CN101450530A - Hot rolling device and method for forming double-sided microstructure optical membrane - Google Patents

Abstract

A hot rolling device and a method for forming a double-sided microstructure optical film. The hot rolling device is used for forming a double-sided microstructure on a first surface and a second surface of an optical film and comprises a first roller, a second roller and a heating unit. The first roller has a first pattern. The second roller has a second pattern. The heating unit is used for heating the first roller and the second roller. When the first roller and the second roller roll, the optical film passes through the space between the first roller and the second roller. The first roller and the second roller are respectively contacted and pressed on the first surface and the second surface, so that the first surface forms a first pattern and the second surface forms a second pattern.

Description

Hot rolling device and method for forming double-sided microstructured optical film

technical field

The present invention relates to a thermal rolling device and a method for forming a double-sided microstructured optical film, and in particular to a thermal rolling device with process continuity and a method for forming a double-sided microstructured optical film .

Background technique

MEMS and microstructure film core products are widely used in electronic products, such as liquid crystal display devices or light guide plates or optical display films of mobile phones. Taking a thin film transistor (Thin Film Transistor, TFT) liquid crystal display device as an example, the light guide plate of the backlight module is used to guide light, so that the liquid crystal panel presents uniform brightness.

When light enters the light guide plate with a polished surface, the light travels back and forth in the light guide plate until the energy of the light is completely attenuated. In this case, light cannot be effectively guided by the light guide plate to the liquid crystal panel, resulting in uneven brightness of the liquid crystal panel. Therefore, in order to make the light guide plate have a better light guide effect, microstructures are usually formed on the light guide plate. Due to the characteristics of the microstructure, after the light enters the light guide plate with the microstructure, the light is refracted out of the light guide plate. In this way, the light can be guided to the liquid crystal panel, so that the liquid crystal panel presents uniform brightness. Among them, the light guide plate with double-sided microstructure has a better light guiding effect than the light guide plate with single-sided microstructure. Therefore, the industry is committed to increasing the production capacity of light guide plates with double-sided microstructures to meet market demands.

In addition, since the thickness of the light guide plate will affect the size of the liquid crystal display device, in order to make the liquid crystal display device lighter and thinner, the industry is committed to reducing the thickness of the light guide plate.

Contents of the invention

In view of this, the object of the present invention is to provide a hot rolling device and a method for forming a double-sided microstructured optical film, which is to pass the optical film through a heated first roller with a first pattern and a second roller with a second pattern. Between the second rollers of the pattern, the first roller and the second roller press-bond the first pattern and the second pattern to the first surface and the second surface of the optical film. Compared with the light guide plate with single-sided microstructure, the light guide plate with double-sided microstructure of the present invention has better light guiding effect. The production capacity of the light guide plate with double-sided microstructure can be improved. Reduce the thickness of the light guide plate.

The present invention provides a thermal rolling device for forming a double-sided microstructure on a first surface and a second surface of an optical film, wherein the thermal rolling device comprises:

a first roller with a first pattern;

a second roller having a second pattern; and

a heating unit for heating the first roller and the second roller, when the first roller and the second roller roll, the optical film passes between the first roller and the second roller, and the second roller A roller and the second roller are in contact with and pressed against the first surface and the second surface respectively, so that the first pattern is formed on the first surface and the second pattern is formed on the second surface.

Wherein the heating unit heats the temperature of the first roller and the second roller to 50°C-200°C.

Wherein the rolling speed of the first roller and the second roller is 1m/min˜50m/min.

Wherein the first roller has a first end and a second end, the first end is opposite to the second end, the second roller has a third end and a fourth end, the third end is opposite to The fourth end has a first distance between the first end and the third end, and a second distance between the second end and the fourth end, and the hot rolling device further includes:

A thickness adjusting unit is used for adjusting the first distance and the second distance.

Wherein the thickness adjustment unit adjusts the first distance to be different from the second distance.

Wherein the optical film is located on a plane, the hot rolling device also includes:

a pair of alignment detection units, used to detect whether the first pattern and the second pattern formed on the optical film are aligned with each other; and

A control unit is used for controlling the displacement of the first roller and the second roller on the plane according to the detection result of the alignment detection unit.

