An on-line cleaning apparatus for TFT glass ribbon

Abstract

This invention discloses an online cleaning device for TFT glass strips, relating to the field of TFT glass production technology. It includes a water tank, an ultrasonic generator, a heating device, and a conveyor roller assembly. The water tank is positioned at the front end of a defect detection system. The ultrasonic generator generates ultrasonic waves within the water tank. The heating device heats the water in the tank. As the glass strip moves with the conveyor roller assembly, when it reaches the water tank position, the height of the descending roller assembly decreases, causing the glass strip to sag under gravity until it is submerged below the surface of the cleaning fluid. Any debris adhering to the glass strip is effectively removed after ultrasonic cleaning. When the glass strip detaches from the cleaning fluid, a blower forms an air knife to remove any remaining debris, causing it to return to the cleaning fluid pool and effectively ensuring the cleaning effect of the glass strip.

Description

Technical Field

[0001] This invention relates to the field of TFT glass production technology, and more specifically to an online cleaning device for TFT glass strips. Background Technology

[0002] TFT glass is a crucial component in the manufacture of liquid crystal displays (LCDs). It consists of a glass substrate and an array of thin-film transistors (TFTs) on top of it. The main function of TFT glass is to control the alignment of liquid crystal molecules, thereby determining the display effect of the LCD. The manufacturing process of TFT glass is very complex, requiring multiple steps. First, an ITO thin film is deposited on the glass substrate as a conductive layer. Then, the TFT array is formed through processes such as photolithography and etching. High-precision equipment and process control technologies are required to ensure the quality and performance of the TFT array. The quality and performance of the TFT glass have a critical impact on the display effect of the LCD. If the TFT glass is defective or performs poorly, it can lead to problems such as uneven brightness, color distortion, and slow response time in the LCD. Therefore, during LCD manufacturing, strict quality control and testing of the TFT glass are necessary to ensure that its quality and performance meet requirements.

[0003] In the TFT glass production process, to effectively detect and monitor its processing quality, an automatic surface defect detection system has been added to existing production lines to detect surface defects in the TFT glass. However, in actual production, the applicant found that the existing detection system has many false positives and a low detection accuracy rate. Furthermore, simply increasing the detection accuracy of the system may cause the system program to malfunction and freeze. Summary of the Invention

[0004] The technical problem solved by this invention is that existing detection systems have many misjudgments and low detection accuracy, while simply increasing the detection accuracy of the detection system may cause the detection system program to freeze.

[0005] The objective of this invention can be achieved through the following technical solutions:

[0006] An online cleaning device for TFT glass ribbons, comprising:

[0007] A water tank, located at the front end of the defect detection system, contains cleaning fluid.

[0008] An ultrasonic generator for generating ultrasonic waves within the water tank.

[0009] A heating device is used to heat the cleaning solution in the water tank to ensure that the cleaning solution is maintained within a specified temperature range;

[0010] The conveying roller assembly is divided into a descending roller assembly and an ascending roller assembly in the water tank area. The ascending roller assembly and the descending roller assembly are symmetrically arranged. The height of multiple roller tracks in the descending roller assembly decreases sequentially, while the height of multiple roller tracks in the ascending roller assembly increases sequentially. The apex of the roller track with the lowest height in the descending roller assembly and the ascending roller assembly is located below the surface of the cleaning liquid.

[0011] In one aspect of the present invention, the number of the descending roller group and the ascending roller group are each at least three.

[0012] In one embodiment of the present invention: the height difference between the roller track with the highest height and the roller track with the lowest height in the descending roller group is 100mm.

[0013] In one embodiment of the present invention: a water inlet hole is provided on the side of the water tank, and a drain hole is provided at the bottom of the water tank, with the water inlet hole located above the drain hole.

[0014] In one aspect of the invention: the outlet of the drain hole is connected to a water treatment mechanism, which is used to purify the water in the tank.

[0015] In one aspect of the present invention: a conductivity sensor is installed in the water tank. The conductivity sensor is used to collect the conductivity information of the cleaning liquid in the water tank and transmit it to the controller. When the conductivity in the water tank reaches a threshold, the controller issues a command, and the water treatment mechanism starts to purify the cleaning liquid in the water tank.

