TECHNICAL FIELD OF THE INVENTION

The invention relates to a method for providing a hole or opening into a component, such as e.g. to a watch dial, where the component comprises protective layers and a display layer arranged between the protective layers and wherein said display layer comprises an electrophoretic ink paper layer or other polymer film having cavities with fluid used advantageously for displaying purposes. In addition the invention relates to a component, such as a watch dial, which comprises at least one hole or opening manufactured by the method.

BACKGROUND OF THE INVENTION

Electrophoretic ink paper displays (electrophoretic displays) are nowadays used also in components, such as in watch dials, where holes or other openings must be provided to the electrophoretic ink paper display for example for axis of quartz or mechanical movement of the watch. The hole or opening may also be provided for other purposes, and it might be provided only to a certain depth of the layer (partially through) or totally through said display layer of the electrophoretic ink paper. According to an example another display or other relevance may be located below the first one so that the opening in the first one will enable view of the second display or other relevance.

Electrophoretic display comprises titanium dioxide particles dispersed in oil based or other highly viscous medium, e.g. hydrocarbon oil, and some dye- material is also used along with surfactants and charging agents that cause the particles to take on an electric charge. The medium are arranged typically into cavities forming pixels of the display, and the cavities are approximately in a range of micrometers in diameter. When the hole is provided into the electrophoretic display, the cavities having oil based or other highly viscous medium, ink or dye-material and other particles, will be broken, whereupon the medium leaks away from the cavities, which again make the display non-active also at the rim area of the hole or opening. In addition moisture will also be absorbed or diffused into or out the structure of the electrophoretic display, which additionally destroy the active area of the electrophoretic display.

Previously the holes are drilled through the component thereby breaking the layers and cavities of the electrophoretic display, as can be seen in prior art Figure 1. The component 100 typically comprises protective layers 101 , 102 and a display layer 103 arranged between the protective layers. In addition the component 100 also comprises a printed circuit 104 or other backplane with suitable electronics for controlling the display. According to prior art methods the protective layer 101 is manipulated, such as treated by heating treatment, after the hole drilling to cover the surface of the hole 105 so to prevent the moisture absorption or diffusion to the structure of the electrophoretic ink paper 103. So in order to enable introduction of the protective layer 101 into the hole surface, the non-active area 105a of the hole is quite large, typically 5-7 millimeters, even though the final diameter 105b of the through hole is very often around of 2 millimeters. Thus the non- active or blind area is at least the area covered by the initial diameter 105a or even little bit larger due to moisture absorption, diffusion or leaking of the oil based medium of the electrophoretic display, which is clearly a disadvantage. The active are is denoted by reference number 106.

SUMMARY OF THE INVENTION

An object of the invention is to alleviate and eliminate the problems relating to the known prior art. Especially the object of the invention is to provide a method for providing a hole or opening into a component, such as a watch dial, comprising protective layers and a display layer between the protective layers, wherein said display layer comprises an electrophoretic ink paper layer or other polymer film having cavities with fluid used advantageously for displaying purposes. In particularly the object of the invention is to provide the hole or opening so that to minimize the non-active area and maximizing the active area of the display.

The object of the invention can be achieved by the features of independent claims. The invention relates to a method for providing a hole or opening according to claim 1. In addition the invention relates to a component, such as a watch dial, with a hole or opening manufactured with the method, according to claim 14.

According to an embodiment of the invention a hole or opening (hole hereinafter) is provided into a component, such as a watch dial, where the component comprises protective layers and a display layer between the protective layers. The display layer comprises an electrophoretic ink paper layer known from the prior art related to technical field of electrophoretic ink papers. In the method a first hole is provided at least partially through the display layer of the component, the first hole having a first diameter. The hole is provided advantageously by laser. The diameter of the first hole is advantageously in a range of 1-5 mm. Secondly moisture sealing material differing from the material of the protective layer is provided in the contact with the first hole in order to seal the surface of the hole of the electrophoretic ink paper layer.

The embodiment offers clear advantages namely when using the moisture sealing material, which is separate from the protective layer, the diameter of the first hole (and the blind area) can be very small. In addition the sealing material separate from the protective layer can be applied very accurately in the contact with the hole surface, which still seal the surface of the hole and thereby prevents any leakages or moisture absorption or diffusion in an effective way. In addition the separate moisture sealing material is very easy, cost effective and fast way to seal the hole.

