.

With regard to this point, in the prior art shown in above-mentioned patent documentation 1～patent documentation 3, based on following reason, can't be to the birefringent characteristic of large-area blooming rapidly and the problem of measuring accurately and exist.Under the situation of patent documentation 1, it is desirable to use telecentric lens (telecentric lens) to be used as imaging lens system, Yi Bian but the visual field of lens is about 5cm at most, thereby can't check the A3 size with a visual field.

Therefore, need blooming be divided into a plurality of measurement zones corresponding to the visual field of CCD camera, and carry out birefringence measurement at this each measurement zone, carry out whole inspection by this.At this moment, in each measurement zone, while must the angle rotation that make polarizer under the static state of CCD camera be made a video recording for the polarized condition of blooming is measured.Therefore, in the measurement zone of regulation, repeat shooting (static) → towards another measurement zone move CCD camera → in another measurement zone, make a video recording (static) → ..., thereby exist measurement how also not make progress and time-consuming problem.

And, in the patent documentation 2, with a bit measuring along the conveyance direction on the blooming.Because there not being the rotation of special polarizer, so need not to make camera or film to stop just can to measure.To this, for a point measurement is expanded to planar survey, and consider this measurement mechanism is arranged at the Width of blooming.Yet, for example be under 1mm square the situation, if the Width of this measurement mechanism at the blooming of A3 size disposed, all to need 294 table apparatus, thereby we can say and can't realize at the measurement space resolution of the measurement mechanism shown in the patent documentation 2.The term of " measurement space resolution " as used herein refers to the size of 1 measurement point on the measuring object, then becomes the Pixel Dimensions of this image the most at last during the distributed image of measurement result.

And, in the patent documentation 3 in the employed CCD camera, the required Polarizer of measurement under the polarized condition of blooming is being set at each photo detector, thereby is need not as making the polarizer rotation as the patent documentation 1 when each shooting.Yet the problem of the noise (noise) that the CCD camera has in this patent documentation 3 can't solve, thereby can't carry out high-precision measurement.

In the patent documentation 3, the measurement of 1 visual field size is to carry out according to 1 image that 1 shooting by the CCD camera obtains.In the CCD camera, even if when under identical conditions, making a video recording continuously, the deviation of the brightness that causes by the noise because of CCD, change that also can the generation value in each output valve that obtains.That is the reproduction of measuring in the patent documentation 3 must be insufficient.

Among the present invention, using the bidimensional image sensor to come having under the situation about measuring than the polarized light property of the more large-area blooming in the shooting visual field of this bidimensional image sensor, because no longer including, the shooting of carrying out a plurality of polarized condition makes image sensor static necessity on blooming, and for the repeatedly shooting of the identical image of carrying out in order to improve measuring accuracy, also need not to make image sensor to stop just can to carry out.Therefore, the object of the present invention is to provide a kind of rapidly and have polarized light property measurement mechanism and a method of high measurement accuracy.

Measurement instrument of optical characteristics of the present invention is characterised in that and comprises: light projector mechanism, measuring object is shone specific polarizing illumination; Image mechanism is arranged wavelength plate in the alignment of the 1st direction, realize at least 4 kinds of polarized light properties in the 1st direction, and comprise image sensor that this image sensor is divided into the shooting district to individually making a video recording by the light of above-mentioned wavelength plate; And scanning mechanism, make image mechanism with respect to measuring object and relatively mobile in above-mentioned the 1st direction; And be accompanied by relatively moving of the image mechanism that undertaken by above-mentioned scanning mechanism, to measure pixel at each and carry out addition in each shooting district, repeatedly the make a video recording output valve that obtains of pixel of respectively measuring of measuring object, and calculate the measured value in this shooting district, and calculate stoke scholar's parameter (Stokes Parameter) that each measures the light of pixel according to the measured value of collecting from each shooting district.Be preferably the imaging apparatus that above-mentioned image sensor utilization comprises a plurality of pixels and make a video recording, and when shooting, at each with a plurality of pixels of adjacency in addition be combined into combining unit and export an output valve.Being preferably before measuring with the combining unit is that unit obtains polarisation transfer matrix (transfer matrix), this polarisation transfer matrix is represented to use above-mentioned polarisation transfer matrix and the output valve of exporting from above-mentioned each shooting district to obtain stoke scholar's parameter of measuring object from measuring light that object the sends relation with the output valve of each shooting district output of self imaging sensor.

As shown in Figure 1, because in the measurement as the blooming 12 of measuring object, the measurement space resolution being stipulated as known condition, the set of the measurement result of the Microcell that so The ultimate results is each to form blooming 12 with the big or small sectionalization of measurement space resolution, that is the face distributed intelligence of optical characteristics.On the blooming 12 as measuring object, regard the existence district that imagination ground sectionalization forms with the measurement space resolution as,, be called " measuring pixel E " later on to being referred to as in this each district.

Being preferably above-mentioned image sensor is that unit exports the output valve that obtains by shooting with the combining unit.So-called " combining unit " is the image unit of the image sensor of adjacency to be summed up the regulation number in length and breadth and as a big unit (combining unit) herein, the output valve of this unit be made as all image units that will comprise in the combining unit the output valve equalization and value.This each combining unit is referred to as, is called " combining unit CP " later on.

Be that the reason that unit makes a video recording is as follows with combining unit CP so.The deviation of the output valve the when curve of Fig. 2 represents to use the CCD camera of 12 bits output to be used as image sensor.This curve is that the deviation range mapping is formed, this deviation range is the bright relatively light (output valve is near 3740 light) of combining unit input that the pixel that combines specified quantity is formed, and will deduct the minimum value gained by maximal value in all output valves after carrying out merely measuring for 256 times.In this curve, the longitudinal axis is represented the deviation of the output valve of CCD camera, and transverse axis is represented the combining unit number, this combining unit numerical table show pixel in conjunction with number.Herein, for example, the combining unit number is that 4 combining unit has vertical 2 pixels, horizontal 2 pixels.Moreover among Fig. 2, bullet is represented the deviation range (measurement result) of the output valve of CCD camera, and dotted line is represented the curve of approximation that obtains according to bullet.According to this result as can be known, roughly negative 1/2 power that is attached to noise in the output of CCD camera and combining unit number is proportional, and has the character of random noise (random noise).

Shown in this curve, whenever with Unit 1, Unit 4, Unit 9, Unit 16 ... and when increasing unit size (combining unit number), the deviation of the output valve of CCD camera reduces.Therefore, if the combining unit number is not increased to make a video recording to a certain extent, then the deviation of the output valve of CCD camera is big, thereby only otherwise increase shooting number and averaging etc., just can't measure accurately.In addition, the CCD that uses in order to obtain this curve is 1/1.8 inch, 2,000,000 pixels, and image unit to be of a size of 4.4 μ m square.

The number that constitutes the pixel of combining unit CP is preferably as 1,4,9 ... as from 1 the beginning N ²The number of the progression of (N is natural number), maximal value are made as the measurement space resolution (that is size of measurement pixel E) of the measuring object of imaging on above-mentioned image sensor and are the number of the size of combining unit.

Fig. 3 represents image pickup part 15.Expression herein uses CCD to be used as the example of image sensor, and (complementary metal oxide semiconductor CMOS) is used as image sensor but also can use complementary metal oxide semiconductor.And the example of 4 wavelength plates is used in expression with per 1 wavelength plate, a kind of polarized light property of realization.The quantity of wavelength plate also is not limited only to as described later 4 kinds.The structure of image pickup part 15 comprises camera case 40, CCD camera 41, telecentric lens 42, CCD camera rotating mechanism the 43, the 1st wavelength plate～the 4th wavelength plate 45～48 and Polarizer 49.Camera case 40 has roughly rectangular shape, and in order to opening 40a(that the 1st wavelength plate～the 4th wavelength plate 45～48 and Polarizer 49 are installed with reference to Fig. 4) be formed with 1.CCD camera 41, telecentric lens 42 and CCD camera rotating mechanism 43 are being set in this camera case 40.Moreover CCD camera rotating mechanism 43 is intended to make 1 direction of the two-dimensional arrangements of combining unit to adjust with the direction of scanning of scanning mechanism is consistent.Moreover the arrow X among Fig. 3 represents the direction that relatively moves (which of measuring object or image pickup part move all can) of measuring object.

Telecentric lens 42 uses both sides telecentric lens or object side telecentric lens.Telecentric lens 42 be picture with measuring object on CCD with the size of the lens multiplying power that multiply by these lens 42 and imaging (about multiplying power, use be 1 times～1/3 times multiplying power).Because of the ability of the dark depth of focus of telecentric lens and the seizure light beam parallel with optical axis, the light by each wavelength plate arrives image sensor and can not mix, and forms individual other district corresponding with each wavelength plate.After, each district that can receive on the CCD light beam by this each wavelength plate, that essence is divided by wavelength plate is referred to as " shooting district ".

Utilize Fig. 4 to illustrate that the some measurement pixel E on the blooming 12 are measured by image pickup part 15 in which way by the 1st wavelength plate～the 4th wavelength plate 45～48 backs.