It also includes:

A pressure detection unit is used to detect the pressure on the optical film when the optical film passes through the rolling first roller and the second roller.

It also includes:

A tension detection unit is used to detect the tension of the optical film.

It also includes:

A preheating unit is used for preheating the optical film before passing through the first roller and the second roller.

Wherein the preheating unit substantially heats the temperature of the optical film to 80°C-180°C.

It also includes:

A cooling unit is used for cooling the optical film after passing through the first roller and the second roller.

Wherein the cooling unit cools the temperature of the optical film to -50°C to 20°C.

Wherein the first roller and the second roller are made of metal.

Wherein the optical film is made of thermoplastic material.

Wherein the optical film is polycarbonate, polymethyl methacrylate or polyethylene terephthalate.

The invention provides a method for forming a double-sided microstructured optical film, which is characterized in that it comprises:

(a) providing a first roller having a first pattern and a second roller having a second pattern;

(b) heating the first drum and the second drum; and

(c) An optical film is passed between the rolling first roller and the second roller, and the first roller and the second roller are respectively in contact with and pressed against a first surface and a first surface of the optical film. Two surfaces, the first surface forms the first pattern and the second surface forms the second pattern.

Wherein the step (b) is to heat the temperature of the first roller and the second roller to 50°C-200°C.

Wherein the step (c) is rolling the first roller and the second roller at a speed of 1 m/min˜50 m/min.

Wherein the first roller has a first end and a second end, the first end is opposite to the second end, the second roller has a third end and a fourth end, the third end is opposite to For the fourth end, there is a first distance between the first end and the third end, and there is a second distance between the second end and the fourth end, and the forming method further includes:

(d) adjusting the first distance and the second distance.

Wherein the step (d) comprises:

(d1) adjusting the first pitch to be different from the second pitch.

Wherein the optical film is located on a plane, the forming method also includes:

(e) detecting whether the first pattern and the second pattern formed on the optical film are aligned with each other; and

(f) controlling the displacement of the first roller and the second roller on the plane.

It also includes:

(g) Detecting the pressure on the optical film when the optical film passes through the rolling first roller and the second roller.

It also includes:

(h) Detecting the tension of the optical film.

Wherein it also includes before the step (c):

(1) Preheating the optical film.

Wherein the step (I) is to preheat the temperature of the optical film to 80°C-180°C.

Wherein after the step (c) also includes:

(j) cooling the optical film.

Wherein the step (j) is to cool the temperature of the optical film to -50°C to 20°C.

Wherein in the step (a), the first roller and the second roller are made of metal.

Description of drawings

In order to make the above-mentioned content of the present invention more obvious and understandable, a preferred embodiment is specifically cited below, together with the accompanying drawings, and described in detail as follows, wherein:

FIG. 1 is a schematic diagram of a hot rolling device according to a preferred embodiment of the present invention.

FIG. 2 is an enlarged view of the first roller, the second roller and the optical film in FIG. 1 .

Fig. 3 is a cross-sectional view along 1A-1A' of Fig. 2 .

FIG. 4 is a schematic diagram showing unequal distances between the first roller and the second roller.

FIG. 5 is a flowchart of a method for forming a double-sided microstructured optical film.

Detailed ways

Please refer to FIG. 1 and FIG. 2 at the same time. FIG. 1 shows a schematic diagram of a hot rolling device 100 according to a preferred embodiment of the present invention. FIG. 2 shows the first roller 120, the second roller 130 and the optical An enlarged view of diaphragm 110 . For clarity, FIGS. 1 and 2 draw the double-sided microstructures on the optical film 110 with solid lines. As shown in FIG. 1 , the thermal rolling device 100 is used to form double-sided microstructures on a first surface 111 and a second surface 112 of an optical film 110 . The hot rolling device 100 includes a first roller 120 , a second roller 130 and a heating unit 140 . The first roller 120 has a first pattern 121 and the second roller 130 has a second pattern 131 . The first pattern 121 and the second pattern 131 are, for example, one-dimensional or two-dimensional optical microstructure patterns. The heating unit 140 is used to heat the first roller 120 and the second roller 130 , for example, the heating unit 140 heats the first roller 120 and the second roller 130 with a thermocouple or thermal kerosene.

