WO2018008851A1

WO2018008851A1 - Thickness measuring apparatus

Info

Publication number: WO2018008851A1
Application number: PCT/KR2017/005663
Authority: WO
Inventors: 배진형
Original assignee: 엘지전자 주식회사
Priority date: 2016-07-03
Filing date: 2017-05-31
Publication date: 2018-01-11
Also published as: KR20190020143A; KR102137160B1

Abstract

A thickness measuring apparatus according to an embodiment of the present invention may comprise: a light emission unit for irradiating light to an object; a lens unit for collecting light generated in the light emission unit; a lattice pattern generation unit through which light collected through the lens unit passes; a light reception unit for receiving light reflected from multiple interlayer boundaries of the object; and a calculation unit for obtaining a thickness of at least one of multiple layers of the object on the basis of a difference in height between lattice patterns which are formed on a surface of the object by the lattice pattern generation unit.

Description

Thickness measuring device

The present invention relates to a thickness measuring apparatus, and specifically, to an apparatus for measuring thickness and height uniformity of a resin filled between a cover glass and a panel in an optical bonding apparatus using a resin by using an optical interference fringe. It is about.

Smart electronic devices, such as smart phones and tablet PCs, which are widely used in recent years, may not only display an image but also include a touch screen that receives a touch from a user. In this case, the touch screen may be formed as a bonded structure of the display panel and the TPS module.

The conventional touch screen is provided to include an air gap between the display panel and the TPS module. However, recently, in order to improve outdoor visibility, instead of an air gap, a transparent resin (Regin) is filled and cured with ultraviolet rays to bond the display panel and the TPS module.

When the resin is used to manufacture the touch screen, since the bonding surface is non-parallel due to manufacturing tolerances of the display panel and the TPS module, the uniformity of the resin layer thickness may be lowered.

In order to form a resin layer with a uniform thickness, it is necessary to measure the thickness of the resin layer.

An object of the present invention is to provide a thickness measuring device for measuring the height of the object faster than the laser point measuring method.

Another object of the present invention is to provide a thickness measuring apparatus for easily and quickly generating a grid pattern corresponding to different objects.

According to an embodiment of the present invention, a thickness measuring apparatus includes a light emitting unit for irradiating light to an object, a lens unit collecting light generated from the light emitting unit, a lattice generating unit through which light collected through the lens unit passes, and a plurality of objects A light receiving unit for receiving light reflected from the interlayer boundary of the and the calculation unit for obtaining the thickness of at least one of the plurality of layers of the object based on the height difference of the grid pattern formed on the surface of the object according to the grid pattern generating unit It is characterized by including.

In addition, the calculating unit of the thickness measuring apparatus according to an embodiment of the present invention, by using the difference between the two adjacent distances of the plurality of light receiving position, to obtain the thickness of any one of the plurality of layers constituting the object. It is done.

In addition, the calculation unit of the thickness measuring apparatus according to an embodiment of the present invention, by using the incident angle when the light emitted from the light emitting unit is incident on the surface of the object, one of one or more layers constituting the object It characterized in that it comprises obtaining the thickness of.

In addition, the calculation unit of the thickness measuring apparatus according to an embodiment of the present invention, by using the refractive index of the one or more layers constituting the object, to obtain the thickness of any one of the one or more layers constituting the object It is done.

In addition, the thickness measuring apparatus according to an embodiment of the present invention is characterized in that it further comprises a display unit for displaying the thickness of at least one of the plurality of layers of the object obtained by the operation unit.

In addition, the display unit of the thickness measuring apparatus according to an embodiment of the present invention is characterized in that it comprises displaying the thickness obtained by the calculation unit in the contour line.

The effects of the present invention are as follows.

According to one embodiment of the various embodiments of the present disclosure, there is a technical effect of providing a thickness measuring apparatus for measuring a height of an object faster than a laser point measuring method by irradiating a grid pattern on the front surface of the object once.

According to another embodiment of the various embodiments of the present disclosure, it is possible to simply replace the grid pattern generator as a part of the device, thereby providing a thickness measuring device for easily and quickly generating a grid pattern corresponding to different objects. There is.