Moreover, among Fig. 4, understand easily in order to make explanation, do not comprise dwindling or amplification effect and then do not comprise the inversion imaging effect of telecentric lens 42 among the figure, but with 1 on the blooming 12 with on CCD55 to wait doubly upright imaging mode to describe.

At first, in the time of on the blooming 12 certain is measured pixel E enters image pickup part 15 by scanning mechanism the visual field, measure in the block that light that pixel E sends enters the 1st wavelength plate 45 at first certainly and this block of crosscut after a period of time.The 1st wavelength plate 45 is under the effect of telecentric lens 42, imaging in the shooting district 50 of correspondence on CCD55, thereby in the process of the block of measuring pixel E crosscut the 1st wavelength plate 45, measure the block in the picture crosscut shooting district 50 of pixel E, repeatedly make a video recording corresponding to the moving of certain distance of measuring pixel E.Similarly, the imaging in 51～shooting district 53, shooting district of the 2nd wavelength plate～the 4th wavelength plate 46～48 is measured pixel E and is also repeatedly made a video recording herein.

In advance the combining unit CR with CCD is that unit obtains the polarisation transfer matrix, and this polarisation transfer matrix represents to be incident to the relation of the output valve that stoke scholar's parameter and the self imaging sensor of the light of image mechanism export.

The output valve about the CCD that measures pixel E that is obtained by shooting, the matrix product of the polarisation transfer matrix that has for stoke scholar's parameter of measuring the light that pixel E sends certainly and the combining unit that this measurement pixel E is made a video recording.

By shooting obtain about each output valve of the CCD that measures pixel E at each shooting district and addition, and extract as the measured value in this shooting district.The matrix of the polarisation transfer matrix of employed combining unit CR and also distinguish at each shooting and carry out when simultaneously, measuring the shooting of pixel E.Like this, only obtain according to the quantity (or quantity of the kind of the polarized condition of realization) in shooting district with stoke scholar's parameter of light and the relational expression of polarisation transfer matrix about the measured value of measuring pixel E.Because measured value has the quantity in shooting district to be 4 kinds, so the stoke scholar's parameter that can calculate thus.This step is to measure pixel E at each to carry out, and can calculate the face distributed intelligence of stoke scholar's parameter of measuring object by this.

Be preferably that above-mentioned image sensor is striden and 2 combining units of adjacency and the measurement pixel of regulation is made a video recording.The output valve that is preferably the measurement pixel of afore mentioned rules comprises: will in the combining unit output mean value of the shared ratio of the pixel of measurement pixel after making a video recording of regulation and this pixel be multiplied each other and value, and the multiply each other value of gained of the output mean value of the shared ratio of the pixel after in another combining unit the measurement pixel of stipulating being made a video recording and this pixel.

Being preferably above-mentioned travel mechanism makes in measuring object or the image mechanism one of them mobile in the 1st direction, and when the shooting of the 1st direction of the measuring object that is undertaken by above-mentioned image mechanism finished, making in measuring object or the image mechanism one of them had been that right angle and 2nd direction parallel with measuring object are mobile with the 1st direction.

Being preferably and making in measuring object or the image mechanism one of them in above-mentioned travel mechanism is being under the mobile situation of right angle and the 2nd direction parallel with measuring object with the 1st direction, keeping the position relation on the 2nd direction of image mechanism and light projector mechanism and moving it, that is move it in the mode that position relation does not change, and the polarisation range of exposures of light projector mechanism is contracted to the degree of the field range of shining the 2nd direction of image mechanism.

The quantity that is preferably the kind of the polarisation of realizing by above-mentioned wavelength plate is 4 to 40.Being preferably above-mentioned wavelength plate, to have with slow phasor be the slow phase effect that any wavelength plate is identical in 70 ° to 170 ° or 190 ° to 290 °.

Optical characteristic measurement method of the present invention is characterised in that: use image mechanism, this image mechanism is arranged wavelength plate in the alignment of the 1st direction, realize at least 4 kinds of polarized light properties in the 1st direction, and comprise image sensor, this image sensor is divided into the shooting district to individually making a video recording by the light of above-mentioned wavelength plate, make image mechanism with respect to measuring object and relatively mobile in above-mentioned the 1st direction, measuring object respectively measured the output valve addition that pixel is repeatedly made a video recording and obtained in each shooting district, and measure the measured value that pixel is calculated this shooting district at each, and calculate stoke scholar's parameter of measuring the light that object sends certainly according to the measured value of similarly collecting from each shooting district and at each measurement pixel.

[effect of invention]

According to the present invention, because using following image mechanism, namely, at least 4 kinds of wavelength plates that polarized light property is different are arranged in the alignment of the 1st direction, and comprise 4 shooting districts to the wavelength plate of individually making a video recording by each light of above-mentioned wavelength plate, so be accompanied by measuring object with respect to the movement towards the 1st direction of image mechanism, the polarisation that pixel carries out in the above-mentioned process that relatively moves more than 4 kinds continuously of respectively measuring on the measuring object is measured shooting.And then, in a shooting district, each is measured pixel and repeatedly makes a video recording for different measurement pixels, and measure the polarisation transfer matrix of measurement pixel separately in advance, therefore realize the essence average treatment with the repeatedly measurement of same measurement and can improve signal/noise (signal/noise, S/N) ratio.So, Yi Bian image mechanism is not relatively moved with respect to measuring object with stopping, Yi Bian the polarized condition of reaching simultaneously more than 4 kinds is measured and repeatedly shooting.Behind the mobile end towards the 1st direction (namely measure and finish) of measuring object, make the shooting object mobile in the 2nd direction with the degree that is equivalent to field range, can enlarge measurement face by this, thereby can repeatedly carry out towards the dollying of the 1st direction and can carry out whole measurement of measuring object towards the movement of the 2nd direction.Because carrying out the measurement of the polarized condition more than 4 kinds, so can determine to measure stoke scholar's parameter.By stoke scholar's parameter of light source is compared with measuring stoke scholar's parameter, and can calculate the polarized light property of measuring object.

So, according to the present invention, can measure rapidly and accurately the polarized light property of large-area blooming.For example, be that 1mm is square in spatial resolution, axle measurement of bearing precision is under 0.1 ° the condition, to need about 10 minutes in the previous method, and the measurement of carrying out about 2 minutes halfs among the present invention gets final product.That is, according to the present invention, compare with previous method, can reach about 4 times high speed.

Description of drawings

Fig. 1 is that explanation is as the key diagram of the measurement pixel of the blooming of sample.

Fig. 2 is the curve of relation of the deviation (output valve is near 3740/4096 data of high brightness in the camera of 12 bits) of the output valve of expression combining unit number and CDD camera.

Fig. 3 is the skeleton diagram of image pickup part.

Fig. 4 distinguishes measuring the key diagram that pixel E makes a video recording in the 1st shooting district～the 4 shooting of CCD camera in order to explanation.

Fig. 5 is the skeleton diagram of measurement instrument of optical characteristics of the present invention.

Fig. 6 is the process flow diagram of expression effect of the present invention.

Fig. 7 is the key diagram of the light projector pixel of explanation face Lighting Division.

Fig. 8 is the light that uses in order to obtain the polarisation transfer matrix of expression and the skeleton diagram of image pickup part.

Fig. 9 is the skeleton diagram of expression correcting measuring and the two-dimensional arrangements structure with 1 key element of the storage area of employed XY address in the measurement.

Figure 10 (A), Figure 10 (B), Figure 10 (C) come measuring the key diagram that pixel E1 makes a video recording by each combining unit in the 1st shooting district of CCD camera in order to explanation.

Figure 11 (A), Figure 11 (B), Figure 11 (C) come measuring the key diagram that pixel E1 makes a video recording by each combining unit in～the 4 shooting district, the 2nd shooting district of CCD camera in order to explanation.

Figure 12 will be stored in the key diagram of the 1st storage part～the 4th storage part E11～En4 by the output valve that the shooting of measuring pixel E1～measurement pixel En obtains in order to explanation.

Figure 13 comes measuring the key diagram of the situation that pixel E1 makes a video recording with the ratio of 7:3 in order to description taken in conjunction unit CP11 and CP12.

Figure 14 (A)～Figure 14 (E) measures pixel E1 by the key diagram of combining unit CP11～CP15 shooting 11 times in order to explanation.

Figure 15 comes measuring the key diagram of the situation that pixel E1 makes a video recording with the ratio of 5:5 in order to description taken in conjunction unit CP11 and CP12.

Figure 16 is the curve of the relation of the expression slow phasor of employed wavelength plate and error of calculation amount.

Figure 17 is the table of the relation of the expression slow phasor of employed wavelength plate and error of calculation amount.

Figure 18 is the skeleton diagram of image pickup part that expression the 1st wavelength plate～the 4th wavelength plate is arranged on the dead ahead of CCD camera.

Figure 19 is the skeleton diagram of measurement mechanism that the Lighting Division refinement is made.

