GB2503992A - Screen protector film for smart-phone with a rear facing projection or marker for locating a button that is covered by the film - Google Patents

Abstract

A screen protector 2 for a portable electronic device 1, such as a smart phone or tablet computer having a preferably touch-sensitive display screen 21 comprises a flexible plastic film 3 suitable for application, preferably using adhesive 5, across the face of the device having the screen. The film covers substantially the whole face of the device including any control push buttons. The film 22 includes features allowing it to also cover peripheral areas of the device face outside and bordering the screen area, these peripheral areas of the face including one or more press buttons 23, such as is found on the face of the iPhone (RTM) smart-phone. The film area over the screen 21 is transparent (fig 2), while the peripheral area may be opaque preferably from a coloured layer 4 which may be ink. At the position of the button, the overlying film may comprise a visual marker 41 for the button position. Additionally or alternatively there may be a tactile marker for the button position. The film at the button position 23 may additionally or alternatively be deformed by an embossing process so that it projects downwards relatively towards the device face (see fig 3). The projecting embossed area of the film over the button may conform with a concave button profile. Additionally or alternatively, the film may carry a projecting element 6 that contacts the button when the film is applied. Cut-out regions 34, 35, 36 of the film may be arranged to provide holes for a speaker, camera etc.

Description

SCREEN PROTECTORS

This application has to do with screen protectors for use on electronic devices having touch-sensitive display/control screens, particularly but not exclusively portable or hand-held devices.

BACKGROUND

In recent years the use of hand-held or portable electronic devices with touch screen control and display has increased widely, in respect of mobile telephones (cell phones) , music storage and reproduction devices, GPO navigation devices, internet access devices, general-purpose personal computing devices and devices combining various of the above functions. Examples of these are the well-known iPhone®, iPad® and iPod® touch-responsive devices made by Apple Corporation. A feature of such devices is that the front display face of the device includes a touch-sensitive screen region, operable both to display (output) data and control symbols and to receive (input) touch control operations from the user, and also a border region of the front face which is not touch-sensitive. The border region may form a frame or surround for the touch-sensitive screen, usually not itself having any control or display function.

In many such devices the surface of this border region is flush and/or continuous with the surface of the touch screen portion, e.g. because a single cover piece of the device body forms both. The touch screen area of the cover piece is transparent for the display/control beneath. The border region may be opaque or blank.

A further feature of many such devices is the presence of non-touch-sensitive output or input elements on the front display face, such as audio speakers, microphones, camera lenses, light sensors or emitters, and button controls to supplement the touch-sensitive input and electronic screen display output. Many devices feature a mechanical push-button in the border region, often recessed relative thereto, to actuate a "home" or "reset" function by which the user can return the status cf the device quickly tc a standard initial state.

To protect the screen display face against damage, particularly against scratching, it is known to provide (as an accessory) a screen protector in the form of a plastics film shaped to fit the front face of the device body -especially, over both the touch sensitive area and over a flush adjacent border region. The rear film surface is covered with a releasable (peelable) pressure-sensitive adhesive to hold it on to the device's face. Touch input to the touch screen is still effective through the adhered transparent film. Holes are cut for border region input or output elements such as the home or reset button, audio speaker etc. If the protective film is scratched it can be removed and replaced.

These films work well, but their initial application requires care and deftness to avoid trapping bubbles which are unsightly and affect touch input. It has been proposed (see US8,044,942B) to provide the adhesive only on a border region of the film, corresponding to the border region of the device body, with a spacer frame between the film and adhesive so that the display region of the film is held clear of the device display unless pushed into contact by a user's finger.

In these peelable adhesive screen protectors, a through-hole is provided for access to the home button or recess button, because this button must be positively pushed down rather than merely touched in order to operate the device. There tends to be accumulation of dirt at this through-hole because of the exposed film edge, adjacent adhesive and frequent finger contact.

THE INVENTION

The invention provides a novel screen protector for a portable electronic device of the kind described, i.e. having a front display face with a touch-sensitive display and control screen and an adjacent border region.