1 is a perspective view schematically showing an embodiment of a thickness measuring apparatus.

2 is a control block diagram according to an embodiment of a thickness measuring apparatus.

3 is a view for explaining the operation of the displacement sensor according to an embodiment of the thickness measuring apparatus.

4 and 5 are views for explaining the operation of the transfer unit according to an embodiment of the thickness measuring device.

6 is a flowchart according to an embodiment of a method for controlling a thickness measurement device.

7 to 10 are views for explaining the operating method of the thickness measurement apparatus according to a first embodiment of the present invention.

11 to 15 are diagrams for describing an operating method of the thickness measuring apparatus according to the first embodiment of the present invention.

Hereinafter, exemplary embodiments related to the present invention will be described in detail with reference to the accompanying drawings. The suffixes "module" and "unit" for components used in the following description are given or used in consideration of ease of specification, and do not have distinct meanings or roles from each other.

1 is a perspective view schematically showing an embodiment of a thickness measuring apparatus. First, the appearance of the thickness measuring apparatus will be described with reference to FIG. 1.

According to an embodiment of the thickness measuring apparatus, the displacement sensor 110, a table 120, a transfer unit 130, a computer 140, a display 150, and a support unit 160 may be included.

The table 120 may have an upper surface and a lower surface on the XY plane parallel to the ground surface. The object Ob may be placed on an upper surface of the table 120, and thickness measurement may be performed on the object Ob positioned therein.

The object Ob may be composed of a plurality of layers. In addition, each layer constituting the object Ob may be made of a material capable of transmitting light. For example, the object Ob may be a touch screen in which the touch panel and the LCD panel are bonded to the resin.

Alternatively, the object Ob may be a touch screen in which tempered glass and an OTCA (On Cell Touch AMOLED) display are bonded to a resin.

The displacement sensor 110 may be spaced apart from the upper surface of the table 120. To this end, the displacement sensor may be provided to be connected to the support 160.

The support unit 160 may extend in a Z-axis direction perpendicular to the ground surface.

The displacement sensor 110 may irradiate light onto the object Ob placed on the table 120. In addition, the displacement sensor may receive light reflected at each of the plurality of layer boundaries of the object Ob.

The received light information may be transmitted to the computer 140.

The computer 140 may acquire the thickness of at least one of the plurality of layers of the object Ob based on the received light.

The display 150 may display the thickness obtained by the computer 140 to inform the user.

The computer 140 may include a calculator 141 and a controller 142, which will be described later.

A lower surface may be provided to face the upper surface of the table 120, and the transfer unit 130 may be coupled to the lower surface of the table 120. The transfer unit 130 may move the table 120 to move the object Ob to a desired position.

In detail, the transfer part 130 may be formed in the first transfer part 131 and the first direction to move the table 120 so that the object Ob is transferred in the first direction, which is a direction in which the plurality of layers of the object Ob are stacked. In order for the object Ob to be transported in the second vertical direction, the second conveyance unit 132 for moving the table 120 and the object Ob in the third direction perpendicular to the first and second directions are transported. It may include a third transfer unit 133 for moving the table 120.

In this case, the first direction may be a Z-axis direction, the second direction may be a Y-axis direction, and the third direction may be an X-axis direction.

According to an embodiment of the thickness measuring apparatus for measuring the thickness of each layer of the object (Ob), the light emitting portion 111 for irradiating light to the object (Ob) consisting of a plurality of layers and the plurality of layers between the object (Ob) A displacement sensor 110 including a light receiving unit 112 for receiving the light reflected from the boundary; an operation unit 141 for obtaining a thickness of at least one of the plurality of layers based on the plurality of light receiving positions of the light receiving unit 112; It may include a display 150 for displaying the thickness of at least one layer and a control unit 142 for controlling the overall operation of the thickness measuring device.

The displacement sensor 110 may receive light including information about the thicknesses of the plurality of layers of the object Ob. In detail, the displacement sensor 110 may irradiate light onto the object Ob through the light emitter 111 and receive light reflected from a plurality of interlayer boundaries of the object Ob through the receiver.

In this case, the light received by the receiver may include thickness information of a plurality of layers of the object Ob.

