JP5146636B2 - Height measuring device - Google Patents

Description

  The present invention relates to a method of generating a plurality of light beams and condensing them on a measurement object, and measuring the height of each part on the measurement object based on the brightness of the reflected light. The present invention relates to a height measuring method and a height measuring apparatus which are intended to measure the height of each part on the object to be measured in a short time.

  Conventionally, for a defect such as a foreign object on the object to be measured, a pattern of a captured image is compared with a design pattern or a captured peripheral pattern, and different parts are captured to determine whether there is an abnormality. However, in this case, since height information cannot be acquired, for example, a defect such as a protrusion cannot be recognized.

Therefore, in order to solve such a problem, it is arranged in an optically conjugate relationship with the focal position of the objective lens of the microscope that focuses the light beam on the object to be measured, and a plurality of micromirrors are arranged in a matrix. By tilting the micro mirror of the measurement point selecting means, the light beam from the light source is reflected in the direction of the object to be measured, and the light beam reflected by the micro mirror is condensed on the object to be measured by the objective lens. The reflected and scattered light from the condensing point of the light beam collected on the object to be measured is detected through the micro mirror of the measuring point selecting means, and the object to be measured and the objective lens are relatively positioned in the optical axis direction. The movement amount indicating the peak luminance value from the brightness of the light detected through the micromirror and the detected movement amount data is the height of the measurement point of the object to be measured. I'll ask for There is a height measurement method (e.g., see Patent Document 1).

However, in such a conventional height measuring method, when the object to be measured has a large area, the microscope or the object to be measured is moved stepwise in the two-dimensional plane of XY for each predetermined region. As described above, the object to be measured and the objective lens of the microscope must be moved relative to each other in the direction of the optical axis of the objective lens , and the measurement takes a long time.

  Therefore, the present invention provides a height measuring method and a height measuring apparatus that address such problems and perform a height measurement of each part on a large-area measurement object in a short time. Objective.

In order to achieve the above object, according to the height measuring method of the present invention, a plurality of beam light generating units for conveying a measured object in a certain direction by a conveying means and receiving light from a light source to generate beam light are provided. The optical distance between the beam light generators in each row intersecting the transport direction and the upper surface of the transport means is arranged in a matrix along the transport direction of the object to be measured and the direction intersecting the transport direction. A plurality of rows of light beams intersecting the transport direction are generated by the light beam irradiation means made different from each other and irradiated toward the object to be measured, and the optical axis is orthogonal to the upper surface of the transport means. The condensing optical system provided by each of the plurality of light beams is condensed at different height positions in the vicinity of the surface of the object to be measured for each row, the light beams of each row intersecting the transport direction, Said irradiated by each beam light in each row The brightness of reflected light from each measurement point on the measurement object is detected by the light detection means, and the same measurement point is obtained by transporting the measurement object from the plurality of brightnesses detected by the light detection means. Are extracted at each measurement point for a plurality of luminances obtained by irradiating with the beam light of each row at different timings, and the peak luminance of the reflected light at each measurement point is calculated based on the extracted plurality of luminances The height of each measurement point is obtained from each peak luminance.

In addition, the height measuring apparatus according to the present invention is equipped with a conveying means for placing an object to be measured and conveying it in a fixed direction, and disposed above the conveying means, and receives light from a light source to generate beam light. A plurality of beam light generators are arranged in a matrix along the transport direction of the object to be measured and the direction intersecting the transport direction, and the beams in each row intersecting the transport direction among the plurality of beam light generators The optical distance between the light generation unit and the upper surface of the transport means is different for each column, and a plurality of rows of beam light that intersect the transport direction are generated and irradiated to the object to be measured. Each of the light beams generated by the plurality of light beam generators is disposed between the irradiation unit, the transport unit, and the beam light irradiation unit with an optical axis orthogonal to the upper surface of the transport unit. Different heights near the surface of the object to be measured for each row A condensing optical system for condensing the light beam on the device, and a plurality of light receiving elements corresponding to each light beam generating portion of the light beam irradiation means, on the object to be measured irradiated by each light beam in each row The light detection means for detecting the brightness of the reflected light from each measurement point of the light by the light receiving element and the same measurement by transporting the object to be measured out of the plurality of brightnesses detected by the light detection means A plurality of luminances obtained by irradiating points at different timings with the beam light of each row are extracted for each measurement point, and the peak luminance of reflected light at each measurement point is calculated based on the extracted plurality of luminances And a control means for obtaining the height of each measurement point from each peak luminance.