A first aspect of the invention relates to a screen protector for a device of the kind described having a push button in the border region, such as a home button or reset button, and which button usually is flush with or recessed into the front face of the device body. The screen protector consists essentially of a flexible plastics film having a front face and rear face, with a layer of adhesive on the rear face to stick it onto the front display face of the device. The plastics film has a transparent display region to overlie the touchscreen region of the device body, and a border region to overlie the front display face border of the device body. Desirably the screen protector film has a periphery shaped to conform to a front periphery of the front display face of the device -typically, a generally rectangular format -so that it may cover all or substantially all of that front display face. Tn the first aspect of the invention the screen protector is characterised in that the film extends over a button region thereof, overlying the mentioned push button of the device in use, and at the button region the screen protector has a rearward projection, localised in the button region, to engage the top of the device's push button in use.

We prefer that the button region of the screen protector film is debossed, i.e. formed with a rearward indentation of the film. This may be at substantially constant thickness, i.e. the indented part projects out substantially as far at the rear surface as the front surface is indented at the front. Its rear surface may be shaped to conform with the top surface of the push-button of the device and/or with the conformation of a seating recess (if any) of such a push button. Thus, the indentation may have for example a generally circular, oval or rectangular outline. It may have a generally dished conformation, i.e. the slope of the indentation decreasing progressively from its edge to its centre.

Such a rearward indentation may conveniently be formed by a stamping or pressing method using a stamp or press element shaped with the form of the desired indentation, and preferably heated so as to promote lasting plastic deformation of the film material.

The size of the indented region depends on the dimensions of the push-button of the device with which it is to be used, but typically its maximum dimension over the film surface will be between 4mm and 25mm, more usually between 5mm and 15mm. Its maximum depth at the front surface (i.e. below the plane of the adjacent front surface) is typically from 0.2 to 2mm, more usually from 0.2 to 1mm.

Its projection at the rear surface (i.e. relative to the plane of the surrounding rear surface) is preferably from 0.1 to 2mm, more usually 0.2 to 1mm. As mentioned, the film may substantially maintain its thickness at this point, subject to some slight thinning due to stretching if the indentation has been created by stamping or pressing as is usual.

Additionally or alternatively, at the button region a projection piece may be attached to the rear surface of the film, localised at or within the button region. This may be for example an adhered piece, e.g. a printed element cured or dried in place (preferred) , or an adhered piece such as a shaped piece of film. Most preferably such a projection piece is used in conjunction with a deboss as described above to enhance the rearward reach' of the button region of the screen protector, having in mind that the films suitable for such screen protectors are naturally strong and not very extensible. The projection piece may be positioned generally centrally in the button region, and generally centrally relative to a debossed portion if one is present.

The rearward thickness of the projection piece is desirably at least 0.05mm, preferably at least 0.1mm or at least 0.2mm. Usually it will not be more than 2mm, or not more than 1mm, or especially not more than 0.5mm but of course this depends on the surface conformation of the device body, the push button face and degree of recessing, also on the defcrmability of the film and on whether a debcss is provided. As for its shape in the plane of the film, this is not critical but may be circular or polygonal e.g. square or rectangular. It may be generally concentric and/or congruent with a debossed portion.

The home button or reset button of the device is often recessed, and is marked, so as to be easily located both by sight and by touch. To maintain this facility, in the present screen protector the button region may be distinguished from the surrounding border region by some pattern or tonal contrast indicating the position of the button region. Additionally or alternatively, the front surface of the film may have some shape formation enabling location by touch. Desirably this is an indentation formed by a deboss as discussed above, since this is a familiar form for the button. However different formations may be used, e.g. a local projection, or ring, or set of projections, or a distinctive surface texture of the film specific to the button position enabling location by touch.

From the above, it will be understood that the first aspect of the present invention has the advantage of covering and protecting the push button of the device body.

It avoids the accumulation of dirt and the exposing of the film edge encountered in the known protectors, while maintaining the characteristic operation and identifiability of the button.