3 is a view for explaining the operation of the displacement sensor 110 according to an embodiment of the thickness measuring apparatus.

The arrow may mean a path of light.

In addition, the object Ob will be described on the assumption that the first layer Ob1 of the refractive index n1 and the second layer Ob2 of the refractive index n2 are configured.

As shown in FIG. 3, the light emitting unit 111 of the displacement sensor 110 may irradiate light to the object Ob.

The irradiated light may have a predetermined angle of incidence when incident on the surface of the object Ob. 3, the incident angle of the irradiated light with respect to the object Ob may be θ0 μs.

A part of the light reaching the object Ob at the incident angle θ0 may be reflected and received at the first light receiving position ① of the light receiving unit 112. In this case, the first light receiving position ① may refer to a position where the light receiving unit 112 receives the most light among regions in which the light is received from the surface of the object Ob.

Unlike this, a part of the light reaching the object Ob at the incident angle θ0 may pass through the first layer Ob1 of the object Ob.

Since the refractive index of the first layer Ob1 of the object Ob is n1 μs, the traveling path of the light may be changed accordingly. As a result, light may travel through the first layer Ob1 at a refractive angle θ1.

A portion of the light traveling through the first layer Ob1 with the refraction angle θ1 may be reflected at the boundary between the first layer Ob1 and the second layer Ob2, and may be received at the second light receiving position ② of the light receiver 112. have.

In this case, the second light receiving position ② may refer to a position where the light receiving unit 112 receives the most light among regions in which light is received at the boundary between the first layer and the second layer Ob2. .

In addition, a portion of the light traveling through the first layer Ob1 with the refractive angle θ1 may pass through the second layer Ob2 of the object Ob. In this case, since the refractive index of the second layer Ob2 of the object Obb is n 2 μs, the path of the light may be changed accordingly.

As a result, the light may travel through the second layer Ob2 with the refractive angle θ2.

Meanwhile, the light traveling through the second layer Ob2 with the refractive angle θ2 may be reflected at the boundary of the second layer Ob2 and received at the third light receiving position ③ of the light receiver 112.

In this case, the third light receiving position ③ may refer to a position where the light receiving unit 112 receives the most light among regions in which the light receiving unit 112 receives the light reflected from the boundary of the second layer Ob2.

As such, the displacement sensor 110 may receive the light reflected from the plurality of interlayer boundaries at different light receiving positions. The calculator 141, which will be described later, may acquire thicknesses of the plurality of layers of the object Ob by using the difference in the light receiving positions.

Referring back to FIG. 2, the calculator 141 may receive a plurality of light receiving positions from the displacement sensor 110. The calculating unit 141 may obtain the thickness of at least one of the plurality of layers based on the received plurality of light receiving positions.

In detail, the calculator 141 may acquire thicknesses of the plurality of layers of the object Ob using Snell's Law.

When light is refracted at the boundary of two isotropic, nonconductive media with different refractive indices, Snell's law holds between the direction of the incident light and the refracted light.

In detail, FIG. 3 follows Equation 1.

[Equation 1]

sinθ ₀ = n ₁ sinθ ₁ = n ₂ sinθ ₂

Using Equation 1, the refractive angles θ1 and θ2 can be obtained. That is, by using the incident angle θ0 when the light emitted from the light emitter 111 is incident on the surface of the object Ob and the refractive index of the layer to obtain the thickness, the refractive angle of the layer may be obtained.

Using the obtained refractive angle, the thickness of the layer corresponding to the refractive angle can be obtained. In the case of FIG. 3, the thickness of the first layer Ob1 may be obtained by using the refractive angle θ1. Specifically, the thickness of the first layer Ob1 follows Equation 2.

[Equation 2]

t ₁ = a / (2tanθ ₁ )

Here, a may mean a difference between the first light receiving position and the second light receiving position.

In addition, the thickness of the second layer Ob2 may be obtained by using the refractive angle θ2. Specifically, the thickness of the second layer Ob2 follows Equation 3.

[Equation 3]

t ₂ = b / (2tanθ ₂ )

Here, b may mean a difference between the second light receiving position and the third light receiving position.

