KR20230057751A - A folding test system and method integrated with acoustic sensor for measuring critical curvature radius of cover glass for foldable displays - Google Patents

Abstract

The present invention provides a folding test system and a method using an acoustic sensor device to measure critical radius of curvature of cover glass for foldable displays, comprising: a folding test device that performs a folding test on a specimen after fixing both ends of the specimen; and an analysis and measurement device that measures the critical radius of curvature of the specimen based on test results using the folding test device.

Description

A folding test system and method integrated with acoustic sensor for measuring critical curvature radius of cover glass for foldable displays}

The present invention relates to a folding test system and method using an acoustic sensor device for measuring the critical radius of curvature of a cover glass for a foldable display. It relates to a folding test system and method using an acoustic sensor device for accurately measuring the critical radius of curvature of a cover glass by sensitively detecting the breaking sound.

Recently, a flexible display device that can be bent is being developed. Such a flexible display device can be used in a folded or curved form and thus can be used in various fields.

Flexible display devices include a rollable display device that can be rolled like a scroll depending on the degree of bending, a foldable display device that can be folded like paper, and a stretchable display device that can be expanded and reduced in size. are classified as

Among them, the foldable display device has the advantage of being easy to carry when the screen is folded and a large-area display screen can be realized when the screen is unfolded, so its application is expanding to products such as mobile phones and laptop computers.

One of the biggest changes in the commercialization of foldable display devices is the cover window that protects the surface of the OLED panel. Existing cover windows use glass with a thickness of 0.4 to 0.7 mm to secure rigidity, but it is impossible to bend beyond a certain angle, making it difficult to use for foldable display devices.

Accordingly, CPI (Colorless Polyimide) material has been considered as a cover window material for foldable display devices, but CPI has lower optical performance and luxury such as light transmittance and refractive index compared to glass materials, and has lower elasticity (stiffness) and strength. Due to low mechanical properties such as (hardness), permanent deformation due to mechanical stimulation such as folding and scratching easily occurs, and the ability to protect the inside of the device is poor. In addition, since the film may be lifted or the touch sensitivity and visibility may deteriorate, efforts to develop a glass material cover window (hereinafter referred to as cover glass) with excellent flexibility and excellent self- and internal layer protection performance are required to improve product completeness. It is required.

As part of developing the above-described cover glass, there is a technique of measuring the bending diameter (critical curvature radius x 2) when a glass thin film material is broken through a bending (folding) test.

As a method of detecting the moment of fracture, first of all, a method of observing with the naked eye can be considered. Even if the bending speed is as slow as possible, a difference in measured value may occur depending on the tester's proficiency. When it is narrow, there is a problem that it is difficult to detect the moment of breakage with the naked eye.

Next, a method using a laser may be considered, but it is difficult to use this method when the material to be tested is glass having high light transmittance.

Therefore, in order to develop a cover glass that can faithfully perform its original function applied to a foldable display device, a technology that can accurately detect the breaking moment of the cover glass and increase the reliability of measuring the critical bending diameter or critical curvature radius is required. am.

(Patent Document 1) Patent Registration No. 10-2155315 (2020.09.07.)

(Patent Document 2) Patent Publication No. 10-2021-0056102 (May 18, 2021)

An object of the present invention to solve the above problem is to install an acoustic sensor device in a folding test device and measure the critical curvature of the cover glass in order to use the feature of generating a sound of sufficient size at the moment the cover glass is broken through the folding test. It is to provide a folding test system and method using an acoustic sensor device for measuring a radius.

The technical problem to be achieved by the present invention is not limited to the above-mentioned technical problem, and other technical problems not mentioned can be clearly understood by those skilled in the art from the description below. There will be.