In a second aspect of our proposals the screen protector is charaoterised in that again the film extends over the button region thereof, to overlie the functional push-button of the device in use, and in that at the button region the screen protector has a visual and/or tactile (conformational) marker for the button. The protector is adapted if necessary so that when a user presses on the marked button region, the device button beneath is operated.

The form, e.g. three-dimensional shaping, of the screen protector button region may be adapted to conform to the form of the function button of the device beneath. The function button (in its rest position) may be recessed into the front face of the device, flush with the front face of the device or stand above the front face of the device, Of course it will recede to some extent when pressed. Thus, the button region of the screen protector may be formed with a corresponding depression, deboss or rearward projection, or an eminence or boss or rearward concavity, corresponding to the form of the button, either supplementary to or integral with the film substrate of the screen protector.

Cr, it and its film thereof may be flat over the button region. Where there is three-dimensional forming of the touch protector screen, as in a boss or deboss, this in itself is a tactile marker for the position of the button.

Where there is no boss or deboss, as proposed in the first aspect above a tactile marker can still be provided, e.g. by one or more local front projections, indentations or surface characteristic texture, other than a general eminence or depression of the film.

7dditionally or alternatively, and particularly but not exclusively in case there is no local conformation change or other tactile marker at the button region of the film, a visual marker is provided. Preferably this is by a local colour marker or colour contrast marker corresponding to the form of the button, to overlie the button. This may be by means of a colour layer applied e.g. by printing to the film, e.g. to the reverse thereof as described for the third aspect below. Preferably the colour or colour contrast marker for the button is designed to match or correspond to the appearance of the underlying button itself, to reassure the user who may be familiar primarily with the appearance with the buttons on the device per se. It is usually a contrasting patch.

In preferred constructions the border region of the screen protector has a surround or background colour, colour tone or general pattern which prevails over the border region thereof, or over at least a part of the border region having the button or buttons, and the button region has a contrasting button colour, colour tone or colour tone pattern which may also be opague.

Alternatively one or other of the button region and the

background border region may be colourless and/or

transparent to give the contrast, e.g. by making the actual button visible through a correspondingly-shaped window.

Irrespective of whether the button is recessed, flush or stand proud of the device body it is optional that a rearward projection may be provided on the rear surface of the film, localised at (and preferably localised within) the button region to enhance the press action of the user's thumb or finger on the button, i.e. to direct force more selectively onto the button, countering a possible tendency for the presence of the touch protector film to distribute applied force to areas around the button.

Preferably the border region of the screen protector is opaque (although it may have one or more non-opaque windows or cut-out regions to expose or mark particular device features) . Preferably the opague border region defines a frame around the transparent display region. The opaque region can be created by printing a colouring agent or ink in the desired pattern onto the plastic film of the screen protector, which film is itself desirably colourless as well as transparent. The colour may be selected to match the device body. Suitable polymer-based printable compositions such as water-based acrylic inks are readily available.

Desirably it is printed on to the rear surface of the plastic film, so as to be protected by it against abrasion.

The thickness of the opaque colour layer is not critical but may be e.g. from 3 pm to 25 pm, usually between 5 and 15 pm.

For ease of application of the screen protector, we prefer that the adhesive is applied only on or over the border region thereof, leaving the display region free of adhesive so that it lies un-adhered over the touch screen of the device. This eliminates concerns about bubble formation during application. Unlike the proposal in USB,044,942B, however, we find that there is no need for a spacer frame.

The screen protector functions well without a spacer frame, provided that the plastics film used is one with an anti-glare treatment at least on its rear surface to avoid the production of so-called Newton's rings between the film and screen when the film is pressed. Such adapted films are in themselves well-known and generally available: suitable materials are discussed further below. Returning to the adhesive, we prefer the use of a pressure-sensitive removable (peelable) adhesive. This is known. It can be applied in the border region/pattern by any suitable means, preferably screen printing but other transfer methods may be used. Conveniently a water-based acrylic adhesive is used.