[0016] In one embodiment of the present invention: a fan is provided on the upper and lower sides of the glass strip, the air outlet of the fan is facing the position where the glass strip separates from the cleaning liquid, and the airflow direction is opposite to the movement direction of the glass strip.

[0017] In one aspect of the invention: at the point where the airflow contacts the glass strip, the direction of the airflow is tangent to the arc trajectory of the glass strip.

[0018] In one aspect of the present invention: the width of the water tank is greater than the width of the glass strip, the direction of the air outlet is inclined in the lateral direction relative to the moving direction of the glass strip, and the inclination directions of the air outlets located on the upper and lower sides of the glass strip are opposite.

[0019] In one embodiment of the present invention, the cleaning solution is water.

[0020] An online cleaning device for TFT glass ribbons according to the present invention has at least one of the following technical effects:

[0021] An ultrasonic generator produces ultrasonic waves within the water tank, while a heating device heats the water to maintain the cleaning solution temperature within the process standards, preventing the glass belt from breaking due to excessively low water temperature. As the glass belt moves with the conveyor rollers, it descends under gravity as the roller track height decreases until it is submerged below the cleaning solution surface. Any adhering debris on the glass belt is effectively removed after ultrasonic cleaning. When the glass belt detaches from the cleaning solution, a blower creates air blades to remove any remaining debris (such as particles and water droplets) that may have been carried with it, causing it to return to the cleaning solution pool and ensuring effective cleaning. Simultaneously, a water treatment system ensures the purity of the cleaning solution, guaranteeing the cleaning effect.

[0022] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0023] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0024] Figure 1 This is a schematic diagram of the structure of the present invention used in a production line;

[0025] Figure 2 This is a schematic diagram of the overall structure of the present invention;

[0026] Figure 3 This is a schematic diagram of the structure of the fan section of the present invention;

[0027] Figure 4 This is a schematic diagram of the structure of the glass strip of the present invention with the diversion direction tilted when viewed from above.

[0028] In the diagram: 1. Water tank; 2. Ultrasonic generator; 3. Water treatment mechanism; 4. Lowering roller assembly; 5. Rising roller assembly; 6. Water injection hole; 7. Drainage hole; 8. Fan. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0031] In the description of this invention, "several" means one or more, "more than" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0032] In the TFT glass production process, to effectively detect and monitor processing quality, existing production lines have incorporated automatic surface defect detection systems to identify surface defects in the TFT glass. However, during actual production, the applicant discovered that the existing detection system suffers from numerous misjudgments and a low accuracy rate. Simply increasing the detection system's precision could lead to system program crashes. Research revealed that during TFT glass production, a large amount of dust, tin ash, and other contaminants are generated on the glass strip during glass melt forming and annealing. Dust from equipment operation and the environment itself can also settle on the glass strip. This situation can cause the surface defect detection system to misjudge. Increasing the detection system's precision could lead to system program crashes due to the presence of excessive dust (potentially causing the system to detect too many defects), severely impacting production efficiency. Furthermore, the presence of dust or other particulate matter can negatively affect subsequent processing steps, further reducing the glass yield.

[0033] Please see Figure 1-4This invention relates to an online cleaning device for TFT glass strips, comprising a water tank 1, an ultrasonic generator 2, a heating device, and a conveying roller assembly. The water tank 1 is positioned at the front end of a defect detection system used to detect surface defects in the TFT glass strip. The water tank 1 is fixedly supported by a support structure and contains a cleaning solution, which can be clean water, for cleaning impurities from the TFT glass strip. The conveying roller assembly includes several stainless steel roller tracks for conveying the TFT glass strip. The high points of these roller tracks form the conveying surface of the TFT glass strip. The portion of the conveying roller assembly located in the water tank 1 area is divided into a descending roller assembly 4 and an ascending roller assembly 5, which are symmetrically arranged. The heights of the roller tracks in the descending roller assembly 4 decrease sequentially, while the heights of the roller tracks in the ascending roller assembly 5 increase sequentially. The highest roller track in the descending roller assembly 4 and the ascending roller assembly 5 is level with the other roller tracks, and the apex of the lowest roller track in the descending roller assembly 4 and the ascending roller assembly 5 is below the surface of the cleaning solution. The ultrasonic generator 2 is used to generate ultrasonic waves in the water tank 1 to effectively clean particulate impurities on the TFT glass strip. The heating device serves as a heat source for the cleaning fluid in the water tank 1, ensuring that the cleaning fluid is maintained within a certain temperature range to prevent the TFT glass strip from breaking due to temperature differences when it enters the cleaning fluid. Furthermore, a temperature sensor and controller can be installed for online monitoring and control of the cleaning fluid temperature.