With such a configuration, a plurality of beam light generators that place the object to be measured by the transport unit and transport it in a certain direction, and are disposed above the transport unit and receive light from the light source to generate beam light. Are arranged in a matrix along the transport direction of the object to be measured and the direction intersecting the transport direction, and the upper surfaces of the beam light generation units and the transport means of each row intersecting the transport direction among the plurality of beam light generation units A plurality of rows of light beams intersecting the transport direction are generated by the light beam irradiation means whose optical distance between them is different for each row , and is irradiated toward the object to be measured . Each beam light generated by the plurality of beam light generation units is condensed at different height positions in the vicinity of the surface of the object to be measured for each column by a condensing optical system arranged with orthogonal optical axes. Provided with a plurality of light receiving elements corresponding to each beam light generating part of the light irradiation means The brightness of the reflected light from each measurement point on the object to be measured irradiated by each light beam of each row is detected by the light receiving element of the light detecting means, and the control means detects the brightness of the plurality of brightnesses Then, a plurality of luminances obtained by irradiating the same object to be measured at different timings by the beam light of each row by transporting the object to be measured are extracted for each measuring point, and the extracted plurality of luminances are obtained. Based on this, the peak luminance of the reflected light at each measurement point is calculated, and the height of each measurement point is obtained from the peak luminance.

  Further, the beam light generation part of the beam light irradiation means is a micromirror formed to be individually tiltable. As a result, the light beam is generated by the micromirror formed so as to be individually tiltable.

  Further, the beam light irradiation means is provided to be inclined at a predetermined angle in the transport direction with respect to the upper surface of the object to be measured. Accordingly, the beam light irradiating means is provided to be inclined at a predetermined angle in the transport direction with respect to the upper surface of the object to be measured, so that among the plurality of beam light generators, the beam light generators in each row intersecting the transport direction And the distance between the upper surface of the conveying means is varied for each column.

  The condensing optical system is a telecentric optical system. Thereby, each beam light generated by the plurality of beam light generation units of the beam light irradiation means in the telecentric optical system is condensed at different height positions near the surface of the object to be measured for each column.

According to the height measuring method of the first aspect, the height of each part on the measured object can be measured only by conveying the measured object in one direction. Therefore, as in the prior art, the microscope or object to be measured is stepped in the two-dimensional plane of XY, and the object to be measured and the objective lens of the microscope are relatively moved in the optical axis direction of the objective lens for each predetermined region. Since it is not necessary to move, the height measurement of each part on the to-be-measured object of a large area can be performed in a short time. In this case, when the irradiation area of the plurality of rows of beam light by the beam light irradiation means is narrower than the width in the direction intersecting the conveyance direction of the object to be measured, the condensing optical system, the beam light irradiation means, the light source, and the light detection means It is possible to measure the height of the entire surface of the object to be measured by the same method as described above only by arranging a plurality of optical systems including the above in a direction intersecting the conveyance direction of the object to be measured.

