CROSS-REFERENCE TO RELATED APPLICATION
This application claims the priority benefits of a Taiwan application serial no. 105109606, filed on Mar. 28, 2016. The entirety of the above-mentioned patent application is hereby incorporated by reference herein.
TECHNICAL FIELD
The present disclosure relates to a roll-to-roll apparatus.
BACKGROUND
When a glass is thinner, it is bendy to foil ii a flexible glass. The flexible glass has characteristics of being bent and high hardness. It is applicable to a plane substrate of an electronic paper (e-paper), a protective cover of a photovoltaic module, a substrate of a touch sensor, a solid-state light-emitting element, an electronic device and so on.
Currently, transferring the flexible glass is in a roll-to-roll manner. Although the flexible glass with thin thickness has a considerable degree of flexibility, it retains the brittle property. Stress concentration of the strength may occur in the flexible glass due to surface defects or scratches. Therefore, any unstable delivery, drag, and/or torsion of the flexible glass may cause a breakage of the flexible glass. The current roll-to-roll equipment can transfers the flexible glass via a roll-to-roll process. When the breakage of the flexible glass occurred, even the drive roller stops rotating, the flexible glass continues to produce more unpredictable damages because of its flexibility and inertia effect. Therefore, it is hard to identify the initial broken position and the broken causes, and fail to prevent breakages recurring in the future.
SUMMARY
In an embodiment of the present disclosure, a roll-to-roll apparatus may comprise an unwinding unit, a winding unit, at least one supporting unit, at least one breakage sensor, and at least one holding unit. The at least one supporting unit is disposed between the unwinding unit and the winding unit, and supports a flexible substrate to move from the unwinding unit to the winding unit. The at least one breakage sensor senses whether the flexible substrate is broken or not. The at least one holding unit grips the flexible substrate while a breakage of the flexible substrate is sensed by the at least one breakage sensor.
The foregoing will become better understood from a careful reading of a detailed description provided herein below with appropriate reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of a roll-to-roll apparatus according to an embodiment of the present disclosure.
FIG. 2A is a schematic view illustrating that the roll-to-roll apparatus of FIG. 1 has a breakage occurring in a flexible substrate.
FIG. 2B is an enlarged schematic view of a holding unit of FIG. 2A.
FIG. 3A is a schematic view illustrating that a holding unit of FIG. 1 grips the flexible substrate after the flexible substrate is broken.
FIG. 3B is an enlarged schematic view of the holding unit of FIG. 3A.
FIG. 4 is a schematic cross-sectional view of a holding unit of FIG. 1.
FIG. 5 is a schematic cross-sectional view of a holding unit of a roll-to-roll apparatus according to another embodiment of the present disclosure.
FIG. 6 is a schematic cross-sectional view of a holding unit of a roll-to-roll apparatus according to yet another embodiment of the present disclosure.
FIG. 7 is a partial schematic view of a roll-to-roll apparatus according to yet another embodiment of the present disclosure.
DETAILED DESCRIPTION
Below, exemplary embodiments will be described in detail with reference to accompanying drawings to be easily realized by a person having ordinary knowledge in the art. The inventive concept may be embodied in various forms without being limited to the exemplary embodiments set forth herein. Descriptions of well-known parts are omitted for clarity, and like reference numerals refer to like elements throughout.
FIG. 1 is a schematic view of a roll-to-roll apparatus according to an embodiment of the present disclosure. Referring to the embodiment of FIG. 1, a roll-to-roll apparatus 100 may comprise an unwinding unit 110, a winding unit 120, at least one supporting unit 130, at least one breakage sensor 140, and at least one holding unit 150. The supporting unit 130 is disposed between the unwinding unit 110 and the winding unit 120. A flexible substrate 50 is supported by the at least one supporting unit 130 to move from the unwinding unit 110 to the winding unit 120. The at least one breakage sensor 140 may sense whether the flexible substrate 50 is broken or not. The at least one holding unit 150 may grip the flexible substrate 50 while a breakage of the flexible substrate 50 is sensed by the at least one breakage sensor 140.