Figure 20 is the skeleton diagram that expression comprises the measurement mechanism of 2 CCD cameras.

Embodiment

As shown in Figure 5, the measurement instrument of optical characteristics 10 of the present invention blooming 12 that will have a birefringent characteristic of regulation is measured as measuring object.In the measurement instrument of optical characteristics 10, mounting the blooming 12 of measuring object on the face Lighting Division 14 that is installed in sample platform 13.And, the illumination light of the rotatory polarization that utilization is sent from face Lighting Division 14 (circularly polarized light) is come light optics film 12, utilizes 15 pairs of light that send from this blooming 12 of image pickup part to make a video recording while sample platform 13 is moved at directions X.And computer 16 carries out various parsings according to the output valve that is obtained by image pickup part 15, obtains the optical characteristics of blooming 12 by this.In addition, also can use elliptical polarized light as polarizing illumination.

Sample platform 13 is by directions X travel mechanism 20, can be along 2 track 22a, track 22b on the base station 22 and mobile at directions X.And directions X travel mechanism 20 comprises the servo motor that drives according to the driving pulse from 24 outputs of X motor driver.

Similarly, image pickup part 15 is installed in and is arranged on the arm 31 of supporting platform 30.Arm 31 can move in the Y-direction with the directions X quadrature by Y-direction travel mechanism 33, and can be mobile with the Z direction of directions X or Y-direction quadrature by Z direction travel mechanism 34.So, mobile in Y-direction or Z direction by arm 31, and image pickup part 15 also can be mobile in Y-direction or Z direction.Moreover the purpose that moves towards the Z direction is in order to carry out the focus adjustment of image pickup part 15.Y-direction travel mechanism 33 drives according to the driving pulse of exporting from Y motor driver (not shown).

Be sent to respectively in X impulse meter 26 and the Y impulse meter (not shown) from the driving pulse of X motor driver 24 with the Y motor driver.Each impulse meter is counted received driving pulse.Value by the impulse meter counting is sent to computer 16.Store the amount of movement of sample platform 13 of each pulse and the amount of movement of image pickup part 15 in the computer 16, therefore can be positioned at which position on the sample platform 13 according to the visual field that the count value of two impulse meters is grasped image pickup part 15.

Then, the process flow diagram according to Fig. 6 comes effect of the present invention is described.At first, what carry out at first is measure to prepare, and herein, is the polarisation transfer matrix that unit specifies image pickup part 15 with the combining unit CP of CCD camera 41.This operation is only carried out once as initial setting.The polarisation transfer matrix of obtaining is stored in the computer 16, uses the above-mentioned polarisation transfer matrix of obtaining later at initial setting.

What measurement was carried out after preparing is correcting measuring.Spread all over whole of face Lighting Division 14 and measure stoke scholar's parameter (being designated as the S parameter later on) of the light that sends from face Lighting Division 14 with the unit of measuring resolution herein.

In the face Lighting Division 14 as light projector mechanism, regarding as shown in Figure 7 imaginary of existence as is unit and this each district is referred to as in the district of sectionalization to measure resolution, is called " light projector pixel L " later on.Thus, correcting measuring is the step of obtaining the S parameter with light projector pixel unit L.

Then need not to carry out correcting measuring as long as no light source changes, but comparatively ideal be roughly when one day initial measurement, to carry out.

What carry out after the correcting measuring is actual measurement,, places bloomings 12 at face Lighting Division 14 herein, spreads all over whole of blooming 12 and measure resolution (that is measuring object E) with measuring object and measure S parameter by the light of blooming 12 for unit.

At last, the S parameter of the S parameter of actual measurement gained and Lighting Division is compared and calculate the birefringent characteristic of measuring object.Herein importantly, by making the position of respectively measuring pixel E in the actual measurement and the position consistency of each the light projector pixel L in the correcting measuring, and the counter that in measurement, uses the measuring object platform to have.Judge according to the currency of counter each combining unit of camera captures which position of measuring object platform, thereby can the output valve of each combining unit of gained positively be split up into each light projector pixel L or respectively measure pixel E when measure.

Below, measure preparation process certainly and begin to be described in detail.Measuring preparation process is following steps: before actual measurement, specify the polarisation transfer matrix of each combining unit of employed CCD camera in the image pickup part 15 of this device.Can self be assembled in employed measuring mechanism in this appointment in this device, also can separate with this device and carry out externally that the polarisation transfer matrix is measured and use universal serial bus (Universal Serial Bus, USB) mechanism of storer etc. and only data being deposited in the computer 16.

Be that the reason that unit obtains the polarisation transfer matrix of image pickup part 15 is with the combining unit of CCD camera 41: thus the high representative measured value of a reliability of this wavelength plate will be obtained by the measured value equalization that a plurality of measurement pixel E that are arranged in same wavelength plate block are obtained.Though be the light that has passed through same wavelength plate block, the measured value that records owing to the different measurement pixel of the different part that is to use wavelength plate, Polarizer, telecentric lens, CCD, thereby can't handle in the same manner.This is because there is the deviation (locality (locality)) of local polarisation transmission characteristic respectively.Yet, if obtain the polarisation transfer matrix at each combining unit unit in advance, can revise the influence of locality and the representative measured value that reliability is high is summed up as one according to a plurality of measured values.

The polarisation transfer matrix is the matrix that expression is incident to S parameter with the relation of the output valve of exporting from CCD camera 41 of image pickup part 15 light.This polarisation transfer matrix can determine according to the long-pending of mueller matrices (Mueller matrix) (making Metzler matrix with postscript) of the optical component that forms image pickup part 15 etc.Setting up related Metzler matrix with certain combining unit on the CCD is that following matrix multiple is obtained: be incident to any light beam in wavelength plate 45～wavelength plate 48 that the light beam of this combining unit passes through by Metzler matrix partly, the light beam of Polarizer 49 is by the Metzler matrix of part, the light beam of telecentric lens is by the Metzler matrix of part, and the Metzler matrix of this combining unit of CCD.The general type of this Metzler matrix of expression in [several 1].* mark and later calculating are irrelevant, thereby are the key elements that need not appointment.

[several 1]

Only extract the 1st row of this Metzler matrix, if with M ₁₁The key element standardization then becomes [several 2].Be polarisation transfer matrix in this combining unit with this defined matrix.

[several 2]

${\mathrm{<figure-callout\; id="11"\; label="M"\; filenames="HDA00003181292200121.png"\; state="\{\{state\}\}">M</figure-callout>}}_{11}\&CenterDot;\left|\begin{array}{cccc}1& {\mathrm{<figure-callout\; id="12"\; label="M"\; filenames="HDA00003181292200011.png,HDA00003181292200022.png"\; state="\{\{state\}\}">M</figure-callout>}}_{12}/M_{11}& {\mathrm{<figure-callout\; id="13"\; label="M"\; filenames="HDA00003181292200121.png"\; state="\{\{state\}\}">M</figure-callout>}}_{13}/M_{11}& {\mathrm{<figure-callout\; id="14"\; label="M"\; filenames="HDA00003181292200022.png,HDA00003181292200042.png"\; state="\{\{state\}\}">M</figure-callout>}}_{14}/{\mathrm{<figure-callout\; id="11"\; label="M"\; filenames="HDA00003181292200121.png"\; state="\{\{state\}\}">M</figure-callout>}}_{11}\end{array}\right|$

And, again by the mark M in close relations with Metzler matrix ₁₂, M ₁₃, M ₁₄Replace M ₁₂/ M ₁₁, M ₁₃/ M ₁₁, M ₁₄/ M ₁₁, by COEFFICIENT K displacement M ₁₁, and obtain [several 3].

[several 3]

$K\&CenterDot;\left|\begin{array}{cccc}1& M_{12}& M_{13}& {\mathrm{<figure-callout\; id="14"\; label="M"\; filenames="HDA00003181292200022.png,HDA00003181292200042.png"\; state="\{\{state\}\}">M</figure-callout>}}_{14}\end{array}\right|$

With the matrix of the form shown in [several 3] the general mark as the polarisation transfer matrix in the performance combining unit.Herein, K is the scale-up factor of polarisation transfer matrix, and also comprises shading (shading) effect (deviation of the quantum efficiency of each combining unit of CCD camera 41 (quantum efficiency) or gain (gain) coefficient) of CCD camera in this value.

In measuring preparation process, as shown in Figure 8, using the S parameter is known light 70, in all combining units of image pickup part 15 each and individually obtain the polarisation transfer matrix.Herein, the S parameter is that known light 70 is that the directional light from collimated monochromatic ligth source 72 obtains by Polarizer PL1 and 1/4 wavelength plate QWP1 in the benchmark light projector 71 by making.Polarizer PL1 fixes in the orientation and is made as 0 ° as if the reference direction with the orientation in the image pickup part 15, then passes through axle with 0 ° of configuration.1/4 wavelength plate QWP1 comprises the continuous rotating mechanism (omitting diagram) that motor drives, and makes this 1/4 wavelength plate QWP1 rotation and using continuously in the measurement of polarisation transfer matrix.The slow phasor of the reality of employed wavelength plate QWP1 is known with the axle orientation, and the leading phase shaft orientation also is 0 ° with the reference bearing in the image pickup part 15 and defines.

