JP2005114708A - Optical displacement meter and method for measuring applied cross section area of viscous fluid using same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To measure a relatively accurate applied cross section area even if displacement data can not be accurately obtained near a slope in a rising part when an optical displacement meter measures the applied cross section area of a viscous fluid. <P>SOLUTION: A light is focused by an objective lens 15 and projected to a measured object 16. The reflected light is received through the objective lens 15 and a pinhole 17a. While the objective lens 15 is vibrated in the optical axis direction and its location is detected, a displacement of the surface of the measured object 16 is measured on the basis of the location information of the objective lens 15 having the maximum quantity of the received light. An optical displacement meter is provided with a displacement data storage 41 for storing the displacement data of the surface of the measured object 16 obtained while the measured object 16 is moved relative to the optical axis of the objective lens 15 by the predetermined distance, a height/width calculating part 42 for calculating a height and a width corresponding to the maximum rising part defined by the displacement data, and a cross section calculating part 43 for calculating the cross section of the rising part on the basis of the height and the width. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention is an optical displacement meter that projects light onto a measurement object, receives the reflected light and measures the displacement of the surface of the measurement object, and uses it to determine the amount of viscous liquid such as a sealant applied. It relates to a measuring method.

  As an optical displacement meter, a focus detection type non-contact displacement meter as described in Patent Document 1 has been put into practical use. This optical displacement meter can measure a change (displacement) in the height of the surface of a measurement object on the order of microns using a laser beam. The configuration will be briefly described below.

  FIG. 1 is a block diagram showing the configuration of a conventional optical displacement meter. The laser light emitted from the laser diode 12 driven by the laser power control circuit 11 sequentially passes through the beam splitter 13, the collimator lens 14, and the objective lens 15 and is projected onto the measurement object 16. The reflected light from the measurement object 16 is reflected by the beam splitter 13 through the objective lens 15 and the collimator lens 14, and enters the photodiode 18 through the pinhole 17 a of the optical diaphragm 17. An electric signal corresponding to the amount of received light obtained by photoelectric conversion by the photodiode 18 is amplified by the amplifier 19 and then input to the arithmetic unit 20.

  The objective lens 15 is attached to a U-shaped tuning fork 21. When the tuning fork 21 vibrates, the objective lens 15 vibrates in the optical axis direction. The tuning fork 21 is vibrated at a constant frequency and amplitude (for example, 800 Hz, ± 0.3 mm) by a solenoid 24 excited by a tuning fork amplitude control circuit 25. A tuning fork amplitude detector 22 is arranged on the side of the tip of the tuning fork 21, and the detection signal (sine wave signal) is fed back to the arithmetic unit 20 through the amplifier 23.

  When the solenoid 24 is excited by the tuning fork amplitude control circuit 25 and the objective lens 15 vibrates in the optical axis direction due to the vibration of the tuning fork 21, the measurement object passes from the laser diode 12 through the beam splitter 13, the collimator lens 14, and the objective lens 15. The focal point of the laser beam projected onto 16 (that is, the focal point of the objective lens 15) vibrates in the optical axis direction. As a result, the laser beam reflected on the surface of the measurement object 16, passes through the objective lens 15 and the collimator lens 14, is reflected by the beam splitter 13, passes through the pinhole 17 a of the optical diaphragm 17, and enters the photodiode 18. The amount of light changes.

  That is, when the focal point of the laser beam projected onto the measurement object 16 is on the surface of the measurement object 16 (in a focused state), most of the reflected light reaching the optical aperture 17 is a pinhole. The amount of received laser light that passes through 17a and enters the photodiode 18 is maximized. On the other hand, when the focal point of the laser beam deviates from the surface of the measuring object 16, only a part of the reflected light that has reached the optical aperture 17 passes through the pinhole 17a and the rest is cut. As a result, the amount of light received by the photodiode 18 is rapidly reduced.

  Therefore, in the arithmetic unit 20, the position signal of the objective lens 15 is obtained from the sine wave signal from the tuning fork amplitude detector 22 when the amount of light received by the photodiode 18 becomes maximum, and this position signal is obtained by the distance conversion unit 26. By converting to, the displacement of the surface of the measurement object 16 can be obtained. The specific circuit configuration and operation of the arithmetic unit 20 are disclosed in detail in Patent Document 1.

  As an example of the measurement using the optical displacement meter as described above, measurement of the application cross-sectional area of a viscous liquid such as a sealing agent applied to a glass substrate or the like can be mentioned. For example, in the manufacturing process of a liquid crystal display, it is necessary to seal the periphery of two glass substrates facing in parallel at a predetermined interval via a spacer with a sealant. After applying the sealing agent along the peripheral part of one glass plate, the other glass plate is stacked and pressed to fix the two glass substrates at the peripheral part with an interval determined by the size of the spacer, Sealed.

  At this time, if the application amount of the sealing agent is too small, sealing (sealing) may be incomplete, and if it is too much, excess sealing agent may protrude from the peripheral portions of the two glass substrates. Therefore, it is necessary to strictly manage the coating amount of the sealing agent, that is, the coating cross-sectional area, and the coating cross-sectional area is measured for the management. There is a method disclosed in Patent Document 2 as a conventional example of a method for measuring the application cross-sectional area of such a viscous liquid. In this measurement method, the contour (height distribution) of the application cross section is obtained by processing the image obtained by the imaging means, and the cross sectional area is obtained by integration processing.

  When measuring the application cross-sectional area of the viscous liquid using an optical displacement meter as described in Patent Document 1, by obtaining the distribution of the displacement (surface height) obtained from the optical displacement meter, Similarly, the application cross-sectional area of the sealing agent can be obtained. That is, if the sealing agent 31 is applied linearly on the glass substrate 30 as shown in FIG. 2, the optical axis is set in a direction (width direction) D2 substantially perpendicular to the application direction D1 of the sealing agent 31. What is necessary is just to obtain | require distribution of displacement (surface height), moving. The means for moving the optical axis in the direction D2 is not shown in FIG. 1, but the measurement object 16 (the glass substrate 30 and the sealing agent 31) is moved with respect to the optical axis using, for example, a known XY table. You can do it. Alternatively, a mechanism for moving the objective lens 15 in the horizontal direction while fixing the mounting table of the measurement object 16 may be provided. By moving the objective lens 15 in the horizontal direction, the optical axis can be moved at high speed in a direction (width direction) across the sealing agent 31 applied in a straight line.