As shown in FIG. 2 , when the first roller 120 and the second roller 130 roll simultaneously, the optical film 110 located on the XY plane passes between the first roller 120 and the second roller 130 along the X direction, and the first roller 120 and the second roller 130 contact and press the first surface 111 and the second surface 112 respectively. The heated first roller 120 and second roller 130 make the instantaneous temperature of the pressed first surface 111 and second surface 112 substantially reach the Tg point, so the first pattern 121 can be transferred to the first surface 111 and the The second pattern 131 is transferred to the second surface 112 .

Tg (Glass transition temperature) point is the glass transition temperature. When the polymer is heated from low temperature to Tg, it will change from a glass-like hard and brittle property to a rubbery state at a higher temperature. Therefore, when the temperature of the first surface 111 and the second surface 112 of the optical film 110 rises to Tg point, the first pattern 121 and the second pattern 131 can be transferred to the first surface 111 and the second surface 112 .

The thermal rolling device 100 disclosed in the preferred embodiment of the present invention can simultaneously form microstructures on both sides of the optical film 110 , thereby greatly improving production efficiency. In addition, the thermal rolling device 100 has process continuity. After the large-area optical film 110 passes through the rolling first roller 120 and the second roller 130, the optical film 110 with double-sided microstructure is cut according to the requirements. Cut into different sizes. In this way, the purpose of mass production can be achieved and the production time can be reduced.

The optical film 110 forming the first pattern 121 and the second pattern 131 is, for example, a backlight plate, an anti-reflection film, a light guide plate, etc., and can be applied to optoelectronic, optical, and consumer industries. In this embodiment, the optical film 110 is, for example, polycarbonate (PC), polymethylmethacrylate (PMMA) or polyethylene terephthalate (PET). However, the optical film 110 can also be other thermoplastic materials. In addition, the first roller 120 and the second roller 130 are preferably made of metal to have a better heat conduction effect.

Moreover, the heating unit substantially heats the temperature of the first roller 120 and the second roller 130 to 50° C. to 200° C., so that the first roller 120 and the second roller 130 can press the first surface 111 and the second surface 112 together. Instantly, the optical film 110 reaches the Tg point. In addition, the rolling speed of the first roller 120 and the second roller 130 is substantially 1 m/min˜50 m/min, so that when the first roller 120 and the second roller 130 contact the optical film 110, they reach the Tg point of the optical film. The contact time of the first roller 120 and the second roller 130 between the first roller 110 and the second roller 130 is just enough to transfer the first pattern 121 and the second pattern 131 to the first surface 111 and the second surface 112 .

Due to the optical characteristics of the optical film 110 , the first pattern 121 and the second pattern 131 formed on the optical film 110 need to be aligned with each other. Therefore, as shown in FIG. 1 , the hot rolling device 100 has a position detection unit 142 and a control unit 144 . The alignment detection unit 142 is used to detect whether the first pattern 121 and the second pattern 131 formed on the optical film 110 are aligned with each other. The criterion for judging the alignment is, for example, detecting whether the center point of the first pattern 121 on the optical film 110 is aligned with the center point of the second pattern 131 . The alignment detection unit 142 is, for example, a CCD visual detection to detect the first pattern 121 and the second pattern 131 on the optical film 110 .

The control unit 144 is used for controlling the displacement of the first roller 120 and the second roller 130 on the XY plane according to the detection result of the alignment detection unit 142 . For example, the control unit 144 controls the displacement of the second roller 130 on the XY plane by using an XY piezoelectric stage or a precision lead screw and a motor at both ends of the second roller 130 .

In addition, the thermal rolling device 100 has a thickness adjustment unit 146 for adjusting the distance between the first roller 120 and the second roller 130 perpendicular to the XY plane. Please refer to FIG. 3 , which shows a cross-sectional view along 1A-1A' of FIG. 2 . The first roller 120 has a first end 122 and a second end 123 , and the first end 122 is opposite to the second end 123 . The second roller 130 has a third end 132 and a fourth end 133 , and the third end 132 is opposite to the fourth end 133 . There is a first distance t1 between the first end 122 and the third end 132 , and there is a second distance t2 between the third end 123 and the fourth end 133 . The thickness adjusting unit 146 is used to adjust the first distance t1 and the second distance t2, so that parallel optical films 110 with different thicknesses can be obtained according to requirements.

