KR101751732B1 - Thermal transfer method for multiple curved surface - Google Patents

Abstract

According to an embodiment of the present invention, there is provided a method of manufacturing a multi-curved thermal transfer film, comprising the steps of: (a) (b) preparing a jig to be heated to a set temperature, and placing a window glass having multiple curved surfaces on the jig; (c) aligning the position of the multi-curvature thermal transfer film so as to face the window glass, and placing the multi-curvature thermal transfer film on an upper side of the window glass; And (d) compressing and thermally transferring the multi-curved thermal transfer film disposed on the window glass using a vertically moving pad.

Description

{THERMAL TRANSFER METHOD FOR MULTIPLE CURVED SURFACE}

An embodiment of the present invention relates to a multi-curved surface thermal transfer method.

In general, mobile phones are communication devices that are indispensable in modern society, and their functions are diversified beyond imagination. As the functions of the mobile phone become diversified, the IT technology accumulated in the mobile phone itself is complex, and accordingly, the product unit price is increasing.

Conventionally, display windows mounted on various mobile display devices including mobile phones are made of acrylic resin which is a synthetic resin material which is cheap and easy to manufacture. However, most synthetic resin is vulnerable to heat and scratches, the transmittance is worse than that of glass, and the consumption of battery is increased when the luminance is increased for a clear screen. In recent mobile display devices, glass (for example, tempered glass) .

On the other hand, an ink layer (i.e., an ink layer) is formed on the edge of the glass of the mobile display device by a thermal transfer method in order to realize appearance aesthetics and other functional effects.

In recent years, a stereoscopic glass having a 3D shape having multiple curved surfaces (for example, four curved surfaces) has appeared, and a technology capable of thermally transferring an ink layer of a necessary shape without deteriorating the quality of such a glass Is required.

Prior art relating to the present invention is Korean Patent Laid-Open Publication No. 2012-0110784 (published on October 10, 2012), which discloses a technology relating to a window glass printing apparatus.

The present invention provides a thermal transfer method for a multi-curved surface capable of proceeding a thermal transfer operation for a window glass having multiple curved surfaces while satisfying a high quality without a stable yield and quality deterioration.

The problems to be solved by the present invention are not limited to the above-mentioned problems, and other problems not mentioned here can be understood by those skilled in the art from the following description.

According to an aspect of the present invention, there is provided a method of manufacturing a multi-curved thermal transfer film, comprising: (a) forming a thermal transfer film for multiple curved surfaces; (b) preparing a jig to be heated to a set temperature, and placing a window glass having multiple curved surfaces on the jig; (c) aligning the position of the multi-curvature thermal transfer film so as to face the window glass, and placing the multi-curvature thermal transfer film on an upper side of the window glass; And (d) compressing and thermally transferring the multi-curved thermal transfer film disposed on the window glass using a vertically moving pad.

The step (a) includes the steps of: (a-1) preparing a thermal transfer film in which a protective film portion, a thermal transfer base film portion, and a thermal transfer ink layer are sequentially laminated; (a-2) setting a first cutting line corresponding to the window glass, and cutting only the thermal transfer base film portion and the thermal transfer ink layer except for the protective film portion along the first cutting line, Forming a cutting portion; And (a-3) setting a second cutting line corresponding to a corner portion where curved surfaces adjacent to each other in the window glass meet, and cutting the protective film portion, the thermal transfer base film portion, the thermal transfer And cutting the entire ink layer to form a second cutting portion.

At this time, in the step (a-1), the protective film part may be made of a PET material.

In the step (a-1), the thermal transfer ink layer may be laminated on at least one layer on the thermal transfer base film part. At this time, the protective film part may be made of PET material. Preferably a plurality of thermally-transferable ink layers stacked at an angle of 2 degrees or more, but are not limited thereto.

In the step (a-2), the first cutting line may be formed to correspond to a view window of the window glass, and may be a rectangular line having rounded corners.

In addition, in the step (a-2), the laser cutter moves along the first cutting line to perform cutting, and the laser cutter corresponds to the stack height of the thermal transfer ink layer and the thermal transfer base film A partial cutting can be performed by irradiating a laser.

Further, in the step (a-3), the second cutting line may be formed to overlap with a part of the first cutting line.

In the step (a-3), the laser cutting machine moves along the second cutting line to perform cutting, and the laser cutting machine cuts the thermal transfer ink layer, the thermal transfer base film part, and the protective film Cutting can be performed by irradiating a laser so as to correspond to the stack height.

In the step (b), the window glass may be formed into a curved surface with four surfaces except for a view window.

