The present invention relates to a multi-layer film designed to be attached on a front display of electronic devices, such as mobile phones, mobile music players, televisions, computers and virtually any electronic device that has an electronic display screen that is visible and readable by a user. More particularly, the present invention relates to a multi-layer film with an outer surface that has a sufficient scratch resistant property so that the outer layer resists scratches during use, having a separator that can easily be cut accurately in a nearly straight line and leaving almost no residual cutting dust on an adhesive layer of the multi-layer film, and providing an option to include an additional cleaning function.
Recently, multi-layer films have been used for many different purposes on a variety of screens for electronic products, such as displays of mobile phones, music players, digital organizers and televisions. These devices feature an electronic screen that displays images, graphics, videos, words, pictures and almost anything else that can be visible to the user. The multi-layer sheets can be of various types, and for example, can be of many types, including a clear screen protector for mobile devices, a polarizing sheet, a phase difference sheet, an optical compensation sheet, and a brightness enhancement sheet. Generally, the multi-layer film sheets are clear, however, colored film sheets have also been used for special purposes such as a privacy protection purpose. Even with privacy films there is a desire to have these films be as clear as possible so as to not obscure the device screen and the clarity of the screen when facing the user.
Conventional multi-layer film A in
The conventional multi-layer film A has a problem of being positioned on the display because the user needs to guess an appropriate position after removing the separator or as gradually removing the separator. Also, placing the film on an appropriate position without leaving any bubble takes experience and practice.
To solve the identified problems associated with the conventional film, another type of separator has been developed where a separator 30 has a slit S across the film (back split slit) which enables users to position a part of the film A after removing another part of the separator 30 from the slit S. An adhesive layer 20 is exposed after removing part of the separator 30 and the adhesive layer is placed on a part of the display, and the other part of the film A with the separator 30 is lifted to remove the other part of the separator 30 finally placing the other part of the film A on an appropriate position of the display.
However, this approximately half-slit separator has a problem of generating cutting dust that ultimately ends up on the adhesive layer 20, and the amount of the dust and the possibility of generating the dust increases as the half-slit line becomes longer.
In addition, during the slitting process a blade may accidentally extend into the adhesive layer 20 which create a chance of keeping air in a slit gap in the adhesive layer 20 and also a chance of leaving a white line J as shown in
Furthermore, during the slitting process the blade may accidentally cut deeper, causing a damage to the clear material base sheet 10. In an extreme situation, the blade extends further to slightly cut the entire cross line of the film A possibly causing significant damage to the film A.
Japanese Unexamined Patent Publication No. 2007-156066
The present invention was made to eliminate the above-identified problems. Therefore, an object of this invention is to provide a multi-layer film showing a sufficient scratch resistant property on the outward facing film, having a clear material base sheet, an adhesive layer applied on a back surface of the clear material base sheet, and a separator temporarily placed and adhered on the adhesive layer, where the separator has a strong tear directionality in one direction allowing the user to tear the separator cleanly and in a straight line and after the separator is torn and removed it exposes a section of the adhesive layer whereafter the user can accurately and easily position the clear material base sheet on the device display. It is another object of this invention to enable the user to tear the predetermined portion of the film cleanly and almost straight without the risk of bubble and white line formation problems.
The multi-layer film of this invention comprises a clear material base sheet, an adhesive layer formed on one side of the clear material base sheet with a scratch resistant outer surface on the other side of the clear material base sheet, and a separator that has strong tear directionality that is temporarily placed on the adhesive layer. The multi-layer film can also have an additional adhesive layer formed on the separator temporarily fixed on the first adhesive layer and an additional separator temporarily fixed on the second adhesive layer. The separator can have at least one slit in a direction to be torn.
The clear material base sheet of the multi-layer film can have an effective area to be placed on an object and a disposable area, and at least one slit is formed on any one or all of the separators and clear material base sheet.
A slit line can be formed at a boundary between said effective area and the disposable area.
The separator can be larger than the clear material base sheet, and at least one slit can be formed on the separator.
The multi-layer film A of this invention has the separator 30 with strong tear directionality and a slit S in the tear direction, allowing the user to tear the separator in a nearly straight line, and this clean, straight tearability facilitates and simplifies the positioning and installation process of the film on the display. During the manufacturing and forming process of the slit S on the film A, slitting all the way crossing the separator as in the conventional art using the blade is not necessary, which eliminates a chance of damaging the film sheet by the blade extending into undesirable areas of the adhesive layer or the clear material base sheet.