In addition, since the first roller 120 and the second roller 130 are pressed on the optical film 110 at the same time, adjusting the first distance t1 and the second distance t2 to a very small distance will not affect the effect of forming double-sided microstructures. In this way, the first distance t1 and the second distance t2 can be adjusted to obtain an extremely thin optical film 110 , for example, a parallel optical film of about 0.3 mm. This kind of parallel optical film with a thickness of about 0.3 mm can be used as a light guide plate of a liquid crystal display device, so the size of the liquid crystal display device can be greatly reduced.

In addition, please refer to FIG. 4 , which shows a schematic diagram of the first roller 120 and the second roller 130 having unequal intervals. The thickness adjusting unit 146 can adjust the first distance t1 to be different from the second distance t2, so that the thickness of the optical film 110 corresponding to the first distance t1 is substantially different from the thickness of the optical film 110 corresponding to the second distance t2 . In this way, a wedge-shaped optical film 110 can be obtained, such as a wedge-shaped light guide plate.

Moreover, as shown in FIG. 1 , the hot rolling device 100 also includes a pressure detection unit 150 for measuring the force exerted on the optical film 110 when the optical film 110 passes through the rolling first roller 120 and the second roller 130 . pressure. The pressure detection unit 150 is, for example, rod-shaped and embedded in the first drum 120 and the second drum 130 . The pressure detection unit 150 can detect whether the optical film 110 is subjected to improper pressure, such as excessive, small or uneven pressure, and correct the first distance t1 and the second distance t2 accordingly.

Since the optical film 110 will produce an expansion effect after being heated, the thermal rolling device 100 preferably further includes a tension detection unit 152 for detecting the tension of the optical film 110, so that the tension of the optical film 110 is substantially reduced. Maintain a certain amount.

In addition, the hot rolling device 100 further includes a preheating unit 154 and a cooling unit 156 . The preheating unit 154 is used to preheat the optical film 110 before passing through the first roller 120 and the second roller 130, so that the first roller 120 and the second roller 130 press the first surface 111 and the second surface 112 instantly, The optical film 110 is easier to reach the Tg point. Furthermore, the preheating unit 154 preheats the optical film 110 so that the temperature of the optical film 110 can be raised steadily. In this way, the expansion result caused by the instantaneous temperature rise of the optical film 110 when the heated first roller 120 and the second roller 130 are pressed against the optical film 110 can be avoided. The preheating unit 154 preheats the optical film 110 by infrared rays or a hot air blower, for example. In this embodiment, the preheating unit 154 substantially heats the temperature of the optical film 110 to 80° C.˜180° C.

The cooling unit 156 is used for cooling the optical film 110 after passing through the first roller 120 and the second roller 130 , so that the first pattern 121 and the second pattern 131 can be quickly fixed on the first surface 111 and the second surface 112 . The cooling unit 156 is, for example, cooling the optical film 110 by cryogenic nitrogen. In this embodiment, the cooling unit 156 cools the temperature of the optical film 110 to -50°C˜20°C.

Please refer to FIG. 5 , which shows a flowchart of a method for forming a double-sided microstructured optical film, and please match the component numbers in FIGS. 1 to 4 at the same time. Firstly, step S510 is implemented to provide the first roller 120 with the first pattern 121 and the second roller 130 with the second pattern 131 .

Next, step S520 is implemented to adjust the first distance t1 and the second distance t2 .

Furthermore, step S530 is implemented to preheat the optical film 110 . In this embodiment, for example, the temperature of the optical film 110 is substantially preheated to 80° C.˜180° C.

Next, step S540 is implemented to heat the first roller 120 and the second roller 130 . In this embodiment, for example, the temperatures of the first drum 120 and the second drum 130 are substantially heated to 50° C.˜200° C.