In the embodiment, the roll-to-roll apparatus 100 has the at least one a holding unit 150. Once a breakage of the flexible substrate 50 is sensed by the at least one breakage sensor 140, not only the unwinding unit 110 and the winding unit 120 stop unwinding and winding, but also the flexible substrate 50 may be stopped and gripped by the at least one holding unit 150. That may prevent the flexible substrate 50 from falling, swinging, and/or expansion of damages, so that related manufacturing processes resume easily. Original breaking states of the flexible substrate 50 can be held as much as possible, to find out the broken causes, and to prevent breakages occurring in the flexible substrate 50 again in the future.
Other technical features described below embodies selectively in the present disclosure, but the present disclosure is not limited thereto. The technical features of various embodiments described under the situation without conflict are applicable to other embodiments.
In the present embodiment, there are a plurality of supporting units 130, a plurality of breakage sensors 140 and a plurality of holding units 150. In other embodiments. one or more of the numbers of these elements in the foregoing may be one. The unwinding unit 110 and the winding unit 120 are rollers. For example, the rolled flexible substrate 50 is free from the unwinding unit 110 and received by the winding unit 120. The at least one supporting unit 130 is a roller, for example, the at least one supporting unit 130 may rotate synchronously with the movement of the flexible substrate 50 to avoid generating a relative displacement between the surface of the supporting unit 130 and the flexible substrate 50. Thereby, the supporting unit 130 may scratch the flexible substrate 50 as less as possible. In an embodiment, the at least one holding units 150 may correspond to the at least one supporting units 130, respectively, and the flexible substrate 50 is held by both the at least one holding unit 150 and the at least one supporting unit 130, but the present disclosure is not limited thereto.
In addition, the roll-to-roll apparatus 100 of this embodiment may further include a processing unit 160 to perform various processes on the flexible substrate 50. For instance, the processing unit160 may perform sputtering, evaporation, or other suitable processes on the flexible substrate 50. In the embodiment, an exemplary material of the flexible substrate 50 includes glass, but the material of the flexible substrate 50 may include other flexible continuous sheet materials, such as metal, plastic, paper like, and so on. The thickness of the flexible glass substrate may be less than 150 μm, such as 100 μm or less. The width of the flexible glass substrate 50 may be greater than or equal to 100 mm, such as more than 200 mm. The length of the flexible glass substrate 50 may be greater than or equal to 1 m, such as more than 10 m. However, the dimensions of the flexible glass substrate 50 are not limited thereto.
In the embodiment, each breakage sensor 140 may be a tension sensor. The at least one breakage sensor 140 may be disposed on the at least one supporting unit 130. A portion of the tension of the flexible substrate 50 may be applied on the at least one supporting unit 130, and the at least one breakage sensor 140 may calculate a tension of the flexible substrate 50 according to sensed components of the tension. During a normal operation, the tension of the flexible substrate 50 should be within a non ial range. Once the at least one breakage sensor 140 senses the tension is beyond the normal range, it may be determined that a breakage occurs in the flexible substrate 50.
After the at least one breakage sensor 140 determines that the breakage occurs in the flexible substrate 50, the at least one holding unit 150 starts to grip the flexible substrate 50. The time that the roll-to-roll apparatus 100 activates the at least one holding unit 150 to grip the flexible substrate 50 may be less than the time that the flexible substrate 50 falls, so as to facilitate the gripping efficiency achieving. The way to activate the holding unit 150 may include, for example, solenoid valves with air pressure driven, magnetism driven, or motor driven. In the high-speed solenoid valve case, the response time of activation may be less than 15 ms. The supporting unit 130 of the roll-to-roll apparatus 100 may be a roller, for example, a roller-type supporting unit having a diameter of six inches is used to convey the flexible substrate 50 (for example, an ultra-thin glass substrate). A circumferential angle 0 (labeled in FIG. 3B, also known as wrap angle) of a portion of the supporting unit 130 in contact with the flexible substrate 50 is generally in the range of 45° to 135°. The wrap angle of the supporting unit 130 in contact with the flexible substrate 50 is 45° is taken as an example. The length of the supporting unit 130 in contact with the flexible substrate 50 is 5.98 cm by calculation. The maximum possible conveying speed for the flexible substrate 50 is 5cm/sec, for example, it takes 1.197 seconds to make a move of 5.98 cm on the flexible substrate 50. While it takes 0.1055 seconds to make the move of 5.98 cm on the flexible substrate 50 with considering the gravity factor (with gravitational acceleration g of the movement). The response time of the solenoid valve is less than 15 ms, and it should be able to meet the requirement. Moreover, in order to prevent the flexible substrate 50 from suffering the damage caused by the holding unit 150, the range of the holding unit 150 in contact with the flexible substrate 50 may be in the range of the wrap angle of the supporting unit 130 with respect to the flexible substrate 50, that is, in the range of the supporting unit 130 in contact with the flexible substrate 50. Assume that a width of the flexible substrate 50 is L, the supporting unit 130 is a roller having a diameter is D, an area of the holding unit 150 in contact with the flexible substrate 50 is A, and the wrap angle is 45°, then A≦L×π×D/8. When the wrap angle is 135°, then A≦L×π×D×3/8.