The skilled person is able to select a suitable adhesive which is pressure-sensitive so that the screen protector film is adhered securely to the front face of the device, preferably all the way out to its periphery, and will remain reliably in place but can be peeled away carefully in case replacement is needed, without leaving significant or persistent adhesive residue on the device face.

The thickness of the adhesive layer is not critical, but typically is between 10 and 50 pm, more usually from 15 to 40 pm.

In a preferred construction the adhesive is printed directly onto the back of a colour layer as mentioned above, which in turn may be printed directly onto the back of the plastics film. The regions covered by the colour layer and adhesive may substantially correspond. The total thickness of the adhesive layer and colour layer combined is preferably less than 50 pm. That is to say, the screen region of the screen protector is scarcely or negligibly spaced from the underlying device touch screen but we find that with an anti-glare film, good visual performance is achieved.

The above-described mode of mounting and presenting the screen protector film (colour layer, adhesive layer, patterning, thickness of these, absence of frame) are an independent third aspect of the present invention, desirably used in conjunction with the first and/or second.

As mentioned, plastics films suitable for applications of this kind are known to the skilled person. They require a scratch-resistant surface and, as mentioned, desirably also an anti-glare surface. Films of this kind are widely known, often based on a polyester e.g. polyethylene terephthalate (PET) substrate film coated or treated on one or both faces. Usually the substrate film e.g. polyester film has a surface coating film made from a separate adherent crosslinked polymer e.g. of an acrylate type.

Anti-glare and scratch-resistant properties may be conferred by known combinations of microparticles or nanoparticles dispersed in the coating film. See e.g. US2003/0180520A, US2003/0174257A, US2012/0028037A and US2012/0034450A. Films of this kind, available e.g. from Kimoto Co., Ltd., are well known and widely used for covering touch-sensitive screens.

The thickness of the plastic film is usually between 0.1 and 1.5 mm. The transmission of the film (corresponding to transmission at the screen portion of the present screen protector) is typically at least 85% or at least 90% for visible light; again this is a known and readily available performance.

As provided, the screen protector preferably includes a peelable release layer covering the adhesive regions on the rear surface, removed shortly before application to the device. Such release layers, having e.g. a silicone release surface, are in themselves well-known and are not described further here.

A method of modifying an electronic device by applying the screen protector is an aspect of our proposals, as is the electronic device so modified.

An example of the present invention is now described with reference to the attached drawings, in which Fig 1 is a front view showing a screen protector of the present invention superimposed over a hand-held telephone of the iPhcne® type; Fig 2 is a section at Il-Il of Fig 1, showing the layer construction of the screen protector at side border regions thereof, with the thicknesses greatly exaggerated for clarity; Fig 3 is a similar view at 111-Ill of Fig 1 showing the screen protector layer structure at a lower border region including a button region, and Fig 4 is a side view of the device showing the position and extent of the screen protector.

Referring firstly to Figs 1 and 4, a portable telephone (mobile phone, cell phone) of the iPhone® format is shown, the device 1 having a generally rectangular flat body 15 with a back surface 151 which will not be discussed further, a peripheral surface 152 including certain controls 153 which again will not be discussed further, and a front surface covered by a single front cover plate 18 presenting a flat smooth glass or glass-like polymer surface. It should go without saying that no rights are claimed here to any of the structural aspects of the phone device 1. The present screen protector 2 is applied to the front surface of the phone device, i.e. to front plate 18 thereof.

Fig. 1 shows the front face of the screen protector 2, with characteristic zones corresponding to the well-known characteristic zones and features of the front face of the phone device 1. Thus, the device 1 has a central rectangular touch-sensitive display/control screen 11 occupying most of its area. This is surrounded by a non-illuminating, non-touch-sensitive opague border area or frame region 12 of the front plate 18. The bottom part of the border region has a circular hole in which is seated a home button' 13, for re-setting the device to an initial state. The top part of the device border region, above the tcuchscreen, has various functional elements including an audio speaker 15, a camera lens 16 and an IR emitter/sensor 24.

