KR20100115832A - Apparatus and method for measuring three dimension shape of phase shifting grating projection using 3 lcd pannels and dichroic prism - Google Patents

Abstract

PURPOSE: An apparatus and a method for measuring three dimension shape of a phase shifting grating projection type using 3 LCD pannels and a dichroic mirror are provided to solve the problems with the relative height measuring, the shadow generation and the precision decrease of the measurement. CONSTITUTION: An apparatus for measuring three dimension shape of a phase shifting grating projection type using 3 LCD pannels and a dichroic mirror comprises a transfer table(114), a light source(90), first and second frequency band filters(91)(92), first to third projection gratings(100)(101)(102), a projecting part, first and second dichroic prisms(104)(105), a conversion prism(106), an image obtaining part, and an optical path changing unit(112). On the transfer table, a target(113) is installed. The light source is installed on or under the transfer table and emits the light. The first frequency band filter filters so that only the light with a wavelength of 600nm or higher can pass. The second frequency band filter filters so that only the light with a wavelength of 550±50nm or higher can pass. The first to third projection gratings generates the grating images using the light filtered in the first and second frequency band filters. The projecting part forms the first to third projection gratings as LCD, DLP or LCOS and consists of a projecting optical system through which the grating image generated in the first projection grating transmits, to help to measure the relative position of an object. The first dichroic prism filters so that only monochromatic light of a wavelength of 600nm or higher of the light of the grating image projected in the projecting part can pass. The second dichroic prism filters so that only monochromatic light of a wavelength of 550±50nm or higher of the light of the grating image projected in the projecting part can pass. The optical path changing unit changes the optical path of the grating image passing through the prism. The image obtaining part is installed on one side of the projecting part and comprises an optical system(110) and a camera(111) which receive the grating image reflected from the target. The image obtaining part receives the grating image reflected from the target and obtains an image. The optical path changing unit changes the optical path of the grating image received from the image obtaining part.

Description

Apparatus and method for measuring three dimension shape of phase shifting grating projection using 3 LCD pannels and dichroic prism

The present invention is to measure an arbitrary three-dimensional shape by using a phase-shift projection moiré generating device, in particular in obtaining a phase using only a projection grid, and after obtaining a moire pattern through a calculation to measure the three-dimensional shape, Simultaneously project the grating using three dichroic mirrors and then measure the projected patterns of different wavelengths separately to completely eliminate shadows on the object side caused by the projector and to calculate absolute coordinates in space The present invention relates to a phase shift projection three-dimensional shape measuring apparatus and a method for shortening the time for simultaneously photographing a projected grid image with one color camera and making it suitable for inspecting light reflected by the light receiving unit.

In general, the word Moire refers to a wave pattern that appears on silks imported from ancient China. The moire phenomenon refers to an interference fringe formed by two or more periodic wave patterns overlapping. That is, the moiré phenomenon is a visual phenomenon of the beat phenomenon, and refers to the interference fringes generated between the objects having a predetermined interval.

The moire fringe is defined as a kind of interference fringe that has a relatively low frequency compared to the reference pattern, which occurs when two or more periodic patterns overlap. This unique low frequency moiré pattern, described as a beat phenomenon, has a wide range of applications ranging from two-dimensional displacement to three-dimensional shape measurements throughout engineering. The moiré method is largely divided into a shadow moire method and a projection moire method according to a method of forming a moire pattern. And if the object has a lot of specular properties, it is possible to measure the three-dimensional shape by using a reflection moire (reflection moire).

In addition, in the measurement of a non-contact three-dimensional object by using a projection moiré method, the conventional moiré apparatus uses a projection grid and a reference grid (see Republic of Korea Patent Application Publication No. 1998-0007797) and a method using only the projection grid (Korea See Published Patent Publication 2002-0039583).

Projection-type moire apparatus using only projection lattice makes multiple lines of projection lattice on the crystal glass substrate by using lithography technology of semiconductor, and when measuring, it takes images of three or more patterns projected while moving the projection lattice at equal intervals. The 3D shape information is obtained using the same.

1 is a block diagram of a conventional moire fringe measuring apparatus, Figure 2 is a view showing a modified stripe shape obtained by FIG.

The operation principle of the projection-type moire apparatus using only the projection grid as shown in FIG. 1 is as follows.

First, after condensing the light source 10 with the condenser lens 12 and projecting the measurement object through the projection grid 14 and the projection lens 16, the projection grid 14 is a three-dimensional shape 18 of the measurement object. Corresponds to the deformed stripes. Thereafter, the deformed stripes are formed on the imaging surface of the CCD (Charge Coupled Device) camera 22 after passing through the imaging lens 20, as shown in FIG. 2.

In order to obtain three or more such images, the grid is moved at a constant amount of equal intervals, photographed and stored in a memory. The moiré pattern can be interpreted in three dimensions by calculating the phase using a bucket algorithm on each of three or more images obtained as described above, and then unwrapping the difference between the reference phase and the object phase.

However, the three-dimensional measurement method as described above has a problem in that it is difficult to measure when the height of the measurement object is higher than that period depending on the period of the moire fringe. Therefore, in the prior art, problems such as relative height measurement, shadow generation, and deterioration of measurement accuracy have occurred, and there is a limit in that absolute spatial three-dimensional coordinates cannot be obtained when the measurement error is reduced.

In addition, in order to measure the above cycle period, there was a disadvantage that the measurement of the projector several times by changing the position of the projector or the position of the camera. Therefore, in the related art, an auto focusing device is required to change the position of the projector or the position of the camera, which increases processing time, increases costs, has a limitation in accuracy and measurement range, and decreases reliability due to position change. I have a problem.

Accordingly, the present invention has been proposed to solve the conventional problems as described above, and an object of the present invention is to obtain a moire fringe using an LCD projection grating and to separate them by frequency to determine the absolute position of an object in space. After the calculation, we propose a method that can measure the three-dimensional shape, and at the same time, using LCD panel and dichroic mirror to develop the three-dimensional shape measuring device to overcome the problem of the conventional method using only the projection grid. A phase shift projection three-dimensional shape measuring apparatus and method are provided.

In addition, another object of the present invention is to be able to easily overcome the above-mentioned problems by using one or more projectors, relatively free to the size of the object to be measured, the step of more than the moiré cycle in the height direction, elimination of the shadow phenomenon by the projection angle, An object of the present invention is to provide a projection lattice generator capable of improving the speed and calculating accuracy of absolute position calculation of a measurement object.

3 is a configuration diagram of a phase shift projection type 3D shape measuring apparatus using three LCD panels and a dichroic mirror according to an embodiment of the present invention.