An example of the graph of the height distribution thus obtained is shown in FIG. In FIG. 3, a black thick line graph 33 indicates the height distribution, and a gray graph 34 superimposed on the graph 33 is a distribution (reference) of the received light amount. If such a height distribution graph 33 can be obtained, it is easy to obtain the area of the raised portion, that is, the coating cross-sectional area by integration calculation. For example, if the width W (about 360 μm in the illustrated example) of the swelled part is divided for each sampling (unit width ΔW), and the product of the displacement (height) data at each sampling point and ΔW is added, the coating cross-sectional area is can get.
Patent No. 3300803 JP 2003-28616 A

  However, in practice, a relatively clean graph 33 of the height distribution as shown in FIG. 3 is not always obtained. That is, as shown in FIG. 4, the measured value fluctuates greatly (inaccurate) on the slope of the rising portion of the height distribution graph 35, that is, the rising portion 35 a and the falling portion 35 b, and the graph is disturbed. I found it easy to happen. This phenomenon is more prominent as the liquid (sealant) clay is higher and the slope of the bulge is larger. As can be seen from the graph 36 showing the distribution of the amount of received light, the amount of light reflected on the slope of the rising portion and reaching the photodiode 18 decreases, and the amount of received light at these portions 36a and 36b becomes insufficient. This is considered to be a cause.

  As described above, when the variation of the displacement data on the slope of the swelled portion of the height distribution graph 35 is severe, the application interruption is performed by the above-described integration (addition of the product of displacement data and ΔW at each sampling point). When the area is obtained, the error becomes very large, causing a practical problem.

  In the present invention, in view of the above-described problems, when measuring the application cross-sectional area of a viscous liquid such as a sealant with an optical displacement meter, even when displacement data cannot be obtained accurately near the slope of the swelled portion. An object of the present invention is to make it possible to measure a relatively accurate coating cross-sectional area.

  A first configuration of an optical displacement meter according to the present invention projects light focused by an objective lens onto a measurement object, receives reflected light from the measurement object through the objective lens and a pinhole, and the objective lens In the optical displacement meter that detects the position of the object to be measured from the position information of the objective lens when the amount of received light is maximized. A displacement data storage unit for storing displacement data of the surface of the measurement object acquired while moving the optical axis of the measurement object relative to the measurement object by a predetermined amount, and a maximum value of a raised portion defined by the displacement data A height / width calculation unit for calculating the height and width corresponding to the cross section, and a cross section for calculating the cross-sectional area of the raised part from the height and width of the raised part obtained by the height / width calculating unit A calculation unit and a display unit for displaying a cross-sectional contour of a surface of a measurement object including a raised portion defined by the displacement data and a cross-sectional area calculated by the cross-sectional area calculation unit are provided. .

  The second configuration of the optical displacement meter according to the present invention is obtained by moving the optical axis of the objective lens and the measurement object relative to each other by a predetermined amount in the same optical displacement meter as the first configuration. A displacement data storage unit that stores displacement data of the surface of the measured object, a received light amount data storage unit that similarly stores received light amount data, and a height corresponding to the maximum value of the raised portion defined by the displacement data. A height / width calculator that calculates the width of the raised portion from the received light amount data in the raised portion, and the height and width of the raised portion determined by the height / width calculator. Calculated by the cross-sectional area calculation unit for calculating the cross-sectional area, the cross-sectional contour of the surface of the measurement object including the raised portion defined by the displacement data, and the cross-sectional area calculation unit Optical displacement meter, characterized in that it comprises a display unit for displaying the cross-sectional area that is.

  According to a third configuration of the optical displacement meter of the present invention, in the first or second configuration, the cross-sectional area calculation unit has a predetermined height and width of a raised portion determined by the height / width calculation unit, and a predetermined value. A value obtained by adding a predetermined offset to the product obtained by multiplying by a coefficient is calculated as the cross-sectional area, and a coefficient / offset setting unit for setting the coefficient and the offset to the cross-sectional area calculation unit; Furthermore, it is characterized by providing.

  According to a fourth configuration of the optical displacement meter of the present invention, in the third configuration, the coefficient / offset setting unit is different from the height and width of the raised portion obtained by the height / width calculation unit. The coefficient and the offset are calculated and set from two sets of sets of the cross-sectional area of the raised portion measured and inputted by the means.

  The first configuration of the method for measuring the application cross-sectional area of the viscous liquid according to the present invention projects the light focused by the objective lens onto the measurement object, and reflects the reflected light from the measurement object as the objective lens and the pinhole. An optical system that detects the position of the object to be measured from the position information of the objective lens when the amount of received light is maximized by detecting the position by vibrating the objective lens in the optical axis direction. A method of measuring the application cross-sectional area of a viscous liquid applied linearly on a substrate using a displacement meter, wherein (a) the optical axis of the objective lens is set in a direction perpendicular to the application direction of the viscous liquid. Acquiring and storing displacement data of the surface of the raised portion to which the viscous liquid has been applied while being relatively moved; and (b) a height corresponding to the maximum value of the raised portion defined by the displacement data. Calculating a width, and executes the step of calculating the cross-sectional area of said raised portion from the height and width of the (c) said raised portion.

