TW201424984A - Optical plate molding device and optical plate molding method - Google Patents

Abstract

An optical plate molding device and an optical plate molding method are provided. The molding device comprises a die head that can extrude a molten resin raw material, first and second rollers disposed at a downstream of the die head, and a magnetic field generating unit disposed at one side of the second roller. The resin raw material can be guided to enter a gap between the first and second rollers, and the second roller has an initial roll section in contact with the resin raw material. The magnetic field generating unit can generate a magnetic field so as to heat up the initial roll section. The increase of the temperature of a portion of the second roller through the inductive electric power of the magnetic field generated by the generating unit permits a high-temperature transcription and a low-temperature stripping of the resin raw material. The present invention has low equipment and operation costs and facilitates the temperature control.

Description

Optical plate forming device and optical plate forming method

The present invention relates to a molding apparatus for an optical sheet and a molding method thereof, and more particularly to a molding apparatus such as a diffusion plate, a light guide plate, or other optical sheets having different optical effects and having a microstructure on the surface, and a molding method thereof.

Referring to Fig. 1, there is shown a roller device for forming a microstructured optical plate 13, comprising a structural wheel 10 having a microstructure (not shown) on its surface, respectively disposed at an upstream position and a downstream position of the structural wheel 10. A first roller 11 and a second roller 12, and a thermocouple heating pad (not shown) located below the structural wheel 10 and capable of heating the structural wheel 10. When the microstructured optical plate 13 is fabricated, the molten optical sheet material is first injected through a rolling position 101 between the first roller 11 and the structural wheel 10, and the thermocouple heating sheet not shown heats the optical The raw material of the sheet is maintained in a softened state, so that the structural wheel 10 is rolled on the surface of the raw material of the optical sheet to form a corresponding microstructure, thereby forming the microstructured optical plate 13. The microstructured optical plate 13 continues to be driven by the rotating rollers and begins to disengage from the structural wheel 10 from a release position 102 between the structural wheel 10 and the second roller 12 and is continuously conveyed in a downstream direction.

However, since the heating sheet is heated by heating the entire optical sheet material, and first heating the unstructured contact surface 131 of the optical sheet material downward, a structural contact surface 132 located above by heat conduction is provided. When the temperature is raised, the structure of the overall heated optical sheet material is poorly transliterated, and the sheet warpage problem is liable to occur. In addition, in fact, the structure wheel 10 corresponds The temperature of the portion of the rolling position 101 needs to be high to facilitate microstructure transfer, and the temperature of the portion of the structural wheel 10 corresponding to the release position 102 must be low to facilitate peeling of the optical plate 13. However, since the structural wheel 10 is heated by the heating piece, the overall temperature is uniform. If the structural wheel 10 is low in temperature as a whole, the surface of the plate is not softened and the transfer rate is not good. Conversely, if the entire structural wheel 10 is at a relatively high temperature, the optical plate 13 is difficult to peel off.

In order to improve the above-mentioned lack, a roller device capable of multi-zone temperature control as shown in FIG. 2 has been developed, the improvement of which is mainly to replace the structural wheel 10 of FIG. 1 with a temperature-controlled wheel unit 14, which includes a surface. A main roller 141 having a microstructure (not shown) and being hollow, and four temperature-controlled wheels 142 mounted inside the main roller 141. The main roller 141 itself can be rotated, and a central shaft 140 of the main roller 141 can also drive the isothermal control wheel 142 to rotate synchronously. Since the temperature control wheels 142 are independently disposed and independently rotated, each of the temperature control wheels 142 can receive different heat sources, respectively, thereby generating different temperatures. Through the temperature control wheels 142, the temperature of different parts on the main roller 141 can be adjusted, so that the main roller 141 can achieve the effects of high temperature transfer and low temperature peeling.

However, due to the complicated structure of the temperature control wheel unit 14, the overall device cost is increased and the operation is complicated. Moreover, since the roller device of FIG. 1 has been widely used, if the temperature control wheel unit 14 of FIG. 2 is substituted for the structural wheel 10 of FIG. 1, the structural wheel 10 already installed in the device must be discarded, causing waste and Incur additional equipment costs. In addition, temperature control of each of the individual temperature-controlled wheels 142 also increases production costs and increases operational complexity, so the known roller device needs to be improved.