The configuration of the present invention for achieving the above object is a folding test apparatus for performing a folding test on the specimen after fixing both ends of the specimen; And an analysis and measuring device for measuring the critical radius of curvature of the specimen based on the test result using the folding test device; an acoustic sensor device for measuring the critical radius of curvature of a cover glass for a foldable display, comprising: Provides a folding test system using

In an embodiment of the present invention, the folding test apparatus includes a support portion seated on the ground; and a fixing member disposed above the support, a movable member disposed above the support to face the fixing member, and positioned at an upper end of the fixing member and an upper end of the movable member to fix the specimen and move the moving member. A pair of specimen fixing members pivotally moving according to the bending of the specimen according to the movement of, a transfer screw shaft connected to the moving member and transmitting power so that the moving member performs a linear motion, and connected to the transfer screw shaft, the Folding test unit including a drive motor for providing rotational power to the feed screw shaft; One surface of the fixing member and the other surface of the movable member facing the one surface of the fixing member are electrically connected to the drive motor for rotating the feed screw shaft, based on the distance the movable member moves according to the rotation of the feed screw shaft. Distance display unit for displaying the separation distance between; an acoustic sensor device installed on the fixing member to measure sound according to the folding test of the specimen; and a control unit for controlling the operation of the folding test unit, wherein the control unit includes a function of setting and controlling folding test conditions and correcting a display error of the separation distance.

In an embodiment of the present invention, the control unit transmits a control signal to the drive motor to rotate the feed screw shaft to control the moving member to move at a constant speed toward the fixing member, and to control the moving member to move at a constant speed. It may be characterized in that by analyzing the sound, the instantaneous moving member in which the breaking sound of the specimen is generated is controlled to stop.

In an embodiment of the present invention, the analyzing and measuring device determines a critical bending diameter from the breaking distance displayed on the distance display unit when the moving member is stopped by the generation of the breaking sound, and the critical bending diameter is It may be characterized in that it is calculated as a critical radius of curvature × 2.

In an embodiment of the present invention, in order to improve the accuracy of the critical bending diameter, a correction value for determining the critical bending diameter is obtained from the fracture separation distance by applying a test video and sound recording method, and the It may be characterized in that the moving speed of the moving member is set to a preset maximum speed within the fracture expected section for the specimen.

In an embodiment of the present invention, the specimen may be a cover glass for a foldable display.

In addition, the configuration of the present invention for achieving the above object is (a) fixing the specimen to the specimen holding member located at the top of the fixing member provided in the folding test apparatus and at the top of the moving member moving toward the fixing member step; (b) The control unit provided in the folding test apparatus controls the moving member to move at a first constant speed so that the separation distance between the fixing member and the moving member approaches the fracture expected section of the specimen, thereby Preparing for the folding test; (c) in a state where it is confirmed that the acoustic sensor device is in operation, a control unit provided in the folding test device controls the movable member to pass through a fracture prediction section at a second constant velocity to perform a folding test on the specimen; and (d) the measuring and analyzing device calculates a critical radius of curvature for the specimen based on the separation distance between the moving member and the fixed member displayed on the distance display unit at the moment when the moving member is stopped by the generation of the breaking sound. It may be characterized by including; measuring step.

The effect of the present invention according to the configuration as described above is to install an acoustic sensor device capable of detecting the sound generated during the folding test for the cover glass to the folding tester so that the momentary moving member generating the breaking sound stops, and the fixing member at this time - The critical radius of curvature of the cover glass can be accurately measured by displaying the separation distance of the movable member on the distance display unit.

The effects of the present invention are not limited to the above effects, and should be understood to include all effects that can be inferred from the detailed description of the present invention or the configuration of the invention described in the claims.

1 is a block diagram showing a folding test system to which an acoustic sensor device for measuring a critical radius of curvature of a cover glass for a foldable display according to an embodiment of the present invention is applied.
2 is a front perspective view showing a folding test system to which an acoustic sensor device for measuring a critical radius of curvature of a cover glass for a foldable display according to an embodiment of the present invention is applied.
3 is a rear perspective view showing a folding test system to which an acoustic sensor device for measuring a critical radius of curvature of a cover glass for a foldable display according to an embodiment of the present invention is applied.
4 is a flowchart illustrating a folding test method using an acoustic sensor device for measuring a critical radius of curvature of a cover glass for a foldable display according to an embodiment of the present invention.
5 is a distance display unit provided in a folding test system to which an acoustic sensor device for measuring a critical radius of curvature of a cover glass for a foldable display according to an embodiment of the present invention is applied, showing the distance between a fixed member and a movable member in a folding test process. It is a side view from one direction showing the separation distance.
6 is a distance display unit provided in a folding test system to which an acoustic sensor device for measuring a critical radius of curvature of a cover glass for a foldable display according to an embodiment of the present invention is applied, between a fixed member and a moving member when the folding test is completed. It is a side view in one direction showing the separation distance of
FIG. 7 is a diagram illustrating that an analysis and measurement device provided in a folding test system to which an acoustic sensor device for measuring a critical radius of curvature of a cover glass for a foldable display according to an embodiment of the present invention is applied analyzes sound.
8 is a diagram illustrating in-depth analysis of sound by an analysis and measurement device provided in a folding test system to which an acoustic sensor device for measuring a critical radius of curvature of a cover glass for a foldable display according to an embodiment of the present invention is applied.