50nm 파장의 제 2 주파수대역필터(92)와; 상기 제 1 및 제 2 주파수대역필터(91, 92)에서 각각 필터링된 상기 광원(90)의 광을 광경로를 변환시키는 광경로 변환수단(93,94,95)과; 상기 제 1 및 제 2 주파수대역필터(91, 92)에서 필터링된 상기 광원(90)의 광을 각각 이용하여 격자 이미지를 생성시키는 LCD 투영격자(100, 101, 102)와; 상기 LCD 투영격자(100, 101, 102)에서 생성된 격자 이미지를 하나의 동일한 이미지를 투영시킬 수 있도록 합쳐주는 X 프리즘(96)과; 상기 LCD 투영격자(100, 101, 102)에서 생성된 격자 이미지로부터 600nm이상의 파장만이 분리되도록 하는 제 1 다이크로익 거울(104)과 550

50nm 파장만이 분리되도록 하는 제 2 다이크로익 거울(105)과 500nm 이하의 분리된 파장이 분리되어 투영되도록 제 3 다이크로익 거울(106)로 구성된 투영광학계가 위치하도록 한 투영부(200)와; 상기 투영부(200)에서 투영된 격자 이미지의 광경로를 변환시키는 광경로 변환수단(107, 108, 109)과; 상기 투영부(200)의 일측에 설치되며, 상기 측정대상물(113)로부터 반사되는 격자이미지를 수광하도록 하는 광경로 변환수단(112)과 광학계(110) 및 카메라(111)를 구비하여 영상을 획득하는 영상획득부(300);를 포함하여 구성된 것을 특징으로 한다.As shown therein, a transfer table 114 on which the measurement object 113 may be installed; A light source 90 installed above or below the transfer table 114 to emit light; The first frequency band filter 91 and 550 having a wavelength of 600 nm or more for filtering only the single color light through the light of the light source 90, respectively.

A second frequency band filter 92 having a wavelength of 50 nm; Optical path converting means (93,94,95) for converting light of the light source (90) filtered by the first and second frequency band filters (91, 92), respectively; An LCD projection grid (100, 101, 102) for generating a grating image using the light of the light source (90) filtered by the first and second frequency band filters (91, 92), respectively; An X prism (96) for combining the grid images generated by the LCD projection grids (100, 101, 102) to project one identical image; First dichroic mirror 104 and 550 to separate only wavelengths of 600 nm or more from the lattice images generated by the LCD projection grids 100, 101, and 102

Projection unit 200 in which a projection optical system composed of a second dichroic mirror 105 allowing only 50 nm wavelength to be separated and a third dichroic mirror 106 so that the separated wavelength of 500 nm or less is projected separately is located Wow; Optical path converting means (107, 108, 109) for converting the optical path of the grid image projected by the projection unit (200); It is installed on one side of the projection unit 200, and equipped with an optical path converting means 112, an optical system 110 and a camera 111 to receive a grid image reflected from the measurement object 113 to acquire an image It characterized in that it comprises a; image acquisition unit 300.

The first and second dichroic mirrors (91, 92) is characterized in that the filtering to be projected to 400nm to 900nm wavelength.

The first, second, and third dichroic mirrors 104, 105, and 106 are filtered to project light having a wavelength of 400 nanometers to 900 nanometers.

The first projection lattice 100, the second projection lattice 101, the third projection lattice 102, and the optical path converting means 107, 108, and 109 may be a liquid crystal display (LCD) panel or a digital light source (DLP). It is characterized in that the lattice generated by Processing or Liquid Crystal on Silicon (LCOS) is projected.

4 is a view illustrating a position where a projection unit and an image acquisition unit may be installed in FIG. 3.

As shown in the drawing, the projection unit 200 is located in the upward direction of the measurement object 113, and positioned so as to position the central axis of the light beam within a range of 17 degrees to 30 degrees with respect to the vertical upward direction. It is done.

5 is a configuration diagram showing an example in which the control module unit and the central control unit in FIG.

As shown in the drawing, first, second, and third projection gratings for generating a grid image by using light from the light source 90 to obtain a correction plane phase and an object phase of the measurement object 113 ( 100, 101, 102; First and second and second grids for calculating the height of the measurement object 113 by allowing the grid images generated by the first, second, and third projection grids 100, 101, and 102 to be transmitted, respectively. Third projection portions 107, 108, 109; It is provided on one side of the projection unit 116, and provided with an optical system 110 and a camera 111 to receive the grid image reflected from the measurement object 113, and converts the optical path of the received grid image An image acquisition unit (300) having light path conversion means (112) to receive the grid image reflected from the measurement object (113) to obtain an image; And a central controller 500 that calculates the height of the unwrapped object with respect to the image obtained by the image acquisition unit 300.

The central control unit 500 may calculate the height of the object by unwrapping the object phase after obtaining the bias magnitude of the object by using the correction plane phase acquired by the projection unit 200.

The first, second, and third projection grids 100, 101, and 102 may output an image in which micro displacements are moved by LCD or DLP to LCOS (not shown).

The control module unit 400 includes a motor driver 410 for driving the driving means 230 of the transfer table in the measurement object transfer unit; A camera power supply unit 420 for supplying power to the camera 111 in the image acquisition unit 300; An LCD panel driver 430 for controlling the operation of the LCD projection grids 100, 101, and 102 in the projection grid projection unit 200; And an illumination power supply device 440 for supplying power to a light source in the projection grid projection unit 200.

The central control unit 500 obtains the bias magnitude of the object using the correction plane phase obtained by the projection unit 200, and then unwraps the object phase and adjusts the correction plane phase of the projection unit 200. It is characterized in that to calculate the height of the unwrapped object using.

The central control unit 500 includes a motor control board 510 for controlling the operation of the motor driver 410 in the control module unit 400; An image board 520 for processing an image acquired from the camera 111 in the image acquisition unit 300; And an interface board 530 for interfacing with the camera power supply device 420, the LCD panel driver 430, and the lighting power supply device 440 in the control module unit 400.

6 is a flowchart illustrating a method of measuring a phase shift projection type 3D shape using a dichroic mirror according to an embodiment of the present invention.