Accordingly, it is an object of the present invention to provide a molding apparatus which is low in cost, simple in temperature control, and which does not require modification of the optical sheet of the prior art.

Another object of the present invention is to provide a molding method for an optical sheet having a low manufacturing cost and a simple temperature control method.

Accordingly, the molding apparatus for an optical sheet of the present invention comprises: a die which can eject molten resin material, a first roller located downstream of the die, a second roller, and a magnetic field generating unit. The second roller is located downstream of the first roller and spaced apart from the first roller, the resin material can be led between the first roller and the second roller, and the second roller has a contact The initial rolling portion of the resin material. The magnetic field generating unit is disposed at one side of the second roller at intervals and located downstream of the initial rolling portion.

The forming method of the optical plate of the present invention is carried out in conjunction with a forming device of an optical plate, the forming device of the optical plate comprising: a first roller, and a second roller located downstream of the first roller, the optical plate The molding method comprises: injecting a molten resin material between the first roller and the second roller, the second roller has an initial rolling portion contacting the resin material; and providing a magnetic field generating unit to make the second roller The temperature of the initial rolling portion is from 80 ° C to 200 ° C, preferably from 90 ° C to 180 ° C, more preferably from 100 ° C to 160 ° C; and the resin material is separated from the second roller at a release position. The portion of the two rollers corresponding to the release position is a release portion, and the release portion The temperature of the bit is 40 ° C to 90 ° C and is less than the temperature of the initial rolling portion of the second roller. Preferably, the temperature of the release portion is from 50 ° C to 85 ° C, more preferably from 60 ° C to 80 ° C.

The effect of the invention is that by setting the magnetic field generating unit, the local temperature of the second roller is raised by the principle of magnetically generating electricity and generating heat, thereby achieving the purpose of high temperature transfer and low temperature peeling. Since the magnetic field generating unit can be compatible with the existing roller device, it is not necessary to change the original roller structure and the relative arrangement relationship in the design, thereby controlling the temperature distribution of each region in a simple manner. Therefore, the device of the present invention has lower cost, lower operating cost, and simple temperature control mode.

The above and other technical contents, features and advantages of the present invention will be apparent from the following detailed description of the preferred embodiments.

Referring to Figures 3 and 4, a preferred embodiment of the optical plate forming apparatus of the present invention is used for forming an optical plate 2 and can guide the optical plate 2 to be transported in a direction 3 toward a production line. The surface of the optical plate 2 can have a number A microstructure (not shown) such as a light guide plate or a light diffusing plate is not limited thereto. The forming device of the optical plate comprises: a die 51, a first roller 52, a second roller 53, a third roller 54, and a magnetic field generating unit 55.

The die 51 can eject a molten resin material 4 which is a resin having optical properties and can be formed into the optical plate 2, and the kind thereof is not limited, and specific examples thereof are (meth) acrylate-based resins. , polycarbonate resin (PC resin), styrene resin (PS resin), methyl methacrylate - Styrene copolymer (MS resin), acrylonitrile-styrene copolymer (AS resin), cyclic olefin polymer (COC resin), polyethylene terephthalate (PETG resin), and the like.

The above-mentioned (meth) acrylate-based resin means an acrylate-based resin and/or a methacrylate-based resin, and is a polymer formed of a (meth) acrylate-based monomer, for example, polymethyl methacrylate. Polymethyl methacerylate (PMMA), the above (meth) acrylate monomer, means acrylate monomer and / or methacrylate monomer, including methyl methacrylate, ethyl methacrylate A monomer such as isopropyl methacrylate, n-butyl acrylate, methyl acrylate, ethyl acrylate or isopropyl acrylate, wherein methyl methacrylate monomer and methyl acrylate monomer are preferred.