In the step (b), the jig may include a jig body having a receiving groove formed corresponding to an outer surface shape of the window glass so as to seat the window glass through an upper portion thereof, And a heating stick having a circular section having a diameter corresponding to the width width of the receiving recess so as to heat the window glass seated in the receiving recess to a set temperature.

In the step (b), the jig body may be made of aluminum, and the receiving groove may be anodized.

Also, in the step (b), the heating stick may be heated to a range of 80 to 200 ° C.

In the step (c), the multi-curved thermal transfer film is aligned in a predetermined position by a vision control method using four laser beams at the upper portion of the window glass, It can be irradiated toward each corner on the view area of the curved thermal transfer film.

In the step (d), the pad is made of an elastic material, and the pad can press the multi-curved thermal transfer film within a range of 300 to 400 kgf.

According to the embodiments of the present invention, it is possible to perform a thermal transfer operation on a window glass having multiple curved surfaces with a stable yield and a high quality, thereby having an advantageous effect of improving productivity and improving product competitiveness.

1 is a flowchart schematically illustrating a multi-curved surface thermal transfer method according to an embodiment of the present invention;
FIG. 2 is a flowchart schematically illustrating detailed steps of a step of preparing a thermal transfer film for a multi-curved surface according to an embodiment of the present invention. FIG.
FIGS. 3 and 4 are views illustrating steps of forming a first cutting portion according to an embodiment of the present invention. FIG.
FIGS. 5 and 6 are views for explaining a step of forming a second cutting portion according to an embodiment of the present invention. FIG.
7 is a process diagram briefly showing a state in which laser cutting processing is performed for forming first and second cutting portions.
8 is a view schematically illustrating a jig used in a multi-curved surface thermal transfer method according to an embodiment of the present invention.
9 is a view schematically showing a process of disposing a window glass and a multi-curved thermal transfer film on a jig according to an embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention and the manner of achieving them will become apparent with reference to the embodiments described in detail below with reference to the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. To fully disclose the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. The following terms are defined in consideration of the functions in the embodiments of the present invention, which may vary depending on the intention of the user, the intention or the custom of the operator. Therefore, the definition should be based on the contents throughout this specification.

Generally, an ink layer is formed around an outer periphery of a view window (or a window) in order to realize appearance aesthetics and other functional effects in a glass of a display device.

In recent years, there has been provided a window glass having a 3D shape having multiple curved surfaces (e.g., four curved surfaces). In this type of glass, it is also possible to quickly and accurately transfer an ink layer of a required shape without deteriorating the quality A technology is required.

FIG. 1 is a flow chart briefly illustrating a multi-curved surface thermal transfer method according to an embodiment of the present invention. FIG. 2 is a flow chart schematically illustrating details of a step of preparing a thermal transfer film for multiple curved surfaces according to an embodiment of the present invention. And FIGS. 3 to 9 are diagrams illustrating each process step.

Referring to FIG. 1, a multi-curved surface thermal transfer method according to an exemplary embodiment of the present invention includes forming a multi-curved thermal transfer film S100, controlling a jig heating temperature S200, A seating step S300, and a multi-curved glass thermal transfer step S400 using pad compression.

2, the thermal transfer film forming step S100 for a multi-curved surface of the present invention includes a thermal transfer film preparing step S110, a first cutting part forming step S120, a second cutting part forming step S130) and a multi-curved thermal transfer film forming step (S140).

The window glass 10 (see FIG. 9) is formed in a three-dimensional shape having multiple curved surfaces, unlike a plate-shaped glass applied to a conventional display device (such as a smart phone). More specifically, the window glass 10 (see FIG. 9) is formed of a rounded surface having four surfaces except for a view window (that is, a surface corresponding to the front surface of a smartphone or the like to which the screen is output). Rounded corners can be formed between these four curved surfaces.

In order to form an ink layer (i.e., a thermal transfer ink layer) B on a window glass 10 (see Fig. 9) having such a shape, at least two films, i.e., an OCA film (not shown) and a UV release film Not shown) was used. For example, first, a process of joining the OCA film formed with the thermal transfer ink layer (B) with a UV release film, and a process of joining the joined OCA film and UV release film to the window glass 10 A laminating process was required. As a result, there has been a problem in work flow and yield, but the present invention can solve such a problem and satisfy a stable yield and a high quality.

The thermal transfer film forming step (S100)

As shown in FIG. 2, the thermal transfer film preparing step S110, the first cutting part forming step S120, the second cutting part forming step S130, And a step S140 of forming a curved thermal transfer film.

