JP2003291211A - Embossing apparatus and its product - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an embossing apparatus which has a low cost, high reliabil ity and productivity by improving a rotary hot pressing technique and to provide its product. <P>SOLUTION: The embossing apparatus heats to work the surface of a resin plate 5 via a stamper 1 by heater rollers 2, then continuously cools the plate to a glass transition temperature or lower, and then separates the stamper from the plate 5 via peeling rollers 3. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light guide plate used for a back irradiation device of a liquid crystal display device, a diffraction grating for optical multiplex communication, and a micro-panel by subjecting a resin plate that can be mass-produced to a surface treatment according to the application. Chemistry blood analyzer, CD
The present invention relates to processing of resin parts such as discs and record boards, which have been produced mainly by injection molding in the past, and which have a simple flat appearance and exert a function by a concavo-convex pattern shape according to the purpose of the surface.

[0002]

2. Description of the Related Art A so-called edge light system in which light is incident from a side surface (light incident surface) of a transparent plate which is a quadrangular plate, and the incident light is uniformly emitted from a surface (light emission surface). Is used in a back lighting device such as a liquid crystal display device. In such a back lighting device, a tubular light source is arranged on at least one side surface of the light guide plate, and an angle or a direction of light passing through the light guide plate is guided to a surface (light reflecting surface) facing a light emitting surface for emitting light. The surface unevenness pattern for changing the angle of the light reflected by the light plate is provided.

In recent years, the light guide plate is mainly manufactured by injection molding, but the basic shape is a simple flat plate. An extremely large injection molding machine will be required in the future to increase the size to 20 inches or more, and a new manufacturing method is required.

On the other hand, as a method for embossing a hard resin, so-called hot pressing has been used, but since it is a batch process, it has low productivity, and unless it is processed in a vacuum, air cannot escape and air bubbles are trapped. There was a problem of being lost.

Then, as a new manufacturing method, Japanese Patent Laid-Open No. -20
As disclosed in Japanese Unexamined Patent Publication No. 00-167926, a method has been proposed in which heat transfer is performed by a heat roller, and after allowing to cool sufficiently, the stamper is removed from the resin. Certainly, there is no bubble entrapment, but in such a manufacturing method, the resin plate is warped and deformed by thermal stress, so its application is limited to flexible materials and not suitable for rigid flat plates. There was a problem that was extremely low.

[0006]

SUMMARY OF THE INVENTION The present invention is intended to solve the above-mentioned problems of the prior art and to provide an embossing apparatus which is inexpensive, has high reliability and high productivity, and a product thereof.

[0007]

In order to solve the above-mentioned problems, the invention of claim 1 of the present application follows the rotation of the heater roller after pressing a stamper having an embossed pattern by a heater roller rotating under temperature control on a resin plate. The present invention is characterized in that the stamper and the resin plate are moved in contact with each other, and then the stamper is continuously separated from the resin plate by the peeling roller.

The invention according to claim 2 of the present application is characterized in that the distance between the peeling roller and the heater roller can be changed and the progress of cooling can be controlled.

The invention according to claim 3 of the present application is characterized in that the stamper is in the form of an endless belt, which enables continuous processing in which the stamper is loaded on the left side of the roller conveyor one after another and discharged on the right side of the roller conveyor one after another. To do.

According to a fourth aspect of the present invention, the stamper and the heater roller are provided on both sides of the resin plate, and both sides are processed simultaneously.

According to a fifth aspect of the present invention, a cartridge for accommodating a flat resin plate is provided on the non-embossed surface of the resin plate to position the resin plate, support reaction force during embossing, It is characterized by carrying.

The invention according to claim 6 of the present invention is characterized in that the heating temperature of the cartridge is controlled to prevent warping of the resin plate due to uneven heat.

The invention of claim 7 of the present invention is characterized in that the non-embossed surface of the resin plate is provided with an opposed roller which is heated and temperature-controlled to prevent the resin plate from warping due to uneven heat. . The invention of claim 8 of the present invention is characterized in that the embossing is performed while the resin plate is conveyed vertically in order to improve the temperature uniformity of the front and back surfaces.

[0014]

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described in detail below with reference to the drawings. First, the configuration of an embodiment of the embossing apparatus of the present invention will be described with reference to FIGS. 1 to 6. Figure 1
FIG. 3 is a schematic diagram showing a configuration of a side section of an embossing apparatus according to an embodiment of the present invention. FIG. 2 is a schematic diagram showing details of the II portion of FIG. FIG. 3 is a schematic diagram showing the configuration of another embodiment of the embossing device of the present invention. Figure 4,
5 and 6 are schematic views showing still another embodiment of the embossing apparatus of the present invention. FIG. 7 is a schematic diagram showing another embodiment as seen from the plate thickness cross section in the case of vertical conveyance.