  A second configuration of the method for measuring the application cross-sectional area of the viscous liquid according to the present invention is the same as the first configuration, in which (a) the optical axis of the objective lens is set in a direction perpendicular to the application direction of the viscous liquid. Acquiring and storing displacement data and received light amount data of the surface of the raised portion to which the viscous liquid has been applied while relatively moving, and (b) corresponding to the maximum value of the raised portion defined by the displacement data And calculating a width of the raised portion from the received light amount data in the raised portion, and (c) a sectional area of the raised portion from the height and width corresponding to the maximum value of the raised portion. The step of calculating is performed.

  The third configuration of the method for measuring the application cross-sectional area of the viscous liquid according to the present invention is obtained by multiplying the height and width of the raised portion by a predetermined coefficient in the step (c) of the first or second configuration. A value obtained by adding a predetermined offset to the obtained product is calculated as the cross-sectional area.

  The fourth configuration of the method for measuring the application cross-sectional area of the viscous liquid according to the present invention is measured and input by another means with the height and width of the raised portion obtained in step (b) of the third configuration. In addition, the step of calculating and setting the coefficient and the offset from two sets with the true value of the cross-sectional area of the raised portion is executed before the step (c).

  The fifth and sixth configurations of the method for measuring the application cross-sectional area of the viscous liquid according to the present invention include the objective lens in the step (a) of the first and second configurations, respectively, with respect to the application direction of the viscous liquid. The direction in which the optical axis is relatively moved is not a right angle direction but an oblique direction.

  According to a seventh configuration of the method for measuring the cross-sectional area of the viscous liquid according to the present invention, in the fifth and sixth configurations, the optical displacement meter has a light spot focused by the objective lens substantially perpendicular to the optical axis. Using a device having an optical axis scanning mechanism that scans in a straight line direction, the application cross-sectional areas of a plurality of linearly applied viscous liquids extending in different directions are measured at a plurality of locations that represent the plurality of straight lines. In this case, the objective in a direction oblique to each straight line using the optical axis scanning mechanism at the plurality of locations without causing relative rotation between the head portion of the optical displacement meter including the objective lens and the measurement object. The steps (a) to (c) are repeated a plurality of times by relatively moving the optical axis of the lens.

  According to the first configuration of the optical displacement meter of the present invention and the method for measuring the application cross-sectional area of a viscous liquid using the same, when measuring the application cross-sectional area of a viscous liquid such as a sealant with the optical displacement meter, In addition, even when displacement data cannot be accurately obtained near the slope of the bulging portion, the coating cross-sectional area can be obtained almost accurately based on the height and width of the bulging portion that can obtain relatively high measurement accuracy. That is, when a viscous liquid such as a sealant is applied to a substrate in a straight line, the cross section of the raised portion is generally shaped like a parabola with a high central part. Therefore, without using inaccurate displacement (height) data of the slope part, if the application cross-sectional area is obtained from the displacement (height) data of the central part (peak) and the width of the raised part, it is almost An accurate application cross-sectional area can be stably obtained.

  According to the second configuration of the optical displacement meter of the present invention and the method for measuring the application cross-sectional area of the viscous liquid using the same, in the first configuration, the width of the raised portion can be accurately obtained from the displacement data. Even in a difficult case, the width can be obtained almost accurately from the received light amount data. Since the amount of light received changes abruptly at the boundary between the part where the substrate surface is exposed and the part where the viscous liquid is applied, it is easy to detect the boundary on both sides from the amount of light received and determine the width between them. is there. As a result, the coating cross-sectional area can be obtained almost accurately based on the height and width of the raised portion.

  Further, according to the third configuration of the optical displacement meter of the present invention and the method for measuring the application cross-sectional area of the viscous liquid using the same, the product obtained by multiplying the height, the width, and the predetermined coefficient is a predetermined value. Since the value obtained by adding the offset is calculated as the cross-sectional area, the coating cross-sectional area can be obtained at high speed. As another method for obtaining the coating cross-sectional area based on the height and width of the raised portion, for example, a parabola (secondary curve) passing through the apex and the boundary point on both sides is obtained and surrounded by the parabola and a straight line corresponding to the substrate surface. It is also possible to obtain the area of the formed portion by the method described in the description of the prior art. However, in this case, an operation (integration operation) for obtaining and adding the area (ΔW × height) of the rectangle divided for each unit width ΔW is required, which increases the processing time. In a microprocessor having a low processing capability, such a processing burden cannot be ignored and processing takes time. On the other hand, in the third configuration of the present invention, the coating cross-sectional area can be obtained by a simple process such as adding a predetermined offset to the product obtained by multiplying the height, width, and a predetermined coefficient. Processing is completed in a short time.

  Further, according to the fourth configuration of the optical displacement meter of the present invention and the method for measuring the application cross-sectional area of the viscous liquid using the same, the true value of the cross-sectional area of the swelled portion measured by another means, respectively, Coefficients and offsets can be calculated and set from a total of two sets of data of the height and width of the raised portion correspondingly obtained. As another means, for example, when the viscous liquid is a sealant for a liquid crystal panel, when the sealant applied between two glass substrates is crushed to the thickness defined by the spacer, the sealant The cross-sectional area can be easily obtained as the product of the width of and the distance between the two glass substrates. Or before superimposing two glass substrates, you may measure the cross-sectional area of the swelling part of the sealing compound apply | coated on one glass substrate using another measuring device.

  Further, according to the fifth and sixth configurations of the method for measuring the application cross-sectional area of the viscous liquid according to the present invention, for example, the viscous liquid is applied along a rectangular frame, and is represented at two locations that respectively represent two adjacent sides. The operation | work which measures a coating cross-sectional area can be performed efficiently. In other words, it is only necessary to relatively move the optical axis in a direction that crosses two sides extending in a direction perpendicular to each other in a straight line and obliquely (for example, both at 45 degrees). Compared with the case of moving, efficient measurement is possible, and the time required for the entire measurement can be shortened.

  In this case, it is clear that if the width when crossing obliquely (angle θ) is multiplied by cos θ, it can be converted to the width when crossing at right angles. However, when the coating cross-sectional area to be finally obtained is obtained by multiplying the width and height by a predetermined coefficient as described above, the above-mentioned cos θ can be included in the coefficient. Therefore, the cross-sectional area of application can be obtained by the same calculation procedure as when crossing diagonally.