By using the distance difference between adjacent light receiving positions, the thickness of the corresponding layer can be obtained.

Referring back to FIG. 2, the display 150 may display the thickness of at least one layer obtained by the calculator 141.

4 and 5, the object Ob may be a touch screen of the smart phone.

In the case of FIG. 4, the thickness measurement for the C position of the object Ob may be performed.

After the thickness measurement for the C position is finished, the transfer unit 130 may transfer the table 120 so that light is incident on a predetermined position of the object Ob.

In the case of FIG. 5, the third transfer part 133 may move the table 120 in the X-axis direction so that light is incident at a predetermined position D. FIG.

As a result, the object Ob is transferred in the X-axis direction, and the thickness measuring apparatus may measure the thickness of the object Ob at the D position.

4 and 5 illustrate only the case where the table 120 is moved in the X-axis direction by the first transfer unit 131, but the table 120 is also moved in the Y-axis direction by the second transfer unit 132. Alternatively, the table 120 may be moved in the Z-axis direction by the third transfer unit 133.

As such, when the thickness of at least one layer at a plurality of positions of the object Ob is measured by the transfer unit 130, the display 150 measures the thickness of the at least one layer according to the change of the position of the object Ob. I can display it.

In detail, the display 150 may display the thickness of at least one layer in a contour line.

First, light may be irradiated onto the object Ob. In this case, the object Ob may be composed of a plurality of layers, and each layer may be formed of a material capable of transmitting light.

Next, light reflected from the plurality of interlayer boundaries of the object Ob may be received. At this time, the light receiving position may vary depending on the layer reflecting light.

The light receiving position may include thickness information of a layer reflecting light.

After receiving the reflected light, the distance difference of the light receiving position can be obtained. Specifically, the distance between adjacent light receiving positions can be obtained.

The thickness of at least one of the plurality of layers may be obtained based on the obtained distance between the light receiving positions. The process of obtaining the thickness of the at least one layer may be based on Equation 1, Equation 2, and Equation 3.

Finally, the thickness information of the obtained at least one layer may be displayed to provide thickness information to the user.

At this time, the received light amount according to the light receiving position may be displayed together.

If the thickness of at least one layer is measured at a plurality of positions of the object Ob, the thickness change of the at least one layer according to the position of the object Ob may be displayed.

In particular, the thickness of at least one layer can be displayed in a contour graph.

Using the contour graph, the user can easily recognize the thickness information through the contour graph.

7 to 10 are views for explaining the operation method of the thickness measurement apparatus according to an embodiment of the present invention.

As illustrated in FIG. 7, the thickness measuring apparatus according to the exemplary embodiment of the present invention may measure the thickness and height of the resin 730 using the laser 740.

As shown in FIGS. 7A to 7C, the resin 730 may be filled between the cover glass 710 and the panel 720 in optical adhesion.

After the resin 730 is filled, the cover glass 710 may be compressed by pressing the cover glass 710.

At this time, as shown in Figure 7 (d), it is possible to measure the thickness or height of the resin of a specific point using the laser 740 of the thickness measuring device.

That is, as shown in FIG. 8, the first laser reflected from the cover glass 710, the second laser reflected from the resin 730, and the panel 720 are reflected using the laser 740 of the thickness measuring apparatus. The third laser can be separated and measured.

Through such a process, the thickness measuring apparatus may measure the thickness or height of the resin 720.

In addition, as shown in FIG. 9, such a thickness measurement method may be performed for each of a plurality of points 900 in a liquid crystal such as a smartphone.

That is, as shown in Figure 10, by periodically irradiating the laser in the direction of the smartphone liquid crystal while moving the laser 740 of the thickness measuring device, it is possible to measure the thickness or height of the resin for each point of the entire area of the smartphone. have.

That is, the thickness measuring apparatus according to the first exemplary embodiment of the present invention may calculate a resin thickness of a region to be measured by separating a reflected laser for each layer by irradiating a laser to a portion to measure thickness.

In this method, only one point or one line of resin thickness can be measured in one laser irradiation.

And, when there are many measurement points, it takes a lot of measurement time.

In addition, if the reflection characteristic is changed by foreign matter or bubbles, measurement is impossible.