Moreover, according to the height measuring apparatus which concerns on Claim 2, the height of each part on a to-be-measured object can be measured only by conveying a to-be-measured object to one direction. Therefore, as in the prior art, the microscope or object to be measured is stepped in the two-dimensional plane of XY, and the object to be measured and the objective lens of the microscope are relatively moved in the optical axis direction of the objective lens for each predetermined region. Since it is not necessary to move, the height measurement of each part on the to-be-measured object of a large area can be performed in a short time. In this case, when the irradiation area of the plurality of rows of beam light by the beam light irradiation means is narrower than the width in the direction intersecting the conveyance direction of the object to be measured, the condensing optical system, the beam light irradiation means, the light source, and the light detection means It is possible to measure the height of the entire surface of the object to be measured by the same method as described above only by arranging a plurality of optical systems including the above in a direction intersecting the conveyance direction of the object to be measured. Further, since the drive mechanism is only a mechanism for conveying the object to be measured in one direction, the configuration of the apparatus is simplified.

  Furthermore, according to the third aspect of the invention, a predetermined micromirror can be selected and tilted, and the measurement point on the object to be measured can be easily selected.

  Furthermore, according to the invention of claim 4, by changing the inclination angle of the light beam irradiation means with respect to the upper surface of the object to be measured, the beam from each beam light generating section in each row intersecting the transport direction of the object to be measured. The light collection height position can be easily adjusted. Thereby, it is possible to easily adjust the resolution of the height measurement.

  According to the fifth aspect of the present invention, the distance between each beam light generating portion of the beam light irradiation means and the upper surface of the transport means changes, and the irradiation position of each beam light on the object to be measured changes. do not do. Therefore, even when the resolution of height measurement is adjusted by changing the distance between the light beam generating section in each row and the upper surface of the conveying means, the adjustment can be performed more easily.

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a schematic view showing an embodiment of a height measuring apparatus according to the present invention. This height measuring device generates a plurality of light beams and condenses them on the object to be measured, and measures the height of each part on the object to be measured from the brightness of the reflected light. a light source 2, a digital micromirror device (hereinafter referred to as "DMD" (Texas Instruments trademark)) and 3, the focusing optical system 4, comprises a light detecting unit 5, and a control unit 6 configured Has been . Hereinafter, a case where the object to be measured is a color filter substrate will be described.

  The conveying means 1 carries the color filter substrate 7 and conveys it in the direction indicated by the arrow A, and the stage 8 is moved at a predetermined speed by a driving means combining a motor, a gear, etc. (not shown). Can be done. Further, the conveyance means 1 is provided with a speed sensor and a position detection sensor (not shown), and outputs stage moving speed information and position information to the control means 6 described later.

  A light source 2 is disposed above the conveying means 1. The light source 2 emits light for generating beam light for irradiating the color filter substrate, and is a laser oscillator, for example. The light source 2 is configured by combining a plurality of laser light sources having different wavelengths so that the light source 2 can be selected by switching with a switch according to the background color of the measurement point of the measurement object placed on the upper surface of the stage 8. Also good. Further, the light emitted from the light source 2 is expanded in diameter by the beam expander 9 and is emitted as parallel light by the collimator lens 10.

  A DMD 3 is disposed in front of the emission direction of the light emitted from the light source 2. The DMD 3 receives a plurality of micromirrors 11 serving as a light beam generating unit that receives light from the light source 2 and generates a light beam. The direction of the color filter substrate 7 is transported (in the direction of arrow A in FIG. 1) They are arranged in a matrix along the intersecting direction and serve as beam light irradiation means. And the distance between the micromirror 11 of each row | line | column which cross | intersects the said conveyance direction among several micromirrors 11, and the upper surface of the stage 8 of the conveyance means 1 is made to differ for every row | line | column.

Specifically, in the DMD 3, as shown in FIG. 1, the distance from the upper surface of the stage 8 of the conveying means 1 is a position where the end on the near side in the conveying direction indicated by arrow A is farther than the end on the front side. As described above, it is arranged to be inclined at a predetermined angle in the transport direction with respect to the upper surface of the stage 8 of the transport means 1. Thereby, the optical distance between the micromirrors 11 in each row intersecting the transport direction and the upper surface of the stage 8 of the transport means 1 is different for each row.