Hereinafter, the present invention will be described with reference to the accompanying drawings. However, the present invention may be embodied in many different forms and, therefore, is not limited to the embodiments described herein. And in order to clearly explain the present invention in the drawings, parts irrelevant to the description are omitted, and similar reference numerals are attached to similar parts throughout the specification.

Throughout the specification, when a part is said to be "connected (connected, contacted, combined)" with another part, this is not only "directly connected", but also "indirectly connected" with another member in between. "Including cases where In addition, when a part "includes" a certain component, it means that it may further include other components without excluding other components unless otherwise stated.

Terms used in this specification are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this specification, terms such as "include" or "have" are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, but one or more other features It should be understood that the presence or addition of numbers, steps, operations, components, parts, or combinations thereof is not precluded.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1. Folding test system (700) applying an acoustic sensor device for measuring the critical radius of curvature of a cover glass for a foldable display

Hereinafter, a folding test system to which an acoustic sensor device for measuring a critical curvature radius of a cover glass for a foldable display according to an embodiment of the present invention is applied with reference to FIGS. 1 to 3 will be described.

1 is a block diagram showing a folding test system to which an acoustic sensor device for measuring a critical radius of curvature of a cover glass for a foldable display according to an embodiment of the present invention is applied. 2 is a front perspective view showing a folding test system to which an acoustic sensor device for measuring a critical radius of curvature of a cover glass for a foldable display according to an embodiment of the present invention is applied. 3 is a rear perspective view showing a folding test system to which an acoustic sensor device for measuring a critical radius of curvature of a cover glass for a foldable display according to an embodiment of the present invention is applied.

1 and 2, the folding test system 700 to which the acoustic sensor device for measuring the critical radius of curvature of a cover glass for a foldable display according to an embodiment of the present invention is applied is a folding test device 100, an image and a sound recording device 200 and an analysis and measuring device 300.

The folding test apparatus 100 fixes both ends of the specimen 10 and performs a folding test on the specimen 10. Here, the specimen 10 is a cover glass for a foldable display.

The folding test apparatus 100 for this purpose includes a support part 110, a folding test part 120, a distance display part 130, a control unit 150, a driving motor 160, a specimen support part 170, and an acoustic sensor device 400. includes

Referring to FIGS. 2 and 3 , the support 110 may be a flat plate having a predetermined thickness to be placed on the ground.

2 and 3, the folding test unit 120 includes a fixing member 121, a moving member 122, a guide shaft 123, a feed screw shaft (ball screw) 124, and a specimen fixing member 125 ) And a guide shaft fixing part 126.

The fixing member 121 and the moving member 122 are arranged to face each other on the upper part of the support part 110, and the two facing surfaces are parallel and perpendicular to the feed screw shaft 124 and the support part 110.

In addition, a pair of guide shafts 123 parallel to the support 110 are inserted at both sides of the lower portion of the moving member 122, and a pair of guide shafts 123 are parallel to the lower center of the moving member 122. A screw shaft 124 is inserted.

Both sides of the pair of guide shafts 123 are fixed to the fixing member 121 and the guide shaft fixing member 126, respectively, and one side of the feed screw shaft 124 is inserted into the bearing fixed to the fixing member 121, and the other The side portion is fixed to the drive motor 160 shaft.

The moving member 122 is moved along a pair of guide shafts 123 by the feed screw shaft 124 toward the fixing member 121 to reach a previously set position, but the specimen 10 Stop at the moment of breakage.

That is, the movable member 122 moves toward the fixing member 121 from a distance from the fixing member 121 to a position close to the fixing member 121 in order to fix the initial specimen 10 to the specimen fixing member 125. It moves and stops when the specimen 10 is broken in the process.