Various additives such as a light diffusing agent, a fluorescent agent, an ultraviolet absorber, an antioxidant, and the like can be added to the resin raw material 4. Specific examples of the light diffusing agent are inorganic fine particles and organic fine particles. The inorganic fine particles are, for example, fine particles such as barium sulfate (BaSO ₄ ) or titanium oxide (TiO ₂ ); and the organic fine particles are, for example, a polystyrene resin, a (meth)acrylic resin, or an organic germanium oxide resin fine particle.

The first roller 52 is located downstream of the die 51, and downstream or upstream as used herein refers to the relative upstream or downstream relationship between the components depending on the order of the forming steps of the optical plate 2. The first roller 52 extends in an axial direction and has a long column shape. The first roller 52 can be referred to as a mirror roller, and its surface is flat without any protruding microstructure.

The second roller 53 is located downstream of the first roller 52, and The first roller 52 is spaced apart, and the distance between the second roller 53 and the first roller 52 is not limited, and can be adjusted according to the thickness of the optical plate 2 to be formed. The second roller 53 is elongated and elongated in a long column shape, and includes an initial rolling portion 531 adjacent to the first roller 52, a spacing from the initial rolling portion 531, and a distance from the third roller 54. A profile portion 532, and a rolling zone 533 between the initial rolling portion 531 and the release portion 532 and contacting the resin material 4. The resin material 4 can be introduced between the first roller 52 and the second roller 53, and the portion of the first roller 52 that cooperates with the second roller 53 to start contacting the resin material 4 is the initial roller. The pressing portion 531, and after the resin material 4 contacts the initial rolling portion 531, is driven by the rotation of the second roller 53, and is attached to the surface of the rolling portion 533. In contrast, the portion of the second roller 53 that is spaced apart from the rolling zone 533 (i.e., the upper surface of the second roller 53 as shown in the drawing) is not in contact with the resin material 4.

It should be noted that, since the second roller 53 continuously rotates during use, the initial rolling portion 531, the release portion 532 and the rolling portion 533 do not refer to the three fixed portions on the second roller 53, but When the second roller 53 is rotated and used, the initial rolling portion 531 is located near the first roller 52, and the releasing portion 532 is located near the third roller 54. The rolling portion 533 is a portion between the pressing portion 531 and the releasing portion 532 and having the surface of the optical sheet 2 covered with the resin material 4 during the production of the optical sheet 2.

On the other hand, the second roller 53 has a plurality of transfer microstructures 534 located on the surface (and adjacently arranged along the length thereof), which can be used in the resin material 4 When the second roller 53 is between the first roller 52 and the first roller 52, the resin material 4 is rolled to form a surface microstructure corresponding to the transfer microstructure 534 on the surface of the resin material 4, so that the surface The optical plate 2 formed by the subsequent hardening of the resin material 4 has the microstructures not shown, and the microstructure of the optical plate 2 is not limited, and the cross section thereof may be a prism lens. A shape such as a lenticular lens. Preferably, the material of the second roller 53 is metal, so that an eddy current can be induced by the changing magnetic field to generate thermal energy.

The third roller 54 is located downstream of the second roller 53 and is disposed opposite to the second roller 53. The distance between the third roller 54 and the second roller 53 is not limited and may be adjusted depending on the thickness of the optical plate 2 to be formed. The third roller 54 has the same shape as the first roller 52, and is also a mirror roller having a flat surface and no protruding microstructure. After the resin material 4 passes through the rolling zone 533 of the second roller 53, it can be led into the second roller 53 and the third roller 54, and the resin material 4 is interposed between the second roller 53 and The release position 540 between the third rollers 54 is separated from the second roller 53 , and the portion of the second roller 53 corresponding to the release position 540 is the release portion 532 .