50nm 그리고 600nm 이상 대역의 주파수를 분리하여 분리된 각각의 영상을 이용 보정면위상1과 보정면위상2 그리고 보정면위상3에 대한 기준위상을 획득하는 제 1 단계(ST11 ~ ST16)와; 상기 투영부(200)를 이용하여 측정대상물(113)에 상기 제 1 투영격자(100)와 제 2 투영격자(101) 그리고 제 3 투영격자(102)를 다이크로익 거울(91,92)을 통해 주파수를 분리하여 동시에 조사하고, 컬러 카메라를 통해 촬영된 영상으로부터 500nm 이하 대역의 주파수와 550

50nm 그리고 600nm 이상 대역의 주파수를 분리하여 분리된 각각의 영상을 이용 물체위상1과 물체위상2 그리고 물체위상3에 대한 기준위상을 획득하는 제 2 단계(ST17 ~ ST22)와; 상기 획득된 보정면위상1, 물체위상1, 보정면위 상2, 물체위상2, 보정면위상3, 물체위상3을 이용하여 물체의 바이어스 크기를 구하고 물체위상을 언래핑하며 언래핑된 물체의 높이를 산출하는 제 3 단계(ST31 ~ ST34);를 포함하여 수행하는 것을 특징으로 한다.As shown in the drawing, the first projection grid 100, the second projection grid 101, and the third projection grid 102 are disposed on the correction plane using the projection unit 200. The frequency is separated and irradiated at the same time through the camera.

A first step (ST11 to ST16) of acquiring reference phases for the correction plane phase 1, the correction plane phase 2, and the correction plane phase 3 by using respective images separated by separating the frequencies of the 50 nm and 600 nm bands; The first projection grid 100, the second projection grid 101, and the third projection grid 102 are placed on the measurement object 113 using the projection unit 200. The frequency is separated and irradiated at the same time.

A second step (ST17 to ST22) of acquiring reference phases for the object phase 1, the object phase 2, and the object phase 3 by using respective images separated by separating frequencies of 50 nm and 600 nm or more bands; Using the obtained correction plane phase 1, object phase 1, correction plane phase 2, object phase 2, correction plane phase 3, object phase 3 to obtain the bias size of the object, unwrapped the object phase and the height of the unwrapped object It comprises a third step (ST31 ~ ST34) for calculating the.

50nm로 수광된 상기 제 2 투영격자(101)의 이동영상을 버킷알고리즘에 적용하며, 카메라(111)에 500nm 이하로 입력된 상기 제 3 투영격자(102)의 이동영상을 버킷알고리즘에 적용하는 제 14 및 제 15 단계(ST14, ST15)와; 상기 제 14 단계의 상기 버킷알고리즘 적용에 의해 보정면위상1에 대한 기준위상을 획득하고, 버킷알고리즘 적용에 의해 보정면위상2에 대한 기준위상을 획득하며, 버킷알고리즘 적용에 의해 보정면위상3에 대한 기준위상을 획득하는 제 16 단계(ST16);를 포함하여 수행하는 것을 특징으로 한다.In the first steps ST11 to ST16, the first projection lattice 100, the second projection lattice 101, and the third projection lattice 102 are simultaneously irradiated onto the correction surface using the projection unit 200. A twelfth step ST12; A thirteenth step (ST13) of acquiring an image by simultaneously converting the first projection grid (100), the second projection grid (101), and the third projection grid (102) using the projection unit (200); A moving image of the first projection grating 100 received at 600 nm or more by the camera 111 is applied to a bucket algorithm, and the camera 111 is 550.

Applying a moving image of the second projection lattice 101 received at 50 nm to the bucket algorithm, and applying a moving image of the third projection lattice 102 input to the camera 111 at 500 nm or less to the bucket algorithm. 14 and 15 steps ST14 and ST15; The reference phase for the correction plane phase 1 is obtained by applying the bucket algorithm of the fourteenth step, the reference phase for the correction plane phase 2 is obtained by applying the bucket algorithm, and the correction plane phase 3 is applied to the bucket plane algorithm by the bucket algorithm. And a sixteenth step ST16 of acquiring the reference phase.

The fifteenth step may be applied using one of three, four, five, and seven bucket algorithms.

50nm로 입력된 상기 제 2 투영격자(101)의 이동영상을 버킷알고리즘에 적용하며, 카메라(111)에 500nm 이하로 입력된 상기 제 3 투영격자(102)의 이동영상을 버킷알고리즘에 적용하는 제 24 및 제 25 단계(ST24, ST25)와; 상기 제 24 단계의 상기 버킷알고리즘 적용에 의해 상기 물체위상1에 대한 기준위상을 획득하고, 버킷알고리즘 적용에 의해 상기 물체위상2에 대한 기준위상을 획득하며, 버킷알고리즘 적용에 의해 상기 물체위상3에 대한 기준위상을 획득하는 제 26 단계(ST26);를 포함하여 수행하는 것을 특징으로 한다.In the second steps ST21 to ST26, the first projection lattice 100, the second projection lattice 101, and the third projection lattice 102 are formed on the measurement object 240 using the projection unit 200. A twenty-second step of simultaneously irradiating (ST22); A twenty-third step (ST23) of acquiring an image by simultaneously converting the first projection grid (100), the second projection grid (101) and the third projection grid (101); The moving image of the first projection grid 100 input to the camera 111 at 600 nm or more is applied to the bucket algorithm, and 550 is applied to the camera 111.

Applying a moving image of the second projection lattice 101 input at 50 nm to the bucket algorithm, and applying a moving image of the third projection lattice 102 input to the camera 111 at 500 nm or less to the bucket algorithm. 24 and 25th steps ST24 and ST25; The reference phase for the object phase 1 is obtained by applying the bucket algorithm of the twenty-fourth step, the reference phase for the object phase 2 is obtained by applying the bucket algorithm, and the object phase 3 is applied to the object phase 3 by applying the bucket algorithm. And a twenty sixth step (ST26) of acquiring a reference phase.

The twenty-third step may be applied using one of three, four, five, and seven bucket algorithms.

The third step ST31 to ST34 may include a thirty-first step ST31 of obtaining a bias size using the correction plane phase 3 of the first step and the object phase 3 of the second step; A thirty-second step (ST32) of unbiasing the object phases 1 and 2 of the second step by using the bias magnitude obtained in the thirty-first step; A step 33 (ST33) of unwrapping the object phases 1 and 2 unbiased in the 32nd step; A thirty-fourth step (ST34) for calculating the height of the measurement object 113 with respect to the object phase 1 and the object phase 2 unwrapped in the thirty-third step using the correction surface phase 1 and the correction surface phase 2; It is characterized by performing, including;

The three-dimensional phase shift projection type three-dimensional shape measuring device and measuring method using three LCD panels and a dichroic mirror according to the present invention do not use a reference grid, which has been conventionally implemented, and has a relative relationship with the prior art using only one projection grid. Problems such as height measurement, shadow generation and deterioration of measurement accuracy can be solved, and absolute three-dimensional coordinates can be obtained while reducing measurement errors. Therefore, eliminating the auto focusing device reduces processing time and has the effect of higher precision, wider measuring range, and improved reliability at low cost.