The thermal transfer film preparation step (S110)

This step corresponds to the step of preparing a thermal transfer film in which a protective film portion, a thermal transfer base film portion and a thermal transfer ink layer are sequentially laminated.

Referring to FIG. 3, a thermal transfer film 100 is prepared. The thermal transfer film 100 may be provided in the form of sequentially stacking a protective film portion 120, a thermal transfer base film portion 110, and a thermal transfer ink layer (B).

The protective film part 120 constituting the thermal transfer film 100 in this step may be made of a PET material, but is not limited thereto and materials having similar characteristics can be used.

The thermal transfer base film 110 is a base of a thermal transfer film, and is a film-like member in which a thermal transfer ink layer (B) is formed by printing.

The thermal transfer ink layer B is formed to have a predetermined shape (for example, a rectangle corresponding to the view window of the window glass 10) at the top of the thermal transfer base film 110, And an ink layer (Ink layer) for providing an ink layer.

Further, the hue of the thermal transfer ink layer (B) is not limited to a specific color, and can be selected from among various colors.

In the first cutting portion forming step S120,

In this step, a first cutting line is formed corresponding to the window glass, and only the thermal transfer base film portion and the thermal transfer ink layer are cut off along the first cutting line except for the protective film portion, 1 cutting portion.

Referring to FIG. 3, in the thermal transfer film 100 prepared in the previous step, a first cutting portion 200 is formed.

The first cutting portion 200 is formed along the first cutting line set corresponding to the shape and size of the window glass 10 (see FIG. 9).

4, the first cutting portion 200 is formed by partially removing only the remaining portions except the protective film portion 120, that is, the thermal transfer ink layer (B) and the thermal transfer base film portion 110 (This is referred to as 'half cutting').

For example, the first cutting portion 200 may include an inner cutting portion 210 and an outer cutting portion 220. The first cutting portion 200 may be formed to form the first cutting portion 200, May be formed of a rectangular line whose corner portions are rounded so as to correspond to the view window of the window glass 10 (see Fig. 9) as shown in Fig.

The inner cutting portion 210 constituting the first cutting portion 200 is formed by cutting the thermal transfer ink layer B and the thermal transfer base film portion 110 at the same time, It may be formed by cutting only the thermal transfer base film portion 110 with an interval outside the thermal transfer ink layer (B).

In order to form the first cutting portion 200, the laser cutting machine 500 (see FIG. 7) moves along the set first cutting line to perform the cutting.

The laser cutter 500 shown in FIG. 7 is disposed at a position where the second cutting unit 300 will be described later, and is not disposed at a position where the first cutting unit 200 is cut. However, The first and second cutting units 200 and 300 can be formed by moving the laser cutting machine 500 (see FIG. 7).

4, while moving the laser cutting machine 500 (see FIG. 7) along the first cutting line, the laser L is irradiated onto the thermal transfer ink layer B and the thermal transfer base film portion 110, So that the partial cutting can be performed.

In the second cutting portion forming step (S130)

In this step, a second cutting line is formed corresponding to a corner portion where the curved surfaces adjacent to each other in the window glass meet, and the protective film portion, the thermal transfer base film portion, the thermal transfer And cutting the entire ink layer to form the second cutting portion.

Referring to FIG. 5, the second cutting unit 300 is formed on the thermal transfer film 100 in which the first cutting unit 200 is formed in the previous step.

The second cutting portion 300 is formed along a second cutting line set corresponding to a corner portion where curved surfaces adjacent to each other in the window glass 10 (see FIG. 9) meet. Specifically, And cutting the entirety of the ink layer B, the thermal transfer base film 110, and the protective film 120 (referred to as "full cutting").

For example, the second cutting portion 300 may be formed to overlap with the first cutting portion 200, and more specifically, a portion of the inner cutting portion 210. The rounded corner portion of the window glass 10 (E.g., four) in a shape similar to "a"

The second cutting unit 300 moves the laser cutter 500 (see FIG. 7) along the set second cutting line to perform cutting. 7, the laser cutter 500 moves along a predetermined path along a second cutting line shown in FIG. 7, and irradiates the laser L. The laser L irradiated to form the second cutting portion 300, Can be irradiated with an intensity capable of cutting both of the thermal transfer ink layer (B), the thermal transfer base film portion (110), and the protective film portion (120).

Preparing a thermal transfer film for multiple curved surfaces (S140)

Can be used for thermal transfer of the window glass 10 having four curved surfaces through the above-described thermal transfer film preparing step S110, the first cutting part forming step S120 and the second cutting part forming step S130 A multi-curved thermal transfer film is provided. By thus preparing the multi-curved thermal transfer film 100 formed in this way, the productivity of the thermal transfer operation can be improved.