  Each of the micromirrors 11 is individually tilted so as to reflect the light from the light source 2 toward the color filter substrate 7 as indicated by a solid line in FIG. Hereinafter, this state is referred to as “on state” of the micromirror 11. On the other hand, when the micromirror 11 is in the “off state”, the micromirror 11 is tilted as shown by a broken line in the drawing, and reflects the light beam from the light source 2 in a direction different from the direction of the color filter substrate 7. . The reflected light is absorbed by a light absorber (not shown).

  The micromirror 11 can be formed to have a size of, for example, about 16 μm square, and the micromirror 11 can generate beam light having a cross-sectional shape substantially the same as that. Further, the micromirror 11 acts as a pinhole for the light reflected and returned from the color filter substrate 7.

A condensing optical system 4 is disposed between the conveying means 1 and the DMD 3. The condensing optical system 4 condenses a plurality of rows of light beams generated by the micromirrors 11 of the DMD 3 at different height positions near the surface of the color filter substrate 7 for each row that intersects the transport direction. Yes, it is a telecentric optical system.

FIG. 3 is an explanatory diagram showing a state in which each light beam irradiated from the DMD 3 toward the color filter substrate 7 is condensed at different height positions for each column by the condensing optical system 4. In the figure, in the portion above the broken line, the light from the light source 2 is reflected by the DMD 3 toward the condensing optical system 4 side, and the light from the direction of the condensing optical system 4 is directed to the light detection means 5 by the DMD 3. Shows the reflected state. Further, in the portion below the break line, the light emitted from the condensing optical system 4 is condensed near the surface of the color filter substrate 7, and the light reflected by the color filter substrate 7 is condensed. It shows a state of returning to the side, and is shown at a larger magnification than the upper part of the break line. In the micromirrors 11 in each row of the DMD 3, as shown in the figure, for example, if the micromirror rows 11a, 11b, 11c, and 11d are in order of decreasing optical distance from the upper surface of the color filter substrate 7, the micromirror rows 11a to 11d are arranged. Each beam light generated by 11d is condensed at a different height position for each column according to the optical distance from the surface of the color filter substrate 7 of each micromirror column 11a to 11d. In FIG. 3, the beam light generated in the micromirror array 11a is collected in the plane 13a on the color filter 12 of the color filter substrate 7, and the beam light from the micromirror array 11b is collected in the plane 13b. It shows a case where the beam light from the micromirror array 11c is collected in the plane 13c and the beam light from the micromirror array 11d is collected in the plane 13d. And the space | interval z of each plane becomes resolution | decomposability of height measurement. In the figure, reference numeral 14 denotes a black matrix, and reference numeral 15 denotes a protrusion generated on the surface of the color filter substrate 7.

  Table 1 shows an example of the configuration of the DMD 3 applied to this embodiment. This DMD 3 is a micromirror 11 having a size of 13.6 μm arranged in a matrix of 768 vertically and 1024 horizontally at an array pitch a of 14 μm, and the angle θ with respect to the upper surface of the color filter substrate 7 is 24 degrees. It is provided so as to be inclined in the transport direction. Thereby, the inclination pitch b of the micromirror 11 becomes 12.79 μm, and the Z pitch c in the height direction of the micromirror 11 becomes 5.69 μm. The effective size of the micromirror 11 viewed from the color filter substrate 7 side is 12.42 μm. In FIG. 3, among the plurality of micromirrors 11 that are turned on, the transport direction is shown at two pitch intervals, but the reflected light adjacent to the reflected light from the color filter substrate 7 is DMD 3 surface. In fact, as shown in Table 1, it is driven at intervals of every 5 pitches. Therefore, the interval between the drive micromirrors 11 adjacent in the transport direction is 63.95 μm.

  Table 2 shows the condensing state of each light beam from the DMD 3 when the condensing optical system 4 having a magnification of 10 is used. According to this, the distance x between the beam spot rows by the light beams of each row irradiated on the color filter substrate 7 is 6.39 μm, the height z of the plane in which the light beams are collected is 0.28 μm, and the light beam The beam spot size w at the condensing point is 1.24 μm, and the Z scan width (difference between the highest position and the lowest position of the condensing height of the micromirror 11) is 58.31 μm.