Known light 70 is near the light beam of optical axis center of benchmark light projector 71.In measuring for 1 time 1 polarisation transfer matrix of combining unit is measured.The optical axis center of the light beam of benchmark light projector 71 is in the mode at the center of the combining unit that becomes measuring object by image pickup part 15, uses the 71a of XY travel mechanism of benchmark light projector 71 and makes benchmark light projector 71 relative with image pickup part 15.Finish if the polarisation transfer matrix of 1 combining unit is measured, the polarisation transfer matrix that then uses the 71a of XY travel mechanism to carry out adjacent measurement pixel is measured.So, the polarisation transfer matrix of all combining units of image pickup part 15 is measured.

Herein, the known S parameter with light 70 is made as | P ₀P ₁P ₂P ₃| ^T, the measuring method of the polarisation transfer matrix of some combining units is described.

The signal value output of this combining unit with measure in the S parameter of employed light 70, when the polarisation transfer matrix of this combining unit is recorded and narrated with [several 3], have the relation of [several 4].

[several 4]

Output valve=K{1P ₀+ M ₁₂P ₁+ M ₁₃P ₂+ M ₁₄P ₃}

If the constant of use QWP1 is described in detail each key element of the S parameter of light 70, then represented by [several 5].

[several 5]

$K^{\&prime;}\&CenterDot;\left|\begin{array}{c}1\\ {\mathrm{<figure-callout\; id="2"\; label="C"\; filenames="HDA00003181292200051.png"\; state="\{\{state\}\}">C</figure-callout>}}^2+{\mathrm{<figure-callout\; id="2"\; label="S"\; filenames="HDA00003181292200051.png"\; state="\{\{state\}\}">S</figure-callout>}}^2\&CenterDot;\cos \mathrm{\&epsiv;}\\ C\&CenterDot;S\&CenterDot;(1-\cos \mathrm{\&epsiv;})\\ S\&CenterDot;\sin \mathrm{\&epsiv;}\end{array}\right|$

, the orientation of QWP1 is made as γ herein, phase differential is made as ε, C=cos2 γ, S=sin2 γ.

K' is in order to obtain the coefficient of coupling with the output valve of the CCD camera 41 of reality, and is the real number that determines in this measurement.

According to more than, P ₀, P ₁, P ₂, P ₃Become following [several 6].

[several 6]

P ₀=K'

P ₁=K'·(C ²+S ²·cosε)=1/2·K'·(1+cosε)+1/2·K'·(1-cosε)·cos4γ

P ₂=K'·C·S·(1-cosε)=1/2·K'·(1-cosε)·sin4γ

P ₃=K'·S·sinε=K'sinε·sin2γ

[several 6] substitution [several 4] is obtained [several 7].

[several 7]

Output valve=KK'{1+M ₁₂1/2 (1+COS ε)

+M ₁₂·1/2·(1-cosε)·cos4γ

+M ₁₃·1/2·(1-cosε)·sin4γ

+M ₁₄·sin2γ·sinε}

About these [several 7], (Discrete Fourier Transformation DFT), then shown in [several 8], obtains 4 relational expressions of the output valve of expression flip-flop and following frequency content to carry out the discrete Fourier conversion as if the orientation γ with QWP1.Herein, Fdc represents the amplitude through measuring of flip-flop, and Fcos4 represents the amplitude through measuring of cos4 γ composition, and Fsin4 represents the amplitude through measuring of sin4 γ composition, and Fsin2 represents the amplitude through measuring of sin2 γ composition.

[several 8]

Fdc=K·K'·(1+Mn ₁₂·1/2·(1+cosε))

Fcos4γ=K·k'·1/2·(1-cosε)·Mn ₁₂

Fsin4γ=K·K'·1/2·(1-cosε)·Mn ₁₃

Fsin2γ=K·K'·sinε·Mn ₁₄

It should be noted that the numerical value rising that dark current (even if be that zero CCD also exports certain value for the light quantity) part of CCD causes among the Fdc herein.When this numerical value is made as BG, in [several 8] from value that Fdc deducts the BG gained flip-flop for using in should calculating afterwards, 4 formulas of [several 8] are corrected for [several 9].Moreover BG can specify by the light that interdicts the CCD camera fully, can obtain this value in advance.

[several 9]

Fdc-BG=K·K'·(1+M ₁₂·1/2·(1+cosε))-(1)

Fcos4=K·K'·1/2·(1-cosε)·M ₁₂-(2)

Fsin4=K·K'·1/2·(1-cosε)·M ₁₃-(3)

Fsin2=K·K′·sinε·M ₁₄-(4)

In 4 formulas shown in [several 9], unknown number is KK', M ₁₂, M ₁₃, M ₁₄These 4, so evaluation.For example, can specify M according to (1) ÷ (2) ₁₂, can specify KK' then, can specify M afterwards ₁₃, M ₁₄

So, can specify all key elements of polarisation transfer matrix of 1 combining unit and the value of K.K '.By in all combining unit CP, repeating this calculating, and can specify polarisation transfer matrix among all combining unit CP of image pickup part 15 and the value of K.K '.In the value of K.K', K is because of the different value of each combining unit, and K ' is the value relevant with employed light intensity in this measurement preparation and regards as fixing during this measurement.Thus, can be used as relative signal intensity ratio between each combining unit in the measurement (correcting measuring, actual measurement) afterwards of the value of the K.K ' of appointment herein.And then in the measurement afterwards, even if light intensity is different with this measurement of measure preparing, also can use this value to be used as relative signal intensity ratio between each combining unit.

Herein, each key element of the polarisation transfer matrix in each combining unit CP of appointment is stored in the computer 16 in advance.At this moment, in the explanation afterwards of the value of the K.K ' of appointment herein with the reference by the K mark again.

So, measure the polarisation transfer matrix in the lump after wavelength plate, Polarizer, lens, CCD made up, thereby need not to specify one by one.So just, has the significant advantage that reduces the load of measuring.

Then, the details to correcting measuring and actual measurement describes (with reference to the process flow diagram of Fig. 6).The action both sides are identical, and difference is that measuring object is face Lighting Division 14 in correcting measuring, be blooming 12 in actual measurement.Below be that example describes with the actual measurement.

Correcting measuring, actual measurement all arrange temporary transient output valve storage area and the output valve of storing CCD in computer 16.This output valve storage area is to measure the arrangement that the two-dimensional address of the XY in the measuring table of pixel E is distinguished, and one is arranged key element is the two-dimensional structure of distinguishing with the quantity of as shown in Figure 9 wavelength plate and the measurement number in the wavelength plate, thereby this output valve storage area is four-dimensional on the whole and constructs.

In correcting measuring and actual measurement, at first in making image pickup part 15 under the static state in the assigned position place of Y-direction, make sample platform 13 on directions X, move to the other end from the one end.If sample platform 13 moves then shooting triggering starting and automatically makes a video recording.Face Lighting Division 14 and blooming 12(are arranged hereinafter to be referred as making " blooming 12 etc. " on sample platform 13), when image pickup part 15 is made a video recording till the other end of blooming 12 grades, become the state that the measurement of the field range of camera finishes, thereby in order to change the camera visual field image pickup part 15 is moved on Y-direction with the degree that is equivalent to field range.And then move to an end from the other end of blooming 12 etc., the not camera part of blooming 12 grades is made a video recording.Repeat said procedure, and carry out the shooting of blooming 12 integral body such as grade.

Below expression from shooting to the process of calculating till the S parameter.Moreover CCD is that all pixels are made a video recording simultaneously in the shooting sequential, thereby obtains data from all combining units in 1 shooting, but in the following description, is conceived to a measurement pixel E as typical example and describes.And, for the purpose of simplifying the description, in each the shooting district 50～shooting district 53 of CCD camera 41, arranging 5 combining unit CP at directions X, describe with the some sections that look like the directions X that passed through as the measurement pixel E of object.Moreover, be set at herein and measure pixel E measure-alike with combining unit CP on CCD.This setting can be adjusted according to multiplying power setting or the combining unit number of telecentric lens.

Shown in Figure 10 (A), 5 the 1st combining units that are arranged on the 1st shooting district 50 are made as CP11～CP15,5 the 2nd combining units that are arranged on the 2nd shooting district 51 are made as CP21～CP25,5 the 3rd combining units that are arranged on the 3rd shooting district 52 are made as CP31～CP35, and 5 the 4th combining units that are arranged on the 4th shooting district 53 are made as CP41～CP45.And it is natural number more than 2 that the measurement pixel of blooming 12 is made as E1～En(n).And the interval that shooting that blooming 12 produces when directions X moves is triggered is set to as follows,, measures the distance that pixel E only advances with the length L (=one length of measuring the directions X in the pixel) of the directions X of combining unit on CCD that is.In each shooting district of CCD, arranging 5 combining units at directions X, thereby if one is measured pixel E by each shooting district, then carrying out 5 shootings in each shooting district.