In addition, there may be disadvantages in that the laser focus needs to be readjusted when the height of the workpiece is changed, and a separate data analysis is required to grasp the overall tendency.

11 to 16 are diagrams for describing an operating method of the thickness measuring apparatus according to the first embodiment of the present invention.

As illustrated in FIG. 11, the thickness measuring apparatus according to the first exemplary embodiment of the present invention may include a camera 1110, a lens 1120, a grid pattern generator 1130, and an illumination 1140.

As shown in FIG. 12, a grid pattern may be generated according to the type of the grid pattern generator 1130. The grid pattern 1210 of the first type, the grid pattern 1220 of the second type, and the third type of the grid pattern generator 1130 may be generated. The grid pattern 1230 may be generated.

In addition, as shown in FIG. 13, the grid pattern 1210 of the first type may be divided into a vertical grid 1212 and a horizontal grid 1214, and the grid pattern 1230 of the third type is a solid line and a dotted line. Adjustable by

The way is simple.

As shown in FIG. 14, when light is irradiated, light passes through the pattern masks 1410 and 1420, and as a result, a lattice pattern may be formed on the bottom surface corresponding to the shape of the pattern masks 1410 and 1420. .

Thus, as shown in Figure 15, the grid pattern formed on the bottom can form a curved surface according to the surface of the resin, etc., it is possible to calculate the height difference of the resin through the height difference between the surfaces.

The thickness measuring apparatus according to the first embodiment of the present invention may selectively use a pattern, and the lattice pattern may be made by using a laser and an LED, or may be made by using a pattern mast or a pattern glass.

In the thickness measurement principle, when the height is the same, the grid pattern projected on the object has the same grid pattern, and at this time, the irradiated grid may be recognized by the camera to measure the distance between the grids. If the measured values are the same, the principle is that there is no change in height or thickness.

If the grid pattern is irradiated when there is a height change, the grid pattern may be distorted, and the height change may be detected by measuring the distorted gap.

In addition, the method of the present invention has a technical effect of quickly measuring the total area of the object to be measured by measuring the height and thickness by obtaining a single image of the area entering the camera area.

In addition, precise measurement is possible according to the resolution of the camera and the grating generating unit, and there is an advantage that the simultaneous measurement can be performed by combining several optical systems.

That is, since the concept of area measurement is higher than that of the laser point measurement method, the measurement speed is fast and the system can be inlined by obtaining the single image and quickly extracting the height information.

In addition, it is possible to detect the change in height and thickness, so that the change in material or the quality of the product can be known, and there is an advantage that the measurement can be focused by using a different plaid pattern according to the measurement characteristic and shape.

The thickness measuring apparatus described above is not limited to the configuration and method of the above-described embodiments, but the embodiments are configured by selectively combining all or some of the embodiments so that various modifications can be made. May be

Claims

In the thickness measuring device,

Light emitting unit for irradiating light to the object;

A lens unit collecting light generated from the light emitting unit;

A grid pattern generating unit through which light collected through the lens unit passes;

A light receiver configured to receive light reflected from a plurality of interlayer boundaries of the object; And

And a calculator configured to obtain a thickness of at least one of a plurality of layers of the object based on the height difference of the grid formed on the surface of the object according to the grid pattern generator.

Thickness measuring device.
According to claim 1,

The calculation unit,

Obtaining a thickness of any one of a plurality of layers constituting the object by using a distance difference between two adjacent ones of the plurality of light receiving positions;

Thickness measuring device.
According to claim 1,

The calculation unit,

Obtaining a thickness of any one or more layers of one or more layers constituting the object by using an incident angle when the light emitted from the light emitter is incident on the surface of the object.

Thickness measuring device.
According to claim 1,

The calculation unit,

Obtaining the thickness of one of the one or more layers constituting the object by using the refractive indices of the one or more layers constituting the object,

Thickness measuring device.
According to claim 1,

Further comprising a display unit for displaying the thickness of at least one of the plurality of layers of the object obtained by the operation unit,

Thickness measuring device.
The method of claim 5,

The display unit,

Including displaying the thickness obtained by the calculating unit in the contour line,

Thickness measuring device.