Referring to the accompanying drawings, a preferred embodiment of a three-dimensional phase shift projection type three-dimensional shape measuring apparatus and a measuring method using three LCD panels and a dichroic mirror according to the present invention configured as described above are as follows. In the following description of the present invention, detailed descriptions of well-known functions or configurations will be omitted if it is determined that the detailed description of the present invention may unnecessarily obscure the subject matter of the present invention. It is to be understood that the following terms are defined in consideration of the functions of the present invention, and may be changed according to the intention of the user, the operator, or the precedent, and the meaning of each term should be interpreted based on the contents will be.

First, the present invention obtains a phase using only a projection grid, obtains a moire pattern through calculation, and then, when measuring a three-dimensional shape, it is possible to calculate an object having a vertical step larger than one period of the moiré. It is designed not to use auto focusing device because it can completely remove shadows and calculate absolute coordinates in space.

In the configuration of acquiring the moire pattern using only the projection grid, the phase shift projection type moire apparatus using the projection grid generator configured to output the micro-moved image by using the image formed by using the LCD panel as the projection grid. This will be described in detail with reference to FIG. 5.

First, the present invention may be configured to include one or more of the projection grid projection unit 200, the measurement object transfer unit 114, the image acquisition unit 300, the control module unit 400, the central control unit 500.

Thus, in the projection grid projection unit 200, the light source 90 is installed above or below the transfer table 114, and emits light.

The condensed light source 90 passes through the first, second and third projection grids 100, 101, 102.

The first and second frequency band filters 91 and 92 filter so that only specific band wavelengths may pass through the light of the focused light source 90, respectively. In this case, the filtering is performed in the range of 370 nanometers to 1000 nanometers. The optimal condition is to filter light from 400 nanometers to 800 nanometers.

50nm 그리고 600nm 이상의 광을 각각 이용하여 격자 이미지를 생성시킨다.The first, second, and third projection gratings 100, 101, and 102 are 500 nm or less and 550 filtered by the first and second frequency band filters 91, 92.

Lattice images are generated using 50 nm and 600 nm or more light, respectively.

The grid images are converted into a shifted form at regular intervals using the first, second and third LCD projection grids 100, 101, and 102. The first, second and third LCD projection grids 100, 101 and 102 may be configured in place of DLP to LCOS.

The projection unit 200 includes a projection optical system through which the grid images generated by the first, second, and third LCD projection grids 100, 101, and 102 are transmitted to assist in measuring the relative position of the object. The projection unit 200 is positioned in the upward direction of the measurement object 113 and positioned within a range of 17 degrees to 30 degrees with respect to the vertical upward direction.

The optical path converting means 107, 108, 109 converts the optical paths of the grating images projected from the first, second and third LCD projection grids 100, 101, and 102 to the measurement object 113 at the same time. do.

In addition, the transfer table 114 in the measurement object transfer unit allows to place the measurement object 113.

In addition, the driving unit 115 of the transfer table in the measurement object transfer unit is driven by the motor driver 410 of the control module unit 400 under the control of the motor control board 510 of the central control unit 500 to transfer the transfer table 114. ).

In addition, the image acquisition unit 300 is installed on one side of the projection unit 200.

In the image acquisition unit 300, the optical system 110 and the camera 111 receive a grid image reflected from the measurement object 113 and transmit the received image to the image board 520 of the central controller 500.

The control module unit 400 controls the operations of the projection grid projection unit 200 and the image acquisition unit 300.

Thus, the motor driver 410 in the control module unit 400 controls the motor control board 510 of the central control unit 500 to drive the driving means 115 of the transfer table in the measurement object transfer unit.

In addition, the camera power supply unit 420 in the control module unit 400 to interface with the interface board 530 of the central control unit 500 to supply power to the camera 111 in the image acquisition unit 300.

In addition, the lighting power supply unit 430 in the control module unit 400 interfaces with the interface board 530 of the central control unit 500 to supply power to the light source 90 in the projection grid projection unit 200.

In addition, the LCD panel driving driver 440 in the control module unit 400 interfaces with the interface board 530 of the central control unit 500 so that the first, second and third LCD panels in the projection grid projection unit 200 can be controlled. Control the operation of (100, 101, 102).

The control module 400 is then controlled, and the height of the unwrapped object is calculated for the image acquired by the image acquisition unit 300. Thus, after obtaining the bias size of the object using the correction plane phase acquired by the projection unit 200, the object phase is unwrapped, and the height of the unwrapped object is increased using the correction plane phase of the projection unit 200. Will be calculated.

In the central control unit 500, the motor control board 510 controls the operation of the motor driver 410 in the control module unit 400.

In addition, in the central control unit 500, the image board 520 processes the image obtained from the camera 111 in the image acquisition unit 300.

In addition, the interface board 530 in the central control unit 500 interfaces with the camera power supply unit 420, the lighting power supply unit 430, and the LCD panel driver 440 in the control module unit 400.

Referring to the process of obtaining a moire pattern using such a device as follows.

50nm 파장의 격자무늬와 제 3 투영격자(102)를 통해 500nm 이하 파장의 격자무늬를 보정면에 영사하고(ST12), 격자무늬를 비꿔가며 영상을 획득한다(ST13). 그리고 조사된 격자를 수광하는 컬러 카메라(111)가 장착된 수광부인 영상획득부(300)에서 획득하며(ST14), 이를 적색과 녹색 그리고 청색의 3원색으로 분리한 후 3버킷, 4버킷, 5버킷, 7버킷 알고리즘 가운데 하나를 사용하여(ST15), 600nm 이상의 파장대역에 대한 보정면위상1과 550

50nm 파장대역에 대한 보정면위상2 그리고 500nm 이하의 파장대역에 대한 보정면위상3에 대한 기준위상을 계산한 후 메모리에 저장한다(ST16).1) Projecting a lattice pattern with a wavelength of 600 nm or more through the first projection lattice 100 of the projection unit 200 in a state where there is no measurement object to the correction plane, and simultaneously using the second projection lattice 550.

The grid pattern having a wavelength of 500 nm or less is projected onto the correction surface through the grid pattern of 50 nm wavelength and the third projection lattice 102 (ST12), and the image is acquired by emptying the grid pattern (ST13). And it is obtained from the image acquisition unit 300, which is a light receiving unit equipped with a color camera 111 for receiving the irradiated grid (ST14), after separating it into three primary colors of red, green and blue, three buckets, four buckets, five Bucket, using one of the seven bucket algorithms (ST15), compensation plane phases 1 and 550 for wavelengths above 600 nm

The reference phase for the compensation plane phase 2 for the 50 nm wavelength band and the compensation plane phase 3 for the wavelength band of 500 nm or less is calculated and stored in the memory (ST16).