In the figure, 1 is a stamper, 2 is a heater roller,
3 is a peeling roller, 4 is a tension roller, 5 is a resin plate, 6 is a facing roller, 7 is a rope, 8 is a cartridge,
Reference numeral 9 is a contact roller.

Generally, the stamper 1 has a thickness of about 0.1 to 0.5 mm, and in most cases, nickel is electroformed on the surface of a glass master having a required pattern formed by a photoresist technique. It is made. The stamper 1 is loaded with an appropriate tension and runs in close contact with the heater roller 2. The heater roller 2 has an electric heater, a thermocouple, and the like built therein, and is controlled so that the surface of the heater roller 2 reaches a predetermined temperature.

As shown in FIG. 1, a stamper 1 is formed into an endless hoop shape by welding several sheets, and rolls around the heater roller 2, the tension roller 4, and the peeling roller 2. Tension roller 4 on stamper 1
With this, an appropriate tension is applied to prevent meandering and breaking. The heater roller 2 and the tension roller 4 are peeled off, and the peeling roller 2 has a frame structure so that it can be lifted and lowered while maintaining the geometrical shape of the processed portion.

As a special modification, if the stamper 1 on one side is a hoop with a mirror surface, it is possible to emboss only one surface.

The distance between the upper and lower heater rollers 2 is controlled so as to absorb errors such as the plate thickness and roller eccentricity under a constant pressure of load control which is similar to the plate thickness of the resin plate 5 at the time of processing. The position is preferably controlled so that the gap becomes slightly smaller. In this way, the stamper is pressed against the resin plate 5 with a constant pressure, so that the deviation in the thickness of the resin plate 5 and the mechanical dimension error are absorbed, and the transfer failure is prevented.

Due to the nature of the structure, the dimensional accuracy at room temperature cannot always be maintained at high temperature. Therefore, in the final finish grinding of the heater roller 2 and the facing roller 6, the circularity, parallelism, and cylindricity can be ensured with higher accuracy if the heating roller 2 and the opposing roller 6 are processed while being heated to the operating temperature.

As shown in FIG. 1, between the upper and lower roller units, there is provided a roller conveyor that conveys the resin plate 5 from left to right as indicated by solid arrows.

The distance L between the heater roller 2 and the peeling roller 2
Is configured to be adjustable. That is, in the processing method of the present patent, the thickness of the resin plate 5 is mostly between 1 mm and 10 mm, while the embossing unevenness depth is 0.1 m.
Most are m or less. Therefore, it is sufficient that the heating depth during processing is in the range of 0.1 mm or less and above the glass transition temperature. That is, as shown in FIG. 2, the resin plate 5 is immediately under the heater roller 2, only the surface layer portion is rapidly heated to the glass transition temperature or higher by the stamper 1 to be softened, and is pressed and plastically deformed, and then conveyed while being in contact with the stamper 1. To be done. At this time, the resin plate 5 is cooled while cooling the surface of the stamper 1 to the outside air.
Due to the heat transfer to itself, the vicinity of the surface of the resin plate 5 is cooled and solidified with a gentle temperature distribution.

Here, if the stamper 1 is separated from the resin plate 5 at a position where the temperature is below the glass transition temperature and solidifies, the shape is not disturbed and good transfer is achieved. This is because the stamper 1 is a metal mainly composed of nickel and its coefficient of thermal expansion is much smaller than that of resin. Furthermore, the resin plate 5 heats only its surface layer during processing and the average temperature of the entire plate thickness. Is almost unchanged. The heating temperature and pressure of the heater roller 2 are determined and the distance L is determined by the properties of the resin, the depth of embossing, and the characteristics of the shape.

As an example, when processing a prism type light guide plate with an emboss depth of 25 μm on an acrylic plate having a glass transition temperature of 120 ° C., the heater roller temperature is 180 ° C. and the pressing force is 4 kg.
/ Mm, speed 600 mm / min, L = 100 mm, and good transfer with a transfer depth of almost 100% was obtained.

It is preferable that the temperature of the resin plate 5 before processing is constant in order to stabilize the operation, and it is preferable that the resin plate 5 is heated and maintained at a constant temperature in order to improve productivity.

When the embossed pattern has a sharp cross-sectional shape and is hard to peel off and a minute portion of the resin sticks to the stamper 1, the stamper 1 or the resin plate 5 is sprayed with a demolded or the resin plate 5 is used as a component. It is better to include a release agent.

Another factor that determines the distance L is the warp of the resin plate 5 after processing. Since the processing method is local heating of the plate surface, in order to prevent the resin plate 5 from warping after cooling, the heating temperature of the heater roller 2 and the distance L to the peeling roller 3 are also one of the parameters for plate warpage control. . The temperature of the peeling roller 3 may be one of the control items.

FIG. 3 shows an example of a reversible type in which the production amount is small. The stamper 1 is connected to the belt 7 at both ends thereof and is provided with a tension applying device (not shown). Although the heater roller 2 is a cylinder in the figure, it may be a partial circle such as a fan when the embossing depth is deep, the radius is large, and the required development length is one rotation or less.