A pair of specimen holding members 125 are located at the top of the fixing member 121 and the top of the moving member 122, respectively, but the facing surfaces of the fixing member 121 and the moving member 122 and the support 110 It is arranged in parallel to fix the specimen 10 and pivots so that the specimen 10 is naturally bent in the direction of the support 110 according to the movement of the movable member 122 .

The guide shaft fixing part 126 is coupled to the upper surface of the support part 110 while being positioned between the moving member 122 and the driving motor 160 .

In addition, a hole is formed in the central portion of the guide shaft fixing part 126 so that the feed screw shaft 124 passes without contact.

The distance display unit 130 is electrically connected to the driving motor 160 that rotates the feed screw shaft 124, and the fixing member 121 is based on the distance the moving member 122 moves according to the rotation of the driving motor 160. ) and the separation distance between the facing surfaces of the movable member 122.

The control unit 150 controls the operation of the folding test unit 120 and the video and sound recording device 200 .

The control unit 150 transmits a first control signal to the driving motor 160 to control the moving member 122 to move toward the fixing member 121 at a first constant speed by the rotation of the feed screw shaft 124. do.

On the other hand, when the movable member 122 moves at the first uniform velocity and enters the fracture prediction section, the controller 150 starts video and sound recording and simultaneously transmits a second control signal to the drive motor 160 to transfer. The rotation of the screw shaft 124 controls the moving member 122 to move toward the fixing member 121 at a second constant velocity. Here, the fracture prediction interval is a value obtained and set through a preliminary folding test on a similar specimen, and may vary depending on the material, thickness, processing conditions, etc. of the specimen.

Also, the second constant velocity is slower than the first constant velocity. The above reason is to accurately measure the fracture point of the specimen 10, that is, the critical radius of curvature.

Additionally, the control unit 150 may include a function of setting and controlling folding test conditions and correcting display errors of the separation distance.

The driving motor 160 rotates the feed screw shaft 124 according to a signal received from the controller to linearly move the moving member 122 toward the fixing member 121 .

Specifically, when the driving motor 160 receives the first control signal or the second control signal from the controller, the moving member 122 rotates the feed screw shaft 124 according to the first control signal or the second control signal. is linearly moved toward the fixing member 121.

The specimen support 170 may be used for the purpose of facilitating the fixing work by preventing the specimen 10 from being bent downward by its own weight when the specimen 10 is fixed to the specimen holding member 125, and the specimen support holding member 171 ) and a specimen support moving member 172.

As shown in FIGS. 2 and 3 , the specimen support holding member 171 is coupled to the upper surface of the support 110 and is positioned behind the fixing member 121 and the moving member 122 .

The specimen support movable member 172 is located above the specimen support holding member 171 and can slide back and forth.

In order to fix the specimen 10 to the specimen fixing member 125, the fixing member 121 and the moving member 122 are spread apart as much as the width of the specimen, and the specimen supporting moving member 172 is moved therebetween, and the specimen fixing member ( The upper surface(s) of 125) is horizontal with the upper surface of the specimen supporting moving member 172.

Thereafter, the specimen 10 is placed in the middle of the specimen support movable member 172 in the longitudinal direction, and both ends are fixed to the fixing member 121 using a tape having an adhesive force that is not excessively large, and when this work is completed, the specimen is supported. By moving the movable member 172 back, it is prevented from being caught when the movable member 122 moves in the direction of the fixing member 121 for the folding test.

The origin detecting unit 180 includes an origin detecting movable member 181 and an origin detecting sensor member 182 .

The origin detecting moving member 181 is coupled to one side of the moving member 122 and moves together with the moving member 122, at the sensing position of the detection sensor member 182 coupled to the upper surface of the origin adjusting unit 190. When it reaches, the control unit 150 recognizes that the moving member 122 is at the preset origin position (eg, 220 mm).

The origin adjusting unit 190 is a micro stage and includes a base 191, a sliding member 192, a distance adjusting member 193, and a tightening member 194.

The origin control unit 190 is located at the rear of the upper surface of the support part 110 so that the detection sensor member 182 coupled to the upper surface of the sliding member 192 is spaced apart from one surface of the fixing member 121 by a predetermined distance (eg, 220 mm). install

The sliding member 192 is located on the upper surface of the base 191 and slides left and right on the upper surface of the base 191 according to the adjustment of the distance adjusting member 193 .