The magnetic field generating unit 55 is disposed at one side of the second roller 53 at intervals, and is located downstream of the initial rolling portion 531, and generates a magnetic field to raise the temperature of the initial rolling portion 531 of the second roller 53. Specifically, the magnetic field generating unit 55 of the present embodiment is a coil 551 located below the second roller 53, and is wound and extended along the longitudinal direction of the second roller 53. In addition, the magnetic field generating unit 55 may be a high frequency heating machine (or For high-frequency heating machines, high-frequency alternating current is called high-frequency, high-frequency heating, and heat is generated by the inside of the material to be heated. The principle is that the metal or conductor can be heated at high frequency by the principle of alternating electromagnetic induction heating. Therefore, the heating is rapid, and the temperature of the material to be heated is uniform inside and outside. The high frequency heating machine of the present invention has a frequency range of 100 KHz to 500 KHz and a power of 10 KW to 500 KW, such as Sumitomo High Frequency Heating Machine.

The magnetic field generating unit 55 is disposed on one side of the rolling zone 533 at intervals along the length direction of the second roller 53, that is, on the side of the second roller 53 that covers the portion of the resin material 4, so The resin material 4 is interposed between the second roller 53 and the magnetic field generating unit 55. From another point of view, the position of the magnetic field generating unit 55 can be correspondingly located between the initial rolling portion 531 to a portion where the initial rolling portion 531 extends a circumferential angle of 100 degrees toward the rotating direction of the second roller 53 (eg, The range between the two auxiliary lines 7 of Fig. 3) is preferably disposed between the portions of the circumferential angle of 80 degrees, more preferably between the portions of the circumferential angle of 45 degrees. The position limitation of the magnetic field generating unit 55 is mainly that the portion for limiting the temperature rise of the second roller 53 is not excessive, so as to prevent the heating time of the resin material 4 on the second roller 53 to be too long, because if the resin material 4 is heated for a long time. Too long to cause the entire sheet to be softened by heat, which will destroy the microstructure of the shaped sheet. On the other hand, the magnetic field generating unit 55 can raise the temperature of the second roller 53, but does not directly heat the resin material 4. The structural surface of the resin material 4 (i.e., the surface contacting the second roller 53) is heated by the second roller 53, and the other side of the resin material 4 opposite to the structural surface is not directly heated, so that it can also be avoided. The resin raw material 4 is excessively softened as a whole.

Referring to Figures 3, 4 and 5, a preferred embodiment of the method of forming an optical sheet of the present invention is carried out in conjunction with a forming apparatus for the optical sheet, comprising:

(1) Step 61: The molten resin material 4 is injected between the first roller 52 and the second roller 53, so that the initial rolling portion 531 of the second roller 53 comes into contact with the resin material 4. Here, the resin material 4 can be extruded by the die 51 of an extruding device (for example, an extruder). The first roller 52 and the second roller 53 rotate in opposite directions to jointly lead the resin material 4 to travel in the direction 3 toward the production line.

(2) Step 62: providing a magnetic field to raise the temperature of the initial rolling portion 531 of the second roller 53 to 80 ° C ~ 200 ° C, at this time the second roller 53 continues to roll the resin material 4, so directly The structural molding surface of the resin material 4 is heated, and the transfer microstructure 534 is rolled onto the resin material 4 to form a corresponding microstructure.

Specifically, in this step, the magnetic field generating unit 55 is disposed under the second roller 53 , and is mainly disposed at the initial rolling portion 531 of the second roller 53 to the initial rolling portion 531 toward the second The direction in which the roller 53 rotates is extended by a portion of the circumferential angle of 100 degrees, and a current is supplied to the magnetic field generating unit 55, and the magnetic field generating unit 55 can generate a varying magnetic field by changing the magnitude or direction of the current. Since the initial rolling portion 531 of the second roller 53 is close to the magnetic field generating unit 55, and the magnetic field generated by the magnetic field generating unit 55 is mainly concentrated in the initial rolling portion 531, the initial rolling portion of the second roller 53 The portion other than 531 is only subjected to a small magnetic field or hardly subjected to a magnetic field, so the initial rolling portion 531 is most strongly affected by the changing magnetic field, and because the second roller The material of 53 is metal, so that the initial rolling portion 531 generates an eddy current and raises the temperature under the varying magnetic field, so that the temperature is raised to 80 ° C to 200 ° C. In this temperature range, the resin material 4 attached to the second roller 53 is maintained in a proper softened state, and the transfer microstructure 534 of the second roller 53 is facilitated on the resin material 4. Rolling and transfer to form a microstructure.