At first, mobile at directions X by blooming, and order is measured on the 1st combining unit CP11 as arrival the 1st shooting district of pixel E1 at a time.And shown in Figure 10 (B), when the image position of measuring pixel E1 was on the 1st combining unit CP11, the 1st combining unit CP11 made a video recording to measuring pixel E1.The output valve that obtains by this shooting is stored among the output valve storage area EM1 that the measurement pixel E1 in the computer 16 use.EM1 is according to two-dimensional arrangements shown in Figure 9, and line direction is the quantity in shooting district, and column direction is the number of measured value.This output valve is stored in the 1st shooting of output valve storage area EM1 and distinguishes among the capable EM11 of usefulness.

Then, if blooming 12 only moves the amount of movement that 1 shooting triggers on directions X, then the image position of the measurement pixel E1 of blooming 12 is on the 1st combining unit district CP12.Then, the 1st combining unit district CP12 makes a video recording to measuring pixel E1.The output valve that obtains by this shooting is stored in another zone of capable EM11 of the 1st shooting district usefulness of measuring the output valve storage area EM1 that pixel E1 uses.And, similarly, in the 1st combining unit district CP13～the 1st combining unit district CP15, make a video recording to measuring pixel E1, and will be stored among the EM11 by the output valve that this shooting obtains.Therefore, distinguish by the 1st shooting by measuring pixel E1, and add up to 5 times shooting.

Then, shown in Figure 11 (A), on the combining unit CP21 in measurement pixel E1 arrives the 2nd shooting district 51, combining unit CP21 makes a video recording to measuring pixel E1.The output valve that obtains by this shooting is stored in the 2nd shooting district of the output valve storage area EM1 in the computer 16 with among the row EM12.And, similarly, make a video recording by the 2nd combining unit CP22～the 2nd combining unit CP25 by measuring pixel E1, and the output valve that is obtained by shooting is stored among the EM12 in regular turn.

And, shown in Figure 11 (B), when measuring pixel E1 by the 3rd combining unit CP31 in the 3rd shooting district 52～the 3rd combining unit CP35, also similarly make a video recording.Output valve in those the 3rd combining units CP31～the 3rd combining unit CP35 when measuring pixel E1 and make a video recording is stored in the 3rd shooting district of output valve storage area EM1 with among the row EM13.And, shown in Figure 11 (C), when measuring pixel E1 by the 4th combining unit CP41 in the 4th shooting district 53～the 4th combining unit CP45, also similarly making a video recording, the 4th shooting district that output valve is stored in output valve storage area EM1 is with going among the EM14.

And, by measuring pixel E1 by the 4th combining unit CP45 in the 4th shooting district 53, the measurement of measuring pixel E1 is finished.Be positioned at the measurement pixel E2 with respect to the place, a rear of the working direction of measuring pixel E1, it is measured to move and postpones to be equivalent to just to begin after 1 shooting triggers with respect to measuring pixel E1, though postponement finishes, what carry out is identical content.Be positioned at rear more measurement pixel E3, E4, E5 ... En respectively and then stagger and be equivalent to 1 shooting and trigger and make a video recording and finish.Those each output valves are stored among output valve storage area EM21～EMn4 that measurement pixel E2～measurement pixel En suitable with the output valve storage area EM11～output valve storage area EM14 shown in Figure 10 (A)～Figure 11 (C) use.Its corresponding relation is shown among Figure 12.

Then, be expressed as follows method: according to the output valve that is stored in the measurement pixel E1 among the output valve storage area EM1 and the polarisation transfer matrix of measuring combining unit specified in the preparation process, and obtain the S parameter of measuring pixel E1.

When obtaining the S parameter of measuring pixel E1, at first, shown in following [several 10], obtain the total of the output valve that is obtained by the shooting in～the 4 shooting district, the 1st shooting district, that is EM11～EM14 separately in the total S11 of 5 output valves of storing _-Σ～S14 _-ΣAmong the present invention, the total of this kind output valve is called measured value, and in S, encloses _ subscript of Σ represents.And initial numeral 1 appended among the S of S11～S14 is equivalent to 1 of E1 for identifying the numbering of measuring pixel and being the primary block corresponding with two-dimensional address originally under this routine situation.The 2nd numeral 1 and 4 is the numbering of employed wavelength plate in measuring corresponding to 1～shooting district, shooting district 4. _-A1～ _-The subscript of A5 is represented the order of a measurement in the shooting district, i.e. the 1st measurement result～5th measurement result.

[several 10]

Measured value S11 _{_ ∑}=S11 _{_ A1}+ S11 _{_ A2}The S11 of+~+ _{_ A5}

Measured value S12 _{_ ∑}=S12 _{_ A1}+ S12 _{_ A2}The S12 of+~+ _{_ A5}

Measured value S13 _{_ ∑}=S13 _{_ A1}+ S13 _{_ A2}The S13 of+~+ _{_ A5}

Measured value S14 _{_ ∑}=S14 _{_ A1}+ S14 _{_ A2}The S14 of+~+ _{_ A5}

On the other hand, intrinsic polarisation transfer matrix is arranged separately in combining unit CP11～combining unit CP45, this value is designated in measuring preparation process.Become [several 11] if the polarisation transfer matrix of CP11～CP45 write out then in regular turn according to definition.

[several 11]

Herein, subscript _ CP11's etc. is numbered the numbering of distinguishing combining unit.

In this example, output valve S11 _{_ CP11}～S14 _{_ CP45}Be indivedual values of measuring gained in combining unit CP11～combining unit CP45, thereby as following [several 12] shown in, should be by the S parameter of polarisation transfer matrix with the measurement pixel E1 of this combining unit | S0 _{_ E1}S1 _{_ E1}S2 _{_ E1}S3 _{_ E1}| ^TMatrix product and define.Herein, subscript _{_}E1 represents to measure the S parameter of pixel E1.

[several 12]

Herein, as if the measured value S11 in [several 10] _{_ Σ}In substitution [several 12] output valve definition and put in order with the S parameter, then obtain [several 13].

[several 13]

Measured value S11 _{_ ∑}=(K _{_ CP11}+ K _{_ CP12}+ K _{_ CP13}+ K _{_ CP14}+ K _{_ CP15}) SO _{_ E1}

+(K_CP11·M _{12_CP11}+K _{_CP12}·M _{12_CP12}+K _{_CP13}·M _{12_CP13}+K _{_CP14}·M _{12_CP14}+K _{_CP15}·M _{12_CP15})·S1 _{_E1}

+(K _{_CP11}·M _{13_CP11}+K _{_CP12}·M _{13_CP12}+K _{_CP13}·M _{13_CP13}+K _{_CP14}·M _{13_CP14}+K _{_CP15}·M _{13_CP15})·S2 _{_E1}

+（K _{_CP11}·M _{14_CP11}+K _{_CP12}·M _{14_CP12}+K _{_CP13}·M _{14_CP13},+K _{_CP14}·M _{14_CP14}+K _{_CP15}·M _{14_CP15})·S3 _{_E1}

In these [several 13], measured value S11 _{_ Σ}Become the form that in each S parameter key element, multiply by some coefficient respectively.Those coefficients are with the known value quadrature of appointment in measuring preparation process, summation gained.Shown in [several 14], define this coefficient group according to the name of known quantity herein.Known quantity can be carried out calculated in advance, can be used as a numerical value later on and handles.

[several 14]

SO _{_ E1}Coefficient=(K _{_ CP11}+ K _{_ CP12}+ K _{_ CP13}+ _{_ CP14}+ K _{_ CP15}) ≡ known quantity O1 _{_ N}

S1 _{_ E1}Coefficient=(K _{_ CP11}M _{12_CP11}+ K _{_ CP12}M _{12_CP12}+ K _{_ CP13}M _{12_CP13}+ K _{_ CP14}M _12-CP14

+ K _{_ CP15}M _{12_CP15}) ≡ known quantity 11 _{_ N}

S2 _{_ E1}Coefficient=(K _{_ CP11}M _{13_CP11}+ K _{_ CP12}M _{13_CP12}+ K _{_ CP13}M _{13_CP13}+ K _{_ CP14}M _{13_CP14}

+ K _CP15M _{13_CP15}) ≡ known quantity 21 _{_ N}

S3 _{_ E1}Coefficient=(K _{_ CP11}M _{14_CP11}+ K _{_ CP12}M _{14_CP12}+ K _{_ CP13}M _{14_CP13}+ K _{_ CP14}M _{14_CP14}

+ K _{_ CP15}M _{14_CP15}) ≡ known quantity 31 _{_ N}

The initial numerical table of following target of known quantity is shown as the key element numbering into the S parameter of coefficient, and the 2nd numeral is for distinguishing the numbering of wavelength plate. _{_}N is the subscript of the position on the Y-direction of distinguishing combining unit, and should handle a section of directions X in the example, thereby becomes the value of certain profile position of expression.

By with in [several 14] substitution [several 13], and obtain following [several 15].