50nm 파장의 격자무늬와 제 3 투영격자(102)를 통해 500nm 이하 파장의 격자무늬를 보정면에 영사하고(ST21), 격자무늬를 바꿔가며 영상을 획득한다(ST23). 그리고 조사된 격자를 수광하는 컬러 카메라(111)가 장착된 수광부인 영상획득부(300)에서 획득하며(ST24), 이를 적색과 녹색 그리고 청색의 3원색으로 분리한 후 3버킷, 4버킷, 5버킷, 7버킷 알고리즘 가운데 하나를 사용하여(ST25), 600nm 이상의 파장대역에 대한 물체위상1과 550

50nm 파장대역에 대한 물체위상2 그리고 500nm 이하의 파장대역에 대한 물체위상3에 대한 기준위상을 계산하고, 물체위상에 대한 기준위상을 계산한 후 메모리에 저장한다(ST26).2) Place the measurement object 113 and project the grid pattern of 600 nm or more wavelength through the first projection grating 100 of the projection unit 200 to the correction plane and at the same time 550 through the second projection grating 101.

The grid pattern having a wavelength of 500 nm or less is projected onto the correction plane through the grid pattern of 50 nm wavelength and the third projection grid 102 (ST21), and the image is acquired by changing the grid pattern (ST23). And it is obtained from the image acquisition unit 300, which is a light receiving unit equipped with a color camera 111 for receiving the irradiated grid (ST24), after separating it into three primary colors of red, green and blue, 3 bucket, 4 bucket, 5 Bucket, using one of the seven bucket algorithms (ST25), object phases 1 and 550 for wavelengths above 600 nm

The reference phase for the object phase 2 for the 50 nm wavelength band and the object phase 3 for the wavelength band less than 500 nm are calculated, and the reference phase for the object phase is calculated and stored in the memory (ST26).

3) The size of the bias is obtained by calculating the compensation surface phase 3 obtained in 1) and the object phase 3 obtained in 2) above (ST31).

4) The bias calculated in 3) is unbiased from the object phases 1 and 2 (ST32).

5) The unbiased object phases 1 and 2 of the object obtained in 2) are unwrapped (ST33), and the height data of the measurement object is obtained using the correction plane phase 1 (ST34).

The process of obtaining the magnitude of the bias, the unbiasing process, the unwrapping process, and the solution of the polynomial used to obtain the height data of the measurement object are well known to those skilled in the art, and thus the detailed description thereof will be omitted.

Algorithms for obtaining phase information generally include 3 buckets, 4 buckets, 5 buckets, 7 buckets, 9 buckets, and 11 buckets. Among them, the 5 bucket algorithm is expressed as follows.

라 하고,The amount of phase shift

,

라 할 때,The light intensity of the image observed by the CCD camera

When we say

는 다음의 수학식 1 내지 수학식 4와 같이 표현될 수 있다.Phase corresponding to the image obtained through phase shift

May be expressed as Equation 1 to Equation 4 below.

Five light intensities are converted into phases at one point by the above equations (1) through (4). Equations 1 to 4 may be equally applied to the correction surface and the measurement object, and when the phase difference is expressed by the displacement of the height, it may be represented by the following Equations 5 to 7 through FIG. have.

를 사인(sine) 정현파의 주기라 하고,

를 위상차라 한다.here

Is called the sine sinusoidal cycle,

Is called the phase difference.

와

의 평면에 대한 위상차만을 고려한다면,

의 요소를 무시할 수 있게 된다. 위상에 대한 높이의 관계식은 높이

에 대하여 위상차의 총합으로 표현되어 다음의 수학식 8로 표현할 수 있다.

Wow

Considering only the phase difference with respect to the plane of

The element of can be ignored. The relationship of height to phase is

With respect to the sum of the phase difference can be expressed by the following equation (8).

과

그리고

를 수학식 8에 대입하면 다음의 수학식 9와 같이 정리된다.remind

and

And

Is substituted into Equation 8, it is arranged as Equation 9 below.

,

,

이다.here,

,

,

to be.

The above equations describe a three-dimensional change in phase with a height observed using an interfering waveform. If the three-dimensional space is projected on the two-dimensional space and the amount of phase change is not observed, the following equation (10) may result.

In addition, it can be seen that Equations 9 and 10 are arranged as in Equation 11 below.

Solving the equations (9), (10), (11) into (8) to obtain the following equation (12).

라 할 때 수학식 12는 다음의 수학식 13과 같이 계산되어질 수 있다.Eventually, the sum of the phase shifts is converted into height.

Equation 12 may be calculated as Equation 13 below.

If there is no element that cannot be unwrapped except shadows, the method of obtaining shadow information generated by the projector is used as the residual theory, and the size of the image received by the CCD is horizontal m and vertical n. When the positions of all the pixels are expressed by i in the x direction and j in the y direction, they are expressed as in Equation 14 below.

는 y 방향으로의 편미분된 언래핑 값이고,

는 x 방향으로의 편미분된 언래핑 값이다.here,

Is the undifferentiated unwrapping value in the y direction,

Is the undifferentiated unwrapping value in the x direction.

The remaining values generated by the shadow may be reduced as shown in Equation 15 below.

The actual measurement process will be described with reference to FIGS. 5 and 6 as follows.

First, the present invention obtains three-dimensional information of a measurement object using a correction plane, and a method of obtaining a reference phase, a method of obtaining a phase of the measurement object, and a three-dimensional measurement object using a correction plane as shown in FIG. 5. It is divided into ways of obtaining information.

First, the step of using the projection unit 200 will be described.

50nm 의 파장으로 필터링한 후 제 1 투영격자(100)를 지나게 하고 600nm 이상의 파장으로 필터링한 후 제 2 투영격자(101)를 지나게 하며, 500nm 이하의 파장으로 필터링한 후 제 3 투영격자(102)를 지나게 한 후, X프리즘을 이용하여 격자이미지를 합쳐 투영광학계(103)로써 보정면에 영사한다. 이때, 영사된 빛은 120도 간격으로 배열되어 600nm 이상의 파장만이 지날 수 있도록 다이크로익 코팅 처리된 프리즘(104)과 550