It is to be noted that since the selection of the resin material type 4 is related to the type and function of the optical sheet 2 to be produced, the rolling transfer temperature which must be provided for the resin material 4 of different materials is slightly different, but the above is not taken off. The temperature range of 80 ° C ~ 200 ° C. Moreover, the winding density and current of the coil 551 affect the strength of the magnetic field, thereby affecting the magnitude of the eddy current generated by the metal and the temperature at which the metal rises. When the magnetic field is stronger, the larger the eddy current of the metal, the more significant the temperature rise effect. Therefore, the local temperature of the second roller 53 needs to be raised to several degrees, and can be controlled by changing the winding number or current intensity of the coil 551; if a high-frequency heating machine is used, it is controlled by changing the frequency of the alternating current. temperature.

(3) Step 63: The second roller 53 is continuously rotated, so that the resin material 4 is guided between the second roller 53 and the third roller 54, and is separated from the second roller at the release position 540. 53. In this embodiment, the second roller 53 and the third roller 54 rotate in opposite directions to jointly lead the resin material 4 to travel in the direction 3 toward the production line. The temperature of the release portion 532 is smaller than the temperature at which the initial rolling portion 531 of the second roller 53 is raised in the above step 62. Preferably, the temperature of the release portion 532 is 40 ° C to 90 ° C. The temperature of the release portion 532 is low, It is advantageous for the resin material 4 to cool and form the optical plate 2, and the resin material 4 can be smoothly separated from the second roller 53. Subsequent to the third roller 54 and other rollers not shown, the finished optical plate 2 continues to be transported downstream of the production line.

In addition, this step 62 is only for explaining the manner in which the magnetic field is generated by the magnetic field generating unit 55, instead of defining the sequence of operations for setting the magnetic field generating unit 55, since the optical sheet 2 is actually formed by the present invention. All of the components in the molding apparatus can be erected from the beginning, and the operation of molding the optical sheet 2 can be automatically performed as soon as the relevant components are activated.

In summary, by providing the magnetic field generating unit 55, the initial rolling portion 531 can generate an induced current in a changing magnetic field to be converted into heat energy, thereby increasing the temperature of the portion, and the releasing portion 532 is not subjected to By heating, the temperature of the release portion 532 is relatively low. Therefore, the present invention improves the local temperature of the second roller 53 by the principle of magnetically generating electricity and generating heat, thereby achieving the purpose of high temperature transfer and low temperature peeling. The present invention generates the local heating of the second roller 53 through the magnetic field generating unit 55. The magnetic field generating unit 55 can be compatible with the existing roller device, and the original roller structure and the relative arrangement relationship need not be changed in design. In this way, the purpose of controlling the temperature distribution of the individual zones is achieved in a simple manner. Therefore, the apparatus of the present invention has a low cost, a low operating cost for manufacturing the optical sheet 2, and a simple temperature control method, which contributes to industrial utilization.

However, the above is only the preferred embodiment of the present invention, and the scope of the present invention cannot be limited thereto, that is, the patent application according to the present invention The scope of the invention and the equivalent equivalents and modifications of the invention are still within the scope of the invention.

2‧‧‧Optical board

3‧‧‧Product line direction

4‧‧‧Resin raw materials

51‧‧‧Mold

52‧‧‧First wheel

53‧‧‧Second wheel

531‧‧‧Initial rolling parts

532‧‧‧away parts

533‧‧‧Rolling area

534‧‧‧Transfer microstructure

54‧‧‧third wheel

540‧‧‧Out of position

55‧‧‧Magnetic field generating unit

551‧‧‧ coil

61~63‧‧‧Steps

7‧‧‧Auxiliary line

1 is a schematic view of a known roller device; FIG. 2 is a schematic view of another known roller device; and FIG. 3 is a schematic view of a preferred embodiment of a molding device for an optical plate of the present invention for molding an optical plate. 4 is a perspective view of the preferred embodiment of the present invention; and FIG. 5 is a block flow diagram showing a preferred embodiment of a method for forming an optical plate of the present invention.