[0034] Please see Figure 1-2In one embodiment of the present invention, the number of descending roller group 4 and ascending roller group 5 can be three, four, five, or more, respectively. The accompanying drawings show three rollers as an example, meaning there are six roller tracks within the water tank 1 area. The height of the highest roller track at both ends corresponds to the height of the roller tracks at the input and output ends, respectively. The two lowest roller tracks in the descending roller group 4 and ascending roller group 5 are at equal heights and below the surface of the cleaning fluid, allowing the glass belt to be in a planar state between these two roller tracks for better cleaning. In actual use, the surface of the cleaning fluid can also cover more roller tracks (within the water tank 1 area). Here, we take eight roller tracks within the water tank 1 area as an example, meaning there are four descending roller groups 4 and four ascending roller groups 5. Among the four drive rollers of the descending roller group 4, starting from the second drive roller, the roller platform elevation decreases in a stepped manner relative to the previous drive roller, with a 100mm difference between the elevation of the first and fourth drive rollers. The four drive rollers in the ascending roller group 5 are arranged symmetrically with the four drive rollers in the descending roller group 4, using a vertical plane as the plane of symmetry. That is, the elevation of the four drive rollers in the ascending roller group 5 increases in a stepped manner relative to the preceding drive roller. The elevation of the highest roller track differs from that of the lowest roller track by 100mm. This allows the glass ribbon to naturally sag due to gravity after entering the water tank 1 area, concave within the water tank 1 area, and able to be submerged in the cleaning solution, thereby utilizing ultrasonic waves to clean the adhering substances on the glass ribbon.

[0035] Please see Figure 1-2In one embodiment of the present invention, a water inlet 6 is provided on the side of the water tank 1, and a drain hole 7 is provided at the bottom of the water tank 1. By providing the water inlet 6 and drain hole 7, the cleaning solution in the water tank 1 can be replaced after it becomes turbid to a certain extent. The water inlet 6 is located above the drain hole 7, ensuring that the injected clean water is at the top, which is more conducive to improving the cleaning effect on the glass ribbon and carrying the cleaned-off deposits to the drain hole 7. Furthermore, the outlet of the drain hole 7 is connected to a water treatment mechanism 3, which is used to purify the water in the water tank 1. The cleaning solution can be purified by the water treatment mechanism 3, allowing it to be recycled until the water treatment mechanism 3 can no longer purify the cleaning solution to meet usage requirements, at which point the cleaning solution is completely replaced. The water treatment mechanism 3 can purify the cleaning solution by filtration, sedimentation, adsorption, etc. The turbid cleaning solution is transported to the water treatment mechanism 3 through the drain hole 7 for purification, and the purified cleaning solution is transported back to the water tank 1 through the water inlet 6. Furthermore, a sensor can be installed in the water tank 1 to collect information on the turbidity of the cleaning solution. The sensor is connected to a controller. When the turbidity of the cleaning solution reaches a preset value, the controller sends a signal to the water treatment mechanism 3 to start purifying the cleaning solution in the water tank 1. This continues until the turbidity of the cleaning solution in the water tank 1 decreases to the required level. If, after a certain period of purification, the turbidity of the cleaning solution remains high or abnormal, an instruction is issued to completely replace the cleaning solution, or appropriate treatment measures are taken after manual inspection and confirmation. The turbidity of the cleaning solution can be monitored by a sensor or a conductivity meter. The conductivity threshold can be set according to actual working conditions, i.e., based on the influence trend of the main components of particulate matter in the environment dissolving in water on conductivity under different usage scenarios. As the deposits on the glass ribbon enter the cleaning solution, the turbidity of the cleaning solution increases, and its conductivity will change. The conductivity threshold can be determined based on the type of main particles in the environment in which this application is used (i.e., particles that will adhere to the glass ribbon). That is, the conductivity threshold corresponding to the turbidity threshold is determined based on whether the conductivity increases or decreases after the particles enter the cleaning solution.