[several 15] measured value S11 _{_ ∑}=(known quantity O1 _{_ N}) SO _{_ E1}+ (known quantity 11 _{_ N}) S1 _{_ E1}+ (known quantity 21 _{_ N}) S2 _{_ E1}+ (known quantity 31 _{_ N}) S3 _{_ E1}

Can be at the measured value S12 of [several 10] _{_ Σ}～measured value S14 _{_ Σ}The identical processing of middle application, thus obtain [several 16].

[several 16]

Measured value S12 _{_ ∑}=(known quantity O2 _{_ N}) SO _{_ E1}+ (known quantity 12 _{_ N}) S1 _{_ E1}

+ (known quantity 22 _{_ N}) S2 _{_ E1}+ (known quantity 32 _{_ N}) S3 _{_ E1}

Measured value S13 _{_ ∑}=(known quantity O3 _{_ N}) SO _{_ E1}+ (known quantity 13 _{_ N}) S1 _{_ E1}

+ (known quantity 23 _{_ N}) S2 _{_ E1}+ (known quantity 33 _{_ N}) S3 _{_ E1}

Measured value S14 _{_ ∑}=(known quantity O4 _{_ N}) SO _{_ E1}+ (known quantity 14 _{_ N}) S1 _{_ E1}

+ (known quantity 24 _{_ N}) S2 _{_ E1}+ (known quantity 34 _{_ N}) S3 _{_ E1}

In 4 formulas with [several 15] and [several 16] merging, unknown number has 4 for the S parameter, and the number of formula has 4, thereby can find the solution.By this, obtain the S parameter of measuring pixel E1.

More than, following situation is illustrated, that is, make a video recording successively by the combining unit of arranging on the directions X on the CCD of a measurement pixel E1 imaging, and finally calculate the S parameter.CCD is that all pixels are made a video recording simultaneously, thus carry out above-mentioned processing during, whole combining units captures the measurement pixel E in the somewhere on the blooming 12, carries out same processing simultaneously.With regard to CCD on the whole, the processing power that has the combining unit amount in the visual field.

So, with the S parameter of measuring pixel E1 ask method similarly, can obtain the S parameter that all measure pixel E.The actual measurement that the S parameter of obtaining is stored in according to the XY address of measuring pixel E in the computer 16 is used in the S parameter storage area.

Under the above-mentioned situation that is measured as correcting measuring, in the variation of measuring pixel E, measure the S parameter of all light projector pixel L of face Lighting Division 14.The S parameter of these all light projector pixel L is stored in the S parameter storage area that the correcting measurings in the computer 16 use.

And the position of the sample platform when trigger according to the starting shooting with the XY address of light projector pixel L the XY address of measuring pixel E determines, thereby position overlapped concerned about the identical measurement pixel E in XY address became with light projector pixel L as a result.And by the dark depth of focus of telecentric lens and the composition of the light parallel with optical axis is distinguished additional function, and the light that irradiation can be measured pixel E be regarded the irradiation from the light projector pixel L of identical XY address as.

And then the starting shooting triggers and can be specified by computer 16 in advance in which position of sample platform 13, but thereby the numerical value calculated in advance that is known as known quantity go out.Has following effect like this: in the purposes that must handle a large amount of measurement data of two-dimensional measurement, play a role for the high speed of handling highly beneficially.

The calculation method of representing the polarized light property of blooming 12 at last.Computer 16 is according to the S parameter of 12 whole of the bloomings of obtaining in whole S parameter of the face Lighting Division of obtaining in the correcting measuring 14 and the actual measurement, and calculates orientations of major and the delay (retardation) of whole of blooming.When being made as from the S parameter that certain of blooming 12 is measured the light that pixel E pass through | 1 Φ Ψ ξ | ^T, be positioned at E under the S parameter of the light that sends of light projector pixel L be made as | 1XYZ| ^TThe time, the birefringent orientations of major α that is positioned at the blooming 12 of measuring pixel E can be represented by [several 17] with slow phasor δ.

[several 17]

tan2α=(φ-X)/(Y-ψ)

cosδ={ξ·Z+(S·φ-C·ψ)·(S·X-C·Y)}/{Z ²+(S·X-C·Y) ²}

sinδ={ξ·(S·X-C·Y)-(S·φ-C·ψ)·Z}/{Z ²+(S·X-C·Y) ²}

Herein, S=sin2 α, C=cos2 α.Utilize this relational expression, all that can calculate blooming 12 are measured the birefringent orientations of major α and slow phasor δ of pixel E, can measure the polarized light property distribution of blooming 12 by this according to the sample resolution.

Moreover, in the explanation of this example, add up to 5 times shooting in each shooting district, and in order to improve measuring accuracy, also can carry out more than 5 times, for example 10 times shooting.Under this situation, undertaken by overlapping (overlap) shooting (1 time the shooting visual field is overlapping with next visual field part of making a video recording) as shown below.

Overlap shooting by carrying out below the length L that 1 amount of movement of making a video recording the sample platform between triggering is made as the directions X of measuring pixel.Setting under the situation of this kind amount of movement, striding and 2 combining units of adjacency and measure pixel to and make a video recording, thus must carry out output valve separately.For example, Figure 13 is the situation of the 2nd shooting in the example of amount of movement between 1 shooting is triggered Figure 10 (A) of 3/10 o'clock, Figure 10 (B) of being set at L, Figure 10 (C).In this shooting sequential, measure pixel E1 and be arranged on the zone of combining unit CP11 7/10, and be arranged on the zone of combining unit CP12 3/10.In the case, definition time combining unit.Directions X is 1/10 the integral multiple of combining unit CP in the inferior combining unit, and Y-direction is identical size with combining unit, thereby the output of the image unit of the CCD that comprises in the inferior combining unit on average is made as the output valve of this time combining unit.Among Figure 13, form the inferior combining unit of CP11 in 7 districts (oblique line is represented), form time output valve S11 _{_ CP11}As output valve, in 3 districts (oblique line is represented) of CP12, form the inferior combining unit of CP12 as it, and form time output valve S11 _{_ CP12}As its output valve, and each output valve is stored among the EM11.And the output valve of this moment is handled as comprising the value of the content shown in [several 18].

[several 18]

SUB output valve S11 _{_ CP11}=0.7K _{_ CP11}(SO _{_ E1}+ M _{12_CP11}S1 _{_ E1}+ M _{13_CP11}S2 _{_ E1}+ M _{14_CP11}S3 _{_ E1})

SUB output valve S11 _{_ CP12}=0.3K _{_ CP12}(SO _{_ E1}+ M _{12_CP12}S1 _{_ E1}+ M _{13_CP12}S2 _{_ E1}+ M _{14_CP12}S3 _{_ E1})

Amount of movement between Figure 14 (A)～Figure 14 (E) expression triggers 1 shooting is set at the situation in 5/10 o'clock the shooting district 50 of L, the situation of time combining unit when Figure 15 represents the 3rd shooting.Measure pixel E1 and in CP11～CP15, add up to 11 times shooting.11 times output valve is defined as [several 19].

[several 19]

◆ the 1st time shooting

SUB output valve S11 _{_ CP11}=0.5K _{_ CP11}(SO _{_ E1}+ M ₁₂_ CP11S1 _{_ E1}+ M _{13_CP11}S2 _{_ E1}+ M _{14_CP11}S3 _{_ E1})

◆ the 2nd time shooting

Output valve S11 _{_ CP11}'=K _{_ CP11}(SO _{_ E1}+ M _{12_CP11}S1 _{_ E1}+ M _{13_CP11}S2 _{_ E1}+ M _{14_CP11}S3 _{_ E1})

◆ the 3rd time shooting

SUB output valve S11 _{_ CP11}The 0.5K of ' '= _{_ CP11}(SO _{_ E1}+ M _{12_CP11}S1 _{_ E1}+ M _{13_CP11}S2 _{_ E1}+ M _{14_CP11}S3 _{_ E1})

SUB output valve S11 _{_ CP12}=0.5K _{_ CP12}(SO _{_ E1}+ M _{12_CP12}S1 _{_ E1}+ M _{13_CP12}S2 _{_ E1}+ M _{14_CP12}S3 _{_ E1})

◆ the shooting of the 4th

Output valve S11 _{_ CP12}'=K _{_ CP12}(SO _{_ E1}+ M _{12_CP12}S1 _{_ E1}+ M _{13_CP12}S2 _{_ E1}+ M _{14_CP12}S3 _{_ E1})

◆ the shooting of the 5th

SUB output valve S11 _{_ CP12}The 0.5K of ' '= _{_ CP12}(SO _{_ E1}+ M _{12_CP12}S1 _{_ E1}+ M _{13_CP12}S2 _{_ E1}+ M _{14_CP12}S3 _{_ E1})

SUB output valve S11 _{_ CP13}=0.5K _{_ CP13}(SO _{_ E1}+ M _{12_CP13}S1 _{_ E1}+ M _{13_CP13}S2 _{_ E1}+ M _{14_CP13}S3 _{_ E1})