Ps seen in Fig 1, these feature zones are reproduced or accommodated in the screen protector 2. This consists of a piece of substrate film 3 peripherally shaped to conform exactly to the front of the device 1, and having a central transparent region 21 shaped and positioned to overlie the tcuchscreen 11 of the device 1. The film 3 in this embodiment is a PET film, available from Kimoto Co., Ltd. as N7BB, having a thickness of 0.188 mm and with hard layer and anti-glare surface treatments on both the front and rear faces. This film is known per se and commercially available.

On the rear surface of the film an opaque colour frame is printed, in a frame shape confcrming tc the non-touch-sensitive areas of the phone front plate 18. It has narrow side frame porticns 221 and broader top and bottom frame zones 223 and 222. This opaque frame region 22 is printed on as a layer 4 using a conventional colour agent, e.g. water-based acrylic ink, by a screen printing method. It is dried by hot air to a layer about 8 pm thick. A wide range of colours is available for such acrylic inks, e.g. white or black to match conventional phone fascia colours. The specified thickness is sufficiently opaque. The main colour layer 4 covers the entire border region 22 except for a button region to be discussed below, and at the top part 223 of the border region a transparent window 34 which overlies the IR emitter/sensor so that this can operate through the screen protector film. Additionally, the screen protector film has windows 35,36 positioned and shaped to overlie the audio speaker 15 and the camera lens 16 and these are fully cut-out regions i.e. there are holes through the film at these points. This is known per Se.

To stick the screen protector onto the front of the phone device 1, a pressure-sensitive peelable (removable) adhesive is printed over the colour layer 4 and the adhesive layer 5. As seen by reference to Figs 2 and 3, it covers exactly the same regions as the colour layer 4 and is superimposed directly onto the colour layer 4, except at the button region 23 where the adhesive layer 5 is absent, i.e. there is a hole in the adhesive slightly larger than the button.

In this example the button is circular, with a diameter of about 11 mm. The adhesive finishes just short of its periphery to avoid "bleed" into the gap. Suitable adhesives are readily available and known to the skilled person; that used in this embodiment is a water-based acrylic pressure sensitive adhesive 5178 (available from Kiwc Inc.), featuring a low peel strength. The thickness of the adhesive layer, applied by screen printing in this embodiment, is from 25 to 30 pm (0.025 to 0.03 mm). Thus, the combined thickness of the colour layer 4 and adhesive layer 5 in this embodiment is less than 40 pm (0.04 mm).

Figs 2 and 3 indicate that this thin layer cf ink and adhesive holds the film 3 at its periphery fractionally clear of the screen surface 11 of the device 1, but this will not prevent contact therewith. However the anti-glare surface of the film is found to avoid Newton's rings. So, by having adhesive only on the frame or border area 22 of the screen protector, application is greatly facilitated without fear of bubbles while maintaining good touch-sensitive operaticn.

Fig 1 also shows the position of a peel tab 7, indicating a removable portion where a siliconised release layer can be gripped to remove it from the rear of the film to expose the adhesive layer 5 for application.

Next, the push-button area 23 is described. As mentioned, in this device it is circular. In conventional devices the screen protector film has a corresponding hole, leaving the tcp of the button 13 exposed. In this device the film 3 continues across the button region 23, preventing the ingress of dirt or catching of the film edge at this area. See Fig 3. By the use of a heated boss during manufacture, a debossed portion, of circular dished shape and projecting rearwardly, is formed in the film at the push-button region 23. This conforms the film generally to the (correspondingly concave) top surface of the button 13 itself. At the push button region 23 the main colour layer 4 finishes and there is a distinct local colour layer 41 (printed in the same way onto the back of the film) of a contrasting colour, to mark the position of the button visually. The debossed indentation of the front of the film enables the position also to be felt in the normal way by the user's thumb or finger.