FIG. 4 shows an example in which the back surface of the resin plate 5 is used for positioning and mounting in the cartridge 8, and the progress of the cartridge 8 is controlled so that the embossed pattern of the stamper 1 is imprinted at the correct position on the resin plate 5. It

The cartridge 8 also has a heater for preventing the warp and it is preferable to control the temperature. However, when the warp of the resin plate 5 is corrected in the post-treatment, the heater is attached to the cartridge 8. Is unnecessary.

In FIG. 5, the rear surface of the resin plate 5 is mirror-finished to form a counter roller 6 whose heating temperature is controlled. The counter roller 6 supports reaction force during embossing, rotational conveyance,
It has the function of heating to prevent warpage. It should be noted that the back surface can be embossed, but it is separated while it is hot, and the pattern becomes shallower.

FIG. 6 shows an embodiment in which the rigidity of the stamper 1 is sufficiently high so that the stamper 1 and the cartridge 8 are fastened at their rear end portions so as not to be affected by thermal strain, and the contact roller is advanced in accordance with the progress of processing. The peeling roller 9 continuously peels off the stamper 1 from the resin plate 5, and the distance L is also variable here. The contact roller 9 is required to have heat resistance without damaging the embossed pattern of the stamper 1, and therefore its surface is preferably made of fluororubber or silicon rubber.

Here, the loading and discharging of the resin plate 5 are both on the right side after advancing in the direction of the arrow. The cartridge 8 on which the unprocessed resin plate 5 is placed retreats in the direction of the dashed arrow,
At this time, the heater roller 2 is raised and is not processed when retracted, and the stamper 1 is merely put on the resin plate 5 lightly. According to this figure, the productivity is the lowest, but the equipment is also the cheapest.

FIG. 7 shows a resin plate 5 in the same equipment as in FIG.
It is a schematic diagram at the time of making the conveyance of the perpendicular | vertical. Here, the roller conveyor is provided with V-grooves at the necessary portions so that the resin plate 5 does not drop during transportation. In this way, it is possible to prevent heat from being accumulated on the lower surface side.
When the resin plate 5 is housed in the cartridge 8 as shown in FIGS. 4 and 6, it suffices to simply attach a vacuum suction device to the cartridge 8 so that the resin plate 5 is adsorbed to the cartridge 8.

[0035]

According to the present invention, it is possible to provide an embossing device and its product which are inexpensive, have high reliability and productivity, and have no plate warp, by a simple device.

[Brief description of drawings]

FIG. 1 is a schematic view showing a configuration of a side section of an embodiment of an embossing device according to the present invention.

FIG. 2 is a schematic view showing details of a II portion in FIG.

FIG. 3 is a schematic diagram showing the configuration of another embodiment of the embossing device of the present invention.

FIG. 4 is a schematic view showing still another embodiment of the embossing device of the present invention.

FIG. 5 is a schematic view showing another embodiment of the embossing device of the present invention.

FIG. 6 is a schematic view showing another embodiment of the embossing device of the present invention.

FIG. 7 is a schematic view showing another embodiment as seen from the plate thickness cross section in the case of vertical conveyance.

[Explanation of symbols]

1 ... Stamper, 2 ... Heater roller, 3 ... Peeling roller, 4 ... Tension roller, 5 ... Resin plate, 6 ... Opposing roller, 7 ... Rope, 8 ... Cartridge, 9 ... Contact roller

Claims (8)

[Claims] 1. A stamper having an embossing pattern applied by a heater roller rotating under temperature control is heated and pressed on a resin plate, and then the stamper and the resin plate are moved in contact with each other according to the rotation of the heater roller, and then the stamper is peeled off by a peel roller. An embossing device and its product, which continuously separates from a resin plate. 2. The embossing apparatus and its product according to claim 1, wherein the distance between the peeling roller and the heater roller is changeable. 3. The embossing apparatus and the product thereof according to claim 1, wherein the stamper has an endless belt shape. 4. The embossing apparatus and its product according to claim 1, wherein the stamper and the heater roller are provided on both sides of the resin plate and both sides are processed simultaneously. 5. A cartridge for accommodating a flat resin plate is provided on a non-embossed surface of the resin plate to support reaction force during embossing and convey the resin plate.
The embossing device and its product according to the item. 6. The embossing apparatus and its product according to claim 5, wherein the cartridge is heated and the temperature is controlled to prevent the resin plate from warping due to uneven heat. 7. A non-embossed surface of the resin plate is provided with a heated and temperature-controlled counter roller to support reaction force during embossing, convey the resin plate, and prevent warping of the resin plate due to uneven heat. The embossing device and the product thereof according to claim 1, characterized in that. 8. The embossing apparatus and the product thereof according to any one of claims 1 to 7, wherein the embossing is performed while the resin plate is conveyed vertically.