50nm 의 파장만이 지날 수 있도록 다이크로익 코팅 처리된 프리즘(105) 그리고 500nm 이하의 파장이 지날 수 있도록 한 광경로 변환 프리즘(106)을 지나게 된다. 3버킷, 4버킷, 5버킷, 7버킷 알고리즘 가운데 하나를 적용할 수 있도록 투영격자(100, 101, 102)의 무늬를 등간격으로 바꿔가면서 보정면에 영사한 후 컬러 카메라(111)와 영상보드(520)를 통해 획득한다. 상기 획득한 격자무늬 영상을 적색과 녹색 그리고 청색의 3원색으로 분리한 후 3버킷, 4버킷, 5버킷, 7버킷 알고리즘 가운데 하나를 사용하여 중심파장이 640nm 인 보정면위상1과 중심파장이 550nm 인 보정면위상2 그리고 중심파장이 470nm 인 보정면위상3을 획득하여 언래핑 한다. 상기와 같은 행위를 보정면의 연직 상하방향으로 모아레 주기가 1주기 변할 때까지 반복하여 보정면위상을 메모리에 저장한다.Place the compensation surface on the transfer table 114 and light 550 from the light source 90

After filtering at a wavelength of 50nm and passing through the first projection lattice 100 and filtering to a wavelength of 600nm or more and then to pass through the second projection lattice 101, after filtering to a wavelength of 500nm or less after the third projection lattice 102 After passing through, the grid images are combined using an X prism and projected onto the correction surface with the projection optical system 103. At this time, the projected light is arranged at intervals of 120 degrees so that only a wavelength of 600 nm or more passes through the dichroic coated prism 104 and 550

Pass the dichroic coated prism 105 to pass only 50 nm wavelength and the light path conversion prism 106 to pass the wavelength below 500 nm. After applying the three-, four-, five-, or seven-bucket algorithms, the projection grids 100, 101, and 102 are patterned at equal intervals and projected onto the correction surface, followed by the color camera 111 and the image board. Acquire through 520. After the obtained grid pattern image is separated into three primary colors of red, green, and blue, the correction plane phase 1 having a center wavelength of 640 nm and the center wavelength of 550 nm using one of three buckets, four buckets, five buckets, and seven bucket algorithms. We obtain and correct the phosphorus correction plane phase 2 and the correction plane phase 3 whose center wavelength is 470 nm. The above-described behavior is repeated in the vertical up and down direction of the correction plane until the moiré cycle changes by one cycle, and the correction plane phase is stored in the memory.

Next, a step of obtaining a phase of an object corresponding to the measurement object 113 will be described.

50nm 의 파장으로 필터링한 후 제 1 투영격자(100)를 지나게 하고 600nm 이상의 파장으로 필터링한 후 제 2 투영격자(101)를 지나게 하며, 500nm 이하의 파장으로 필터링한 후 제 3 투영격자(102)를 지나게 한 후, X프리즘을 이용하여 격자이미지를 합쳐 투영광학계(103)로써 측정대상물에 영사한다. 이때, 영사된 빛은 120도 간격으로 배열되어 600nm 이상의 파장만이 지날 수 있도록 다이크로익 코팅 처리된 프리즘(104)과 550

50nm 의 파장만이 지날 수 있도록 다이크로익 코팅 처리된 프리즘(105) 그리고 500nm 이하의 파장이 지날 수 있도록 한 광경로 변환 프리즘(106)을 지나게 된다. 3버킷, 4버킷, 5버킷, 7버킷 알고리즘 가운데 하나를 적용할 수 있도록 투영격자(100, 101, 102)의 무늬를 등간격으로 바꿔가면서 측정대상물에 영사한 후 컬러 카메라(111)와 영상보드(520)를 통해 획득한다. 상기 획득한 격자무늬 영상을 적색과 녹색 그리고 청색의 3원색으로 분리한 후 3버킷, 4버킷, 5버킷, 7버킷 알고리즘 가운데 하나를 사용하여 중심파장이 640nm 인 물체위상1과 중심파장이 550nm 인 물체위상2 그리고 중심파장이 470nm 인 물체위상3을 획득하여 언래핑 한다.The measurement object 113 is placed on the transfer table 114 and the light of the light source 90 is 550.

After filtering at a wavelength of 50nm and passing through the first projection lattice 100 and filtering to a wavelength of 600nm or more and then to pass through the second projection lattice 101, after filtering to a wavelength of 500nm or less after the third projection lattice 102 After passing through, the grid images are combined using an X prism and projected onto the measurement object with the projection optical system 103. At this time, the projected light is arranged at intervals of 120 degrees so that only a wavelength of 600 nm or more passes through the dichroic coated prism 104 and 550

Pass the dichroic coated prism 105 to pass only 50 nm wavelength and the light path conversion prism 106 to pass the wavelength below 500 nm. After applying the three-, four-, five-, or seven-bucket algorithms, the projection grids 100, 101, and 102 are patterned at equal intervals and projected onto the measurement object, followed by the color camera 111 and the image board. Acquire through 520. The obtained grid pattern image is separated into three primary colors of red, green, and blue, and then an object phase 1 having a center wavelength of 640 nm and a center wavelength of 550 nm using one of three bucket, four bucket, five bucket, and seven bucket algorithms. The object phase 2 and the object phase 3 having a center wavelength of 470 nm are acquired and unwrapped.

Then, the object phase 3 and the compensation plane phase 3 are compared to obtain the bias size of the object from the measurement origin of the system. The magnitude of the bias is unbiased with respect to the object phase 1, and the actual height information of the measurement object is obtained by a polynomial using the correction plane phase 1 obtained by the projection unit 200. The rest of the object phase 1, which is not calculated due to the shadows, is unbiased for the acquired compensation plane phase 2 and the object phase 2, and the compensation plane phase 3 and the object phase 3 and then measured by the polynomial using the compensation plane phase 1. Obtain and replace the actual height information of the object.

8 shows the result of the actual implemented system as a program. It was intended to prove the usefulness of the present invention by implementing three-dimensional measured forms in three dimensions.

As described above, the present invention obtains a phase using only a projection lattice, obtains a moire pattern through calculation, and then, when measuring a three-dimensional shape, it is possible to calculate an object having a vertical step larger than one period of the moire. By completely eliminating shadows and enabling calculation of absolute coordinates in space, the first and second projection grids can be transported at the same time, reducing the time for receiving the projected grid image in half, and auto focusing. It is designed so that the device is not used to check the light reflected by the light receiving unit.

Although the above has been described as being limited to the preferred embodiment of the present invention, the present invention is not limited thereto and various changes, modifications, and equivalents may be used. Therefore, the present invention can be applied by appropriately modifying the above embodiments, it will be obvious that such application also belongs to the scope of the present invention based on the technical idea described in the claims below.

1 is a block diagram of a conventional moire fringe measuring apparatus.

FIG. 2 is a view showing a modified stripe shape obtained by FIG. 1. FIG.

3 is a configuration diagram of a phase shift projection type three-dimensional shape measuring apparatus using three LCD panels and a dichroic mirror according to an embodiment of the present invention.