Move the movable member 122 into the fracture prediction section and measure the separation distance between one side and the other side of the fixing member 121 with a precision distance measuring device (resolution 0.01 mm or less) and compare with the value displayed on the distance display unit, If there is a difference, the distance adjusting member 193 is rotated (by moving the detection sensor member) so that there is no difference.

The above-described origin sensing unit 180 and origin adjusting unit 190 are components for controlling the origin to increase the accuracy of displaying the separation distance between the fixed member 121 and the moving member 122, and in the present invention, The origin is adjusted so that the movable member 122 has a predetermined separation distance (eg, 220 mm) from the fixing member 121 by the components.

The acoustic sensor device 400 includes an acoustic sensor support 410 and an acoustic sensor 420 .

The acoustic sensor 420 is fixed to one surface of the acoustic sensor support 210, and the acoustic sensor support 210 is located on the back side of the fixing member 121 so that the acoustic sensor 420 is adjacent to the position where the specimen 10 is broken. formed on the surface opposite to the contacted surface).

In the fixing member 121, a long fixing member hole 121a is drilled in the vertical direction at the center of the left and right directions so that the breaking sound of the specimen is well transmitted to the acoustic sensor 420.

In addition, the acoustic sensor support 410 allows the acoustic sensor 420 fixed on one surface to be moved in the vertical direction so that the acoustic sensor 420 can be brought close to the folding and breaking position that varies depending on the size of the specimen 10 .

The video and sound recording device 200 records the video and sound of the folding test process for the specimen 10 using the folding test device 100.

At this time, the sound includes the sound generated when the specimen 10 is broken by the folding test, and the image includes images of the support part 110, the folding test part 120, and the distance display part 130.

The reason for recording the test process with the video and sound recording device 200 in the present invention is the time when the moving member 122 stops when the acoustic sensor device 400 detects the sound generated by the specimen 10 breaking during the test. Check whether the time when the actual sound is issued coincides with, and if it does not match, correct the separation distance displayed on the distance display unit 130 when the moving member 122 stops to accurately measure the critical curvature radius of the specimen 10 It is for

As shown in FIG. 2, the above-described video and sound recording device 200 is located facing the front of the folding test device 100, and records the support unit 110, folding test unit 120, and distance display unit in real time during the test. After the end of the test, the video and sound for (130) are transmitted to the analysis and measurement device (300).

The analysis and measurement device 300 analyzes the separation distance transmitted from the distance display unit 130 and the image and sound transmitted from the video and sound recording device 200 to determine the fixing member 121 at the moment the specimen 10 is broken. The separation distance between the and the movable member 122, that is, the critical curvature diameter (critical curvature radius x 2) of the specimen is measured. As a result of video and sound analysis of multiple tests, when it is confirmed that the break point and the stop point of the movable member 122 coincide, the separation distance correction process through test video and analysis can be omitted.

2. Folding test method using acoustic sensor device for measuring critical curvature radius of cover glass for foldable display

Hereinafter, a folding test method using an acoustic sensor device for measuring a critical radius of curvature of a cover glass for a foldable display according to an embodiment of the present invention will be described with reference to FIGS. 1 to 8 .

4 is a flowchart illustrating a folding test method using an acoustic sensor device for measuring a critical radius of curvature of a cover glass for a foldable display according to an embodiment of the present invention.

Referring to FIG. 4, a folding test method using an acoustic sensor device for measuring a critical radius of curvature of a cover glass for a foldable display according to an embodiment of the present invention is (a) a fixing member provided in the folding test device 100 Fixing the specimen 10 to the specimen fixing member 125 located at the top of the 121 and the top of the moving member 122 moving toward the fixing member 121 (S100), (b) folding test device The control unit 150 provided in the 100 controls the movable member 122 to move at a first uniform velocity so that the separation distance between the fixing member 121 and the movable member 122 is within the expected fracture section of the specimen 10. Preparing for a folding test on the specimen 10 so as to approach (S200), (c) in a state where it is confirmed that the acoustic sensor device 400 is in operation, the control unit 150 provided in the folding test device 100 is a moving member (S300) proceeding with the folding test on the specimen 10 by controlling the 122 to pass through the fracture expected section at a second constant velocity (S300), (d) when the specimen 10 is broken and a sound of a certain size or more is generated, the control unit The step of stopping the moving member 122 and (e) the measuring and analyzing device 300, the moving member 122 displayed on the distance display unit 130 at the moment when the moving member 122 is stopped by the generation of the breaking sound and measuring a critical radius of curvature of the specimen 10 based on the separation distance between the and the fixing member 121 (S400).