  A light detecting means 5 is provided on the optical path where the optical path from the DMD 3 to the light source 2 is branched by the half mirror 16 between the light source 2 and the DMD 3. This light detection means 5 detects the brightness of the reflected light from each measurement point on the color filter substrate 7 irradiated by each beam light in each row, and corresponds to each micromirror 11 of the DMD 3. The two-dimensional imaging camera is provided with a plurality of light receiving elements (hereinafter referred to as “pixels”), and an image of the mirror surface of the DMD 3 is formed on the pixels by the relay lens 17.

  When the color filter substrate 7 has a large area, the condensing optical system 4, DMD 3, light source 2, and light detection means 5 are taken as a set in a direction that intersects the transport direction of the color filter substrate 7. A plurality of sets may be arranged side by side.

  Control means 6 is provided in connection with the transport means 1, DMD 3, and light detection means 5. This control means 6 is obtained by irradiating the same measurement point with the beam light of each column at different timings by transporting the color filter substrate 7 from among the plurality of luminances detected by the light detection means 5. A plurality of brightnesses are extracted for each measurement point, the peak brightness of the reflected light at each measurement point is calculated based on the extracted brightnesses, and the height of each measurement point is obtained from these peak brightnesses. Yes, as shown in FIG. 4, a transport unit drive controller 18, a DMD drive controller 19, an image processing unit 20, a memory 21, a calculation unit 22, and a control unit 23 are provided.

  The conveying means drive controller 18 controls the moving direction and moving speed of the stage 8 of the conveying means 1. The DMD drive controller 19 selectively drives a predetermined micromirror 11. Further, the image processing unit 20 is on the color filter substrate 7 detected by the light detection means 5 via the micromirrors 11 of the micromirror rows 11a to 11d that are turned on among the plurality of micromirrors 11 of the DMD 3. The brightness of the reflected light from the plurality of measurement points is processed at a predetermined timing to generate brightness data corresponding to each measurement point, and is acquired via the micromirror rows 11a to 11d based on the brightness data. Image data of a plurality of two-dimensional images. The memory 21 stores the dimensions described in Tables 1 and 2 in advance, and temporarily stores the luminance data generated by the image processing unit 20, a plurality of two-dimensional image data, and the like. is there. Further, the calculation unit 22 acquires the plurality of two-dimensional image acquisition timings based on the conveyance speed of the color filter substrate 7 input from the conveyance unit 1 and the beam spot row interval x (see FIG. 3) read from the memory 21. The time interval t (see FIG. 6) is calculated, and the peak brightness of the reflected light at each measurement point is calculated based on the brightness of the plurality of reflected lights detected at different timings for each measurement point. The height of each measurement point is calculated. And the said control part 23 controls the process timing of the image process part 20, and the same measurement point is each set by the color filter board | substrate 7 being conveyed among several brightness | luminances detected by the light detection means 5. A plurality of luminances obtained by irradiating at different timings with the beam light of the row are extracted for each measurement point, and controlled so that each of the above components is appropriately driven.

Next, a height measuring method performed using the height measuring apparatus configured as described above will be described with reference to the flowchart of FIG.
First, initial setting is performed by operating an input means (not shown). This initial setting is, for example, the conveyance speed V of the color filter substrate 7, the driving pattern of the micromirror 11 of the DMD 3, the conveyance direction of the color filter substrate 7, and the driving interval of the micromirror 11 in the direction intersecting the conveyance direction. The inputted data is stored in the memory 21 of the control means 6.

  In step S1, the stage 8 of the transport unit 1 starts moving under the control of the transport unit drive controller 18 of the control unit 6 by turning on the start switch (not shown), and the color filter substrate 7 placed on the stage 8 is started. Is conveyed at a set speed V in the direction of arrow A in FIG. At the same time, the micromirror 11 of the DMD 3 is turned on according to the input drive pattern.