4 is a view illustrating a position where the first projection unit and the second projection unit may be installed in FIG. 3.

5 is a configuration diagram showing an example in which the control module unit and the central control unit in FIG.

6 is a flowchart illustrating a method of measuring a phase shift projection type 3D shape using a dichroic mirror according to an embodiment of the present invention.

FIG. 7 is a diagram for describing a process of obtaining a coefficient in which the sum of phase shifts is converted into heights in the present invention.

8 is a view showing a result of measuring the object to be measured in three dimensions by a program actually implemented by the present invention.

Explanation of symbols on the main parts of the drawings

90 light source 91 first frequency band filter

92 second frequency band filter 93 specular reflection mirror

94: specular reflection mirror 95: specular reflection mirror

96: X prism 100: first projection lattice

101: second projection lattice 102: third projection lattice

103: projection optical system 104: dichroic coating prism

105: dichroic coating prism 106: dichroic coating prism

107: light path conversion specular reflection mirror 108: light path conversion specular reflection mirror

109: light path conversion specular reflection mirror 110: light receiving optical system

111: Camera 112: Light Path Conversion Specular Reflection Mirror

113: measurement object 114: transfer table

115: drive means of the transfer table 400: control module

410: motor driver 420: camera power supply

430: lighting power supply 440: LCD panel driver

500: central control unit 510: motor control board

520: Image board 530: Interface board

Claims (20)

A transfer table 114 on which the measurement object 113 may be installed; A light source 90 installed above or below the transfer table 114 to emit light; The first frequency band filter 91 and 550 having a wavelength of 600 nm or more, respectively, to filter only a specific band wavelength in the light of the light source 90.

A second frequency band filter 92 having a wavelength of 50 nm; First, second and third projection grids 100, 101, and 102 for generating a grating image by using light from the light source 90 filtered by the first and second frequency band filters 91 and 92, respectively. Wow; The first, second and third projection grids 100, 101, 102 are configured by LCD or DLP or LCOS, A projection unit (200) formed of a projection optical system through which the grid image generated by the first projection grid (100) is transmitted to assist in measuring a relative position of an object; The first dichroic prism 104 and 550 having a wavelength of 600 nm or more that filter only the monochromatic light from the light of the grid image projected by the projection unit 200, respectively.

A second dichroic coated prism 105 and a light path converting prism 106 of 50 nm wavelength; Light path converting means (107, 108, 109) for converting a light path of a grating image passing through the prisms (104, 105, 106); The grating is provided on one side of the projection unit 200 and includes an optical system 110 and a camera 111 to receive the grating image reflected from the measurement object 113, and is reflected from the measurement object 113. An image acquisition unit 300 which receives an image and acquires an image; Optical path converting means (112) for converting an optical path of the grating image received by the image acquisition unit (300); Phase shift projection type three-dimensional shape measurement apparatus using three LCD panels and dichroic mirrors, characterized in that configured to include. The method according to claim 1, The first and second frequency band filters 91 and 92 are Phase shift projection three-dimensional shape measurement apparatus using three LCD panels and dichroic mirrors, characterized in that the filter to filter the monochromatic light of 400nm to 900nm wavelength. The method according to claim 1, The first projection lattice 100, the second projection lattice 101, the third projection lattice 102, the optical path converting means 93, 94, 95, 107, 108, 109, A phase shift projection type three-dimensional shape measuring apparatus using three LCD panels and a dichroic mirror, characterized in that the image is shifted microscopic displacement by the LCD or DLP or LCOS. The method according to any one of claims 1 to 3, The projection unit 200, Phase shift projection three-dimensional using three LCD panels and a dichroic mirror, characterized in that located in the upper direction of the measurement object 113, and positioned in the range of 17 degrees to 30 degrees with respect to the vertical upward direction Shape measuring device. First, second, and third projection grids 100, 101, and 102 for generating a grating image using the light of the light source 90, respectively, to obtain a correction plane phase and an object phase of the measurement object 113. Wow; A projection unit 200 for obtaining a grid image for calculating a height of the measurement object 113 by transmitting the grid images generated by the first, second, and third projection grids 100, 101, and 102, respectively; ; It is installed on one side of the projection unit 200, and provided with a light path converting means 112, an optical system 110 and a camera 111 to receive the grid image reflected from the measurement object 113, the measurement An image acquisition unit 300 receiving a grid image reflected from the object 113 to acquire an image; A central controller 500 for calculating a height of an unwrapped object with respect to the obtained image; Phase shift projection type three-dimensional shape measurement apparatus using three LCD panels and dichroic mirrors, characterized in that configured to include. The method according to claim 5, The central control unit 500, After obtaining the bias size of the object using the correction plane phase acquired by the projection unit 200, the object phase is unwrapped, and the height of the object unwrapped using the correction plane phase of the projection unit 200. Phase shift projection type three-dimensional shape measuring apparatus using three LCD panels and a dichroic mirror, characterized in that for calculating the. The method according to claim 5 or 6, The first projection lattice 100, the second projection lattice 101, the third projection lattice 102, Three LCD panel using a dichroic mirror and a phase shift projection type three-dimensional shape measuring apparatus using a dichroic mirror characterized in that the image is shifted by the micro-displacement by the LCD or DLP or LCOS. The first frequency band filter 91 and 550 having a wavelength of 600 nm or more, respectively, to filter only the monochromatic light from the light of the light source 90.