  In the seventh configuration of the viscous liquid application cross-sectional area measuring method according to the present invention, an optical displacement meter having an optical axis scanning mechanism that scans a light spot focused by the objective lens in a linear direction substantially perpendicular to the optical axis. When measuring the application cross-sectional area of a plurality of linearly applied viscous liquids extending in different directions using a plurality of locations representing a plurality of straight lines, as in the fifth or sixth configuration described above In addition, the processing for obtaining the coating cross-sectional area as described above by relatively moving the optical axis of the objective lens in an oblique direction with respect to each straight line is repeated at a plurality of locations. In this case, since there is no operation of rotating the head part of the optical displacement meter and the measurement object relative to each other, no rotation mechanism is required. Further, it is not necessary to set a plurality of head portions at a plurality of locations where the application cross-sectional area should be obtained, and efficient measurement can be performed with one head portion.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 5 is a block diagram illustrating a configuration of the optical displacement meter according to the first embodiment of the present invention. The optical displacement meter includes a displacement measuring unit 10, a displacement data storage unit 41, a height / width calculation unit 42, a cross-sectional area calculation unit 43, a display unit 44, and a coefficient / offset setting unit 45.

  The displacement measuring unit 10 has the same configuration as the conventional optical displacement meter described with reference to FIG. 1, and the reference numbers of the respective components of the displacement measuring unit 10 are the same as those in FIG. 1. The outline of the operation will be described below while avoiding the redundant description of the detailed operation of each component described in the description of the conventional example as much as possible.

  The laser light emitted from the laser diode 12 driven by the laser power control circuit 11 passes through the beam splitter 13 and the collimator lens 14, is then focused by the objective lens 15, and is projected onto the measurement object 16. The reflected light from the measurement object 16 passes through the objective lens 15 and the collimator lens 14, is reflected by the beam splitter 13 (the optical path is bent), and is received by the photodiode 18 through the pinhole 17 a of the optical diaphragm 17. . An electric signal corresponding to the amount of light received by the photodiode 18 is amplified by the amplifier 19 and then input to the arithmetic unit 20.

  The objective lens 15 is vibrated in the optical axis direction at a constant frequency and amplitude (for example, 800 Hz, ± 0.3 mm) by a solenoid 24 excited by a tuning fork amplitude control circuit 25. The vibration position is detected by the tuning fork amplitude detector 22. That is, the sine wave signal output from the tuning fork amplitude detector 22 is input to the arithmetic unit 20 through the amplifier 23. The computing unit 20 obtains position information of the objective lens 15 from the sine wave signal from the tuning fork amplitude detector 22 when the amount of light received by the photodiode 18 is maximized. Then, the position information is converted into a distance by the distance converter 26, whereby the displacement of the surface of the measurement object 16 is obtained.

  More specifically, the zero cross where the sine wave and the amplitude reference point are crossed by the calculation unit 20 based on the amplitude reference point set in the calculation unit 20 and the sine wave signal output from the tuning fork amplitude detector 22. Find a spot. Thus, the phase of the sine wave is detected, and the displacement from the zero cross point is measured from the sine wave signal from the tuning fork amplitude detector 22 when the amount of light received by the photodiode 18 is maximized, that is, in focus. ing.

  As shown in FIG. 2, the operation for measuring the application cross-sectional area of the sealing agent (viscous liquid) 31 applied linearly on the glass substrate 30 will be described along the flowchart of FIG. FIG. 6 is a flowchart showing an outline of a process for measuring the application cross-sectional area of the viscous liquid using the optical displacement meter of the first embodiment.

  In step # 11, displacement data of the surface of the measurement object 16 is acquired while relatively moving the optical axis of the objective lens 15 and the measurement object 16 by a predetermined amount (while scanning). That is, in FIG. 2, displacement data Y [i] is acquired while moving the optical axis in a direction (width direction) D2 substantially perpendicular to the application direction D1 of the sealant 31. The obtained displacement data Y [i] is stored in the displacement data storage unit 41. At this time, the width direction position X [i] is also acquired and stored. As a means for moving the optical axis of the objective lens 15 and the measurement object 16 relatively by a predetermined amount, the table on which the measurement object 16 is placed may be moved at a predetermined pitch, or conversely optical displacement. The head portion of the meter may be moved at a predetermined pitch.

  In the next step # 12, a process of calculating the height H corresponding to the maximum value of the bulging portion by the sealant and the width W of the bulging portion from the width direction position X [i] and the displacement data Y [i]. The width calculation unit 42 executes. Details of this calculation process will be described later.

  In the next step # 13, the cross-sectional area calculation unit 43 executes a process of calculating a cross-sectional area (application cross-sectional area of the sealant 31) from the height H and the width W. As a first method for calculating the cross-sectional area, as shown in FIG. 7, a parabola 48 defined by a height H and a width W is obtained, and a part surrounded by the parabola 48 and a straight line 49 corresponding to the substrate surface. Is obtained. That is, the area (ΔW × height) of each rectangle 48a divided for each unit width ΔW is obtained, and the cross-sectional area S is obtained by an operation (integration operation) of adding them.

  As a second method, the cross-sectional area S is obtained by multiplying the product of the height H and the width W by a predetermined coefficient K and adding an offset (including zero) C. That is, the cross-sectional area S is obtained by the calculation of S = H × W × K + C. If the offset C = 0, the coefficient K = 1 means that the cross-sectional shape is a rectangle, and the coefficient K = 0.5 means that the cross-sectional shape is a rectangle. Therefore, in the case of an actual application cross-sectional shape, 0.5 <K <1.