◆ the 6th time shooting

Output valve S11 _{_ CP13}'=K _{_ CP13}(SO _{_ E1}+ M _{12_CP13}S1 _{_ E1}+ M _{13_CP13}S2 _{_ E1}+ M _{14_CP13}S3 _{_ E1}

◆ the 7th time shooting

SUB output valve S11 _{_ CP13}The 0.5K of ' '= _{_ CP13}(SO _{_ E1}+ M _{12_CP13}S1 _{_ E1}+ M _{13_CP13}S2 _{_ E1}+ M _{14_CP13}S3 _{_ E1})

SUB output valve S11 _{_ CP14}=0.5K _{_ CP14}(SO _{_ E1}+ M _{12_CP14}S1 _{_ E1}+ M _{13_CP14}S2 _{_ E1}+ M _{14_CP14}S3 _{_ E1})

◆ the 8th time shooting

Output valve S11 _{_ CP14}'=K _{_ CP14}(SO _{_ E1}+ M _{12_CP14}S1 _{_ E1}+ M _{13_CP14}S2 _{_ E1}+ M _{14_CP14}S3 _{_ E1})

◆ the 9th time shooting

SUB output valve S11 _{_ CP14}The 0.5K of ' '= _{_ CP14}(SO _{_ E1}+ M _{12_CP14}S1 _{_ E1}+ M _{13_CP14}S2 _{_ E1}+ M _{14_CP14}S3 _{_ E1})

SUB output valve S11 _{_ CP15}=0.5K _{_ CP15}(SO _{_ E1}+ M _{12_CP15}S1 _{_ E1}+ M _{13_CP15}S2 _{_ E1}+ M _{14_CP15}S3 _{_ E1})

◆ the 10th time shooting

Output valve S11 _{_ CP15}'=K _{_ CP15}(SO _{_ E1}+ M _{12_CP15}S1 _{_ E1}+ M _{13_CP15}S2 _{_ E1}+ M _{14_CP15}S3 _{_ E1})

◆ the 11st time shooting

SUB output valve S11 _{_ CP15}The 0.5K of ' '= _{_ CP15}(SO _{_ E1}+ M _{12_CP15}S1 _{_ E1}+ M _{13_CP15}S2 _{_ E1}+ M _{14_CP15}S3 _{_ E1})

Mark " ' " and mark " " " be for the different marks that mark of the sequential of expressing measurement, there is no other implications.As if being calculated then, the known quantity among this result becomes [several 20].This is [several 14] 2 times, may be interpreted as the result that shooting increases to 2 times.

[several 20]

SO _{_ E1}Coefficient=2 (K _{_ CP11}+ K _{_ CP12}+ K _{_ CP13}+ K _{_ CP14}+ K _{_ CP15})

S1 _{_ E1}Coefficient=2 (K _{_ CP11}M _{12_CP11}+ K _{_ CP12}M _{12_CP12}+ K _{_ CP13}M _{12_CP13}+ K _{_ CP14}M _{12_CP14}+ K _{_ CP15}M _{12_CP15})

S2 _{_ E1}Coefficient=2 (K _{_ CP11}M _{13_CP11}+ K _{_ CP12}M _{13_CP12}+ K _{_ CP13}M _{13_CP13}+ K _{_ CP14}M _{13_CP14}+ K _{_ CP15}M _{13_CP15})

S3 _{_ E1}Coefficient=2 (K _{_ CP11}M _{14_CP11}+ K _{_ CP12}M _{14_CP12}+ K _{_ CP13}M _{14_CP13}+ K _{_ CP14}M _{14_CP14}+ K _{_ CP15}M _{14_CP15})

According to the relational expression of the distribution of [several 18], [several 19] etc., known quantity is revised.The shooting sequential determines by the position of sample platform, measures pixel E and made a video recording and can be designed in advance by which combining unit CP or inferior combining unit in whole shooting sequential.But calculated in advance goes out size and the known quantity of the combining unit in whole shooting sequential.

So, exist respectively to measure among the pixel E and distribute from 2 situations in conjunction with the data of pixel about 1 shooting, but the measured value in a shooting district still can be handled by the additive operation of all output valves that obtain in this shooting district.As a result, the numerical expression of measured value is summed up as the quantity of the kind of wavelength plate, after, the birefringence that utilizes the method identical with above-mentioned explanation to obtain measuring object distributes.

In the present embodiment, the 1st wavelength plate～the 4th wavelength plate 45～48 is about 135 ° wavelength plate for slow phasor, with regard to orientations of major (leading phase shaft orientation), the mode that the 1st wavelength plate 45 becomes roughly 20 ° axle orientation when in Fig. 3 horizontal direction being made as 0 ° is configured, the 2nd wavelength plate 46 be configured in respect to the 1st wavelength plate 45 and the axle orientation roughly increase by 36 ° orientation, the 3rd wavelength plate 47 is configured in respect to the 2nd wavelength plate 46 and then axle orientation increase by 36 ° orientation roughly, and the 4th wavelength plate 48 is configured in respect to the 3rd wavelength plate 47 and then an axle orientation roughly increases by 36 ° orientation.In addition, to be configured in by axle be 0 ° orientation to Polarizer 49.Using the reason of the term of " roughly " to be herein, in the measurement preparation process shown in the process flow diagram of Fig. 6, is that unit specifies the polarisation transfer matrix to image pickup part with combining unit CP, uses the polarisation transfer matrix later on, thereby does not need very strict herein.Roughly be in ± 0.5 ° scope gets final product.

In this example, the kind of wavelength plate is made as 4 kinds, but the kind of wavelength plate also can be more than 4 kinds.For example, under the situation of the wavelength plate that uses N kind (N is the natural number more than 5), N wavelength plate is preferably and is configured to orientations of major with 180 ° of impartial forms of distributing.And the slow phasor of each wavelength plate is preferably roughly 135 °.As long as be this kind formation, then the orientations of major of the 1st wavelength plate can be direction arbitrarily.

The reason that is configured in the above described manner is that coming [several 15], [several 16] error when finding the solution with simultaneous equations (simultaneous equations) is minimum.When according to [several 15], [several 16] and when obtaining the S parameter of light, comprise the noise in the output valve that is attached to CCD in the various measured value (left side).Like this, though those noises are cut down by the average effect of multiple shooting and non-vanishing, thereby be included in the S parameter of finally calculating as error.The noise on the left side that is attached to [several 15], [several 16] is reflected in the amount in the S parameter as error in the computation process of computer 16, by the coefficient of the parameter (S parameter) of [several 15], [several 16] and determine.That is, if make up in the mode that becomes suitable coefficient, then can make the error of calculation (The noise of CCD) of this CCD for minimum.This coefficient selection only depends on the specification (selection of phasor and orientations of major late) of wavelength plate.

As can be known the author to carry out Simulation result repeatedly be as follows.At first, realize also not having the big effect of improving even if increase the quantity of wavelength plate for computational accuracy under the situation of variation of polarized condition using the identical wavelength plate of slow phasor to change the orientations of major of setting.This is because even if the quantity of wavelength plate increases, and the area of 1 wavelength plate reduces, so the fiduciary level of the measured value in 1 wavelength plate descends.And then, if increase the kind of wavelength plate, then can't use the combining unit facing to the border of wavelength plate, thereby the light-receiving area of CCD reduces in fact.The minimizing of light-receiving area means the reduction of S/N ratio.On the other hand, if the quantity of wavelength plate also has the effect of the blocking frequency that can improve noise contained in the signal at most.Consider above-mentioned two kinds of situations, the minimum value of the quantity of wavelength plate is for determining required 4 kinds of S parameter, and maximal value is at most 40.

With regard to the kind of wavelength plate, be preferably and use the identical wavelength plate of slow phasor and the configuration of orientations of major be there are differences, when only being configured 180 ° of angles divided by the quantity gained of wavelength plate are made each other orientation have difference, the error of calculation is minimum.The method to set up that later on this kind is arranged wavelength plate is called equalization and cuts apart, and the number of wavelength plate is called cuts apart number.

On the other hand, be under 45 ° the situation at the interval of wavelength plate differential seat angle, no matter how much quantity of the kind of wavelength plate is, the error of calculation is all bigger.Because wavelength plate is 4 kinds, it is 45 ° that equalization is cut apart angle, cuts apart angle so can't use the error of calculation to should be minimum equalization.Therefore select the configuration of present embodiment.

On the other hand, the slow phasor of wavelength plate such as Figure 16 and as can be known shown in Figure 17, no matter how much quantity of wavelength plate is, per 135 ° have the error of calculation to reach minimum zones.The angle in the orientation of wavelength plate is cut apart and is set at equalization and cuts apart (wherein only 4 being divided into 36 ° of differences).Confirm that 4～40 all that cut apart all have this tendency in cutting apart.