[0036] Please see Figure 1-3In one embodiment of the present invention, after the glass belt is cleaned, it is positioned on the rising roller group 5. During the height lifting process, when the glass belt is about to detach from the cleaning liquid, some impurities may be adsorbed on the glass belt (i.e., there may be attached substances on the glass belt, such as dust particles dissolved in water, water droplets, etc., which may cause adverse effects in subsequent processes). In particular, the upper surface of the glass belt may carry out suspended particles in the cleaning liquid when it detaches from the cleaning liquid during the rising process. To avoid this problem, fans 8 are respectively provided on the upper and lower sides of the glass belt. The air outlet of the fan 8 faces the position where the glass belt detaches from the cleaning liquid (i.e., the position where the glass belt is located inside and outside the cleaning liquid in the windless state). The direction of the air outlet can be slightly offset upward relative to the dividing line position. During the process of the glass belt detaching from the cleaning liquid, the air outlet of the fan 8 forms an air knife at the detachment dividing line position of the glass belt and the cleaning liquid. The airflow direction is opposite to the movement direction of the glass belt, thereby blowing the impurities that may be carried out of the cleaning liquid by the glass belt back into the cleaning liquid, thereby ensuring the cleaning effect of the glass belt. Furthermore, to ensure the uniformity of the blower airflow, a duct can be installed along the width of the glass strip, with multiple air outlets evenly distributed on the side of the duct. At the point where the airflow contacts the glass strip, the airflow direction can be tangent to the arc trajectory of the glass strip, thereby ensuring the blowing effect and avoiding any impact on the surface quality of the glass strip.

[0037] Please see Figure 1-4In one embodiment of the present invention, the width of the water tank 1 is greater than the width of the glass strip, so as to form a flow space for the cleaning liquid on both sides of the glass strip, avoiding the glass strip from separating the cleaning liquid above it, resulting in poor flow of the cleaning liquid above and below the glass strip, and thus causing the cleaning liquid above the glass strip to have higher turbidity. Furthermore, from a top view, the air outlet is inclined, and the air outlets on the upper and lower sides of the glass strip are inclined in opposite directions, so that the airflow is inclined to a certain extent relative to the forward direction of the glass strip. This inclined air force can blow away any adhering objects that may be carried out by the glass strip, while also generating a certain force on the cleaning liquid along the width direction of the glass strip (the direction of glass strip movement is the length direction), thereby improving the flow of the cleaning liquid on the upper and lower surfaces of the glass strip, and thus carrying the dissolved impurities above the glass strip to the lower part of the glass strip for sedimentation. Because the upper surface of the glass ribbon is more prone to adhering to impurities than the lower surface, the cleaning solution above the glass ribbon will contain more dissolved substances during cleaning. If the flow of the cleaning solution is not enhanced, these dissolved substances will be carried to the lower surface of the glass ribbon. This will result in three problems: firstly, the cleaning solution above the glass ribbon will be relatively turbid; secondly, the dissolved substances will settle and fall back onto the glass ribbon; and thirdly, the glass ribbon moves obliquely upwards when detaching from the cleaning solution, potentially carrying away the dissolved substances. Therefore, by tilting the air outlet, the flow of the cleaning solution on both the upper and lower surfaces of the glass ribbon is improved, thus ensuring effective cleaning. The air outlet located above the glass ribbon can be divided into two layers. The upper layer acts on the liquid surface (slightly below the boundary line), with a slightly increased airflow to create a fixed flow of the cleaning solution, while avoiding any impact on the width direction of the glass ribbon. The lower layer faces the boundary line and is mainly used to blow away adhering substances, allowing them to return to the cleaning solution and preventing them from moving with the glass ribbon and causing negative impacts in subsequent processes. Furthermore, the fan can be configured as an adjustable structure to allow for adjustment of the air outlet angle as needed.