As described above, the thermal transfer film for multi-curved surface is formed through the steps of preparing the thermal transfer film (S110), forming the first cutting portion (S120), forming the second cutting portion (S130) The film is ready.

The jig heating temperature control step (S200)

This step is a jig heating temperature control step, in which a jig heated to a set temperature is prepared, and a window glass having multiple curved surfaces is mounted on the top of the jig.

Here, the window glass 10 (see FIG. 9) may be formed into a curved surface with four sides except a view window. And the edge part where the four curves meet can be provided in rounded form.

Referring to FIG. 8, the illustrated jig 600 has a function of being heated to a set temperature. On the upper portion of the jig 600, receiving grooves 620 (see FIG. 9) for receiving a window glass 10 ).

For example, the jig 600 includes a jig body 610, a heating stick 630, and a heating control unit 650.

At this time, the receiving groove 620 in a rounded shape is formed through the upper part of the jig body 610, and may be formed corresponding to the outer surface shape of the window glass so as to seat the window glass 10 (see FIG. 9) , But it is not necessarily limited to the illustrated shape. That is, it can have various other shapes.

The heating stick 630 is disposed to penetrate through the jig body 610 so as to heat the window glass 10 (see FIG. 9) or the window glass 10 The diameter of the receiving groove 620 may be equal to or slightly smaller than the width of the receiving groove 620. Although the bar is shown as a rod-shaped stick having a circular cross section, it may have a different shape. The heating stick 630 is controlled by the heating control unit 650, and is preferably heated within a range of 80 to 200 占 폚. If the temperature is less than 80 ° C, the heating effect is insignificant when heat is applied by the pad pressing method. Conversely, when the temperature exceeds 200 ° C, there may be a problem due to excessive heating.

The jig body 610 may be made of a lightweight metal material, for example, an aluminum material, as long as it is lightweight and structurally high in rigidity. However, the receiving groove 620 is preferably anodized, and since it is a portion where the thermal transfer operation is repeatedly performed, the anodizing treatment can increase the wear resistance and improve the corrosion resistance.

The thermal transfer film aligning and seating step (S300)

In this step, the thermal transfer film for multiple curved surfaces is aligned, and the thermal transfer film for multiple curved surfaces is aligned to face the window glass placed on the jig. Then, the thermal transfer film for multiple curved surfaces is placed on the upper side of the window glass This is equivalent to a step of arranging a face to face.

Referring to FIG. 9, the window glass 10 is seated in the receiving groove 620 of the jig 600. The multi-curved thermal transfer film is positioned so as to face the window glass 10. The thermal transfer film for the multi-curved surface is formed by a four-laser beam 710, 720, 730, and 740 at the top of the window glass 10, it can be aligned to the correct position by a vision control method.

For example, each of the four laser beams 710, 720, 730, and 740 is irradiated toward each corner on the view area VA of the multi-curved thermal transfer film to quickly move the facing position with the window glass 10 And can be accurately aligned. In order to control the laser beams 710, 720, 730, and 740, a vision control unit 700 may be provided.

Multiple Curved Glass Thermal Transfer using Pad Compression (S400)

This step corresponds to a step of performing a thermal transfer by pressing a thermal transfer film for multiple curved surfaces disposed on a window glass by using a vertically moving pad, which is a multi-curved glass thermal transfer step using pad pressing.

9, the window glass 10 is placed in the receiving groove 620 of the jig 600 and the thermal transfer film for multiple curves is formed on the upper side of the window glass 10 using the vision control in the previous step And is arranged on the upper side of the window glass 10 in a face-to-face manner.

The window glass 10 is heated to a predetermined temperature by a heating action of the heating stick 630 heated to a predetermined temperature. At this time, the window glass 10 is heated The multi-curved thermal transfer film is squeezed. Thus, the thermal transfer ink layer (B) can be thermally transferred to the window glass (10).

On the other hand, when the pad is compressed, the multi-curved thermal transfer film can be effectively adhered to the window glass 10 having a three-dimensional shape by the first and second cutting units 200 and 300 (see FIG. 5) It is possible to prevent the deterioration of the quality and to produce a high quality product.

As described above, according to the structure and operation of the present invention, thermal transfer can be performed while satisfying high quality without deteriorating the yield and quality of the thermal transfer operation for a window glass having multiple curved surfaces.

In particular, it is possible to form a thermal transfer film for multiple curves in a quick and simple way by means of laser cutting, so that the laser cutting process for one thermal transfer film and the thermal transfer technology can completely solve the existing problems have.