FIG. 2A is a schematic view illustrating that the roll-to-roll apparatus of FIG. 1 has a breakage occurring in the flexible substrate. FIG. 2B is an enlarged schematic view of a holding unit of FIG. 2A. Referring to FIG. 2A, when the breakage just occurs in the flexible substrate 50, the state of each element of the roll-to-roll apparatus is substantially the same as the state under a normal operation. Referring to the embodiment of FIG. 2B, the holding unit 150 is arc-shaped. Under the normal operation, the holding unit 150 may not press onto the flexible substrate 50 and keep an appropriate distance D10 between the holding unit 150 and the flexible substrate 50. For example, the distance D10 is less than 100 μm. The less the distance D10 between the holding unit 150 and the flexible substrate 50 is, the much the shorten time required for gripping the breakage of the flexible substrate 50 is. If the distance D10 is too less, there may be possible risks that the flexible substrate 50 is scratched by the holding unit 150 under the normal operation. When a breakage occurs in the flexible substrate 50, the flexible substrate 50 closer to the winding unit 120 may tend to continue moving forward due to inertia, as shown by an arrow in FIG. 2A. Continued forward movement of the flexible substrate 50 may cause another breakage again because the flexible substrate 50 and the winding unit 120 may press each other. On the other hand, the flexible substrate 50 closer to the unwinding unit 110 may tend to spring-back due to counteraction or gravity, as shown by another arrow in FIG. 2A. Spring-back of the flexible substrate 50 may cause another breakage again because the flexible substrate 50 and the unwinding unit 110 press each other or the flexible substrate 50 loses the supporting of the tension, thereby swinging.
FIG. 3A is a schematic view illustrating that a holding unit of FIG. 1 grips the flexible substrate after the flexible substrate is broken. FIG. 3B is an enlarged schematic view of the holding unit of FIG. 3A. Referring to FIG.3A and FIG. 3B, when the breakage sensor 140 senses a breakage of the flexible substrate 50, it may drive the unwinding unit 110 and the winding unit 120 to stop unwinding and winding, respectively, and may drive the holding unit 150 to press onto the flexible substrate 50 on the supporting unit 130. Therefore, it may control the damage to occur in the initial region, to avoid the damage to spread through other regions of flexible substrate 50. It may keep the original state of the breakage, and help the cause analysis and resolve the issue of the breakage to avoid that the breakage occurs in the flexible substrate 50 again. In the embodiment, there may be a plurality of supporting units 150, and the breakage sensor140 may drive all of the plurality of supporting units 150 simultaneously for pressing onto the flexible substrate 50.
In calculating the force for stopping the flexible substrate 50 in time, there are some forces to be calculated when a breakage occurs in the flexible substrate 50. For example, a gravity and a mobile inertia force of the flexible substrate 50 between two adjacent supporting units 130 generated by the weight of the flexible substrate are considered. For instance, assume that a distance between two adjacent supporting units 130 is 1 m, a width and a thickness of the flexible substrate 50 made of glass are 350 mm and 100 μm, respectively. Unser this scenario, the weight of the flexible substrate 50 between two adjacent the supporting unit 130 is about 86.1 g. The holding unit 150 may provide a frictional force about 0.84378 Newton to stop the flexible substrate 50. In above embodiment, the motion force after the breakage occurs in the flexible substrate 50 is not take into consideration yet. A material of the holding unit 150 may be such as plastic, rubber, silicone, or other materials having a hardness less than the hardness of the flexible substrate 50. It may avoid the flexible substrate 50 is scratched during the holding process. Alternatively, the coefficient of sliding friction between the holding unit 150 and the flexible substrate 50 may further be considered.