About the position of wavelength plate, in this example, be that the 1st wavelength plate～the 4th wavelength plate 45～48 is arranged on the object side of telecentric lens, but also can replace it and as shown in figure 18, the 1st wavelength plate～the 4th wavelength plate 45～48 is arranged on the dead ahead of CCD camera.Between the 1st wavelength plate～the 4th wavelength plate 45～48 and CCD camera 41, Polarizer 49 is being set herein.

In the case, has the advantage that wavelength plate can be reduced and reduce cost.On the other hand, telecentric lens is from outside the Polarizer thereby have a shortcoming that the error when obtaining the birefringence transport function increases.

And, in this example, represented following mode, that is, use the face Lighting Division 14 of the size that blooming 12 whole faces are thrown light on, and make image pickup part 15 mobile at directions X and Y-direction, but also can be as shown in figure 19, replacement face Lighting Division 14 and use Lighting Division 101, with the field range of width reduction to the Y-direction of the image pickup part 15 that is enough to throw light on, when image pickup part 15 carry out Y when moving Lighting Division 14 also mobile in Y-direction.Under situation about constituting in this way, acquisition can reduce the cost of face Lighting Division 14 and can shorten the effect of the time of obtaining of stoke scholar's parameter.In addition, under the situation of using Lighting Division 101, also can replace sample platform 13, and use the sample platform 102 of the part formation opening of blooming 12 in mounting.

And, in this example, by the measurement that makes 1 CCD camera 41 move the optical characteristics of carrying out blooming 12 integral body in directions X and Y-direction, but in order further to shorten Measuring Time, also can be measured by many CCD cameras.At this moment, as shown in figure 20, the camera CPU of 1 special use is set at 1 camera, and then, be arranged on the host CPU of comprehensive many camera CPU upper.The polarisation transfer matrix of each combining unit of camera places the host CPU side, and each known quantity is also calculated in advance.The S parameter storage area that correcting measuring is used and actual measurement is used also places in the host CPU.The output valve storage area that stores each magazine measurement result also places the host CPU side, but prepares the duplicate (replica) of output valve storage area in advance in camera CPU side.And, being accompanied by the movement towards directions X of measuring table, each CCD camera repeats shooting.Camera CPU is that unit (sometimes in proper order combining unit) calculates output valve and also this output valve is stored in the duplicate (replica) of output valve storage area with the combining unit.Move the movement towards the scanning starting end of directions X with sample platform if arrive Y that the scanning end then is equivalent to the field range of each camera towards the shooting of directions X, but during this moves, do not make a video recording thereby camera CPU there is no the shooting load.Utilize the minimum point of this load and camera CPU carries out copying from the data of the output valve storage area that is copied to the host CPU side of output valve storage area.Host CPU detects the copying and carry out S CALCULATION OF PARAMETERS and storage of the data of output valve storage area, and then carries out the calculating of the polarized light property of blooming.Host CPU does not also have the shooting load in the shooting of CCD camera, so the major part of cpu power is allocated in this calculating.As previously discussed, camera CPU and host CPU all can operate efficiently, thereby can obtain the high speed effect of the processing that realizes by increasing phase board number.

In this example, in correcting measuring and actual measurement, shooting is not begun and finishes to be described in detail, but shooting beginning be invalid in the whole visual field of CCD camera with finishing, thereby the output valve that the shooting thus the time obtains does not also obtain use in calculating afterwards.And the border to the 1st wavelength plate～the 4th wavelength plate is not described in detail, and when the shooting of measuring pixel E was carried out on the border of the 1st wavelength plate～the 4th wavelength plate, the output valve that is obtained by this shooting did not also obtain using in calculating afterwards.This be because, because position detecting mechanism specifies each combining unit of CCD where to catch sample platform 13 all the time, so the unwanted locational information of sample platform can be foreclosed.And then the combining unit of position that is positioned at the seam imaging of wavelength plate is known in advance, therefore can not use this part.

Moreover, among the present invention, be that unit makes a video recording with the combining unit with a plurality of image unit be combined intos of adjacency, but as long as the image unit size fully big and muting problem can also image unit be that unit makes a video recording then.

The main element symbol description:

10: measurement instrument of optical characteristics

12: blooming

13: sample platform

14: the face Lighting Division

15: image pickup part

16: computer

20:X direction travel mechanism

33:Y direction travel mechanism

The 41:CCD camera

The 45～48: the 1st wavelength plate～the 4th wavelength plate

～the 4 shooting district, the 50～53: the 1st shooting district

55： CCD

CP1～CP4: the 1st combining unit～the 4th combining unit

Claims (10)

1. a measurement instrument of optical characteristics is characterized in that, comprising:

Specific polarizing illumination is shone to measuring object in light projector mechanism;

Image mechanism is arranged wavelength plate in the alignment of the 1st direction, realize at least 4 kinds of polarized light properties in above-mentioned the 1st direction, and comprise image sensor that this image sensor is divided into the shooting district to individually making a video recording by the light of above-mentioned wavelength plate; And

Scanning mechanism makes above-mentioned image mechanism with respect to above-mentioned measuring object and relatively mobile in above-mentioned the 1st direction; And

Be accompanied by relatively moving of the above-mentioned image mechanism that undertaken by above-mentioned scanning mechanism, to measure pixel at each and carry out addition in each shooting district, repeatedly the make a video recording output valve that obtains of pixel of respectively measuring of above-mentioned measuring object, and calculate the measured value in this shooting district, and calculate stoke scholar's parameter that each measures the light of pixel according to the measured value of collecting from each shooting district.

2. measurement instrument of optical characteristics according to claim 1, it is characterized in that, the imaging apparatus that above-mentioned image sensor utilization comprises a plurality of pixels is made a video recording, and in when shooting, at each with a plurality of pixels of adjacency in addition be combined into combining unit and export an output valve.

3. measurement instrument of optical characteristics according to claim 1 and 2, it is characterized in that, measure preceding be that unit obtains the polarisation transfer matrix with above-mentioned combining unit, this polarisation transfer matrix is represented the light that sends from above-mentioned measuring object and the relation of distinguishing the output valve of output from each shooting of above-mentioned image sensor, uses above-mentioned polarisation transfer matrix and the output valve of distinguishing output from above-mentioned each shooting to obtain stoke scholar's parameter of above-mentioned measuring object.

4. according to claim 2 or 3 described measurement instrument of optical characteristics, it is characterized in that above-mentioned image sensor is striden and 2 combining units of adjacency and the measurement pixel of regulation is made a video recording.

5. measurement instrument of optical characteristics according to claim 4, it is characterized in that, the output valve of the measurement pixel of afore mentioned rules comprises: will in the combining unit output mean value of the shared ratio of the pixel of measurement pixel after making a video recording of regulation and this pixel be multiplied each other and value, and the multiply each other value of gained of the output mean value of the shared ratio of the pixel after in another combining unit the measurement pixel of stipulating being made a video recording and this pixel.

6. measurement instrument of optical characteristics according to claim 1 and 2, it is characterized in that, above-mentioned travel mechanism makes in above-mentioned measuring object or the above-mentioned image mechanism one of them mobile in the 1st direction, and when the shooting of above-mentioned the 1st direction of the above-mentioned measuring object that is undertaken by above-mentioned image mechanism finished, making in above-mentioned measuring object or the above-mentioned image mechanism one of them had been that right angle and 2nd direction parallel with above-mentioned measuring object are mobile with above-mentioned the 1st direction.

7. measurement instrument of optical characteristics according to claim 6, it is characterized in that, making in above-mentioned measuring object or the above-mentioned image mechanism one of them in above-mentioned travel mechanism is being under the mobile situation of right angle and parallel with above-mentioned measuring object above-mentioned the 2nd direction with above-mentioned the 1st direction, keeping the position relation on above-mentioned the 2nd direction of above-mentioned image mechanism and above-mentioned light projector mechanism and moving it, and the polarisation range of exposures of above-mentioned light projector mechanism is being contracted to the degree of the field range of above-mentioned the 2nd direction of shining of above-mentioned image mechanism.

8. measurement instrument of optical characteristics according to claim 1 and 2 is characterized in that, the quantity of the kind of the polarisation of realizing by above-mentioned wavelength plate is 4 to 40.

9. measurement instrument of optical characteristics according to claim 1 and 2 is characterized in that, it is the slow phase effect that any wavelength plate is identical in 70 ° to 170 ° or 190 ° to 290 ° that above-mentioned wavelength plate has with slow phasor.

10. optical characteristic measurement method is characterized in that:

Use image mechanism, this image mechanism is arranged wavelength plate in the alignment of the 1st direction, realize at least 4 kinds of polarized light properties in above-mentioned the 1st direction, and comprise image sensor, this image sensor is divided into the shooting district to individually making a video recording by the light of above-mentioned wavelength plate

Make image mechanism with respect to measuring object and relatively mobile in above-mentioned the 1st direction, above-mentioned measuring object respectively measured the output valve addition that pixel is repeatedly made a video recording and obtained in each shooting district, and measure the measured value that pixel is calculated this shooting district at each, and according to calculating stoke scholar's parameter of the light that sends from above-mentioned measuring object from the measured value of each shooting district collection similarly and at each measurement pixel.

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