First, second and third projections for generating a grating image using the light source 90 filtered by the second frequency band filter 92 having a wavelength of 50 nm and the third frequency band filter 93 having a wavelength of 500 nm or less, respectively. Optical path for converting the optical path of the grating image projected from the projection optical system through which the grating images generated by the gratings 100, 101, 102 and the first, second and third projection gratings 100, 101, 102 are transmitted A projection grid projection unit 200 including conversion means 107, 108, and 109; A measurement object transfer part including a transfer table 114 on which the measurement object 113 is placed and a driving means 115 of the transfer table for driving the transfer table 114; The grating is provided on one side of the projection unit 200 and includes an optical system 110 and a camera 111 to receive the grating image reflected from the measurement object 113, and is reflected from the measurement object 113. An image acquisition unit 300 which receives an image and acquires an image; A control module unit 400 for controlling operations of the projection grid projection unit 100 and the image acquisition unit 300; A central control unit 500 for controlling the control module unit 400 and calculating a height of an unwrapped object with respect to an image acquired by the image acquisition unit 300; Phase shift projection type three-dimensional shape measurement apparatus using three LCD panels and dichroic mirrors, characterized in that configured to include. The method according to claim 8, The first and second frequency band filters 113 and 123, Phase shift projection three-dimensional shape measurement apparatus using three LCD panels and dichroic mirrors, characterized in that the filter so that monochromatic light of 370 nanometers to 900 nanometers wavelength is projected. The method according to claim 8, The projection unit 200, Phase shift projection three-dimensional using three LCD panels and a dichroic mirror, characterized in that located in the upper direction of the measurement object 113, and positioned in the range of 17 degrees to 30 degrees with respect to the vertical upward direction Shape measuring device. The method according to claim 8, The first projection lattice 100, the second projection lattice 101, the second projection lattice 102, the optical path converting means (104, 105, 106), A phase shift projection type three-dimensional shape measuring apparatus using three LCD panels and a dichroic mirror, characterized in that the image is shifted microscopic displacement by the LCD or DLP or LCOS. The method according to claim 8, The control module unit 400, A motor driver 410 for driving the driving means 230 of the transfer table in the measurement object transfer part; A camera power supply unit 420 for supplying power to the camera 111 in the image acquisition unit 300; An illumination power supply device 430 for supplying power to the light source 90 in the projection grid projection unit 100; An LCD driver 440 for controlling the operation of the first, second, and third projection grids 100, 101, and 102 in the projection grid projection unit 100; Phase shift projection type three-dimensional shape measurement apparatus using three LCD panels and dichroic mirrors, characterized in that configured to include. The method according to any one of claims 8 to 12, The central control unit 500, After obtaining the bias size of the object using the correction plane phases obtained by the first and second projection units 116 and 126, the object phase is unwrapped and the correction plane phases of the projection unit 200 are used. Phase shift projection type three-dimensional shape measuring apparatus using three LCD panels and a dichroic mirror characterized in that to calculate the height of the unwrapped object. 14. The method of claim 13, The central control unit 500, A motor control board 510 for controlling the operation of the motor driver 410 in the control module unit 400; An image board 520 for processing an image obtained from the camera 320 in the image acquisition unit 300; An interface board 530 which interfaces with the camera power supply device 420, the lighting power supply device 430, and the ultrasonic motor driving driver 400 in the control module unit 400; Three LCD panel using a dichroic mirror and a phase shift projection type three-dimensional shape measuring apparatus using a dichroic mirror, characterized in that configured to include. The first projection grid 100, the second projection grid 101, and the third projection grid 102 are simultaneously irradiated onto the correction surface using the projection unit 200, and the frequency of the image obtained through the color camera 111 is obtained. A first step (ST11 to ST15) of separating and obtaining reference phases for the correction plane phase 1, the correction plane phase 2, and the correction plane phase 3; The first projection lattice 100, the second projection lattice 101, and the third projection lattice 102 are simultaneously irradiated onto the measurement object 113 using the projection unit 200, and the color camera 111 is irradiated. A second step (ST21 to ST25) of obtaining the reference phases for the object phase 1, the object phase 2, and the object phase 3 by separating the frequencies of the images obtained through the object phase; Using the obtained correction plane phase 1, object phase 1, correction plane phase 2, object phase 2, correction plane phase 3, object phase 3 to obtain the bias size of the object, unwrapped the object phase and the height of the unwrapped object Calculating a third step (ST31 to ST34); Phase shift projection three-dimensional shape measurement method using three LCD panels and dichroic mirrors, characterized in that carried out including. The method according to claim 15, The first step (ST11 ~ ST15), A twelfth step (ST12) of irradiating the first projection lattice (100), the second projection lattice (101) and the third projection lattice (102) simultaneously on the correction surface using the projection unit (200); A thirteenth step (ST13) of acquiring an image while simultaneously moving the first projection grid (100), the second projection grid (101), and the third projection grid (102) by using the projection unit (200); The grid pattern image obtained by the camera 111 is separated into three primary colors of red, green, and blue, and then the moving image of the center wavelength 640 nm is applied to the bucket algorithm, and the moving image of the center wavelength 550 nm is applied to the bucket algorithm. A fourteenth and fifteenth steps ST14 and ST15 applying a 470 nm moving image to the bucket algorithm; The reference phase for the correction plane phase 1 is obtained by applying the bucket algorithm of the fourteenth step, the reference phase for the correction plane phase 2 is obtained by the bucket algorithm application, and the correction phase for the correction plane phase 3 is applied by the bucket algorithm application. A sixteenth step of obtaining a reference phase (ST16); Phase shift projection three-dimensional shape measurement method using three LCD panels and dichroic mirrors, characterized in that carried out including. 18. The method of claim 16, The fourteenth step, Phase shift projection three-dimensional shape measurement method using three LCD panel and dichroic mirror, characterized by applying one of three bucket, four bucket, five bucket, seven bucket algorithm. The method according to claim 15, The second step (ST21 ~ ST26), A twenty-second step (ST22) of irradiating a first projection grid (100), a second projection grid (101), and a third projection grid (102) simultaneously on the measurement object (113) by using the projection unit (200); A twenty-third step (ST23) of acquiring an image while simultaneously moving the first projection lattice (100), the second projection lattice (101) and the third projection lattice (102) image; The grid pattern image obtained by the camera 111 is separated into three primary colors of red, green, and blue, and then the moving image of the center wavelength 640 nm is applied to the bucket algorithm, and the moving image of the center wavelength 550 nm is applied to the bucket algorithm. 24th and 25th steps ST24 and ST25 applying a 470 nm moving image to the bucket algorithm; The reference phase for object phase 1 is obtained by applying the bucket algorithm of the twenty-fourth step, the reference phase for object phase 2 is obtained by applying the bucket algorithm, and the reference phase for object phase 3 is applied by applying the bucket algorithm. Obtaining a twenty sixth step (ST26); Phase shift projection three-dimensional shape measurement method using three LCD panels and dichroic mirrors, characterized in that carried out including. 19. The method of claim 18, The twenty-fourth step, Phase shift projection three-dimensional shape measurement method using three LCD panel and dichroic mirror, characterized by applying one of three bucket, four bucket, five bucket, seven bucket algorithm. The method according to any one of claims 15 to 19, The third step (ST31 ~ ST34), A thirty-first step (ST31) of obtaining a bias magnitude using the correction plane phase 3 of the first step and the object phase 3 of the second step; A thirty-second step (ST32) of unbiasing the object phases 1 and 2 of the second step by using the bias magnitude obtained in the thirty-first step; A step 33 (ST33) of unwrapping the object phases 1 and 2 unbiased in the 32nd step; A thirty-fourth step (ST34) of calculating the height of the measurement target 240 using the correction plane phase 1 of the first step with respect to the object phase 1 unwrapped in the thirty-third step; Phase shift projection three-dimensional shape measurement method using three LCD panels and dichroic mirrors, characterized in that carried out including.

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