5 is a distance display unit provided in a folding test system to which an acoustic sensor device for measuring a critical radius of curvature of a cover glass for a foldable display according to an embodiment of the present invention is applied, showing the distance between a fixed member and a movable member in a folding test process. It is a side view from one direction showing the separation distance. 6 is a distance display unit provided in a folding test system to which an acoustic sensor device for measuring a critical radius of curvature of a cover glass for a foldable display according to an embodiment of the present invention is applied, between a fixed member and a moving member when the folding test is completed. It is a side view in one direction showing the separation distance of FIG. 7 is a diagram illustrating that an analysis and measurement device provided in a folding test system to which an acoustic sensor device for measuring a critical radius of curvature of a cover glass for a foldable display according to an embodiment of the present invention is applied analyzes sound. 8 is a diagram showing that an analysis and measurement device provided in a folding test system to which an acoustic sensor device for measuring a critical radius of curvature of a cover glass for a foldable display according to an embodiment of the present invention is applied performs an in-depth analysis of sound.

Here, the analysis information includes the breaking sound, which is the sound when the specimen 10 is broken, and the separation distance at the time when the breaking sound is generated.

In addition, the breaking sound is a sound that is greater than the sound of a certain size generated from the specimen 10 and the folding test apparatus 100 before the specimen 10 is broken, and the sound peak in FIG. 7 and the waveform in FIG. I mean the big part.

Specifically, the analysis and measurement device 300 determines (measuring) the critical curvature diameter (= critical curvature radius X 2) by finding the separation distance obtained from the video and sound recording device 200 at the moment when the breaking sound occurs.

In summary, after the specimen 10 is fixed to the specimen holding member 125 at the top of the fixing member 121 and the moving member 122 in an unfolded state, the control unit 150 transmits a control signal to the motor unit 160. When the movable member 122 moves linearly toward the fixing member 121 at the first uniform velocity, the fixed specimen 10 is bent in a 'U' shape in the direction of the support 110, and between the movable member and the fixing member When the separation distance approaches the expected fracture section of the specimen, preparation for the folding test for the specimen 10 is completed, and the video and audio recording device 200 displays the support 110, the folding test unit 120, and the separation distance. The video and sound included in the distance display unit 130 are recorded in real time.

Next, when the control unit 150 transmits a second control signal to the motor unit 160 to control the moving member 122 to move at a second constant speed, a folding test is performed on the specimen 10, and the specimen 10 ) is broken to generate a sound of a certain size or more, the movement of the moving member 122 is stopped.

Next, the analysis and measurement device 300 analyzes the separation distance displayed on the distance display unit 130 when the sound and the moving member 122 are stopped.

Specifically, the analysis and measurement device 300 analyzes the sound in the test process to find the starting point (breaking point P _f ) of the breaking sound having the largest amplitude among the acquired sounds, and at this time, the separation distance displayed on the distance display unit. Determines the critical radius of curvature for the specimen 10.

The above description of the present invention is for illustrative purposes, and those skilled in the art can understand that it can be easily modified into other specific forms without changing the technical spirit or essential features of the present invention. will be. Therefore, the embodiments described above should be understood as illustrative in all respects and not limiting. For example, each component described as a single type may be implemented in a distributed manner, and similarly, components described as distributed may be implemented in a combined form.

The scope of the present invention is indicated by the following claims, and all changes or modifications derived from the meaning and scope of the claims and equivalent concepts should be interpreted as being included in the scope of the present invention.