Then, step S550 is implemented, the optical film 110 is passed between the rolling first roller 120 and the second roller 130, and the first roller 120 and the second roller 130 respectively contact and press-bond the first surface 111 of the optical film 110 And on the second surface 112 , the first pattern 121 is copied to the first surface 111 and the second pattern 131 is copied to the second surface 112 . In this embodiment, the first roller 120 and the second roller 130 roll at a speed of substantially 1 m/min˜50 m/min, for example.

Next, step S560 is implemented to cool the optical film 110 so that the first pattern 121 and the second pattern 131 are accelerated and fixed on the first surface 111 and the second surface 112 . In this embodiment, for example, the temperature of the optical film 110 is substantially cooled to -50° C.˜20° C.

The operating principle of the method for forming the double-sided microstructured optical film disclosed in the above embodiments of the present invention has been described in detail in the thermal rolling device 100 , so it will not be repeated here.

The above-mentioned hot rolling device and the method for forming the double-sided microstructure optical film according to the preferred embodiment of the present invention are to pass the optical film through the rolling first roller and the second roller after the first roller and the second roller are heated. between the rollers. When the first roller and the second roller press the first surface and the second surface of the optical film, the first pattern and the second pattern are copied to the first surface and the second surface respectively. In this way, double-sided microstructures can be formed on the optical film at the same time, so as to greatly improve production efficiency. In addition, it has at least the following advantages:

1. The hot rolling device of the present invention can form a large-area optical film into a double-sided microstructure, and cut it into different sizes according to requirements, so it has process continuity to mass produce and reduce production time.

2. By detecting whether the first pattern and the second pattern formed on the optical film are aligned with each other, and correcting the displacement of the first roller and the second roller accordingly, to improve the optical film with the first pattern and the second pattern yield rate.

3. The distance between the first roller and the second roller can be adjusted according to different requirements to obtain parallel optical films. In addition, the first distance and the second distance can be adjusted to different sizes to obtain a wedge-shaped optical film.

4. The distance between the first roller and the second roller can be adjusted to be extremely small, so that an extremely thin optical film can be obtained. Applying an extremely thin optical film to the light guide plate of the backlight module can greatly reduce the size of the liquid crystal display device.

5. Detect whether the optical film is subjected to improper pressure when it passes between the first roller and the second roller, so as to avoid excessive, small or uneven pressure on the optical film.

6. Detect the tension of the optical diaphragm and control the tension to maintain a certain value, so that the expansion effect of the optical diaphragm after heating will not affect the quality of the optical diaphragm.

7. Preheating the optical film before passing through the first roller and the second roller can make it easier for the optical film to reach the Tg point. In addition, the temperature of the optical film can be raised steadily, so as to avoid the expansion result caused by the instantaneous temperature rise of the optical film.

8. Cooling the optical film after passing through the first roller and the second roller can accelerate the setting of the first pattern and the second pattern on the first surface and the second surface of the optical film.

In summary, although the present invention has been disclosed as above with a preferred embodiment, it is not intended to limit the present invention. Those skilled in the art of the present invention can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention should be defined by the claims of the present invention.

Claims (28)