[0038] The working principle of this invention is as follows: The ultrasonic generator 2 generates ultrasonic waves in the water tank 1. The heating device heats the water in the water tank 1 to maintain the temperature of the cleaning solution within the process standard, preventing the glass belt from breaking due to excessively low water temperature. As the glass belt moves with the conveyor roller group, when it reaches the position of the water tank 1, the height of the roller track of the descending roller group 4 decreases. Under the action of gravity, the glass belt droops down with the decrease in roller track height until it is submerged below the surface of the cleaning solution. Any impurities that may be attached to the glass belt are effectively removed after ultrasonic cleaning. When the glass belt detaches from the cleaning solution, the blower 8 forms an air knife to blow away any adhering substances (such as particles, water droplets, etc.) that may be carried with the glass belt when it detaches from the cleaning solution, causing the adhering substances to return to the cleaning solution pool, effectively ensuring the cleaning effect of the glass belt. At the same time, the water treatment mechanism 3 is used to ensure the purity of the cleaning solution and guarantee the cleaning effect.

[0039] The foregoing has provided a detailed description of one embodiment of the present invention, but this description is merely a preferred embodiment and should not be construed as limiting the scope of the invention. All equivalent variations and modifications made within the scope of the claims of this invention should still fall within the scope of the claims.

Claims

1. An online cleaning device for TFT glass ribbons, characterized in that, include: Water tank (1), the water tank (1) is set at the front end of the defect detection system, and the water tank (1) contains cleaning fluid; An ultrasonic generator (2) is used to generate ultrasonic waves in the water tank (1). A heating device is used to heat the cleaning liquid in the water tank (1) to ensure that the cleaning liquid is maintained within a specified temperature range in order to prevent the glass ribbon from breaking due to low water temperature. The conveying roller group is divided into a descending roller group (4) and an ascending roller group (5) in the water tank (1) area. The ascending roller group (5) and the descending roller group (4) are symmetrically arranged. The height of multiple roller tracks in the descending roller group (4) decreases sequentially, and the height of multiple roller tracks in the ascending roller group (5) increases sequentially. The apex of the roller track with the lowest height in the descending roller group (4) and the ascending roller group (5) is below the liquid surface of the cleaning liquid. The number of the descending roller group (4) and the ascending roller group (5) are at least three; the height difference between the roller with the highest height and the roller with the lowest height in the descending roller group (4) is 100mm; a fan (8) is provided on the upper and lower sides of the glass belt respectively, the air outlet of the fan (8) is facing the position where the glass belt separates from the cleaning liquid, and the airflow direction is opposite to the moving direction of the glass belt; at the position where the airflow contacts the glass belt, the airflow direction is tangent to the arc trajectory of the glass belt.

2. The online cleaning equipment for TFT glass ribbons according to claim 1, characterized in that, The side of the water tank (1) is provided with a water inlet hole (6) and the bottom of the water tank (1) is provided with a drain hole (7). The water inlet hole (6) is located above the drain hole (7).

3. The online cleaning equipment for TFT glass ribbons according to claim 2, characterized in that, The outlet of the drain hole (7) is connected to the water treatment mechanism (3), which is used to purify the water in the water tank (1).

4. The online cleaning equipment for TFT glass ribbons according to claim 3, characterized in that, A conductivity sensor is installed in the water tank (1). The conductivity sensor is used to collect the conductivity information of the cleaning liquid in the water tank (1) and transmit it to the controller. When the conductivity in the water tank (1) reaches the threshold, the controller issues a command and the water treatment mechanism (3) starts to purify the cleaning liquid in the water tank (1).

5. The online cleaning equipment for TFT glass ribbons according to claim 4, characterized in that, The width of the water tank (1) is greater than the width of the glass strip. The direction of the air outlet is tilted in the horizontal direction relative to the moving direction of the glass strip. The tilting directions of the air outlets located on the upper and lower sides of the glass strip are opposite.

6. An online cleaning device for TFT glass ribbons according to any one of claims 1 to 5, characterized in that, The cleaning solution is water.

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