  The coefficient K and the offset C are set by the coefficient / offset setting unit 45. The coefficient / offset setting unit 45 obtains the coefficient K and the offset C from the true values of the two sets of height H, width W, and cross-sectional area S. That is, K = (S1−S2) / (H1 × W1−H2 × W2) is obtained from two sets of formulas S1 = H1 × W1 × K + C and S2 = H2 × W2 × K + C, and C = S1− H1 × W1 × K is obtained.

  At this time, the true value of the cross-sectional area S needs to be measured by another means and input to the coefficient / offset setting unit 45. In the case of a sealant for a liquid crystal panel, when the sealant applied between two glass substrates is crushed to the thickness specified by the spacer, the width of the sealant and the distance between the two glass substrates Since the cross-sectional area can be easily obtained as the product of, this can be input as the true value of the cross-sectional area. However, the present invention is not limited to this method, and the true value of the cross-sectional area measured using another measuring device may be input. Alternatively, the values of the coefficient K and the offset C may be directly input and set.

  As described above, in the optical displacement meter of the present embodiment, there are two methods for calculating the cross-sectional area, and the user can select either the first method or the second method. It has become. The cross-sectional area calculation unit 43 may be configured to use only one of the methods.

  Returning to the flowchart of FIG. 6, in the last step # 14, display by the display unit 44 or external output is executed. FIG. 8 schematically shows a display example by the display unit 44. The cross-sectional area of the swelled portion (sealing agent application cross-sectional area) obtained as described above is displayed in the display frame 51 at the upper left of the screen, and a graph of the displacement data (height) of the cross-section to be measured is displayed on the screen. It is displayed in the display frame 52 at the center. In the display frame 52, a graph of the amount of received light (light quantity) is also displayed. In this figure, the graph of height and light quantity is simplified, but in reality, the graph is as shown in FIG. 3 or FIG. The external output can output the display content of the graph of the cross-sectional area, height, and light quantity as an analog signal. Alternatively, it can be output as a digital signal to a personal computer connected via a serial interface or the like.

  Next, processing for obtaining the height and width executed by the height / width calculation unit 42 will be described with reference to FIGS. 9 to 11. 9 and 10 are flowcharts of processing for obtaining the height and width used for calculating the cross-sectional area in the optical displacement meter of the first embodiment. FIG. 11 is a diagram showing the principle of processing for obtaining the width of the rising portion from the displacement data.

  Steps # 101 to # 109 in the flowchart of FIG. 9 are processes for obtaining the height H. Subsequent to the initialization processing of the variables i and Ymax in step # 101, displacement data Y [0] at the scan start point in the width direction is acquired and stored as the substrate height in step # 102. In addition, the displacement data of only one point is not set as the substrate height, but the average value of the displacement data Y [i] (i = 0, 1, 2,...) At a plurality of points other than the raised portion is obtained to obtain the substrate height. It is good.

  In step # 103, the variable i is incremented, and after moving by ΔX in the width direction in step # 104, displacement data Y [i] is acquired in step # 105. In the next step # 106, the displacement data Y [i] is compared with the variable Ymax. If Y [i] is larger than Ymax, Y [i] is substituted for Ymax in the subsequent step # 107. If Y [i] is less than or equal to Ymax, the process proceeds to step # 108.

  In step # 108, it is checked whether i is smaller than a predetermined maximum value N (whether the scan end point has not been reached). If smaller, the process returns to step # 103. Until i reaches N (until the scan end point is reached), the processing from step # 103 to step # 108 is repeated, and when it reaches N, the maximum value of Y [i] is stored in the variable Ymax. become. In the next step # 109, the height H is obtained by subtracting the substrate height Y [0] from the maximum value Ymax.

  Steps # 111 to # 123 in the flowchart of FIG. 10 are processes for obtaining the width W. Among these, steps # 111 to # 116 are processes for detecting the left end of the swelled portion. In step # 111, the variable i is initialized to the minimum value 0, and a threshold value Yth for determining the left end of the rising portion is set. That is, the threshold value Yth is a value obtained by adding the threshold difference ΔYth to the substrate height Y [0] on the left side of the rising portion. In the next step # 112, the variable i is incremented, and after moving by ΔX in the width direction in step # 113, displacement data Y [i] is acquired in step # 114.

  In the next step # 115, Y [i] is compared with the threshold value Yth. If Y [i] is equal to or less than Yth, the process returns to step # 112. Steps # 112 to # 115 are repeated until Y [i] becomes larger than Yth, and when Y [i] becomes larger than Yth, the width direction position X [i] at that time is the left end position Xleft. (Step # 116).

  Steps # 117 to # 122 are processes for detecting the right end of the rising portion. In step # 117, the variable i is initialized to the maximum value N, and a threshold value Yth for determining the right end of the rising portion is set. That is, a value obtained by adding the threshold difference ΔYth to the substrate height Y [N] on the right side of the rising portion is set as the threshold Yth. In the next step # 118, the variable i is decremented. In step # 119, the variable i is moved by −ΔX, and then displacement data Y [i] is acquired in step # 120.

  In the next step # 121, Y [i] is compared with the threshold value Yth. If Y [i] is equal to or less than Yth, the process returns to step # 118. Steps # 118 to # 121 are repeated until Y [i] becomes larger than Yth. When Y [i] becomes larger than Yth, the width direction position X [i] at that time is the right end position Xright. (Step # 122).

  In the last step # 123, the difference between the right end position Xright and the left end position Xleft obtained as described above is obtained, and this is set as the width W.

  In the optical displacement meter of Example 1 described above, the height and width of the raised portion are calculated from the displacement data, and the cross-sectional area is calculated. However, depending on the displacement data, it may be difficult to detect the left end and the right end of the raised portion by comparison with the threshold value as described above. Therefore, in the optical displacement meter of Example 2, the width of the raised portion is calculated using the received light amount data. Since the amount of light received changes abruptly at the boundary between the part where the substrate surface is exposed and the part where the sealant is applied, it is easier to detect the left and right edges of the swelled part using the light intensity data than the displacement data. There are many cases.