1. A thermal rolling device for forming a double-sided microstructure on a first surface and a second surface of an optical film, characterized in that the thermal rolling device comprises: a first roller with a first pattern; a second roller having a second pattern; and a heating unit for heating the first roller and the second roller, when the first roller and the second roller roll, the optical film passes between the first roller and the second roller, and the second roller A roller and the second roller are in contact with and pressed against the first surface and the second surface respectively, so that the first pattern is formed on the first surface and the second pattern is formed on the second surface. 2 . The hot rolling device according to claim 1 , wherein the heating unit heats the temperature of the first roller and the second roller to 50° C.˜200° C. 3 . 3 . The hot rolling device according to claim 1 , wherein the rolling speeds of the first roller and the second roller are 1 m/min˜50 m/min. 4 . 4. The hot rolling device as claimed in claim 1, wherein the first roller has a first end and a second end, the first end is opposite to the second end, and the second roller There is a third end and a fourth end, the third end is opposite to the fourth end, there is a first distance between the first end and the third end, the distance between the second end and the fourth end There is a second distance between them, and the hot rolling device also includes: A thickness adjusting unit is used for adjusting the first distance and the second distance. 5. The hot rolling device as claimed in claim 4, wherein the thickness adjustment unit adjusts the first distance to be different from the second distance. 6. The thermal rolling device according to claim 1, wherein the optical film is located on a plane, and the thermal rolling device further comprises: a pair of alignment detection units, used to detect whether the first pattern and the second pattern formed on the optical film are aligned with each other; and A control unit is used for controlling the displacement of the first roller and the second roller on the plane according to the detection result of the alignment detection unit. 7. The hot rolling device according to claim 1, further comprising: A pressure detection unit is used to detect the pressure on the optical film when the optical film passes through the rolling first roller and the second roller. 8. The hot rolling device according to claim 1, further comprising: A tension detection unit is used to detect the tension of the optical film. 9. The hot rolling device according to claim 1, further comprising: A preheating unit is used for preheating the optical film before passing through the first roller and the second roller. 10 . The hot rolling device according to claim 9 , wherein the preheating unit substantially heats the temperature of the optical film to 80° C.˜180° C. 11 . 11. The hot rolling device according to claim 1, further comprising: A cooling unit is used for cooling the optical film after passing through the first roller and the second roller. 12 . The hot rolling device according to claim 11 , wherein the cooling unit cools the temperature of the optical film to -50° C.˜20° C. 13 . 13. The hot rolling device as claimed in claim 1, wherein the first roller and the second roller are made of metal. 14. The thermal rolling device as claimed in claim 1, wherein the optical film is made of thermoplastic material. 15. The hot rolling device as claimed in claim 14, wherein the optical film is polycarbonate, polymethyl methacrylate or polyethylene terephthalate. 16. A method for forming a double-sided microstructured optical film, comprising: (a) providing a first roller having a first pattern and a second roller having a second pattern; (b) heating the first drum and the second drum; and (c) An optical film is passed between the rolling first roller and the second roller, and the first roller and the second roller are respectively in contact with and pressed against a first surface and a first surface of the optical film. Two surfaces, the first surface forms the first pattern and the second surface forms the second pattern. 17. The method for forming a double-sided microstructured optical film according to claim 16, wherein the step (b) is to heat the temperature of the first roller and the second roller to 50° C. to 200° C. . 18. The method for forming a double-sided microstructured optical film as claimed in claim 16, wherein the step (c) is to use the first roller and the second roller at a rate of 1 m/min to 50 m/min Speed scrolling. 19. The method for forming a double-sided microstructured optical film as claimed in claim 16, wherein the first roller has a first end and a second end, and the first end is opposite to the second end. end, the second roller has a third end and a fourth end, the third end is opposite to the fourth end, there is a first distance between the first end and the third end, the second end and there is a second distance between the fourth ends, the forming method further includes: (d) adjusting the first distance and the second distance. 20. The method for forming a double-sided microstructured optical film as claimed in claim 19, wherein the step (d) comprises: (d1) adjusting the first pitch to be different from the second pitch. 21. The forming method of the double-sided microstructured optical film as claimed in claim 16, wherein the optical film is located on a plane, and the forming method further comprises: (e) detecting whether the first pattern and the second pattern formed on the optical film are aligned with each other; and (f) controlling the displacement of the first roller and the second roller on the plane. 22. The method for forming a double-sided microstructured optical film as claimed in claim 16, further comprising: (g) Detecting the pressure on the optical film when the optical film passes through the rolling first roller and the second roller. 23. The method for forming a double-sided microstructured optical film as claimed in claim 16, further comprising: (h) Detecting the tension of the optical film. 24. The forming method of double-sided microstructured optical film as claimed in claim 16, wherein, before the step (c), it also includes: (1) Preheating the optical film. 25. The method for forming a double-sided microstructured optical film as claimed in claim 24, wherein the step (I) is to preheat the temperature of the optical film to 80°C-180°C. 26. The method for forming a double-sided microstructured optical film as claimed in claim 16, further comprising: (j) cooling the optical film. 27 . The method for forming a double-sided microstructured optical film as claimed in claim 26 , wherein the step (j) is to cool the optical film to -50° C. to 20° C. 27 . 28. The method for forming a double-sided microstructured optical film as claimed in claim 16, wherein in the step (a), the first roller and the second roller are made of metal.

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