100: folding test device
110: support
120: folding test unit
121: fixing member
121a: fixing member hole
122: moving member
123: guide axis
124: feed screw axis
125: specimen holding member
126: guide shaft fixing part
130: distance display unit
150: control unit
160: drive motor
170: specimen support
171: specimen support member
172: specimen support movable member
180: origin detection unit
181: origin sensing moving member
182: origin detection sensor member
190: origin control unit
191: base
192: sliding member
193: distance adjusting member
194: fastening member
300: analysis and measuring device
400: acoustic sensor device
410: acoustic sensor support
420: acoustic sensor
700: Folding test system applying an acoustic sensor device for measuring the critical radius of curvature of a cover glass for a foldable display

Claims (8)

After fixing both ends of the specimen, a folding test device performing a folding test on the specimen; and
An acoustic sensor device for measuring the critical radius of curvature of a cover glass for a foldable display comprising an analysis and measuring device for measuring the critical radius of curvature of the specimen based on the test results using the folding test device. Applied folding test system.
According to claim 1,
The folding test device,
A support that is seated on the ground; and
A fixing member disposed on the upper portion of the support, a moving member disposed on the upper portion of the support to face the fixing member, and positioned at an upper end of the fixing member and an upper end of the moving member to fix the specimen and A pair of specimen fixing members pivotally moving according to the bending of the specimen according to movement, a feed screw shaft connected to the moving member and linearly moving the moving member, and a drive connected to the feed screw shaft to rotate the feed screw shaft A folding test system using an acoustic sensor device for measuring a critical radius of curvature of a cover glass for a foldable display, comprising: a folding test unit including a motor.
According to claim 2,
The folding test device,
Displays the separation distance between one surface of the fixing member and the other surface of the movable member facing the one surface of the fixing member based on the distance moved by the movable member electrically connected to the drive motor according to the rotation of the feed screw shaft a distance display unit;
an acoustic sensor device installed on the fixing member to measure sound according to the folding test of the specimen; and
Including; a control unit for controlling the operation of the folding test unit;
The control unit includes a function of setting and controlling folding test conditions and correcting a display error of the separation distance.
According to claim 3,
The control unit transmits a control signal to the driving motor to rotate the feed screw shaft to control the moving member to move toward the fixing member at a constant speed, and to analyze the sound transmitted from the acoustic sensor device to break the specimen. A folding test system applying an acoustic sensor device for measuring the critical radius of curvature of a cover glass for a foldable display, characterized in that it controls the momentary moving member to stop when sound is generated.
According to claim 4,
When the moving member is stopped by the generation of the breaking sound, the analyzing and measuring device determines a critical folding diameter from the breaking distance displayed on the distance display unit,
The critical bending diameter is a folding test system applying an acoustic sensor device for measuring the critical radius of curvature of a cover glass for a foldable display, characterized in that calculated as a critical radius of curvature ⅹ2.
According to claim 5,
In order to improve the accuracy of the critical bending diameter, a correction value for determining the critical bending diameter is obtained from the breaking separation distance by applying a test video and sound recording method, and the fracture prediction section for the specimen set through the preliminary test A folding test system applying an acoustic sensor device for measuring the critical radius of curvature of a cover glass for a foldable display, characterized in that for setting the moving speed of the moving member to a preset minimum speed within.
According to claim 1,
The specimen is a folding test system applying an acoustic sensor device for measuring the critical radius of curvature of a cover glass for a foldable display, characterized in that the cover glass for a foldable display.
(a) fixing a specimen to a specimen holding member positioned at an upper end of a fixing member provided in a folding test apparatus and at an upper end of a movable member moving toward the fixing member;
(b) The control unit provided in the folding test apparatus controls the moving member to move at a first constant speed so that the separation distance between the fixing member and the moving member approaches the fracture expected section of the specimen, thereby Preparing for the folding test;
(c) in a state where it is confirmed that the acoustic sensor device is in operation, a control unit provided in the folding test device controls the movable member to pass through a fracture prediction section at a second constant velocity to perform a folding test on the specimen;
(d) stopping the movable member 122 by a control unit when the specimen 10 is broken and a sound of a certain level or more is generated; and
(e) The measurement and analysis device measures the critical radius of curvature of the specimen based on the separation distance between the moving member and the fixed member displayed on the distance display unit at the moment the moving member is stopped by the generation of the breaking sound. A folding test method using an acoustic sensor device for measuring the critical radius of curvature of a cover glass for a foldable display, comprising the steps of:

Images