  In step S2, a plurality of light beams arranged in a matrix are generated by the DMD 3 in response to the light beam from the light source 2. Then, as shown in FIG. 3, the plurality of light beams are irradiated onto the color filter substrate 7 by the condensing optical system 4, and in the planes 13 a to 13 d having different heights for each row intersecting the transport direction. Focused.

  In step S <b> 3, the reflected light from each measurement point irradiated with each beam light on the color filter substrate 7 enters the light detection means 5 via the corresponding micromirror 11, and the light corresponding to each micromirror 11. The brightness of each reflected light is detected by each pixel of the detection means 5. This luminance is A / D converted at a predetermined timing in the image processing unit 20 and converted into luminance data of each measurement point on the color filter substrate 7.

In this case, since the color filter substrate 7 is transported at a speed V in the direction of arrow A in FIG. 1, for example, FIG. 6A acquired through each of the micromirror rows 11 a to 11 d intersecting the transport direction. The surface image of the color filter substrate 7 shown is a two-dimensional image as shown in FIGS. Specifically, the acquisition of two-dimensional image of FIG. 6 (b) is started at time t ₁ by a micro mirror array 11a. Further, the acquisition of two-dimensional image of FIG. (C) is started at time t ₂ by a micro-mirror array 11b. Moreover, the acquisition of two-dimensional image of FIG. (D) is started at time t ₃ by the micro mirror array 11c. The acquisition of two-dimensional image of FIG. (E) is started at time t ₄ by a micro mirror array 11d. Further, since the beam spot row interval is x as shown in FIG. 3, when the conveyance speed of the color filter substrate 7 is V, each of the two-dimensional images is acquired at a time interval of t = x / V. It will be.

  Therefore, in step S4, based on the luminance data acquired via the micromirror rows 11a to 11d, the image processing unit 20 uses the plurality of two-dimensional images (four two-dimensional images in FIG. 6). Image data is generated.

  Here, the light beam generated by the micromirror array 11a is condensed on the plane 13a on the color filter substrate 7 as shown in FIG. 3, so that the light beam on the color filter substrate 7 as shown in FIG. 6B. The brightness of the reflected light reflected by the flat surface 13a and detected through the micromirror array 11a is increased. On the other hand, since the spot size of the light beam spreads at the protrusion 15 on the color filter substrate 7, the brightness of the reflected light reflected by the protrusion 15 and detected through the micromirror array 11a is lowered. In particular, the brightness of the reflected light at the protrusion 15 decreases as the reflection position increases. For example, when the luminance is classified into four levels of “4”, “3”, “2”, and “1” from high luminance to low luminance, the luminance in the two-dimensional image of FIG. The flat surface 13 a on the color filter substrate 7 is the highest at “4” around 15, the area near the skirt of the protrusion 15 is slightly higher at “3”, the middle of the protrusion 15 is slightly lower at “2”, and the protrusion The top of the portion 15 is the lowest at “1”.

  Further, as shown in FIG. 3, the light beam generated by the micromirror array 11b is condensed in a plane 13b higher than the plane 13a on the color filter substrate 7 by z. Therefore, as shown in FIG. 6C, the brightness of the reflected light that is reflected at the height position substantially equal to the plane 13b and acquired through the micromirror array 11b is increased, but other height positions are obtained. The brightness of the reflected light reflected by and acquired through the micromirror array 11b is lowered. In particular, the greater the amount of deviation from the plane 13b in the height direction, the greater the reduction in the brightness of the reflected light. For example, when the luminance is displayed in the above four steps, in the two-dimensional image of FIG. 6C, the luminance is “3” on the plane 13a on the color filter substrate 7 around the protrusion 15 and near the base of the protrusion 15. Is “4”, the middle of the protrusion 15 is “3”, and the top of the protrusion 15 is “2”.