FIG. 4 is a schematic cross-sectional view of a holding unit of FIG. 1. Referring to the embodiment of FIG. 4, the holding unit 150 may grip the boundary of the flexible substrate 50. The boundary of the flexible substrate 50 will not be used in the final product, and the holding unit 150 grips the boundary of the flexible substrate 50 may reduce the probability of damages for the quality of the final product.
FIG. 5 is a schematic cross-sectional view of a holding unit of a roll-to-roll apparatus according to another embodiment of the present disclosure. Referring to the embodiment of FIG. 5, two sides 132A of a supporting unit 132 may be higher than a middle portion 132B of the supporting unit 132. The boundary of the flexible substrate 50 may be in contact with the two sides 132A of the supporting unit 132. As described previously, the supporting unit 132 keeps in contact with the boundary of the flexible substrate 50 may reduce the probability of damages for the quality of the final product.
FIG. 6 is a schematic cross-sectional view of a holding unit of a roll-to-roll apparatus according to yet another embodiment of the present disclosure. Referring to the embodiment of FIG. 6, the holding unit 152 may be a roller, which may keep in contact with the flexible substrate 50 on the supporting unit 132. For instance, under the noiiiial operation, the supporting unit 132 in rotating may drive the flexible substrate 50 to move forward, and the frictional force between the flexible substrate 50 and the holding unit 152 may drive the holding unit 152 to rotate. Alternatively, the holding unit 152 may rotate independently to avoid generating the relative displacement between the surface of the holding unit 152 and the flexible substrate 50, thereby reducing the opportunity that the holding unit 152 scratches the flexible substrate 50. Once a breakage of the flexible substrate 50 is sensed by the breakage sensor 140, the at least one holding unit 152 is forced to stop rotating to apply a frictional force, thereby applying the brakes to stop the flexible substrate 50 in time. The holding unit 152 is in contact with the flexible substrate 50 on the supporting unit 132, which may shorten the time from the breakage occurs in the flexible substrate 50 to the flexible substrate 50 is stopped.
In addition, although the supporting unit 132 shown in FIG. 6 has a level difference, the supporting unit 130 without the level difference is applicable in the architecture of FIG. 6. In other words, the supporting unit 130 without the level difference may cooperate with the roller-type supporting unit 152 and keep in contact with the flexible substrate 50. This may shorten the time from the breakage occurs in the flexible substrate 50 to the flexible substrate 50 is stopped.
FIG. 7 is a partial schematic view of a roll-to-roll apparatus according to yet another embodiment of the present disclosure. In the embodiment, the at least one holding unit 154 may include a first holding portion 154A and a second holding portion 154B. While a breakage sensor 142 senses a breakage occurring in the flexible substrate 50, the at least one holding unit 154 grips the flexible substrate 50 and the flexible substrate 50 is kept between the first holding portion 154A and the second holding portion 154B. Moreover, the breakage sensor 142 may be such as an image sensor, and may determine whether the flexible substrate 50 is broken or not by capturing and automatically analyzing the images. In other embodiments, the breakage sensor 142 may be such as an optical sensor, and may detect the changes in the amount of light passing through the flexible substrate 50 or in the amount of the light reflected by the flexible substrate 50 to determine whether the flexible substrate 50 is broken or not.
While the breakage sensor senses a breakage occurring in the flexible substrate, the roll-to-roll apparatus according to an embodiment of the present disclosure may drive the holding unit to grip the flexible substrate to prevent the flexible substrate from continuously moving forward or shaking. Original breaking states of the flexible substrate can be held as much as possible and expanded damages can be prevented, which facilitates the cause analysis for improvement and reduces the difficulty of cleaning breakages.
It will be clear that various modifications and variations may be made to the disclosed methods and materials. It is intended that the specification and examples be considered as exemplary only, with a true scope of the disclosure being indicated by the following claims and their equivalents.
Patent Application
20170275120