Such extensive cutting would go into the adhesive layer, which causes a chance of leaving bubbles in a cutting gap or leaving the white line which can be eliminated hereby. No noticeable cutting dust can be created, and therefore a chance of leaving the cutting dust on the adhesive layer is very slim.
The clear material base sheet 10 can be designed smaller than the separator, and at least one slit S can be formed on a portion of the separator not superposing the clear material base sheet 10, thereby removing the above-identified problems with the knife and cutting.
Alternatively, the clear material base sheet 10 has an effective area which is actually used as a film and a disposable area which can be disposed after installation of the film on the display. In this case, the slit S can be made in the disposable area and the cut can extend to the clear material base sheet 10, which makes the blade slitting process much easier.
Embodiments of this invention will be explained next with accompanied drawings.
The following embodiments are merely examples of this invention, and therefore this invention is not limited to the descriptions below.
The multi-layer film A according to this embodiment is a rectangular film having a clear material base sheet 10, an adhesive layer 20, and a separator 30.
This multi-layer film is structured so that a front surface of the clear material base sheet 10 is exposed to the user and this front surface has scratch resistant properties so as to protect the film surface when used by the user, the adhesive layer 20 is created on a back surface of the clear material base sheet 10, and the separator 30 is temporarily placed and attached to the adhesive layer 20.
The clear material base sheet 10 for example can be an entirely clear material, it can be a reflection sheet, a polarizing sheet, a clear sheet with decoration, a semi-transparent sheet, a phase difference sheet, a brightness enhancement sheet, a protective sheet, an anti-reflective sheet, an electromagnetic wave shield sheet, an optical compensation sheet, a near-infrared ray filter sheet, and a color matching sheet. However, in any case, the film must be entirely clear or almost entirely clear so that visibility is not obstructed as it is typically placed on the screen surface of an electronic device and the screen surface must be visible to the user or else the film is useless.
The separator 30 can be a synthetic resin such as polyethylene, polypropylene or polyethylene terephthalate. The separator 30 of this invention preferably has a strong tear directionality, and for example, a monaxial stretching or one-way drawing sheet may be used as the separator 30. During manufacture, the separator 30 is stretched in one direction for facilitating the tearing by the user. In this embodiment, the slit S is made in the drawing direction of the film so as to facilitate the initial tearing step. Preferably, the separator 30 is transparent and is treated with a silicone, long-chain alkyl, and fluorine in order to smoothly detach and remove from the adhesive layer 20. The thickness of the separator 30 is not limited to a particular size; however, generally a thickness of between 20 μm and 200 μm is a popular thickness.
A material for the adhesive layer 20 is not particularly limited; however, the adhesive agent such as an acrylic adhesive agent, rubber adhesive agent, or silicone may be used here. In consideration of the cost, transparency, and durability, an acrylic polymer is preferable. The thickness of the adhesive layer 20 is not limited to a particular size either; however, generally the thickness of between 10 μm and 100 μm is popularly used.
In this embodiment, a short slit S is located at an intermediate portion of the multi-layer film A, and the slit S is only formed in the separator 30. The slit S is a cut in the tearing direction of the separator 30 along an invisible drawing line of the separator 30.
The slit S can be made for example by Timpson Press Blade; however, because of the quality of the finished end surface, a laser cutter is preferable.
Here, the installment process of the multi-layer film on the electronic device display will be explained with reference to the drawings. The user picks a first side edge of the slit S on the separator 30 and starts to tear straight down and across as shown in
It is preferable to tear the first portion of the separator 30 nearly straight, and at least when the tearing starts at the slit S in the vertical direction, the tearing line should be straight enough to end at the opposite side thereof at the opposite side line of the separator 30.
The separator 30 is positioned and adhered on the adhesive layer 20 which is layered on a back surface of the clear material base sheet 10, and therefore when the first portion of the separator 30 is being torn at the slit S, the second portion of the separator 30 is still adhered to the adhesive layer 20, which makes it easier to tear the first portion of the separator 30.
After removing the first portion of the separator 30, the first portion of the adhesive layer 20 is exposed, as shown in
The process of installing the right portion of the multi-layer film is illustrated in
The right portion of the adhesive layer 20 can now be gradually placed on the display as removing the right portion of the separator 30, thereby completing the installation of the multi-layer film onto the electronic device display screen.
Accordingly, positioning and aligning the film on the display is extremely easy.
Because of the easy, clean tearability of the separator sheet, the slit S can be very short, and therefore the blade and the S slit does not need to go into the clear material base sheet 10 during the slitting process at the film manufacturing site and this prevents damage to the clear material base sheet.