  Furthermore, as shown in FIG. 3, the light beam generated by the micromirror array 11c is collected in a plane 13c that is 2z higher than the plane 13a on the color filter substrate 7. Therefore, as shown in FIG. 6D, the brightness of the reflected light that is reflected at the height position substantially equivalent to the plane 13c and acquired through the micromirror array 11c is increased, but other height positions are obtained. The brightness of the reflected light reflected by and acquired through the micromirror array 11c is lowered. In particular, the greater the deviation from the plane 13c in the height direction, the greater the reduction in the brightness of the reflected light. For example, similarly to the above, when the luminance is displayed in the above four steps, in the two-dimensional image of FIG. 6D, the luminance is “2” on the plane 13a on the color filter substrate 7 around the protrusion 15 and the protrusion. The vicinity of the base of the portion 15 is “3”, the middle of the protrusion 15 is “4”, and the top of the protrusion 15 is “3”.

  Then, as shown in FIG. 3, the beam light generated by the micromirror array 11d is condensed in a plane 13d that is 3z higher than the surface 13a of the color filter substrate 7. Therefore, as shown in FIG. 6 (e), the brightness of the reflected light that is reflected at the height position substantially equal to the plane 13d and acquired through the micromirror array 11d is increased, but other height positions are obtained. The brightness of the reflected light reflected by and acquired through the micromirror array 11d is lowered. In particular, the greater the amount of deviation from the plane 13d in the height direction, the greater the decrease in the brightness of the reflected light. For example, as described above, when the luminance is displayed in the above four steps, the luminance in the two-dimensional image of FIG. 6E is “1” on the plane 13a on the color filter substrate 7 around the protrusion 15 and the protrusion. The vicinity of the base of the portion 15 is “2”, the middle of the protrusion 15 is “3”, and the top of the protrusion 15 is “4”.

  As described above, the image data of the two-dimensional images captured through the respective micromirror rows 11a to 11d and including the luminance information and the height information shown in FIGS. 6B to 6E are stored in the memory 21, respectively. The

In step S5, the image data of, for example, four two-dimensional images shown in FIGS. 6B to 6E are read from the memory 21 to the control unit 23. Then, the four two-dimensional images are overlaid by the control unit 23 with the XYZ coordinate axes aligned as shown in FIG. 7A and acquired at different timings for each of a plurality of measurement points on the color filter substrate 7. A plurality of luminance data is extracted. For example, as shown in FIG. 7A, luminance data I ₁ , I ₂ , I ₃ , and I ₄ corresponding to the same measurement point P are extracted from _four two-dimensional images.

In step S6, based on the height information of the four two-dimensional images and the extracted plurality of luminance data I _{1 to} I ₄ in the calculation unit 22, as shown in FIG. peak luminance I _P is calculated for each measurement point by interpolation processing.

In step S7, the height z _P indicating the calculated peak intensity I _P at each measurement point in the calculating portion 22 is calculated. These height data are stored in the memory 21 together with the XY coordinate data of each measurement point.

  In step S8, the height data and XY coordinate data of each measurement point are read from the memory 21, and for example, three-dimensionally displayed on a display unit (not shown) as shown in FIG. 7B.

  In the above embodiment, the case where the object to be measured is the color filter substrate 7 has been described. However, the present invention is not limited to this and may be any type.

  In the above embodiment, the case where the DMD 3 is disposed to be inclined at a predetermined angle in the transport direction with respect to the upper surface of the transport unit 1 has been described. Mirror rows may be arranged on the stairs.

  In the above description, the case where the light beam generation unit is the micromirror 11 has been described. However, the present invention is not limited to this and may be a pinhole, or may be a pixel of a liquid crystal display element or a nonlinear optical device. An optical switch made of a crystal may be used.