Furthermore, when the thermal transfer film is stably brought into close contact with the window glass having multiple curved surfaces, it is possible to prevent defective transfer such as distortion or distortion of the transferred ink layer when the thermal transfer operation is performed through the pad pressing.

Although a specific embodiment of the multi-curved surface heat transfer method of the present invention has been described, it is apparent that various modifications can be made without departing from the scope of the present invention.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention, and are not intended to be exhaustive or to limit the scope of the invention. All changes or modifications that come within the scope of the equivalent concept are to be construed as being included within the scope of the present invention.

S100: Thermal transfer film forming step for multiple curves
S110: Preparation of thermal transfer film
S120: First cutting portion forming step
S130: second cutting portion forming step
S140: Step of preparing a thermal transfer film for multiple curved surfaces
S200: Jig heating temperature control step
S300: Thermal transfer film alignment and seating phase for multiple curves
S400: Multi-curved glass thermal transfer step with pad crimping
B: thermal transfer ink layer
L: Laser
VA: view area
10: Window glass (or glass)
10a, 10b, 10c and 10d:
10e, 10f, 10g, 10h: corner portion
100: Thermal transfer film for multiple curved surfaces
110: thermal transfer base film portion
120: protective film part
200: first cutting portion
210: inner cutting portion
220: outer cutting portion
300: second cutting portion
500: laser cutting machine
600: jig
610: jig body
620: Receiving groove
630: Heating Stick
650:
700:
710, 720, 730, 740: laser light

Claims (10)

(a) forming a multi-curved thermal transfer film;
(b) preparing a jig to be heated to a set temperature, and placing a window glass having multiple curved surfaces on the jig;
(c) aligning the position of the multi-curvature thermal transfer film so as to face the window glass, and placing the multi-curvature thermal transfer film on an upper side of the window glass; And
(d) pressing and thermally transferring the thermal transfer film for multiple curves arranged in a face-to-face relationship with the window glass by using a vertically moving pad,
The step (a)
(a-1) preparing a thermal transfer film in which a protective film portion, a thermal transfer base film portion, and a thermal transfer ink layer are sequentially laminated;
(a-2) setting a first cutting line corresponding to the window glass, and cutting only the thermal transfer base film portion and the thermal transfer ink layer except for the protective film portion along the first cutting line, Forming a cutting portion; And
(a-3) setting a second cutting line in correspondence with a corner portion where curved surfaces adjacent to each other in the window glass meet, and setting the second cutting line along the second cutting line so that the protective film portion, the thermal transfer base film portion, And cutting the entire layer to form a second cutting portion.
delete The method according to claim 1,
In the step (a-1)
Wherein the thermal transfer ink layer is laminated on at least one layer from the top of the thermal transfer base film part.
The method according to claim 1,
In the step (a-2)
Wherein the first cutting line is formed in correspondence with a view window of the window glass and is formed of a rectangular line whose corner portions are rounded,
The laser cutting machine moves along the first cutting line to perform cutting,
Wherein the laser cutter irradiates a laser so as to correspond to a height of the lamination of the thermal transfer ink layer and the thermal transfer base film part to perform partial cutting.
The method according to claim 1,
In the step (a-3)
The second cutting line is formed overlapping with a part of the first cutting line,
The laser cutting machine moves along the second cutting line to perform cutting,
Wherein the laser cutter irradiates a laser beam corresponding to a stack height of the thermal transfer ink layer, the thermal transfer base material film, and the protective film to cut the laser beam.
The method according to claim 1,
In the step (b)
Wherein the window glass
Wherein the four surfaces except the view window are formed as curved surfaces.
The method according to claim 1,
In the step (b)
The jig,
A jig body having a receiving groove formed corresponding to an outer surface shape of the window glass to seat the window glass through an upper portion;
A plurality of curved surface heaters, which are arranged to penetrate the jig body and have a circular cross-sectional heating stick having a diameter corresponding to the width of the receiving groove so as to heat the window glass placed in the receiving groove to a set temperature, Way.
8. The method of claim 7,
In the step (b)
Wherein the jig body is made of an aluminum material, and the receiving groove is anodized.
The method according to claim 1,
In the step (c)
The multi-curved thermal transfer film is aligned in a predetermined position by a vision control method using four laser beams at an upper portion of the window glass,
Wherein each of the four laser beams is irradiated toward each corner on a view area of the multi-curved thermal transfer film.
The method according to claim 1,
In the step (d)
Wherein the pad is made of an elastic material.

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