Cutting dust that is typically and generally generated while tearing the separator 30 can hardly be seen in this invention because of the one-way drawing separator 30, thereby leaving no cutting dust to adversely affect the appearance of the film after installation.
The slit S can be short because the separator 30 can easily be torn straight along the drawing line of the one-way drawing sheet.
The multi-layer film sheet A of the second embodiment has the slit S in an intermediate portion of the separator 30, as in the first embodiment, but the slit S is deeper than the slit S in the first embodiment so that it goes into the adhesive layer 20. Although the slit S is short and should stop at the adhesive layer 20, the quality of the film A after completion of the installation would not be affected even if the blade accidentally goes into the clear material base sheet 10. The installation process is the same as the first embodiment and the explanation of which will be omitted here.
The slit S in this embodiment is positioned at a central portion of the multi-layer film A within the disposable area P2, and therefore slitting deeply into the clear material base sheet 10 has no adverse effect to the pro-installed film.
The blade can cut through the clear material base sheet 10, adhesive layer 20, and separator 30 as long as the slit S does not extend beyond the disposable area P2, and no sensitive half cut process without reaching the clear material base sheet 10 is not necessary.
A process of installing the film A is the same as the description in the first embodiment; however, the disposable area P is preferably removed from the detach line D prior to the installment.
In order to install the multi-layer film A of this embodiment, the left portion of the second separator 50 is removed first. Here, the left portion of the second separator 50 is torn from the slit S in the direction of orientation or along the vertical line in
The second separator 50 is positioned and adhered on the second adhesive layer 40, and therefore when the left portion of the second separator 50 is torn from the slit S, the right portion of the second separator 50 is still adhered to the second adhesive layer 40, which makes it easier to tear the left portion of the second separator 50.
Accordingly, the left portion of the second separator 50 is removed to expose the second adhesive layer 40, which is placed on the display. The right portion of the second separator 50 is removed to place the exposed right portion of the second adhesive layer 40 on the display. Then, the left portion of the film A is lifted to detach from the display, and the left portion of the separator 30 is torn from the slit S to expose the left portion of the adhesive layer 20 to be placed on the left portion of the display. The right portion of the separator 30 is removed in the same manner and the adhesive layer 20 is placed on the display to complete the installation. A significant advantage of this embodiment is to provide the cleaning function to the film A, because any remaining dust or particles on the display are removed by the second adhesive layer 40 temporarily placed on and removed from the display.
This invention was described and explained as above; however, embodiments of this invention are not limited to the above-embodiments, and many modifications and arrangements are possible. For example, the disposable area P2 can be in any shape and not limited to the above-examples. Slits can be formed in a various way such as by perforating and cutting in a V-shape. The second slit T can be perforated. Also, for example, the film A in the seventh embodiments can be applied to preceding embodiments. The adhesive layer can be formed by many different materials such as a viscoelastic material and adhesive material. Furthermore, the shape of the film sheet A is not limited to rectangular and can be any shape to confirm with the display. Furthermore, any guide mean can be provided in the separator 30 to facilitate to place the film A on an appropriate place. In addition, the first and second separators 30, 50 or any alternative separators can be used to accomplish the cleaning function only.
While the embodiments of the present invention disclosed herein are presently considered to be preferred embodiments, various changes and modifications can be made without departing from the spirit and scope of the present invention. The scope of the invention is indicated in the appended claims, and all changes that come within the meaning and range of equivalents are intended to be embraced therein.
Number | Date | Country | Kind |
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2010-15990 | Jan 2010 | JP | national |
2010-168330 | Jul 2010 | JP | national |
2010-254917 | Nov 2010 | JP | national |
The present application is a continuation application of previously filed continuation-in-part application U.S. Ser. No. 15/445,912 filed on 2017 Feb. 28, and claims the benefit under 35 U.S.C. section 119(a) of Japanese Patent Application filed in the Japan Patent Office on Nov. 15, 2010 and assigned serial number 2010-254917, Japanese Patent Application filed in the Japan Patent Office on Jul. 27, 2010 and assigned serial number 2010-168330 and the Japanese Patent Application filed in the Japan Patent Office on Jan. 7, 2010 and assigned serial number 2010-15990, and further to U.S. patent application Ser. No. 12/961,093, filed Dec. 6, 2010, the disclosures of which is incorporated herein by reference.
Number | Date | Country | |
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Parent | 15445912 | Feb 2017 | US |
Child | 16675144 | US |
Number | Date | Country | |
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Parent | 12961093 | Dec 2010 | US |
Child | 15445912 | US |