It is a schematic diagram which shows embodiment of the height measuring apparatus by this invention. It is explanatory drawing which shows the ON / OFF state of the micromirror of DMD used for the said height measuring apparatus. It is explanatory drawing which shows the state by which each beam light irradiated toward the color filter board | substrate from said DMD is condensed at a different height position for every row | line | column with a condensing optical system. It is a block diagram which shows the structural example of the control means of the said height measuring apparatus. It is a flowchart which shows the procedure of the height measuring method performed using the said height measuring apparatus. It is explanatory drawing which shows the several two-dimensional image imaged through each micro mirror row | line | column of said DMD. It is explanatory drawing which shows the example which extracts the several brightness | luminance data acquired at the different timing from the same measurement point by the said several two-dimensional image, and the example of a display of a height measurement result. It is a graph explaining the calculation of the height performed using the some luminance data corresponding to the same measurement point in the said several two-dimensional image.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Conveyance means 2 ... Light source 3 ... DMD (beam light irradiation means)
4 ... Condensing optical system 5 ... Light detection means 6 ... Control means 7 ... Color filter substrate (object to be measured)
11 ... Micromirror (beam light generator)
11a to 11d: micro mirror array

Claims (5)

Transport the object to be measured in a certain direction by the transport means,
A plurality of beam light generators that receive light from a light source and generate beam light are arranged in a matrix along the transport direction of the object to be measured and the direction intersecting the transport direction, and each intersecting the transport direction A plurality of rows of light beams intersecting the transport direction are generated by the light beam irradiation means in which the optical distance between the light beam generators of the rows and the upper surface of the transport means is different for each row , and the measurement target Irradiate the object,
By means of a condensing optical system provided with the optical axis orthogonal to the upper surface of the conveying means, the beam light of each column that intersects the conveying direction among the plurality of beam light is Condensing at different heights near the surface,
The light detection means detects the brightness of the reflected light from each measurement point on the measurement object irradiated by each beam light in each row,
Among the plurality of luminances detected by the light detection means, a plurality of luminances obtained by irradiating the same object to be measured at different timings with the beam light of each row by conveying the object to be measured. Extract every measurement point,
Calculate the peak luminance of the reflected light at each measurement point based on the plurality of extracted luminance,
Obtain the height of each measurement point by each peak luminance,
A height measuring method characterized by the above. Conveying means for placing the object to be measured and conveying it in a certain direction;
A plurality of beam light generators that are disposed above the transport means and generate light beams upon receiving light from a light source are arranged in a matrix along the transport direction of the object to be measured and the direction intersecting the transport direction. An optical distance between each of the plurality of beam light generation units intersecting the conveyance direction among the plurality of beam light generation units and the upper surface of the conveyance unit is different for each column , and the conveyance direction Beam light irradiating means for generating a plurality of intersecting beams and irradiating the object to be measured ;
Between the transport means and the beam light irradiation means, an optical axis is arranged orthogonal to the upper surface of the transport means, and each light beam generated by the plurality of light beam generation units is arranged for each column. A condensing optical system for condensing at different height positions near the surface of the object to be measured;
A plurality of light receiving elements are provided corresponding to each light beam generating portion of the light beam irradiation means, and the brightness of reflected light from each measurement point on the object to be measured irradiated by each light beam in each column is determined. Light detecting means for detecting by the light receiving element;
Among the plurality of luminances detected by the light detection means, a plurality of luminances obtained by irradiating the same object to be measured at different timings with the beam light of each row by conveying the object to be measured. Control means for extracting for each measurement point, calculating the peak luminance of the reflected light at each measurement point based on the extracted plurality of luminances, and obtaining the height of each measurement point by the respective peak luminances;
A height measuring device comprising:   3. The height measuring apparatus according to claim 2, wherein the light beam generating portion of the light beam irradiation means is a micromirror formed to be individually tiltable.   The height measuring apparatus according to claim 2 or 3, wherein the beam light irradiation means is provided to be inclined at a predetermined angle in the transport direction with respect to the upper surface of the object to be measured.   The height measuring device according to claim 2, wherein the condensing optical system is a telecentric optical system.

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