  The configuration of the optical displacement meter shown in FIG. 5 is substantially the same in this embodiment. However, the displacement data storage unit 41 stores not only displacement data (and width direction position data) but also light amount data. That is, it also serves as a light quantity data storage unit. Further, the height / width calculation unit 42 calculates the width W of the swelled portion by the sealant based on the light amount data.

  FIG. 12 is a flowchart showing an outline of a process for measuring the application cross-sectional area of the viscous liquid using the optical displacement meter of the second embodiment. Only the difference from the optical displacement meter of the first embodiment shown in FIG. 6 will be described. In step # 21, the received light amount data in addition to the width direction position data X [i] and the displacement data Y [i]. L [i] is also acquired and stored. In the next step # 22, the height H corresponding to the maximum value of the bulging portion due to the sealant is calculated from the displacement data Y [i], and in the subsequent step # 23, the width direction position X [i] and the received light amount data L [i]. ], The width W of the raised portion due to the sealant is calculated. Steps # 24 and # 25 are the same as steps # 13 and # 14 in FIG.

  Next, a process for calculating the width of the rising portion from the received light amount data executed by the height / width calculation unit 42 will be described with reference to FIGS. 13 and 14. FIG. 13 is a flowchart of processing for obtaining the width of the raised portion in the optical displacement meter of the second embodiment. FIG. 14 is a diagram illustrating the principle of processing for obtaining the width of the rising portion from the received light amount data. The flowchart in FIG. 13 corresponds to the flowchart in FIG. 10 in the first embodiment. The processing for obtaining the height of the raised portion is the same as the processing described with reference to FIG.

  In the flowchart of FIG. 13, steps # 211 to # 216 are processing for detecting the left end of the swelled portion. The variable i in step # 211 is initialized to the minimum value 0, and a threshold value Lth for determining the left end of the rising portion is set. That is, a value obtained by subtracting the threshold difference ΔLth from the received light amount L [0] on the substrate surface on the left side of the rising portion is set as the received light amount threshold value Lth. In the next step # 212, the variable i is incremented, and after moving by ΔX in the width direction in step # 213, the received light amount data L [i] is acquired in step # 214.

  In the next step # 215, L [i] is compared with the threshold value Lth. If L [i] is equal to or greater than Lth, the process returns to step # 212. Steps # 212 to # 215 are repeated until L [i] becomes smaller than Lth. When L [i] becomes smaller than Lth, the width direction position X [i] at that time is the left end position Xleft. (Step # 216).

  Steps # 217 to # 222 are processes for detecting the right end of the rising portion. In step # 217, the variable i is initialized to the maximum value N, and a threshold value Lth for determining the right end of the rising portion is set. That is, a value obtained by subtracting the threshold difference ΔLth from the amount of light received L [N] on the substrate surface on the right side of the rising portion is set as the threshold value Lth. In the next step # 218, the variable i is decremented. In step # 219, the variable i is moved by −ΔX, and then the received light amount data L [i] is acquired in step # 220.

  In the next step # 221, L [i] is compared with the threshold value Lth. If L [i] is equal to or greater than Lth, the process returns to step # 218. Steps # 218 to # 221 are repeated until L [i] becomes smaller than Lth. When L [i] becomes smaller than Lth, the width direction position X [i] at that time is the right end position Xright. (Step # 222).

  In the last step # 223, the difference between the right end position Xright and the left end position Xleft obtained as described above is obtained, and this is set as the width W.

  FIG. 15 is a block diagram illustrating a configuration of an optical displacement meter according to the third embodiment of the present invention. However, only the displacement measuring unit 10 in the configuration of the optical displacement meter of the first embodiment shown in FIG. 5 is shown, and the same applies to the configuration block for calculating the already-described section of the viscous liquid from the height and width. Therefore, illustration is abbreviate | omitted.

  The optical displacement meter of the present embodiment has an optical axis scanning mechanism 28 that scans a light spot focused by the objective lens 15 in a linear direction substantially perpendicular to the optical axis. The means for moving the light spot focused by the objective lens 15 on the surface of the measurement object, that is, the means for moving the optical axis of the objective lens 15 and the measurement object 16 relative to each other is as described above. A means for moving the table to be placed may be used, or a means for moving the head portion of the optical displacement meter may be used. The optical axis scanning mechanism 28 of the optical displacement meter of this embodiment does not move the entire head portion of the optical displacement meter, but only the objective lens 15 and its peripheral portion in a linear direction substantially perpendicular to the optical axis. By vibrating, the light spot is scanned in a linear direction substantially perpendicular to the optical axis.

  In FIG. 15, a block surrounded by a broken line constitutes an objective lens unit 27 including the objective lens 15, tuning fork 21, solenoid 24, and amplitude detector 22. The objective lens unit 27 is configured to be swingable within a narrow angle around a support shaft 27X parallel to the optical axis of the objective lens 15. As means for swinging the objective lens unit 27 at a predetermined cycle, a magnet is provided on the objective lens unit 27 side, and an electromagnetic coil is provided on the fixed frame side. In FIG. 15, an optical axis scanning mechanism 28 including an electromagnetic coil and its drive control circuit is shown. Further, a scanning position detector 29 for detecting the swing position of the objective lens unit 27, that is, the scanning position of the optical axis, is provided, and the output signal is fed back to the optical axis scanning mechanism 28. The optical axis scanning mechanism 28 controls the swing of the objective lens unit 27, that is, scanning of the optical axis, based on the scanning position control signal given from the calculation unit 20 and the scanning position signal fed back from the scanning position detector 29. To do.

  FIG. 16 is a diagram illustrating a first measurement method using the optical displacement meter of the present embodiment. This example shows a state in which a sealing agent 62, which is a viscous liquid, is applied along the four sides of the glass substrate 61 constituting the liquid crystal display and its application cross-sectional area is measured in the manufacturing process of the liquid crystal display. An optical axis locus surface 64 shows a state in which the laser beam irradiated from the tip of the head portion 63 of the optical displacement meter toward the sealant 62 is scanned by the optical axis scanning mechanism 28 described above. In this measurement method, the application cross-sectional area is measured for two sides 65 and 66 of a substantially rectangular shape to which the sealing agent 62 is applied. In this case, two head units 63 of the optical displacement meter are used, and each head unit 63 is set at an appropriate location on each side.