2‧‧‧Optical board

3‧‧‧Product line direction

4‧‧‧Resin raw materials

51‧‧‧Mold

52‧‧‧First wheel

53‧‧‧Second wheel

531‧‧‧Initial rolling parts

532‧‧‧away parts

533‧‧‧Rolling area

54‧‧‧third wheel

540‧‧‧Out of position

55‧‧‧Magnetic field generating unit

551‧‧‧ coil

7‧‧‧Auxiliary line

Claims (16)

An optical plate forming apparatus comprising: a die for extruding molten resin material; a first roller located downstream of the die; and a second roller located downstream of the first roller and associated with the first roller a roller is disposed at intervals, the resin material may be introduced between the first roller and the second roller, and the second roller has an initial rolling portion contacting the resin material; and a magnetic field generating unit spaced apart It is disposed on one side of the second roller and located downstream of the initial rolling portion. The molding apparatus for an optical plate according to claim 1, further comprising a third roller located downstream of the second roller and disposed opposite to the first roller, the resin material can be led into the first Between the two rollers and the third roller, and the resin material is separated from the second roller at a release position between the second roller and the third roller, and the second roller corresponds to the release position. The part is a release part. A molding apparatus for an optical sheet according to claim 1, wherein the second roller has a plurality of transfer microstructures located on the surface. The apparatus for forming an optical plate according to claim 2, wherein the position of the magnetic field generating unit is correspondingly located at the initial rolling portion of the second roller to the initial rolling portion toward the second roller. Between the parts extending 100 degrees of the circumferential angle. The molding apparatus of the optical sheet of claim 4, wherein the position of the magnetic field generating unit is correspondingly located at the second roller The initial rolling portion is between the portion where the initial rolling portion extends at a circumferential angle of 80 degrees toward the second roller rotating direction. The apparatus for molding an optical plate according to claim 5, wherein the position of the magnetic field generating unit is correspondingly located at the initial rolling portion of the second roller to the initial rolling portion toward the second roller. Extend between the 45 degree circumferential angles. The optical plate forming apparatus according to claim 4, wherein the second roller has a rolling zone between the initial rolling portion and the releasing portion and contacting the resin material, the magnetic field is generated The cells are spaced apart on the side of the rolling zone and the resin material. The optical plate forming apparatus according to claim 1, wherein the magnetic field generating unit is a high-frequency heating machine. The optical plate molding apparatus according to claim 8, wherein the high-frequency heating machine has a frequency range of 100 KHz to 500 KHz. A molding apparatus for an optical sheet according to claim 1, wherein the material of the second roller is metal. A forming method of an optical plate is carried out in conjunction with a forming device of an optical plate, the forming device of the optical plate comprising: a first roller, and a second roller located downstream of the first roller, the forming of the optical plate The method comprises: injecting a molten resin material between the first roller and the second roller, the second roller has an initial rolling portion contacting the resin material; and providing a magnetic field generating unit to make the second roller Initial rolling section The temperature of the bit is from 80 ° C to 200 ° C; and the resin material is separated from the second roller at a release position, and the portion of the second roller corresponding to the release position is a release portion, and the release portion is The temperature is from 40 ° C to 90 ° C and is less than the temperature of the initial rolling portion of the second roller. The method of forming an optical plate according to claim 11, wherein the first roller and the second roller rotate in opposite directions. The method of forming an optical plate according to claim 12, wherein the forming device of the optical plate further comprises a third roller located downstream of the second roller and disposed opposite the first roller, the resin The raw material can be led between the second roller and the third roller, and the release position is between the second roller and the third roller. The method of forming an optical sheet according to claim 11, wherein the magnetic field generating unit is a high-frequency heating machine. The method of forming an optical plate according to claim 11, wherein the magnetic field generating unit is correspondingly disposed at the initial rolling portion of the second roller to extend to the initial rolling portion toward the second roller rotating direction Between the parts of the 100 degree circumferential angle. The method of forming an optical sheet according to any one of claims 11 to 15, wherein the material of the second roller is metal.