Finally, at the centre of the rear surface of the debossed portion of the film 23, a rear projection piece 6 is provided. In this embodiment it is a printed element about 4 mmby 4 mm (of oourse the exact shape is not critical) and about 0.25 mm (250 rim) thick. It is printed on using a "high-build" UV-curable ink, that is to say, an ink stands up from the substrate so as to give a significant height over a small area. Such inks are well-known per se, being used e.g. for printing Braille. So, in the event that the main film has limited stretch (as tends to be the case with the high-performance scratch-resistant films involved) this feature helps to ensure full pressing of the home button by a corresponding pressure on the push button region 23 of the screen protector.

Claims (18)

1. CLAIMS: 1. A screen prctectcr for an electronic device having a frcnt display face with a touch-sensitive display and control soreen, and an adjacent border region in which there is a push button, the screen protector consisting essentially of a flexible plastics film having a front face and a rear face, with a layer of adhesive on the rear face to stick it onto the front display face of the device, the plastics film having a transparent display region to overlie the touchscreen region of the device body, and a border region to overlie the front display face border of the device body, characterised in that the film extends over a button region thereof, to overlie the mentioned push button of the device in use, and at the button region the screen protector has a rearward projection, localised in the button region, to engage the top of the device's push button in use, and/or at the button region the screen protector has a visual and/or tactile marker for the device's push button.
2. 2. A screen protector according to claim 1 in which the button region of the screen protector film is debossed, i.e. formed with a rearward indentation of the film.
3. 3. A screen protector according to claim 2 in which the indentation has a circular, oval or rectangular outline.
4. 4. A screen protector according to claim 3 in which the indentation has a generally dished conformation, the slope of the indentation decreasing progressively from its edge to its centre.
5. 5. A screen protector according to any one of claims 2 to 4 in which at the button region the maximum depth of the indentation at the front surfaoe is from 0.2 to 2mm, its projection at the rear surface is from 0.1 to 2mm.
6. 6. A screen protector according to any one of the preceding claims in which the maximum dimension of the button region of the film over the film surface is between 5mm and 15mm.
7. 7. A screen protector according to any one of the preceding claims in which at the button region a projection piece is attached to the rear surface of the film, localised at or within the button region, to engage the device push button in use.
8. 8. A screen protector according to any one of the preceding claims in which the adhesive is applied only on or over the border region thereof, leaving the display region free of adhesive so that in use it lies un-adhered over the touch screen of the device.
9. 9. A screen protector according to any one of the preceding claims in which the plastics film has an anti-glare treatment at least on the rear surface.
10. 10. A screen protector according to any one of the preceding claims in which the border region is opaque, consisting of a colouring agent or ink printed onto the rear surface of the plastic film to form a colour layer, and the adhesive is printed onto the back of the colour layer, the tota thickness of the adhesive layer and colour layer combined being less than 50 pm.
11. 11. A screen protector according to claim 10 in which the printed regions covered by the colour layer and the adhesive substantially correspond in pattern.
12. 12. A screen protector according to any one of the preceding claims which includes a peelable release layer covering the adhesive on the rear surface, to be removed before applying the screen protector to the device.
13. 13. A screen protector according to any one of the preceding claims in which said button region is to cover a home button or reset button flush with or recessed into the front face of the device body.
14. 14. A screen protector according to any one of the preceding claims in which the adhesive is not present at the button region.
15. 15. A method of modifying an electronic device having a front display face with a touch-sensitive display and control screen, and an adjacent border region in which there is a push button, comprising applying a screen protector according to any one of claims 1 to 14 to the front display face of the device.
16. 16. A method of claim 15 in which the screen protector film has a periphery shaped to conform to a front periphery of the front display face of the device, which has a rectangular format, so that it covers all or substantially all of the front display face.
17. 17. A modified electronic device resulting from a method of claim 15 or 16.
18. 18. A screen protector, method of modifying an electronic device with a screen protector, or electronic device modified therewith, substantially as described and shown herein with reference to the accompanying drawings.