According to an embodiment the surface of the first hole is cleaned before applying said sealing material in order to remove damaged capsules or cavities of electrophoretic ink and thereby enabling more reliable contact and sealing with the moisture sealing material. The cleaning can be done mechanically and/or using specific chemical agent.

According to an embodiment the first hole is filled with the moisture sealing material, whereafter a second hole with a second diameter is provided essentially concentrically with the first one. The sealing material may be provided by a dispenser or screen printing method, as an example. According to an advantageously embodiment at least partial vacuum may be introduced into the first hole for facilitating the sealing material apply into the first hole. The sealing material may be e.g. UV curable, thermally curable, room temperature curable, and/or humidity curable sealing material, whereupon it is cured after introduction to the hole by suitable treatment, such as UV radiation, thermal treatment or humidity treatment before providing said second hole, for example. The sealing material may comprises silicone, UV acrylate, epoxy or polyurethane, for example.

If the first hole is filled with the sealing material, the second hole is advantageously provided to said first hole filled by said sealing material in order to provide a second hole to said component, the second hole having a second diameter being smaller than said first diameter of the first hole. The diameter of the second hole is typically in a range of 0.3-2 mm, for example.

It is to be noted that if only the first hole (or opening) is provided, it may be provided to so enable bending of the component around said opening. This might be beneficial for example the component is a display of a watch dial, which should be bent along the wristband. In this case the sealing material may be provided in the contact with the surface of the opening for example at the same time when the component is bent and there might be no need to fill the hole before that. However, according to an embodiment the first hole may be totally filled with the sealing material, after which said second hole is provided at least partially though the sealing material for example after the sealing material is cured, e.g. hardened. This is the case e.g. when a axis of a quartz or mechanical movement is introduced through the hole.

In the method the first hole is advantageously provided by a first laser beam. The second hole may be provided e.g. by a second laser beam or drilling the moisture sealing material. This is advantageously done after hardening the moisture sealing material.

The component is advantageously e.g. a watch dial comprising protective layers and an electrophoretic ink paper layer between the protective layers. Advantageously the final product, such as the watch dial comprises suitable controlling means in the connection with the electrophoretic ink paper layer. The controlling means are advantageously configured to manipulate charging agents of the electrophoretic ink paper layer in order to provide an electrophoretic display, and the controlling means are advantageously arranged in a printed circuit, or other backplane, which can be flexible or rigid. According to an example the controlling means are formed in a segmented form in order to achieve segmented display. Also other implementations are naturally possible. According to the invention the component additionally comprises at least a first hole or opening provided at least partially through the display layer. Additionally the component may also be provided with a second hole or opening. The component with the hole(s) is manufactured by processes as discussed in this description.

The present invention offers advantages over the known prior art, such as very accurate and fast method for providing holes or openings into the electrophoretic ink paper layer as well as also to or other polymer film having cavities with fluid. In addition the non-active area can be kept very small, whereupon the active area of the component, such as a watch dial, can be maximized. In addition the sealing material separate from the protective layer can be applied very accurately in the contact with the hole surface, which still seal the surface of the hole and thereby prevents any leakages or moisture absorption or diffusion in an effective way. In addition the separate moisture sealing material is very easy, cost effective and fast way to seal the hole. In addition the final product, such as a watch dial, is aesthetically very high quality because the very small hole through which the axis of the movement can be applied.

BRIEF DESCRIPTION OF THE DRAWINGS

Next the invention will be described in greater detail with reference to exemplary embodiments in accordance with the accompanying drawings, in which:

Figure 1 illustrates a prior art method for providing a hole to the component,

Figures 2A-2D illustrate a principle of an exemplary method for providing a first and second holes to the component according to an advantageous embodiment of the invention,

Figures 3A-3D illustrate a principle of an exemplary method for providing a hole to the component to be bent according to an advantageous embodiment of the invention. DETAILED DESCRIPTION

Figure 1 illustrates a prior art method for providing a hole to the component and is already discussed in the connection of the background of the invention portion of this document.