  The scanning direction (optical axis locus surface 64) of the laser light emitted from each head portion 63 is a direction perpendicular to the side (coating direction). Therefore, the scanning direction of the laser beam (optical axis locus surface 64) on the side 65 is different from the scanning direction of the laser beam (optical axis locus surface 64) on the side 66 by 90 degrees. If it is attempted to measure the coating cross-sectional areas at the two locations with one head unit 63 without setting two head units 63 of the optical displacement meter, for example, the measurement at the side 65 is finished and then the side 66 is When starting the measurement, it is necessary to rotate the head portion 63 by 90 degrees. Alternatively, it is necessary to rotate the table on which the glass substrate 61 is placed by 90 degrees. In any case, when the rotation mechanism is not prepared, the two application cross-sectional areas cannot be measured with one head unit 63.

  FIG. 17 is a diagram showing a second measurement method using the optical displacement meter of this example. Unlike the first measurement method, this measurement method uses only one head portion 63 of the optical displacement meter, and without rotating the table on which the head portion 63 or the glass substrate 61 is placed, the application direction Measure the cross-sectional area of coating on two different sides. As shown in FIG. 17, the head portion 63 of the optical displacement meter is set so that the scanning direction of the laser light (optical axis locus surface 64) is oblique (for example, both 45 degrees) with respect to the two adjacent sides 65 and 66. And the glass substrate 61 are set. That is, the optical axis is not moved at right angles to the application direction (side) of the sealant 62 for measuring the cross-sectional area, but is moved obliquely (for example, in the direction of 45 degrees).

  In this case, a measurement result equivalent to the first measurement method of moving the optical axis at a right angle should be obtained for the height of the coating cross section, but the measurement of the first measurement method is performed because the width crosses diagonally. Longer than the result. When the scanning direction of the laser beam makes an angle θ with respect to the coating direction (side), the obtained width can be converted to the measurement result (true width) by multiplying the obtained width by cos θ. For example, when the angle is 45 degrees, the calculation may be performed by dividing by the square root of 2 (about 1.414). However, in actuality, as described above, the height and width, which are measurement results, are multiplied by a coefficient K (adding an offset C if necessary) to obtain a cross-sectional area, and the above-described cos θ The number of operations can be reduced by including.

  According to this measuring method, for example, when the measurement at the side 65 is finished and then the measurement at the side 66 is started, the head portion 63 (or the table on which the glass substrate 61 is placed) is indicated by a broken-line arrow. It is only necessary to translate them, and there is no need to rotate them relatively. It should be noted that it is not always necessary for the two sides 65 and 66 extending in the direction perpendicular to each other so that the scanning direction of the laser light is 45 degrees with respect to the sides. For example, the angle may be 30 degrees with respect to one side and 60 degrees with respect to the other side. When the scanning direction of the laser beam is an angle θ other than 45 degrees with respect to the coating direction (side), as described above, cos θ or a coefficient K including the same is used as the position information (head unit 63 and measurement object ( It is necessary to obtain it from information representing a relative position with respect to the glass substrate 61). For example, cos θ or a coefficient K including the same may be obtained from the position information by referring to a previously stored table. As a hardware configuration, means for inputting and storing data constituting such a table, driving means for changing the relative position between the head portion 63 and the measurement object (glass substrate 61), position information which is the current relative position And a means for obtaining cos θ corresponding to the position information or a coefficient K including the same by referring to the table. In addition, as a precondition for the measurement method in which the optical axis is moved obliquely with respect to the application direction (side) of the sealant 62, the width of the application cross section does not vary greatly at least within a range that obliquely crosses the application direction. (Variation in width should be negligible).

  As mentioned above, although the Example of this invention was described referring the modification suitably, this invention may be implemented with the form which further modified these Example and the modification. In the above embodiment, the objective lens is vibrated in the optical axis direction by the vibration of the tuning fork, but the objective lens may be vibrated in the optical axis direction using other known means such as a piezoelectric element.

It is a block diagram which shows the structure of the conventional optical displacement meter. It is a figure which shows an example of the measurement by an optical displacement meter. It is a graph which shows the example of the measurement result of FIG. It is a graph which shows another example of the measurement result of FIG. It is a block diagram which shows the structure of the optical displacement meter which concerns on Example 1 of this invention. 3 is a flowchart showing an outline of a process for measuring the application cross-sectional area of a viscous liquid using the optical displacement meter of Example 1. It is a figure which shows the 1st method of cross-sectional area calculation. It is a figure which shows the example of a display by a display part typically. 3 is a flowchart of the first half of a process for obtaining a height and a width used for calculating a cross-sectional area in the optical displacement meter of Example 1. FIG. 6 is a flowchart of the latter half of the process for obtaining the height and width used for calculating the cross-sectional area in the optical displacement meter of Example 1. FIG. It is a figure which shows the principle of the process which calculates | requires the width | variety of a rising part from displacement data. 6 is a flowchart showing an outline of a process for measuring the application cross-sectional area of a viscous liquid using the optical displacement meter of Example 2. 10 is a flowchart of processing for obtaining a width of a raised portion in the optical displacement meter of Example 2. It is a figure which shows the principle of the process which calculates | requires the width | variety of a rising part from received light amount data. It is a block diagram which shows the structure of the optical displacement meter which concerns on Example 3 of this invention. 6 is a diagram illustrating a first measurement method using the optical displacement meter of Example 3. FIG. 6 is a diagram illustrating a second measurement method using the optical displacement meter of Example 3. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 15 Objective lens 16 Measurement object 17a Pinhole 41 Displacement data storage part (also received light amount data storage part)
42 Height / Width Calculation Unit 43 Cross Section Area Calculation Unit 44 Display Unit 45 Coefficient / Offset Setting Unit

Claims (11)

The light focused by the objective lens is projected onto the measurement object, the reflected light from the measurement object is received through the objective lens and the pinhole, and the position is detected by vibrating the objective lens in the optical axis direction. An optical displacement meter that measures the displacement of the surface of the measurement object from the position information of the objective lens when the amount of received light is maximized,
A displacement data storage unit for storing displacement data of the surface of the measurement object acquired while relatively moving the optical axis of the objective lens and the measurement object by a predetermined amount;
A height / width calculator for calculating a height and a width corresponding to the maximum value of the raised portion defined by the displacement data;
A cross-sectional area calculating unit that calculates a cross-sectional area of the raised part from the height and width of the raised part obtained by the height / width calculating part;
An optical displacement meter, comprising: a display section that displays a cross-sectional contour of a surface of a measurement object including a raised portion defined by the displacement data and a cross-sectional area calculated by the cross-sectional area calculation section. . The light focused by the objective lens is projected onto the measurement object, the reflected light from the measurement object is received through the objective lens and the pinhole, and the position is detected by vibrating the objective lens in the optical axis direction. An optical displacement meter that measures the displacement of the surface of the measurement object from the position information of the objective lens when the amount of received light is maximized,
A displacement data storage unit that stores displacement data of the surface of the measurement object acquired while moving the optical axis of the objective lens and the measurement object relatively by a predetermined amount, and a received light amount that also stores received light amount data A data storage unit;
Calculating a height corresponding to the maximum value of the swelled portion defined by the displacement data, and a height / width calculating unit for calculating a width of the swelled portion from the received light amount data in the swelled portion;
A cross-sectional area calculating unit that calculates a cross-sectional area of the raised part from the height and width of the raised part obtained by the height / width calculating part;
An optical displacement meter, comprising: a display section that displays a cross-sectional contour of a surface of a measurement object including a raised portion defined by the displacement data and a cross-sectional area calculated by the cross-sectional area calculation section. . The cross-sectional area calculation unit adds a predetermined offset to a product obtained by multiplying the height and width of the raised portion obtained by the height / width calculation unit and a predetermined coefficient, and calculates a value obtained by adding the predetermined offset. The optical displacement meter according to claim 1, further comprising a coefficient / offset setting unit that calculates an area and sets the coefficient and the offset with respect to the cross-sectional area calculation unit. The coefficient / offset setting unit is a set 2 of the height and width of the raised portion obtained by the height / width calculating unit and the true value of the cross-sectional area of the raised portion measured and input by another means. The optical displacement meter according to claim 3, wherein the coefficient and the offset are calculated and set from a set. The light focused by the objective lens is projected onto the measurement object, the reflected light from the measurement object is received through the objective lens and the pinhole, and the position is detected by vibrating the objective lens in the optical axis direction. The application cross-section of the viscous liquid applied linearly on the substrate using an optical displacement meter that measures the displacement of the surface of the object to be measured from the position information of the objective lens when the amount of received light is maximized A method of measuring
(A) acquiring and storing displacement data of the surface of the raised portion to which the viscous liquid has been applied while relatively moving the optical axis of the objective lens in a direction perpendicular to the application direction of the viscous liquid;
(B) calculating a height and a width corresponding to a maximum value of a raised portion defined by the displacement data;
(C) The step of calculating the cross-sectional area of the raised part from the height and width of the raised part is executed. The light focused by the objective lens is projected onto the measurement object, the reflected light from the measurement object is received through the objective lens and the pinhole, and the position is detected by vibrating the objective lens in the optical axis direction. The application cross-section of the viscous liquid applied linearly on the substrate using an optical displacement meter that measures the displacement of the surface of the object to be measured from the position information of the objective lens when the amount of received light is maximized A method of measuring
(A) Acquiring and storing displacement data and received light amount data of the surface of the raised portion coated with the viscous liquid while relatively moving the optical axis of the objective lens in a direction perpendicular to the application direction of the viscous liquid. And steps to
(B) calculating a height corresponding to a maximum value of the raised portion defined by the displacement data, and calculating a width of the raised portion from the received light amount data in the raised portion;
(C) calculating the cross-sectional area of the raised portion from the height and the width corresponding to the maximum value of the raised portion. In the step (c), a value obtained by adding a predetermined offset to a product obtained by multiplying the height and width of the raised portion by a predetermined coefficient is calculated as the cross-sectional area. Item 7. The method for measuring the cross-sectional area of the viscous liquid according to item 5 or 6. The coefficient and the offset are calculated from two sets of the height and width of the raised portion obtained in step (b) and the true value of the cross-sectional area of the raised portion measured and input by another means. The method for measuring the cross-sectional area of the viscous liquid according to claim 7, wherein the setting step is performed before the step (c). 6. The viscosity according to claim 5, wherein in the step (a), the direction in which the optical axis of the objective lens is moved relative to the application direction of the viscous liquid is not a right angle direction but an oblique direction. A method for measuring the cross-sectional area of liquid applied. The viscosity according to claim 6, wherein, in the step (a), the direction in which the optical axis of the objective lens is moved relative to the application direction of the viscous liquid is not a right angle direction but an oblique direction. A method for measuring the cross-sectional area of liquid applied. The optical displacement meter uses an optical axis scanning mechanism that scans a light spot focused by the objective lens in a linear direction substantially perpendicular to the optical axis, and is applied in a plurality of linear shapes extending in different directions. When measuring the application cross-sectional area of the viscous liquid at a plurality of locations representing the plurality of straight lines, the head portion of the optical displacement meter including the objective lens and the measurement object are not rotated relative to each other at the plurality of locations. The steps (a) to (c) are repeated a plurality of times by relatively moving the optical axis of the objective lens in an oblique direction with respect to each straight line using the optical axis scanning mechanism. The measuring method of the application cross-sectional area of the viscous liquid of 9 or 10.

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