Figures 2A-2D illustrate a principle of an exemplary method 200 for providing a first 201 and second 202 holes to the component 203 according to an advantageous embodiment of the invention. The exemplary component in Figures 2A-3D is a watch dial comprising an electrophoretic ink paper layer 204 as a display, and protective layers 205, 206 around the electrophoretic ink paper layer 204 (display layer hereafter).

In the method the first hole 201 is provided at least partially through the display layer 204 of the component. The first hole has a first diameter and is advantageously provided by a laser 207.

Secondly moisture sealing material 213 differing from the material of the protective layers 205, 206 is provided into the first hole 201 in order to seal the surface of the hole 201 of the electrophoretic ink paper layer 204 and thereby preventing moisture absorption or diffusion to the electrophoretic ink paper as well as preventing also leakages of the oil based or other medium from the electrophoretic ink paper. The surface of the first hole 201 may also be rinsed by suitable rinsing apparatus 208 before applying the sealing material.

The sealing material may be provided by a dispenser 209 or screen printing, as an example. Also partial vacuum may be introduced into the first hole 201 advantageously via opposite side than where the sealing material is introduced. In practice the vacuum can be introduced via a small hole 210 at the bottom of the component (extending through the bottom plate, such as a printed circuit 212) by using suitable vacuum pump 21 1. The small hole 210 may be provided e.g. by the laser 207 or drilling.

The sealing material may be e.g. UV curable, thermally curable, room temperature curable, and/or humidity curable sealing material, whereupon it is cured after introduction by a suitable treatment means 215, such as by a UV radiator, heater or humidity damper. The second hole 202 with a second diameter is then provided essentially concentrically with the first hole 201 into the sealing material 206 for example by laser 207 or drilling 214. The diameter of the second hole is advantageously smaller than the diameter of the first hole. Advantageously the difference of the diameters is provided so that enough sealing material is left in the contact with the electrophoretic display 204 and thereby preventing moisture absorption.

The holes 201 , 202 may be provided to the component 203 having only protective layers 205, 206 and the electrophoretic layer 204 between them, whereupon the suitable printed circuit 212 or other backplane with suitable controlling means for controlling the component and especially the display 204 is provided. However, it is also possible to provide the holes 201 , 202 to the component already comprising said printed circuit 212 or other backplane. The printed circuit or other backplane comprises material differing from the protective layers as well as from the electrophoretic display, such as at least one of the following: Au (gold), Ni (Nickel) or Cu (Copper), (Ag) Silver. Then the power and/or the wavelength of the laser beams used for providing the hole(s) are advantageously chosen so to machining the display layer comprising the electrophoretic ink paper layer in suitable manner. In addition at least the second hole 202 is advantageously provided to extend through the printed circuit 212 or other backplane in order to provide hole for the axis of the movement.

Figures 3A-3D illustrate a principle of an exemplary method 300 for providing a hole (or opening) 301 to the component 203 to be bent. In this method the hole 301 is not extending through the component, but only thought the bottom protective layer 206 and at least partially through the electrophoretic display 204. The hole is provided advantageously by the laser 207 and can be provided similarly than in the method 100. The form of the hole 301 is advantageously formed as an opening (with a certain angle, such as an opening triangle) so to provide a structure, which is easy to bend around said opening (see especially Figures 3C-3D). It is to be noted that one or more holes or openings can be provided.

The moisture sealing material 213 may be applied either at least partially into the hole 301 or alternatively arranged so that it will be applied in the contact 302, 303 of the first hole at least when the component is bent and/or arranged on the top of the printed circuit 212 or other backplane. The invention has been explained above with reference to the aforementioned embodiments, and several advantages of the invention have been demonstrated. It is clear that the invention is not only restricted to these embodiments, but comprises all possible embodiments within the spirit and scope of the inventive thought and the following patent claims. It is to be noted plurality of different kinds of holes and openings can be provided to the component, such as the component may comprise both the holes 201 , 202 for inserting e.g. a axis through the component, as well as openings 301 so to bend said component around the openings.

In addition it is to be noted that even if the electrophoretic ink paper layer has been disclosed as an example, the invention can also be applied with other polymer film layers having cavities with fluid and used advantageously for displaying purposes.